1000 Sentences With "perturbations" | Random Sentence Generator

This work shows that focusing only on defending against small perturbations is insufficient, as large, local perturbations can also break classifiers.

A recently revised study named "Universal Adversarial Perturbations" made this feature explicit by successfully testing the perturbations against a number of different neural nets — exciting a lot of researchers last month.

Suitable image perturbations are easy to reproduce and are, moreover, universal.

In Washington and Louisiana, massive L-shaped detectors sniff for invisible gravitational perturbations.

A question on many minds is whether technology can do away with such perturbations.

It has to correct for those, like gravity and atmospheric drag and other perturbations.

The sun, with all its flares and stellar perturbations, is not a totally spherical object.

If you can modulate it with a few simple perturbations, that's the definition of a program.

They can fall one way or the other with very small perturbations, as we just saw.

This includes adding "random geometric perturbations to the watermark" — effectively warping the text and logos being used.

But, as we shall show, this vertical motion of the hanging ponytail is unstable to lateral perturbations.

Tiny perturbations in the gas then started to grow by force of gravity, eventually forming stars and galaxies.

The video runs from August 2015 to July 2016, capturing the ever-changing perturbations of the Earth's weather systems.

Near this point, the dynamics is chaotic, so the paths of small particles are highly sensitive to small perturbations.

There are already plenty of ways to hack self-driving cars, for example, that don't rely on calculating complex perturbations.

The similarity here between the different perturbations means that the same basic idea generalizes well across the various classification networks.

The second is that their higher surface gravity makes it harder to have such large surface perturbations [dynamic topological features].

We can... pick a font vector and generate new fonts from random perturbations... We can also generate completely new fonts.

For one thing, atoms don't tend to sit still very well given the thermal perturbations found at most reasonable temperatures.

The stock market tends to overreact to perturbations like these, just as it did to Greek concerns in 2014 and 2015.

And that assumption directly affects scientists' estimates of how sensitive the Earth's climate is to perturbations, such as increased greenhouse gases.

They are highly coupled in the sense that perturbations to one component can lead to rapid change in that system's entire operation.

The AIA 193 channel picks up the cooler, outer atmosphere of the Sun, revealing the magnetic perturbations of the star in gold.

The short blurbs outside each gallery room make bland attempts at encapsulating the region's tumultuous history and current democratic and militaristic perturbations.

That contradicts a report that seems to have originated in Scientific American that says small perturbations are occurring on the craft right now.

This will either validate or complicate the hypothesis that the dwarf galaxy is the main driver of the Milky Way's outer disk perturbations.

The researchers devised a more effective way to simulate the complexity of the real world by adding noise, or perturbations to their simulation.

These perturbations were first described in 2013, and in a 2014 paper titled "Explaining and Harnessing Adversarial Examples," researchers demonstrated how flexible they were.

In terms of how these systems form, it's thought that gravitational perturbations within the protoplanetary disk causes the dense material within it to fragment.

Both 2I/Borisov and 'Oumuamua formed in other planetary systems and were ejected by gravitational perturbations into interstellar space as orphans wandering the cosmos.

The atmosphere is too complicated, too fragile, too sensitive to small perturbations, to submit to the equations with the precision of planets or stars.

In 2014, they released a paper showing that "imperceptible perturbations" in a picture could force state-of-the art recognition algorithms to misclassify an image.

" The organization added: "No evidence of perturbations due to solar radiation pressure is seen, and no link to a known artificial object has been found.

To do this, the researchers had to make their perturbations more "robust," that is, create manipulations that can fool a wider array of systems, including humans.

But few forces in life are more powerful than mean reversion — the tendency of long-run averages to reassert themselves despite the perturbations of the present.

This huge geographic range allows the team to hone in on the signal by correcting for errors in the instrument or perturbations in Earth's atmosphere, Koopmans said.

Some of those choices, if they happen at just the right moment, could be just the perturbations that spark cascading changes in social, economic, or technological systems.

The instrument is so sensitive, in fact, that it must be sealed in a vacuum so that it can pick up the tiniest perturbations in the Martian crust.

Like ripples on a galactic pond, gravitational waves are pulsating perturbations or ripples in the very fabric of space and time, caused by the motion of massive objects.

"The brain, by way of attention lapses and micro-sleeps, is just as sensitive as the heart to very small perturbations of sleep," Walker explains in his book.

As shown in "Universal Adversarial Perturbations," what fools one neural network 90 percent of the time, may only have a success rate of 50 or 60 percent on a different network.

And to folks like us, who know the polling game and can sort out real trends from normal perturbations, too many of this year's polls, and their coverage, have been cringeworthy.

Unlike the black holes, which were only detected by tiny perturbations in a giant laser system, the neutron star collision also produced light that could be detected with an optical receiver.

Pandora and its partner moon, Prometheus (not pictured), are responsible not only for feeding material into the F Ring, but small perturbations that result in small, wave-like kinks in its shape.

He looked at this problem by dividing the disk into an infinite number of single rings of particles around the center and calculated how small jostles, called "perturbations," would affect the rings.

I haven't seen, for instance, any remotely acceptable reason why marine life could not evolve intelligence and civilization—and marine habitats are much less susceptible to perturbations of climate than land ecosystems.

These either leave organic traces in the brain that, though not always accessible before a patient's death, are characteristic of the condition in question, or cause recognisable perturbations of things such as electroencephalograms.

Quantum satellites aren't some far-fetched idea—sending quantum information in a practical sense almost demands the medium of space for the simple reason that optical channels are highly sensitive to atmospheric perturbations.

They approach climate damages as minor perturbations around an underlying path of economic growth, and take little account of the fundamental destruction that we might be facing because it is so outside humanity's experience.

"The fact that they have such tiny little distributions—each one has a small pocket like a bay or an archipelago—makes them just intrinsically susceptible to large perturbations and extinction events," Erdmann said.

But as it was traveling out of sight, small perturbations in its motion suggested that in fact the rock was actually a comet, being pushed around by jets of gas shooting from its surface.

I suppose it is straightforward, but my hypothesis is that people forced to muffle their feelings and thoughts are in peril of burying those inner perturbations so deeply that they can't unearth them anymore.

Some of the specific numbers differ, since quantum mechanics describes how particles evolve based on their position and energy, while Batygin's equation describes how perturbations evolve based on a disk system's angular momentum and density.

The stars were likely big and heavy, and surrounded by lots of material—some of which managed to escape owing to the many gravitational perturbations caused by the two stars in close proximity to each other.

"If you start in a functional range of motion under control and create perturbations your body can handle, then you're going to improve very rapidly because that's what our bodies are good at: adaptation," says Guyett.

More importantly, the higher return velocity really reduced opportunities for the rocket to correct itself in the event of unexpected factors like wind shear and atmospheric fluctuations — small perturbations that at this scale can have significant effects.

Around the world, astrophysicists can be found in labs, developing ever more sophisticated set-ups using sound waves that travel just like light waves in strong gravitational fields, or magnets to trigger perturbations in fluids and gases.

That's the case, in brief, for betting on continued stasis, and for interpreting our moment's perturbations — Trump, Comey and all — as pointing toward a real crisis for the West that still lurks a generation or more ahead.

For example, making the coupling between two oscillators in the cluster unidirectional instead of mutual not only doesn't disturb the cluster's synchrony, it actually makes its state more robust to noise and perturbations from elsewhere in the network.

This new meteorite, named Öst 65, could help scientists learn more about the history of the solar system, including any small perturbations in the orbits of planets around the sun, according to a new study in the journal Nature Communications.

"These traffic waves arise from small perturbations in a uniform traffic flow, like a bump in the road, or a driver braking after a moment of inattention," says Benjamin Seibold, a mathematician at Temple University who's worked with colleagues on understanding the phenomenon.

"The hope is that as the company matures, and its leaseholds age, they will turn profitable, but this is a model built on a knife's edge that, by design, will be sensitive to the smallest economic perturbations," he said in a blog post.

These perturbations are chosen so that every time the trajectory starts to escape, it's recaptured: not by giving the state a push, but by modifying the system and moving the attractor, so the state finds itself back on the in-set of the periodic trajectory.

So far, most exoplanets have been discovered indirectly, deduced by slight perturbations in the light traveling from a star — by a slight dimming when the exoplanet passes between its star and Earth, or by wobbles in the light's wavelengths caused by the gravitational pull of an unseen exoplanet.

"Climate change will have wide-ranging implications for US national security over the next 20 years through global perturbations, increased risk of political instability, heightened tensions between countries for resources, a growing number of climate-linked humanitarian crises, emergent geostrategic competitive domains and adverse effects on militaries," the blocked testimony stated.

The perturbations that cause a moist early spring like the one Dallas had in 223, favoring mosquito reproduction, can equally cause devastating floods — like the wall of water that swept through central Texas in May 23 and killed 21867 people — that will scour mosquito eggs from wherever they have been laid.

" Dr. McEwen discussed allostatic load in 19933 in the journal Neuropsychopharmacology, writing: "In anxiety disorders, depressive illness, hostile and aggressive states, substance abuse and post-traumatic stress disorder (PTSD), allostatic load takes the form of chemical imbalances as well as perturbations in the diurnal rhythm, and, in some cases, atrophy of brain structures.

Aside from the technical difficulties of getting enough of the right data for Liu's approach to work, some scientists have more fundamental conceptual reservations—ones that tap into a much larger question: Are changes in the composition of a microbial community mainly due to the interactions between the microbes themselves, or to the perturbations in their environment?

"We have here provided the clearest evidence that our own Galaxy disk has suffered from perturbations, bringing it to an out-of-equilibrium state, which may well be due to the interaction with an external satellite galaxy," write the authors, led by Teresa Antoja from the Universitat de Barcelona in Spain, in the paper published last week on the arXiv preprint server.

While researchers have no direct evidence of the object, they did see strange perturbations in the orbits of objects deep in the Kuiper Belt — the group of icy bodies in Pluto's part of space — that seem to suggest the existence of a planet one to 10 times more massive than Earth that orbits the sun every 10,20163 to 20,000 years.

Analogous results are known for lambdavac perturbations of the de Sitter lambdavacuum (Helmut Friedrich) and for electrovacuum perturbations of the Minkowski vacuum (Nina Zipser).

Further \varphi(z) is the complex valued amplitude of the infinitesimal streamfunction perturbations applied to the base flow, k is the wavenumber of the perturbations and c is the phase speed with which the perturbations propagate in the flow direction. The prime denotes differentiation with respect to z.

They are continuously changing due to solar and planetary perturbations.

In these methods, it is considered that the body is always moving in a conic section, however the conic section is constantly changing due to the perturbations. If all perturbations were to cease at any particular instant, the body would continue in this (now unchanging) conic section indefinitely; this conic is known as the osculating orbit and its orbital elements at any particular time are what are sought by the methods of general perturbations. General perturbations takes advantage of the fact that in many problems of celestial mechanics, the two-body orbit changes rather slowly due to the perturbations; the two-body orbit is a good first approximation. General perturbations is applicable only if the perturbing forces are about one order of magnitude smaller, or less, than the gravitational force of the primary body.

A Michelson Interferometer that is unchirped and inherently insensitive to mechanical perturbations.

In mathematics, structural stability is a fundamental property of a dynamical system which means that the qualitative behavior of the trajectories is unaffected by small perturbations (to be exact C1-small perturbations). Examples of such qualitative properties are numbers of fixed points and periodic orbits (but not their periods). Unlike Lyapunov stability, which considers perturbations of initial conditions for a fixed system, structural stability deals with perturbations of the system itself. Variants of this notion apply to systems of ordinary differential equations, vector fields on smooth manifolds and flows generated by them, and diffeomorphisms.

Orbit models are typically propagated in time and space using special perturbation methods. This is performed by first modeling the orbit as a Keplerian orbit. Then perturbations are added to the model to account for the various perturbations that affect the orbit. Special perturbations can be applied to any problem in celestial mechanics, as it is not limited to cases where the perturbing forces are small.

In this region, clouds are usually absent, as significant weather perturbations also are.

Neither canalisation nor robustness are simple quantities to quantify: it is always necessary to specify which trait is canalised (robust) to which perturbations. For example, perturbations can come either from the environment or from mutations. It has been suggested that different perturbations have congruent effects on development taking place on an epigenetic landscape. This could, however, depend on the molecular mechanism responsible for robustness, and be different in different cases.

Perturbation theory, which deals with small perturbations from e.g. a homogeneous metric, only holds as long as the perturbations are not too large, and N-body simulations use Newtonian gravity which is only a good approximation when speeds are low and gravitational fields are weak.

Smaller irregularities in the times are caused by perturbations of the Moon and the other planets.

Conversely, mutational robustness may evolve as a byproduct of natural selection for robustness to environmental perturbations.

Resonant magnetic perturbations (RMPs) are a special type of magnetic field perturbations used to control burning plasma instabilities called edge- localized modes (ELMs) in magnetic fusion devices such as tokamaks. The efficiency of RMPs for controlling ELMs was first demonstrated on the tokamak DIII-D in 2003.

ViroStatics srl develops drugs to overcome the underlying cellular perturbations common to cancer and viral diseases - dysregulation of cellular transcription and uncontrolled cell proliferation. To this end, ViroStatics has focused on selectively targeting the Cyclin Dependent Kinases (CDKs) involved in these perturbations (CDK9 and CDK4/6).

In the task of object class categorization, the ability of detecting similar regions given intra-class variation and image perturbations across object instance is very critical. Repeatability measures over intra- class variation and image perturbations is proposed. The following subsection will introduce the definition and discuss the performance.

Telescopic observations remained important for the outer planets because of their distance, hence the inability to bounce radar off of them, and the difficulty of parking a spacecraft near them. The perturbations of 300 asteroids were included, vs DE118/DE200 which included only the five asteroids determined to cause the largest perturbations. Better values of the planets' masses had been found since DE118/DE200, further refining the perturbations. Lunar Laser Ranging accuracy was improved, giving better positions of the Moon.

Moreover, this enables less current perturbations (vibrations) in the gate (due to the disposition of electrons inside the metal).

Making little perturbations with the tip of a hair, one can see whether shock waves are compressive or undercompressive.

In astronomy, the variation of the Moon is one of the principal perturbations in the motion of the Moon.

Equilibrium fluctuations of the system can be related to its response to external perturbations via the Fluctuation- dissipation theorem.

In 1902, James Jeans found the length scale required for gravitational perturbations to grow in a static nearly homogeneous medium.

Because the different species interact, changes in populations affect one another synergistically to determine community structure. Under both states the environmental conditions are identical. Because the states have resilience, following small perturbations (e.g., changes to population size) the community returns to the same configuration while large perturbations may induce a shift to another configuration.

Inflation predicts that the structures visible in the Universe today formed through the gravitational collapse of perturbations that were formed as quantum mechanical fluctuations in the inflationary epoch. The detailed form of the spectrum of perturbations, called a nearly-scale-invariant Gaussian random field is very specific and has only two free parameters. One is the amplitude of the spectrum and the spectral index, which measures the slight deviation from scale invariance predicted by inflation (perfect scale invariance corresponds to the idealized de Sitter universe).Perturbations can be represented by Fourier modes of a wavelength.

The term metastable free flow means that when small perturbations occur in free flow, the state of free flow is still stable, i.e., free flow persists at the bottleneck. However, when larger perturbations occur in free flow in a neighborhood of the bottleneck, the free flow is unstable and synchronized flow will emerge at the bottleneck.

Sigurdson is known for his work on the effects of dark matter interactions on cosmological perturbations,What Mass Are the Smallest Protohalos?.

They are called Newtonian gauges because \Psi is the Newtonian gravitational potential of classical Newtonian gravity, which satisfies the Poisson equation abla^2\Psi=4\pi G\rho for non- relativistic matter and on scales where the expansion of the universe may be neglected. It includes only scalar perturbations of the metric: by the scalar- vector-tensor decomposition these evolve independently of the vector and tensor perturbations and are the predominant ones affecting the growth of structure in the universe in cosmological perturbation theory. The vector perturbations vanish in cosmic inflation and the tensor perturbations are gravitational waves, which have a negligible effect on physics except for the so-called B-modes of the cosmic microwave background polarization. The tensor perturbation is truly gauge independent, since it is the same in all gauges.

This may be the result of perturbations from the companion star removing material from the outer regions of the Upsilon Andromedae A system.

The other free parameter is the tensor to scalar ratio. The simplest inflation models, those without fine-tuning, predict a tensor to scalar ratio near 0.1. Inflation predicts that the observed perturbations should be in thermal equilibrium with each other (these are called adiabatic or isentropic perturbations). This structure for the perturbations has been confirmed by the Planck spacecraft, WMAP spacecraft and other cosmic microwave background (CMB) experiments, and galaxy surveys, especially the ongoing Sloan Digital Sky Survey. These experiments have shown that the one part in 100,000 inhomogeneities observed have exactly the form predicted by theory.

This periodic nature led to the discovery of Neptune in 1846 as a result of its perturbations of the orbit of Uranus. On-going mutual perturbations of the planets cause long-term quasi-periodic variations in their orbital elements, most apparent when two planets' orbital periods are nearly in sync. For instance, five orbits of Jupiter (59.31 years) is nearly equal to two of Saturn (58.91 years). This causes large perturbations of both, with a period of 918 years, the time required for the small difference in their positions at conjunction to make one complete circle, first discovered by Laplace.

Topological insulators only have short-ranged entanglements and have no topological order, while the topological order defined in this article is a pattern of long-range entanglement. Topological order is robust against any perturbations. It has emergent gauge theory, emergent fractional charge and fractional statistics. In contrast, topological insulators are robust only against perturbations that respect time-reversal and U(1) symmetries.

Feedback from one year's frost heave influences the effects in subsequent years. For example, a small increase in overburden will affect the depth of ice formation and heaving in the subsequent years. Time-dependent models of the frost heave indicate that over a long enough period the short-separation perturbations damp out, while mid-range perturbations grow and come to dominate the landscape.

The growth rates of bred vectors in the Lorenz system. Red indicates the fastest-growing bred vectors while blue the slowest. In applied mathematics, bred vectors are perturbations, related to Lyapunov vectors, that capture fast-growing dynamical instabilities of the solution of a numerical model. They are used, for example, as initial perturbations for ensemble forecasting in numerical weather prediction.

To keep this highly sensitive to perturbations planetary system stable, no additional giant planets can be located within 30 AU from the parent stars.

In 2000 he gave a plenary lecture (Adiabatic perturbations of linear periodic problems) at the annual meeting of the German Mathematical Society in Dresden.

In astronomy, rotational Brownian motion is the random walk in orientation of a binary star's orbital plane, induced by gravitational perturbations from passing stars.

Our general setting features stochastic approximations of the cocoercive operator and stochastic perturbations in the evaluation of the resolvents of the set-valued operator.

The Astronomical Computing Bureau, Columbia University, performed astronomical calculations representing the state of the art in computing.. Chapter XII is "The Computation of Planetary Perturbations".

Hypocorrective sound change occurs when a listener fails to identify and correct the perturbations in the speech signal and takes the signal at face value.

As the perturbation increases and the smooth curves disintegrate we move from KAM theory to Aubry–Mather theory which requires less stringent hypotheses and works with the Cantor-like sets. The existence of a KAM theorem for perturbations of quantum many-body integrable systems is still an open question, although it is believed that arbitrarily small perturbations will destroy integrability in the infinite size limit.

The orbit of 15 Eunomia places it in a 7:16 mean-motion resonance with the planet Mars. Eunomia is used by the Minor Planet Center to calculate perturbations. The computed Lyapunov time for this asteroid is 25,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets. Eunomia has been observed occulting stars three times.

Among his best known mathematical works are "Versal deformations of equivariant vector fields for cases of symmetry of order two and three" (Ph.D. thesis, 1979), "On the number of limit cycles in perturbations of quadratic Hamiltonian systems" (joint with I. D. Iliev), "Some functions that generalize the Krall-Laguerre polynomials" (joint with F. A Grünbaum and L. Haine), and "Perturbations of the spherical pendulum and Abelian integrals".

Every 18 years, the asteroid 197 Arete approaches within of Vesta. In 1966, based upon observations of Vesta's gravitational perturbations of Arete, Hans G. Hertz estimated the mass of Vesta at solar masses. More refined estimates followed, and in 2001 the perturbations of 17 Thetis were used to calculate the mass of Vesta to be solar masses. Dawn determined it to be solar masses.

The first and second assumptions are expressed explicitly in the derivation of quasi-geostrophic PV. Leading-order geostrophic balance is used as the balancing condition. The second-order terms such as ageostrophic winds, perturbations of potential temperature and perturbations of geostrophic height should have consistent magnitude, i.e., of the order of Rossby number. The reference state is zonally averaged potential temperature and geopotential height.

Standing posture relies on dynamic rather than static balance. The human center of mass is in front of the ankle, and unlike in tetrapods, the base of support is narrow, consisting of only two feet. A static pose would cause humans to fall forward onto the face. In addition, there are constant external perturbations, such as breezes, and internal perturbations that come from respiration.

Much of the difficulty, and many of the disputes, in understanding the large-scale structure of the universe can be resolved by better understanding the choice of gauge in general relativity. By the scalar-vector-tensor decomposition, the metric includes four scalar perturbations, two vector perturbations, and one tensor perturbation. Only the scalar perturbations are significant: the vectors are exponentially suppressed in the early universe, and the tensor mode makes only a small (but important) contribution in the form of primordial gravitational radiation and the B-modes of the cosmic microwave background polarization. Two of the four scalar modes may be removed by a physically meaningless coordinate transformation.

Sunyaev and Yakov B. Zeldovich developed the theory for the evolution of density fluctuations in the early universe. They predicted the pattern of acoustic fluctuations that have been clearly seen by WMAP and other CMB experiments in the microwave sky and in the large-scale distribution of galaxies. Sunyaev and Zeldovich stated in their 1970 paper, "A detailed investigation of the spectrum of fluctuations may, in principle, lead to an understanding of the nature of initial density perturbations since a distinct periodic dependence of the spectral density of perturbations on wavelength (mass) is peculiar to adiabatic perturbations." CMB experiments have now seen this distinctive scale in temperature and polarization measurements.

Quasinormal modes (QNM) are the modes of energy dissipation of a perturbed object or field, i.e. they describe perturbations of a field that decay in time.

The present study examines the processes that occur in circumterrestrial space during magnetic perturbations by creating new algorithms and techniques for recognition, analysis, and interpretation of data.

As the Hubble radius grows in the expanding universe, it encompasses larger and larger disturbances. During matter domination, all causal dark matter perturbations grow through gravitational clustering. However, the shorter-wavelength perturbations that are included during radiation domination have their growth retarded until matter domination. At this stage, luminous, baryonic matter is expected to mirror the evolution of the dark matter simply, and their distributions should closely trace one another.

IX Special perturbations can be applied to any problem in celestial mechanics, as it is not limited to cases where the perturbing forces are small. Once applied only to comets and minor planets, special perturbation methods are now the basis of the most accurate machine-generated planetary ephemerides of the great astronomical almanacs.See, for instance, Jet Propulsion Laboratory Development Ephemeris. Special perturbations are also used for modeling an orbit with computers.

The Glasser effect describes the creation of singularities in the flow field of a magnetically confined plasma when small resonant perturbations modify the gradient of the pressure field.

It was shown that in non-local gravity, Schwarzschild singularities are stable to small perturbations. Further stability analysis of black holes was carried out by Myung and Park.

Small perturbations, imposed at the inlet on the tangential velocity, evolve in the computational box. High Reynolds number would be marked with an increase of small scale motions.

Therefore, its density perturbations can grow first. The resulting gravitational potential acts as an attractive potential well for ordinary matter collapsing later, speeding up the structure formation process.

The grave of Urbain Le Verrier. Le Verrier began studying the motion of Mercury as early as 1843, with a report entitled Détermination nouvelle de l ’orbite de Mercure et de ses perturbations (A New Determination of the Orbit of Mercury and its Perturbations). In 1859, Le Verrier was the first to report that the slow precession of Mercury’s orbit around the Sun could not be completely explained by Newtonian mechanics and perturbations by the known planets. He suggested, among possible explanations, that another planet (or perhaps, instead, a series of smaller 'corpuscules') might exist in an orbit even farther to the Sun than that of Mercury, to account for this perturbation.

It is also important to note that because the degree of cortical reorganization is proportional to phantom limb pains, any perturbations to the amputated regions may increase pain perception.

The title of his doctoral dissertation is "Unitary Perturbations of Contractions", supervised by Marvin Rosenblum. According to current Mathematics Genealogy Project database, Ball has 12 students and 18 descendants.

Pallene is visibly affected by a perturbing mean-longitude resonance with the much larger Enceladus, although this effect is not as large as Mimas's perturbations on Methone. The perturbations cause Pallene's osculating orbital elements to vary with an amplitude of about 4 km in semi-major axis, and 0.02° in longitude (corresponding to about 75 km). Eccentricity also changes on various timescales between 0.002 and 0.006, and inclination between about 0.178° and 0.184°.

Quantum key distribution exploits certain properties of quantum physics to ensure its security. It relies on the fact that observations (or measurements) of a quantum state introduces perturbations in that state. Over many systems, these perturbations are detectable as noise by the receiver, making it possible to detect man-in-the-middle attacks. Beside the correctness and completeness of quantum mechanics, the protocol assumes the availability of an authenticated channel between Alice and Bob.

Ordinary matter is affected by radiation, which is the dominant element of the universe at very early times. As a result, its density perturbations are washed out and unable to condense into structure. If there were only ordinary matter in the universe, there would not have been enough time for density perturbations to grow into the galaxies and clusters currently seen. Dark matter provides a solution to this problem because it is unaffected by radiation.

The secondary star is likely a red dwarf from its low mass. In 2009, the system was hypothesized to contain an exoplanet based on perturbations in the orbital period. A prograde solution was quickly ruled out but a retrograde solution remains a possibility, although the variations may instead be due to the secondary star being itself a close binary, since the formation of a planet in such a system would difficult due to dynamic perturbations.

The computed Lyapunov time for this asteroid is 20,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.

Evolution of an Airy beam. An Airy beam, is a propagation invariant wave whose main intensity lobe propagates along a curved parabolic trajectory while being resilient to perturbations (self-healing).

The Sun's motion about the centre of mass of the Solar System is complicated by perturbations from the planets. Every few hundred years this motion switches between prograde and retrograde.

Numerous studies demonstrated how global substitution of canonical amino acids with various isosteric analogs caused minimal structural perturbations but dramatic changes in thermodynamic, folding, aggregation spectral properties and enzymatic activity.

So called absorption modifying excepients, investigated for the possibility of increasing intestinal drug absorption, can increase the gut permeability. Stress and infections also seem to cause perturbations in intestinal permeability.

Detecting such perturbations confirmed that the planets were real. Accurate masses of the two planets, as well as their inclinations, were calculated from how much the planets perturb each other.

387; sec. 9.4.3, p. 410. Historically, general perturbations were investigated first. The classical methods are known as variation of the elements, variation of parameters or variation of the constants of integration.

In the context of cold dark matter cosmological models, perturbations on all scales are imprinted on the universe at very early times, for example by quantum fluctuations during an inflationary era. Later, as radiation redshifts away, these become mass perturbations, and they start to grow linearly. Only long after that, starting with small mass scales and advancing over time to larger mass scales, do the perturbations actually collapse to form (for example) galaxies or clusters of galaxies, in so-called hierarchical structure formation (see Physical cosmology). Press and Schechter observed that the fraction of mass in collapsed objects more massive than some mass M is related to the fraction of volume samples in which the smoothed initial density fluctuations are above some density threshold.

Vacuum field perturbations are simulated by fluid field perturbations and the aerodynamic resistance of viscous drag exerted on the interior of the vehicle is compared to the Lorentz force exerted by the zero-point field (a Casimir-like force is exerted on the exterior by unbalanced zero-point radiation pressures). They find that the optimized negative energy required for an Alcubierre drive is where it is a saucer-shaped vehicle with toroidal electromagnetic fields. The EM fields distort the vacuum field perturbations surrounding the craft sufficiently to affect the permeability and permittivity of space. In 2014 NASA's Eagleworks Laboratories announced that they had successfully validated the use of a Quantum Vacuum Plasma Thruster which makes use of the Casimir effect for propulsion.

At higher altitudes, where air drag is less significant, orbital decay takes longer. Slight atmospheric drag, lunar perturbations, Earth's gravity perturbations, solar wind and solar radiation pressure can gradually bring debris down to lower altitudes (where it decays), but at very high altitudes this may take millennia.Kessler 1991, p. 268. Although high-altitude orbits are less commonly used than LEO and the onset of the problem is slower, the numbers progress toward the critical threshold more quickly.

As one of the most massive asteroids, Hygiea is used by the Minor Planet Center to calculate perturbations. Hygiea is in an unstable three-body mean motion resonance with Jupiter and Saturn. The computed Lyapunov time for this asteroid is 30,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations by the planets. It is the lowest numbered asteroid in such a resonance (the next lowest numbered being 70 Panopaea).

Three different tests were done, with patients eyes both open and closed. Results of the study found that there were major differences in group 1, the control group, and group 2, the treatment group. More patients of the treatment group than the control group were able to maintain a healthy stance during perturbations. As both groups were being treated for post stroke symptoms, it was thought that these perturbations would enhance their posture and motor movements naturally.

Advances in quantitative proteomics would clearly enable more in-depth analysis of cellular systems. Biological systems are subject to a variety of perturbations (cell cycle, cellular differentiation, carcinogenesis, environment (biophysical), etc.). Transcriptional and translational responses to these perturbations results in functional changes to the proteome implicated in response to the stimulus. Therefore, describing and quantifying proteome-wide changes in protein abundance is crucial towards understanding biological phenomenon more holistically, on the level of the entire system.

Starting with his 1941 PhD thesis, Wasow was one of the main contributors to developing a mathematical theory of the boundary layer problem and singular perturbations. The organizers of a symposium in his honor at the Mathematics Research Center at Madison write: Wasow was "a substantial contributor to the study of singular perturbations for over twenty years". His textbook "Asymptotic expansions for ordinary differential equations" was the first "authoritative treatment" OMalley, p. 365 of the subject.

On the more experimental side, metabolic flux analysis allows the empirical estimation of reaction rates by stable isotope labelling. Within the kinetic paradigm, kinetic modelling of metabolic networks can be purely theoretical, exploring the potential space of dynamic metabolic fluxes under perturbations away from steady state using formalisms such as biochemical systems theory. Such explorations are most informative when accompanied by empirical measurements of the system under study following actual perturbations, as is the case in metabolic control analysis.

In this state, the functional networks are in a low-firing stable state while they are continuously pulled towards multiple other configurations. Small extrinsic perturbations can shape task-related network dynamics, whereas perturbations from intrinsic noise generate excursions reflecting the range of available functional networks. This is particularly advantageous for the efficiency and speed of network mobilization. Thus, the resting state reflects the dynamical capabilities of the brain, which emphasizes the vital interplay of time and space.

Expression of genes associated with super-enhancers is particularly sensitive to perturbations, which may facilitate cell state transitions or explain sensitivity of super-enhancer—associated genes to small molecules that target transcription.

Simplified perturbations models are a set of five mathematical models (SGP, SGP4, SDP4, SGP8 and SDP8) used to calculate orbital state vectors of satellites and space debris relative to the Earth-centered inertial coordinate system. This set of models is often referred to collectively as SGP4 due to the frequency of use of that model particularly with two-line element sets produced by NORAD and NASA. These models predict the effect of perturbations caused by the Earth’s shape, drag, radiation, and gravitation effects from other bodies such as the sun and moon. Simplified General Perturbations (SGP) models apply to near earth objects with an orbital period of less than 225 minutes. Simplified Deep Space Perturbations (SDP) models apply to objects with an orbital period greater than 225 minutes, which corresponds to an altitude of 5,877.5 km, assuming a circular orbit. The SGP4 and SDP4 models were published along with sample code in FORTRAN IV in 1988 with refinements over the original model to handle the larger number of objects in orbit since.

Honey is sufficiently viscous that the surface perturbations that lead to breakup are almost fully damped from honey threads. This results in the production of long filaments of honey rather than individual droplets.

A neural network without residual parts explores more of the feature space. This makes it more vulnerable to perturbations that cause it to leave the manifold, and necessitates extra training data to recover.

He is the coauthor of two recent papers that brought back this field from a decade with no new data (with over 200 and 100 citations in the last five and four years, respectively). Hume was a coauthor of the best-cited article on cosmological perturbations (>3000 citations) developing a gauge invariant formalism that is widely considered to be the gold standard in this sub- discipline.V.F. Mukhanov, Hume A. Feldman & R. Brandenberger, Theory of Cosmological Perturbations. Phys. Rep. 215 206-328 (1992).

The process undergone by a fluid thread or jet undergoing breakup from a larger mass to a smaller mass. The breakup process in a fluid thread or jet begins with the development of small perturbations on the free surface of the fluid. This is known as the linear theory of fluid thread breakup. These perturbations are always present and can be generated by numerous sources including vibrations of the fluid container or non-uniformity in the shear stress on the free surface.

Chapel Hill: Professional Press. p. 143 Perturbations are said to be precisely encoded information contained in the thought field; each deformation of a person's thought field is connected to a particular problem, and is activated by thinking about that problem. Callahan maintains that these perturbations are the root cause of negative emotions and that each perturbation corresponds to a meridian point on the body. In order to eliminate the emotional upset, Callahan says that a precise sequence of meridian points must be tapped.

Above absolute zero, thermal motions will introduce random perturbations to the chromophores local environment. These perturbations shift the energy of the electronic transition, introducing a temperature dependent broadening of the line width. The measured width of a single chromophore’s zero phonon line, the homogeneous line width, is then γh(T) ≥ 1/T1 . The line shape of the phonon side band is that of a Poisson distribution as it expresses a discrete number of events, electronic transitions with phonons, during a period of time.

In astronomy, secular variations are contrasted with periodic phenomena. In particular, astronomical ephemerides use secular to label the longest-lasting or non-oscillatory perturbations in the motion of planets, as opposed to periodic perturbations which exhibit repetition over the course of a time frame of interest. In this context it is referred to as secular motion. Solar System ephemerides are essential for the navigation of spacecraft and for all kinds of space observations of the planets, their natural satellites, stars and galaxies.

This is the condition that fails to hold for non-Abelian gauge groups. If one ignores the problem and attempts to use the Feynman rules obtained from "naive" functional quantization, one finds that one's calculations contain unremovable anomalies. The problem of perturbative calculations in QCD was solved by introducing additional fields known as Faddeev–Popov ghosts, whose contribution to the gauge-fixed Lagrangian offsets the anomaly introduced by the coupling of "physical" and "unphysical" perturbations of the non-Abelian gauge field. From the functional quantization perspective, the "unphysical" perturbations of the field configuration (the gauge transformations) form a subspace of the space of all (infinitesimal) perturbations; in the non-Abelian case, the embedding of this subspace in the larger space depends on the configuration around which the perturbation takes place.

A human example of a preflex stabilization occurs when a person explosively jumps up from a squat position, and the leg muscles act to provide a minimal time delay against perturbations from the vertical.

The Comité International Spécial des Perturbations Radioélectriques (CISPR; ) was founded in 1934 to set standards for controlling electromagnetic interference in electrical and electronic devices, and is a part of the International Electrotechnical Commission (IEC).

The fluctuation–dissipation theorem is a general result of statistical thermodynamics that quantifies the relation between the fluctuations in a system that obeys detailed balance and the response of the system to applied perturbations.

The hypothetical motion that the body follows under the gravitational effect of one other body only is typically a conic section, and can be readily modeled with the methods of geometry. This is called a two-body problem, or an unperturbed Keplerian orbit. The differences between the Keplerian orbit and the actual motion of the body are caused by perturbations. These perturbations are caused by forces other than the gravitational effect between the primary and secondary body and must be modeled to create an accurate orbit simulation.

The Weibel instability is a plasma instability present in homogeneous or nearly homogeneous electromagnetic plasmas which possess an anisotropy in momentum (velocity) space. This anisotropy is most generally understood as two temperatures in different directions. Burton Fried showed that this instability can be understood more simply as the superposition of many counter-streaming beams. In this sense, it is like the two-stream instability except that the perturbations are electromagnetic and result in filamentation as opposed to electrostatic perturbations which would result in charge bunching.

Determining if an asteroid was an ECA required calculation of its orbits millennia into the future, including planetary gravitational perturbations, to assess whether a collision with Earth was possible and this has proved to be impractical.Brian G. Marsden, "Press Information Sheet:Potentially Hazardous Asteroids", Harvard-Smithsonian Center for Astrophysics, retrieved online 3 May 2009. Having a small MOID is not a guarantee of a collision. On the other hand, small gravitational perturbations of the asteroid around its orbit from planets that it passes can significantly alter its path.

As noted above, J.R. Partington points out that a state of thermodynamic equilibrium is stable against small transient perturbations. Without this condition, in general, experiments intended to study systems in thermodynamic equilibrium are in severe difficulties.

2014 . Instability in the boundary layer leads to perturbations that increase in size until a feedback path is established whereby specific frequencies of the resonance chamber are emphasized.Shadle, C. H. Experiments on the acoustics of whistling.

He retired from Woods Hole in 2007 as Scientist Emeritus. Hart is a leading pioneer in the introduction of geochemistry into the Earth sciences. He developed comparative geochronology, which accounts for geological perturbations in various geochronometers.

The analysis assumes that the flow is an incompressible flow, and that the perturbations are governed by the linearized Euler equations and, thus, are inviscid. With these considerations, the main result of this analysis is that, if the density of the burnt gases is less than that of the reactants, which is the case in practice due to the thermal expansion of the gas produced by the combustion process, the flame front is unstable to perturbations of any wavelength. Another result is that the rate of growth of the perturbations is inversely proportional to their wavelength; thus small flame wrinkles (but larger than the characteristic flame thickness) grow faster than larger ones. In practice, however, diffusive and buoyancy effects that are not taken into account by the analysis of Darrieus and Landau may have a stabilizing effect.

Pearse, J.S. 2006. Ecological role of purple sea urchins. Science 314: 940-941. The recovery of kelp forests from barren states has been documented following dramatic perturbations, such as urchin disease or large shifts in thermal conditions.

Singularly perturbed problems are generally characterized by dynamics operating on multiple scales. Several classes of singular perturbations are outlined below. The term "singular perturbation" was coined in the 1940s by Kurt Otto Friedrichs and Wolfgang R. Wasow.

Kerr–Schild perturbations are a special type of perturbation to a spacetime metric which only appear linearly in the Einstein field equations which describe general relativity. They were found by Roy Kerr and Alfred Schild in 1965.

To track satellites using Molniya orbits, scientists use the SDP4 simplified perturbations model, which calculates the location of a satellite based on orbital shape, drag, radiation, gravitation effects from the sun and moon, and earth resonance terms.

Clifford A. Pickover (1991) "Accident, Evolution, and Art". YLEN NEWSLETTER number. 12 volume 19 Nov/Dec. 1999. Pickover developed an algorithm (which uses neither random perturbations nor natural laws) to create very complicated forms resembling invertebrate organisms.

His mathematician and astronomical learning was noted. He became a Fellow of the Royal Society in 1796. Three years later (1799), he was awarded the Copley Medal largely for his paper on computing the perturbations of planets.

Comet C/1999 F1 has a similar period. Aphelion is estimated at 70,000 AU, but orbital periods of millions of years are very unstable as they are subject to perturbations by passing stars and the galactic tide.

Gennady Chibisov (; September 23, 1946 – August 7, 2008) was a Soviet/Russian cosmologist. He obtained his PhD in 1972, from the Moscow Institute of Physics and Technology, with a thesis entitled "Entropy perturbations in cosmology". He is best known for his 1981 paper on the origin of cosmological density perturbations from quantum fluctuations, coauthored with Viatcheslav Mukhanov. This is the earliest of a number of calculations addressing the origin of density fluctuations in inflationary cosmology, which is the most common hypothesis for the origin of the expanding universe and the structure within it.

See Having done so, he and others soon discovered over the course of a few years, those equations of motion did not predict some orbits correctly or even very well.Rudolf Kurth has an extensive discussion in his book (see References) on planetary perturbations. An aside: these mathematically undefined planetary perturbations (wobbles) still exist undefined even today and planetary orbits have to be constantly updated, usually yearly. See Astronomical Ephemeris and the American Ephemeris and Nautical Almanac, prepared jointly by the Nautical Almanac Offices of the United Kingdom and the United States of America.

Because the velocity is deduced from the vorticity in such theories, some authors describe the situation to imply that the vorticity is the cause of the velocity perturbations, using terms such as "the velocity induced by the vortex", for example.Anderson (1991), Section 5.2 But attributing mechanical cause-and-effect between the vorticity and the velocity in this way is not consistent with the physics.Batchelor (1967), Section 2.4Milne-Thomson (1966), Section 9.3Durand (1932), Section III.2 The velocity perturbations in the flow around a wing are in fact produced by the pressure field.

However, this is not to say that the Bohr-Sommerfeld model was without its successes. Calculations based on the Bohr–Sommerfeld model were able to accurately explain a number of more complex atomic spectral effects. For example, up to first-order perturbations, the Bohr model and quantum mechanics make the same predictions for the spectral line splitting in the Stark effect. At higher-order perturbations, however, the Bohr model and quantum mechanics differ, and measurements of the Stark effect under high field strengths helped confirm the correctness of quantum mechanics over the Bohr model.

Those that are in the center manifold are susceptible to small perturbations that generally push them about randomly, and often push them out of the center manifold. That is, small perturbations tend to destabilize points in the center manifold: the center manifold behaves like a saddle point, or rather, an extended collection of saddle points. There are dramatic counterexamples to this idea of instability at the center manifold; see Lagrangian coherent structure for detailed examples. A much more sophisticated example is the Anosov flow on tangent bundles of Riemann surfaces.

Perturbations by Jupiter send bodies straying there into unstable orbits. Most bodies formed within the radius of this gap were swept up by Mars (which has an aphelion at 1.67 AU) or ejected by its gravitational perturbations in the early history of the Solar System. The Hungaria asteroids lie closer to the Sun than the 4:1 resonance, but are protected from disruption by their high inclination. When the asteroid belt was first formed, the temperatures at a distance of 2.7 AU from the Sun formed a "snow line" below the freezing point of water.

During the 1880s the discrepancies between the best available lunar tables (published by Hansen in 1857) and observations had become so large that navigators could no longer use the moon's position to determine their longitude accurately. Nevill tackled the problem by first verifying Hansen's treatment of lunar perturbations caused by the direct action of the sun. He then devised an improved method for calculating perturbations caused by Venus. The remaining errors he ascribed to the gravitational pull of the other planets, whose effects were very difficult to calculate.

With a similar methodology, but using the term CRISP-seq instead of Perturb-seq, the paper "Dissecting Immune Circuits by Linking CRISPR-Pooled Screens with Single-Cell RNA-Seq" performed a proof of concept experiment by using the technique to probe regulatory pathways related to innate immunity in mice. Lethality of each perturbation and epistasis analyses in cells with multiple perturbations was also investigated in these papers. Perturb-seq has so far been used with very few perturbations per experiment, but it can theoretically be scaled up to address the whole genome.

213-227 In reality, however, small airflow velocity perturbations are caused by small vertical motions of the blades, resulting in variations in the induced wake field and airflow velocities. These airflow perturbations were not included in previous unsteady airflow models. In contrast, Isser's model added harmonic factors into the airflow model, taking into account the small periodic vertical motions of the blades during hovering or slow axial flight and treating the airflow differently in the near and far fields of the wake. To reduce the complexity of the model, Isser assumed mathematical simplifications.

SPT states are short-range entangled while topologically ordered states are long-range entangled. Both intrinsic topological order, and also SPT order, can sometimes have protected gapless boundary excitations. The difference is subtle: the gapless boundary excitations in intrinsic topological order can be robust against any local perturbations, while the gapless boundary excitations in SPT order are robust only against local perturbations that do not break the symmetry. So the gapless boundary excitations in intrinsic topological order are topologically protected, while the gapless boundary excitations in SPT order are symmetry protected.

Pasiphae group. Sinope orbits Jupiter on a high-eccentricity and high- inclination retrograde orbit. Its orbit is continuously changing due to solar and planetary perturbations. Sinope is believed to belong to the Pasiphae group of retrograde irregular moons.

Mirnov oscillations (a.k.a. magnetic oscillations) are amplitude perturbations of the magnetic field in a plasma. It is named after Sergei V. Mirnov who designed a probe to measure these oscillations in 1965. The probe name is Mirnov coil.

This allows for self-sustaining patterns of oscillation. Furthermore, new motor patterns, such as athletic skills or the ability to play an instrument, also use half-center oscillators and are simply learned perturbations to CPG's already in place.

However, it is not agreed upon among astronomers whether Arawn should be classified as a quasi-satellite of Pluto based on this motion, since its orbit is primarily controlled by Neptune with only occasional smaller perturbations caused by Pluto.

There are also alternatives to the static data masking that rely on stochastic perturbations of the data that preserve some of the statistical properties of the original data. Examples of statistical data obfuscation methods include differential privacy and the DataSifter method .

In quantum many-body physics, topological degeneracy is a phenomenon in which the ground state of a gapped many-body Hamiltonian becomes degenerate in the limit of large system size such that the degeneracy cannot be lifted by any local perturbations.

The mean eccentricity of an object is the average eccentricity as a result of perturbations over a given time period. Neptune currently has an instant (current epoch) eccentricity of 0.0113, but from 1800 to 2050 has a mean eccentricity of .

2D correlation analysis originated from 2D NMR spectroscopy. Isao Noda developed perturbation based 2D spectroscopy in the 1980s. This technique required sinusoidal perturbations to the chemical system under investigation. This specific type of the applied perturbation severely limited its possible applications.

Mean longitude is the ecliptic longitude at which an orbiting body could be found if its orbit were circular and free of perturbations. While nominally a simple longitude, in practice the mean longitude does not correspond to any one physical angle.

Analysis of flight data indicated a significant number of high-voltage breakdowns, and this apparently caused electromagnetic interference (EMI), causing attitude perturbations of the spacecraft. Ground tests indicated that the engine arcing produced conducted and radiated EMI significantly above design levels.

Naiad is irregularly shaped. It is likely that it is a rubble pile re-accreted from fragments of Neptune's original satellites, which were smashed up by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit.

It is still the Air Force Astrodynamic Standard for Uncorrelated Target (UCT) processing.Miller, James G.. Special Perturbations Uncorrelated Track Processing. AAS 07-228.(sic). Paper presented at the 2007 AAS/AIAA Astrodyamics Specialist Conference, Mackinac Island, Michigan, 19–23 August 2007.

Originating within of the star, this exozodiacal dust may be evidence of dynamical perturbations within the system. This may be caused by an intense bombardment of comets or meteors, and may be evidence for the existence of a planetary system.

Her peer-reviewed publications focus on the dissolved inorganic carbon cycling in groundwaters. She serves as a Principal Investigator on the National Science Foundation grant IRES: U.S - Cameroon Collaboration Investigating Anthropogenic Perturbations on Carbon Cycling in an Urbanized Tropical Estuary.

Most of the known perturbations to motion in stable, regular, and well- determined dynamical systems tend to be periodic at some level, but in many- body systems, chaotic dynamics result in some effects which are one-way (for example, planetary migration).

Generally, Rg2X molecules are less stable than RgX. is of double interest. It can cause perturbations in laser XeCl performance because it absorbs well at 308 nm and enables the development of another type of laser based on an emission.

Most of this research involves the treatment of sufficiently small but nevertheless fully non-linear perturbations of certain special backgrounds and includes an analysis of higher as well as lower-dimensional spacetimes in addition to physical (3 + 1)-dimensional spacetime.

Roy (1988): ch. 6, 7. Mercury's orbital longitude and latitude, as perturbed by Venus, Jupiter and all of the planets of the Solar System, at intervals of 2.5 days. Mercury would remain centered on the crosshairs if there were no perturbations.

Pressure and shock waves released by electric discharges are capable of perturbing the air in their vicinity up to 80%. This, however, has immediate consequences on the motion and properties of secondary streamer discharges in perturbed air: Depending on the direction (relative to the ambient electric field), air perturbations change the discharge velocities, facilitate branching or trigger the spontaneous initiation of a counter discharge. Recent simulations have shown that such perturbations are even capable to facilitate the production of X-rays (with energies of several tens of keV) from such streamer discharges, which are produced by run-away electrons through the Bremsstrahlung process.

Any orbiting spacecraft is sensitive to the local gravity field, plus the gravity field of the Sun and, to a minor extent, other planets. These gravitational perturbations generate spacecraft orbital velocity perturbations, from which the gravity field of a planet can be determined. EnVision's low-eccentricity, near-polar and relatively low altitude orbit offers the opportunity to obtain a high-resolution gravity field at each longitude and latitude of the Venusian globe. The analysis of the gravity field together with the topography gives insights on the lithospheric and crustal structure, allowing to better understand Venus's geological evolution.

This is similar to what happens when one examines sediment across the PETM, although the magnitude of the negative carbon isotope excursion is not as large. The timing of Earth system perturbations during ETM-2 and the PETM also appear different. Specifically, the onset of ETM-2 may have been longer (perhaps 30,000 years) while the recovery seems to have been shorter (perhaps <50,000 years). (Note, however, that the timing of short-term carbon cycle perturbations during both events remains difficult to constrain). A thin clay-rich horizon marks ETM-2 in marine sediment from widely separated locations.

The initial stage of the natural transition process is known as the Receptivity phase and consists of the transformation of environmental disturbances – both acoustic (sound) and vortical (turbulence) – into small perturbations within the boundary layer. The mechanisms by which these disturbances arise are varied and include freestream sound and/or turbulence interacting with surface curvature, shape discontinuities and surface roughness. These initial conditions are small, often unmeasurable perturbations to the basic state flow. From here, the growth (or decay) of these disturbances depends on the nature of the disturbance and the nature of the basic state.

There exists, however, an almost circular orbit for which there are no secular/long periodic perturbations of the eccentricity vector, only periodic perturbations with period equal to the orbital period. Such an orbit is then perfectly periodic (except for the orbital plane precession) and it is therefore called a "frozen orbit". Such an orbit is often the preferred choice for an Earth observation mission where repeated observations of the same area of the Earth should be made under as constant observation conditions as possible. The Earth observation satellites ERS-1, ERS-2 and Envisat are operated in sun-synchronous frozen orbits.

Advances in genomics and functional genomics have enabled large-scale analyses of gene and protein function by means of high-throughput cell biological analyses. Thereby, cells in culture can be perturbed in vitro and the induced effects recorded and analyzed. Perturbations can be triggered in several ways, for instance with molecules (siRNAs, expression constructs, small chemical compounds, ligands for receptors, etc.), through environmental stresses (such as temperature shift, serum starvation, oxygen deprivation, etc.), or combinations thereof. The cellular responses to such perturbations are analyzed in order to identify molecular events in the biological processes addressed and understand biological principles.

These halos would continue to grow in mass (and size), either through accretion of material from their immediate neighborhood, or by merging with other halos. Numerical simulations of CDM structure formation have been found to proceed as follows: A small volume with small perturbations initially expands with the expansion of the Universe. As time proceeds, small-scale perturbations grow and collapse to form small halos. At a later stage, these small halos merge to form a single virialized dark matter halo with an ellipsoidal shape, which reveals some substructure in the form of dark matter sub-halos.

In stability theory, the Briggs–Bers criterion is a criterion for determining whether the trivial solution to a linear partial differential equation with constant coefficients is stable, convectively unstable or absolutely unstable. This is often useful in applied mathematics, especially in fluid dynamics, because linear PDEs often govern small perturbations to a system, and we are interested in whether such perturbations grow or decay. The Briggs–Bers criterion is named after R. J. Briggs and A. Bers. Suppose that the PDE is of the form Ly=0, where y = y(x,t) is a function of space and time(x and t).

1, Cambridge, UK: Cambridge University Press, , 2004, pp. 263-280 The orbital elements are as of January 2000. They are continuously changing due to solar and planetary perturbations. The diagram illustrates its orbit in relation to other retrograde irregular satellites of Jupiter.

Shlomi, Tomer, Omer Berkman, and Eytan Ruppin. "Regulatory On/off Minimization of Metabolic Flux Changes After Genetic Perturbations." Proceedings of the National Academy of Sciences of the United States of America 102, no. 21 (May 24, 2005): 7695–7700. doi:10.1073/pnas.0406346102.

In chemistry, Bema Hapothle is an extended acronym for Bell–Marcus–Hammond–Polanyi–Thornton–Leffler, referring to the combined contribution of the theories of these chemists to the rationalization of changes in transition state structure to perturbations, such as change of reaction solvent.

The most important applications of semiclassical gravity are to understand the Hawking radiation of black holes and the generation of random gaussian-distributed perturbations in the theory of cosmic inflation, which is thought to occur at the very beginnings of the big bang.

Another procedure is to optimize a sub-part of the problem, having that keeps active the not-undo property. If this procedure is possible, all solutions generated after the perturbations tend to be very good. Furthermore the new parts are optimized too.

That study and additional evidence indicates that under stressful conditions or system perturbations, older individuals are less able to compensate due to the age- related reduction in reserve capacity (add Pendergast reference) and are more at risk to experience airway penetration or aspiration.

Consequently, any climatic perturbations produce slow responses, occurring over glacial and interglacial periods. Valley glaciers respond rapidly to climatic fluctuations with typical response times of 10–50 years.Oerlemans, J., 1994: Quantifying global warming from the retreat of glaciers. Science, 264, 243–245.

In the dielectric, the field will fall off far more slowly. SPPs are very sensitive to slight perturbations within the skin depth and because of this, SPPs are often used to probe inhomogeneities of a surface. For more details, see surface plasmon polariton.

P. cynomolgi closely resembles the human parasite P. vivax throughout its life cycle. Similar to P. vivax, P. cynomolgi infection changes the red blood cell membrane structure, causing surface perturbations that appear as pink dots (called Schüffner's dots) when stained with Giemsa.

During his work on the propagation of electron waves in a crystal lattice, he introduced the concept of Brillouin zones in 1930. Quantum mechanical perturbations techniques by Brillouin and by Eugene Wigner resulted in what is known as the Brillouin–Wigner formula.

Such external perturbations are the limiting factor for the achieved accuracies of atomic-shell based clocks. Due to this conceptual advantage, a nuclear optical clock is expected to achieve a time accuracy approaching 10−19, a ten-fold improvement over atomic-shell based clocks.

Spatial dispersion on the other hand represents spreading effects and is usually significant only at microscopic length scales. Spatial dispersion contributes relatively small perturbations to optics, giving weak effects such as optical activity. Spatial dispersion and temporal dispersion may occur in the same system.

Another approach for understanding Phosphorylation Network, is by measuring the genetic interactions between multiple phosphorylating proteins and their targets. This reveals interesting recurring patterns of interactions – network motifs. Computational methods have been developed to model phosphorylation networks and predict their responses under different perturbations.

Early in the 19th century, the methods of predicting the motions of the planets were somewhat scattered, having been developed over decades by many different researchers. In 1847, Le Verrier took on the task to "... embrace in a single work the entire planetary system, put everything in harmony if possible, otherwise, declare with certainty that there are as yet unknown causes of perturbations...", a work which would occupy him for the rest of his life. Le Verrier began by re-evaluating, to the 7th order, the technique of calculating the planetary perturbations known as the perturbing function. This derivation, which resulted in 469 mathematical terms, was complete by 1849.

The GEWEX modelling and prediction panel (GMPP) is charged with the task of finding better ways to use the data by other projects and other agencies. It oversees GEWEX Atmospheric Boundary Layer Study (GABLS), GEWEX Cloud System Study (GCSS), and Global Land/Atmosphere System Study(GLASS). Climate forcing is a process of study which observes the contribution of irregular events, such a volcano eruption, greenhouse warming, solar variation, fluctuations in the Earth's orbit, long-term variation in the oceans circulation. The GMPP exploits these natural perturbations to test models developed that should predict what happens to global energy and water budgets with the perturbations.

This would have allowed the detection of primordial gravitational waves in the universe so long as the ratio of scalar perturbations (caused by density fluctuations in the early universe) to the tensor perturbations caused by gravitational waves was greater than r = 0.01. It was hoped that the telescope would have spent around 2 years observing a total of around 1,000 degrees of sky, made up of several patches of sky where polarized foregrounds (synchrotron and thermal dust emission) are at a minimum. Clover was canceled in March 2009 as STFC were unable to provide the requested additional funds of 2.55 million pounds to finish the project.

However, an observed effect could also be caused "by chance", for example as a result of random perturbations in the population. Statistical tests exist to quantify the likelihood of erroneously concluding that an observed difference exists when in fact it does not (for example see P-value).

In some planetary systems, such as in the Upsilon Andromedae system, the eccentricity of orbits is maintained or even periodically varied by perturbations from other planets in the system. Tidal heating can cause outgassing from the mantle, contributing to the formation and replenishment of an atmosphere.

More biologically diverse communities appear to be more productive (in terms of biomass production) than are less diverse communities, and they appear to be more stable in the face of perturbations. Also animals that inhabit an area may alter the surviving conditions by factors assimilated by climate.

The two planets "exchange angular momentum in a 5:1 mean motion resonance". This planet was discovered on the vernal equinox of 2008 by analyzing perturbations with the inner planet HD 17156 b. The paper was submitted to Astrophysical Journal Letters 20 March and revised 14 June.

The impact of variation in regulatory regions is important for disease risk due their impact in the gene expression level. Furthermore, perturbations in the binding properties of proteins encoded by regulatory genes have been linked with phenotypes effects such as, duplicated structures, homeotic transformations and novel morphologies.

He was also the rector of Batory University in 1924–25. Later he moved to Nicolaus Copernicus University in Toruń. He spent the last part of his life in Toruń. He focused on the gravitational perturbations of minor planets, movements of stellar groupings, and photographic photometry.

Third, the collision frequency between electrons and background neutrals is assumed to be much less than the electron cyclotron frequency. Finally, we only analyze low frequency waves so that we can neglect electron inertia. Because the Buneman instability is electrostatic in nature, only electrostatic perturbations are considered.

Its population has seen extreme fluctuations in population size due to marine perturbations, which have become more extreme due to climate change. The population has ranged from as high as 10,000 specimens to as low as 700. Currently it is estimated there are about 1000 mature individuals.

The relation between diversity and stability has been widely studied. Diversity can operate to enhance the stability of ecosystem functions at various ecological scales. For example, genetic diversity can enhance resistance to environmental perturbations. At the community level, the structure of food webs can affect stability.

These disease-specific patterns of progression of atrophy can be identified with MRI scans, and provide a clinical phenotype context to neurogenomic research. The temporal information about disease progression provided by this approach can also potentially inform the interpretation of gene network-level perturbations in psychiatric diseases.

However, an observed effect could also be caused "by chance", for example as a result of random perturbations in the population. Statistical tests exist to quantify the likelihood of erroneously concluding that an observed difference exists when in fact it does not (for example see P-value).

Dietary sources involved in the construction of lipid raft, n-3 PUFA from oil fish as well as polyphenols, affect the molecular and structural shape of the phospholipids in the membrane. As such, this organisation model contributes to distinguishing effects of perturbations on cell membrane order and fluidity.

The other planets do not seem to be in any resonances, though near resonances are 3d:2e and 4e:3f. The planetary system in current configuration is highly susceptible to perturbations, therefore assuming stability, no additional giant planets can be located within 30 AU from the parent star.

Orbital perturbations cause longitude drift of the inoperable spacecraft and precession of the orbital plane. Close approaches (within 50 meters) are estimated at one per year."Colocation Strategy and Collision Avoidance for the Geostationary Satellites at 19 Degrees West." CNES Symposium on Space Dynamics, 6–10 November 1989.

Theor Ecol 3, 163–174Dakos, V., et al. (2008) Slowing down as an early warning signal for abrupt climate change. P Natl Acad Sci Usa 105, 14308–14312van Nes, E.H., and Scheffer, M. (2007) Slow recovery from perturbations as a generic indicator of a nearby catastrophic shift. Am. Nat.

Radau won the Prix Damoiseau of the French Academy of Sciences in 1892 working on planetary perturbations in the motion of the Moon. This work was of such a high quality that he was elected to the Academy in 1897. A crater on Mars is named in Radau's honor.

Some of the tsumi have to do with disease and natural disasters, and are not therefore sins in the modern sense, but order perturbations (kegare) which had to be dealt with and solved by the person or persons concerned in certain ways, for example through purification rites called harae.

Galatea is irregularly shaped and shows no sign of any geological modification. It is likely that it is a rubble pile re-accreted from fragments of Neptune's original satellites, which were smashed up by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit.

In condensed matter physics, relaxation is usually studied as a linear response to a small external perturbation. Since the underlying microscopic processes are active even in the absence of external perturbations, one can also study "relaxation in equilibrium" instead of the usual "relaxation into equilibrium" (see fluctuation-dissipation theorem).

Recent work has shown that multiple enhancers allow fruit flies to survive environmental perturbations, such as an increase in temperature. When raised at an elevated temperature, a single enhancer sometimes fails to drive the complete pattern of expression, whereas the presence of both enhancers permits normal gene expression.

In 2018 the Gaia project of the European Space Agency showed that Sgr dSph had caused perturbations in a set of stars near the Milky Way's core, causing unexpected rippling movements of the stars triggered when it moved past the Milky Way between 300 and 900 million years ago.

The canalisation metaphor suggests that some phenotypic traits are very robust to small perturbations, for which development does not exit the canal, and rapidly returns down, with little effect on the final outcome of development. But perturbations whose magnitude exceeds a certain threshold will break out of the canal, moving the developmental process into uncharted territory. For instance, the study of an allelic series for Fgf8, an important gene for craniofacial development, with decreasing levels of gene expression demonstrated that the phenotype remains canalised as long as the expression level is above 40% of the wild-type expression. Strong robustness up to a limit, with little robustness beyond, is a pattern that could increase evolvability in a fluctuating environment.

An osculating orbit and the object's position upon it can be fully described by the six standard Kepler orbital elements (osculating elements), which are easy to calculate as long as one knows the object's position and velocity relative to the central body. The osculating elements would remain constant in the absence of perturbations. Real astronomical orbits experience perturbations that cause the osculating elements to evolve, sometimes very quickly. In cases where general celestial mechanical analyses of the motion have been carried out (as they have been for the major planets, the Moon, and other planetary satellites), the orbit can be described by a set of mean elements with secular and periodic terms.

An example would be GaAs-AlAs, constructing it from a virtual crystal of Al0.5Ga0.5As, then introducing an interface. After this a perturbation is added to turn the crystal into pure GaAs, whilst on the other side, the perturbation transforms the crystal in pure AlAs. These perturbations are sufficiently small so that they can be handled by linear- response theory and the electrostatic potential lineup across the interface can then be obtained up to the first order from the charge density response to those localized perturbations. Linear response theory works well for semiconductors with similar potentials (such as GaAs-AlAs) as well as dissimilar potentials (such as GaAs-Ge), which was doubted at first.

Each ephemeris was produced by numerical integration of the equations of motion, starting from a set of initial conditions. Due to the precision of modern observational data, the analytical method of general perturbations could no longer be applied to a high enough accuracy to adequately reproduce the observations. The method of special perturbations was applied, using numerical integration to solve the n-body problem, in effect putting the entire Solar System into motion in the computer's memory, accounting for all relevant physical laws. The initial conditions were both constants such as planetary masses, from outside sources, and parameters such as initial positions and velocities, adjusted to produce output which was a "best fit" to a large set of observations.

The horizon problem of big bang cosmology says that, without inflation, perturbations were never in causal contact before they entered the horizon and thus the homogeneity and isotropy of, for example, the large scale galaxy distributions cannot be explained. This is because, in an ordinary Friedmann–Lemaître–Robertson–Walker cosmology, the Hubble radius increases more rapidly than space expands, so perturbations only enter the Hubble radius, and are not pushed out by the expansion. This paradox is resolved by cosmic inflation, which suggests that during a phase of rapid expansion in the early universe the Hubble radius was nearly constant. Thus, large scale isotropy is due to quantum fluctuations produced during cosmic inflation that are pushed outside the horizon.

They were located in positions where their period of revolution about the Sun was an integer fraction of Jupiter's orbital period. Kirkwood proposed that the gravitational perturbations of the planet led to the removal of asteroids from these orbits. When the mean orbital period of an asteroid is an integer fraction of the orbital period of Jupiter, a mean-motion resonance with the gas giant is created that is sufficient to perturb an asteroid to new orbital elements. Asteroids that become located in the gap orbits (either primordially because of the migration of Jupiter's orbit, or due to prior perturbations or collisions) are gradually nudged into different, random orbits with a larger or smaller semi-major axis.

Early studies have focused their attention on the connection between the enhancement (decrease) of tropical rainfall in regions such as the Northeast Brazil, the Western Sub-Saharan Africa etc. and perturbations in the tropical Atlantic sea surface temperatures (Moura and Shukla (1981), Nobre and Shukla (1996).) Such research efforts have concentrated on the role of the interhemispheric (meridional) SST mode as a dynamical driver of the tropical Atlantic overlying atmosphere, by analyzing perturbations of this coupled tropical ocean-atmosphere system while examining local as well as remote influences (i.e. the tropical -mid-latitude N. Atlantic connection (Tanimoto and Xie (1999), Tourre et al. (1999)), the tropical Pacific influence via El Nino/La Nina events (Enfield and Mayer (1997)).

Up to a high order of approximation, mutual gravitational perturbations between major or minor planets only cause periodic variations in their orbits, that is, parameters oscillate between maximum and minimum values. The tidal effect gives rise to a quadratic term in the equations, which leads to unbounded growth. In the mathematical theories of the planetary orbits that form the basis of ephemerides, quadratic and higher order secular terms do occur, but these are mostly Taylor expansions of very long time periodic terms. The reason that tidal effects are different is that unlike distant gravitational perturbations, friction is an essential part of tidal acceleration, and leads to permanent loss of energy from the dynamic system in the form of heat.

A variety of factors can lead to periastron precession such as general relativity, stellar quadrupole moments, mutual star–planet tidal deformations, and perturbations from other planets. : For Mercury, the perihelion precession rate due to general relativistic effects is 43″ (arcseconds) per century. By comparison, the precession due to perturbations from the other planets in the Solar System is 532″ per century, whereas the oblateness of the Sun (quadrupole moment) causes a negligible contribution of 0.025″ per century. From classical mechanics, if stars and planets are considered to be purely spherical masses, then they will obey a simple inverse-square law, relating force to distance and hence execute closed elliptical orbits according to Bertrand's theorem.

This crystal bistability was proved by calculations for LiCuO2 and NaCuO2 crystals, in which the Cu3+ ion has the electronic e2(d8) configuration (similar to the CuF3 molecule). Giant enhancement of observable properties in interaction with external perturbations. In a recent development it was shown that in inorganic crystals with PJTE centers, in which the local distortions are not ordered (before the phase transition to the cooperative phase), the effect of interaction with external perturbations contains an orientational contribution which enhances the observable properties by several orders of magnitude. This was demonstrated on the properties of crystals like paraelectric BaTiO3 in interaction with electric fields (in permittivity and electrostriction), or under a strain gradient (flexoelectricity).

One was found at Tewantin in 1945. The mines weighed and were buoyant, so needed to be moored with sinkers, up to below the surface. Every 5 minutes hour perturbations due to the tides known as perts had to be recorded. Daily and weekly tests were carried out on all equipment.

They are continuously changing due to solar and planetary perturbations. The diagram illustrates Ananke's orbit in relation to other retrograde irregular satellites of Jupiter. The eccentricity of selected orbits is represented by the yellow segments (extending from the pericentre to the apocentre). The outermost regular satellite Callisto is located for reference.

Solar radiation pressure is a source of orbital perturbations. It significantly affects the orbits and trajectories of small bodies including all spacecraft. Solar radiation pressure affects bodies throughout much of the Solar System. Small bodies are more affected than large ones because of their lower mass relative to their surface area.

Orbital perturbation: changes in Asbolus semi-major axis during the next 5500 years. After the encounter with Jupiter in 2700 years, the orbit becomes unpredictable. Centaurs have short dynamical lifetimes due to perturbations by the giant planets. Asbolus is estimated to have an orbital half-life of about 860 kiloannum.

Such storms are caused by the interaction between solar winds and the Earth's magnetic field. Resultant magnetic perturbations generate electric fields,See Faraday's law of electromagnetic induction. which could disrupt ground-based electrical power grids. While geomagnetic storms do not occur that often, when sufficiently strong they can cause considerable damage.

This approach of determining stability from second variation is used now widely. Perturbation methods became very successful despite that nonlinear nature of capillary interaction can limit their application. Other methods now include direct simulation. To that moment most methods for stability determination required calculation of equilibrium as a basis for perturbations.

Thalassa is irregularly shaped. It is likely that it is a rubble pile re-accreted from fragments of Neptune's original satellites, which were smashed up by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit. Unusually for irregular bodies, it appears to be roughly disk-shaped.

Despina's diameter is approximately .Despina is irregularly shaped and shows no sign of any geological modification. It is likely that it is a rubble pile re-accreted from fragments of Neptune's original satellites, which were disrupted by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit.

Scoliosis: Review of diagnosis and treatment; Joseph A Janicki, Benjamin Alman, 2007. Scoliosis is also classified according to the region(s) they affect. The vertebral column can be deformed at the thoracic level, at the lumbar level or at both. In the lumbar region, scoliosis induces perturbations to standing balance.

Monitoring the spatial and temporal variability of algal blooms from satellite, over large marine regions up to the scale of the global ocean, has been instrumental in characterizing variability of marine ecosystems and is a key tool for research into how marine ecosystems respond to climate change and anthropogenic perturbations.

For smaller bodies particularly, light and stellar wind can cause significant perturbations to the attitude and direction of motion of the body, and over time can be significant. Of the planetary bodies, the motion of asteroids is particularly affected over large periods when the asteroids are rotating relative to the Sun.

The innovation butterfly is a metaphor that describes how seemingly minor perturbations (disturbances or changes) to project plans in a system connecting markets, demand, product features, and a firm's capabilities can steer the project, or an entire portfolio of projects, down an irreversible path in terms of technology and market evolution.

In addition, detached objects have a time-averaged eccentricity greater than 0.2 The Sednoids are a further extreme sub-grouping of the detached objects with perihelia so distant that it is confirmed that their orbits cannot be explained by perturbations from the giant planets, nor by interaction with the galactic tides.

Elara observed by the Wide-field Infrared Survey Explorer (WISE) spacecraft in 2014 Elara belongs to the Himalia group, five moons orbiting between 11 and 13 gigametres from Jupiter at an inclination of about 27.5°. Its orbital elements are as of January 2000. They are continuously changing due to solar and planetary perturbations.

Not all clogs lead to shutdowns, though even minor intake perturbations can result in lost revenue. Some measures are available to prevent jellyfish-related interruptions. Power plants in Japan use bubble-curtain devices which produce air bubbles near intake valves which lift the jellyfish, reducing the number that are sucked into the pumps.

304, 1959-1962 and altering its circulation, resulting in significant ecological changes both locally and remotely.De Pol- Holz, R., O. Ulloa, L. Dezileau, J. Kaiser, F. Lamy and D. Hebbeln. 2006. Melting of the Patagonian Ice Sheet and deglacial perturbations of the nitrogen cycle in the eastern South Pacific. Geophysical Research Letters, vol.

The mechanical ellipticity of the earth (dynamical flattening, symbol J2) is determined to high precision by observation of satellite orbit perturbations. Its relationship with the geometric flattening is indirect. The relationship depends on the internal density distribution. The 1980 Geodetic Reference System (GRS 80) posited a semi-major axis and a flattening.

Figure 1. Tidal temperature and wind perturbations at 100 km altitude for September 2005 as a function of universal time. The animation is based upon observations from the SABER and TIDI instruments on board the TIMED satellite. It shows the superposition of the most important diurnal and semidiurnal tidal components (migrating + nonmigrating).

Informally speaking, an assessment is a perfect Bayesian equilibrium if its strategies are sensible given its beliefs and its beliefs are confirmed on the outcome path given by its strategies. The definition of sequential equilibrium further requires that there be arbitrarily small perturbations of beliefs and associated strategies with the same property.

Integrating the orbit until the comet is outside the perturbations of the planets generates a barycentric aphelion of ~5700 AU and an orbital period of roughly 150,000 years. It will not be 30 AU from the Sun until 2028. It is estimated to be approximately the same size as 67P/Churyumov–Gerasimenko.

In this variation, the basic parameter that defines the restrictiveness of the RCL during the construction phase is self-adjusted according to the quality of the solutions previously found. There are also techniques for search speed-up, such as cost perturbations, bias functions, memorization and learning, and local search on partially constructed solutions.

A topologically ordered state is a state with complicated non-local quantum entanglement. The non-locality means that the quantum entanglement in a topologically ordered state is distributed among many different particles. As a result, the pattern of quantum entanglements cannot be destroyed by local perturbations. This significantly reduces the effect of decoherence.

Examples of systems that can be solved with perturbations include systems with nonlinear contributions to the equations of motion, interactions between particles, terms of higher powers in the Hamiltonian/free energy. For physical problems involving interactions between particles, the terms of the perturbation series may be displayed (and manipulated) using Feynman diagrams.

Additionally, the structure (or topology) of signaling pathways has been demonstrated to play an important role in robustness to genetic perturbations. Self-enhanced degradation has long been an example of robustness in System biology. Similarly, robustness of dorsoventral patterning in many species emerges from the balanced shuttling-degradation mechanisms involved in BMP signaling.

If the base of a surface convection zone is sharp and the convective timescales slower than the pulsation timescales, the convective flows react too slowly perturbations that can build up into large, coherent pulsations. This mechanism is known as convective blocking and is believed to drive pulsations in the \gamma Doradus variables.

Concluded with a discussion by Klaus Hasselmann. The Benjamin–Feir instability can be described with the nonlinear Schrödinger equation, by inserting a Stokes wave with side bands. Subsequently, with a more refined analysis, it has been shown – theoretically and experimentally – that the Stokes wave and its side bands exhibit Fermi–Pasta–Ulam–Tsingou recurrence: a cyclic alternation between modulation and demodulation. In 1978 Longuet-Higgins, by means of numerical modelling of fully non-linear waves and modulations (propagating in the carrier wave direction), presented a detailed analysis of the region of instability in deep water: both for superharmonics (for perturbations at the spatial scales smaller than the wavelength 2\pi/k) and subharmonics (for perturbations at the spatial scales larger than 2\pi/k).

It is clear that comets coming in from the Oort cloud often have their orbits strongly influenced by the gravity of giant planets as a result of a close encounter. Jupiter is the source of the greatest perturbations, being more than twice as massive as all the other planets combined. These perturbations can deflect long-period comets into shorter orbital periods. Based on their orbital characteristics, short-period comets are thought to originate from the centaurs and the Kuiper belt/scattered disc —a disk of objects in the trans-Neptunian region—whereas the source of long- period comets is thought to be the far more distant spherical Oort cloud (after the Dutch astronomer Jan Hendrik Oort who hypothesized its existence).

A pulsar timing array uses millisecond pulsars to seek out perturbations due to GWs in measurements of the time of arrival of pulses to a telescope, in other words, to look for deviations in the clock ticks. To detect GWs, pulsar timing arrays search for a distinct pattern of correlation and anti-correlation between the time of arrival of pulses from several pulsars. Although pulsar pulses travel through space for hundreds or thousands of years to reach us, pulsar timing arrays are sensitive to perturbations in their travel time of much less than a millionth of a second. The principal source of GWs to which pulsar timing arrays are sensitive are super-massive black hole binaries, that form from the collision of galaxies.

In mathematics, stability theory addresses the stability of solutions of differential equations and of trajectories of dynamical systems under small perturbations of initial conditions. The heat equation, for example, is a stable partial differential equation because small perturbations of initial data lead to small variations in temperature at a later time as a result of the maximum principle. In partial differential equations one may measure the distances between functions using Lp norms or the sup norm, while in differential geometry one may measure the distance between spaces using the Gromov–Hausdorff distance. In dynamical systems, an orbit is called Lyapunov stable if the forward orbit of any point is in a small enough neighborhood or it stays in a small (but perhaps, larger) neighborhood.

The chief advantage of digital broadcasts is that they prevent a number of complaints common to traditional analog broadcasts. For television, this includes the elimination of problems such as snowy pictures, ghosting and other distortion. These occur because of the nature of analog transmission, which means that perturbations due to noise will be evident in the final output. Digital transmission overcomes this problem because digital signals are reduced to discrete values upon reception and hence small perturbations do not affect the final output. In a simplified example, if a binary message 1011 was transmitted with signal amplitudes [1.0 0.0 1.0 1.0] and received with signal amplitudes [0.9 0.2 1.1 0.9] it would still decode to the binary message 1011— a perfect reproduction of what was sent.

The curvaton is a hypothetical elementary particle which mediates a scalar field in early universe cosmology. It can generate fluctuations during inflation, but does not itself drive inflation, instead it generates curvature perturbations at late times after the inflaton field has decayed and the decay products have redshifted away, when the curvaton is the dominant component of the energy density. It is used to generate a flat spectrum of CMB perturbations in models of inflation where the potential is otherwise too steep or in alternatives to inflation like the pre-Big Bang scenario. The model was proposed almost simultaneously in 2001 by three independent groups: Kari Enqvist and Martin S. Sloth, David Wands and David H. Lyth, Takeo Moroi and Tomo Takahashi.

Dr. Brian von Herzen and the Discovery team join Professors David M Karl (University of Hawaii) and Ricardo M Letelier (Oregon State University) to test wave powered pumps in an effort to bring nutrients from the depths of the oceans to the surface. This nutrient enrichment of the open ocean's well-lit surface layers is needed to enhance photosynthesis and trigger large blooms of phytoplankton that could increase the role of vast oceanic regions in the sequestration of anthropogenic carbon dioxide. However, before producing large scale perturbations using these pumps, the scientific team from Hawaii and Oregon wants to better understand the risks and benefits of such large scale perturbations by looking at the effect that the deployment of a few pumps may have in the environment.

Small, cumulative perturbations can cause quantum states to decohere and introduce errors in the computation, but such small perturbations do not change the braids' topological properties. This is like the effort required to cut a string and reattach the ends to form a different braid, as opposed to a ball (representing an ordinary quantum particle in four-dimensional spacetime) bumping into a wall. Alexei Kitaev proposed topological quantum computation in 1997. While the elements of a topological quantum computer originate in a purely mathematical realm, experiments in fractional quantum Hall systems indicate these elements may be created in the real world using semiconductors made of gallium arsenide at a temperature of near absolute zero and subjected to strong magnetic fields.

In applied mathematics and dynamical system theory, Lyapunov vectors, named after Aleksandr Lyapunov, describe characteristic expanding and contracting directions of a dynamical system. They have been used in predictability analysis and as initial perturbations for ensemble forecasting in numerical weather prediction. In modern practice they are often replaced by bred vectors for this purpose.

Theia is thought to have orbited in the L4 or L5 configuration presented by the Earth–Sun system, where it would tend to remain. In that case, it would have grown, potentially to a size comparable to Mars. Gravitational perturbations by Venus could have eventually put it onto a collision course with the early Earth.

After taking into account perturbations due a close approach to Jupiter the next perihelion was calculated to be on 15 March 1957 but in that year it was never found. It was also not discovered on its next predicted appearance in 1964. The most likely explanation for the two failures was the comet's faintness.

In 2006, an international team of astronomers announced the presence of an extended tidal stream surrounding the galaxy that challenges this picture and suggests the gravitational perturbations induced by the stream progenitor may be the cause for the warp. The galaxy was discovered in 1788 by William Herschel. Supernova 1940A was in this galaxy.

Fluids 19, 041301 (2007). Hairpin vortices resemble the horseshoe vortex, which exists because of perturbations of small upward motion due to differences in upward flowing velocities depending on the distance from the wall. These form multiple packets of hairpin vortices, where hairpin packets of different sizes could generate new vortices to add to the packet.

Thus, special relativity "mixes" electricity and magnetism into a single, inseparable phenomenon called electromagnetism, analogous to how relativity "mixes" space and time into spacetime. All observations on electromagnetism apply to what might be considered to be primarily magnetism, e.g. perturbations in the magnetic field are necessarily accompanied by a nonzero electric field, and propagate at the speed of light.

In mathematics, the Seifert conjecture states that every nonsingular, continuous vector field on the 3-sphere has a closed orbit. It is named after Herbert Seifert. In a 1950 paper, Seifert asked if such a vector field exists, but did not phrase non-existence as a conjecture. He also established the conjecture for perturbations of the Hopf fibration.

One advantage of the simplicity of FBA over dynamic simulations is that they are far less computationally expensive, allowing the simulation of large numbers of perturbations to the network. A second advantage is that the reconstructed model can be substantially simpler by avoiding the need to consider enzyme rates and the effect of complex interactions on enzyme kinetics.

As in Julius Caesar, though, perturbations in the political sphere are echoed and even amplified by events in the material world. Among the most often depicted of the inversions of the natural order is sleep. Macbeth says: "Methought I heard a voice cry, 'Sleep no more. / Macbeth does murder sleep'", and this is figuratively mirrored in Lady Macbeth's sleepwalking.

Studies show that for comets with high orbital inclinations and perihelion distances of less than about 2 astronomical units, the cumulative effect of gravitational perturbations over many orbits is adequate to reduce the perihelion distance to very small values. One study has suggested that Comet Hale–Bopp has about a 15% chance of eventually becoming a sungrazer.

This is because derivative action is more sensitive to higher- frequency terms in the inputs. Without derivative action, a PI-controlled system is less responsive to real (non-noise) and relatively fast alterations in state and so the system will be slower to reach setpoint and slower to respond to perturbations than a well-tuned PID system may be.

The algorithm is then defined as backward stable. Stability is a measure of the sensitivity to rounding errors of a given numerical procedure; by contrast, the condition number of a function for a given problem indicates the inherent sensitivity of the function to small perturbations in its input and is independent of the implementation used to solve the problem.

Others were destined to the child analysis or the failures of the symbolic capacity in psychosomatic perturbations. In the honour to his mentor, David Maldavsky designated as David Liberman algorithm the research method he created, useful for the study of wishes and defenses in the verbal and non-verbal manifestations, either in clinic or in social terrain.

246P/NEAT is a periodic comet discovered on 2004 March 28 by Near-Earth Asteroid Tracking (NEAT) using the reflector at Haleakala. It was given the permanent number 246P on 2011 January 14. It is a Quasi-Hilda comet. Due to perturbations by Jupiter, the 2005, 2013 and 2021 perihelion passages will be closer to the Sun.

Real material systems always incorporate disorder. Examples are structural defects in the lattice or disorder due to variations of the chemical composition. Their treatment is extremely challenging for microscopic theories due to the lack of detailed knowledge about perturbations of the ideal structure. Thus, the influence of the extrinsic effects on the PL is usually addressed phenomenologically.

Slowing of the accretion is caused by gravitational perturbations by large bodies on the remaining planetesimals. In addition, the influence of larger bodies stops further growth of smaller bodies. The next stage is called oligarchic accretion. It is characterized by the dominance of several hundred of the largest bodies—oligarchs, which continue to slowly accrete planetesimals.

In practice, however, variations in the refractive index of the interstellar and intergalactic media and Earth's atmosphere are small enough that the theorem is approximately true to within any reasonable experimental error. Such variations in the refractive index of the medium result only in slight perturbations from the case of a wavefront traveling through a homogeneous medium.

Large neutron poison loads in these facilities are of no particular concern with respect to fuel element power distribution perturbations or effects on fuel cycle length because of their distance from the core; however, experiments are carefully reviewed with respect to their neutron poison content, which is limited to minimize their effect on adjacent neutron scattering beam tubes.

HD 38529 B is a common proper motion stellar companion to HD 38529 A at a projected distance of about ~12000 Astronomical units. The star is a red dwarf of spectral type M3.0V. Wide binary stars such as HD 38529 AB have been shown to be vulnerable to disruption by galactic tides and perturbations by passing stars.

The ratio of axes of Cressida's prolate spheroid is 0.8 ± 0.3. Its surface is grey in color. Cressida orbits close to a 3:2 resonance with the η ring, one of the rings of Uranus. Perturbations of the ring's shape provide a way to measure the mass of Cressida, which was found to be 2.5±0.4 kg.

Duffy is the author of over 100 scientific publications and the founding editor of the journal Waterbirds. Additionally, he was editor of Colonial Waterbirds from 1997-2000. His research has involved how species, ecosystems, and landscapes recover from perturbations, both man- made and natural. He was a featured scientist on National Geographic's "Strange Days on Planet Earth".

Configurations of a charged scalar field that are classically stable (stable against small perturbations) were constructed by Rosen in 1968. Stable configurations of multiple scalar fields were studied by Friedberg, Lee, and Sirlin in 1976. The name "Q-ball" and the proof of quantum-mechanical stability (stability against tunnelling to lower energy configurations) come from Sidney Coleman.

The viscosity of honey is large enough to damp all surface perturbations that would lead to the breakup of the thread into droplets. Numerous examples of the breakup of fluid threads exist in daily life. It is one of the most common fluid mechanics phenomena one experiences and as such most give the process little thought.

3 for an example. Electronic equipment and signal and power transmission lines can be subjected to voltage surges induced by lightning, electrostatic discharge, radio frequency transmissions, switching pulses (spikes) and perturbations in power supply.Hasse, p. 43. Remote lightning strikes can induce surges up to 10 kV, one thousand times more than the voltage limits of many electronic components.

The Zodiacal Light Observatory currently consists of two instruments. The Scatter-free Observatory for Limb Active Regions and Coronae (SOLARC or SOLAR-C) telescope is a off-axis reflecting coronagraph that is used to study the Sun's corona. The Day-Night Seeing Monitor Telescope System (DNSM) makes telescope-independent observations of perturbations in the atmosphere above Haleakala.

A deep-sea chimaera. Its snout is covered with tiny pores capable of detecting animals by perturbations in electric fields. The deepest recorded oceanic trench measured to date is the Mariana Trench, near the Philippines, in the Pacific Ocean at . At such depths, water pressure is extreme and there is no sunlight, but some life still exists.

The topology of an interactome makes certain predictions how a network reacts to the perturbation (e.g. removal) of nodes (proteins) or edges (interactions). Such perturbations can be caused by mutations of genes, and thus their proteins, and a network reaction can manifest as a disease. A network analysis can identify drug targets and biomarkers of diseases.

Quantum gravity effects are notoriously difficult to measure because the Planck length is so incredibly small. However recently physicists have started to consider the possibility of measuring quantum gravity effects mostly from astrophysical observations and gravitational wave detectors. The energy of those fluctuations at scales this small cause space-perturbations which are visible at higher scales.

Studies using mice lacking functional PPAR-alpha indicate that PPAR-alpha is essential for induction of peroxisome proliferation by a diverse set of synthetic compounds referred to as peroxisome proliferators. Mice lacking PPAR-alpha also have an impaired response to fasting, characterized by major metabolic perturbations including low plasma levels of ketone bodies, hypoglycemia, and fatty liver.

Her research included working in the Duke Forest on "Assessing the Effects of Elevated Atmospheric CO2 and LAI Perturbations on Southeastern Grassland Water Vapor and CO2 Fluxes." In pursuit to obtain her Ph.D, Novick went back to Duke University and graduated in 2010 and continued her research at the Duke Forest to study forest carbon and water cycling.

However, because the signal depends on the uniformity of the perturbation, the extraction of such parameters must be treated with care.S. Koeppen and P. Handler,"Field Inhomogeneity in Electroreflectance," Phys. Rev. 187, 1182-1185 (1969). doi:10.1103/PhysRev.187.1182D.E. Aspnes and A. Frova, "Influence of Spatially Dependent Perturbations on Modulated Reflectance and Absorption of Solids," Solid State Comm.

Nikolay Bogoliubov considered perturbations on the limit of dilute gas, finding a finite pressure at zero temperature and positive chemical potential. This leads to corrections for the ground state. The Bogoliubov state has pressure (T = 0): P = gn^2/2. The original interacting system can be converted to a system of non-interacting particles with a dispersion law.

It may have also resulted from the Kozai mechanism, driven by perturbations either from the Sun's tidal forces, or from higher order terms in the gravitational potential of Gonggong due to its oblate shape. The orbital dynamics are thought to be similar to that of Quaoar's satellite Weywot, which has a moderate eccentricity of about 0.14.

Lunar mascons alter the local gravity above and around them sufficiently that low and uncorrected satellite orbits around the Moon are unstable on a timescale of months or years. The small perturbations in the orbits accumulate and eventually distort the orbit enough that the satellite impacts the surface. The Luna-10 orbiter was the first artificial object to orbit the Moon and it returned tracking data indicating that the lunar gravitational field caused larger than expected perturbations presumably due to 'roughness' of the lunar gravitational field. The Lunar mascons were discovered by Paul M. Muller and William L. Sjogren of the NASA Jet Propulsion Laboratory (JPL) in 1968 from a new analytic method applied to the highly precise navigation data from the unmanned pre-Apollo Lunar Orbiter spacecraft.

Where one body is much more massive than the other (as is the case of an artificial satellite orbiting a planet), it is a convenient approximation to take the center of mass as coinciding with the center of the more massive body. Advances in Newtonian mechanics were then used to explore variations from the simple assumptions behind Kepler orbits, such as the perturbations due to other bodies, or the impact of spheroidal rather than spherical bodies. Lagrange (1736–1813) developed a new approach to Newtonian mechanics emphasizing energy more than force, and made progress on the three body problem, discovering the Lagrangian points. In a dramatic vindication of classical mechanics, in 1846 Urbain Le Verrier was able to predict the position of Neptune based on unexplained perturbations in the orbit of Uranus.

There is a 'chicken and egg' question: are the perturbations seen in atmospheric CO2 concentrations forced by the vigour of the deep ocean currents, or vice versa? McCave uses monitoring points in the North Atlantic Ocean, Pacific Ocean and Indian Ocean to study how the Earth’s meridional heat flux is distributed by warm surface-ocean currents and cold deep-ocean currents.

In this instability region, solar perturbations at apoapse cause the moons in this region to acquire large eccentricities that lead to collisions or ejection over 10 million to a billion years. Margaret's periapsis precession period (Pw) is almost 1.6 million years long. Margaret itself may be ejected from the Uranian system in the far future. In 2010, Margaret's orbital eccentricity was 0.812.

Smyth chose to name it after Hestia, Greek goddess of the hearth. This created a problem in Greek, where 4 Vesta also goes by the name Hestia. The computed Lyapunov time for this asteroid is 30,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets. Hestia has been studied by radar.

It is well known that the space of distributions has no product structure. This is the core problem of such theory. This leads to the need of some form of renormalization. An early attempt to circumvent such problems for some specific equations was the so called da Pratto-Debusche trick which involved studying such non-linear equations as perturbations of linear ones.

Local perturbations: Features should be insensitive to classes of semi-local image disturbances. For example, a feature responding to the eye of a human face should be unaffected by any motion of the mouth. A second class of disturbance is where a region neighbours a foreground/background boundary. The detector can be required to detect the foreground region despite changes in the background.

In mathematics, an analytic semigroup is particular kind of strongly continuous semigroup. Analytic semigroups are used in the solution of partial differential equations; compared to strongly continuous semigroups, analytic semigroups provide better regularity of solutions to initial value problems, better results concerning perturbations of the infinitesimal generator, and a relationship between the type of the semigroup and the spectrum of the infinitesimal generator.

This suggests that the asteroid underwent differentiation by melting, creating a surface of basalt rock. The mass of Thetis has been calculated from perturbations by 4 Vesta and 11 Parthenope. In 2007, Baer and Chesley calculated Thetis to have a mass of 1.2 kg with a density of 3.21 g/cm³. One Thetidian stellar occultation was observed from Oregon in 1999.

Children manage adversity better when they have positive relationships with responsible adults, are good problem solvers, and are engaging and have characteristics that are valued by themselves and others. Masten and colleagues observed that long-term problems in contexts of adversity were often associated with neurobiological damage and with severe perturbations to the normal relationships of children with their caregivers.

Kahniashvili completed a B.S. in physics with high honors and a specialization in theoretical physics at the Tbilisi State University (TSU) in 1983. In 1984, she completed an M.S. in physics education and theoretical physics. Her thesis, Gauge Invariant Theory of Gravitational Perturbations, was supervised by V. N. Lukash. In 1988, Kahniashvili completed a Ph.D. in physics at the Russian Space Research Institute.

Current work on this model centers on whether it can succeed in stabilizing the size of the compactified dimensions and produce the correct spectrum of primordial density perturbations. Supporters admit that their model "does not solve the entropy and flatness problems of standard cosmology ..... and we can provide no explanation for why the current universe is so close to being spatially flat".

It has an observation arc of 32 days and an orbital uncertainty of 7. Since the asteroid has a poorly known orbit, the cone of uncertainty quickly multiplies as a result of perturbations by the inner planets and prevents precise/reliable ephemeris data. Eliminating an entry on the Sentry Risk Table is a negative prediction; a prediction of where it will NOT be.

Cenozoic mass extinctions in the deep sea; what disturbs the largest habitat on Earth? S. Monechi, R. Coccioni, and M. Rampino, eds., "Large Ecosystem Perturbations: Causes and Consequences", Geological Society of America Special Paper, 424: 1–24. General hypotheses such as a temperature-related reduction in oxygen availability, or increased corrosion due to carbonate undersaturated deep waters, are insufficient as explanations.

DE405 was released in 1998. It added several years' extra data from telescopic, radar, spacecraft, and VLBI observations (of the Galileo spacecraft at Jupiter, in particular). The method of modeling the asteroids' perturbations was improved, although the same number of asteroids were modeled. The ephemeris was more accurately oriented onto the ICRF. DE405 covered 1600 to 2200 to full precision.

He published another in 1927. His catalogs were in turn incorporated into later catalogs of all known double stars. He also published some papers on perturbations in Mars' and Venus' orbits. Despite having had no formal training in astronomy, he was invited to the Royal Observatory, Cape of Good Hope by the HM Astronomer Sir David Gill in 1894 and appointed in 1896.

Control equations can also be derived by considering the effect of perturbations on the system. Consider that reaction rates v_1 and v_2 are determined by two enzymes e_1 and e_2 respectively. Changing either enzyme will result in a change to the steady state level of x and the steady state reaction rates v. Consider a small change in e_1 of magnitude \delta e_1.

Predicting the overall orbit and position of Asbolus beyond a few thousand years is difficult because of errors in the known trajectory, error amplification by perturbations due to all of the gas giants, and the possibility of perturbation as a result of cometary outgassing and fragmentation. Compared to centaur 7066 Nessus, the orbit of Asbolus is currently much more chaotic.

CLASS is a new Boltzmann code developed in this line. The purpose of CLASS is to simulate the evolution of linear perturbations in the universe and to compute CMB and large scale structure observables. Its name also comes from the fact that it is written in object- oriented style mimicking the notion of class. Classes are a programming feature available, e.g.

This is known as the Law of Symmetry. The role of symmetry in grouping and figure/ground organization has been confirmed in many studies. For instance, detection of reflectional symmetry is faster when this is a property of a single object. Studies of human perception and psychophysics have shown that detection of symmetry is fast, efficient and robust to perturbations.

He and his colleagues (Edward Ott and Celso Grebogi) had shown with a numerical example that one can convert a chaotic motion into a periodic one by a proper time- dependent perturbations of the parameter. This article is considered as one among the classic works in the control theory of chaos and their control method is known as the O.G.Y. method.

Furthermore, asymptotic safety provides the possibility of inflation without the need of an inflaton field (while driven by the cosmological constant). It was reasoned that the scale invariance related to the non-Gaussian fixed point underlying asymptotic safety is responsible for the near scale invariance of the primordial density perturbations. Using different methods, asymptotically safe inflation was analyzed further by Weinberg.

Finally, in 2014 Imbrie presented a proof of MBL for certain one dimensional spin chains with strong disorder, with the localization being stable to arbitrary local perturbations – i.e. the systems were shown to be in a many body localized phase. It is now believed that MBL can arise also in periodically driven "Floquet" systems where energy is conserved only modulo the drive frequency.

In celestial mechanics, he found improved methods to deduce a planetary orbit from observations, and analysed the mathematics of perturbations in planetary motions. In particular, he made a more accurate determination of Neptune's orbit. He also found an improved method of determining the orbits of binary stars. His important papers were published in 1859 in the book Recherches astronomiques de l'observatoire de Kasan.

The resonance crossing excites the eccentricities of Jupiter and Saturn. The increased eccentricities create perturbations on Uranus and Neptune, increasing their eccentricities until the system becomes chaotic and orbits begin to intersect. Gravitational encounters between the planets then scatter Uranus and Neptune outward into the planetesimal disk. The disk is disrupted, scattering many of the planetesimals onto planet-crossing orbits.

The term secular function has been used for what is now called characteristic polynomial (in some literature the term secular function is still used). The term comes from the fact that the characteristic polynomial was used to calculate secular perturbations (on a time scale of a century, i.e. slow compared to annual motion) of planetary orbits, according to Lagrange's theory of oscillations.

Richard P.A.C. Newman (1955–2000) was a physicist notable for his work in the area of cosmology and general relativity. He completed his PhD in 1979 at the University of Kent at Canterbury under G.C. McVittie with a thesis entitled Singular Perturbations of the Empty Robertson-Walker Cosmologies. He was a research fellow at the University of York 1984-1986. He died 2000.

Finally, the work of Walter Heiligenberg expanded it into a full neuroethology study by examining the series of neural connections that led to the behavior.Heiligenberg, Walter (1991) Neural Nets in Electric Fish Cambridge: MIT Press. . Eigenmannia is a weakly electric fish that can self-generate electric discharges through electrocytes in its tail. Furthermore, it has the ability to electrolocate by analyzing the perturbations in its electric field.

Other types of TLEs include sprite halos, ghosts, blue jets, gigantic jets, pixies, gnomes, trolls, blue starters, and ELVESs. The acronym ELVES (“Emission of Light and Very Low Frequency perturbations due to Electromagnetic Pulse Sources”) refers to a singular event which is commonly thought of as being plural. TLEs are secondary phenomena that occur in the upper atmosphere in association with underlying thunderstorm lightning.

The synthesized substance was a particular metallofullerene consisting of 84 carbon atoms with two additional carbon atoms and two yttrium atoms inside the cage. The process produced approximately 100 micrograms. However, they found that the asymmetrical molecule could theoretically collapse to form nearly every known fullerene and metallofullerene. Minor perturbations involving the breaking of a few molecular bonds cause the cage to become highly symmetrical and stable.

Atalante was observed by Arecibo radar in October 2010. This asteroid shares a mean-motion resonance with the planets Jupiter and Saturn. The computed Lyapunov time for this asteroid is only 4,000 years, indicating that it occupies a highly chaotic orbit that will change randomly over time because of gravitational perturbations of the planets. This is the shortest Lyapunov time of the first 100 named asteroids.

This theorem is known as Ivory's theorem. He also published anonymously an edition of Euclid's Elements, which was described as having brought the difficult problems "more within the reach of ordinary understandings.""Ivory, James" Biographical dictionary of eminent Scotsmen Volume 2, Glasgow : Blackie & Son, 1875. Page 351 His later papers in the Philosophical Transactions treat of astronomical refractions, of planetary perturbations, of equilibrium of fluid masses, etc.

Free Ocean CO2 Enrichment (FOCE) is a technology facilitating studies of the consequences of ocean acidification for marine organisms and communities by enabling the precise control of CO2 enrichment within in situ, partially open, experimental enclosures. Current FOCE systems control experimental CO2 perturbations by real-time monitoring of differences in seawater pH between treatment (i.e. high-CO2) and control (i.e. ambient) seawater within experimental enclosures.

Am. Nat. 169, 738–747van Nes, E., and Scheffer, M. (2005) Implications of spatial heterogeneity for catastrophic regime shifts in ecosystems. Ecology 86, 1797–1807Hastings, A., and Wysham, D.B. (2010) Regime shifts in ecological systems can occur with no warning. Ecol Lett, 1–9 Systems approaching a bifurcation point show a characteristic behaviour called critical slowing down leading to an increasingly slow recovery from perturbations.

As the Reynolds number increases, smaller and smaller scales of the flow are visible. In a smoke stack, the smoke may appear to have many very small velocity perturbations or eddies, in addition to large bulky eddies. In this sense, the Reynolds number is an indicator of the range of scales in the flow. The higher the Reynolds number, the greater the range of scales.

Human and animal studies have suggested that perturbations in neurovascular integrity and breakdown of the BBB lead to neuronal hypersynchronization and epileptiform activity. Relevant molecular changes in brain tumors that affect BBB structure and function include decreased expression of transmembrane junctional proteins and heightened release of vascular endothelial growth factor. Results suggest that pathological disruption of the BBB in brain tumor patients may contribute to seizure activity.

They came from backgrounds in agriculture and climate. According to the Idsos, they became involved in the global warming controversy through their study of earth's temperature sensitivity to radiative perturbations and plant responses to elevated CO2 levels and carbon sequestration. The Center sharply disputes the scientific consensus on climate change shown in IPCC assessment reports, and believes that global warming will be beneficial to mankind.

Other biological factors influence how drugs are transported throughout the body and how they target specific locations for action. Some of these pathophysiological factors include blood flow alterations, edema and increased intracranial pressure, metabolic perturbations, and altered gene expression and protein synthesis. Though there exist many obstacles that make developing a robust delivery system difficult, nanoparticles provide a promising mechanism for drug transport to the CNS.

In general, the oblateness of the Earth perturbs the argument of perigee (\omega), so that even if the apogee started near the north pole, it would gradually move unless constantly corrected with station- keeping thruster burns. Keeping the dwell point over Russia, and useful for communications necessitated without excessive fuel use meant that the satellites needed an inclination of 63.4°, for which these perturbations are zero.

The morphological classification of SBc indicates a barred spiral with moderately-wound arms. The physical properties of this galaxy are similar to those of the Milky Way. The combined mass of stars in the galaxy is estimated at , and it has a star formation rate of y−1. There are no apparent perturbations of the galaxy due to suspected interaction with the companion galaxy, NGC 2770B.

Cellular proteostasis is key to ensuring successful development, healthy aging, resistance to environmental stresses, and to minimize homeostatic perturbations from pathogens such as viruses. Cellular mechanisms for maintaining proteostasis include regulated protein translation, chaperone assisted protein folding, and protein degradation pathways. Adjusting each of these mechanisms based the need for specific proteins is essential to maintain all cellular functions relying on a correctly folded proteome.

The perigee is similar to the cruising altitude of most modern airliners, and within Earth's atmosphere. Petit published another paper on his 1846 observations in 1861, basing the second moon's existence on perturbations in movements of the actual Moon. This second moon hypothesis was not confirmed either. Petit's proposed moon became a plot point in Jules Verne's 1870 science fiction novel Around the Moon.

They can be trained with standard backpropagation. CNNs are easier to train than other regular, deep, feed-forward neural networks and have many fewer parameters to estimate. Capsule Neural Networks (CapsNet) add structures called capsules to a CNN and reuse output from several capsules to form more stable (with respect to various perturbations) representations. Examples of applications in computer vision include DeepDream and robot navigation.

The leading area of a squall line is composed primarily of multiple updrafts, or singular regions of an updraft, rising from ground level to the highest extensions of the troposphere, condensing water and building a dark, ominous cloud to one with a noticeable overshooting top and anvil (thanks to synoptic scale winds). Because of the chaotic nature of updrafts and downdrafts, pressure perturbations are important.

A growing set of behavioral evidence supports this hypothesis. When subjective awareness of a visual stimulus is absent, people can still direct attention to that stimulus, but that attention loses some aspects of control. It is less stable over time, and is less adaptable given training on perturbations. These findings support the proposal that awareness acts like the internal model for the control of attention.

The renormalization group provides an intuitively appealing, albeit mathematically non-rigorous, explanation of universality. It classifies operators in a statistical field theory into relevant and irrelevant. Relevant operators are those responsible for perturbations to the free energy, the imaginary time Lagrangian, that will affect the continuum limit, and can be seen at long distances. Irrelevant operators are those that only change the short-distance details.

A common model for studying motor learning and consolidation involves perturbations to reaching tasks using robotic arms to impart forces on the limb during reaches, forcing the subject to learn new internal representations of the limb to take these new external forces into account.Ahmed AA, Wolpert DM, Flanagan JR. Flexible representations of dynamics are used in object manipulation. Curr Biol. 2008 May 20;18(10):763-8.

This occurs when the first derivative of the energy with respect to the magnetization direction is zero: This direction is stable against perturbations when it is at an energy minimum, having a positive second derivative: In zero field the magnetic anisotropy term is minimized when the magnetization is aligned with the easy axis. In a large field, the magnetization is pointed towards the field.

The cantilever can be called as SPM acoustic antenna which senses the interference of acoustic waves sent by the transducers. The interference of these waves forms surface acoustic standing waves. The wave's frequencies are slightly different. The perturbations to phase and amplitude of the surface acoustic standing wave are locally monitored by the antenna via the lock-in approach and the SPM electronic module.

Neel V. Patel, MIT Technology Review. 2 October 2019. Quote: surface conditions are dependent on a host of different individual properties of that planet, such as internal and geological processes, magnetic field evolution, climate, atmospheric escape, rotational effects, tidal forces, orbits, star formation and evolution, unusual conditions like binary star systems, and gravitational perturbations from passing bodies. This misunderstanding is reflected in excited reports of 'habitable planets'.

If cosmic expansion were to halt and reverse due to gravity, the temperature of the Universe would once again grow hotter, but its entropy would also continue to increase due to the continued growth of perturbations and the eventual black hole formation,Penrose, R. The Road to Reality pp. 686-734 until the latter stages of the Big Crunch when entropy would be lower than now.

The major threats of the frecklebelly darter include decimation through perturbations such as strip mining as well as stream channelization projects. The darter is thought to have a high resilience with minimum population doubling time less than 15 months; it is also believed to have low vulnerability. Frecklebelly darter females contain about 100-300 mature ova depending on size. Fish become mature by age 1.

Don Quixote is characterized as a dark D-type asteroid in the Tholen and SMASS taxonomy. It has a highly inclined comet-like orbit of 31 degrees that leads to frequent perturbations by Jupiter. Don Quixote measures 18.4 kilometres in diameter and has a rotation period of 7.7 hours. Due to its comet-like orbit and albedo, Don Quixote has been suspected to be an extinct comet.

Retrieved 27 April 2014 . According to Dean F. Bajorin of the Sloan Kettering Cancer Center: > He was the first investigator to identify genetically distinct pathways for > superficial and muscle-invasive bladder cancers. The underpinnings for these > pathways were based on over a decade of studies elucidating genetic > perturbations seen in low and high-grade tumors. These pathways now serve as > a template for modern studies.

Pakistan Journal of Scientific and Industrial Research. Vol. 27, No. 4, pp.199-205. The pollutants along with other environmental perturbations have also proved to be harmful to the biodiversity of marine species along Karachi Fish HarbourS Saifullah and M Moazzam (1978) Species Composition and Seasonal Occurrence of Centric Diatoms in a Polluted Marine Environment. Pakistan Journal of Botany Vol 10, No 1, p 53-64, June.

These interchange motions also occur in plasmas that are in a system with a large centrifugal force. In a cylindrically symmetric plasma device, radial electric fields cause the plasma to rotate rapidly in a column around the axis. Acting opposite to the gravity in the simple model, the centrifugal force moves the plasma outward where the ripple-like perturbations (sometimes called “flute” instabilities) occur on the boundary.

If the fluid is incompressible then the equation can be simplified into . Since (to maintain pressure balance), the above equation shows that if the system is unstable. Physically, this means that if the field lines are toward the region of higher plasma density then the system is susceptible to interchange motions. To derive a more rigorous stability condition, the perturbations that cause an instability must be generalized.

Kelso, J.A.S., Tuller, B., Bateson, E. V., & Fowler, C.A. (1984). Functionally specific articulatory cooperation following jaw perturbations during speech: Evidence for coordinative structures. Journal of Experimental Psychology: Human Perception and Performance, 10, 812–832. In asking how synergies might be formed in motor systems Kelso turned from Sherringtonian neurophysiology to theories of self-organization in particular the fledgling interdisciplinary field of synergetics founded by Hermann Haken.

The planets were discovered through Doppler spectroscopy using the HARPS spectrograph at La Silla Observatory in Chile. Their presence was revealed by periodic variations in the radial velocity of the host star due to gravitational perturbations by the orbiting objects. In 2018, two more planets were confirmed. All planets have brief orbital periods: the four planets orbit every 5.76, 7.28, 10.86 and 25.2 days respectively.

Damping occurs at two different scales, with the process working more quickly over short ranges than over longer distances. Here, a short length is one that is lower than the mean free path of the photons. A long distance is one that is greater than the mean free path, if still less than the diffusion length. On the smaller scale, perturbations are damped almost instantaneously.

In methods of special perturbations, numerical datasets, representing values for the positions, velocities and accelerative forces on the bodies of interest, are made the basis of numerical integration of the differential equations of motion.Bate, Mueller, White (1971), pp. 387–409. In effect, the positions and velocities are perturbed directly, and no attempt is made to calculate the curves of the orbits or the orbital elements.Moulton (1914): ch.

Outside of England, Newton's theory took some time to become established. Descartes' theory of vortices held sway in France, and Huygens, Leibniz and Cassini accepted only parts of Newton's system, preferring their own philosophies. Voltaire published a popular account in 1738. In 1748, the French Academy of Sciences offered a reward for solving the perturbations of Jupiter and Saturn which was eventually solved by Euler and Lagrange.

Lightning can cause ionospheric perturbations in the D-region in one of two ways. The first is through VLF (very low frequency) radio waves launched into the magnetosphere. These so-called "whistler" mode waves can interact with radiation belt particles and cause them to precipitate onto the ionosphere, adding ionization to the D-region. These disturbances are called "lightning-induced electron precipitation" (LEP) events.

These perturbations are important, as they are responsible for the subtle physics that result in the cosmic microwave background anisotropy. In this epoch, the amplitude of perturbations that enter the horizon oscillate sinusoidally, with dense regions becoming more rarefied and then becoming dense again, with a frequency which is related to the size of the perturbation. If the perturbation oscillates an integral or half-integral number of times between coming into the horizon and recombination, it appears as an acoustic peak of the cosmic microwave background anisotropy. (A half-oscillation, in which a dense region becomes a rarefied region or vice versa, appears as a peak because the anisotropy is displayed as a power spectrum, so underdensities contribute to the power just as much as overdensities.) The physics that determines the detailed peak structure of the microwave background is complicated, but these oscillations provide the essence.

Animation of Himalia's orbit. At a distance of about from Jupiter, Himalia takes about 250 Earth days to complete one orbit around Jupiter. It is the largest member of the Himalia group, which are a group of small moons orbiting Jupiter at a distance from to , with inclined orbits at an angle of 27.5 degrees to Jupiter's equator. Their orbits are continuously changing due to solar and planetary perturbations.

The stratification of the Bächental level presents a trend of marine to mesosaline conditions, as it was part of a depocenter at the south of the path between the Bohemian Massif & the Vindelician land.Ruebsam, W., Müller, T., Kovács, J., Pálfy, J., & Schwark, L. (2018). Environmental response to the early Toarcian carbon cycle and climate perturbations in the northeastern part of the West Tethys shelf. Gondwana Research, 59, 144-158.

Reasonable results for LECA include the estimate of c. 1800 Mya. A 2300 Mya estimate also seems reasonable and has the added attraction of coinciding with one of the most pronounced biogeochemical perturbations in Earth history (the Great Oxygenation Event). The marked increase in atmospheric oxygen concentrations during the early Palaeoproterozoic Great Oxidation Event has been invoked as a contributing cause of eukaryogenesis – by inducing the evolution of oxygen-detoxifying mitochondria.

The shape of the light curve at the maximum was found to change with phase angle. The orbit of 50 Virginia places it in an 11:4 mean motion resonance with the planet Jupiter. The computed Lyapunov time for this asteroid is only 10,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets. Virginia has been studied by radar.

The orbit of 33 Polyhymnia puts it in a 22:9 mean motion resonance with the planet Jupiter. The computed Lyapunov time for this asteroid is 10,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets. Measurements of the position for this asteroid from 1854 to 1969 were used to determination the gravitational influence of Jupiter upon 33 Polyhymnia.

Satellites in Low Earth Orbit (LEO) with high ballistic coefficients experience smaller perturbations to their orbits due to atmospheric drag. The ballistic coefficient of an atmospheric reentry vehicle has a significant effect on its behavior. A very high ballistic coefficient vehicle would lose velocity very slowly and would impact the Earth's surface at higher speeds. In contrast, a low ballistic coefficient would reach subsonic speeds before reaching the ground.

Aethra (minor planet designation: 132 Aethra) is a metallic asteroid and Mars- crosser on an eccentric orbit from the asteroid belt. It measures approximately 40 kilometers in diameter. It was discovered by James Craig Watson in 1873 and is the first such Mars-crosser asteroid to be identified. As a Mars-crosser asteroid, Aethra is the lowest numbered asteroid to not have proper orbital elements due to recurring perturbations by Mars.

Osculating orbit (inner, black) and perturbed orbit (red) In astronomy, and in particular in astrodynamics, the osculating orbit of an object in space at a given moment in time is the gravitational Kepler orbit (i.e. an elliptic or other conic one) that it would have around its central body if perturbations were absent. That is, it is the orbit that coincides with the current orbital state vectors (position and velocity).

They may be said to live in symbiosis with their environment. The method which Prigogine used to study the stability of the dissipative structures to perturbations is of very great general interest. It makes it possible to study the most varied problems, such as city traffic problems, the stability of insect communities, the development of ordered biological structures and the growth of cancer cells to mention but a few examples.

These perturbations result in different arrangement of electrons in the excited state of the involved molecules and therefore in different effects. For example, the [4+2] Diels-Alder reactions can be assisted by heat whereas the [2+2] cycloaddition is selectively induced by light.Brückner, pp. 637–647 Because of the orbital character, the potential for developing stereoisomeric products upon cycloaddition is limited, as described by the Woodward–Hoffmann rules.

The Kolmogorov–Arnold–Moser (KAM) theorem is a result in dynamical systems about the persistence of quasiperiodic motions under small perturbations. The theorem partly resolves the small-divisor problem that arises in the perturbation theory of classical mechanics. The problem is whether or not a small perturbation of a conservative dynamical system results in a lasting quasiperiodic orbit. The original breakthrough to this problem was given by Andrey Kolmogorov in 1954.

Analysis of observed perturbations in the orbit of Uranus produced estimates of the suspected planet's position within a degree of where it was found. This could not have been accomplished with deferent/epicycle methods. Still, Newton in 1702 published Theory of the Moon's Motion which employed an epicycle and remained in use in China into the nineteenth century. Subsequent tables based on Newton's Theory could have approached arcminute accuracy.

All living organisms, whether unicellular or multicellular, exhibit homeostasis. To maintain dynamic equilibrium and effectively carry out certain functions, a system must detect and respond to perturbations. After the detection of a perturbation, a biological system normally responds through negative feedback that stabilize conditions by reducing or increasing the activity of an organ or system. One example is the release of glucagon when sugar levels are too low.

In 2007, Baer and Chesley calculated a higher mass and density for Parthenope based on perturbations by the 90 km asteroid 17 Thetis. Baer and Chesley calculated a mass of 6.3 kg with a density of 3.3 g/cm³. 2008 estimates by Baer suggest a mass of 6.15. The 1997 and 2001 estimates by Viateau and Rapaport were closer to 5 kg with a density of 2.7 g/cm³.

Their mass, consequently, is uncertain by about a factor of 10. For near-Earth asteroids without a well-determined diameter, Sentry assumes a generic albedo of 0.15. In August 2013, the Sentry Risk Table started using planetary ephemeris (DE431) for all NEO orbit determinations. DE431 (JPL small-body perturber ephemeris: SB431-BIG16) better models the gravitational perturbations of the planets and includes the 16 most massive main-belt asteroids.

A shock wave is undercompressive if the Lax conditions are not fulfilled. A sharp wave front may remain sharp whilst travelling even when perturbations behind the front travel slower than it. An experiment can be made to show this with travelling liquid steps : a thick film is spread on a thin one. The liquid steps remain sharp when they travel because the spreading is enhanced by the Marangoni effect.

He then became professor of astronomy at the University of Cincinnati, while working at the Cincinnati Observatory. His work included orbital motions of the Trojan asteroids, and particularly the orbit of 433 Eros. In 1951, he used twenty years worth of observations of Eros to determine the gravitational perturbations of the planets. From these, he calculated the most accurate masses to that date of Mercury, Venus, Mars and the Moon.

Nevertheless, there are important differences. First, ocean eddies are not perturbations on an energetic mean flow. They may play an important role in the poleward transport of heat. Second, they are relatively small in horizontal extent so that ocean climate models, which must have the same overall exterior dimensions as AGCMs, may require as much as 20 times the resolution as AGCM if the eddies are to be explicitly resolved.

Pumping removes helium vapor boil-off and controls the bath temperature. The helium vessel is often pumped to a pressure below helium's superfluid lambda point to take advantage of the superfluid's thermal properties. Because superfluid has very high thermal conductivity, it makes an excellent coolant. In addition, superfluids boil only at free surfaces, preventing the formation of bubbles on the surface of the cavity, which would cause mechanical perturbations.

The effect of radiation pressure from the Sun contributes an amount of ± to the lunar distance. Although the instantaneous uncertainty is sub-millimeter, the measured lunar distance can change by more than from the mean value throughout a typical month. These perturbations are well understood and the lunar distance can be accurately modeled over thousands of years. The Moon's distance from the Earth and Moon phases in 2014.

When the perturbations have grown sufficiently, a small region might become substantially denser than the mean density of the universe. At this point, the physics involved becomes substantially more complicated. When the deviations from homogeneity are small, the dark matter may be treated as a pressureless fluid and evolves by very simple equations. In regions which are significantly denser than the background, the full Newtonian theory of gravity must be included.

In one paper, he worked with George Johnstone Stoney on the perturbations of the Leonid meteors, predicting and explaining the spareness of the 1899 shower. He became superintendent of HM Nautical Almanac Office from 1891 until his retirement in 1910. He was elected a Fellow of the Royal Society in June 1896. He collaborated with his U.S. counterpart Simon Newcomb in establishing an international standard for astronomical constants.

These are small icy bodies with orbits between those of Jupiter and Neptune. Astronomers believe that Centaurs have been recently perturbed inward from the Kuiper belt, a disk of Trans-Neptunian Objects occupying a region extending from the orbit of Neptune to approximately 50 AU from the Sun. Frequent perturbations by Jupiter will likely accumulate and cause the comet to migrate either inward or outward by the year 4000.

The Insight lander with its solar panels deployed in a cleanroom The Principal Investigator for RISE is William Folkner of JPL, who led the 1997 investigation of Mars's core using the radio link between Earth and NASA's Mars Pathfinder (also included the Sojourner rover). RISE uses the spacecraft's radio connection with Earth to assess perturbations of Mars's rotation axis to within 10 centimeters.Mars InSight Landing Press Kit. (PDF) NASA.

The observations made by ABS tested the theory of inflation. Inflation is the leading theory of the very early universe; however, observational evidence for inflation is still inconclusive. Inflationary models generically predict that a gravitational-wave background (GWB) would have been produced along with the density perturbations that seed large-scale structure formation. Such a GWB would leave an imprint on both the temperature and polarization of the CMB.

For a feature descriptor to be useful, it needs to have certain invariances. In particular it needs to be invariant to translation, scaling, small perturbations, and, depending on the application, rotation. Translational invariance comes naturally to shape context. Scale invariance is obtained by normalizing all radial distances by the mean distance \alpha between all the point pairs in the shape although the median distance can also be used.

Chris Godfrey is now deputy-director of UNEXA; he sends his former crew-mates to investigate unexplained perturbations in the orbit of Pluto. They discover that not only are their fuel tanks holed, but a super-dense wandering planet dubbed "Planet X" is on course to decimate the solar system. This was the last of Hugh Walters' 'exploration' novels as his realistic approach could not envisage travel further afield.

No better worst-case time bound is possible because, for any fixed value of β smaller than one, there exist point sets in general position (small perturbations of a regular polygon) for which the β-skeleton is a dense graph with a quadratic number of edges. In the same quadratic time bound, the entire β-spectrum (the sequence of circle-based β-skeletons formed by varying β) may also be calculated.

If the poles move into the left half plane, the oscillation dies out exponentially to zero. If the poles move into the right half plane, the oscillation grows exponentially until something limits it. If the perturbation is very small, the magnitude of the equivalent Q is very large so that the amplitude changes slowly. If the perturbations are small and reverse after a short time, the envelope follows a ramp.

Diagram showing the physical processes inside the Earth that lead to the generation of magma. A to D are different plate tectonic settings. The plots above show the resulting perturbations in the pressure and temperature of Earth's geothermal gradient. Melting in the mantle requires one of three possible events to occur: an increase in temperature, a decrease in pressure, or the addition of volatiles to the system (a change in composition).

A model called the cell state splitter involves alternating cell contraction and expansion, initiated by a bistable organelle at the apical end of each cell. The organelle consists of microtubules and microfilaments in mechanical opposition. It responds to local mechanical perturbations caused by morphogenetic movements. These then trigger traveling embryonic differentiation waves of contraction or expansion over presumptive tissues that determine cell type and is followed by cell differentiation.

The moonlets were probably formed from the breakup of a larger satellite. It is estimated that the A Ring contains 7,000–8,000 propellers larger than 0.8 km in size and millions larger than 0.25 km. Similar moonlets may reside in the F Ring. There, "jets" of material may be due to collisions, initiated by perturbations from the nearby small moon Prometheus, of these moonlets with the core of the F Ring.

Because of the movement of Earth around the Earth–Moon center of mass, the apparent path of the Sun wobbles slightly, with a period of about one month. Because of further perturbations by the other planets of the Solar System, the Earth–Moon barycenter wobbles slightly around a mean position in a complex fashion. The ecliptic is actually the apparent path of the Sun throughout the course of a year. , p.

Perturbations of chromatin structure can cause inappropriate gene expression and genomic instability, resulting in cellular transformation and malignant outgrowth. Polycomb group proteins (PcG) function as transcriptional repressors that silence specific sets of genes through chromatin modification. Although they are primarily known for their role in maintaining cell identity during the establishment of the body plan, several mammalian PcG members are implicated in the control of cellular proliferation and neoplastic development.

Apsidal precession—The major axis of Moon's elliptical orbit rotates by one complete revolution once every 8.85 years. In this image, the elliptical shape of the Moon's orbit is vastly exaggerated from its almost circular shape to make the precession visible. Orbital inclination—the Moon's orbit is inclined by 5.14° to the ecliptic. Earth's lunar orbit perturbations The orientation of the orbit is not fixed in space, but rotates over time.

Electrical pulses are also used to intracellularly deliver siRNA into cells. The cell membrane is made of phospholipids which makes it susceptible to an electric field. When quick but powerful electrical pulses are initiated the lipid molecules reorient themselves, while undergoing thermal phase transitions because of heating. This results in the making of hydrophilic pores and localized perturbations in the lipid bilayer cell membrane also causing a temporary loss of semipermeability.

The gravitational perturbations of the other planets in the Solar System combine to modify the orbit of the Earth and the orientation of its rotation axis. These changes can influence the planetary climate. Despite such interactions, highly accurate simulations show that overall, Earth's orbit is likely to remain dynamically stable for billions of years into the future. In all 1,600 simulations, the planet's semimajor axis, eccentricity, and inclination remained nearly constant.

In this approach, interactions between different atomic sites are considered as perturbations. There exist several kinds of interactions we must consider. The crystal Hamiltonian is only approximately a sum of atomic Hamiltonians located at different sites and atomic wave functions overlap adjacent atomic sites in the crystal, and so are not accurate representations of the exact wave function. There are further explanations in the next section with some mathematical expressions.

Comets are in unstable orbits that evolve over time due to perturbations and outgassing. Tempel 1 passed within 0.04 AU – or 5.9 million km (3.7 million mi) – of the dwarf planet Ceres on November 11, 2011. Then, as a Jupiter-family comet, it will spend years interacting with the giant planet Jupiter, finally passing within 0.02 AU – or 3.0 million km (1.9 million mi) – of Mars on October 17, 2183.

This is supported by the rhythmic behavior of the brain. Harmonic oscillators have the capability to reproduce a perturbation that happened in previous cycles. It follows that when the brain is unperturbed, such as during sleep, it is in essence rehearsing the perturbations of the day. Recent studies have confirmed that off wave states, such as slow-wave sleep, play a part in consolidation as well as REM sleep.

This would be the First (of what since then has become the biennial) Texas Symposium on Relativistic Astrophysics.Roy Kerr (2009) Afterword, page 125 of Cracking the Einstein Code by Fulvio Melia Kerr presented to the Symposium his solution to the Einstein field equations.Kerr, R.P., 1963, Physical Review Letters, 11, 237. In 1965, with Alfred Schild, he introduced the concept of Kerr-Schild perturbations and developed the Kerr- Newman metric.

Zanardi and Rasetti called these DF states "error avoiding codes". Subsequently, Daniel A. Lidar proposed the title "decoherence-free subspace" for the space in which these DF states exist. Lidar studied the strength of DF states against perturbations and discovered that the coherence prevalent in DF states can be upset by evolution of the system Hamiltonian. This observation discerned another prerequisite for the possible use of DF states for quantum computation.

Theseus1 is commonly believed to be able to detect changes in the cell wall and respond to perturbations. This thought has been applied to a few different scenarios. First, it has been considered that THE1 detects fragments of cell walls, and then signals for the inhibition of cell elongation. Another proposition is that THE1 responds to changes in the cell wall composition before signalling for the inhibition of cell elongation.

The following considers perturbations about a nominal straight and level flight path. To keep the analysis (relatively) simple, the control surfaces are assumed fixed throughout the motion, this is stick-fixed stability. Stick-free analysis requires the further complication of taking the motion of the control surfaces into account. Furthermore, the flight is assumed to take place in still air, and the aircraft is treated as a rigid body.

The natural dynamics keep the spacecraft (or natural celestial body) in the vicinity of the Lagrangian point without use of a propulsion system, even when slightly perturbed from equilibrium. These orbits can however be destabilized by other nearby massive objects. For example, orbits around the and points in the Earth–Moon system can last only a few million years instead of billions because of perturbations by the planets.

This is a binary star system with an orbital period of 52.1 days and an eccentricity of 0.22. Only the primary star can be directly detected, via Doppler shifts or perturbations around the system's barycenter. Using spectroscopy and astrometry, the nature of the secondary star can be inferred. The primary star is an F-type main-sequence star with a stellar classification of F8V, 4% more massive than the Sun.

The model showed that under certain constraints, second-order interactions between electrons could be modelled as bosonic interactions. In 1963, J.M. Luttinger reformulated the theory in terms of Bloch sound waves and showed that the constraints proposed by Tomonaga were unnecessary in order to treat the second-order perturbations as bosons. But his solution of the model was incorrect; the correct solution was given by and Elliot H. Lieb 1965.

Zeta Cancri can be resolved as a binary star in small telescopes. Its binary nature was discovered in 1756 by Tobias Mayer. William Herschel resolved the two components that make up Zeta¹ Cancri in 1781. As early as 1831, John Herschel noticed perturbations in Zeta² Cancri's orbit around Zeta¹; this led Otto Wilhelm von Struve, in 1871, to postulate a fourth, unseen, component which orbited closely the visible member of Zeta².

Bred vectors are created by adding initially random perturbations to a nonlinear model. The control (unperturbed) and the perturbed models are integrated in time, and periodically the control solution is subtracted from the perturbed solution. This difference is the bred vector. The vector is scaled to be the same size as the initial perturbation, and is then added back to the control to create the new perturbed initial condition.

Most systems that involve multiple gravitational attractions present one primary body which is dominant in its effects (for example, a star, in the case of the star and its planet, or a planet, in the case of the planet and its satellite). The gravitational effects of the other bodies can be treated as perturbations of the hypothetical unperturbed motion of the planet or satellite around its primary body.

It is named after Semele, the mother of Dionysus in Greek mythology. The orbit of 86 Semele places it in a 13:6 mean motion resonance with the planet Jupiter. The computed Lyapunov time for this asteroid is only 6,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets. This Lyapunov time is the second lowest among the first 100 named minor planets.

No excess infrared emission has been detected, which may indicate the lack of a debris disk in orbit around it. Radial velocity measurements of this star using the Near Infrared Spectrometer (NIRSPEC) instrument at the Keck II observatory have not revealed any variations that might otherwise indicate the presence of an orbiting companion. This instrumentation is sensitive enough to detect the gravitational perturbations of massive, short period companions with the mass of Neptune or greater.

Much labour was bestowed by him upon facilitating the computation of the movements of the asteroids. With this end in view he expounded to the Berlin Academy in 1849 a mode of determining an elliptic orbit from three observations, and communicated to that body in 1851 a new method of calculating planetary perturbations by means of rectangular coordinates (republished in W. Ostwald's Klassiker der exacten Wissenschaften, No. 141, 1903). Encke visited England in 1840.

If areas of high CAPE exist in the β-skirt, the deep convection that forms would act as a source of vorticity and turbulence kinetic energy. This small-scale energy will upscale into a jet around the storm. The low-level jet focuses the stochastic energy a nearly axisymmetric ring around the eye. Once this low-level jet forms, a positive feedback cycle such as WISHE can amplify the initial perturbations into a secondary eyewall.

Toth, Z. and Kalnay, E. (1997), "Ensemble Forecasting at NCEP and the Breeding Method", Monthly Weather Review, 125, pp. 3298. This technique is not guaranteed to yield an ensemble distribution identical to the actual forecast distribution, but attaining such probabilistic information is one goal of the choice of initial perturbations. Other variants of ensemble forecasting systems that have no immediate probabilistic interpretation include those that assemble the forecasts produced by different numerical weather prediction systems.

Incorrect orbital calculations initially resulted in 56 Melete being mistaken for a second sighting of Daphne. Daphne was not sighted again until August 31, 1862. The orbit of 41 Daphne places it in a 9:22 mean motion resonance with the planet Mars. The computed Lyapunov time for this asteroid is 14,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.

The overall gain spectrum can be derived analytically, as is shown below. Random perturbations will generally contain a broad range of frequency components, and so will cause the generation of spectral sidebands which reflect the underlying gain spectrum. The tendency of a perturbing signal to grow makes modulation instability a form of amplification. By tuning an input signal to a peak of the gain spectrum, it is possible to create an optical amplifier.

A number of periodic comets discovered in earlier decades or previous centuries are now lost comets. Their orbits were never known well enough to predict future appearances or the comets have disintegrated. However, occasionally a "new" comet is discovered, and calculation of its orbit shows it to be an old "lost" comet. An example is Comet 11P/Tempel–Swift–LINEAR, discovered in 1869 but unobservable after 1908 because of perturbations by Jupiter.

This minor planet was named after Hans Osten (1875–1936) a German amateur astronomer, orbit computer and business man. As a non-professional, Osten attracted attention with his precises calculations of comets and asteroids. He is known for calculating the orbit of 447 Valentine, taking into account perturbations by all major planets with such precision, that it was considered exemplary in the astronomical community. Osten received the silver Leibniz Medal in 1911.

Persisting correlated neural activity—without a homeostatic feedback loop—causes LTP mechanisms to continually up regulate synaptic connection strengths. Unspecified strengthening of synaptic weights causes neural activity to become unstable to the point that insignificant stimulatory perturbations can trigger chaotic, synchronous network-wide firing known as bursts. This renders the neural network incapable of computing. Since homeostatic plasticity normalizes the synaptic strengths of all neurons in a network, the overall neural network activity stabilizes.

However, the complexity term of variational free energy shares the same fixed point as Helmholtz free energy (under the assumption the system is thermodynamically closed but not isolated). This is because if sensory perturbations are suspended (for a suitably long period of time), complexity is minimised (because accuracy can be neglected). At this point, the system is at equilibrium and internal states minimise Helmholtz free energy, by the principle of minimum energy.Jarzynski, C. (1997).

Diagram of a Northern hemisphere hurricane Tropical cyclones are areas of relatively low pressure in the troposphere, with the largest pressure perturbations occurring at low altitudes near the surface. On Earth, the pressures recorded at the centers of tropical cyclones are among the lowest ever observed at sea level. The environment near the center of tropical cyclones is warmer than the surroundings at all altitudes, thus they are characterized as "warm core" systems.

Spin-polarized electron energy loss spectroscopy or SPEELS is a technique that is mainly used to measure the dispersion relation of the collective excitations, over the whole Brillouin zone. Spin waves are collective perturbations in a magnetic solid. Their properties depend on their wavelength (or wave vector). For long wavelength (short wave vector) spin wave the resulting spin precession has a very low frequency and the spin waves can be treated classically.

Like most other regular planetary moons, Callisto's rotation is locked to be synchronous with its orbit. The length of Callisto's day, simultaneously its orbital period, is about 16.7 Earth days. Its orbit is very slightly eccentric and inclined to the Jovian equator, with the eccentricity and inclination changing quasi-periodically due to solar and planetary gravitational perturbations on a timescale of centuries. The ranges of change are 0.0072–0.0076 and 0.20–0.60°, respectively.

The mix of air at supersonic and subsonic velocity creates shock waves that can slow the airplane. Turning to the mathematics of transonic flow, she showed that specially designed shockless airfoils could not, in fact, prevent shocks. Shocks developed in response to even small perturbations, such as a gust of wind or an imperfection in a wing.Chang, Kenneth, Cathleen Morawetz, 94; used math in study of motion, New York Times, August 13, 2017, p.

Different astrodynamics theories are used to maintain these catalogs. The General Perturbations (GP) theory provides a general analytical solution of the satellite equations of motion. The orbital elements and their associated partial derivatives are expressed as series expansions in terms of the initial conditions of these differential equations. The GP theories operated efficiently on the earliest electronic computing machines, and were therefore adopted as the primary theory for Space Catalog orbit determination.

The principal unexpected characteristic in the release dynamics was the high, 1.4 to 2.6 km/s, initial Ba expansion velocity relative to an expected velocity of 0.9 km/s. Attention was also given to neutral cloud expansion, initial ion cloud expansion, convective motion, and the characteristics of field-aligned motion. The possibility of measuring parallel electric fields over the polar cap by observing perturbations in the motion of the visible ions was assessed.

This constant tug-of-war is mediated by the controller, which offsets the bias current by equal and opposite perturbations of current as the rotor deviates from its center position. The gap sensors are usually inductive in nature and sense in a differential mode. The power amplifiers in a modern commercial application are solid state devices which operate in a pulse width modulation configuration. The controller is usually a microprocessor or digital signal processor.

Signal isolation may be used to pass the signal from the source to the measuring device without a physical connection. It is often used to isolate possible sources of signal perturbations that could otherwise follow the electrical path from the sensor to the processing circuitry. In some situations, it may be important to isolate the potentially expensive equipment used to process the signal after conditioning from the sensor. Magnetic or optical isolation can be used.

Field Aligned Irregularities (FAIs) are anisotropic (different values when measured in different directions) perturbations of plasma density associated with magnetic fields. FAIs are often thought of in the context of the Earth's ionosphere where several natural processes generate FAIs in the E-region and F-region. They occur at 50 and 140 MHz, where electrons associated with the event become vertically aligned with Earth's magnetic field. FAI may occur for several hours after it starts.

3-D map of the large-scale distribution of dark matter, reconstructed from measurements of weak gravitational lensing with the Hubble Space Telescope. Structure formation refers to the period after the Big Bang when density perturbations collapsed to form stars, galaxies, and clusters. Prior to structure formation, the Friedmann solutions to general relativity describe a homogeneous universe. Later, small anisotropies gradually grew and condensed the homogeneous universe into stars, galaxies and larger structures.

As the Universe grows, its temperature drops, which leaves less energy [per unit volume of space] available to perform work in the future than was available in the past. Additionally, perturbations in the energy density grow (eventually forming galaxies and stars). Thus the Universe itself has a well-defined thermodynamic arrow of time. But this does not address the question of why the initial state of the universe was that of low entropy.

He is noted for his work in the area of inflation model building and the observational consequences of models of inflation. In 1997, he discovered the Lyth bound which relates the tensor-scalar ratio of perturbations in the CMB to the variation of the inflaton field during inflation. He proposed the Curvaton Scenario in 2001, with David Wands of Portsmouth University. He was awarded the Fred Hoyle Medal and Prize in 2012.

As measured by a force platform, parameters used to measure postural stability. Adapted from McCrory et al. 2010 Under dynamic postural stability, which can be defined as the response to anterior (front) and posterior (back) translation perturbations, the effects of pregnancy are different. Initial sway, total sway, and sway velocity (see figure for description of variables) are significantly less during the third trimester than during the second trimester and when compared to non-pregnant women.

Mbonye's parents (Reuben Rwabuzisoni, father) were teachers. His high school education was at Nyakasura School in Uganda. He attended Fourah Bay College in Sierra Leone, then obtained his doctoral degree from the University of Connecticut in 1996. His Ph.D. dissertation on “Gravitational Perturbations of Radiating Spacetimes” along with his founding of and activities in the “Rwanda Education Reconstruction Effort” (RERE) earned him the 1996 Ph.D. "Graduate of the Year" at the University of Connecticut.

24 Themis was discovered on 5 April 1853 by Annibale de Gasparis of Naples, though it was given its name by fellow Italian astronomer Angelo Secchi. The asteroid was named after Themis, the Greek goddess of law. Gravitational perturbations in the orbit of Themis were used to calculate the mass of Jupiter as early as 1875. On 24 December 1975, 24 Themis had a close encounter with 2296 Kugultinov with a minimum distance of .

Warm dark matter comprises particles with an FSL comparable to the size of a protogalaxy. Predictions based on warm dark matter are similar to those for cold dark matter on large scales, but with less small-scale density perturbations. This reduces the predicted abundance of dwarf galaxies and may lead to lower density of dark matter in the central parts of large galaxies. Some researchers consider this a better fit to observations.

Moser and Arnold expanded the ideas of Kolmogorov (who was inspired by questions of Poincaré) and gave rise to what is now known as Kolmogorov–Arnold–Moser theorem (or "KAM theory"), which concerns the persistence of some quasi- periodic motions (nearly integrable Hamiltonian systems) when they are perturbed. KAM theory shows that, despite the perturbations, such systems can be stable over an infinite period of time, and specifies what the conditions for this are.

It acts without being acted upon. In General Relativity, every separate local quantity which is used to describe the geometry is itself a local dynamical field, with its own equation of motion. This produces severe restrictions, because the equation of motion has to be a sensible one. It must determine the future from initial conditions, it must not have runaway instabilities for small perturbations, it must define a positive definite energy for small deviations.

The 4D/RCS architecture is characterized by a generic control node at all the hierarchical control levels. The 4D/RCS hierarchical levels are scalable to facilitate systems of any degree of complexity. Each node within the hierarchy functions as a goal-driven, model-based, closed-loop controller. Each node is capable of accepting and decomposing task commands with goals into actions that accomplish task goals despite unexpected conditions and dynamic perturbations in the world.

A possible explanation is the encounter of two streamers and the production of high-energy run-away electrons; however, microscopic simulations have shown that the duration of electric field enhancement between two streamers is too short to produce a significantly number of run-away electrons. Recently, it has been proposed that air perturbations in the vicinity of streamers can facilitate the production of run-away electrons and hence of X-rays from discharges.

Freelance member of the Department of Geometry and Topology of the Steklov Institute of Mathematics. Area of scientific interests: theory of integrable systems in geometry and physics: Frobenius manifolds, Gromov–Witten invariants, singularity theory, normal forms of integrable partial differential equations, Hamiltonian perturbations of hyperbolic systems, geometry of isomonodromic deformations, theta functions on Riemann surfaces, and nonlinear waves. In 1998 he was an Invited Speaker of the International Congress of Mathematicians in Berlin.

In addition to supernovae, gamma-ray bursts, excessive amounts of radiation, gravitational perturbations and various other events have been proposed to affect the distribution of life within the galaxy. These include, controversially, such proposals as "galactic tides" with the potential to induce cometary impacts or even cold bodies of dark matter that pass through organisms and induce genetic mutations. However, the impact of many of these events may be difficult to quantify.

Pressure perturbations within an extent of a thunderstorm are noteworthy. With buoyancy rapid within the lower and mid- levels of a mature thunderstorm, one might believe that low pressure dominates in the mesoscale environment. However, this is not the case. With downdrafts ushering colder air from mid-levels, hitting ground and propagating away in all directions, high pressure is to be found widely at surface levels, usually indicative of strong (potentially damaging) winds.

The planet is most likely frigid, with an estimated surface temperature of about , and lies outside Barnard Star's presumed habitable zone. However, more work is needed on the planet's atmospherics to better understand surface conditions. Direct imaging of the planet and its tell-tale light signature are possible in the decade after its discovery. Further faint and unaccounted for perturbations in the system suggest there may be a second planetary companion even further out.

Hu (1995-08-26), p. 136-8Hu & White (1997-04-20), p. 568-9 Though general diffusion damping can damp perturbations in collisionless dark matter simply due to photon dispersion, the term Silk damping applies only to damping of adiabatic models of baryonic matter, which is coupled to the diffusing photons, not dark matter, and diffuses with them. Silk damping is not as significant in models of cosmological development which posit early isocurvature fluctuations (i.e.

Ergodic theory (Greek: ' "work", ' "way") is a branch of mathematics that studies statistical properties of deterministic dynamical systems. In this context, statistical properties means properties which are expressed through the behavior of time averages of various functions along trajectories of dynamical systems. The notion of deterministic dynamical systems assumes that the equations determining the dynamics do not contain any random perturbations, noise, etc. Thus, the statistics with which we are concerned are properties of the dynamics.

A team of astronomers led by Stéphane Udry of the Geneva Observatory used the HARPS instrument on the European Southern Observatory 3.6 meter telescope in La Silla, Chile, to discover the planet in 2007. Udry's team employed the radial velocity technique, in which the mass of a planet is determined based on the small perturbations it induces in its parent star's orbit via gravity."The HARPS search for southern extra-solar planets" , S. Udry. X. Bonfils.

If all inhomogeneities would be purely random perturbations of the climate records, collectively their effect on the mean global climate signal would be negligible. However, certain changes are typical for certain periods and occurred in many stations, these are the most important causes as they can collectively lead to artificial biases in climate trends across large regions. Menne, M. J., Williams, C. N. jr., and Palecki M. A.: "On the reliability of the U.S. surface temperature record".

Protoplanetary disk surrounding the young star Elias 2-27, located some 450 light years away. In 2016, it was discovered that disc perturbations from density waves organized the disc debris into a pinwheel structure, with sweeping spiral arms; using observations from the Atacama Large Millimeter Array (ALMA) radio telescope. This marks the first instance of such an observation in a protoplanetary disc, though they have been previously predicted. The spiral arms start at and extend out to .

Information Sciences. 177 (4):1088-1122, 2007 in 2007. The detector uses the algorithms to more efficiently remove background noise and so more easily identify features which can be used in a 3D model. As the detector scans images it uses the three basics of global transformation, local perturbations and intra-class variations to define the areas of search, and identifies unique regions of those images rather than using the more traditional corner or blob searches.

The electrons of a system will occupy the lowest Kohn–Sham eigenstates up to a given energy level according to the Aufbau principle. This corresponds to the steplike Fermi–Dirac distribution at absolute zero. If there are several degenerate or close to degenerate eigenstates at the Fermi level, it is possible to get convergence problems, since very small perturbations may change the electron occupation. One way of damping these oscillations is to smear the electrons, i.e.

This enzyme participates in pyrimidine metabolism. This enzyme has a dual function: on one hand, it removes dUTP from the deoxynucleotide pool, which reduces the probability of this base being incorporated into DNA by DNA polymerases, while on the other hand, it produces the dTTP precursor dUMP. Lack or inhibition of dUTPase action leads to harmful perturbations in the nucleotide pool resulting in increased uracil content of DNA that activates a hyperactive futile cycle of DNA repair.

In 2014, Bellone applied to the University of Lausanne to start her own lab. Funded by the Swiss National Science Foundation, Bellone became an Assistant Professor in the Department of Fundamental Neuroscience at the University of Lausanne. Her lab at UNIL focused on understanding the development of the brain's reward circuitry, the mesocorticolimbic dopamine system, in mouse models. Using various techniques, both in vivo and ex vivo, Bellone explored how perturbations to this circuitry affect social motivation.

Reflexes are a vital part of our everyday activities. We have all experienced how fast and automatic these responses to environmental interactions can be. They can protect us from potentially dangerous situations such as touching a hot stove or stepping on a tack. There are also reflex pathways involved in more dynamic activities such as walking and running, helping to ensure a smooth gait and allowing us to respond quickly to obstacles or unexpected perturbations or disturbances.

The orbits of centaurs are unstable due to perturbations by the giant planets. Nessus is an "SE object" because currently Saturn controls its perihelion and its aphelion is within the Kuiper belt. It is estimated to have a relatively long orbital half-life of about 4.9 million years. Fifty clones of the orbit of Nessus suggest that it will not pass within 1 AU (or 150 million kilometers) of any planet for at least 20,000 years.

The two spacecraft used for the ANDE mission are the Mock ANDE Active (MAA) sphere (Navy-OSCAR 61) and the Fence Calibration (FCAL) sphere (OSCAR 62). These microsatellites, developed by the Naval Research Laboratory, will measure drag through the use of precision orbit determination. Ground-based lasers will be used to track the orbits of the sphere to with a couple centimeters of accuracy. Perturbations caused by density gradients and winds will be backed out from these measurements.

Periastron precession is the rotation of a planet's orbit within the orbital plane, i.e. the axes of the ellipse change direction. In the Solar System, perturbations from other planets are the main cause, but for close-in exoplanets the largest factor can be tidal forces between the star and planet. For close-in exoplanets, the general relativistic contribution to the precession is also significant and can be orders of magnitude larger than the same effect for Mercury.

The complexities of the different visco-elastic length- and velocity-force relationships of these subparts provides the opportunity for the adaptive selection of structurally complex muscle biocomposites with highly task-tuned nonlinear visco-elastic length- velocity- force relationships. This nature of muscles to be composite structures thus provides the adaptive opportunity for evolution to modify the visco-elastic reactions of the musculoskeletal system so they counteract perturbations without the need for spinal or higher levels of control.

Confidence accounting is a method of accounting whereby some of the figures are expressed not as single point estimates, but rather as probability distributions. Under Confidence Accounting, the end results of audits would be presentations of distributions for major entries in the profit & loss, balance sheet and cashflow statements. The proposed benefits of Confidence Accounting include a fairer representation of financial results, reduced footnotes, more measurable audit quality and a mitigation of mark-to-market perturbations.

It is sometimes asserted that the length of the current interglacial temperature peak will be similar to the length of the preceding interglacial peak (Sangamonian/Eem Stage). Therefore, we might be nearing the end of this warm period. However, this conclusion is probably mistaken: the lengths of previous interglacials were not particularly regular (see graphic at right). Berger and Loutre (2002) argue that “with or without human perturbations, the current warm climate may last another 50,000 years.

The geocentric orbit of is chaotic due to the combined effects of tidal forces from the Sun and Earth as well as repeated close encounters with the Moon. The Moon gravitationally perturbs 's geocentric orbit, causing it to be unstable. Over the course of 's orbit around Earth, repeated close encounters with the Moon will eventually lead to ejection from its geocentric orbit as the Moon's perturbations can transfer enough momentum for to escape Earth's gravitational influence.

Relativistic effects in chemistry can be considered to be perturbations, or small corrections, to the non-relativistic theory of chemistry, which is developed from the solutions of the Schrödinger equation. These corrections affect the electrons differently depending on the electron speed relative to the speed of light. Relativistic effects are more prominent in heavy elements because only in these elements do electrons attain sufficient speeds for the elements to have properties that differ from what non-relativistic chemistry predicts.

A transiting exocomet around HD 182952 (KIC 8027456) is the first exocomet found in an automated search for transiting exocomets. Irregular dimming events around KIC 8462852 have been interpreted as exocomets, but the shape of the dips are different from discovered exocomet transits. During formation of the Oort Cloud through planetary perturbations, stellar encounters, and the galactic tide, a comet can be ejected and leave the solar system. Binary systems are another possible source of ejected exocomets.

Insect eyes are unable to move independently of the head. In order for flies to stabilize their visual fields, they must adjust the position of their entire head. Sensory inputs detected by halteres not only determine the position of the body, but also, the position of the head, which can move independently from the body. Halteres are particularly useful for detecting fast perturbations during flight and only respond to angular velocities (speeds of rotation) above a certain threshold.

He was born in Länghem, in Västergötland, Sweden and graduated from Uppsala University in 1872. After getting his doctorate in 1875, he emigrated to Russia in 1876. He worked at Dorpat Observatory, in today's Tartu, Estonia, and then in 1879 worked at Pulkovo Observatory, becoming director of the observatory from 1895 until his death. He specialized in celestial mechanics, and notably worked on calculating the orbit of Comet Encke, taking into account the perturbations of various planets.

Without the perturbations from the terrestrial planets the Lyapunov time would be close to 10,000 years. The initial observations that showed its chaotic behavior were made by Wiśniewski. The low inclination (0.47°) of the orbit allows frequent transits, where the inner planets Mercury, Venus, Earth, and Mars can appear to cross the Sun as seen from the perspective of Toutatis. Earth did this in January 2009, July 2012 and July 2016, and will also do so in 2020.

Asteroid families are thought to have lifetimes of the order of a billion years, depending on various factors (e.g. smaller asteroids are lost faster). This is significantly shorter than the Solar System's age, so few if any are relics of the early Solar System. Decay of families occurs both because of slow dissipation of the orbits due to perturbations from Jupiter or other large bodies, and because of collisions between asteroids which grind them down to small bodies.

This approach draws heavily on the use of Newtonian like analogue and usually has as it starting point the FRW background around which perturbations are developed. The approach is non-local and coordinate dependent but gauge invariant as the resulting linear framework is built from a specified family of background hyper-surfaces which are linked by gauge preserving mappings to foliate the space-time. Although intuitive this approach does not deal well with the nonlinearities natural to general relativity.

The SOLCON instrument is designed to accurately measure the solar constant and identify variations in the value during a solar cycle. SOLCON measures the solar irradiance in space to avoid perturbations by the atmosphere of the Earth. It is also used as a reference to construct a long-duration time series of the solar irradiance. This data will ensure continuity of the solar constant level obtained by instruments mounted on free flyers, over climate time-scale duration.

Trurl therefore makes a modified Maxwell's demon for him, an entity that looks at moving particles of gas and reads information that is, coincidentally, encoded in their random perturbations. This way, all the information in the universe becomes easily available. The demon prints out this information on a long paper tape, but before the pirate realizes most of the information is completely useless (although strictly factual) he is buried under the endless rolls of tape, ceasing to bother anyone.

The inner group includes those satellites closer to Uranus (a < 0.15 rH) and moderately eccentric (~0.2), namely Francisco, Caliban, Stephano, and Trinculo. The outer group (a > 0.15 rH) includes satellites with high eccentricity (~0.5): Sycorax, Prospero, Setebos, and Ferdinand. The intermediate inclinations 60° < i < 140° are devoid of known moons due to the Kozai instability. In this instability region, solar perturbations at apoapse cause the moons to acquire large eccentricities that lead to collisions with inner satellites or ejection.

Because the orbital period is fairly close to being double that of the giant planet Jupiter, 175 Andromache initially became of interest in the study of gravitational perturbations. Based upon its spectrum, this is classified as a C-type asteroid. It has a diameter estimated in the range 101–107 km with a roughly circular shape. The size ratio between the major and minor axes is 1.09 ± 0.09, as determined from the W. M. Keck Observatory.

Blank focuses in his research on fundamental and applied aspects of microbial metabolism. Of specific interest is the interaction between the metabolic network and the introduced genetic and environmental perturbations. The research on in silico/in vivo metabolic network operation is aimed at a deeper understanding of cell function, with the ultimate goal of rational cell engineering. He is associate editor of Engineering in Life Sciences, Microbial Biotechnology, Fungal Biology and Biotechnology, and Metabolic Engineering Communication.

Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are considered in two-body systems using a Kepler orbit. There are many different ways to mathematically describe the same orbit, but certain schemes, each consisting of a set of six parameters, are commonly used in astronomy and orbital mechanics. A real orbit and its elements change over time due to gravitational perturbations by other objects and the effects of general relativity.

Paranal These are asteroids in a near-Earth orbit without the tail or coma of a comet. , 22,261 near-Earth asteroids are known, 1,955 of which are both sufficiently large and come sufficiently close to Earth to be considered potentially hazardous. NEAs survive in their orbits for just a few million years. They are eventually eliminated by planetary perturbations, causing ejection from the Solar System or a collision with the Sun, a planet, or other celestial body.

Pavel Karlovich Shternberg (; April 2, 1865 – February 1, 1920, both dates New Style) was a Russian astronomer and revolutionary. Shternberg contributed to the abolition of the Czarist government by Alexander Kerensky during the February Revolution of 1917. He was friends with two notable Communists, Vladimir Lenin and Leon Trotsky. His significant astronomical contributions include discovery of the planetary perturbations, the measurement of the latitude of the Moscow Astronomical Observatory, and the application of photography to astronomy.

The historical perturbation hypothesis proposes the low species richness of higher latitudes is a consequence of an insufficient time period available for species to colonize or recolonize areas because of historical perturbations such as glaciation (Brown and Lomolino 1998, Gaston and Blackburn 2000). This hypothesis suggests that diversity in the temperate regions has not yet reached equilibrium and that the number of species in temperate areas will continue to increase until saturated (Clarke and Crame 2003).

In the absence of perturbations, the ball will always roll downhill and therefore will tend to stay in the valley (or stable state). State shifts can be viewed from two different viewpoints, the "community perspective" and the "ecosystem perspective". The ball can only move between stable states in two ways: (1) moving the ball or (2) altering the landscape. The community perspective is analogous to moving the ball, while the ecosystem perspective is analogous to altering the landscape.

By their very nature, basins of attraction display resilience. Ecosystems are resistant to state shifts – they will only undergo shifts under substantial perturbations – but some states are more resilient than others. In the ball-and-cup model, a valley with steep sides has greater resilience than a shallow valley, since it would take more force to push the ball up the hill and out of the valley. Resilience can change in stable states when environmental parameters are shifted.

Robustness of a biological system (also called biological or genetic robustness) is the persistence of a certain characteristic or trait in a system under perturbations or conditions of uncertainty. Robustness in development is known as canalization. According to the kind of perturbation involved, robustness can be classified as mutational, environmental, recombinational, or behavioral robustness etc. Robustness is achieved through the combination of many genetic and molecular mechanisms and can evolve by either direct or indirect selection.

The Ok Tedi River is contaminated by tailings from a nearby mine. The implantation of a mine is a major habitat modification, and smaller perturbations occur on a larger scale than exploitation site, mine-waste residuals contamination of the environment for example. Adverse effects can be observed long after the end of the mine activity. Destruction or drastic modification of the original site and anthropogenic substances release can have major impact on biodiversity in the area.

The Weyl tensor is algebraically special, in fact it has Petrov type D. The global structure is known. Topologically, the homotopy type of the Kerr spacetime can be simply characterized as a line with circles attached at each integer point. Note that the inner Kerr geometry is unstable with regard to perturbations in the interior region. This instability means that although the Kerr metric is axis-symmetric, a black hole created through gravitational collapse may not be so.

Both the large size and noise that is associated with scRNA-seq will likely require new and powerful computational methods and bioinformatics pipelines to better make sense of the resulting data. Another challenge associated with this protocol is the creation of large scale CRISPR libraries. The preparation of these extensive libraries depends upon a comparative increase in the resources required to culture the massive numbers of cells that are needed to achieve a successful screen of many perturbations.

Cranial bones can also be useful for detecting evidence of physiological perturbations. The reconstructed frontal, parietal, and occipital bone fragments of Anzick-1 were analyzed for these indicators of health; however, the crania showed no evidence of cribra orbitalia or porotic hyperostosis, conditions that can indicate diseases. Porotic hyperostosis is characterized by porous lesions on the parietal, occipital, and sometimes frontal bones. Cribra orbitalia is another pathological skeletal lesion that manifests as porosity on the orbital roof.

The flow is completely unidirectional for low Dean numbers (De < 40~60). As the Dean number increases between 40~60 to 64~75, some wavy perturbations can be observed in the cross-section, which evidences some secondary flow. At higher Dean numbers than that (De > 64~75) the pair of Dean vortices becomes stable, indicating a primary dynamic instability. A secondary instability appears for De > 75~200, where the vortices present undulations, twisting, and eventually merging and pair splitting.

It was the first plant genome to be sequenced, completed in 2000 by the Arabidopsis Genome Initiative. The most up-to-date version of the A. thaliana genome is maintained by the Arabidopsis Information Resource (TAIR). Much work has been done to assign functions to its 27,000 genes and the 35,000 proteins they encode. Post-genomic research, such as metabolomics, has also provided useful insights to the metabolism of this species and how environmental perturbations can affect metabolic processes.

In methods of general perturbations, general differential equations, either of motion or of change in the orbital elements, are solved analytically, usually by series expansions. The result is usually expressed in terms of algebraic and trigonometric functions of the orbital elements of the body in question and the perturbing bodies. This can be applied generally to many different sets of conditions, and is not specific to any particular set of gravitating objects.Bate, Mueller, White (1971): p.

The science behind the concept is disputed. ESPERIA is an equatorial space mission mainly concerned with detecting any tectonic and preseismic related signals. More in general, it has been proposed for defining the near-Earth electromagnetic, plasma, and particle environment, and for studying perturbations and instabilities in the ionosphere-magnetosphere transition region. To study earthquake preparation processes and anthropogenic impacts in the Earth's surface, a phase A study has been realized for the Italian Space Agency.

Climate change, rising atmospheric carbon dioxide, excess nutrients, and pollution in many forms are altering global oceanic geochemistry. Rates of change for some aspects greatly exceed those in the historical and recent geological record. Major trends include an increasing acidity, reduced subsurface oxygen in both near-shore and pelagic waters, rising coastal nitrogen levels, and widespread increases in mercury and persistent organic pollutants. Most of these perturbations are tied either directly or indirectly to human fossil fuel combustion, fertilizer, and industrial activity.

Because of conservation of angular momentum, such changes of inertia result in small changes to the Earth's rate of rotation. These are expected changes for an earthquake of this magnitude. The earthquake also generated infrasound waves detected by perturbations in the orbit of the GOCE satellite, which thus serendipitously became the first seismograph in orbit. Soil liquefaction was evident in areas of reclaimed land around Tokyo, particularly in Urayasu,Fukue, Natsuko, "Liquefaction driving away Chiba residents", Japan Times, 30 March 2012, p. 3.

The "late-time" ISW effect arises quite recently in cosmic history, as dark energy, or the cosmological constant, starts to govern the Universe's expansion. Unfortunately, the nomenclature is a bit confusing. Often, "late-time ISW" implicitly refers to the late-time ISW effect to linear/first order in density perturbations. This linear part of the effect entirely vanishes in a flat universe with only matter, but dominates over the higher-order part of the effect in a universe with dark energy.

Pelagic mesocosm experiments that examined the response of natural plankton communities to controlled pH perturbations helped move methods of ocean acidification research toward more comprehensive studies of whole communities and embedded processes under mostly natural conditions.Riebesell U., Czerny J., von Bröckel K., Boxhammer T., Büdenbender J., Deckelnick M., Fischer M., Hoffmann D., Krug S. A., Lentz U., Ludwig A., Muche R. & Schulz K. G., 2013. Technical Note: A mobile sea-going mesocosm system – new opportunities for ocean change research. Biogeosciences 10:1835–1847.

Genetic engineering has potential applications in conservation and natural area management. Gene transfer through viral vectors has been proposed as a means of controlling invasive species as well as vaccinating threatened fauna from disease. Transgenic trees have been suggested as a way to confer resistance to pathogens in wild populations. With the increasing risks of maladaptation in organisms as a result of climate change and other perturbations, facilitated adaptation through gene tweaking could be one solution to reducing extinction risks.

Like Münster, Partington also refers to the mixture of oxygen and hydrogen. He adds a proviso that "In a true equilibrium state, the smallest change of any external condition which influences the state will produce a small change of state ..."Partington, J.R. (1949), p. 161. This proviso means that thermodynamic equilibrium must be stable against small perturbations; this requirement is essential for the strict meaning of thermodynamic equilibrium. A student textbook by F.H. Crawford has a section headed "Thermodynamic Equilibrium".

A debris cloud resulting from a single event is studied with scatter plots known as Gabbard diagrams, where the perigee and apogee of fragments are plotted with respect to their orbital period. Gabbard diagrams of the early debris cloud prior to the effects of perturbations, if the data were available, are reconstructed. They often include data on newly observed, as yet uncatalogued fragments. Gabbard diagrams can provide important insights into the features of the fragmentation, the direction and point of impact.

Orbits are affected by gravitational perturbations (which in LEO include unevenness of the Earth's gravitational field due to variations in the density of the planet), and collisions can occur from any direction. Impacts between orbiting satellites can occur at up to 16 km/s for a theoretical head-on impact; the closing speed could be twice the orbital speed. The 2009 satellite collision occurred at a closing speed of 11.7 km/s,"What are hypervelocity impacts?" ESA, 19 February 2009.

It introduced the famous definition for sustainable development: Of a different kind is the approach made by James Lovelock. In the 1970s he and microbiologist Lynn Margulis presented the Gaia theory or hypothesis, that states that all organisms and their inorganic surroundings on Earth are integrated into a single self-regulating system.; . The system has the ability to react to perturbations or deviations, much like a living organism adjusts its regulation mechanisms to accommodate environmental changes such as temperature (homeostasis).

Impacts on primary production would affect the carbon cycle, leading to a reduction in atmospheric carbon dioxide. A reduction in atmospheric carbon dioxide would result in a negative feedback, or cooling, of the climate system. Model results indicated that, for the most part, the lightning-biota climatic feedback retarded positive perturbations in atmospheric carbon dioxide and temperature back to an "equilibrium" state. Impacts of the lightning-biota climatic feedback on curbing anthropogenic influences on atmospheric carbon dioxide concentrations were investigated as well.

In the absence of seismic data, the measurements of the tidal deformation and proper motion of the planet provide the way to probe its deep internal structure (size and state of the core). The tidal deformation can be measured in the EnVision orbital velocity perturbations through the gravitational potential variations it generates (k2 tidal Love number). The co-Principal Investigators of EnVision Radio Science and Gravity experiment are Caroline Dumoulin, LPG, Université de Nantes, France, and Pascal Rosenblatt, LPG, Université de Nantes, France.

If the current vacuum state is a false vacuum, the vacuum may decay into a lower-energy state.Adams & Laughlin (1997), §VE. Presumably, extreme low-energy states imply that localized quantum events become major macroscopic phenomena rather than negligible microscopic events because the smallest perturbations make the biggest difference in this era, so there is no telling what may happen to space or time. It is perceived that the laws of "macro-physics" will break down, and the laws of quantum physics will prevail.

In December 2013, perturbations of the orbital motions in the system were reported, suggesting a third body in the system. The period of this possible companion was a few months, suggesting an orbit around one of the brown dwarfs. Any companion would need to be below the brown-dwarf mass limit, because it would otherwise have been detected through direct imaging. They estimated the odds of a false positive as 0.002%, assuming the measurements had not been made in error.

The Blanowice Formation recovers a deltaic section on the eastern Bohemian Massif, where rivers come from the west, as proven by the Carboniferous fossil matter found on the layers of the formation, moved from the west of the Czech Republic, and deposited especially on the Parkoszowice borehole.Ruebsam, W., Pieńkowski, G., & Schwark, L. (2020). Toarcian climate and carbon cycle perturbations–its impact on sea-level changes, enhanced mobilization and oxidation of fossil organic matter. Earth and Planetary Science Letters, 546, 116417.

As with the idealized environment, crosswise vorticity lines are tilted into the vertical on the flanks of this updraft. Once the pressure perturbations initiate new updrafts on the flanks and they begin to rotate as a result of stretching and ingestion of newly experienced streamwise vorticity. The right split, having propagated even farther right to the hodograph, has increased the magnitude of positive SRH ingestion. This will serve to increase the rotation in the updraft, intensifying the pressure perturbation, strengthening the storm.

The Encke program was used when the vehicle was within 125 earth radii and the Interplanetary program, adjusting for planetary perturbations, for vehicles beyond that distance. The Special Project Analysts also handled special requests for such things as very accurate orbital elements or decay information for a satellite (as might be required by research or educational groups). These analysts also monitored incoming technical papers, attended technical meetings to obtain information which was of use to the mission, and monitored improvements in decay forecasts.

It is then compared to the computed tomographic fan- beam measurement of the absorbing perturbations in the slice. These perturbation data are then reconstructed into slice images using a highly modified proprietary filtered back-projection algorithm that converts the fan- beam data into sinographics. It also corrects for geometric distortions due to bulk light-tissue interaction, and compensates for a spatially variant blurring effect that is typical of diffuse optical imaging. 3D images visualization is available immediately after data acquisition.

The system was operational by 1967, with the construction of the Orbita groundstations. They had a lifespan of approximately 1.5 years, as their orbits were disrupted by perturbations, as well as deteriorating solar arrays and they had to be constantly replaced. By the 1970s, the Molniya 1 series (and the upgrade Molniya 1T) was mostly used for military communications, with civilian communications moving to Molniya 2. In total 94 Molniya 1 series satellites were launched, with the last going up in 2004.

Such small asteroids then become subject to perturbations such as the Yarkovsky effect that can push them towards orbital resonances with Jupiter over time. Once there, they are relatively rapidly ejected from the asteroid belt. Tentative age estimates have been obtained for some families, ranging from hundreds of millions of years to less than several million years as for the compact Karin family. Old families are thought to contain few small members, and this is the basis of the age determinations.

An analysis in 2016 of Pluto's orbit by Holman and Payne found perturbations much larger than predicted by Batygin and Brown's proposed orbit for Planet Nine. Holman and Payne suggested three possible explanations: systematic errors in the measurements of Pluto's orbit; an unmodeled mass in the Solar System, such as a small planet in the range of 60– (potentially explaining the Kuiper cliff); or a planet more massive or closer to the Sun instead of the planet predicted by Batygin and Brown.

In 2016, a team of astronomers reported the detection of a pair of giant planetary companions. Radial velocity measurements indicated gravitational perturbations of the star being caused by orbiting objects. The best fit to the preliminary data suggests two periodicities: one almost exactly a year long like the Earth's periodicity, and a second of around two years. Both objects are predicted to have masses greater than that of the planet Jupiter: their minimum masses are 1.8 and 1.9 Jupiter masses, respectively.

The oscillator itself controls the phase with which the external power acts on it. Self- oscillators are therefore distinct from forced and parametric resonators, in which the power that sustains the motion must be modulated externally. In linear systems, self-oscillation appears as an instability associated with a negative damping term, which causes small perturbations to grow exponentially in amplitude. This negative damping is due to a positive feedback between the oscillation and the modulation of the external source of power.

November to March have the highest mean wind speeds, while June to August have the lightest winds. The predominant wind direction is from the southwest. During December 2013, several deep areas of low pressure moved across or to the north of the British Isles, bringing high wind speeds and heavy rain to many locations. This weather was connected to major perturbations to the Pacific and North Atlantic jet streams, which was partially caused by persistent rainfall over Indonesia and the tropical Pacific Ocean.

Pressure perturbations around thunderstorms are noteworthy. With buoyancy rapid within the lower and mid-levels of a mature thunderstorm, updraft and downdraft create distinct mesocenters of pressure. As thunderstorms organized in squall lines, the northern end of the squall line is commonly referred to as the cyclonic end, with the southern side rotating anticyclonically (in Northern hemisphere). Because of the coriolis force, the northern end may evolve further, creating a "comma shaped" wake low, or may continue in a squall-like pattern.

If the perturbation to the oscillatory cycle is infinitesimally small, it is possible to derive a response function of the neural oscillator. This response function can be classified into different classes (Type 1 and Type 2) based upon its response. #Type I Phase Response Curves are non-negative and strictly positive thus perturbations are only able to enhance a spike in phase, but never delay it. This occurs through a slight depolarization, such as postsynaptic potentials that increase the excitation of an axon.

The BiFC system has been applied to record ribosome biogenesis events in E.coli. The process of ribosomes assembly involves nucleation of ribosomal proteins in proper order and orientation. Perturbations in assembly can lead to structural defects in ribosomal subunits which as a result cannot join in the correct orientation to form fully functional ribosomes. Thus, the events of subunit joining signaled by the appearance of BiFC is an easy way to monitor ribosome biogenesis in contrast to laborious polysome profiling methods.

Disco is a discontinued application for Mac OS X developed by Austin Sarner, Jasper Hauser and Jason Harris. The software is an optical disc authoring utility, which allows users to burn CDs and DVDs with multisession support, disc duplication, burning VIDEO_TS folders, disc spanning as well as a searchable disc index, dubbed Discography. Disco also features an interactive "3D smoke" animation which is visible when burning. This smoke responds to microphone input, as well as mouse input, causing perturbations in the smoke effect.

Tuberous receptors are electroreceptors that are specialized to respond to high-frequency electrical fields (electric organ discharges or EODs), and hence are found only in fish with an active electrical sense that can generate their own electrical fields. They are mostly found on weakly electric fishes such as gymnotiforms and mormyrids. These receptors are particularly receptive to their own electrical fields, and can detect perturbations caused by foreign objects. There are two types of tuberous receptors, t-type and p-type.

It can also be used to model specific GRNs and systems of chemical reactions. Genetic perturbations such as gene deletions, gene over-expression, insertions, frame shift mutations can also be modeled as well. The GRN is created from a graph with the desired topology, imposing in-degree and out- degree distributions. Gene promoter activities are affected by other genes expression products that act as inputs, in the form of monomers or combined into multimers and set as direct or indirect.

Root locus plot of Wien bridge oscillator pole positions for R1 = R2 = 1 and C1 = C2 =1 versus K = (Rb \+ Rf)/Rb. The numerical values of K are shown in a purple font. The trajectory of the poles for K=3 is perpendicular to the imaginary (β) axis. For K >> 5, one pole approaches the origin and the other approaches K. Small perturbations in the value of Rb cause the dominant poles to move back and forth across the jω (imaginary) axis.

A restricted LoS significantly influences the ability to react to perturbations in balance control testing. This reduction in LoS may be because of weakness of the ankle and foot muscles, musculoskeletal problems of the lower limb, and/or an internal perception of the subject to resist larger displacements.NeuroCom® Clinical Integration Lab Manual.pdf These impairments may help physicians to correlate with the medical examination findings and serve as an important outcome measure for rehabilitation of these specific underlying body impairments.

If, like the Earth, a body generates a magnetic field, it will also possess magnetic poles. Perturbations in a body's rotation mean that geographical poles wander slightly on its surface. The Earth's North and South Poles, for example, move by a few metres over periods of a few years. As cartography requires exact and unchanging coordinates, the averaged locations of geographical poles are taken as fixed cartographic poles and become the points where the body's great circles of longitude intersect.

Another case where the effective two-state formalism is valid is when the system under consideration has two levels that are effectively decoupled from the system. This is the case in the analysis of the spontaneous or stimulated emission of light by atoms and that of charge qubits. In this case it should be kept in mind that the perturbations (interactions with an external field) are in the right range and do not cause transitions to states other than the ones of interest.

Apsidal precession—the orbit rotates gradually over time. The orbits of planets around the Sun do not really follow an identical ellipse each time, but actually trace out a flower-petal shape because the major axis of each planet's elliptical orbit also precesses within its orbital plane, partly in response to perturbations in the form of the changing gravitational forces exerted by other planets. This is called perihelion precession or apsidal precession. In the adjunct image, Earth's apsidal precession is illustrated.

Obliquity of the ecliptic is the term used by astronomers for the inclination of Earth's equator with respect to the ecliptic, or of Earth's rotation axis to a perpendicular to the ecliptic. It is about 23.4° and is currently decreasing 0.013 degrees (47 arcseconds) per hundred years because of planetary perturbations. , art. 365–367, p. 694–695, at Google books The angular value of the obliquity is found by observation of the motions of Earth and other planets over many years.

Negative feedback tends to promote a settling to equilibrium, and reduces the effects of perturbations. Negative feedback loops in which just the right amount of correction is applied with optimum timing can be very stable, accurate, and responsive. Negative feedback is widely used in mechanical and electronic engineering, and also within living organisms, and can be seen in many other fields from chemistry and economics to physical systems such as the climate. General negative feedback systems are studied in control systems engineering.

Electronics circuits and devices second edition. Ralph J. Smith In that case, it can be shown that the overall or "closed loop" gain from input to output is: :G_c = A/(1-AB) When AB > 1, the system is unstable, so does not have a well-defined gain; the gain may be called infinite. Thus depending on the feedback, state changes can be convergent, or divergent. The result of positive feedback is to augment changes, so that small perturbations may result in big changes.

Coupled social-ecological systems are constantly changing in ways that cannot be fully predicted or controlled. Understanding the resilience of ecosystems, i.e. the extent to which they can maintain structure, function, and identity in the face of disturbance, can enable better prediction of how ecosystems will respond to both natural and anthropogenic perturbations, and to changes in environmental management. With how much modification humans are doing to environments, it is important to understand these changes on a yearly basis as well.

Perturbations and interference from the earth's atmosphere make space-based observations necessary for infrared, ultraviolet, gamma-ray, and X-ray astronomy. Physical cosmology is the study of the formation and evolution of the universe on its largest scales. Albert Einstein's theory of relativity plays a central role in all modern cosmological theories. In the early 20th century, Hubble's discovery that the universe is expanding, as shown by the Hubble diagram, prompted rival explanations known as the steady state universe and the Big Bang.

In physics, SDEs have widest applicability ranging from molecular dynamics to neurodynamics and to the dynamics of astrophysical objects. More specifically, SDEs describe all dynamical systems, in which quantum effects are either unimportant or can be taken into account as perturbations. SDEs can be viewed as a generalization of the dynamical systems theory to models with noise. This is an important generalization because real systems cannot be completely isolated from their environments and for this reason always experience external stochastic influence.

He and his colleagues (Edward Ott and James A. Yorke) have shown with a numerical example that one can convert a chaotic attractor to any one of numerous possible attracting time-periodic motions by making only small time-dependent perturbations of an available system parameter. This article is considered as one among the classic works in the control theory of chaos and their control method is known as the famous O.G.Y. method. He was listed in the 2016 Thomson Reuters Citation Laureates.

In the Solar System, this is usually the case; Jupiter, the second largest body, has a mass of about 1/1000 that of the Sun. General perturbation methods are preferred for some types of problems, as the source of certain observed motions are readily found. This is not necessarily so for special perturbations; the motions would be predicted with similar accuracy, but no information on the configurations of the perturbing bodies (for instance, an orbital resonance) which caused them would be available.

These are always present, no matter how smooth the stream is. If the perturbations are resolved into sinusoidal components, we find that some components grow with time while others decay with time. Among those that grow with time, some grow at faster rates than others. Whether a component decays or grows, and how fast it grows is entirely a function of its wave number (a measure of how many peaks and troughs per centimeter) and the radii of the original cylindrical stream.

A primordial isocurvature baryon model (PIB model) is a theoretical model describing the development of the early universe. It may be contrasted with the cold dark matter model (CDM model). The PIB model was proposed in 1987 by Jim Peebles as an alternative to the CDM model, which does not necessitate the existence of exotic dark matter.Hu (1994-06-28) PIB models, which ascribe all cosmic density perturbations to isocurvature modes, predict results that are inconsistent with the observational data.

As such they are of generally stony (rather than icy) surface composition that includes silicates and some nickel-iron, and are quite bright for their size. The family contains relatively large numbers of small objects. Since most of these smaller objects are "eroded" away over time due to secondary collisions, gravitational perturbations, and the Yarkovsky effect, this indicates that the Eunomia family was created relatively recently (on an astronomical timescale). The Cassini-Huygens spacecraft flew by 2685 Masursky, a small family member, in 2000.

The results obtained by Montzka et al. (2011) shows that the interannual variability in •OH estimated from CH3CCl3 measurements is small, indicating that global •OH is generally well buffered against perturbations. This small variability is consistent with measurements of methane and other trace gases primarily oxidized by •OH, as well as global photochemical model calculations. In 2014, researchers reported their discovery of a "hole" or absence of hydroxyl throughout the entire depth of the troposphere across a large region of the tropical West Pacific.

ELVES (Emission of Light and Very Low Frequency perturbations due to Electromagnetic Pulse Sources) often appear as a dim, flattened, expanding glow around in diameter that lasts for, typically, just one millisecond.ELVES, a primer: Ionospheric Heating By the Electromagnetic Pulses from Lightning They occur in the ionosphere above the ground over thunderstorms. Their color was a puzzle for some time, but is now believed to be a red hue. ELVES were first recorded on another shuttle mission, this time recorded off French Guiana on October 7, 1990.

If it were possible to run the model for every possible set of initial conditions, each with an associated probability, then according to how many members (i.e., individual model runs) of the ensemble predict a certain event, one could compute the actual conditional probability of the given event. In practice, forecasters try to guess a small number of perturbations (usually around 20) that they deem are most likely to yield distinct weather outcomes. Two common techniques for this purpose are breeding vectors (BV) and singular vectors (SV).

Fernández Escudero 2012, p. 394 Whether he was indeed remains unclear; though he contributed to military buildup and harbored political hopes related to potentially rebellious Spanish generals,Consuelo Sanz-Pastor y Fernandez de Pierola, El marqués de Cerralbo, politico carlista, [in:] Revista de archivos bibliotecas y museos 76 (1978), p. 259 scholars tend to assume that the rebels acted on their own and with no official order, if not clearly against it. Some partisan versions claimed that the affair was aimed at causing Madrid stock exchange perturbations.

On 17 March 1958, the three-stage launch vehicle placed Vanguard into a 654 x 3969 kilometers, 134.2 minute elliptical orbit inclined at 34.25°. Original estimates had the orbit lasting for 2,000 years, but it was discovered that solar radiation pressure and atmospheric drag during high levels of solar activity produced significant perturbations in the perigee height of the satellite, which caused a significant decrease in its expected lifetime to about 240 years. Vanguard 1 transmitted its signals for nearly seven years as it orbited the Earth.

Metamorphic belts are a consequence of thermal perturbations, due to low temperature with respect to pressure ratios (dT/dP) in oceanic trenches and high temperature with respect to pressure ratios (dT/dP) in arcs. Paired metamorphic belts are the product of subducted colder crustal rocks, which are taken to depth, metamorphosed and then exhumed. However, if the rock unit is not exhumed relatively quickly after subduction ceases, the rock unit will re-equilibrate to the standard geothermal gradient and the geological record will be lost.

Studies of motor behavior focus on the adaptive and feedback properties of the nervous system in motor control. The motor system has been shown to adapt to changes in its mechanical environment on relatively short timescales while simultaneously producing smooth movements; these studies investigate how this remarkable feedback takes place. Such studies investigate which variables the nervous system controls, which variables are less tightly controlled, and how this control is implemented. Common paradigms of study include voluntary reaching tasks and perturbations of standing balance in humans.

In his thesis, Haret proved by using third degree approximations that the axes are not stable as previously believed, but instead feature a time variability, which he called secular perturbations. This result implies that planetary motion is not absolutely stable. Henri Poincaré considered this result a great surprise and continued Haret’s research, which eventually led him to the creation of chaos theory. Félix Tisserand recommended the extension of Haret's method to other astronomic problems and, much later, in 1955, Jean Meffroy restarted Haret’s research using new techniques.

The values are obtained from Chenciner & Montgomery (2000). In 1993, a zero angular momentum solution with three equal masses moving around a figure-eight shape was discovered numerically by physicist Cris Moore at the Santa Fe Institute. Its formal existence was later proved in 2000 by mathematicians Alain Chenciner and Richard Montgomery. The solution has been shown numerically to be stable for small perturbations of the mass and orbital parameters, which raises the intriguing possibility that such orbits could be observed in the physical universe.

Like the majority of long-period extrasolar planets, the orbit of Upsilon Andromedae c is eccentric, more so than any of the major planets in the Solar System (including Pluto). (web version) If placed in the Solar System, Upsilon Andromedae c would lie between the orbits of Earth and Venus. The high orbital eccentricity may be the result of gravitational perturbations from the planet Upsilon Andromedae d. Simulations suggest that the orbit of Upsilon Andromedae c returns to its original circular state roughly once every 9,000 years.

The Planet V hypothesis posits that a fifth terrestrial planet created the Late Heavy Bombardment when its meta-stable orbit entered the inner asteroid belt. The hypothetical fifth terrestrial planet, Planet V, had a mass less than half of Mars and originally orbited between Mars and the asteroid belt. Planet V's orbit became unstable due to perturbations from the other inner planets causing it to intersect the inner asteroid belt. After close encounters with Planet V, many asteroids entered Earth-crossing orbits producing the Late Heavy Bombardment.

Polymorphisms of the ADCY2 gene have been associated with COPD and lung function. Perturbations in adenylyl cyclase activity have been implicated in alcohol and opioid addiction and is associated with human diseases, including thyroid adenoma, Anthrax, precocious puberty in males and chondrodysplasia punctata diseases. During these diseases, ADCY2 undergoes a super-related pathway where protein kinase A (PKA) activation occurs in glucagon signaling and IP3 signaling. This enzyme may play a role in bipolar disorder along with other brain-expressed genes including NCALD, WDR60, SCN7A, and SPAG16.

Applying this technology to the characterization and discovery of regulatory variant alleles, Vockley et al. characterized the effects of human genetic variation on non-coding regulatory element function, measuring the activity of 100 putative enhancers captured directly from the genomes of 95 members of a study cohort. This approach enables the functional fine-mapping of causal regulatory variants in regions of high linkage disequilibrium identified by eQTL analyses. This approach provides a general path forward to identify perturbations in gene regulatory elements that contribute to complex phenotypes.

It is well known that perturbations of these activating factors can lead to unregulated TGF-β signaling levels that may cause several complications including inflammation, autoimmune disorders, fibrosis, cancer and cataracts. In most cases an activated TGF-β ligand will initiate the TGF-β signaling cascade as long as TGF-β receptors I and II are within reach, this is due to high affinity between TGF-β and its receptors, suggesting why the TGF-β signaling recruits a latency system to mediates its signaling.

Multiple views of 16 Psyche imaged by the Very Large Telescope Psyche is massive enough that its gravitational perturbations on other asteroids can be observed, which enables a mass measurement. The values for the mass of () and the density of obtained from a 2002 analysis by Kuzmanoski and Kovačević, of a close encounter with asteroid . The new, high density estimate suggests that 16 Psyche must be composed mostly of metals. As of 2019, the best mass estimate is , with a derived bulk density of .

A similar experiment was performed on the cricket (Acheta domestica), an arthropod like the crayfish. The cercal system in the cricket senses the displacement of particles due to air currents utilizing filiform hairs covering the cerci, the two antenna-like appendages extending from the posterior section of the abdomen. Sensory interneurons in terminal abdominal ganglion carry information about intensity and direction of pressure perturbations. Crickets were presented with signal plus noise stimuli and the spikes from cercal interneurons due to this input were recorded.

His work on the Newtonian limit, particularly in relation to cosmological solutions, led Ehlers, together with his former doctoral student Thomas Buchert, to a systematic study of perturbations and inhomogeneities in a Newtonian cosmos. This laid the groundwork for Buchert's later generalization of this treatment of inhomogeneities. This generalization was the basis of his attempt to explain what is currently seen as the cosmic effects of a cosmological constant or, in modern parlance, dark energy, as a non-linear consequence of inhomogeneities in general-relativistic cosmology.See , and .

If the perturbations are resolved into sinusoidal components, we find that some components grow with time, while others decay with time. Among those that grow with time, some grow at faster rates than others. Whether a component decays or grows, and how fast it grows is entirely a function of its wave number (a measure of how many peaks and troughs per unit length) and the radius of the original cylindrical stream. The diagram to the right shows an exaggeration of a single component.

The brighter component, ζ Aquarii A (also called ζ2 Aquarii), is a yellow-white-hued F-type main sequence star with an apparent magnitude of +4.42. Its companion, ζ Aquarii B (also called ζ1 Aquarii), is a yellow-white-hued F-type subgiant with an apparent magnitude of +4.51. The fact that their brightness is so similar makes the pair easy to measure and resolve. Zeta Aquarii A is known to be an astrometric binary system, as it undergoes regular perturbations from its orbit.

Marionnet design. On top of a GNU/Linux host, the emulation of guest machines is achieved through User Mode Linux technology that allows to run many Linux kernels in user space as regular processes. VDE - Virtual Distributed Ethernet project is responsible of linking together Uml machines in a virtual network, its purpose is to emulate cable, hub and switch devices allowing also to introduce perturbations in the communication. On top of this raw emulated network Marionnet acts as a coherent manager and as a GUI.

An advantage of surface-immobilized experiments is that many molecules can be observed in parallel for an extended period of time until photobleaching (typically 1-30 s). This allows to conveniently study transitions taking place on slow time scales. A disadvantage is represented by the additional biochemical modifications needed to link molecules to the surface and the perturbations that the surface can potentially exert on the molecular activity. In addition, the maximum time resolution of single- molecule intensities is limited by the camera acquisition time (> 1 ms).

Astronomers have a number of observational tools that they can use to make measurements of the heavens. For objects that are relatively close to the Sun and Earth, direct and very precise position measurements can be made against a more distant (and thereby nearly stationary) background. Early observations of this nature were used to develop very precise orbital models of the various planets, and to determine their respective masses and gravitational perturbations. Such measurements led to the discovery of the planets Uranus, Neptune, and (indirectly) Pluto.

Potentiodynamic techniques also exist that add low-amplitude AC perturbations to a potential ramp and measure variable response in a single frequency (AC voltammetry) or in many frequencies simultaneously (potentiodynamic electrochemical impedance spectroscopy). The response in alternating current is two-dimensional, characterized by both amplitude and phase. These data can be analyzed to determine information about different chemical processes (charge transfer, diffusion, double layer charging, etc.). Frequency response analysis enables simultaneous monitoring of the various processes that contribute to the potentiodynamic AC response of an electrochemical system.

Alpert called it "a nonsensically unconventional movie" where viewers "would be better off not trying to make sense or logic out of it, but simply allowing M. Renoir to have his day in the fields". Bachmann wrote that the film is reminiscent of Tati's films, both in message and how the message is conveyed through colors. He contrasted the seeming simplicity with the serious content, and the impressionism with the surreal elements. He called it "almost facile in impact but lasting in the perturbations it causes".

The majority of known asteroids orbit within the asteroid belt between the orbits of Mars and Jupiter, generally in relatively low-eccentricity (i.e. not very elongated) orbits. This belt is now estimated to contain between 1.1 and 1.9 million asteroids larger than in diameter, and millions of smaller ones. These asteroids may be remnants of the protoplanetary disk, and in this region the accretion of planetesimals into planets during the formative period of the Solar System was prevented by large gravitational perturbations by Jupiter.

The temperature variation in the CMB temperature maps at higher multipoles, or ℓ ≥ 2, is considered to be the result of perturbations of the density in the early Universe, before the recombination epoch. Before recombination, the Universe consisted of a hot, dense plasma of electrons and baryons. In such a hot dense environment, electrons and protons could not form any neutral atoms. The baryons in such early Universe remained highly ionized and so were tightly coupled with photons through the effect of Thompson scattering.

Farnham: Gregg International Publishers could not accept that Ekoid formed part of Bantu. His first improbable explanation was that its ‘Bantuisms’ resulted from speakers of a Bantu language being ‘absorbed’ by those who spoke a ‘Western Sudanic’ language, in other words, the apparent parallels, were simply a massive block of loanwords. This was later modified into ‘Ekoid languages may to some extent share an origin with some of the A zone languages, but they seem to have undergone considerable perturbations’ (Guthrie 1971, II:15).

Lunar orbital effects principally resulting from the strong gravitational perturbations of the mascons were ultimately revealed as the cause. William Wollenhaupt and Emil Schiesser of the NASA Manned Spacecraft Center in Houston then worked out the "fix" that was first applied to Apollo 12 and permitted its landing within 163 m (535 ft) of the target, the previously-landed Surveyor 3 spacecraft. In May 2013 a NASA study was published with results from the twin GRAIL probes, that mapped mass concentrations on Earth's Moon.

Unperturbed, two-body, Newtonian orbits are always conic sections, so the Keplerian elements define an ellipse, parabola, or hyperbola. Real orbits have perturbations, so a given set of Keplerian elements accurately describes an orbit only at the epoch. Evolution of the orbital elements takes place due to the gravitational pull of bodies other than the primary, the nonsphericity of the primary, atmospheric drag, relativistic effects, radiation pressure, electromagnetic forces, and so on. Keplerian elements can often be used to produce useful predictions at times near the epoch.

However, perturbation expansions are generally not reliable for questions of long-term existence and stability, in the case of nonlinear equations. The full field equation is highly nonlinear, so we really want to prove that the Minkowski vacuum is stable under small perturbations which are treated using the fully nonlinear field equation. This requires the introduction of many new ideas. The desired result, sometimes expressed by the slogan that the Minkowski vacuum is nonlinearly stable, was finally proven by Demetrios Christodoulou and Sergiu Klainerman only in 1993.

The unproven 'AdS instability conjecture' introduced by the physicists Piotr Bizon and Andrzej Rostworowski in 2011 states that arbitrarily small perturbations of certain shapes in AdS lead to the formation of black holes. Mathematician Georgios Moschidis proved that given spherical symmetry, the conjecture holds true for the specific cases of the Einstein-null dust system with an internal mirror (2017) and the Einstein-massless Vlasov system (2018).Moschidis, Georgios. "A proof of the instability of AdS for the Einstein--massless Vlasov system." arXiv preprint arXiv:1812.04268 (2018).

More-complex patterns with more rings would intercept more of the star's output, but would result in some constructs eclipsing others periodically when their orbits overlap. Another potential problem is that the increasing loss of orbital stability when adding more elements increases the probability of orbital perturbations. Such a cloud of collectors would alter the light emitted by the star system (see below). However, the disruption compared to a star's overall natural emitted spectrum would most likely be too small for Earth-based astronomers to observe.

The effects of other gravitating bodies can be significant. For example, the orbit of the Moon cannot be accurately described without allowing for the action of the Sun's gravity as well as the Earth's. One approximate result is that bodies will usually have reasonably stable orbits around a heavier planet or moon, in spite of these perturbations, provided they are orbiting well within the heavier body's Hill sphere. When there are more than two gravitating bodies it is referred to as an n-body problem.

The cluster is made up out of 150 stars with magnitude from 9 to 15 within a tidal radius of 9 parsec (30 light years). From its members, 3 are probably delta Scuti variables. One other member of the cluster is the variable SS Lancertae, a binary star with 14.4 day period whose magnitude stopped varying in the middle of the 20th century. This has been attributed to the presence of a third star with period 679 days, whose perturbations change the line of sight.

For a typical cluster with 1,000 stars with a 0.5 parsec half-mass radius, on average a star will have an encounter with another member every 10 million years. The rate is even higher in denser clusters. These encounters can have a significant impact on the extended circumstellar disks of material that surround many young stars. Tidal perturbations of large disks may result in the formation of massive planets and brown dwarfs, producing companions at distances of 100 AU or more from the host star.

A perihelion date of 1939-08-09 was indicated. Based on these early orbits, Leland E. Cunningham of the Harvard College Observatory suggested that the comet was likely identical with Herschel's comet of 1788. The final calculation of the orbit, by Brian G. Marsden in 1974, used 75 positions from both apparitions of the comet in 1788 and 1939–40 in addition to perturbations by planets, and linked the two sightings, with a perihelion date of 1939-08-09 and a period of 155 years.

The exponential mechanism is a technique for designing differentially private algorithms. It was developed by Frank McSherryFrank McSherry and Kunal TalwarKunal Talwar in 2007. Their work was recognized as a co-winner of the 2009 PET Award for Outstanding Research in Privacy Enhancing Technologies. Most of the initial research in the field of differential privacy revolved around real-valued functions which have relatively low sensitivity to change in the data of a single individual and whose usefulness is not hampered by small additive perturbations.

Some scientists have investigated possible neurocognitive processes underlying the formation of paranormal beliefs. In a study (Pizzagalli et al. 2000) data demonstrated that "subjects differing in their declared belief in and experience with paranormal phenomena as well as in their schizotypal ideation, as determined by a standardized instrument, displayed differential brain electric activity during resting periods." Another study (Schulter and Papousek, 2008) wrote that paranormal belief can be explained by patterns of functional hemispheric asymmetry that may be related to perturbations during fetal development.

With this electrophysiological approach, proteoliposomes, membrane vesicles, or membrane fragments containing the channel or transporter of interest are adsorbed to a lipid monolayer painted over a functionalized electrode. This electrode consists of a glass support, a chromium layer, a gold layer, and an octadecyl mercaptane monolayer. Because the painted membrane is supported by the electrode, it is called a solid-supported membrane. It is important to note that mechanical perturbations, which usually destroy a biological lipid membrane, do not influence the life-time of an SSM.

There is an old record from the Nolin River system, where the species no longer occurs. The frecklebelly darter as well as most other darter species in the area are vulnerable to decimation through perturbations such as strip mining; stream channelization projects threaten available habitat in Tennessee. It is believed that these factors as well as the damming of natural river systems may have extirpated the species from other areas in the southeast. Non-native Invasive fish species could also be a cause of limited distribution.

Tomographic reconstruction creates three-dimensional views of an object by combining two-dimensional images taken from multiple directions, for example in how a computer-aided tomography scanner allows 3D views of the heart or brain. Data collection can be rapid, but the required computations are massive. Further, many common experimental perturbations can degrade the quality of tomographs, unless corrections are applied. Unless automated tools make these corrections, beamline staff can be overwhelmed by data that can be collected far faster than corrections and reconstruction can be performed.

A wide variety of biochemical, physiological and cytological perturbations has been identified following the exposure of cells and animals to such species, independently of their identity. The oligomers have also been reported to interact with a variety of molecular targets. Hence, it is unlikely that there is a unique mechanism of toxicity or a unique cascade of cellular events. The misfolded nature of protein aggregates causes a multitude of aberrant interactions with a multitude of cellular components, including membranes, protein receptors, soluble proteins, RNAs, small metabolites, etc.

If all goes according to plan, the new attractor encourages the system to continue on the desired trajectory. One strength of this method is that it does not require a detailed model of the chaotic system but only some information about the Poincaré section. It is for this reason that the method has been so successful in controlling a wide variety of chaotic systems. The weaknesses of this method are in isolating the Poincaré section and in calculating the precise perturbations necessary to attain stability.

Limitation of Size plus I being a set (hence the universe is nonempty) renders provable the sethood of the empty set; hence no need for an axiom of empty set. Such an axiom could be added, of course, and minor perturbations of the above axioms would necessitate this addition. The set I is not identified with the limit ordinal \omega, as I could be a set larger than \omega. In this case, the existence of \omega would follow from either form of Limitation of Size.

These two basins are connected by the Mariana and Yap trenches separated by a sill deep. Water above this depth can reach the West Caroline Basin without perturbations and temperature and salinity profiles for the two basins are similar. This trench, the only conduit for bottom waters in the West Caroline Basin, ventilates the basin. The North Equatorial Current flows westward across the West Caroline Basin between 25°N and 5°N around 170-180°E in February but lies below 10°N in August.

Saccharomyces cerevisiae contains six B-type cyclins (Clb1-6), with Clb2 being the most essential for function. In both vertebrates and S. cerevisiae, it is speculated that the presence of multiple B-type cyclins allows different cyclins to regulate different portions of the G2/M transition while also making the transition robust to perturbations. Subsequent discussions will focus on the spatial and temporal activation of cyclin B1/CDK in mammalian cells, but similar pathways are applicable in both other metazoans and in S. cerevisiae.

Hu, Sugiyama & Silk (1996-04-28), p. 2 The strength of diffusion damping is calculated by a mathematical expression for the damping factor, which figures into the Boltzmann equation, an equation which describes the amplitude of perturbations in the CMB. The strength of the diffusion damping is chiefly governed by the distance photons travel before being scattered (diffusion length). The primary effects on the diffusion length are from the properties of the plasma in question: different sorts of plasma may experience different sorts of diffusion damping.

Le Chatelier's principle refers to states of thermodynamic equilibrium. The latter are stable against perturbations that satisfy certain criteria; this is essential to the definition of thermodynamic equilibrium. For this, a state of thermodynamic equilibrium is most conveniently described through a fundamental relation that specifies a cardinal function of state, of the energy kind, or of the entropy kind, as a function of state variables chosen to fit the thermodynamic operations through which a perturbation is to be applied.Münster, A. (1970), pp. 173–174.

Breakup of an elongated stream of water into droplets due to surface tension. In day-to-day life all of us observe that a stream of water emerging from a faucet will break up into droplets, no matter how smoothly the stream is emitted from the faucet. This is due to a phenomenon called the Plateau–Rayleigh instability, which is entirely a consequence of the effects of surface tension. The explanation of this instability begins with the existence of tiny perturbations in the stream.

Between 1987 and 1992, a variety of pressure sensors, tilt sensors, temperature probes, and seismometers were dropped on the volcano in what came to be known as the Volcanic Systems Moninters (VSN). Further bathymetries by the in 1991 and RV Sonne in 1996 detailed the seamount further, making it one of the best known features in the North Pacific. Also in 1996, the New Millennium Observatory (NeMO) was established on Axial Seamount, to study volcanic perturbations and the effect they have on hydrothermal communities.

It can give a more realistic analysis of the practical performance of the algorithm, such as its running time, than using worst-case or average-case scenarios. Smoothed analysis is a hybrid of worst-case and average-case analyses that inherits advantages of both. It measures the expected performance of algorithms under slight random perturbations of worst-case inputs. If the smoothed complexity of an algorithm is low, then it is unlikely that the algorithm will take a long time to solve practical instances whose data are subject to slight noises and imprecisions.

PSQM as originally conceived was not developed to account for network Quality of Service perturbations common in Voice over IP applications, items such as packet loss, delay variance (jitter) or non-sequential packets. These conditions usually give inappropriate results under heavy network load simulations, failing to account for a very real perceived loss of voice quality. Attempts to duplicate network fault conditions by introducing significant packet loss result in PSQM values that correspond to falsely inflated MOS values. In order to overcome this limitation, PSQM+ was developed by modifying the original algorithm.

That ELVES was discovered in the Shuttle Video by the Mesoscale Lightning Experiment (MLE) team at Marshall Space Flight Center, AL led by the Principal Investigator, Otha H."Skeet" Vaughan, Jr. ELVES is a whimsical acronym for Emissions of Light and Very Low Frequency Perturbations due to Electromagnetic Pulse Sources.The Free Dictionary – ELVES This refers to the process by which the light is generated; the excitation of nitrogen molecules due to electron collisions (the electrons possibly having been energized by the electromagnetic pulse caused by a discharge from an underlying thunderstorm).

Kepler-447b is a confirmed exoplanet. The planet's mass and radius indicate that it is a gas giant with a bulk composition similar to that of Jupiter. Unlike Jupiter, but similar to many planets detected around other stars, Kepler-447b is located very close to its star, and belongs to the class of planets known as hot Jupiters. It has an extremely grazing transit, a property that could be used to detect further properties such as perturbations of the orbit due to other nearby objects or stellar pulsations.

This variability causes the star to range in visual magnitude from 12.23 to 12.34. In 1950, this became the first star to have a small variation in magnitude attributed to spots on its photosphere. Examining the proper motion of Ross 248 has found no evidence of a brown dwarf or stellar companion orbiting between 100–1400 AU, and other unsuccessful searches have been attempted using both the Hubble Space Telescope Wide Field Planetary Camera and by near-infrared speckle interferometry. Long-term observations by the Sproul Observatory show no astrometric perturbations by any unseen companion.

Tocchini-Valentini has also contributed to current understanding of enzyme-substrate rules, stemming from his publication on RNase P and endonuclease from Xenopus laevis cell types. He characterized the tRNA endonucleases of Archaea, finding three forms of tRNA endonuclease. His current research focus is using an archaeal endonuclease (MJ-EndA) to control splicing in both live mice and mice lines. This emergent technology, which can perform both cis- and trans-splicing, allows perturbations to be introduced at the RNA level, thus allowing more specific targeting in mRNA as well as other RNAs.

The concept of self-propelled particles (SPP) was introduced in 1995 by Tamás Vicsek et al. as a special case of the boids model introduced in 1986 by Reynolds. An SPP swarm is modelled by a collection of particles that move with a constant speed and respond to random perturbations by adopting at each time increment the average direction of motion of the other particles in their local neighbourhood. Simulations demonstrate that a suitable "nearest neighbour rule" eventually results in all the particles swarming together, or moving in the same direction.

Jacques Laskar and his colleague Mickaël Gastineau in 2008 took a more thorough approach by directly simulating 2500 possible futures. Each of the 2500 cases has slightly different initial conditions: Mercury's position varies by about 1 metre between one simulation and the next. In 20 cases, Mercury goes into a dangerous orbit and often ends up colliding with Venus or plunging into the Sun. Moving in such a warped orbit, Mercury's gravity is more likely to shake other planets out of their settled paths: in one simulated case its perturbations sent Mars heading towards Earth.

The tables below list selected orbital elements and physical properties of radar-detected minor planets listed by region of the Solar System: asteroid belt, near-Earth objects, or trans-Neptunian objects. The semi-major axis (a), orbital eccentricity (e), inclination (i) to the ecliptic, and orbital period (P) is shown. Where possible, the number of decimals in maintained to the same limited level of significance in each column. This is because further detail is not needed for comparison purposes, and because the values can slightly change over time due to new measurements or gravitational perturbations.

Like other tasks in computer vision such as recognition and detection, recent neural network based retrieval algorithms are susceptible to adversarial attacks, both as candidate and the query attacks. It is shown that retrieved ranking could be dramatically altered with only small perturbations imperceptible to human beings. In addition, model-agnostic transferable adversarial examples are also possible, which enables black-box adversarial attacks on deep ranking systems without requiring access to their underlying implementations. Conversely, the resistance to such attacks can be improved via adversarial defenses such as the Madry defense.

Frank Charles Hoppensteadt (born 29 April 1938)biographical information according to American Men and Women of Science, Thomson Gale 2004}} is an American mathematician, specializing in mathematical biology and dynamical systems. Frank Hoppensteadt studied physics and mathematics at Butler University with bachelor's degree in 1960. At the University of Wisconsin–Madison, he received in 1962 his master's degree and in 1965 his PhD with thesis Singular perturbations on the infinite interval under the supervision of Fred Guenther Brauer and Wolfgang Wasow. From 1965 Hoppensteadt was an assistant professor at Michigan State University in East Lansing.

Polana is in a 1:2 orbital resonance with Mars, meaning that Polana orbits the Sun once for every two orbits that Mars completes. This resonance helps protect the asteroid from orbital erosion: the orbital eccentricities of the resonant asteroids are clearly greater than the non- resonant asteroids. There is a peak in the number of asteroids located at 2.419 AU from the Sun. In spite of strong perturbations caused by the passing of both Jupiter and Mars, the 1:2 Mars resonance brings about stability for billions of years.

Many missions were failures at launch. In addition, several uncrewed landing missions achieved the Lunar surface but were unsuccessful, including: Luna 15, Luna 18, and Luna 23 all crashed on landing; and the U.S. Surveyor 4 lost all radio contact only moments before its landing. More recently, other nations have crashed spacecraft on the surface of the Moon at speeds of around , often at precise, planned locations. These have generally been end-of-life lunar orbiters that, because of system degradations, could no longer overcome perturbations from lunar mass concentrations ("masscons") to maintain their orbit.

In contrast to the coarse counter in the previous section, fine measurement methods with much better accuracy but far smaller measuring range are presented here. Analogue methods like time interval stretching or double conversion as well as digital methods like tapped delay lines and the Vernier method are under examination. Though the analogue methods still obtain better accuracies, digital time interval measurement is often preferred due to its flexibility in integrated circuit technology and its robustness against external perturbations like temperature changes. The counter implementation's accuracy is limited by the clock frequency.

Short- period comets originate in the Kuiper belt or its associated scattered disc, which lie beyond the orbit of Neptune. Long-period comets are thought to originate in the Oort cloud, a spherical cloud of icy bodies extending from outside the Kuiper belt to halfway to the nearest star. Long-period comets are set in motion towards the Sun from the Oort cloud by gravitational perturbations caused by passing stars and the galactic tide. Hyperbolic comets may pass once through the inner Solar System before being flung to interstellar space.

A Capsule Neural Network (CapsNet) is a machine learning system that is a type of artificial neural network (ANN) that can be used to better model hierarchical relationships. The approach is an attempt to more closely mimic biological neural organization. The idea is to add structures called “capsules” to a convolutional neural network (CNN), and to reuse output from several of those capsules to form more stable (with respect to various perturbations) representations for higher capsules. The output is a vector consisting of the probability of an observation, and a pose for that observation.

The immune system is a network of genetic and signaling pathways connected by a network of interacting cells. The Immunological Genome Project seeks to generate a complete compendium of protein-coding gene expression for all cell populations in the mouse immune system. It analyzes both steady-state conditions within different cell populations, and in response to genetic and/or environmental perturbations created by natural genetic polymorphism, gene knock-out, gene knock-down by RNAi, or drug treatment. Computational tools to reverse-engineer or predict immune cell regulatory networks use these expression profiles.

This alone is not enough to protect Pluto; perturbations from the planets (especially Neptune) could alter Pluto's orbit (such as its orbital precession) over millions of years so that a collision could be possible. However, Pluto is also protected by its 2:3 orbital resonance with Neptune: for every two orbits that Pluto makes around the Sun, Neptune makes three. Each cycle lasts about 495 years. This pattern is such that, in each 495-year cycle, the first time Pluto is near perihelion, Neptune is over 50° behind Pluto.

For example, Jupiter has a synodic period of 398.8 days from Earth; thus, Jupiter's opposition occurs once roughly every 13 months. Periods in astronomy are conveniently expressed in various units of time, often in hours, days, or years. They can be also defined under different specific astronomical definitions that are mostly caused by small complex external gravitational influences by other celestial objects. Such variations also include the true placement of the centre of gravity between two astronomical bodies (barycenter), perturbations by other planets or bodies, orbital resonance, general relativity, etc.

The nature of this modulation is complex, particularly on climate time-scales (decades or longer). On shorter time-scales, variability in the maximum potential intensity is commonly linked to sea surface temperature perturbations from the tropical mean, as regions with relatively warm water have thermodynamic states much more capable of sustaining a tropical cyclone than regions with relatively cold water. However, this relationship is indirect via the large- scale dynamics of the tropics; the direct influence of the absolute sea surface temperature on v_p is weak in comparison.

Spiru C. Haret (; 15 February 1851 – 17 December 1912) was a Romanian mathematician, astronomer and politician. He made a fundamental contribution to the n-body problem in celestial mechanics by proving that using a third degree approximation for the disturbing forces implies instability of the major axes of the orbits, and by introducing the concept of secular perturbations in relation to this. As a politician, during his three terms as Minister of Education, Haret ran deep reforms, building the modern Romanian education system. He was made a full member of the Romanian Academy in 1892.

For higher (lower) values of Reynolds number, the rightmost eigenvalue shifts into the positive (negative) half of the complex plane. Then, a fuller picture of the stability properties is given by a plot exhibiting the functional dependence of this eigenvalue; this is shown in the second figure. On the other hand, the spectrum of eigenvalues for Couette flow indicates stability, at all Reynolds numbers. However, in experiments, Couette flow is found to be unstable to small, but finite, perturbations for which the linear theory, and the Orr–Sommerfeld equation do not apply.

Mayor's team employed the radial velocity technique, in which the orbit size and mass of a planet are determined based on the small perturbations it induces in its parent star's orbit via gravity. At a minimum mass of 1.7 Earth masses, it is one of the least massive extrasolar planets discovered around a normal star, and relatively close in mass to Earth. It is also the exoplanet with the smallest accurate true mass known. At an orbital distance of just from its parent star, however, it orbits further in than the habitable zone.

Kerala state received unprecedented rains during the month of July 1924. Kerala received 3,368 mm of rain during the monsoon season (June to September), 64 per cent higher than normal and is the highest recorded rainfall. The flood was probably caused by offshore vortices along the west coast and perturbations higher up in the troposphere and is not attributed to any depression or cyclonic disturbance in the Arabian sea or the bay of Bengal. The rivers in the state were in spate and a sudden opening of the Mullaperiyar sluices caused even greater misery.

When Uranus and Neptune are near but not in a mean-motion resonance the locations where Uranus passes Neptune can circulate with a period that is in resonance with the libration periods of Neptune trojans. This results in repeated perturbations that increase the libration of existing trojans causing their orbits to become unstable. This process is reversible allowing new trojans to be captured when the planetary migration continues. For high-inclination trojans to be captured the migration must have been slow, or their inclinations must have been acquired previously.

Under experimentally achievable conditions for gravitational systems this effect is too small to be observed directly. However, in September 2010 an experimental set-up created a laboratory "white hole event horizon" that the experimenters claimed was shown to radiate an optical analog to Hawking radiation, although its status as a genuine confirmation remains in doubt. Some scientists predict that Hawking radiation could be studied by analogy using sonic black holes, in which sound perturbations are analogous to light in a gravitational black hole and the flow of an approximately perfect fluid is analogous to gravity.

Each Fourier mode is normally distributed (usually called Gaussian) with mean zero. Different Fourier components are uncorrelated. The variance of a mode depends only on its wavelength in such a way that within any given volume each wavelength contributes an equal amount of power to the spectrum of perturbations. Since the Fourier transform is in three dimensions, this means that the variance of a mode goes as k−3 to compensate for the fact that within any volume, the number of modes with a given wavenumber k goes as k3.

Various inflation theories have been proposed that make radically different predictions, but they generally have much more fine tuning than should be necessary. As a physical model, however, inflation is most valuable in that it robustly predicts the initial conditions of the Universe based on only two adjustable parameters: the spectral index (that can only change in a small range) and the amplitude of the perturbations. Except in contrived models, this is true regardless of how inflation is realized in particle physics. Occasionally, effects are observed that appear to contradict the simplest models of inflation.

Similar to recognition applications in computer vision, recent neural network based ranking algorithms are also found to be susceptible to covert adversarial attacks, both on the candidates and the queries. With small perturbations imperceptible to human beings, ranking order could be arbitrarily altered. In addition, model-agnostic transferable adversarial examples are found to be possible, which enables black-box adversarial attacks on deep ranking systems without requiring access to their underlying implementations. Conversely, the robustness of such ranking systems can be improved via adversarial defenses such as the Madry defense.

The ekpyrotic and cyclic models are also considered adjuncts to inflation. These models solve the horizon problem through an expanding epoch well before the Big Bang, and then generate the required spectrum of primordial density perturbations during a contracting phase leading to a Big Crunch. The Universe passes through the Big Crunch and emerges in a hot Big Bang phase. In this sense they are reminiscent of Richard Chace Tolman's oscillatory universe; in Tolman's model, however, the total age of the Universe is necessarily finite, while in these models this is not necessarily so.

Lunar Gateway, one of the proposed space stations for crewed cislunar travel in the 2020s Earth's gravity keeps the Moon in orbit at an average distance of . The region outside Earth's atmosphere and extending out to just beyond the Moon's orbit, including the Lagrange points, is sometimes referred to as cislunar space. The region of space where Earth's gravity remains dominant against gravitational perturbations from the Sun is called the Hill sphere. This extends well out into translunar space to a distance of roughly 1% of the mean distance from Earth to the Sun, or .

The Metonic cycle is equal to one Saros cycle plus one lunar year, and so the two series progress in parallel. The Inex cycle (29 years minus 20 days) can last tens of thousands of years, so long that long perturbations in the moon's path must be taken into account for prediction. Also the eclipse qualities are less inconsistent because the moon is at different significantly positions in its elliptical orbit in sequential events. Similarly for the shorter Tritos cycle (10 years and 31 days), repeats less consistently for same reason.

In 1919, the renowned physicist, Albert A. Michelson, noted that the most favorable arrangement to obtain high sensitivity and immunity from temperature perturbations is to use the equipotential surface defined by water in a buried half-filled water pipe. This was a simple arrangement of two water pots, connected by a long water- filled tube. Any change in tilt would be registered by a difference in fill- mark of one pot compared to the other. Although extensively used throughout the world for earth-science research, they have proven to be quite difficult to operate.

In quantum physics and quantum chemistry, each set of degenerate eigenstates of the Hamiltonian operator comprises a vector space for a representation of the symmetry group of the Hamiltonian, a "multiplet", best studied through reduction to its irreducible parts. Identifying the irreducible representations therefore allows one to label the states, predict how they will split under perturbations; or transition to other states in . Thus, in quantum mechanics, irreducible representations of the symmetry group of the system partially or completely label the energy levels of the system, allowing the selection rules to be determined.

Quite often, Primes are not evident without a significant amount of replications, over a significant period of time, to observe that something influential and indivisible of its parts has presented itself: "When we consider the class of these great moments, we are usually confronted with dead stars. Even their light has ceased to reach us. We know of their existence only indirectly, by their perturbations, and by the immense detritus of derivative stuff left in their paths." At this point in Chapter 2 Kubler compares great moments in art and inspired ideas to "dead stars".

The NASA Earth Global Reference Atmospheric Model (Earth-GRAM) was developed by the Marshall Space Flight Center to provide a design reference atmosphere that, unlike the standard atmospheres, allows for geographical variability, a wide range of altitudes (surface to orbital altitudes), and different months and times of day. It can also simulate spatial and temporal perturbations in atmospheric parameters due to turbulence and other atmospheric perturbation phenomena. It is available in computer code written in Fortran. The GRAM series also includes atmospheric models for the planets Venus, Mars and Neptune and the Saturnian moon, Titan.

Comets are in unstable orbits that evolve over time due to perturbations and outgassing. Given Encke's low orbital inclination near the ecliptic and brief orbital period of 3 years, the orbit of Encke is frequently perturbed by the inner planets. Encke is currently close to a 7:2 mean motion resonance with Jupiter, and it is possible that some of the larger fragments shed by the comet, or released by a larger progenitor of the comet, are trapped in this resonance. Encke's orbit gets as close as to Earth (minimum orbit intersection distance).

Molecular phenotyping describes the technique of quantifying pathway reporter genes, i.e. pre-selected genes that are modulated specifically by metabolic and signaling pathways, in order to infer activity of these pathways. In most cases, molecular phenotyping quantifies changes of pathway reporter gene expression to characterize modulation of pathway activities induced by perturbations such as therapeutic agents or stress in a cellular system in vitro. In such contexts, measurements at early time points are often more informative than later observations because they capture the primary response to the perturbation by the cellular system.

Graphic rapresentation of JPL Horizons On-Line Ephemeris System output values JPL Horizons On-Line Ephemeris System provides easy access to key Solar System data and flexible production of highly accurate ephemerides for Solar System objects. Osculating elements at a given epoch are always an approximation to an object's orbit (i.e. an unperturbed conic orbit or a "two-body" orbit). The real orbit (or the best approximation to such) considers perturbations by all planets, a few of the larger asteroids, a few other usually small physical forces, and requires numerical integration.

Stefansson and his team have used the breadth of the company's datasets and links between diseases and traits to discover new risk variants for mental illness, but also to refine the understanding of the perturbations that define these conditions and the nature of cognition itself. Studies in the early 2000s mapped the involvement of the Neuregulin 1 gene in schizophrenia, leading to substantial research in this novel pathway.H Stefansson et al., "Neuregulin 1 and susceptibility to schizophrenia," American Journal of Human Genetics, Volume 71, Issue 4, pp 877-892, October 2002.

From the patients in group 2 which postural recordings could be made, 7 patients suffered from hemiparetic lesion on the left side and 10 had lesions on the right. Of the patients in group 1, 4 had lesion to the left side and 3 on the right. Upon testing, the subjects stood on a platform with their heels together and their arms crossed over their chests. The subjects were exposed to perturbations via vibratory stimulus on their calf muscles, which caused anteroposterior movement, or galvanic stimulation of the vestibular nerves, causing lateral movement.

The geostationary ring is a volume segment around the geostationary orbit defined by variations in altitude and declination that can occur for uncontrolled objects left in the geostationary orbit. The geostationary orbit is subject to orbit perturbations caused by anomalies in the gravitational field of the Earth, by the gravitational effects of Sun and Moon, and by solar radiation pressure. A precessional motion of the orbit plane is caused by the oblatedness of the Earth (J_2), and the gravitational effects of Sun and Moon. This motion has a period of about 53 years.

Thermal perturbations are the most common type of external stimulus used to induce SCO. One example is [FeII(tmphen)2]3[CoIII(CN)6]2 trigonal bipyramid (TBP), with the FeII centers in the equatorial positions. The HS FeII remains under 20% i the range of 4.2 K to 50 K, but at room temperature about two-thirds of the FeII ions in the sample are HS, as shown by the absorption band at 2.1 mm/s, while the other third of the ions remain in the LS state.

This unique structure which detects rotations/perturbations during flight has never been described in nature elsewhere. Directions of rotation Halteres are able to sense small deviations in body position using the gyroscopic properties of moving mass. What this means is that halteres beat up and down in time with the flapping of the wings along a linear pathway, but when the fly's body begins to rotate, the path of the beating halteres also changes. Now, instead of the halteres following a linear path, they begin to follow a curved path.

The distance to the Moon can be measured to an accuracy of over a 1-hour sampling period, which results in an overall uncertainty of for the average distance. However, due to its elliptical orbit with varying eccentricity, the instantaneous distance varies with monthly periodicity. Furthermore, the distance is perturbed by the gravitational effects of various astronomical bodies – most significantly the Sun and less so Jupiter. Other forces responsible for minute perturbations are: gravitational attraction to other planets in the solar system and to asteroids; tidal forces; and relativistic effects.

The very early universe is still a poorly understood epoch, from the viewpoint of fundamental physics. The prevailing theory, cosmic inflation, does a good job explaining the observed flatness, homogeneity and isotropy of the universe, as well as the absence of exotic relic particles (such as magnetic monopoles). Another prediction borne out by observation is that tiny perturbations in the primordial universe seed the later formation of structure. These fluctuations, while they form the foundation for all structure, appear most clearly as tiny temperature fluctuations at one part in 100,000.

Another important property of the primordial perturbations, that they are adiabatic (or isentropic between the various kinds of matter that compose the universe), is predicted by cosmic inflation and has been confirmed by observations. Other theories of the very early universe have been proposed that are claimed to make similar predictions, such as the brane gas cosmology, cyclic model, pre-big bang model and holographic universe, but they remain nascent and are not widely accepted. Some theories, such as cosmic strings, have largely been refuted by increasingly precise data.

Skirting the inner edge of the belt (ranging between 1.78 and 2.0 AU, with a mean semi- major axis of 1.9 AU) is the Hungaria family of minor planets. They are named after the main member, 434 Hungaria; the group contains at least 52 named asteroids. The Hungaria group is separated from the main body by the 4:1 Kirkwood gap and their orbits have a high inclination. Some members belong to the Mars-crossing category of asteroids, and gravitational perturbations by Mars are likely a factor in reducing the total population of this group.

For functional genomics, metabolomics can be an excellent tool for determining the phenotype caused by a genetic manipulation, such as gene deletion or insertion. Sometimes this can be a sufficient goal in itself—for instance, to detect any phenotypic changes in a genetically modified plant intended for human or animal consumption. More exciting is the prospect of predicting the function of unknown genes by comparison with the metabolic perturbations caused by deletion/insertion of known genes. Such advances are most likely to come from model organisms such as Saccharomyces cerevisiae and Arabidopsis thaliana.

A simple example of a shear flow is Couette flow, in which a fluid is trapped between two large parallel plates, and one plate is moved with some relative velocity to the other. Here, the strain rate is simply the relative velocity divided by the distance between the plates. Shear flows in fluids tend to be unstable at high Reynolds numbers, when fluid viscosity is not strong enough to dampen out perturbations to the flow. For example, when two layers of fluid shear against each other with relative velocity, the Kelvin–Helmholtz instability may occur.

Also, due to the impulsive form of the disturbance, higher-order terms are generated which, however, possess short decay times and thus quickly disappear. The sum of these modes determines the "travel time" of the disturbance to the lower latitudes, and thus the response time of the thermosphere with respect to the magnetospheric disturbance. Important for the development of an ionospheric storm is the increase of the ratio N2/O during a thermospheric storm at middle and higher latitude.Prölss, G.W., Density perturbations in the upper atmosphere caused by dissipation of solar wind energy, Surv. Geophys.

Ice forms on rivers and lakes in response to seasonal cooling. The sizes of the ice bodies involved are too small to exert anything other than localized climatic effects. However, the freeze- up/break-up processes respond to large-scale and local weather factors, such that considerable interannual variability exists in the dates of appearance and disappearance of the ice. Long series of lake-ice observations can serve as a proxy climate record, and the monitoring of freeze-up and break-up trends may provide a convenient integrated and seasonally-specific index of climatic perturbations.

Moreover, during fault conditions electromagnetic perturbations may rise significantly and disturb those communications channels based on copper wires. The reliability of the communications link interconnecting the protection relays is critical and therefore must be resistant to effects encountered in high voltage areas, such as high frequency induction and ground potential rise. Consequently, the power industry moved to optical fibers to interconnect the different items installed in substations. Fiber optics need not be grounded and are immune to the interferences caused by electrical noise, eliminating many of the errors commonly seen with electrical connections.

Typical lunar transfer trajectories approximate Hohmann transfers, although low-energy transfers have also been used in some cases, as with the Hiten probe. For short duration missions without significant perturbations from sources outside the Earth-Moon system, a fast Hohmann transfer is typically more practical. A spacecraft performs TLI to begin a lunar transfer from a low circular parking orbit around Earth. The large TLI burn, usually performed by a chemical rocket engine, increases the spacecraft's velocity, changing its orbit from a circular low Earth orbit to a highly eccentric orbit.

The relative masses of the Neptunian moons Triton's orbit upon capture would have been highly eccentric, and would have caused chaotic perturbations in the orbits of the original inner Neptunian satellites, causing them to collide and reduce to a disc of rubble. This means it is likely that Neptune's present inner satellites are not the original bodies that formed with Neptune. Only after Triton's orbit became circularised could some of the rubble re-accrete into the present-day regular moons. The mechanism of Triton's capture has been the subject of several theories over the years.

In general, these disturbances take an arbitrary form and are thus difficult to consider rigorously. It is therefore helpful to take a Fourier transform of the disturbances to decompose the arbitrary disturbances into perturbations of various single wavelengths on the surface of the thread. In doing so, this allows one to determine which wavelengths of the disturbance will grow and which will decay in time. The growth and decay of wavelengths can be determined by examining the change in pressure a perturbation wavelength imposes on the interior of the fluid thread.

His writings relate to almost every branch of celestial mechanics, and are always distinguished by rigour and simplicity in the solution of the most difficult problems. He treated in a masterly manner (Bulletin astronomique, 1889) the theory of the capture of comets by the larger planets, and in this connection published his valuable Criterion for establishing the identity of a periodic comet, whatever may have been the perturbations brought about in its orbit, between successive appearances, by the action of a planet. His principal work, Traité de mécanique céleste,Vol. I, Vol.

Von Neumann's insight was to think of life as a Turing Machine, which, is similarly defined by a state-determined machine "head" separated from a memory tape. In practice, when we consider the particular automata implementation Von Neumann pursued, we conclude that it does not yield much evolutionary dynamics because the machines are too fragile - the vast majority of perturbations cause them effectively to disintegrate. Thus, it is the conceptual model outlined in his Illinois lectures that is of greater interest today because it shows how a machine can in principle evolve.

Orbit modeling is the process of creating mathematical models to simulate motion of a massive body as it moves in orbit around another massive body due to gravity. Other forces such as gravitational attraction from tertiary bodies, air resistance, solar pressure, or thrust from a propulsion system are typically modeled as secondary effects. Directly modeling an orbit can push the limits of machine precision due to the need to model small perturbations to very large orbits. Because of this, perturbation methods are often used to model the orbit in order to achieve better accuracy.

It involves the identification and quantification of the thousands of cellular lipid molecular species and their interactions with other lipids, proteins, and other moieties in vivo. Investigators in lipidomics examine the structures, functions, interactions, and dynamics of cellular lipids and the dynamic changes that occur during pathophysiologic perturbations. Lipidomic studies play an essential role in defining the biochemical mechanisms of lipid-related disease processes through identifying alterations in cellular lipid metabolism, trafficking and homeostasis. The two major platforms currently used for lipidomic analyses are HPLC-MS and shotgun lipidomics.

The Turbulent Gas Jet Diffusion Flames (TGDF) payload is a secondary payload that used the standard Get Away Special carrier. Its purpose is to gain an understanding of the fundamental characteristics of transitional and turbulent gas jet diffusion flames under microgravity conditions and to acquire data that will aid in predicting the behavior of transitional and turbulent gas jet diffusion flames under normal and microgravity environments. TGDF will impose large- scale controlled disturbances on well-defined laminar microgravity diffusion flames. The will be on axisymmetric perturbations to laminar flames.

The trajectory of successional change can be influenced by site conditions, by the character of the events initiating succession (perturbations), by the interactions of the species present, and by more stochastic factors such as availability of colonists or seeds or weather conditions at the time of disturbance. Some of these factors contribute to predictability of succession dynamics; others add more probabilistic elements. Two important perturbation factors today are human actions and climatic change. In general, communities in early succession will be dominated by fast-growing, well-dispersed species (opportunist, fugitive, or r-selected life-histories).

The so-called coclass conjectures described the set of all finite p-groups of fixed coclass as perturbations of finitely many pro-p groups. The coclass conjectures were proven in the 1980s using techniques related to Lie algebras and powerful p-groups. The final proofs of the coclass theorems are due to A. Shalev and independently to C. R. Leedham-Green, both in 1994. They admit a classification of finite p-groups in directed coclass graphs consisting of only finitely many coclass trees whose (infinitely many) members are characterized by finitely many parametrized presentations.

Jacques Babinet, an early proponent of a trans-Neptunian planet In the 1840s, the French mathematician Urbain Le Verrier used Newtonian mechanics to analyse perturbations in the orbit of Uranus, and hypothesised that they were caused by the gravitational pull of a yet-undiscovered planet. Le Verrier predicted the position of this new planet and sent his calculations to German astronomer Johann Gottfried Galle. On 23 September 1846, the night following his receipt of the letter, Galle and his student Heinrich d'Arrest discovered Neptune, exactly where Le Verrier had predicted.Croswell (1997), p.

This sample tests for glycosylated hemoglobin (HbA1c) levels; HbA1c gives healthcare professionals an idea of blood glucose levels and is the most reliable form of testing for diabetes in asymptomatic patients. Fasting and “acute perturbations” are not needed for HbA1c test and it reveals average glycemic control over 3 month period. HbA1c less than 5.6% is considered normal. Glucose status can also be tested through fasting blood sugar (FBS) and requires a blood sample after a patient has fasted for at least eight hours, so it might not be as convenient.

Wagner's work revolves around the robustness of biological systems, and about their ability to innovate, that is, to create novel organisms and traits that help them survive and reproduce. Robustness is the ability of a biological system to withstand perturbations, such as DNA mutations and environmental change. Early in his career Wagner developed a widely used mathematical model for gene regulatory circuits,Wagner A (1994) Evolution of gene networks by gene duplications: a mathematical model and its implications on genome organization. Proc. Natl. Acad. Sci. U.S.A. 91 4387-4391.

The average diameter of the reference spheroid is . Local topography deviates from this idealized spheroid, although on a global scale these deviations are small compared to Earth's radius: the maximum deviation of only 0.17% is at the Mariana Trench ( below local sea level), whereas Mount Everest ( above local sea level) represents a deviation of 0.14%. In geodesy, the exact shape that Earth's oceans would adopt in the absence of land and perturbations such as tides and winds is called the geoid. More precisely, the geoid is the surface of gravitational equipotential at mean sea level.

Generally, the techniques and methods used are guided by two principles: distanciation and over-identification. Distanciation is based on subtle modifications in the regular representation, which lights new aspects of the representation and produces by displacement, new meanings unforecast. It consists on taking images, ideas and forms to change the communication process or its usual presentation to create confusion and reconsideration about each own cultural grammar. The new elements in the communication process create perturbations, which are effective to offer a critic vision to general public in front of the traditional point of view.

Finally, for small perturbations in subsonic and supersonic flows (not transonic or hypersonic) these equations can be linearized to yield the linearized potential equations. Historically, methods were first developed to solve the linearized potential equations. Two-dimensional (2D) methods, using conformal transformations of the flow about a cylinder to the flow about an airfoil were developed in the 1930s. One of the earliest type of calculations resembling modern CFD are those by Lewis Fry Richardson, in the sense that these calculations used finite differences and divided the physical space in cells.

This is a matter of convention, but the convention is defined in terms of the equator and ecliptic as they were in 1875. To find out in which constellation a particular comet stands today, the current position of that comet must be expressed in the coordinate system of 1875 (equinox/equator of 1875). Thus that coordinate system can still be used today, even though most comet predictions made originally for 1875 (epoch = 1875) would no longer, because of the lack of information about their time- dependence and perturbations, be useful today.

Renooz became the subject of fresh ridicule when, after S. A. Andrée's Arctic Balloon Expedition of 1897, Renooz published a letter about the expedition in Le Matin. She attributed the expedition's failure to polar winds, which—according to the oxygen theories she had laid out in La Nouvelle Science—made polar discovery impossible. Published responses to Renooz's letter ranged from simple satire to contradiction based on evidence (including a refutation from the geographer Élisée Reclus), but all were dismissive. Other physics ideas Renooz espoused included the theory that perturbations on Mars were caused by incandescence.

Although both dark matter and ordinary matter are matter, they do not behave in the same way. In particular, in the early universe, ordinary matter was ionized and interacted strongly with radiation via Thomson scattering. Dark matter does not interact directly with radiation, but it does affect the CMB by its gravitational potential (mainly on large scales), and by its effects on the density and velocity of ordinary matter. Ordinary and dark matter perturbations, therefore, evolve differently with time and leave different imprints on the cosmic microwave background (CMB).

The International Special Committee for Radio Interference or CISPR (French acronym for "Comité International Spécial des Perturbations Radioélectriques"), which is a committee of the International Electrotechnical Commission (IEC) sets international standards for radiated and conducted electromagnetic interference. These are civilian standards for domestic, commercial, industrial and automotive sectors. These standards form the basis of other national or regional standards, most notably the European Norms (EN) written by CENELEC (European committee for electrotechnical standardisation). US organizations include the Institute of Electrical and Electronics Engineers (IEEE), the American National Standards Institute (ANSI), and the US Military (MILSTD).

His group has studied implications of these methods for the recovery of lost function in biological Motter A. E., Gulbahce N., Almaas E., and Barabasi A.-L., Predicting Synthetic Rescues in Metabolic Networks, Molecular Systems Biology 4, 168 (2008).Work with Power Grids Leads to Cell Biology Discovery. and ecological Sahasrabudhe S. and Motter A. E, Rescuing Ecosystems from Extinction Cascades through Compensatory Perturbations, Nature Communications 2, 170 (2011).Mathematical model could help predict and prevent future extinctions, National Science Foundation, January 25, 2011, by Lisa Van Pay.

The equilateral pick can be easier for beginners to hold and use since each corner may be used as a playing edge. The shark's fin pick can be used in two ways: normally, employing the blunt end; or the small perturbations can be raked across the strings producing a much fuller chord, or used to apply a "pick scrape" down the strings producing a very harsh, scratching noise. The sharp edged pick is used to create an easier motion of picking across the strings. Some guitar pick shapes are patented.

The CYR61 promoter is a TATA box containing promoter, with binding sites for many transcription factors including AP1, ATF, E2F, HNF3b, NF1, NFκB, SP1, and SRF, and 2 poly(CA) stretches that may form Z-DNA structure. Transcriptional activation of CYR61 is exquisitely sensitive to a wide range of environmental perturbations, including stimulation by platelet-derived growth factor and basic fibroblast growth factor, transforming growth factor β1 (TGF-β1), growth hormone, the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), cAMP, vitamin D3, estrogen and tamoxifen, angiotensin II, hypoxia, UV light, and mechanical stretch.

The amount of rock that was excavated there is many times more than enough to account for all known V-type asteroids. # Some of the more far-flung asteroid debris ended up in the 3:1 Kirkwood gap. This is an unstable region due to strong perturbations by Jupiter, and asteroids which end up here get ejected onto far different orbits on a timescale of about 100 million years. Some of these bodies are perturbed into near-Earth orbits forming the small V-type near-Earth asteroids such as e.g.

Within a planetary system, planets, dwarf planets, asteroids and other minor planets, comets, and space debris orbit the system's barycenter in elliptical orbits. A comet in a parabolic or hyperbolic orbit about a barycenter is not gravitationally bound to the star and therefore is not considered part of the star's planetary system. Bodies which are gravitationally bound to one of the planets in a planetary system, either natural or artificial satellites, follow orbits about a barycenter near or within that planet. Owing to mutual gravitational perturbations, the eccentricities of the planetary orbits vary over time.

That is, by proper association of the astronomical phases, observations made at one time can enable predictions decades away with different astronomical phases. Doodson published a major work on tidal analysis in 1921. This was the first development of the tide generating potential (TGP) to be carried out in harmonic form: Doodson distinguished 388 tidal frequencies.S Casotto, F Biscani, "A fully analytical approach to the harmonic development of the tide- generating potential accounting for precession, nutation, and perturbations due to figure and planetary terms", AAS Division on Dynamical Astronomy, April 2004, vol.

Above the boundary layer, the fluid behaves approximately like a perfect fluid. But within the boundary layer, the velocity of the flow changes rapidly from the high velocity above the boundary layer to a velocity of 0 at the solid surface. Many technical problems can be modeled this way, including the flow of a liquid through a pipe and the flow of air over an airplane wing. Boundary layer problems are instances of a more general class of problems that today is part of the field of singular perturbations.

Incidentally, this SNP is also associated with fear discrimination. The study suggests that perturbations in the PACAP-PAC1 pathway are involved in abnormal stress responses underlying PTSD. PTSD is a psychiatric disorder that requires an environmental event that individuals may have varied responses to so gene-environment studies tend to be the most indicative of their effect on the probability of PTSD then studies of the main effect of the gene. Recent studies have demonstrated the interaction between PFBP5 and childhood environment to predict the severity of PTSD.

The innovation butterfly arises because many innovation systems are made up of a large number of elements that interact with each other via several non-linear feedback loops containing embedded delays, thus constituting a complex system.Sterman, J.D. (1994). "Learning in and about Complex Systems", System Dynamics Review, 10(2-3): 291-330. Perturbations can come from decisions made within the firm or from those made by its competitors, or they can result from external forces such as government legislation or environmental regulations, or unexpected spikes in the price of oil.

Inflationary models generically predict that a gravitational-wave background (GWB) would have been produced along with the density perturbations that seed large-scale structure. Such an inflationary GWB would leave an imprint on both the temperature and polarization of the CMB. In particular it would leave a distinctive and unique pattern of polarization, called a B-mode pattern, in the CMB polarization. A measurement of B-mode polarization in the CMB would be important confirmation of inflation and would provide a rare glimpse into physics at ultra-high energies.

It is a generalisation of earlier neural network architectures such as recurrent neural networks, liquid-state machines and echo-state networks. Reservoir computing also extends to physical systems that are not networks in the classical sense, but rather continuous systems in space and/or time: e.g. a literal "bucket of water" can serve as a reservoir that performs computations on inputs given as perturbations of the surface. The resultant complexity of such recurrent neural networks was found to be useful in solving a variety of problems including language processing and dynamic system modeling.

In theoretical physics, a near-extremal black hole is a black hole which is not far from the minimal possible mass that can be compatible with the given charges and angular momentum. The calculations of the properties of near- extremal black holes are usually performed using perturbation theory around the extremal black hole; the expansion parameter is called non-extremality. In supersymmetric theories, near-extremal black holes are often small perturbations of supersymmetric black holes. Such black holes have a very small Hawking temperature and consequently emit a small amount of Hawking radiation.

Kepler's search volume, in the context of the Milky Way The motion of Kepler relative to Earth, slowly drifting away from Earth in a similar orbit, looking like a spiral over time Kepler orbits the Sun, which avoids Earth occultations, stray light, and gravitational perturbations and torques inherent in an Earth orbit. NASA has characterized Kepler's orbit as "Earth-trailing". With an orbital period of 372.5 days, Kepler is slowly falling farther behind Earth (about 16 million miles per annum). , the distance to Kepler from Earth was about .

Among the extreme trans-Neptunian objects are three high-perihelion objects classified as sednoids: 90377 Sedna, , and 541132 Leleākūhonua. They are distant detached objects with perihelia greater than 70 AU. Their high perihelia keep them at a sufficient distance to avoid significant gravitational perturbations from Neptune. Previous explanations for the high perihelion of Sedna include a close encounter with an unknown planet on a distant orbit and a distant encounter with a random star or a member of the Sun's birth cluster that passed near the Solar System.

After decoupling from Mercury's orbit, was shown to oscillate between an Atira-type orbit (Q < 0.983 AU) and an Earth-crossing Aten-type orbit (Q > 0.983 AU), in which the asteroid's aphelion oscillates around Earth's perihelion distance of 0.983 AU. About 740 thousand years afterward, will likely return to its Mercury-crossing orbit, though gravitational perturbations by Mercury and Venus will scatter it onto an Earth-crossing orbit once more before colliding with either planet. At about 4.1 million years from the present, will most likely collide with Venus.

C/1999 F1 made its closest approach to Neptune in August 2017. Using JPL Horizons, the barycentric orbital elements for epoch 2035-Jan-01 generate a semi-major axis of 33,300 AU, an apoapsis distance of 66,600 AU, and a period of approximately 6 million years. Comet West has a similar period. The generic JPL Small-Body Database browser uses a near-perihelion epoch of 2001-May-19 which is before the comet left the planetary region and makes the highly eccentric aphelion point inaccurate since it does not account for any planetary perturbations.

The covariance matrix is important in estimating the initial conditions required for running weather forecast models, a procedure known as data assimilation. The 'forecast error covariance matrix' is typically constructed between perturbations around a mean state (either a climatological or ensemble mean). The 'observation error covariance matrix' is constructed to represent the magnitude of combined observational errors (on the diagonal) and the correlated errors between measurements (off the diagonal). This is an example of its widespread application to Kalman filtering and more general state estimation for time-varying systems.

Cells are typically transduced with a Multiplicity of Infection (MOI) of 0.4 to 0.6 lentiviral particles per cell to maximize the likelihood of obtaining the most amount of cells which contain a single guide RNA. If the effects of simultaneous perturbations are of interest, a higher MOI may be applied to increase the amount of transduced cells with more than one guide RNA. Selection for successfully transduced cells is then performed using a fluorescence assay or an antibiotic assay, depending on the reporter gene used in the expression vector.

Tycho's distinctive contributions to lunar theory include his discovery of the variation of the Moon's longitude. This represents the largest inequality of longitude after the equation of the center and the evection. He also discovered librations in the inclination of the plane of the lunar orbit, relative to the ecliptic (which is not a constant of about 5° as had been believed before him, but fluctuates through a range of over a quarter of a degree), and accompanying oscillations in the longitude of the lunar node. These represent perturbations in the Moon's ecliptic latitude.

Specialists consider his most lasting contribution to physics to be the paper co-written with Theodore A. Welton presenting a proof of the fluctuation- dissipation theorem, an extremely general result describing how a system's response to perturbations relates to its behavior at equilibrium. This crucial result became the basis for the statistical theory of irreversible processes and explains how fluctuations dissipate energy into heat in general and the phenomenon of Nyquist noise in particular. Callen then pioneered the thermodynamic Green's functions for magnetism. With his students, he studied many-body problems involving spin operators.

In hash function, for audio identification, such as finding out whether an MP3 file matches one of a list of known items, one could use a conventional hash function such as MD5, but this would be very sensitive to highly likely perturbations such as time-shifting, CD read errors, different compression algorithms or implementations or changes in volume. Using something like MD5 is useful as a first pass to find exactly-identical files, but another, more advanced algorithm is required to find all items that would nonetheless be interpreted as identical by a human listener.

At this boundary there are slight ripple-like perturbations in which the low points must have a larger current than the high points since at the low point more gravity is being supported against the gravity. The difference in current allows negative and positive charge to build up along the opposite sides of the valley. The charge build-up produces an E field between the hill and the valley. The accompanying E × B drifts are in the same direction as the ripple, amplifying the effect. This is what is physically meant by the “interchange” motion.

Control of chaos is the stabilization, by means of small system perturbations, of one of these unstable periodic orbits. The result is to render an otherwise chaotic motion more stable and predictable, which is often an advantage. The perturbation must be tiny compared to the overall size of the attractor of the system to avoid significant modification of the system's natural dynamics. Several techniques have been devised for chaos control, but most are developments of two basic approaches: the OGY (Ott, Grebogi and Yorke) method, and Pyragas continuous control.

Centaurs are a large population of icy bodies in transition between trans-Neptunian objects (TNOs) and Jupiter-family comets (JFCs), their orbits being unstable due to perturbations by the giant planets. Currently, Uranus controls Hylonomes perihelion and Neptune its aphelion. Hylonome is a carbonaceous C-type body that orbits the Sun in the outer main-belt at a distance of 18.9–31.4 AU once every 126 years and 2 months (46,073 days). Its orbit has an eccentricity of 0.25 and an inclination of 4° with respect to the ecliptic.

The gravitational tidal forces acting on the rings of Saturn provide an easy-to-visualize physical example. The tidal forces flatten the ring into the equatorial plane, even as they stretch it out in the radial direction. Imagining the rings to be sand or gravel particles ("dust") in orbit around Saturn, the tidal forces are such that any perturbations that push particles above or below the equatorial plane results in that particle feeling a restoring force, pushing it back into the plane. Particles effectively oscillate in a harmonic well, damped by collisions.

Usually one of the two conceptualizations is preferred when designing predistortion circuitry; however the end result is generally the same. A predistorter designed to correct gain and phase non-linearities will also improve IMD, while one which targets inter-modulation products will also reduce gain and phase perturbations. When combined with the target amplifier, the linearizer produces an overall system that is more linear and reduces the amplifier's distortion. In essence, "inverse distortion" is introduced into the input of the amplifier, thereby cancelling any non-linearity the amplifier might have.

Thus, as elsewhere in the body, the transduction is dependent on the concentration and distribution of ions. The perilymph that is found in the scala tympani has a low potassium concentration, whereas the endolymph found in the scala media has a high potassium concentration and an electrical potential of about 80 millivolts compared to the perilymph. Mechanotransduction by stereocilia is highly sensitive and able to detect perturbations as small as fluid fluctuations of 0.3 nanometers, and can convert this mechanical stimulation into an electrical nerve impulse in about 10 microseconds.

A fair number of higher polycycles containing the biphenylene nucleus have also been prepared, some having considerable antiaromatic character. In general, additional 6-membered rings add further aromatic character, and additional 4-membered and 8-membered rings add antiaromatic character. However, the exact natures of the additions and fusions greatly affect the perturbations of the biphenylene system, with many fusions resulting in counter-intuitive stabilization by [4n] rings, or destabilization by 6-membered rings. This has led to significant interest in the systems by theoretical chemists and graph theoreticians.

In that paper, Gonzalez, Brownlee, and Ward stated that regions near the galactic halo would lack the heavier elements required to produce habitable terrestrial planets, thus creating an outward limit to the size of the galactic habitable zone. Being too close to the galactic center, however, would expose an otherwise habitable planet to numerous supernovae and other energetic cosmic events, as well as excessive cometary impacts caused by perturbations of the host star's Oort cloud. Therefore, the authors established an inner boundary for the galactic habitable zone, located just outside the galactic bulge.

For illustration, the long axis of the planet Mercury is defined as the line through its successive positions of perihelion and aphelion. Over time, the long axis of most orbiting bodies rotates gradually, generally no more than a few degrees per complete revolution, because of gravitational perturbations from other bodies, oblateness in the attracting body, general relativistic effects, and other effects. Newton's method uses this apsidal precession as a sensitive probe of the type of force being applied to the planets. Newton's theorem describes only the effects of adding an inverse-cube central force.

Charney earned his undergraduate and graduate degrees at UCLA, culminating in a Ph.D. in physics in 1946. His Ph.D. dissertation, titled “The Dynamics of Long Waves in a Baroclinic Westerly Current” comprised the entire October 1947 issue of the Journal of Meteorology. The paper was influential because it emphasized the influence of “long waves” in the upper atmosphere on the behavior of the entire atmosphere rather than the more traditional emphasis on the polar front and also provided a way of analyzing perturbations along these waves that was both physically insightful and mathematically rigorous.

Microwave ovens in residences dominate the 2.4 GHz band and will cause "meal time perturbations" of the noise floor. There are many other sources of interference that aggregate into a formidable obstacle to enabling long-range use in occupied areas. Residential wireless phones, USB 3.0 Hubs, baby monitors, wireless cameras, remote car starters, and Bluetooth products are all capable of transmitting in the 2.4 GHz band. Due to the intended nature of the 2.4 GHz band, there are many users of this band, with potentially dozens of devices per household.

Near the sonic speed M_\infty \simeq 1 the PG transformation features a singularity. The singularity is also called the Prandtl–Glauert singularity, and the flow resistance is calculated to approach infinity. In reality, aerodynamic and thermodynamic perturbations get amplified strongly near the sonic speed, but a singularity does not occur. An explanation for this is that the linearized small-disturbance potential equation above is not valid, since it assumes that there are only small variations in Mach number within the flow and absence of compression shocks and thus is missing certain nonlinear terms.

The importance of m6A methylation for physiological processes was recently demonstrated. Inhibition of m6A methylation via pharmacological inhibition of cellular methylations or more specifically by siRNA-mediated silencing of the m6A methylase Mettl3 led to the elongation of the circadian period. In contrast, overexpression of Mettl3 led to a shorter period. The mammalian circadian clock, composed of a transcription feedback loop tightly regulated to oscillate with a period of about 24 hours, is therefore extremely sensitive to perturbations in m6A-dependent RNA processing, likely due to the presence of m6A sites within clock gene transcripts.

Gravitational collapse requires great density. In the current epoch of the universe these high densities are found only in stars, but in the early universe shortly after the Big Bang densities were much greater, possibly allowing for the creation of black holes. High density alone is not enough to allow black hole formation since a uniform mass distribution will not allow the mass to bunch up. In order for primordial black holes to have formed in such a dense medium, there must have been initial density perturbations that could then grow under their own gravity.

Three of the four pressure gauges and both electrostatic probes operated normally. One spectrometer malfunctioned, and the other operated intermittently. The successful launch and operating of Explorer 17 allowed scientists for the first time to obtain instantaneous atmospheric density measurements using several independent measuring systems, to measure the atmosphere during a single day under nearly constant local time conditions and geomagnetic activity, and to compare direct measurements of density with those inferred from measurements of perturbations in the satellite period orbit. The spacecraft decayed from orbit after 1,325 days on November 24, 1966.

Scientists study photon diffusion damping (and CMB anisotropies in general) because of the insight the subject provides into the question, "How did the universe come to be?". Specifically, primordial anisotropies in the temperature and density of the universe are supposed to be the causes of later large-scale structure formation. Thus it was the amplification of small perturbations in the pre- recombination universe that grew into the galaxies and galaxy clusters of the present era. Diffusion damping made the universe isotropic within distances on the order of the Silk Scale.

The glass forms include borosilicate glasses and phosphate glasses. Borosilicate nuclear waste glasses are used on an industrial scale to immobilize high level radioactive waste in many countries which are producers of nuclear energy or have nuclear weaponry. The glass waste forms have the advantage of being able to accommodate a wide variety of waste-stream compositions, they are easy to scale up to industrial processing, and they are stable against thermal, radiative, and chemical perturbations. These glasses function by binding radioactive elements to nonradioactive glass-forming elements.

GPS compasses share the main advantages of gyrocompasses. They determine true North, as opposed to magnetic North, and they are unaffected by perturbations of the Earth's magnetic field. Additionally, compared with gyrocompasses, they are much cheaper, they work better in polar regions, they are less prone to be affected by mechanical vibration, and they can be initialized far more quickly. However, they depend on the functioning of, and communication with, the GPS satellites, which might be disrupted by an electronic attack or by the effects of a severe solar storm.

When a system containing a plasma is at equilibrium, it is possible for certain parts of the plasma to be disturbed by small perturbative forces acting on it. The stability of the system determines if the perturbations will grow, oscillate, or be damped out. In many cases, a plasma can be treated as a fluid and its stability analyzed with magnetohydrodynamics (MHD). MHD theory is the simplest representation of a plasma, so MHD stability is a necessity for stable devices to be used for nuclear fusion, specifically magnetic fusion energy.

During magnetisation of a magnet; the external field is the applied electric field, the neighbour component is the effect of localised magnetic fields of the dipoles and the random component represents other perturbations from external or internal stimuli. There are many practical applications to this, a manufacturer can use this type of simulation to non- destructively test their magnets to see how it responds under certain conditions. To test its magnetisation after taking a large force i.e. a hammer blow or dropping it on the floor, one could suddenly increase the external force (H) or the coupling constant (J).

Kepler-80 d, e, b, c and g have orbits locked in a resonance. While their periods are in a ~ 1.000: 1.512: 2.296: 3.100: 4.767 ratio, in a frame of reference that rotates with the conjunctions this reduces to a ratio of 4:6:9:12:18. Conjunctions of d and e, e and b, b and c, and c and g occur at relative intervals of 2:3:6:6 in a pattern that repeats about every 191 days. Librations of possible three-body resonances have amplitudes of only about 3 degrees, and modeling indicates the resonant system is stable to perturbations.

Like most toroidal confinement schemes, the RFP relies on a transient burst of current to create the plasma and the magnetic fields that confine it. But for the RFP to be a viable fusion energy candidate the plasma must be sustained by a steady state current source. OFCD is a scheme for driving a steady current in a relaxed plasma by adding sizable oscillating perturbations to the toroidal and poloidal fields injecting both power and helicity into the plasma. A nonlinear reaction in the plasma combines the two oscillations in such a way that, on average, a steady current is maintained.

Electrochemical noise (ECN) is the generic term given to fluctuations of current and potential. When associated with corrosion, it is the result of stochastic pulses of current generated by sudden film rupture, crack propagation, discrete events involving metal dissolution and hydrogen discharge with gas bubble formation and detachment. The technique of measuring electrochemical noise uses no applied external signal for the collection of experimental data. The ECN technique measures the signal perturbations which are low level fluctuations of the corrosion potential between two nominally identical electrodes which can be used in the mechanistic determination of corrosion type and speed.

Kalypso (minor planet designation: 53 Kalypso) is a large and very dark main belt asteroid that was discovered by German astronomer Robert Luther on April 4, 1858, at Düsseldorf. It is named after Calypso, a sea nymph in Greek mythology, a name it shares with Calypso, a moon of Saturn. The orbit of 53 Kalypso places it in a mean motion resonance with the planets Jupiter and Saturn. The computed Lyapunov time for this asteroid is 19,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets.

After orbits are determined, mathematical propagation techniques can be used to predict the future positions of orbiting objects. As time goes by, the actual path of an orbiting object tends to diverge from the predicted path (especially if the object is subject to difficult-to-predict perturbations such as atmospheric drag), and a new orbit determination using new observations serves to re-calibrate knowledge of the orbit. Satellite tracking is another major application. For the US and partner countries, to the extent that optical and radar resources allow, the Joint Space Operations Center gathers observations of all objects in Earth orbit.

Using this, the real gravitational binding energy of Earth can be calculated numerically as U = . According to the virial theorem, the gravitational binding energy of a star is about two times its internal thermal energy in order for hydrostatic equilibrium to be maintained. As the gas in a star becomes more relativistic, the gravitational binding energy required for hydrostatic equilibrium approaches zero and the star becomes unstable (highly sensitive to perturbations), which may lead to a supernova in the case of a high-mass star due to strong radiation pressure or to a black hole in the case of a neutron star.

The non equilibrium thermodynamics has been applied for explaining how ordered structures e.g. the biological systems, can develop from disorder. Even if Onsager's relations are utilized, the classical principles of equilibrium in thermodynamics still show that linear systems close to equilibrium always develop into states of disorder which are stable to perturbations and cannot explain the occurrence of ordered structures. Prigogine called these systems dissipative systems, because they are formed and maintained by the dissipative processes which take place because of the exchange of energy between the system and its environment and because they disappear if that exchange ceases.

In more precise terms, the Hill sphere approximates the gravitational sphere of influence of a smaller body in the face of perturbations from a more massive body. It was defined by the American astronomer George William Hill, based on the work of the French astronomer Édouard Roche. For this reason, it is also known as the "Roche sphere" (not to be confused with the Roche limit or Roche Lobe). In the example to the right, Earth's Hill sphere extends between the Lagrangian points and , which lie along the line of centers of the two bodies (the Earth and the Sun).

Catastrophe theory analyzes degenerate critical points of the potential function — points where not just the first derivative, but one or more higher derivatives of the potential function are also zero. These are called the germs of the catastrophe geometries. The degeneracy of these critical points can be unfolded by expanding the potential function as a Taylor series in small perturbations of the parameters. When the degenerate points are not merely accidental, but are structurally stable, the degenerate points exist as organising centres for particular geometric structures of lower degeneracy, with critical features in the parameter space around them.

Orbits of (blue), (green), and Neptune (grey) Orbits of (blue), (green), and Neptune (grey) The adjacent diagrams show polar and ecliptic views of the orbits of the two cubewanos. The perihelia (q) and the aphelia (Q) are marked with the dates of passage. The present positions (as of April 2006) are marked with the spheres, illustrating relative sizes and differences in albedo (both objects appear neutral in the visible spectrum). is classified as a classical Kuiper belt object and follows an orbit very similar to that of : highly inclined (26°) and moderately eccentric (e ~0.12), far from Neptune's perturbations (perihelion at ~37 AU).

A well-known classification of cellular automata by Stephen Wolfram studies their behavior on random initial conditions. For a reversible cellular automaton, if the initial configuration is chosen uniformly at random among all possible configurations, then that same uniform randomness continues to hold for all subsequent states. Thus it would appear that most reversible cellular automata are of Wolfram's Class 3: automata in which almost all initial configurations evolve pseudo-randomly or chaotically. However, it is still possible to distinguish among different reversible cellular automata by analyzing the effect of local perturbations on the behavior of the automaton.

The azide group is particularly bioorthogonal because it is extremely small (favorable for cell permeability and avoids perturbations), metabolically stable, and does not naturally exist in cells and thus has no competing biological side reactions. Although azides are not the most reactive 1,3-dipole available for reaction, they are preferred for their relative lack of side reactions and stability in typical synthetic conditions. The alkyne is not as small, but it still has the stability and orthogonality necessary for in vivo labeling. Cyclooctynes are traditionally the most common cycloalkyne for labeling studies, as they are the smallest stable alkyne ring.

However, he realized that his equations permitted the introduction of a constant term which could counteract the attractive force of gravity on the cosmic scale. Einstein published his first paper on relativistic cosmology in 1917, in which he added this cosmological constant to his field equations in order to force them to model a static universe. The Einstein model describes a static universe; space is finite and unbounded (analogous to the surface of a sphere, which has a finite area but no edges). However, this so-called Einstein model is unstable to small perturbations—it will eventually start to expand or contract.

If the black hole is rotating, there is a second radius of influence associated with the rotation. This is the radius inside of which the Lense-Thirring torques from the black hole are larger than the Newtonian torques between stars. Inside the rotational influence sphere, stellar orbits precess at approximately the Lense-Thirring rate; while outside this sphere, orbits evolve predominantly in response to perturbations from stars on other orbits. Assuming that the Milky Way black hole is maximally rotating, its rotational influence radius is about 0.001 parsec, while its radius of gravitational influence is about 3 parsecs.

However, is not a plutino, as it is not actually in a resonance with Neptune, and it may have formed near its present nearly circular orbit lying almost perfectly on the ecliptic. This TNO may have remained dynamically cold since its formation, and thus its orbit may not have been a direct result of significant perturbations from Neptune during its migration to the outer solar system. The Deep Ecliptic Survey (DES) currently classifies it as a cubewano (classical) based on a 10-million-year integration of the orbit. File:2002KX14-orbit.png comes to opposition in late May at an apparent magnitude of 20.4.

Modern experimental approaches using systems biology have identified many novel components in biological clocks that suggest an integrative view on how organisms maintain circadian oscillation. Recently, Baggs et al. developed a novel strategy termed "Gene Dosage Network Analysis" (GDNA) to describe network features in the human circadian clock that contribute to an organism's robustness against genetic perturbations. In their study, the authors used small interfering RNA (siRNA) to induce dose-dependent changes in gene expression of clock components within immortalized human osteosarcoma U2OS cells in order to build gene association networks consistent with known biochemical constraints in the mammalian circadian clock.

It is hypothesized by some researchers, such as Barabási, that the prevalence of small world networks in biological systems may reflect an evolutionary advantage of such an architecture. One possibility is that small-world networks are more robust to perturbations than other network architectures. If this were the case, it would provide an advantage to biological systems that are subject to damage by mutation or viral infection. In a small world network with a degree distribution following a power-law, deletion of a random node rarely causes a dramatic increase in mean-shortest path length (or a dramatic decrease in the clustering coefficient).

This can be observed annually when northern hub airports, such as Chicago's O'Hare airport, are shut down because of snow; many people have to take additional flights. By contrast, in a random network, in which all nodes have roughly the same number of connections, deleting a random node is likely to increase the mean-shortest path length slightly but significantly for almost any node deleted. In this sense, random networks are vulnerable to random perturbations, whereas small-world networks are robust. However, small-world networks are vulnerable to targeted attack of hubs, whereas random networks cannot be targeted for catastrophic failure.

Dark matter plays a crucial role in structure formation because it feels only the force of gravity: the gravitational Jeans instability which allows compact structures to form is not opposed by any force, such as radiation pressure. As a result, dark matter begins to collapse into a complex network of dark matter halos well before ordinary matter, which is impeded by pressure forces. Without dark matter, the epoch of galaxy formation would occur substantially later in the universe than is observed. The physics of structure formation in this epoch is particularly simple, as dark matter perturbations with different wavelengths evolve independently.

In some cases the coordination of motor components is hard-wired, consisting of fixed neuromuscular pathways that are called reflexes. Reflexes are typically characterized as automatic and fixed motor responses, and they occur on a much faster time scale than what is possible for reactions that depend on perceptual processing. Reflexes play a fundamental role in stabilizing the motor system, providing almost immediate compensation for small perturbations and maintaining fixed execution patterns. Some reflex loops are routed solely through the spinal cord without receiving input from the brain, and thus do not require attention or conscious control.

Computer simulations suggest that the original asteroid belt may have contained the mass equivalent to the Earth. Primarily because of gravitational perturbations, most of the material was ejected from the belt within about 1 million years of formation, leaving behind less than 0.1% of the original mass. Since their formation, the size distribution of the asteroid belt has remained relatively stable: there has been no significant increase or decrease in the typical dimensions of the main-belt asteroids. The 4:1 orbital resonance with Jupiter, at a radius 2.06 AU, can be considered the inner boundary of the asteroid belt.

Pallas has been observed occulting stars several times, including the best-observed of all asteroid occultation events, by 140 observers on 29 May 1983. These measurements resulted in the first accurate calculation of its diameter. After an occultation on 29 May 1979, the discovery of a possible tiny satellite with a diameter of about 1 km was reported, which was never confirmed. Radio signals from spacecraft in orbit around Mars and/or on its surface have been used to estimate the mass of Pallas from the tiny perturbations induced by it onto the motion of Mars.

The major components of the plan include the use of predictive, high- throughput cell-based assays (of human origin) to evaluate perturbations in key toxicity pathways, and to conduct targeted testing against those pathways. This approach will greatly accelerate our ability to test the vast "storehouses" of chemical compounds using a rational, risk-based approach to chemical prioritization, and provide test results that are hopefully far more predictive of human toxicity than current methods. Although a number of toxicity pathways have already been identified, most are only partially known and no common annotation exists. Mapping the entirety of these pathways (i.e.

The waves are sourced by primordial density perturbations, and travel at speed that can be predicted from the baryon density and other cosmological parameters. The total distance that these sound waves can travel before recombination determines a fixed scale, which simply expands with the universe after recombination. BAO therefore provide a standard ruler that can be measured in galaxy surveys from the effect of baryons on the clustering of galaxies. The method requires an extensive galaxy survey in order to make this scale visible, but has been measured with percent-level precision (see baryon acoustic oscillations).

Info-gap decision theory is a non-probabilistic decision theory that seeks to optimize robustness to failure – or opportuneness for windfall – under severe uncertainty,Yakov Ben-Haim, Information-Gap Theory: Decisions Under Severe Uncertainty, Academic Press, London, 2001.Yakov Ben-Haim, Info-Gap Theory: Decisions Under Severe Uncertainty, 2nd edition, Academic Press, London, 2006. in particular applying sensitivity analysis of the stability radius type to perturbations in the value of a given estimate of the parameter of interest. It has some connections with Wald's maximin model; some authors distinguish them, others consider them instances of the same principle.

Richard Muller's most recent paper relevant to the Nemesis theory was published in 2002. In 2002, Muller speculated that Nemesis was perturbed 400 million years ago by a passing star from a circular orbit into an orbit with an eccentricity of 0.7. In 2010, and again in 2013, Melott & Bambach found evidence for a signal showing an excess extinction rate with a 27-million-year periodicity. However, because Nemesis is so distant from the Sun, it is expected to be subject to perturbations by passing stars, and therefore its orbital period should shift by 15–30%.

Based on an analysis of data from a 2400 deg2 primary observing patch (roughly 6% of the full sky), the ABS experiment measured the expected polarization of the CMB from density perturbations in the early universe, but found no evidence for a GWB from inflation. The ABS experiment also demonstrated the ability to use a half-wave plate as a fast, front-end polarization modulator for measurement stability and control of systematic errors. The ABS project was supported by funding from the NSF, NASA, and CONICYT. Major collaborating institutions included Princeton University, the Johns Hopkins University, NIST, and the Universidad de Chile.

Anna Maria Nobili is an Italian physicist active in the field of gravitational physics. Her institution is Pisa University. She authored a number of papers on satellite dynamics and co-authored a book with Andrea Milani and P. Farinella on the orbital perturbations induced by non-gravitational forces. After having published several papers on celestial mechanics, also in collaboration with Clifford Will and E. Myles Standish, Nobili is now Principal Investigator of the Galileo Galilei (GG) experiment aimed to improve the accuracy of the equivalence principle lying at the foundation of general relativity and of other metric theories of gravity.

Galatea's orbit lies below Neptune's synchronous orbit radius, so it is slowly spiralling inward due to tidal deceleration and may eventually impact the planet or break up into a new planetary ring system upon passing its Roche limit due to tidal stretching. Galatea appears to be a shepherd moon for the Adams ring that is outside its orbit. Resonances with Galatea in the ratio 42:43 are also considered the most likely mechanism for confining the unique ring arcs that exist in this ring. Galatea's mass has been estimated based on the radial perturbations it induces on the ring.

The focus of the Carpenter lab turned towards machine learning by 2009, and later deep learning, to identify biological structures of interest and to identify patterns resulting from chemical or genetic perturbations to identify cures for diseases. She was an early pioneer of the new field of image-based profiling, which is related to gene expression profiling but uses microscopy images as the data source. Together with Stuart Schreiber, the Carpenter laboratory invented the Cell Painting assay, which is the most widely used for this purpose. Carpenter's CellProfiler software and Cell Painting assay formed the initial scientific platform for Recursion Pharmaceuticals.

This effect might be somewhat mitigated by the fact that objects of and above might excite eccentric perturbations in the disk, allowing for non-negligible mass accretion even in the presence of a gap. Objects that form further outside (a>80 AU), where the disk is prone to gravitational instabilities, might be able to reach the masses required to cross the planet–brown dwarf threshold. For these objects it might be unlikely to migrate into the inner regions of the disk, however, due to the long type- II migration timescale for massive objects in the brown dwarf mass regime.

The E-modes arise naturally from Thomson scattering in a heterogeneous plasma. The B-modes are not produced by standard scalar type perturbations. Instead they can be created by two mechanisms: the first one is by gravitational lensing of E-modes, which has been measured by the South Pole Telescope in 2013; the second one is from gravitational waves arising from cosmic inflation. Detecting the B-modes is extremely difficult, particularly as the degree of foreground contamination is unknown, and the weak gravitational lensing signal mixes the relatively strong E-mode signal with the B-mode signal.

Petroleum oil is toxic for most life forms and episodic and chronic pollution of the environment by oil causes major ecological perturbations. Marine environments are especially vulnerable, since oil spills of coastal regions and the open sea are poorly containable and mitigation is difficult. In addition to pollution through human activities, millions of tons of petroleum enter the marine environment every year from natural seepages. Despite its toxicity, a considerable fraction of petroleum oil entering marine systems is eliminated by the hydrocarbon- degrading activities of microbial communities, in particular by a remarkable recently discovered group of specialists, the so-called hydrocarbonoclastic bacteria (HCB).

An initial postural reaction on exposure to an external perturbations was shown to be generated by the brainstem and spinal cord in animal and human studies (short latency mono or polysynaptic spinal loop 40-65ms) Bove, M., Nardone, A., & Schieppati, M. (2003). Effects of leg muscle tendon vibration on group Ia and group II reflex responses to stance perturbation in humans. J Physiol, 550(Pt 2), 617-630. doi:10.1113/jphysiol.2003.043331 followed by the later part of the reaction which is modified by direct transcortical loops (long latency loops, ~132ms).Ackermann, H., Diener, H. C., & Dichgans, J. (1987).

The model is run thousands of times with slight perturbations to various physics parameters (a 'large ensemble') and the project examines how the model output changes. These parameters are not known exactly, and the variations are within what is subjectively considered to be a plausible range. This will allow the project to improve understanding of how sensitive the models are to small changes and also to things like changes in carbon dioxide and sulphur cycle. In the past, estimates of climate change have had to be made using one or, at best, a very small ensemble (tens rather than thousands) of model runs.

In orbital mechanics, a frozen orbit is an orbit for an artificial satellite in which natural drifting due to the central body's shape has been minimized by careful selection of the orbital parameters. Typically, this is an orbit in which, over a long period of time, the satellite's altitude remains constant at the same point in each orbit. Changes in the inclination, position of the lowest point of the orbit, and eccentricity have been minimized by choosing initial values so that their perturbations cancel out. This results in a long- term stable orbit that minimizes the use of station-keeping propellant.

The resulting beam has a larger diameter, and hence a lower divergence. Divergence of a laser beam may be reduced below the diffraction of a Gaussian beam or even reversed to convergence if the refractive index of the propagation media increases with the light intensity. This may result in a self-focusing effect. When the wave front of the emitted beam has perturbations, only the transverse coherence length (where the wave front perturbation is less than 1/4 of the wavelength) should be considered as a Gaussian beam diameter when determining the divergence of the laser beam.

For scientific uses, a modern planetary ephemeris comprises software that generates positions of planets and often of their satellites, asteroids, or comets, at virtually any time desired by the user. Typically, such ephemerides cover several centuries, past and future; the future ones can be covered because the field of celestial mechanics has developed several accurate theories. Nevertheless, there are secular phenomena which cannot adequately be considered by ephemerides. The greatest uncertainties in the positions of planets are caused by the perturbations of numerous asteroids, most of whose masses and orbits are poorly known, rendering their effect uncertain.

Over time the differences in the dynamics grow from almost unnoticeable to drastic. In chaos theory, the butterfly effect is the sensitive dependence on initial conditions in which a small change in one state of a deterministic nonlinear system can result in large differences in a later state. The term butterfly effect is closely associated with the work of Edward Lorenz. It is derived from the metaphorical example of the details of a tornado (the exact time of formation, the exact path taken) being influenced by minor perturbations such as a distant butterfly flapping its wings several weeks earlier.

The microdialysis technique has undergone much development since its first use in 1972, when it was first employed to monitor concentrations of endogenous biomolecules in the brain. Today's area of application has expanded to monitoring free concentrations of endogenous as well as exogenous compounds in virtually any tissue. Although microdialysis is still primarily used in preclinical animal studies (e.g. laboratory rodents, dogs, sheep, pigs), it is now increasingly employed in humans to monitor free, unbound drug tissue concentrations as well as interstitial concentrations of regulatory cytokines and metabolites in response to homeostatic perturbations such as feeding and/or exercise.

A supernova explosion at a distance of 26 light years will reduce the ozone column density by half. On average, a supernova explosion occurs within 32 light years once every few hundred million years, resulting in a depletion of the ozone layer lasting several centuries. Over the next two billion years, there will be about 20 supernova explosions and one gamma ray burst that will have a significant impact on the planet's biosphere. The incremental effect of gravitational perturbations between the planets causes the inner Solar System as a whole to behave chaotically over long time periods.

Recent scientific analysis no longer supports the idea that extinctions on Earth happen at regular, repeating intervals. Thus, the Nemesis hypothesis is no longer needed to explain current assumptions. A somewhat similar hypothesis was advanced by astronomer John J. Matese of the University of Louisiana at Lafayette in 2002. He contends that more comets are arriving in the inner Solar System from a particular region of the postulated Oort cloud than can be explained by the galactic tide or stellar perturbations alone, and that the most likely cause would be a Jupiter-mass object in a distant orbit.

The long-term orbits of comets are difficult to calculate because of errors in the known trajectory that accumulate with perturbations from the planets, and in the days before electronic computers some people dedicated their entire careers to this. Even so, quite a few comets were lost because their orbits are also affected by non-gravitational effects such as the release of gas and other material that forms the comet's coma and tail. Unlike a long-period comet, the next perihelion passage of a numbered periodic comet can be predicted with a high degree of accuracy.

Wolfram argues that one of his achievements is in providing a coherent system of ideas that justifies computation as an organizing principle of science. For instance, he argues that the concept of computational irreducibility (that some complex computations are not amenable to short-cuts and cannot be "reduced"), is ultimately the reason why computational models of nature must be considered in addition to traditional mathematical models. Likewise, his idea of intrinsic randomness generation—that natural systems can generate their own randomness, rather than using chaos theory or stochastic perturbations—implies that computational models do not need to include explicit randomness.

The 250-680 nm spectral domain is used for the determination of O3, NO2, NO3−, aerosols and temperature. In addition, two high spectral resolution channels centred at 760 and 940 nm allow measurements of O2 and H2O and two fast photometers are used to correct star scintillation perturbations and to determine high vertical resolution temperature profiles. Global latitude coverage is obtained with up to 40 stellar occultations per orbit from South Pole to North Pole. Data acquired on dark limb (night-time) are of better quality than on bright limb (day-time) because of a smaller perturbation by background light.

In ecology, the theory of alternative stable states (sometimes termed alternate stable states or alternative stable equilibria) predicts that ecosystems can exist under multiple "states" (sets of unique biotic and abiotic conditions). These alternative states are non-transitory and therefore considered stable over ecologically-relevant timescales. Ecosystems may transition from one stable state to another, in what is known as a state shift (sometimes termed a phase shift or regime shift), when perturbed. Due to ecological feedbacks, ecosystems display resistance to state shifts and therefore tend to remain in one state unless perturbations are large enough.

Furthermore, it has the ability to electrolocate by analyzing the perturbations in its electric field. However, when the frequency of a neighboring fish's current is very close (less than 20 Hz difference) to that of its own, the fish will avoid having their signals interfere through a behavior known as Jamming Avoidance Response. If the neighbor's frequency is higher than the fish's discharge frequency, the fish will lower its frequency, and vice versa. The sign of the frequency difference is determined by analyzing the "beat" pattern of the incoming interference which consists of the combination of the two fish's discharge patterns.

Established plants cannot move away from perturbations, and will eventually die if their habitat is contaminated by heavy metals or metalloids at a concentration that is too elevated for their physiology. Some species are more resistant and will survive these levels, and some non-native species that can tolerate these concentrations in the soil, will migrate in the surrounding lands of the mine to occupy the ecological niche. Plants can be affected through direct poisoning, for example arsenic soil content reduces bryophyte diversity. Soil acidification through pH diminution by chemical contamination can also lead to a diminished species number.

Matjaž Perc is one of the foremost experts of the theory of cooperation on networks. He has applied Monte Carlo simulations and dynamical mean field theory to discover that stochastic perturbations resolve social dilemmas in a resonance-like manner. He has also pioneered self-organization as a way of stabilizing reward and punishment in structured populations, and he has proposed the introduction of discrete strategies in ultimatum games, which has contributed to the understanding of the fascinating complexity behind human bargaining. His research has helped to reveal the full potential of methods of non-equilibrium statistical physics in evolutionary game theory.

Murtazin was born in the village Aznash in Uchalinsky District, now in Bashkortostan. He graduated from the Department of Mathematics of Bashkir State University and defended his doctoral thesis in 1994. Since 1978 until the present day he is the head of the Mathematical Analysis chair of the department Scientific activity is devoted to problems of quantum mechanics. Murtazin investigated the asymptotic behavior of the discrete spectrum of the Schrödinger operator, the spectrum of perturbations of partial differential operators, results on the two-particle operators in the class of integrable potentials, conditions for the existence of virtual particles 4.

Scott's primary research focus is on the ionosphere, particularly perturbations from below by atmospheric phenomenon. Scott was the first scientist to demonstrate lightning effects on the 'sporadic E' layer; transient, localized patches of relatively high electron density in the mid-ionosphere, which significantly affect radio-wave propagation. He subsequently investigated the relation between lightning occurrence and magnetic structures in the solar wind. Scott has also used novel datasets to study how pressure waves from the lower atmosphere can lead to disturbances in the ionosphere, most notably using records of the London Blitz World War II bombing raids and ionospheric measurements from Slough.

The existence of a topological defect can be demonstrated whenever the boundary conditions entail the existence of homotopically distinct solutions. Typically, this occurs because the boundary on which the conditions are specified has a non-trivial homotopy group which is preserved in differential equations; the solutions to the differential equations are then topologically distinct, and are classified by their homotopy class. Topological defects are not only stable against small perturbations, but cannot decay or be undone or be de-tangled, precisely because there is no continuous transformation that will map them (homotopically) to a uniform or "trivial" solution.

A woman demonstrating the ability to balance A waiter balancing wine glasses Balance in biomechanics, is an ability to maintain the line of gravity (vertical line from centre of mass) of a body within the base of support with minimal postural sway. Sway is the horizontal movement of the centre of gravity even when a person is standing still. A certain amount of sway is essential and inevitable due to small perturbations within the body (e.g., breathing, shifting body weight from one foot to the other or from forefoot to rearfoot) or from external triggers (e.g.

In vivo studies (repeat-dose toxicology in laboratory animals, target animal safety, field studies) provided by MERIAL, the company that produces afoxolaner-derivative medicines, did not show evidence of neurological or behavioural effects suggestive of GABA-mediated perturbations in mammals. The Committee for Medicinal Products for Veterinary Use (CVMP) therefore concluded that binding to dog, rat or human GABA receptors is expected to be low for afoxolaner. Selectivity for insect over mammalian GABA- receptors has been demonstrated for other isoxazolines. The selectivity might be explained by the number of pharmacological differences that exist between GABA-gated chloride channels of insects and vertebrates.

Patterns can include relatively evenly spaced patches, parallel bands or some intermediate between those two. These patterns in the vegetation can appear without any underlying pattern in soil types, and are thus said to “self-organize” rather than be determined by the environment. Several of the mechanisms underlying patterning of vegetation have been known and studied since at least the middle of the 20th century, however, mathematical models replicating them have only been produced much more recently. Self-organization in spatial patterns is often a result of spatially uniform states becoming unstable through the monotonic growth and amplification of nonuniform perturbations.

A normally hyperbolic invariant manifold (NHIM) is a natural generalization of a hyperbolic fixed point and a hyperbolic set. The difference can be described heuristically as follows: For a manifold \Lambda to be normally hyperbolic we are allowed to assume that the dynamics of \Lambda itself is neutral compared with the dynamics nearby, which is not allowed for a hyperbolic set. NHIMs were introduced by Neil Fenichel in 1972. In this and subsequent papers, Fenichel proves that NHIMs possess stable and unstable manifolds and more importantly, NHIMs and their stable and unstable manifolds persist under small perturbations.

LAEs are important probes of reionization, cosmology (BAO), and they allow probing of the faint end of the luminosity function at high redshift. The baryonic acoustic oscillation signal should be evident in the power spectrum of Lyman-alpha emitters at high redshift. Constraining Cosmology with Lyman-alpha Emitters a Study Using HETDEX Parameters Baryonic acoustic oscillations are imprints of sound waves on scales where radiation pressure stabilized the density perturbations against gravitational collapse in the early universe. The three- dimensional distribution of the characteristically homogeneous Lyman-alpha galaxy population will allow a robust probe of cosmology.

Most perceptions of heartbeat sensations usually occur during a time of homeostatic perturbation, such as when the state of the body changes from external or internal influences such as physical exertion or elevated arousal states (e.g., riding a roller coaster, watching a scary movie, public speaking anxiety, or having a panic attack). For this reason, cardiac interoception is also sometimes studied by inducing perturbations of bodily state. This can be done pharmacologically using adrenaline-like drugs, such as isoproterenol, which mimics activation of the sympathetic nervous system, resulting in increased heart rate and respiration rate, similar to the “fight-or-flight” response.

Temperature and pain are thought to be represented as “feelings” of coolness/warmness and pleasantness/unpleasantness in the brain. These sensory and affective characteristics of thermoregulation may motivate certain behavioral responses depending on the state of the body (for example, moving away from a source of heat to a cooler space). Such perturbations in the internal homeostatic environment of an organism are thought to be key aspects of a motivational process giving rise to emotional states, and have been proposed to be represented principally by the insular cortex as feelings. These feelings then influence drives when the anterior cingulate cortex is activated.

All of these factors are leading to the decline of this species. Sycamore is barely within the range of the tolerations of Sonora chubs, therefore it has been completely isolated to these waters, and if forced out, it will have nowhere to recover (Hendrickson and Juarez – Romero 1990). These various human perturbations are being made worse by decreased watershed conditions and increasing drought conditions, and could ultimately lead to the extirpation of the species. There is also a concern for predation by non-native green sunfish, as is the case with the majority of Arizona fish on the endangered list.

Gravitational stirring by embryos during the instability could increase the number of asteroids entered unstable orbits, resulting in the loss of 99-99.9% of its mass. The sweeping of resonances and the penetration of the ice giant into the asteroid belt results in the dispersal of asteroid collisional families formed during or before the Late Heavy Bombardment. A collisional family's inclinations and eccentricities are dispersed due to the sweeping secular resonances, including those inside mean motion resonances, with the eccentricities being most affected. Perturbations by close encounters with the ice giant result in the spreading of a family's semi-major axes.

After Mars is scattered from the annulus by encounters with other planets it continues to have encounters with other objects until the planets clear material from the inner Solar System. While these encounters enable the orbit of Mars to become decoupled from the other planets and remain on a stable orbit, they can also perturb the disk of material from which the moons of Mars form. These perturbations cause material to escape from the orbit of Mars or to impact on its surface reducing the mass of the disk resulting in the formation of smaller moons.

The research interests of Prof. V. Koshmanenko concern modeling of complex dynamical systems, fractal geometry, functional analysis, operator theory, mathematical physics. He proposed the construction of wave and scattering operators in terms of bilinear functionals, introduced the notion of singular quadratic form and produced the classification of pure singular quadratic forms, developed the self-adjoint extensions approach to the singular perturbation theory in scales of Hilbert spaces, investigated the direct and inverse negative eigenvalues problem under singular perturbations. Volodymyr Koshmanenko developed the original theory of conflict dynamical systems and built a serious new models of complex dynamical systems with repulsive and attractive interaction.

171-2 Acoustic perturbations of initial density fluctuations in the universe made some regions of space hotter and denser than others.Harrison (1970-05-15) These differences in temperature and density are called anisotropies. Photons diffused from the hot, overdense regions of plasma to the cold, underdense ones: they dragged along the protons and electrons: the photons pushed electrons along, and these, in turn, pulled on protons by the Coulomb force. This caused the temperatures and densities of the hot and cold regions to be averaged and the universe became less anisotropic (characteristically various) and more isotropic (characteristically uniform).

During the late Cretaceous widespread conditions of oceanic anoxia occurred across the Cenomanian–Turonian (C-T) stage boundary between about 94.2 and 93.5 million years ago (Oceanic Anoxic Event II, OAE II). This Cenomanian–Turonian Boundary Event is reflected by one of the most extreme carbon cycle perturbations in Earth's history. Studies have been done on the marine reptiles to determine the impact of OAE II on the biodiversity of the group in the Western Interior Seaway. Results from that study seem to suggest that at least locally the OAE II had little to no effect on marine reptile diversity.

The first mathematical formulation of quasispecies was deterministic; it assumed steady state mutant distributions in genetic equilibrium without perturbations derived from modifications of the environment or population size. These conditions are common in initial theoretical formulations of complex phenomena because they confer mathematical tractability. Since then, several extensions of the theory to non-equilibrium conditions with stochastic components have been developed, with the aim of finding general solutions for multi-peak fitness landscapes. These objectives approximate quasispecies to the real case of RNA viruses, which are compelled to deal with dramatic variations in population size and environment.

The CISPR (Comité International Spécial des Perturbations Radioélectriques) – in English, the International Special Committee on Radio Interference – is one of the groups founded by the IEC. Currently, 86 countries are IEC members while another 87 participate in the Affiliate Country Programme, which is not a form of membership but is designed to help industrializing countries get involved with the IEC. Originally located in London, the Commission moved to its current headquarters in Geneva in 1948. It has regional centres in Africa (Nairobi, Kenya), Asia- Pacific (Singapore), Latin America (São Paulo, Brazil) and North America (Boston, United States).

Seventy percent of the Earth is covered by water, so information about the marine environment is vital in understanding how the Earth's surface system works. Nick McCave's research looks at perturbations in the deep oceans, using evidence from micro-fossils combined with carbon dating, to obtain information on pre-historical climate change. It is important to understand the normal cycles of climate change, in order to assess the degree to which the global warming we are experiencing now is caused by man, and the likely consequences by analysis of past analogues. One problem is the interaction between atmospheric climate change and the observed changes in the ocean currents.

Every force has a coupling constant, which is a measure of its strength, and determines the chances of one particle to emit or absorb another particle. For electromagnetism, the coupling constant is proportional to the square of the electric charge. When physicists study the quantum behavior of electromagnetism, they can't solve the whole theory exactly, because every particle may emit and absorb many other particles, which may also do the same, endlessly. So events of emission and absorption are considered as perturbations and are dealt with by a series of approximations, first assuming there is only one such event, then correcting the result for allowing two such events, etc.

In 2010, Gibson published a paper highlighting the effects of experimental "jet lag" on adult neurogenesis and cognition. To explore how circadian disruptions affect the brain, Gibson used a technique called experimental jet lag where she introduced phase advances in the light:dark cycle of female hamsters, similar to phase shifts one might experience when traveling to a new time zone. She found that experimental "jet lag" caused pronounced decreases in hippocampal cell proliferation and neurogenesis leading to notable deficits in learning and memory. Although the circadian perturbations disrupted the hypothalamic–pituitary–adrenal axis, the decreases in hippocampal cell proliferation and neurogenesis were not due to cortisol or stress hormones.

The main result of the theorem is that all the mixed strategy equilibria of a given game can be purified using the same sequence of perturbed games. However, in addition to independence of the perturbations, it relies on the set of payoffs for this sequence of games being of full measure. There are games, of a pathological nature, for which this condition fails to hold. The main problem with these games falls into one of two categories: (1) various mixed strategies of the game are purified by different sequences of perturbed games and (2) some mixed strategies of the game involve weakly dominated strategies.

When it was first discovered, it was quickly found that the object was in an orbit around Earth. Astronomers were surprised at this, as the Moon is the only large object in orbit around the Earth,Also believed to orbit the Earth are the Kordylewski clouds: large transient concentrations of dust at the Trojan points of the Earth–Moon system, discovered in 1956 by the Polish astronomer Kazimierz Kordylewski. and anything else would have been ejected long ago due to perturbations with the Earth, the Moon and the Sun. Therefore, it probably entered into Earth orbit very recently, yet there was no recently launched spacecraft that matched the orbit of J002E3.

Comet Daniel is a periodic comet in the solar system discovered by Zaccheus Daniel (Halsted Observatory, Princeton University, New Jersey, United States) on December 7, 1909, estimated as magnitude 9. Following its discovery, the returns for 1916, 1923, and 1930 were predicted but on each occasion it was not recovered. The 1937 return was recovered by Shin-ichi Shimizu (Simada, Japan) on January 31 after a calculation of the comet's orbit by Hidewo Hirose (Tokyo, Japan) after he took calculations for the 1923 return done by Alexander D. Dubiago and took into account perturbations from Jupiter. All returns apart from 1957 and 1971 have been recovered.

Planetary orbits are dynamically unstable within the cores of dense clusters because of the perturbations of passing stars. A planet orbiting at 1 astronomical unit around a star that is within the core of a dense cluster such as would only survive on the order of 108 years. There is a planetary system orbiting a pulsar (PSR B1620−26) that belongs to the globular cluster M 4, but these planets likely formed after the event that created the pulsar. Some globular clusters, like Omega Centauri in the Milky Way and G 1 in M 31, are extraordinarily massive, with several million solar masses () and multiple stellar populations.

This minor planet was named in honor of Russian astronomer Samuel Gdalevich Makover (1908–1970), who studied extensively the orbit of Encke's Comet (referred to as Comet Encke-Backlund in Russia), and pioneered in the use of electronic calculators for computing planetary perturbations and orbit improvements. He was head of the Institute of Theoretical Astrophysics's (ITA) department of minor planets and comets, and editor of the annual volume of Minor Planet Ephemerides. He was also a vice-president of IAU's commission 20, Positions & Motions of Minor Planets, Comets & Satellites, in the 1960s. The official was published by the Minor Planet Center on 25 September 1971 ().

The planetary problem is the -body problem in the case that one of the masses is much larger than all the others. A prototypical example of a planetary problem is the Sun–Jupiter–Saturn system, where the mass of the Sun is about 100 times larger than the masses of Jupiter or Saturn. An approximate solution to the problem is to decompose it into pairs of star–planet Kepler problems, treating interactions among the planets as perturbations. Perturbative approximation works well as long as there are no orbital resonances in the system, that is none of the ratios of unperturbed Kepler frequencies is a rational number.

In this formalism, a liquid crystal material is treated as a continuum; molecular details are entirely ignored. Rather, this theory considers perturbations to a presumed oriented sample. The distortions of the liquid crystal are commonly described by the Frank free energy density. One can identify three types of distortions that could occur in an oriented sample: (1) twists of the material, where neighboring molecules are forced to be angled with respect to one another, rather than aligned; (2) splay of the material, where bending occurs perpendicular to the director; and (3) bend of the material, where the distortion is parallel to the director and molecular axis.

The Darrieus–Landau instability is an intrinsic flame instability that occurs in premixed flames due to the thermal expansion of the gas produced by the combustion process. It was predicted independently by Georges Jean Marie Darrieus and Lev Landau. The instability analysis behind the Darrieus–Landau instability considers a planar, premixed flame front subjected to very small perturbations. It is useful to think of this arrangement as one in which the unperturbed flame is stationary, with the reactants (fuel and oxidizer) directed towards the flame and perpendicular to it with a velocity u1, and the burnt gases leaving the flame also in a perpendicular way but with velocity u2.

Ordinary shock waves are compressive, that is, they fulfill the Lax conditions: the characteristic speed (in air, the speed of sound) behind the shock is greater than that of the shock itself, which is greater than the characteristic speed in front of the shock. The characteristic speed is the speed of small, travelling perturbations. These conditions seem to be necessary for a shock wave to remain and not decay. If the peak of a wave moves faster than at its base, then the wave front becomes self-sharpening and eventually becomes a nearly discontinuous shock, a sharp wave front which remains so when it travels.

An important role for proprioception is to allow an animal to stabilize itself against perturbations. For instance, for a person to walk or stand upright, they must continuously monitor their posture and adjust muscle activity as needed to provide balance. Similarly, when walking on unfamiliar terrain or even tripping, the person must adjust the output of their muscles quickly based on estimated limb position and velocity. Proprioceptor reflex circuits are thought to play an important role to allow fast and unconscious execution of these behaviors, To make control of these behaviors efficient, proprioceptors are also thought to regulate reciprocal inhibition in muscles, leading to agonist-antagonist muscle pairs.

Typically, Taurids appear at a rate of about 5 per hour, moving slowly across the sky at about 28 kilometers per second (17 mi/s), or 100,800 km/h (65,000 mph). If larger than a pebble, these meteors may become bolides as bright as the Moon and leave behind smoke trails. Due to the gravitational perturbations of planets, especially Jupiter, the Taurids have spread out over time, allowing separate segments labeled the Northern Taurids (NTA) and Southern Taurids (STA) to become observable. The Southern Taurids are active from about September 10 to November 20, while the Northern Taurids are active from about October 20 to December 10.

The Leonids The great meteor shower of November 1866 turned his attention to the Leonids, whose probable path and period had already been discussed and predicted by Hubert Anson Newton in 1864. Newton had asserted that the longitude of the ascending node, that marked where the shower would occur, was increasing and the problem of explaining this variation attracted some of Europe's leading astronomers. Using a powerful and elaborate analysis, Adams ascertained that this cluster of meteors, which belongs to the Solar System, traverses an elongated ellipse in 33.25 years, and is subject to definite perturbations from the larger planets, Jupiter, Saturn, and Uranus. These results were published in 1867.

Brown's objective had been to produce an accurate ephemeris of the Moon, based purely on gravitational theory. For the 'main problem' of the Earth-Moon-Sun system, he calculated terms in longitude and latitude down to an uncertainty of 0.001 arcseconds. He also included perturbations due to the other planets (principally Jupiter and Venus) and also accounted for the more difficult problem of the non-spherical nature of the Earth and Moon. Observations showed that Brown's tables were indeed superior to those of Hansen, which had been in use since 1857, but there was still a large unexplained fluctuation in the Moon's mean longitude of the order of 10 arcseconds.

This formula includes about 200 km for the GEO-protected zone to also permit orbit maneuvers in GEO without interference with the graveyard orbit. Another of tolerance must be allowed for the effects of gravitational perturbations (primarily solar and lunar). The remaining part of the equation considers the effects of the solar radiation pressure, which depends on the physical parameters of the satellite. In order to obtain a license to provide telecommunications services in the United States, the Federal Communications Commission (FCC) requires all geostationary satellites launched after March 18, 2002, to commit to moving to a graveyard orbit at the end of their operational life.

Less efficient departure times from the same depot to the same destination exist before and after the well-aligned opportunity, but more research is required to show whether the efficiency falls off quickly or slowly. By contrast, launching directly in only one launch from the ground without orbital refueling or docking with another craft already on orbit offers daily launch opportunities though it requires larger and more expensive launchers. The restrictions on departure windows arise because low earth orbits are susceptible to significant perturbations; even over short periods they are subject to nodal regression and, less importantly, precession of perigee. Equatorial depots are more stable but also more difficult to reach.

Although TGF-β is important in regulating crucial cellular activities, only a few TGF-β activating pathways are currently known, and the full mechanism behind the suggested activation pathways is not yet well understood. Some of the known activating pathways are cell or tissue specific, while some are seen in multiple cell types and tissues. Proteases, integrins, pH, and reactive oxygen species are just few of the currently known factors that can activate TGF-β, as discussed below. It is well known that perturbations of these activating factors can lead to unregulated TGF-β signaling levels that may cause several complications including inflammation, autoimmune disorders, fibrosis, cancer and cataracts.

Changes resulting from astrogliosis are regulated in a context-specific manner by specific signaling events that have the potential to modify both the nature and degree of these changes. Under different conditions of stimulation, astrocytes can produce intercellular effector molecules that alter the expression of molecules in cellular activities of cell structure, energy metabolism, intracellular signaling, and membrane transporters and pumps. Reactive astrocytes respond according to different signals and impact neuronal function. Molecular mediators are released by neurons, microglia, oligodendrocyte lineage cells, endothelia, leukocytes, and other astrocytes in the CNS tissue in response to insults ranging from subtle cellular perturbations to intense tissue injury.

Peter Jenniskens predicted the 1995 return based on the hypothesis that these outbursts were caused by the dust trail of a long period comet occasionally wandering in Earth's path due to planetary perturbations. During observations in southern Spain, assisted by a team of observers of the Dutch Meteor Society, Jenniskens confirmed that the meteoroids were moving in a long-period comet orbit. The outburst of 1995 allowed researchers to determine the exact radiant of the swarm and the solar longitude of its peak as well as to confirm the brevity of Alpha Monocerotid outbursts as less than one hour. The parent body, probably a long-period comet, is unknown.

The first use of the Molniya orbit was by the communications satellite series of the same name. After two launch failures, and one satellite failure in 1964, the first successful satellite to use this orbit, Molniya 1-1, launched on 23 April 1965. The early Molniya-1 satellites were used for civilian television, telecommunication and long-range military communications, but they were also fitted with cameras used for weather monitoring, and possibly for assessing clear areas for Zenit spy satellites. The original Molniya satellites had a lifespan of approximately 1.5 years, as their orbits were disrupted by perturbations, and they had to be constantly replaced.

Konstantin Batygin's research is primarily aimed at understanding the formation and evolution of planetary systems. In 2010, Konstantin Batygin and David J. Stevenson published a calculation, which showed that hot Jupiters can become inflated as a consequence of Ohmic dissipation of electrical currents induced through an interaction between ionized atmospheric winds and the planetary magnetic field. In 2012, Batygin demonstrated that misalignments between stellar spin-axes and planetary orbits can arise from gravitational perturbations exerted onto protoplanetary disks by primordial companions stars. In 2015, Batygin and Laughlin hypothesized that the Solar System once possessed a population of short-period planets that were destroyed by Jupiter's migration through the solar nebula.

The transit-timing variation method (TTV) is one of two techniques, along with the transit-duration variation method, proposed in 2001 by astronomer Jordi Miralda-Escudé.Miralda-Escudé, Jordi (2001), "Orbital perturbations of transiting planets: A possible method to measure stellar quadrupoles and to detect Earth-mass planets", 2001 arXiv: 0104034; 2002 ApJ 564 1019. TTV was amplified upon in 2004 by astronomers Matthew J. Holman and Norman W. Murray;Holman, Matthew J.; and Murray, Norman W. (2004), "The Use of Transit Timing to Detect Extrasolar Planets with Masses as Small as Earth", 2004 arXiv: 0412028; 2005 Science 307 1288. and by Eric Agol, Jason Steffen, Re’em Sari, and Will Clarkson.

In late 2009, during the video presentation of “In Tune“ on Experty.by, it was announced that the band began work on a new album after perturbations in the line-up. In the spring of 2010 in an interview to the Chinese magazine , members of the band explained their approach to the thorough work, “Until recently, we just have not considered that it is necessary to record a full- length album, but now we are working hard in this direction.” The first single from the upcoming album entitled “Happy for a While“ was released in the Chinese market first with a special cover for the region on April 5, 2010.

Particle filters or Sequential Monte Carlo (SMC) methods are a set of Monte Carlo algorithms used to solve filtering problems arising in signal processing and Bayesian statistical inference. The filtering problem consists of estimating the internal states in dynamical systems when partial observations are made, and random perturbations are present in the sensors as well as in the dynamical system. The objective is to compute the posterior distributions of the states of some Markov process, given some noisy and partial observations. The term "particle filters" was first coined in 1996 by Del Moral in reference to mean field interacting particle methods used in fluid mechanics since the beginning of the 1960s.

Given the orbital eccentricity of this object, its orbital period is not a fixed value, because it is frequently perturbed by the gravity of the planets. Near perihelion, using an August 2011 epoch, Kazuo Kinoshita shows C/2010 X1 to have a heliocentric orbital period of 600,000 years, though more perturbations will occur. For objects at such high eccentricity, the Sun's barycentric coordinates are more stable than heliocentric coordinates. The orbit of a long-period comet is properly obtained when the osculating orbit is computed at an epoch after leaving the planetary region and is calculated with respect to the center of mass of the Solar System.

Interiors of Earth, Mars and the Moon (artist concept) The goals of the RISE experiment are to deduce the size and density of the Martian core through estimation of the precession and nutation of the spin axis. The precession and nutation estimates will be based on measurements of the relative velocity of the InSight lander and tracking stations on Earth known as the Deep Space Network. The perturbations resemble the wobble of a spinning top and occur on two time scales. The longer wobble, called precession, takes about 165,000 years and it is directly related to the mass and diameter of the iron-rich core.

As the nucleus is largely unaffected by the atomic shell, it is also intriguing to embed many nuclei into a crystal lattice environment. This concept is known as the crystal-lattice nuclear clock. Due to the high density of embedded nuclei of up to 1018 per cm3, this concept would allow to irradiate a huge amount of nuclei in parallel, thereby drastically increasing the achievable signal-to- noise ratio , however, on the cost of potentially higher external perturbations. It was also proposed to irradiate a metallic 229Th surface and to probe the isomer’s excitation in the internal conversion channel, which is known as the internal-conversion nuclear clock.

In these conditions of small sinusoidal perturbations with wavelength bigger than its perimeter, the cylinder surface area becomes larger than the one of unperturbed cylinder with the same volume and thus it becomes unstable. Later, Hove Hove, W., Ph.D. Dissertation, Friendlich-Wilhelms, Universitat zu Berlin (1887) formulated the variational requirements for the stability of axisymmetric capillary surfaces (unbounded) in absence of gravity and with disturbances constrained to constant volume. He first solved Young-Laplace equation for equilibrium shapes and showed that the Legendre condition for the second variation is always satisfied. Therefore, the stability is determined by the absence of negative eigenvalue of the linearized Young-Laplace equation.

The axis of this Laplace plane is coplanar with, and between, (a) the polar axis of the parent planet's spin, and (b) the orbital axis of the parent planet's orbit around the Sun. The Laplace plane arises because the equatorial oblateness of the parent planet tends to cause the orbit of the satellite to precess around the polar axis of the parent planet's equatorial plane, while the solar perturbations tend to cause the orbit of the satellite to precess around the polar axis of the parent planet's orbital plane around the Sun. The two effects acting together result in an intermediate position for the reference axis for the satellite orbit's precession.

The work of Harrison and of Soviet physicist Yakov Borisovich Zel'dovich on structure formation from primordial density perturbations in the cosmic plasma has led to the general use of the term Harrison-Zel'dovich spectrum for primordial random fluctuations characterised by a scale-invariant power spectrum. Harrison was fascinated with Olbers' Paradox (the night sky is dark despite the vast number of stars in the universe). In 1964, he published detailed calculations that solved the paradox by concluding that stars do not generate enough energy to illuminate the entire sky. In 1987, he published a book, Darkness at Night, mulling over the Paradox and its rich history.

The study of orbital motion and mathematical modeling of orbits began with the first attempts to predict planetary motions in the sky, although in ancient times the causes remained a mystery. Newton, at the time he formulated his laws of motion and of gravitation, applied them to the first analysis of perturbations, recognizing the complex difficulties of their calculation. Many of the great mathematicians since then have given attention to the various problems involved; throughout the 18th and 19th centuries there was demand for accurate tables of the position of the Moon and planets for purposes of navigation at sea. The complex motions of orbits can be broken down.

However, given that the comet nucleus is around 60 km in diameter, the consequences of such an impact would be apocalyptic. Weissman conservatively estimates the diameter at 35 km; an estimated density of 0.6 g/cm3 then gives a cometary mass of 1.3×1019 g. At a probable impact velocity of 52.5 km/s, impact energy can be calculated as 1.9×1032 ergs, or 4.4×109 megatons, about 44 times the estimated energy of the K-T impact event. Over many orbits, the cumulative effect of gravitational perturbations on comets with high orbital inclinations and small perihelion distances is generally to reduce the perihelion distance to very small values.

A marker that accounts for a substantial global impact of humans on the total environment, comparable in scale to those associated with significant perturbations of the geological past, is needed in place of minor changes in atmosphere composition. A useful candidate for this purpose is the pedosphere, which can retain information of its climatic and geochemical history with features lasting for centuries or millennia. Human activity is now firmly established as the sixth factor of soil formation. It affects pedogenesis directly by, for example, land levelling, trenching and embankment building, organic matter enrichment from additions of manure or other waste, organic matter impoverishment due to continued cultivation and compaction from overgrazing.

Based on apparent changes in the position of Epsilon Eridani between 1938 and 1972, Peter van de Kamp proposed that an unseen companion with an orbital period of 25 years was causing gravitational perturbations in its position. This claim was refuted in 1993 by Wulff-Dieter Heintz and the false detection was blamed on a systematic error in the photographic plates. Launched in 1983, the space telescope IRAS detected infrared emissions from stars near to the Sun, including an excess infrared emission from Epsilon Eridani. The observations indicated a disk of fine-grained cosmic dust was orbiting the star; this debris disk has since been extensively studied.

During the warming in the early Eocene between 52 and 55 million years ago, there were a series of short-term changes of carbon isotope composition in the ocean. These isotope changes occurred due to the release of carbon from the ocean into the atmosphere that led to a temperature increase of at the surface of the ocean. These hyperthermals led to increased perturbations in planktonic and benthic foraminifera, with a higher rate of sedimentation as a consequence of the warmer temperatures. Recent analysis of and research into these hyperthermals in the early Eocene has led to hypotheses that the hyperthermals are based on orbital parameters, in particular eccentricity and obliquity.

Furthermore, the underlying implication would be a unidirectional flow of information from genotype to phenotype. On the other hand, in the scenario resulting from the MRK model wherein learning can guide evolution, changes to the genome arise due to necessity after trial and error and not just by chance, and in a few generations, are fixed. Episodes of rapid change - network rewiring to uncover latent pathway interactions in response to environmental perturbations - could lead to genotypic changes in a relatively short order. In other words, a species need not originate in a series of gradual steps, each resulting from a mutation with a small effect, slowly changing ancestor into descendant.

M2 and M6 The crossing from north to south is the autumnal equinox or descending node. The orientation of Earth's axis and equator are not fixed in space, but rotate about the poles of the ecliptic with a period of about 26,000 years, a process known as lunisolar precession, as it is due mostly to the gravitational effect of the Moon and Sun on Earth's equatorial bulge. Likewise, the ecliptic itself is not fixed. The gravitational perturbations of the other bodies of the Solar System cause a much smaller motion of the plane of Earth's orbit, and hence of the ecliptic, known as planetary precession.

Application of a ramp of negative pressure to a patch excised from an E. coli giant spheroplast gave a small conductance (MscS; ~1 nS in 400 mM salt) with a sustained open state, and a large conductance (MscL; ~3 nS) with faster kinetics, activated at higher pressure. MscS was reported to exhibit a weak anionic preference and a voltage dependency, tending to open upon depolarization. Activation by membrane- intercalating amphipathic compounds suggested that the MscS channel is sensitive to mechanical perturbations in the lipid bilayer. Sensitivity towards tension changes can be explained as result of the hydrophobic coupling between the membrane and TMSs of the channel.

Until his definitive retirement (1995), he devoted himself to rebuilding the Romanian Academy and the geophysical institutions in Romania; he was president of the Romanian National Committee of Geodesy and Geophysics and of the Romanian Society of Geophysics. Liviu Constantinescu has made important contributions to several domains of pure and applied geophysics: geomagnetism (normal distribution and secular variation of the main geomagnetic field, general morphology and particularities of magnetic perturbations, magnetotellurics); handling and interpretation of gravimetric and magnetometric data (analytic continuation of potential fields, effects of Earth tides, time variation of the gravity field); seismology and tectonophysics (focal mechanism of earthquakes, seismicity and seismotectonics, Carpathian earthquakes, seismicity of the Romanian territory).

That Department was less distinguished under Bliss than it had been under E. H. Moore's previous leadership, and than it would become under Marshall Stone's and Saunders MacLane's direction after World War II. A near-contemporary of Bliss's at Chicago was the algebraist Leonard Dickson. During World War I, he worked on ballistics, designing new firing tables for artillery, and lectured on navigation. In 1918, he and Oswald Veblen worked together in the Range Firing Section at the Aberdeen Proving Ground, applying the calculus of variations to correct shell trajectories for the effects of wind, changes in air density, the rotation of the Earth, and other perturbations.

The authors proposed a new scenario in which planet formation starts at the frost line where pebble- size particles trigger streaming instabilities, then protoplanets quickly mature by pebble accretion. When the planets reach Earth mass they create perturbations in the gas disk that halt the inward drift of pebbles causing their growth to stall. The planets are transported by Type I migration to the inner disk, where they stall at the magnetospheric cavity and end up in mean motion resonances. This scenario predicts the planets formed with significant fractions of water, around 10%, with the largest initial fractions of water on the innermost and outermost planets.

A partially corrected solution can be re-used as the new starting point for yet another cycle of perturbations and corrections. In principle, for most problems the recycling and refining of prior solutions to obtain a new generation of better solutions could continue indefinitely, to any desired finite degree of accuracy. The common difficulty with the method is that the corrections usually progressively make the new solutions very much more complicated, so each cycle is much more difficult to manage than the previous cycle of corrections. Newton is reported to have said, regarding the problem of the Moon's orbit "It causeth my head to ache.".

Mathematicians have discovered that it is possible in principle to have multiple bodies in non-elliptical orbits that repeat periodically, although most such orbits are not stable regarding small perturbations in mass, position, or velocity. However, some special stable cases have been identified, including a planar figure-eight orbit occupied by three moving bodies. Further studies have discovered that nonplanar orbits are also possible, including one involving 12 masses moving in 4 roughly circular, interlocking orbits topologically equivalent to the edges of a cuboctahedron. Finding such orbits naturally occurring in the universe is thought to be extremely unlikely, because of the improbability of the required conditions occurring by chance.

In 1851, Krueger entered the University of Berlin where he studied mathematics and science. In 1853, showing a special preference for astronomical studies, Krueger moved to the University of Bonn and became an assistant to the astronomer Friedrich Wilhelm Argelander at the Bonn Observatory. Under Argelander's supervision he produced data for the comprehensive astrometric star catalogue known as the Bonner Durchmusterung, together with fellow student Eduard Schönfeld . Starting in Bonn, he undertook a lifelong study of the orbit of the minor planet Themis, whose perturbations by Jupiter eventually enabled him in 1873 (while at Helsinki Observatory) to determine the mass of the latter planet.

Galilean moons around Jupiter Laplace resonance of Ganymede, Europa, and Io (conjunctions are highlighted by color changes) Ganymede orbits Jupiter at a distance of 1,070,400 km, third among the Galilean satellites, and completes a revolution every seven days and three hours. Like most known moons, Ganymede is tidally locked, with one side always facing toward the planet, hence its day is seven days and three hours. Its orbit is very slightly eccentric and inclined to the Jovian equator, with the eccentricity and inclination changing quasi-periodically due to solar and planetary gravitational perturbations on a timescale of centuries. The ranges of change are 0.0009–0.0022 and 0.05–0.32°, respectively.

Proteus, like the other inner moons of Neptune, is unlikely to be an original body that formed with it, and is more likely to have accreted from the rubble that was produced after Triton's capture. Triton's orbit upon capture would have been highly eccentric, and would have caused chaotic perturbations in the orbits of the original inner Neptunian moons, causing them to collide and reduce to a disc of rubble. Only after Triton's orbit became circularised did some of the rubble disc re-accrete into the present-day moons of Neptune. Proteus initially had a smaller orbit around Neptune, and may have formed closer to the planet.

In theoretical physics, a quasinormal mode is a formal solution of linearized differential equations (such as the linearized equations of general relativity constraining perturbations around a black hole solution) with a complex eigenvalue (frequency). Black holes have many quasinormal modes (also: ringing modes) that describe the exponential decrease of asymmetry of the black hole in time as it evolves towards the perfect spherical shape. Recently, the properties of quasinormal modes have been tested in the context of the AdS/CFT correspondence. Also, the asymptotic behavior of quasinormal modes was proposed to be related to the Immirzi parameter in loop quantum gravity, but convincing arguments have not been found yet.

The expected value is also sometime denoted \langle u\rangle, but it is also seen often with the over-bar notation. Direct Numerical Simulation, or resolving the Navier-Stokes equations completely in (x,y,z,t), is only possible on small computational grids and small time steps when Reynolds numbers are low. Due to computational constraints, simplifications of the Navier-Stokes equations are useful to parameterize turbulence that are smaller than the computational grid, allowing larger computational domains. Reynolds decomposition allows the simplification the Navier–Stokes equations by substituting in the sum of the steady component and perturbations to the velocity profile and taking the mean value.

In the Planet V hypothesis five terrestrial planets were produced during the planetary formation era. The fifth terrestrial planet began on a low-eccentricity orbit between Mars and the asteroid belt with a semi-major axis between 1.8 and 1.9 AU. While long-lived, this orbit was unstable on a time-scale of 600 Myr. Eventually perturbations from the other inner planets drove Planet V onto a high-eccentricity orbit which crossed into the inner asteroid belt. Asteroids were scattered onto Mars-crossing and resonant orbits by close encounters with Planet V. Many of these asteroids then evolved onto Earth-crossing orbits temporarily enhancing the lunar impact rate.

After the completion of all the major mission objectives, the orbit of Chandrayaan-1 spacecraft, which had been at a height of from the lunar surface since November 2008, was raised to . The orbit raising manoeuvres were carried out between 03:30 and 04:30 UTC on 19 May 2009. The spacecraft in this higher altitude enabled further studies on orbit perturbations, gravitational field variation of the Moon and also enabled imaging lunar surface with a wider swath. It was later revealed that the true reason for the orbit change was that it was an attempt to keep the temperature of the probe down.

This difference is caused by local perturbations due to the rapid mass transport. Even though the difference is negligible in some applications, it can still pose a problem in applications that are highly sensitive to variations in volume, such as immunoassays and DNA amplification. To overcome the limitation of the conventional method, an existing droplet can be split by gradually changing the potential of the electrodes at the splitting region instead of simply switching them on and off. Using this method, a noticeable improvement in droplet volume variation, from around 10% variation in volume to less than 1% variation in volume, has been reported.

Developing a robust flow algorithm to calculate the mean flow velocity for the sound path can be quite complicated. Now add to this; sound path reflection from the pipe wall, multipaths to add degrees of freedom, swirl and departure from axisymmetric fully developed flow profile and the problem of integrating the actual velocity flow profile to yield volume flow rate can be an accomplishment. Hence the real performance of ultrasonic meters downstream of perturbations, and the need for calibrations is required.Kamik U., Studzinskl W., Geerligs J., Rogi M., "Performance Evaluation of 8 Inch Mutipath Ultrasonic Meters", A.G.A. operating Section Operations Conference, May, 1997, Nashville TN.

The model of IKAROS at the 61st International Astronautical Congress in 2010 On 21 May 2010, Japan Aerospace Exploration Agency (JAXA) launched the world's first interplanetary solar sail spacecraft "IKAROS" (Interplanetary Kite-craft Accelerated by Radiation Of the Sun) to Venus. Using a new solar- photon propulsion method, it was the first true solar sail spacecraft fully propelled by sunlight,Maiden voyage for first true space sail, New Scientist and was the first spacecraft to succeed in solar sail flight. JAXA successfully tested IKAROS in 2010. The goal was to deploy and control the sail and, for the first time, to determine the minute orbit perturbations caused by light pressure.

Laplace presented a memoir on planetary inequalities in three sections, in 1784, 1785, and 1786. This dealt mainly with the identification and explanation of the perturbations now known as the "great Jupiter–Saturn inequality". Laplace solved a longstanding problem in the study and prediction of the movements of these planets. He showed by general considerations, first, that the mutual action of two planets could never cause large changes in the eccentricities and inclinations of their orbits; but then, even more importantly, that peculiarities arose in the Jupiter–Saturn system because of the near approach to commensurability of the mean motions of Jupiter and Saturn.

In this context commensurability means that the ratio of the two planets' mean motions is very nearly equal to a ratio between a pair of small whole numbers. Two periods of Saturn's orbit around the Sun almost equal five of Jupiter's. The corresponding difference between multiples of the mean motions, , corresponds to a period of nearly 900 years, and it occurs as a small divisor in the integration of a very small perturbing force with this same period. As a result, the integrated perturbations with this period are disproportionately large, about 0.8° degrees of arc in orbital longitude for Saturn and about 0.3° for Jupiter.

Since organisms are constantly exposed to genetic and non-genetic perturbations, robustness is important to ensure the stability of phenotypes. Also, under mutation-selection balance, mutational robustness can allow cryptic genetic variation to accumulate in a population. While phenotypically neutral in a stable environment, these genetic differences can be revealed as trait differences in an environment- dependent manner (see evolutionary capacitance), thereby allowing for the expression of a greater number of heritable phenotypes in populations exposed to a variable environment. Being robust may even be a favoured at the expense of total fitness as an evolutionarily stable strategy (also called survival of the flattest).

Duhem's views on the philosophy of science are explicated in his 1906 work The Aim and Structure of Physical Theory. In this work, he opposed Newton's statement that the Principia's law of universal mutual gravitation was deduced from 'phenomena', including Kepler's second and third laws. Newton's claims in this regard had already been attacked by critical proof-analyses of the German logician Leibniz and then most famously by Immanuel Kant, following Hume's logical critique of induction. But the novelty of Duhem's work was his proposal that Newton's theory of universal mutual gravity flatly contradicted Kepler's Laws of planetary motion because the interplanetary mutual gravitational perturbations caused deviations from Keplerian orbits.

The original comet must certainly have been very large indeed, perhaps as large as 100 km across (for comparison, the nucleus of Comet Hale–Bopp was about 40 km across). Although its orbit is rather different from those of the main two groups, it is possible that the comet of 1680 is also related to the Kreutz sungrazers via a fragmentation many orbits ago. The Kreutz sungrazers are probably not a unique phenomenon. Studies have shown that for comets with high orbital inclinations and perihelion distances of less than about 2 AU, the cumulative effect of gravitational perturbations tends to result in sungrazing orbits.

The addition of a second spatial dimension raises the possibility of showing local perturbations of the spatial geometry by local curvature in the sheet. In the "balloon model" the flat sheet is replaced by a spherical balloon which is inflated from an initial size of zero (representing the big bang). A balloon has positive Gaussian curvature while observations suggest that the real universe is spatially flat, but this inconsistency can be eliminated by making the balloon very large so that it is locally flat to within the limits of observation. This analogy is potentially confusing since it wrongly suggests that the big bang took place at the center of the balloon.

Perturb-seq (also known as CRISP-seq and CROP-seq) refers to a high-throughput method of performing single cell RNA sequencing (scRNA-seq) on pooled genetic perturbation screens. Perturb-seq combines multiplexed CRISPR mediated gene inactivations with single cell RNA sequencing to assess comprehensive gene expression phenotypes for each perturbation. Inferring a gene’s function by applying genetic perturbations to knock down or knock out a gene and studying the resulting phenotype is known as reverse genetics. Perturb-seq is a reverse genetics approach that allows for the investigation of phenotypes at the level of the transcriptome, to elucidate gene functions in many cells, in a massively parallel fashion.

These two properties—weak interactions and thermodynamic stability—can be recalled to rationalise another property often found in self-assembled systems: the sensitivity to perturbations exerted by the external environment. These are small fluctuations that alter thermodynamic variables that might lead to marked changes in the structure and even compromise it, either during or after self-assembly. The weak nature of interactions is responsible for the flexibility of the architecture and allows for rearrangements of the structure in the direction determined by thermodynamics. If fluctuations bring the thermodynamic variables back to the starting condition, the structure is likely to go back to its initial configuration.

The near-time approach uses the recent fossil record (usually from the Late Pleistocene or the Holocene) to provide a long-term context to extant ecosystems dynamics. The fossil record is, in many cases, the only source of information on conditions previous to human impacts. These records can be used as reference baselines for comparisons in order to identify targets for restoration ecology, to analyze species responses to perturbations (natural and anthropogenic), understand historical species distributions and their variability, discriminate the factors that distinguish natural from non- natural changes in biological populations and identify ecological legacies only explicable by referring to past events or conditions.

In analyzing the stability of an aircraft, it is usual to consider perturbations about a nominal steady flight state. So the analysis would be applied, for example, assuming: ::Straight and level flight ::Turn at constant speed ::Approach and landing ::Takeoff The speed, height and trim angle of attack are different for each flight condition, in addition, the aircraft will be configured differently, e.g. at low speed flaps may be deployed and the undercarriage may be down. Except for asymmetric designs (or symmetric designs at significant sideslip), the longitudinal equations of motion (involving pitch and lift forces) may be treated independently of the lateral motion (involving roll and yaw).

The presence of the CνB affects the evolution of CMB anisotropies as well as the growth of matter perturbations in two ways: due to its contribution to the radiation density of the universe (which determines for instance the time of matter- radiation equality), and due to the neutrinos' anisotropic stress which dampens the acoustic oscillations of the spectra. Additionally, free-streaming massive neutrinos suppress the growth of structure on small scales. The WMAP spacecraft's five-year data combined with type Ia supernova data and information about the baryon acoustic oscillation scale yielded Nν = at 68% c.l., providing an independent confirmation of the BBN constraints.

This star system has an apparent visual magnitude of +3.0, making it one of the brighter stars in the constellation and hence readily visible to the naked eye. Parallax measurements from the Hipparcos mission yield a distance estimate of around from the Sun. This is a single-lined spectroscopic binary system, which means that the pair have not been individually resolved with a telescope, but the gravitational perturbations of an unseen astrometric companion can be discerned by shifts in the spectrum of the primary caused by the Doppler effect. The pair orbit around their common center of mass once every 675 days with an eccentricity of 0.57.

We have described what optical solitons are and, using mathematics, we have seen that, if we want to create them, we have to create a field with a particular shape (just sech for the first order) with a particular power related to the duration of the impulse. But what if we are a bit wrong in creating such impulses? Adding small perturbations to the equations and solving them numerically, it is possible to show that mono- dimensional solitons are stable. They are often referred as solitons, meaning that they are limited in one dimension (x or t, as we have seen) and propagate in another one (z).

The peripheral attack model is based on predicting lowest energy conformations of an inherently complicated system, where nuanced perturbations can cause huge stereodifferentiating consequences. By modeling peripheral attack using the Curtin-Hammett scenario depicted above, the transition state is excluded from this conformation analysis by assuming that the barrier to each transition state from a given conformation is the same and thus that ground state conformations are the sole product determining factor. A significant criticism is the mapping of medium-sized ring conformations and influences onto larger ring systems. Macrocycles can possess varying degrees of rigidity in their structure, making a single peripheral attack model difficult to apply to all systems.

Flowchart of sound passage - middle ear The middle ear plays a crucial role in the auditory process, as it essentially converts pressure variations in air to perturbations in the fluids of the inner ear. In other words, it is the mechanical transfer function that allows for efficient transfer of collected sound energy between two different media. The three small bones that are responsible for this complex process are the malleus, the incus, and the stapes, collectively known as the ear ossicles. The impedance matching is done through via lever ratios and the ratio of areas of the tympanic membrane and the footplate of the stapes, creating a transformer-like mechanism.

PtdIns(3,5)P2 regulates endosomal operations (fission and fusion) that maintain endomembrane homeostasis and proper performance of the trafficking pathways emanating from or traversing endosomes. Decrease of PtdIns(3,5)P2 levels upon perturbations of cellular PIKfyve by heterologous expression of enzymatically inactive PIKfyve point mutants, Ikonomov OC, Sbrissa D, Shisheva A. Mammalian cell morphology and endocytic membrane homeostasis require enzymatically active phosphoinositide 5-kinase PIKfyve. J Biol Chem. 2001 Jul 13;276(28):26141-7. Epub 2001 Apr 2. siRNA-medicated silencing, Rutherford AC, Traer C, Wassmer T, Pattni K, Bujny MV, Carlton JG, Stenmark H, Cullen PJ. The mammalian phosphatidylinositol 3-phosphate 5-kinase (PIKfyve) regulates endosome-to-TGN retrograde transport.

Asmeret's research interests center on the effect of changing environmental conditions—specifically fire, erosion, and climate change—on important soil processes. Her group is working to understand how perturbations in the environment affect how essential elements like carbon and nitrogen cycle through the soil system. One of her group's projects is to understand how drought and wildfire affect soil's ability to store carbon, taking her out to Yosemite National Park and the Sierra Nevada for fieldwork. Given the prevalence of drought in California, this work is of particular public importance, and as a result, has been highlighted by public figures like California Congressman Jerry McNerney (D-CA 9th District).

PSR B1257+12 c, alternatively designated PSR B1257+12 B, also named Poltergeist, is an extrasolar planet approximately 2,300 light-years away in the constellation of Virgo. It was one of the first planets ever discovered outside the Solar System, and is one of three pulsar planets known to be orbiting the pulsar PSR B1257+12. Over four times as massive as the Earth, it circles the primary at a distance of 0.36 AU with an orbital period of approximately 66 days. Because it and Phobetor have very similar masses and orbit close to each other, they were expected to cause measurable perturbations in each other's orbits.

Based on this simplification of the problem, Joel Hass and Roger Schlafly were able to reduce the proof of this case of the double bubble conjecture to a large computerized case analysis, taking 20 minutes on a 1995 PC. The eventual proof of the full double bubble conjecture also uses Hutchings' method to reduce the problem to a finite case analysis, but it avoids the use of computer calculations, and instead works by showing that all possible nonstandard double bubbles are unstable: they can be perturbed by arbitrarily small amounts to produce another solution with lower cost. The perturbations needed to prove this result are a carefully chosen set of rotations.

In addition to the Atmospheric and Ocean Department (AOSC), Kalnay has appointments in the Institute for Physical Science and Technology (IPST) and the Center for Computational Science and Mathematical Modeling (CSCAMM), also at the University of Maryland, College Park. In 2008, she was selected as the first Eugenia Brin Endowed Professorship in Data Assimilation. Among the scientific methods Kalnay has pioneered are the breeding method, which was introduced, along with Zoltan Toth, as a method to identify the growing perturbations in a dynamical system. She was also co- author on papers introducing the ensemble methods of Lag Averaged Forecasting (LAF) and Scaled LAF (with Ross N. Hoffman and Wesley Ebisuzaki).

Sachdev argued instead that it is better to examine how rapidly the system loses quantum phase coherence, or reaches local thermal equilibrium in response to general external perturbations. If quasiparticles existed, dephasing would take a long time during which the excited quasiparticles collide with each other. In contrast, states without quasiparticles reach local thermal equilibrium in the fastest possible time, bounded below by a value of order (Planck constant)/((Boltzmann constant) x (absolute temperature)). Sachdev proposed a solvable model of a strange metal (a variant of which is now called the Sachdev-Ye-Kitaev (SYK) model), which was shown to saturate such a bound on the time to reach quantum chaos.

The differences between that and the actual motion of the body are perturbations due to the additional gravitational effects of the remaining body or bodies. If there is only one other significant body then the perturbed motion is a three-body problem; if there are multiple other bodies it is an n-body problem. A general analytical solution (a mathematical expression to predict the positions and motions at any future time) exists for the two-body problem; when more than two bodies are considered analytic solutions exist only for special cases. Even the two-body problem becomes insoluble if one of the bodies is irregular in shape.

Rotational Brownian motion was first discussed in the context of binary supermassive black holes at the centers of galaxies.Merritt, D. (2002), Rotational Brownian Motion of a Massive Binary, The Astrophysical Journal, 568, 998-1003. Perturbations from passing stars can alter the orbital plane of such a binary, which in turn alters the direction of the spin axis of the single black hole that forms when the two coalesce. Rotational Brownian motion is often observed in N-body simulations of galaxies containing binary black holes.Löckmann, U. and Baumgardt, H. (2008), Tracing intermediate-mass black holes in the Galactic Centre, Monthly Notices of the Royal Astronomical Society, 384, 323-330.

In 1859, the French mathematician and astronomer Urbain Le Verrier reported that the slow precession of Mercury's orbit around the Sun could not be completely explained by Newtonian mechanics and perturbations by the known planets. He suggested, among possible explanations, that another planet (or perhaps instead a series of smaller 'corpuscules') might exist in an orbit even closer to the Sun than that of Mercury, to account for this perturbation.Le Verrier, Urbain (1859), (in French), "Lettre de M. Le Verrier à M. Faye sur la théorie de Mercure et sur le mouvement du périhélie de cette planète", Comptes rendus hebdomadaires des séances de l'Académie des sciences (Paris), vol. 49 (1859), pp. 379–383.

A research into the mutual perturbations of Jupiter and Saturn secured for him the prize of the Berlin Academy in 1830, and a memoir on cometary disturbances was crowned by the Paris Academy in 1850. In 1838 he published a revision of the lunar theory, entitled Fundamenta nova investigationis, &c.;, and the improved Tables of the Moon ("Hansen's Lunar Tables")Tables de la lune (Google ebook) based upon it were printed in 1857, at the expense of the British government, their merit being further recognized by a grant of £1000, and by their adoption in the Nautical Almanac as from the issue for the year 1862,Explanatory Supplement to the Astronomical Ephemeris, (London, 1961), sect. 7B, p. 178.

Research on twins suggests that there are genetic influences on FA, and increased levels of mutations and perturbations is also linked to greater asymmetry. FA may also result from a lack of genetic immunity to diseases, as those with higher FA show less effective immune responses. This is further supported by evidence showing an association between FA and the number of respiratory infections experienced by an individual, such that those with higher levels of FA experience more infections. Increased prevalence of parasites and diseases in an organism is also seen more in individuals with greater levels of FA. However, the research in this field is predominantly correlational, so caution must be taken when inferring causation.

They cite the example of the Mount Tambora volcanic eruption in 1815, which produced an average annual temperature deviation of only −0.7 °C, but which brought mid- summer killing frosts to the mid-Atlantic states and caused up to 75% crop losses in northern Europe. In addition, the report authors argue that small perturbations in the food supply are highly amplified for malnourished populations. In particular, about 800 million people are chronically malnourished, and even a 10% decline in their food consumption would put them at risk. World reserves of grain stocks could serve as a buffer to this; however, rough estimates suggest that current reserves would only last approximately 68–77 days.

If sufficiently strong nonlinear terms are present in the energy function, energy may be transferred between the normal modes, leading to ergodicity and rendering the law of equipartition valid. However, the Kolmogorov–Arnold–Moser theorem states that energy will not be exchanged unless the nonlinear perturbations are strong enough; if they are too small, the energy will remain trapped in at least some of the modes. Another way ergodicity can be broken is by the existence of nonlinear soliton symmetries. In 1953, Fermi, Pasta, Ulam and Tsingou conducted computer simulations of a vibrating string that included a non-linear term (quadratic in one test, cubic in another, and a piecewise linear approximation to a cubic in a third).

This competition between forces (pressure and gravity) enabled the photon-baryon plasma to support pressure waves which were sourced by the initial perturbations in the density field. When recombination occurred at roughly 380,000 years after the big bang, the photons and baryons decoupled from one another and the plasma lost its ability to support sound waves. One consequence of this decoupling was that the oscillations in the photon-baryon plasma were imprinted on the photon fluid; these are the oscillations that we observe in the Cosmic Microwave Background (CMB) angular power spectrum. Another consequence of the decoupling was that the baryons lost their pressure support and began to collapse into gravitational potential wells.

The Crab Nebula was first identified in 1731 by John Bevis. The nebula was independently rediscovered in 1758 by Charles Messier as he was observing a bright comet. Messier catalogued it as the first entry in his catalogue of comet-like objects; in 1757, Alexis Clairaut reexamined the calculations of Edmund Halley and predicted the return of Halley's Comet in late 1758. The exact time of the comet's return required the consideration of perturbations to its orbit caused by planets in the Solar System such as Jupiter, which Clairaut and his two colleagues Jérôme Lalande and Nicole-Reine Lepaute carried out more precisely than Halley, finding that the comet should appear in the constellation of Taurus.

169, 738–747van Nes, E., and Scheffer, M. (2005) Implications of spatial heterogeneity for catastrophic regime shifts in ecosystems. Ecology 86, 1797–1807Hastings, A., and Wysham, D.B. (2010) Regime shifts in ecological systems can occur with no warning. Ecol Lett, 1–9 Systems approaching a bifurcation point show a characteristic behaviour called critical slowing down leading to an increasingly slow recovery from perturbations. This, in turn, may lead to an increase in (spatial or temporal) autocorrelation and variance, while variance spectra tend to lower frequencies, and the 'direction of critical slowing down' in a system's state space may be indicative of a system's future state when delayed negative feedbacks leading to oscillatory or other complex dynamics are weak.

U. Le Verrier (1859), (in French), "Lettre de M. Le Verrier à M. Faye sur la théorie de Mercure et sur le mouvement du périhélie de cette planète", Comptes rendus hebdomadaires des séances de l'Académie des sciences (Paris), vol. 49 (1859), pp. 379–383. (At p. 383 in the same volume Le Verrier's report is followed by another, from Faye, enthusiastically recommending to astronomers to search for a previously undetected intra- mercurial object.) (Other explanations considered included a slight oblateness of the Sun.) The success of the search for Neptune based on its perturbations of the orbit of Uranus led astronomers to place some faith in this possible explanation, and the hypothetical planet was even named Vulcan.

The object's discovery was reported to the Minor Planet Center's Near-Earth Object Confirmation Page (NEOCP), where a preliminary orbit was calculated from additional observations conducted at several observatories. Follow-up observations of spanned six days since its discovery, and the object was formally announced in a Minor Planet Electronic Circular notice issued by the Minor Planet Center on 25 February 2020. No indication of perturbations by solar radiation pressure was observed, and could not be linked to any known artificial object. Although the evidence implied that is most likely a dense, rocky asteroid, the possibility of the object being an artificial object, such as a dead satellite or rocket booster, had not yet been fully ruled out.

A least-squares technique was used to perform the fitting. As of DE421, perturbations from 343 asteroids, representing about 90% of the mass of the main asteroid belt, have been included in the dynamical model. The physics modeled included the mutual Newtonian gravitational accelerations and their relativistic corrections (a modified form of the Einstein-Infeld-Hoffmann equation), the accelerations caused by the tidal distortion of the Earth, the accelerations caused by the figure of the Earth and Moon, and a model of the lunar librations. The observational data in the fits has been an evolving set, including: ranges (distances) to planets measured by radio signals from spacecraft,See for a good summary of spacecraft radio-navigation.

M37 has at least a dozen red giants and its hottest surviving main sequence star is of stellar classification B9 V. The abundance of elements other than hydrogen and helium, what astronomers term metallicity, is similar to, if not slightly higher than, the abundance in the Sun. At its estimated distance of around from Earth, the cluster's angular diameter of 24 arcminutes corresponds to a physical extent of about . The tidal radius of the cluster, where external gravitational perturbations begin to have a significant influence on the orbits of its member stars, is about . This cluster is following an orbit through the Milky Way with a period of 219.3 Ma and an eccentricity of 0.22.

The Gregory–Laflamme instability (after Ruth Gregory and Raymond Laflamme) is a result in theoretical physics which states that certain black strings and branes are unstable in dimensions higher than four. In their seminal papers in 1993 and 1994, Gregory and Laflamme showed that certain branes and Higher- dimensional Einstein gravity black string solutions in theories of gravity in higher dimensions D \ge 5 are found to exhibit an instability to small perturbations. the end point of this instability has been studied to higher dimensions and a critical dimension has been found to exist below which the end state of instability is a black hole phase, i.e., for 5 \le D \le 13.

Animation of 4179 Toutatis's orbit around Sun With a semimajor axis of 2.5294 AU, or roughly 2.5 times the distance between Earth and the Sun, Toutatis has a 3:1 orbital resonance with Jupiter and a near-1:4 resonance with Earth. It thus completes one orbit around the Sun for every 4.02 annual orbits of Earth. The gravitational perturbations caused by frequent close approaches to the terrestrial planets lead to chaotic behavior in the orbit of Toutatis, making precise long-term predictions of its location progressively inaccurate over time. Estimates in 1993 put the Lyapunov time horizon for predictability at around 50 years, after which the uncertainty region becomes larger with each close approach to a planet.

Intermediate stage of a jet breaking into drops. Radii of curvature in the axial direction are shown. Equation for the radius of the stream is R(z) = R_0 + A_k \cos(kz), where R_0 is the radius of the unperturbed stream, A_k is the amplitude of the perturbation, \scriptstyle z is distance along the axis of the stream, and k is the wave number The explanation of this instability begins with the existence of tiny perturbations in the stream. These are always present, no matter how smooth the stream is (for example, in the liquid jet nozzle, there is vibration on the liquid stream due to a friction between the nozzle and the liquid stream).

On March 14, 2012, the entire catalog of the WISE mission was released. In 2014 WISE data ruled out a Saturn or larger- sized body in the Oort cloud out to ten thousand AU.NASA's WISE Survey Finds Thousands of New Stars, But No 'Planet X' Calculations in the 1980s suggested that a Nemesis object would have an irregular orbit due to perturbations from the galaxy and passing stars. The Melott and Bambach work shows an extremely regular signal, inconsistent with the expected irregularities in such an orbit. Thus, while supporting the extinction periodicity, it appears to be inconsistent with the Nemesis hypothesis, though of course not inconsistent with other kinds of substellar objects.

This structure is thought to arise, in several different ways, from the gravitational pull of Saturn's many moons. Some gaps are cleared out by the passage of tiny moonlets such as Pan, many more of which may yet be discovered, and some ringlets seem to be maintained by the gravitational effects of small shepherd satellites (similar to Prometheus and Pandora's maintenance of the F ring). Other gaps arise from resonances between the orbital period of particles in the gap and that of a more massive moon further out; Mimas maintains the Cassini Division in this manner. Still more structure in the rings consists of spiral waves raised by the inner moons' periodic gravitational perturbations at less disruptive resonances.

Given any two smooth submanifolds, it is possible to perturb either of them by an arbitrarily small amount such that the resulting submanifold intersects transversally with the fixed submanifold. Such perturbations do not affect the homology class of the manifolds or of their intersections. For example, if manifolds of complementary dimension intersect transversally, the signed sum of the number of their intersection points does not change even if we isotope the manifolds to another transverse intersection. (The intersection points can be counted modulo 2, ignoring the signs, to obtain a coarser invariant.) This descends to a bilinear intersection product on homology classes of any dimension, which is Poincaré dual to the cup product on cohomology.

Some argue that strong linkages between countries are not necessarily financial contagion, and that financial contagion should be defined as an increase in cross-market linkages after a shock to one country, which is very hard to figure out by both theoretical model and empirical work. Also, some scholars argue that there is actually no contagion at all, just a high level of market co-movement in all periods, which is market "interdependence". More generally, there is controversy surrounding the usefulness of "contagion" as a metaphor to describe the "catchiness" of social phenomena, as well as debate about the application of context-specific models and concepts from biomedicine and epidemiology to explain the diffusion of perturbations within financial systems.

Whether or not a system of star, planet, and trojan is stable depends on how large the perturbations are to which it is subject. If, for example, the planet is the mass of Earth, and there is also a Jupiter-mass object orbiting that star, the trojan's orbit would be much less stable than if the second planet had the mass of Pluto. As a rule of thumb, the system is likely to be long-lived if m1 > 100m2 > 10,000m3 (in which m1, m2, and m3 are the masses of the star, planet, and trojan). More formally, in a three-body system with circular orbits, the stability condition is 27(m1m2 \+ m2m3 \+ m3m1) < (m1 \+ m2 \+ m3)2.

In real semiconductor heterojunctions, Anderson's rule fails to predict actual band offsets. In Anderson's idealized model the materials are assumed to behave as they would in the limit of a large vacuum separation, yet where the vacuum separation is taken to zero. It is that assumption that involves the use of the vacuum electron affinity parameter, even in a solidly filled junction where there is no vacuum. Much like with the Schottky–Mott rule, Anderson's rule ignores the real chemical bonding effects that occur with a small or nonexistent vacuum separation: interface states which may have a very large electrical polarization and defect states, dislocations and other perturbations caused by imperfect crystal lattice matches.

Biological systems exist as a complex interplay of countless cellular components interacting across four dimensions to produce the phenomenon called life. While it is common to reduce living organisms to non-living samples to accommodate traditional static imaging tools, the further the sample deviates from the native conditions the more likely the delicate processes in question will exhibit perturbations. The onerous task of capturing the true physiological identity of living tissue, therefore, requires high-resolution visualization across both space and time within the parent organism. The technological advances of live-cell imaging, designed to provide spatiotemporal images of subcellular events in real-time, serves an important role for corroborating the biological relevance of physiological changes observed during experimentation.

As with any highly complex system, however, even small perturbations to its environment can lead to significant functional disruptions. Properties leading to the susceptibility of nervous tissue include a high surface area of neurons, a high lipid content which retains lipophilic toxins, high blood flow to the brain inducing increased effective toxin exposure, and the persistence of neurons through an individual's lifetime, leading to compounding of damages.Dobbs 2009 As a result, the nervous system has a number of mechanisms designed to protect it from internal and external assaults, including the blood brain barrier. The blood-brain barrier (BBB) is one critical example of protection which prevents toxins and other adverse compounds from reaching the brain.

Screening of negatively charged particle in a pool of positive ions Friedel oscillations , named after French physicist Jacques Friedel, arise from localized perturbations in a metallic or semiconductor system caused by a defect in the Fermi gas or Fermi liquid. Friedel oscillations are a quantum mechanical analog to electric charge screening of charged species in a pool of ions. Whereas electrical charge screening utilizes a point entity treatment to describe the make-up of the ion pool, Friedel oscillations describing fermions in a Fermi fluid or Fermi gas require a quasi-particle or a scattering treatment. Such oscillations depict a characteristic exponential decay in the fermionic density near the perturbation followed by an ongoing sinusoidal decay resembling sinc function.

This theory combines the benefits of matter bounce and Ekpyrotic cosmology. Particularly, the famous BKL instability, that the homogeneous and isotropic background cosmological solution is unstable to the growth of anisotropic stress, is resolved in this theory. Moreover, curvature perturbations seeded in matter contraction are able to form a nearly scale-invariant primordial power spectrum and thus provides a consistent mechanism to explain the cosmic microwave background (CMB) observations. A few sources argue that distant supermassive black holes whose large size is hard to explain so soon after the Big Bang, such as ULAS J1342+0928, may be evidence for a Big Bounce, with these supermassive black holes being formed before the Big Bounce.

We can imagine "disturbing" the gravitational field outside some isolated massive object by "sending in some radiation from infinity". We can ask: what happens as the incoming radiation interacts with the ambient field? In the approach of classical perturbation theory, we can start with Minkowski vacuum (or another very simple solution, such as the de Sitter lambdavacuum), introduce very small metric perturbations, and retain only terms up to some order in a suitable perturbation expansion—somewhat like evaluating a kind of Taylor series for the geometry of our spacetime. This approach is essentially the idea behind the post-Newtonian approximations used in constructing models of a gravitating system such as a binary pulsar.

The modern theory of frozen orbits is based on the algorithm given in a 1989 article by Mats Rosengren. For this the analytical expression () is used to iteratively update the initial (mean) eccentricity vector to obtain that the (mean) eccentricity vector several orbits later computed by the precise numerical propagation takes precisely the same value. In this way the secular perturbation of the eccentricity vector caused by the J_2\, term is used to counteract all secular perturbations, not only those (dominating) caused by the J_3\, term. One such additional secular perturbation that in this way can be compensated for is the one caused by the solar radiation pressure, this perturbation is discussed in the article "Orbital perturbation analysis (spacecraft)".

Eicosanoid biosynthesis begins when a cell is activated by mechanical trauma, ischemia, other physical perturbations, attack by pathogens, or stimuli made by nearby cells, tissues, or pathogens such as chemotactic factors, cytokines, growth factors, and even certain eicosanoids. The activated cells then mobilize enzymes, termed phospholipase A2's (PLA2s), capable of releasing ω-6 and ω-3 fatty acids from membrane storage. These fatty acids are bound in ester linkage to the SN2 position of membrane phospholipids; PLA2s act as esterases to release the fatty acid. There are several classes of PLA2s with type IV cytosolic PLA2s (cPLA2s) appearing to be responsible for releasing the fatty acids under many conditions of cell activation.

In fact, its orbit had changed. Tempel 1's orbit occasionally brings it sufficiently close to Jupiter to be altered, with a consequent change in the comet's orbital period. This occurred in 1881 (closest approach to Jupiter of 0.55 AU), lengthening the orbital period to 6.5 years. Perihelion also changed, increasing by 50 million kilometres, rendering the comet far less visible from Earth. Detail of crater-like features on Comet Tempel 1 in image taken by Deep Impacts impactor Tempel 1 was rediscovered 13 orbits later in 1967 (as 9P/1967 L1, 1966 VII), after British astronomer Brian G. Marsden performed precise calculations of the comet's orbit that took into account Jupiter's perturbations.

Shearography output image of CFRP/honeycomb part with artificial defectsLaser Shearography involves accurately measuring perturbations in the surfaces of a (usually thin) part under load or strain with the aid of lasers scanning across the surface being evaluated. Voids, pores, delaminations and other defects in composite welds can be detected by this method. Acoustic Emission testing provides qualitative information on the presence and potential growth of defects such as cracks and delaminations in welded composite materials. Typically this method is used to help narrow down the locations(s) of defects in large structures before using a more precise NDT method such as radiography or ultrasonic testing to help localize and characterize the nature of the defect.

Basic operation for a single axis An active magnetic bearing (AMB) works on the principle of electromagnetic suspension and consists of an electromagnet assembly, a set of power amplifiers which supply current to the electromagnets, a controller, and gap sensors with associated electronics to provide the feedback required to control the position of the rotor within the gap. These elements are shown in the diagram. The power amplifiers supply equal bias current to two pairs of electromagnets on opposite sides of a rotor. This constant tug-of-war is mediated by the controller which offsets the bias current by equal but opposite perturbations of current as the rotor deviates by a small amount from its center position.

Originally, it was thought that ecosystems increase uniformly in ascendency as they developed, but subsequent empirical observation has suggested that all sustainable ecosystems are confined to a narrow "window of vitality" (Ulanowicz 2002). Systems with relative values of ascendency plotting below the window tend to fall apart due to lack of significant internal constraints, whereas systems above the window tend to be so "brittle" that they become vulnerable to external perturbations. Sensitivity analysis on the components of the ascendency reveals the controlling transfers within the system in the sense of Liebig (Ulanowicz and Baird 1999). That is, ascendency can be used to identify which resource is limiting the functioning of each component of the ecosystem.

The Tusculanae Disputationes consist of five books: # "On the contempt of death" # "On bearing pain" # "On grief of mind" # "On other perturbations of the mind" # "Whether virtue alone be sufficient for a happy life" The purpose of Cicero's lectures is to fortify the mind with practical and philosophical lessons adapted to the circumstances of life, to elevate us above the influence of all its passions and pains. In each of the dialogues, one of the guests, who is called the Auditor, sets up a topic for discussion. Each dialogue begins with an introduction on the excellence of philosophy, and the advantage of adopting the wisdom of the Greeks into the Latin language.

Daisyworld simulations where environmental changes were stable gradually became less diverse over time; in contrast gentle perturbations led to bursts of species richness. These findings lent support to the idea that biodiversity is valuable. This finding was supported by an eleven-year-old study of the factors species composition, dynamics and diversity in successional and native grasslands in Minnesota by David Tilman and John A. Downing wherein they discovered that "primary productivity in more diverse plant communities is more resistant to, and recovers more fully from, a major drought". They go on to add "Our results support the diversity stability hypothesis but not the alternative hypothesis that most species are functionally redundant".

The SPRES algorithm branches simulation paths at fixed time intervals. The process of branching requires that identical paths can be made to diverge from each other, such as by changing the seed in the computer's random number generator. For systems which would be naturally considered as deterministic, it may be possible to inject an element of randomness, for instance by coupling to a fluctuating heat bath or by adding random perturbations to account for some elements of the simulation which are not modelled explicitly but which exist in the real system. The amount of over or under-sampling (the branching density) is decided based on some system- specific 'progress coordinate' which measures progress toward a rare event of interest.

The formation of dark matter halos is believed to have played a major role in the early formation of galaxies. During initial galactic formation, the temperature of the baryonic matter should have still been much too high for it to form gravitationally self-bound objects, thus requiring the prior formation of dark matter structure to add additional gravitational interactions. The current hypothesis for this is based on cold dark matter (CDM) and its formation into structure early in the universe. The hypothesis for CDM structure formation begins with density perturbations in the Universe that grow linearly until they reach a critical density, after which they would stop expanding and collapse to form gravitationally bound dark matter halos.

The developers performed studies showing that MYCIN's performance was minimally affected by perturbations in the uncertainty metrics associated with individual rules, suggesting that the power in the system was related more to its knowledge representation and reasoning scheme than to the details of its numerical uncertainty model. Some observers felt that it should have been possible to use classical Bayesian statistics. MYCIN's developers argued that this would require either unrealistic assumptions of probabilistic independence, or require the experts to provide estimates for an unfeasibly large number of conditional probabilities. Subsequent studies later showed that the certainty factor model could indeed be interpreted in a probabilistic sense, and highlighted problems with the implied assumptions of such a model.

The deep-time approach uses examples of species, communities and ecosystem responses to environmental changes on a longer geologic record, as an archive of natural ecological and evolutionary laboratory. This approach provides examples to infer possible settings concerning climate warming, introduction of invasive species and decline in cultural eutrophication. This also permits the identification of species responses to perturbations of various types and scale to serve as a model for the future scenarios, for example abrupt climate change or volcanic winters. Given its deep-time nature, this approach allows for testing how organisms or ecosystems react to a bigger set of conditions than what is observable in the modern world or in the recent past.

Although the ability of ice to reject suspended particles in the growth process has long been known, the mechanism remains the subject of some discussion. It was believed initially that during the moments immediately following the nucleation of the ice crystals, particles are rejected from the growing planar ice front, leading to the formation of a constitutionally super-cooled zone directly ahead of the growing ice. This unstable region eventually results in perturbations, breaking the planar front into a columnar ice front, a phenomenon better known as a Mullins-Serkerka instability. After the breakdown, the ice crystals grow along the temperature gradient, pushing ceramic particles from the liquid phase aside so that they accumulate between the growing ice crystals.

Simulations of the formation of the terrestrial planets using models of the protoplanetary disk that include viscous heating and the migration of the planetary embryos indicate that Jupiter's migration may have reversed at 2.0 AU. In simulations the eccentricities of the embryos are excited by perturbations from Jupiter. As these eccentricities are damped by the denser gas disk of recent models, the semi-major axes of the embryos shrink, shifting the peak density of solids inward. For simulations with Jupiter's migration reversing at 1.5 AU, this resulted in the largest terrestrial planet forming near Venus's orbit rather than at Earth's orbit. Simulations that instead reversed Jupiter's migration at 2.0 AU yielded a closer match to the current Solar System.

The apsides of planet c and d, instead, oscillates with time; the orbit of Upsilon Andromedae c thus returns to a nearly circular state every 9,000 years. The eccentricity of those planets may have arisen from a close encounter between the outer planet and a fourth planet, with the result that the third planet was ejected from the system or destroyed. Such a mechanism could have been triggered by perturbations on the orbit of the companion star, which arise from close encounters with other stars and from the tidal field of the Milky Way. The orbits of the two inner planets seems to be shaped by tidal interactions, while the evolution of c and d orbits is secular.

The leading area of a squall line is composed primarily of multiple updrafts, or singular regions of an updraft, rising from ground level to the highest extensions of the troposphere, condensing water and building a dark, ominous cloud to one with a noticeable overshooting top and anvil (thanks to synoptic scale winds). Because of the chaotic nature of updrafts and downdrafts, pressure perturbations are important. As thunderstorms fill into a distinct line, strong leading-edge updrafts – occasionally visible to a ground observer in the form of a shelf cloud – may appear as an ominous sign of potential severe weather. Beyond the strong winds because of updraft/downdraft behavior, heavy rain (and hail) is another sign of a squall line.

This transferred the uncertainty from the gravitational constant to an uncertainty in the semi-major axis of the Earth-Sun system, which was no longer exactly one au (the au being defined as depending on the value of the gravitational constant). The astronomical unit thus became a measured quantity rather than a defined, fixed one. In 1976, the IAU reconfirmed the Gaussian constant's status at the XVIth General Assembly in Grenoble, declaring it to be a defining constant, and that From this definition, the mean distance of Earth from the Sun works out to , but with perturbations by the other planets, which do not average to zero over time, the average distance is .

In 2001, Billard proposed a biologically plausible model of human imitation and discussed its applicability in robot teaching. The model was able to learn the principal features of an arm trajectory in a throwing/catching imitation task, was able to generalize across different demonstrations, was able to learn on- line, and its movements were robust to perturbations. Billard continued to explore more biologically inspired connectionist architectures with which to train robots to learn complex arm movements by imitation. She based her artificial neural networks on brain regions such as the visual and motor cortices and incorporated a decision making occurs region as well. This allowed Billard’s model to imitate a teacher just as well as a human subject would imitate in the same task.

Magnetization (J) or flux density (B) curve as a function of magnetic field intensity (H) in ferromagnetic material. The inset shows Barkhausen jumps. Research into the study of small perturbations within a large domains began in the late 1910s when Heinrich Barkhausen investigated how the domains, or dipoles, within a ferromagnetic material changed under the influence of an external magnetic field. When demagnetised, a magnet’s dipoles are pointing in random directions hence the net magnetic force from all the dipoles will be zero. By coiling an iron bar with wire and passing an electrical current through the wire, a magnetic field perpendicular to the coil is produced (Fleming’s right hand rule for a coil), this causes the dipoles within the magnet to align to the external field.

By simulating earthquakes it is possible to observe the Gutenberg–Richter law, in this system the random component would have represented random perturbations in the ground and air and this could be anything from a violent weather system, natural continuous stimuli like a river flowing, waves hitting the shoreline or human activity such as drilling. This is much like the butterfly effect where one could not predict a future outcome of an event nor trace back to the original condition from a set time during the simulation and at the macroscopic level appears insignificant, but at the microscopic level may have been the cause for a chain reaction of events; one cell switching on may be responsible for the whole system flipping on.

Around the same time in 1845 he sent a copy of his thesis to Urbain Le Verrier, but only received an answer a year later. Sent on 18 September 1846, it reached Galle on the morning of 23 September. Le Verrier had been investigating the perturbations of the orbit of the planet Uranus and from this he derived the position of a still undiscovered planet, and requested Galle to search in the corresponding section of sky. The very same night (after Encke gave permission to search, against his own judgement), in collaboration with his assistant Heinrich Louis d'Arrest, Galle discovered a star of 8th magnitude, only 1° away from the calculated position, which was not recorded in the Berliner Akademischen Sternkarte.

Subsequently, Muller branched out into other areas of science, and in particular the Earth sciences. His work has included attempting to understand the ice ages, dynamics at the core-mantle boundary, patterns of extinction and biodiversity through time, and the processes associated with impact cratering. One of his most well known proposals is the Nemesis hypothesis suggesting the Sun could have an as yet undetected companion dwarf star, whose perturbations of the Oort cloud and subsequent effects on the flux of comets entering the inner Solar System could explain an apparent 26 million year periodicity in extinction events. In March 2011, he testified to the U.S. House Science, Space and Technology Committee that preliminary data confirmed an overall global warming trend.

He is perhaps most famous for his theory that the planetary rings of Saturn were formed when a large icy moon came too close to Saturn and was pulled apart by gravitational forces. He described a method of calculating the distance at which an object held together only by gravity would break up due to tidal forces; this distance became known as the Roche limit. His other best known works also involved orbital mechanics. The Roche sphere describes the limits at which an object which is in orbit around two other objects will be captured by one or the other, and the Roche lobe approximates the gravitational sphere of influence of one astronomical body in the face of perturbations from another heavier body around which it orbits.

Some deep learning architectures display problematic behaviors, such as confidently classifying unrecognizable images as belonging to a familiar category of ordinary images and misclassifying minuscule perturbations of correctly classified images. Goertzel hypothesized that these behaviors are due to limitations in their internal representations and that these limitations would inhibit integration into heterogeneous multi-component artificial general intelligence (AGI) architectures. These issues may possibly be addressed by deep learning architectures that internally form states homologous to image-grammar decompositions of observed entities and events. Learning a grammar (visual or linguistic) from training data would be equivalent to restricting the system to commonsense reasoning that operates on concepts in terms of grammatical production rules and is a basic goal of both human language acquisitionMiller, G. A., and N. Chomsky.

The sednoids' orbits cannot be explained by perturbations from the giant planets, nor by interaction with the galactic tides. If they formed in their current locations, their orbits must originally have been circular; otherwise accretion (the coalescence of smaller bodies into larger ones) would not have been possible because the large relative velocities between planetesimals would have been too disruptive. Their present elliptical orbits can be explained by several hypotheses: # These objects could have had their orbits and perihelion distances "lifted" by the passage of a nearby star when the Sun was still embedded in its birth star cluster. # Their orbits could have been disrupted by an as-yet-unknown planet-sized body beyond the Kuiper belt such as the hypothesized Planet Nine.

Each of the proposed mechanisms for Sedna's extreme orbit would leave a distinct mark on the structure and dynamics of any wider population. If a trans-Neptunian planet were responsible, all such objects would share roughly the same perihelion (≈80 AU). If Sedna had been captured from another planetary system that rotated in the same direction as the Solar System, then all of its population would have orbits on relatively low inclinations and have semi- major axes ranging from 100–500 AU. If it rotated in the opposite direction, then two populations would form, one with low and one with high inclinations. The perturbations from passing stars would produce a wide variety of perihelia and inclinations, each dependent on the number and angle of such encounters.

Bellen has made numerous important contributions in the field of synaptic transmission in Drosophila. Through unbiased forward genetic screens designed to detect perturbations in neuronal function, he has uncovered many genes involved in synaptic transmission and has used reverse genetics to help to establish their function. His lab was the first to provide in vivo evidence that Synaptotagmin 1 functions as the main Calcium sensor in synaptic transmission and that Syntaxin-1A plays a critical role in synaptic vesicle (SV) fusion in vivo. His lab showed that Endophilin and Synaptojanin control uncoating of SVs, that the V0 component of the v-ATPase affects SV fusion, that synaptic mitochondria control SV dynamics, and in addition discovered a novel calcium channel involved in SV biogenesis.

A popular modularity maximization approach is the Louvain method, which iteratively optimizes local communities until global modularity can no longer be improved given perturbations to the current community state. An algorithm that utilizes the RenEEL scheme, which is an example of the Extremal Ensemble Learning (EEL) paradigm, is currently the best modularity maximizing algorithm. The usefulness of modularity optimization is questionable, as it has been shown that modularity optimization often fails to detect clusters smaller than some scale, depending on the size of the network (resolution limit ); on the other hand the landscape of modularity values is characterized by a huge degeneracy of partitions with high modularity, close to the absolute maximum, which may be very different from each other.

Their evidence suggests that the increasing temperature stress and the declining ocean saturation state of aragonite is making it difficult for reef corals to deposit calcium carbonate. explored how multiple stressors, such as increased nutrient loads and fishing pressure, move corals into less desirable ecosystem states. showed that ocean acidification will significantly change the distribution and abundance of a whole range of marine life, particularly species "that build skeletons, shells, and tests of biogenic calcium carbonate. "Increasing temperatures, surface UV radiation levels and ocean acidity all stress marine biota, and the combination of these stresses may well cause perturbations in the abundance and diversity of marine biological systems that go well beyond the effects of a single stressor acting alone.

As noted above MetPA performs two types of pathway analysis: 1) Pathway (or Metabolite Set) Enrichment Analysis; and 2) Pathway Topological Analysis. Pathway Enrichment Analysis (which is similar to MSEA) identifies which metabolic pathways have compounds (from the input lists) that are over-represented and have significant perturbations to their concentrations. MetPA uses a number of robust statistical measures to identify which pathways and which metabolites are over-represented. Pathway Topological Analysis measures the centrality of a metabolite in a metabolic network or a metabolic pathway. Central or highly important metabolites are “hubs”, located in the center of a metabolic pathway or process. MetPA employs a number of topological assessment tools to measure centrality or “hubness” in an objective manner (called Pathway Impact).

Each of the proposed mechanisms for Sedna's extreme orbit would leave a distinct mark on the structure and dynamics of any wider population. If a trans-Neptunian planet was responsible, all such objects would share roughly the same perihelion (about 80 AU). If Sedna were captured from another planetary system that rotated in the same direction as the Solar System, then all of its population would have orbits on relatively low inclinations and have semi-major axes ranging from 100 to 500 AU. If it rotated in the opposite direction, then two populations would form, one with low and one with high inclinations. The perturbations from passing stars would produce a wide variety of perihelia and inclinations, each dependent on the number and angle of such encounters.

For terrestrial gravimetric measurements this is a near-impossibility, in spite of close international co-operation within the International Association of Geodesy (IAG), e.g., through the International Gravity Bureau (BGI, Bureau Gravimétrique International). Another approach is to combine multiple information sources: not just terrestrial gravimetry, but also satellite geodetic data on the figure of the Earth, from analysis of satellite orbital perturbations, and lately from satellite gravity missions such as GOCE and GRACE. In such combination solutions, the low-resolution part of the geoid solution is provided by the satellite data, while a 'tuned' version of the above Stokes equation is used to calculate the high-resolution part, from terrestrial gravimetric data from a neighbourhood of the evaluation point only.

A primer on quantum mechanics (such as from David J. Griffiths' "Introduction to Quantum Mechanics") suggests that the very notion of having a molecule choose a state over all others purely based on an exterior system, with no simultaneous effects on said molecule, is completely contrary to how quantum mechanics works. Quantum mechanical states are dependent on things like energy and other physical phenomena. Furthermore, imposing a viewpoint that one outcome is best implies that a best configuration needs some formal definition that is independent of mentioning organism lifespan, reproductivity, etc. (as quantum mechanics does not depend on those things) and that the best configuration does depend on things such as energy levels, perturbations to the molecule, and similar things.

The Trans- Species Modeling Theory (TSMT) was written by Ray Greek MD, the president of Americans for Medical Advancement. It states, “while trans-species exploration is possible when perturbations concern lower levels of organization or when studying morphology and function on the gross level, one evolved, complex system will not be of predictive value for another when the perturbation affects higher levels of organization.” In other words, when studying higher level organisms, the predictive value to drugs is not accurate because there are too many differences between their complexities. These differences mean that there are different responses to treatments. Higher level organisms are so complex that there is a variation in responses, even within organisms of the same species, depending on each individual organism’s initial state.

There has been some disagreement over the exact differences between 'metabolomics' and 'metabonomics'. The difference between the two terms is not related to choice of analytical platform: although metabonomics is more associated with NMR spectroscopy and metabolomics with mass spectrometry-based techniques, this is simply because of usages amongst different groups that have popularized the different terms. While there is still no absolute agreement, there is a growing consensus that 'metabolomics' places a greater emphasis on metabolic profiling at a cellular or organ level and is primarily concerned with normal endogenous metabolism. 'Metabonomics' extends metabolic profiling to include information about perturbations of metabolism caused by environmental factors (including diet and toxins), disease processes, and the involvement of extragenomic influences, such as gut microflora.

The optomotor response is essential for animals to correct unplanned course perturbations while navigating through their environment, such as current shifts around a swimming fish or air gusts around flying insects. The response is rapid and instinctual, with pure delay times of just 20-40ms for fruit flies in flight. The optomotor response is a central feature of a fly's flight control system: flies subject to unplanned apparent self-motion move to minimize the resultant optic flow (retinal movement patterns) and correct involuntary deviations from course. In their natural environments, full-field optic flow patterns are elicited by distinct flight maneuvers; for instance, rotational optic flow is generated by body rotation during hovering, whereas expansion optic flow is elicited by body translation during straight flight.

Molecular Spectra and Molecular Structure IV. Constants of Diatomic Molecules, by K. P. Huber and Gerhard Herzberg (Van nostrand Reinhold company, New York, 1979, ), is a classic comprehensive multidisciplinary reference text contains a critical compilation of available data for all diatomic molecules and ions known at the time of publication - over 900 diatomic species in all - including electronic energies, vibrational and rotational constants, and observed transitions. Extensive footnotes discuss the reliability of these data and additional detailed informationon potential energy curves, spin- coupling constants, /\\-type doubling, perturbations between electronic states, hyperfine structure, rotational g factors, dipole moments, radiative lifetimes, oscillator strengths, dissociation energies and ionization potentials when available, and other aspects. Herzberg received the 1971 Nobel Prize in Chemistry; both authors are world-renowned highly respected scientists.

Using observations of the near Earth asteroid Eros from 1926 to 1945, German- American astronomer Eugene K. Rabe was able to make an independent estimate the mass of Mars, as well as the other planets in the inner Solar System, from the planet's gravitational perturbations of the asteroid. His estimated margin of error was 0.05%, but subsequent checks suggested his result was poorly determined compared to other methods. During the 1920s, French astronomer Bernard Lyot used a polarimeter to study the surface properties of the Moon and planets. In 1929, he noted that the polarized light emitted from the Martian surface is very similar to that radiated from the Moon, although he speculated that his observations could be explained by frost and possibly vegetation.

In 2008 Tadashi Mukai and Patryk Sofia Lykawka suggested a distant Mars- or Earth-sized planet, currently in a highly eccentric orbit between 100 and and orbital period of 1000 years with an inclination of 20° to 40°, was responsible for the structure of the Kuiper belt. They proposed that the perturbations of this planet excited the eccentricities and inclinations of the trans-Neptunian objects, truncated the planetesimal disk at 48 AU, and detached the orbits of objects like Sedna from Neptune. During Neptune's migration this planet is posited to have been captured in an outer resonance of Neptune and to have evolved into a higher perihelion orbit due to the Kozai mechanism leaving the remaining trans-Neptunian objects on stable orbits.

In the case of raising the temperature, mantle melting will only occur if the mantle is heated past the normal geotherm. It is believed that heat flux from the core and lower mantle is responsible for increasing the temperature of the upper mantle. Local perturbations of the geothermal gradient, such as hotspots, are not well understood but are considered to be a likely heat source for the mantle.The decay of radioactive elements, though considered to be one of the simplest ways of generating heat in the mantle, is not realistically responsible for mantle melting, as it would take over 10 million years for the radioactive decay of K, U and Th to increase the temperature of peridotite by 1 degree Celsius.

Lake and Mulga ecosystems with alternative stable states In ecology, resilience is the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and recovering quickly. Such perturbations and disturbances can include stochastic events such as fires, flooding, windstorms, insect population explosions, and human activities such as deforestation, fracking of the ground for oil extraction, pesticide sprayed in soil, and the introduction of exotic plant or animal species. Disturbances of sufficient magnitude or duration can profoundly affect an ecosystem and may force an ecosystem to reach a threshold beyond which a different regime of processes and structures predominates. When such thresholds are associated with a critical or bifurcation point, these regime shifts may also be referred to as critical transitions.

One suggested pathway for the Big Splash as viewed from the direction of the south pole (not to scale). In 2004, Princeton University mathematician Edward Belbruno and astrophysicist J. Richard Gott III proposed that Theia coalesced at the or Lagrangian point relative to Earth (in about the same orbit and about 60° ahead or behind), similar to a trojan asteroid. Two-dimensional computer models suggest that the stability of Theia's proposed trojan orbit would have been affected when its growing mass exceeded a threshold of approximately 10% of the Earth's mass (the mass of Mars). In this scenario, gravitational perturbations by planetesimals caused Theia to depart from its stable Lagrangian location, and subsequent interactions with proto-Earth led to a collision between the two bodies.

Star cluster Pismis 24 with a nebula One of the oldest fields in astronomy, and in all of science, is the measurement of the positions of celestial objects. Historically, accurate knowledge of the positions of the Sun, Moon, planets and stars has been essential in celestial navigation (the use of celestial objects to guide navigation) and in the making of calendars. Careful measurement of the positions of the planets has led to a solid understanding of gravitational perturbations, and an ability to determine past and future positions of the planets with great accuracy, a field known as celestial mechanics. More recently the tracking of near-Earth objects will allow for predictions of close encounters or potential collisions of the Earth with those objects.

His contributions in the field of electrical engineering began with the completion of his PhD at MIT under the supervision of Prof. Fred Schweppe, in which he formulated a new technique for the dynamic analysis of small perturbations of electric power systems known as Selective Modal Analysis. This analytical framework allows approaching large and complex linear time-invariant dynamic system problems (such as dynamic stability analysis, or the determination of coherent generator groups and dynamic equivalents in transient stability studies) through a reduction technique that extracts the relevant quantitative and qualitative information. This framework was later applied intensively to solve different power system stability and control problems, such as the analysis of the oscillatory stability and control, subsynchronous resonance or multi-area analysis of small signal stability.

Some literatures do not consider Taylor microscales as a characteristic length scale and consider the energy cascade to contain only the largest and smallest scales; while the latter accommodate both the inertial subrange and the viscous sublayer. Nevertheless, Taylor microscales are often used in describing the term "turbulence" more conveniently as these Taylor microscales play a dominant role in energy and momentum transfer in the wavenumber space. Although it is possible to find some particular solutions of the Navier–Stokes equations governing fluid motion, all such solutions are unstable to finite perturbations at large Reynolds numbers. Sensitive dependence on the initial and boundary conditions makes fluid flow irregular both in time and in space so that a statistical description is needed.

Consequently, the watershed is a foundational environmental resource, providing the region with many goods and services including jobs, natural materials (timber, fresh water), and recreation at a capital worth recently estimated to be $198 billion annually. However, the efficacy and ability of the system to provide these assets largely hinges upon the function of such essential ecosystem components like nutrient cycling. Perturbations to nutrient cycling may result in deleterious effects to both the environment and to resident human populations, possibly through the emergence of toxic plankton blooms, decreased aesthetic value, dissolved oxygen depletion, and reduced fish stocks. Ultimately, the sustainability of the Columbia River Basin ecosystem and its impact on residents are firmly connected by the function of nutrient cycles.

This example is also one of many trajectories and gains of speed the spaceship can have. This explanation might seem to violate the conservation of energy and momentum, apparently adding velocity to the spacecraft out of nothing, but the spacecraft's effects on the planet must also be taken into consideration to provide a complete picture of the mechanics involved. The linear momentum gained by the spaceship is equal in magnitude to that lost by the planet, so the spacecraft gains velocity and the planet loses velocity. However, the planet's enormous mass compared to the spacecraft makes the resulting change in its speed negligibly small even when strictly compared to the orbital perturbations planets undergo due to interactions with other celestial bodies on astronomically short timescales.

The Perturb-seq protocol uses CRISPR technology to inactivate specific genes and DNA barcoding of each guide RNA to allow for all perturbations to be pooled together and later deconvoluted, with assignment of each phenotype to a specific guide RNA. Droplet-based microfluidics platforms (or other cell sorting and separating techniques) are used to isolate individual cells, and then scRNA-seq is performed to generate gene expression profiles for each cell. Upon completion of the protocol, bioinformatics analyses are conducted to associate each specific cell and perturbation with a transcriptomic profile that characterizes the consequences of inactivating each gene. In the December 2016 issue of the Cell journal, two companion papers were published that each introduced and described this technique.

E. Ott, C. Grebogi and J. A. Yorke were the first to make the key observation that the infinite number of unstable periodic orbits typically embedded in a chaotic attractor could be taken advantage of for the purpose of achieving control by means of applying only very small perturbations. After making this general point, they illustrated it with a specific method, since called the OGY method (Ott, Grebogi and Yorke) of achieving stabilization of a chosen unstable periodic orbit. In the OGY method, small, wisely chosen, kicks are applied to the system once per cycle, to maintain it near the desired unstable periodic orbit. To start, one obtains information about the chaotic system by analyzing a slice of the chaotic attractor.

Depending on what time frames are considered, perturbations can appear secular even if they are actually periodic. An example of this is the precession of the Earth's axis considered over the time frame of a few hundred or thousand years. When viewed in this time frame the so-called "precession of the equinoxes" can appear to mimic a secular phenomenon since the axial precession takes 25,771.5 years and monitoring it over a much smaller timeframe appears to simply result in a "drift" of the position of the equinox in the plane of the ecliptic of approximately one degree every 71.6 years, influencing the Milankovitch cycles.Jurij B. Kolesnik; A new approach to interpretation of the non-precessional equinox motion, in Journées 2000 - systèmes de référence spatio-temporels.

Based on its calculated temperature and age, it is classified under the brown dwarf spectral type L7. The team leader, Michael Liu of the Institute for Astronomy at the University of Hawaii, stated: "We have never before seen an object free-floating in space that looks like this. It has all the characteristics of young planets found around other stars, but it is drifting out there all alone."Young planet, six times more massive than Jupiter, found hanging alone without star Shelly Jones, Pentagon Post, 12 October 2013 Current theories about such objects include the possibility that gravitational perturbations may have kicked them out of their planetary systems soon after they formed through planetary accretion, or they may have been formed by some other means.

Le Chatelier's principle (pronounced or ), also called Chatelier's principle or "The Equilibrium Law", is a principle of chemistry used to predict the effect of a change in conditions on chemical equilibria. The principle is named after French chemist Henry Louis Le Chatelier, and sometimes also credited to Karl Ferdinand Braun, who discovered it independently. It can be stated as: It is common to treat the principle as a more general observation of systems, such as or, "roughly stated", The concept of systemic maintenance of an equilibrium state despite perturbations has a variety of names, depending upon the discipline using it (e.g. homeostasis, an idea which encompasses the concept, is commonly used in biology), and has been studied in a variety of contexts, chiefly in the natural sciences.

Volcanic "injection" Natural sulfur aerosols are formed in vast quantities from the SO2 ejected by volcanoes, which may be injected directly into the stratosphere during very large (Volcanic Explosivity Index, VEI, of 4 or greater) eruptions. A comprehensive analysis, dealing largely with tropospheric sulfur compounds in the atmosphere, is provided by Bates et al. The IPCC AR4 says explosive volcanic events are episodic, but the stratospheric aerosols resulting from them yield substantial transitory perturbations to the radiative energy balance of the planet, with both shortwave and longwave effects sensitive to the microphysical characteristics of the aerosols. During periods lacking volcanic activity (and thus direct injection of SO2 into the stratosphere), oxidation of COS (carbonyl sulfide) dominates the production of stratospheric sulfur aerosol.

The other major problem plaguing the achievement of high symmetry and high temperatures/densities of the imploding target are so called "beam-beam" imbalance and beam anisotropy. These problems are, respectively, where the energy delivered by one beam may be higher or lower than other beams impinging on the target and of "hot spots" within a beam diameter hitting a target which induces uneven compression on the target surface, thereby forming Rayleigh-Taylor instabilities in the fuel, prematurely mixing it and reducing heating efficacy at the time of maximum compression. The Richtmyer-Meshkov instability is also formed during the process due to shock waves being formed. An Inertial confinement fusion target, which was a foam filled cylindrical target with machined perturbations, being compressed by the Nova Laser.

The two stars take approximately 40 days to complete an orbit around their common centre of mass. Given the extremely distorted shape of the primary, the relative orbital motion may be notably altered with respect to the two-body purely Keplerian scenario because of non-negligible long-term orbital perturbations affecting, for example, its orbital period. In other words, Kepler's third law, which holds exactly only for two point-like masses, would no longer be valid for the Regulus system. Regulus A was long thought to be fairly young, only 50 – 100 million years old, calculated by comparing its temperature, luminosity, and mass. The existence of a white dwarf companion would mean that the system is at least 1 billion years old, just to account for the formation of the white dwarf.

Two views of Larissa imaged by Voyager 2 The fourth-largest satellite of Neptune, Larissa is irregular (non- spherical) in shape and appears to be heavily cratered, with no sign of any geological modification. It is likely that Larissa, like the other satellites inward of Triton, is a rubble pile re-accreted from fragments of Neptune's original satellites, which were disrupted by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit. Larissa's orbit is nearly circular and lies below Neptune's synchronous orbit radius, so it is slowly spiralling inward due to tidal deceleration and may eventually impact Neptune's atmosphere, or break up into a planetary ring upon passing its Roche limit due to tidal stretching, similarly to how Triton will eventually collide with Neptune or break into a planetary ring.

The innermost portion of the scattered disc overlaps with a torus-shaped region of orbiting objects traditionally called the Kuiper belt, but its outer limits reach much farther away from the Sun and farther above and below the ecliptic than the Kuiper belt proper. Because of its unstable nature, astronomers now consider the scattered disc to be the place of origin for most periodic comets in the Solar System, with the centaurs, a population of icy bodies between Jupiter and Neptune, being the intermediate stage in an object's migration from the disc to the inner Solar System. Eventually, perturbations from the giant planets send such objects towards the Sun, transforming them into periodic comets. Many objects of the proposed Oort cloud are also thought to have originated in the scattered disc.

Whereas Hawking and Ellis employ global analysis extensively but say relatively little about perturbative methods, the other two books neglect global analysis and cover in great detail perturbations. He believed Hawking and Ellis did a great job summarizing recent developments in the field (as of 1974) and that the intended audience is a doctoral student (or higher) with a strong mathematical background and prior exposure to general relativity. He argued that the core of the books consists of two chapters, Chapter 4 on the significance of space-time curvature and Chapter 6 on causal structure, and that the most interesting application is the penultimate chapter on black holes. He noted that mathematical arguments are at times difficult to follow and suggested Techniques of Differential Topology in Relativity by Roger Penrose for reference.

If Neptune's migration is slow enough following this encounter the eccentricity distribution of these objects can be truncated by a sweeping mean-motion resonances, leaving it with a step near Neptune's 7:4 resonance. As Neptune slowly approaches its current orbit, objects are left in fossilized high- perihelion orbits in the scattered disk. Others with perihelia beyond Neptune's orbit but not high enough to avoid interactions with Neptune remain as a scattering objects, and those that remain in resonance at the end of Neptune's migration form the various resonant populations beyond Neptune's orbit. Objects that are scattered to very large semi-major axis orbits can have their perihelia lifted beyond the influences of the giant planets by the galactic tide or perturbations from passing stars, depositing them in the Oort cloud.

Arumberia has been interpreted as a microbial mat morphotype developed in response to environmental perturbations in terminal Ediacaran shallow marine basins Conversely, a non biological interpretation has been put forward Past experiments reproduced Arumberia-like traces from flume experiments and from the flux of water around small objects. The absence of Arumberia-like structures after the Ediacaran period could be due to the unique properties of the microbial mat that covered the sea floor at the period. However, there is still debate, with recent analysis of Urals' Arumberia-like structures leaning towards a biological interpretation as an organism adapted to shallow water environments. The rugae of Arumberia are considered to form from exclusively biological processes as observed in modern microbial mats and not from sediment desiccation, cracking or other abiotic processes.

The squadron initially made orbital predictions by computing ephemerides based on standard Kepler orbits. As a satellite got lower into the atmosphere, drag made it difficult to forecast the ephemeris of the satellite accurately.Cotter, Lawrence R.. Reminiscences About Space Track History. Privately published. Berkeley CA, 20 November 2006. By 1962, the situation was somewhat better. The Soviet satellite Sputnik 4 was slowly entering lower orbits because of atmospheric drag. Using a new program, (Satellite General Perturbations Differential Corrections) and observations from the radar at Shemya Air Force Station, the orbital analyst plotted the changing orbital period and was able to predict the exact revolution on which the satellite reentered the atmosphere.A 20-pound piece of it landed on a street in downtown Manitowoc, Wisconsin on the western shore of Lake Michigan.

Perturbations by Earth and Venus will increase the orbital uncertainty over time. When the asteroid only had an observation arc of 5 days, virtual clones of the asteroid that fit the uncertainty region in the known trajectory showed a 1 in 2,700 chance that the asteroid could impact Earth on 14 February 2030. With a 2030 Palermo Technical Scale of −2.94, the odds of impact by in 2030 were about 870 times less than the background hazard level of Earth impacts which is defined as the average risk posed by objects of the same size or larger over the years until the date of the potential impact. The power of such an air burst would be somewhere between the Chelyabinsk meteor and the Tunguska event depending on the actual size of the asteroid.

A black string is a higher dimensional (D>4) generalization of a black hole in which the event horizon is topologically equivalent to S2 × S1 and spacetime is asymptotically Md−1 × S1. Perturbations of black string solutions were found to be unstable for L (the length around S1) greater than some threshold L′. The full non-linear evolution of a black string beyond this threshold might result in a black string breaking up into separate black holes which would coalesce into a single black hole. This scenario seems unlikely because it was realized a black string could not pinch off in finite time, shrinking S2 to a point and then evolving to some Kaluza–Klein black hole. When perturbed, the black string would settle into a stable, static non-uniform black string state.

The similarity of its orbit with Earth was also very difficult to explain from natural sources, with ejecta from a recent Lunar impact or non-gravitational perturbations such as the Yarkovsky effect having been suggested. The first Earth Trojan asteroid, , was later identified and such objects could well be a source for objects like 1991 VG. 1991 VG has been a transient co-orbital of the horseshoe type in the past and it will return as such in the future; it was a natural satellite of Earth for about a month since 1992. This temporary capture may have taken place multiple times in the past and it is expected to repeat again in the future. It had an eccentricity of less than 1 with respect to the Earth from 23 February to 21 March 1992.

More recent closeup images from the Cassini probe show that the F Ring consists of one core ring and a spiral strand around it. They also show that when Prometheus encounters the ring at its apoapsis, its gravitational attraction creates kinks and knots in the F Ring as the moon 'steals' material from it, leaving a dark channel in the inner part of the ring (see video link and additional F Ring images in gallery). Since Prometheus orbits Saturn more rapidly than the material in the F ring, each new channel is carved about 3.2 degrees in front of the previous one. In 2008, further dynamism was detected, suggesting that small unseen moons orbiting within the F Ring are continually passing through its narrow core because of perturbations from Prometheus.

Ladanyi's work improved our understanding of the molecular mechanisms of solvation dynamics and their dependence on the solute, the solvent, and the perturbation in solute-solvent interactions. She was the first to show that the solvent's response is highly nonlinear for a variety of solutes in hydrogen bonding solvents and that solute-solvent hydrogen-bond formation is an important solvation mechanism in these systems. She developed methods, including instantaneous normal mode analysis, to uncover mechanistic information about solvation in systems that exhibit approximately linear response. With the advent of ultrafast spectroscopic techniques, the short- time nondiffusive dynamics in liquids became experimentally accessible and Ladanyi actively developed and implemented the theoretical framework for identifying and analyzing the molecular mechanisms contributing to the short- time response of fluids to perturbations relevant to experimental probes.

Size comparison of Neptune's seven inner moons The mass distribution of the Neptunian moons is the most lopsided of the satellite systems of the giant planets in the Solar System. One moon, Triton, makes up nearly all of the mass of the system, with all other moons together comprising only one third of one percent. The reason for the lopsidedness of the present Neptunian system is that Triton was captured from the Kuiper belt well after the formation of Neptune's original satellite system, much of which was destroyed in the process of capture. Triton's orbit upon capture is presumed to have been highly eccentric, which would have caused chaotic perturbations in the orbits of the original inner Neptunian satellites, leading to the ejection of some moons and the collisional destruction of others.

The following example is an ensemble of data from 2D incompressible Navier–Stokes simulation consisting of 40 members, where each ensemble member is a simulation with Reynolds number and inlet velocity chosen randomly. The inlet velocity values are randomly drawn from a normal distribution with mean value of 1 and standard deviation of ±0.01 (in non- dimensionalized units); likewise, Reynolds numbers are generated from a normal distribution with mean value of 130 and standard deviation of ±3. The example below is from an ensemble of publicly available data from the National Oceanic and Atmospheric Administration (NOAA) [1]. The ensemble data are formed through different runs of a simulation model with different perturbations of the initial conditions to account for the errors in the initial conditions and/or model parameterizations.

An elliptic Kepler orbit with an eccentricity of 0.7, a parabolic Kepler orbit and a hyperbolic Kepler orbit with an eccentricity of 1.3. The distance to the focal point is a function of the polar angle relative to the horizontal line as given by the equation () In celestial mechanics, a Kepler orbit (or Keplerian orbit, named after the German astronomer Johannes Kepler) is the motion of one body relative to another, as an ellipse, parabola, or hyperbola, which forms a two-dimensional orbital plane in three-dimensional space. A Kepler orbit can also form a straight line. It considers only the point-like gravitational attraction of two bodies, neglecting perturbations due to gravitational interactions with other objects, atmospheric drag, solar radiation pressure, a non-spherical central body, and so on.

However, if the moment of inertia around one of the two axes close to the equator becomes nearly equal to that around the polar axis, the constraint on the orientation of the object (the Earth) is relaxed. This situation is like a rugby football or an American football spinning around an axis running through its "equator". (Note that the "equator" of the ball does not correspond to the equator of the Earth.) Small perturbations can move the football, which then spins around another axis through the same "equator". In the same way, conditions can make the Earth (both the crust and the mantle) slowly reorient until a new geographic point moves to the North Pole, with the axis of low moment of inertia being kept very near the equator.

Dynamically, the Kreutz sungrazers might continue to be recognised as a distinct family for many thousands of years yet. Eventually, their orbits will be dispersed by gravitational perturbations, although depending on the rate of fragmentation of the constituent parts, the group might be completely destroyed before it is gravitationally dispersed. The continuing discovery of large numbers of the smaller members of the family by SOHO will undoubtedly lead to a greater understanding of how comets break up to form families. It is not possible to estimate the chances of another very bright Kreutz comet arriving in the near future, but given that at least 10 have reached naked-eye visibility over the last 200 years, another great comet from the Kreutz family seems almost certain to arrive at some point.

Seismic waves are mechanical perturbations that travel in the Earth at a speed governed by the acoustic impedance of the medium in which they are travelling. The acoustic (or seismic) impedance, Z, is defined by the equation: :Z=V\rho \ , where V is the seismic wave velocity and ρ (Greek rho) is the density of the rock. When a seismic wave travelling through the Earth encounters an interface between two materials with different acoustic impedances, some of the wave energy will reflect off the interface and some will refract through the interface. At its most basic, the seismic reflection technique consists of generating seismic waves and measuring the time taken for the waves to travel from the source, reflect off an interface and be detected by an array of receivers (or geophones) at the surface.

These results imply that the Arabian Sea is highly vulnerable to potential anthropogenic perturbations. As a part of his pioneering efforts to investigate the impacts of global change on marine biogeochemistry of the northern Indian Ocean, Naqvi carried out extensive work on greenhouse gases [carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4)] both in the open-ocean and seasonally-occurring coastal hypoxic zone. The coastal low-oxygen zone, the largest of its kind in the world, has been found to have intensified in recent years, affecting living resources and providing feedback to global change. The former is because denitrification removes all nitrate, at rates that are the highest ever measured from any marine system, culminating in sulphidic conditions, and the latter is due to unprecedented accumulation of N2O.

If the combination of genetic events results in a non-lethal reduction in fitness, the interaction is called synthetic sickness. Although in classical genetics the term synthetic lethality refers to the interaction between two genetic perturbations, synthetic lethality can also apply to cases in which the combination of a mutation and the action of a chemical compound causes lethality, whereas the mutation or compound alone are non-lethal. Synthetic lethality is a consequence of the tendency of organisms to maintain buffering schemes that allow phenotypic stability despite genetic variation, environmental changes and random events such as mutations. This genetic robustness is the result of parallel redundant pathways and "capacitor" proteins that camouflage the effects of mutations so that important cellular processes do not depend on any individual component.

Extreme examples of complex quantum entanglement arise in metallic states of matter without quasiparticle excitations, often called strange metals. Remarkably, there is an intimate connection between the quantum physics of strange metals found in modern materials (which can be studied in tabletop experiments), and quantum entanglement near black holes of astrophysics. This connection is most clearly seen by first thinking more carefully about the defining characteristic of a strange metal: the absence of quasiparticles. In practice, given a state of quantum matter, it is difficult to completely rule out the existence of quasiparticles: while one can confirm that certain perturbations do not create single quasiparticle excitations, it is almost impossible to rule out a non-local operator which could create an exotic quasiparticle in which the underlying electrons are non-locally entangled.

This method involves analyzing multiple forecasts created with an individual forecast model by using different physical parametrizations or varying initial conditions. Starting in 1992 with ensemble forecasts prepared by the European Centre for Medium-Range Weather Forecasts (ECMWF) and the National Centers for Environmental Prediction, model ensemble forecasts have been used to help define the forecast uncertainty and to extend the window in which numerical weather forecasting is viable farther into the future than otherwise possible. The ECMWF model, the Ensemble Prediction System, uses singular vectors to simulate the initial probability density, while the NCEP ensemble, the Global Ensemble Forecasting System, uses a technique known as vector breeding. The UK Met Office runs global and regional ensemble forecasts where perturbations to initial conditions are produced using a Kalman filter.

In practice the satellite drifts out of this orbit because of perturbations such as the solar wind, radiation pressure, variations in the Earth's gravitational field, and the gravitational effect of the Moon and Sun, and thrusters are used to maintain the orbit in a process known as station-keeping. Eventually, without the use of thrusters, the orbit will become inclined, oscillating between 0° and 15° every 55 years. At the end of the satellite's lifetime, when fuel approaches depletion, satellite operators may decide to omit these expensive manoeuvres to correct inclination and only control eccentricity. This prolongs the life- time of the satellite as it consumes less fuel over time, but the satellite can then only be used by ground antennas capable of following the N-S movement.

Collisions between ice and soft hail (graupel) inside cumulonimbus clouds causes separation of positive and negative charges within the cloud, essential for the generation of lightning. How lightning initially forms is still a matter of debate: Scientists have studied root causes ranging from atmospheric perturbations (wind, humidity, and atmospheric pressure) to the impact of solar wind and energetic particles. An average bolt of lightning carries a negative electric current of 40 kiloamperes (kA) (although some bolts can be up to 120 kA), and transfers a charge of five coulombs and energy of 500 MJ, or enough energy to power a 100-watt lightbulb for just under two months. The voltage depends on the length of the bolt, with the dielectric breakdown of air being three million volts per meter, and lightning bolts often being several hundred meters long.

The mission aims to study the existence of possible (temporal and spatial) correlations between the observation of iono- magnetospheric perturbations as well as precipitation of particles from the inner Van Allen belts and the occurrence of seismic events. However, a careful analysis is needed in order to distinguish measurements possibly associated to earthquakes from the large background generated in the geomagnetic cavity by the solar activity and the tropospheric electromagnetic emissions. CSES mission will investigate the structure and the dynamics of the topside ionosphere, the coupling mechanisms between upper atmosphere, ionosphere and magnetosphere and the temporal variations of the geomagnetic field, in quiet and disturbed conditions. Data collected by the mission will also allow to studying solar-terrestrial interactions and phenomena of solar physics, namely Coronal Mass Ejections (CMEs), solar flares and cosmic ray solar modulation.

Tonearm skating forces and other perturbations are also picked up by the stylus. This is a form of frequency multiplexing as the control signal (restoring force) used to keep the stylus in the groove is carried by the same mechanism as the sound itself. Subsonic frequencies below about 20 Hz in the audio signal are dominated by tracking effects, which is one form of unwanted rumble ("tracking noise") and merges with audible frequencies in the deep bass range up to about 100 Hz. High fidelity sound equipment can reproduce tracking noise and rumble. During a quiet passage, woofer speaker cones can sometimes be seen to vibrate with the subsonic tracking of the stylus, at frequencies as low as just above 0.5 Hz (the frequency at which a rpm record turns on the turntable; Hz exactly on an ideal turntable).

The fact that the Earth's gravitational field slightly deviates from being spherically symmetrical also affects the orbits of satellites through secular orbital precessions. They depend on the orientation of the Earth's symmetry axis in the inertial space, and, in the general case, affect all the Keplerian orbital elements with the exception of the semimajor axis. If the reference z axis of the coordinate system adopted is aligned along the Earth's symmetry axis, then only the longitude of the ascending node Ω, the argument of pericenter ω and the mean anomaly M undergo secular precessions. Such perturbations, which were earlier used to map the Earth's gravitational field from space, may play a relevant disturbing role when satellites are used to make tests of general relativity because the much smaller relativistic effects are qualitatively indistinguishable from the oblateness-driven disturbances.

It appeared to be in orbit around the Earth, and was soon discovered from spectral analysis to be covered in white titanium dioxide, which was a major constituent of the paint used on the Saturn V. Calculation of orbital parameters led to tentative identification as being the Apollo 12 S-IVB stage. Mission controllers had planned to send Apollo 12's S-IVB into solar orbit after separation from the Apollo spacecraft, but it is believed the burn lasted too long, and hence did not send it close enough to the Moon, so it remained in a barely stable orbit around the Earth and Moon. In 1971, through a series of gravitational perturbations, it is believed to have entered in a solar orbit and then returned into weakly captured Earth orbit 31 years later. It left Earth orbit again in June 2003.

Kruger 60 has been proposed as the origin of interstellar comet 2I/Borisov (formerly named C/2019 Q4 (Borisov)) by Dybczyński, Królikowska, and Wysoczańska. These authors have from other work a list of stars and stellar systems that can potentially act as perturbers of the Oort cloud comets, and searched it for a past close proximity of 2I/Borisov at a very small relative velocity. While hampered by continuing uncertainty about the orbit of 2I/Borisov and particularly its non-gravitational acceleration (due to cometary outgassing), they reach a conclusion that 1 Myr ago 2I/Borisov passed Kruger 60 at a small distance of 1.74 pc while having an extremely small relative velocity of 3.43 km/s. Perturbations of the 2I/Borisov's incoming orbit altered the intersection distance with relatively small changes in the relative velocity.

The orbit of this asteroid is shown in blue when it is above (north of) the plane of the orbit of Jupiter, and it is shown in magenta when it is below (south of) the plane of the orbit of Jupiter. Perturbations from Jupiter maintain the stability of this orbit over millions of years. Simulations show that it has been in its co-orbital relation with Jupiter for at least a million years and will continue for at least another million years. It is somewhat of a mystery how this asteroid (or comet) got into this orbit, but it is thought that at some time in the distant past it was put into an orbit resembling its present orbit by an interaction with Saturn, and then its orbit was perturbed into the state it is in today.

It was believed that gravitational perturbations caused by the orbiting parent stars would cause any circumbinary planets to collide with each other or be ejected out of orbit, either into one of the parent stars or away from the system. However, this discovery demonstrates that multiple planets can form around binary stars, even in their habitable zones; and while the planets in the Kepler-47 system are unlikely to harbor life, other planets orbiting around binary star systems may be habitable and could support life. Because most stars are binary, the discovery that multi-planet systems can form in such a system has impacted previous theories of planetary formation, and could provide more opportunities for finding potentially habitable exoplanets. The binary system is known to host three planets, all orbiting close to each other and larger than Earth, with no solid surface.

Precise observations of Saturn's orbit using data from Cassini suggest that Planet Nine could not be in certain sections of its proposed orbit because its gravity would cause a noticeable effect on Saturn's position. This data neither proves nor disproves that Planet Nine exists. An initial analysis by Fienga, Laskar, Manche, and Gastineau using Cassini data to search for Saturn's orbital residuals, small differences with its predicted orbit due to the Sun and the known planets, was inconsistent with Planet Nine being located with a true anomaly, the location along its orbit relative to perihelion, of −130° to −110° or −65° to 85°. The analysis, using Batygin and Brown's orbital parameters for Planet Nine, suggests that the lack of perturbations to Saturn's orbit is best explained if Planet Nine is located at a true anomaly of .

Primordial gravitational waves are gravitational waves that could be observed in the polarisation of the cosmic microwave background and having their origin in the early universe. Models of cosmic inflation predict that such gravitational waves should appear; thus, their detection supports the theory of inflation, and their strength can confirm and exclude different models of inflation. It is the result of three things: inflationary expansion of space itself, reheating after inflation, and turbulent fluid mixing of matter and radiation. On 17 March 2014 it was announced that the BICEP2 instrument had detected the first type of B-modes, consistent with inflation and gravitational waves in the early universe at the level of , which is the amount of power present in gravitational waves compared to the amount of power present in other scalar density perturbations in the very early universe.

The habitable zone of the Kepler-16 system extends from approximately 55 to 106 million kilometers away from the binary system. Kepler-16b, with an orbit of about 104 million kilometers, lies near the outer edge of this habitable zone. Although the chances of life on the gas giant itself are remote, simulations conducted by researchers at the University of Texas suggest that sometime in the system's history, perturbations from other bodies could have caused an Earth-sized planet from the center of the habitable zone to migrate out of its orbit, allowing Kepler-16b to capture it as its moon. Furthermore, the researchers also considered the possibility of a faraway habitable planet orbiting at about 140 million kilometers away, which could retain the thermal energy needed to keep water liquid through a thick mixture of greenhouse gases including carbon dioxide and methane.

Another model hypothesizes that before the first stars, large gas clouds could collapse into a "quasi-star", which would in turn collapse into a black hole of around . These stars may have also been formed by dark matter halos drawing in enormous amounts of gas by gravity, which would then produce supermassive stars with tens of thousands of solar masses. The "quasi-star" becomes unstable to radial perturbations because of electron-positron pair production in its core and could collapse directly into a black hole without a supernova explosion (which would eject most of its mass, preventing the black hole from growing as fast). An alternative scenario predicts that large high-redshift clouds of metal-free gas, when irradiated by a sufficiently intense flux of Lyman-Werner photons, can avoid cooling and fragmenting, thus collapsing as a single object due to self-gravitation.

However, strategy is in fact inevitable when a voter decides their "approval cutoff"; this is a variation of the compromising strategy. Overall, Steven Brams and Dudley R. Herschbach argued in a paper in Science magazine in 2001 that approval voting was the method least amenable to tactical perturbations. Meanwhile, Balinski and Laraki used rated ballots from a poll of the 2007 French presidential election to show that, if unstrategic voters only approved candidates whom they considered "very good" or better, strategic voters would be able to sway the result frequently, but that if unstrategic voters approved all candidates they considered "good" or better, approval was the second most strategy- resistant method of the ones they studied. Approval voting forces voters to face an initial voting tactical decision as to whether to vote for (or approve) of their second-choice candidate or not.

Perturb-seq makes use of current technologies in molecular biology to integrate a multi-step workflow that couples high-throughput screening with complex phenotypic outputs. When compared to alternative methods used for gene knockdowns or knockouts, such as RNAi, zinc finger nucleases or transcription activator-like effector nucleases (TALENs), the application of CRISPR-based perturbations enables more specificity, efficiency and ease of use. Another advantage of this protocol is that while most screening approaches can only assay for simple phenotypes, such as cellular viability, scRNA-seq allows for a much richer phenotypic readout, with quantitative measurements of gene expression in many cells simultaneously. However, while a large and comprehensive amount of data can be a benefit, it can also present a major challenge. Single cell RNA expression readouts are known to produce ‘noisy’ data, with a significant number of false positives.

The Lazarus project (1998–2005) was developed as a post-Grand Challenge technique to extract astrophysical results from short lived full numerical simulations of binary black holes. It combined approximation techniques before (post-Newtonian trajectories) and after (perturbations of single black holes) with full numerical simulations attempting to solve General Relativity field equations. All previous attempts to numerically integrate in supercomputers the Hilbert- Einstein equations describing the gravitational field around binary black holes led to software failure before a single orbit was completed. The Lazarus approach, in the meantime, gave the best insight into the binary black hole problem and produced numerous and relatively accurate results, such as the radiated energy and angular momentum emitted in the latest merging state, the linear momentum radiated by unequal mass holes, and the final mass and spin of the remnant black hole.

Because of this gradient, galactic tides may then deform an otherwise spherical Oort cloud, stretching the cloud in the direction of the galactic centre and compressing it along the other two axes, just as the Earth distends in response to the gravity of the Moon. The Sun's gravity is sufficiently weak at such a distance that these small galactic perturbations may be enough to dislodge some planetesimals from such distant orbits, sending them towards the Sun and planets by significantly reducing their perihelia. Such a body, being composed of a rock and ice mixture, would become a comet when subjected to the increased solar radiation present in the inner Solar System. It has been suggested that the galactic tide may also contribute to the formation of an Oort cloud, by increasing the perihelia of planetesimals with large aphelia.

He then accepted a position as a senior engineer at Elbit Systems, a military defense contractor located near Haifa, Israel, where he modeled trajectories and flight profiles of missiles launched from a fixed-wing aircraft. While at Elbit, Isser continued his studies at the Technion on a part-time basis under the guidance of Professor Aviv Rosen. In 1995, Isser completed his Ph-D in Aeronautical Engineering and successfully defended his thesis, entitled "The Influence of Variations in the Locations of the Blades of a Hovering Helicopter on the Aerodynamic Loads Developed during Perturbations about Axial Flight".Aharon Isser's Ph-D Thesis Title That same year, Isser died on April 9, 1995, in a tragic accident, but his pioneering work in air foil modeling has paved the way for more aerodynamically efficient designs for helicopter rotors and other rotorcraft platforms.

Accuracy is not a great concern here as high drag satellite cases do not remain in "deep space" for very long as the orbit quickly becomes lower and near circular. SDP4 also adds Lunar–Solar gravity perturbations to all orbits, and Earth resonance terms specifically for 24-hour geostationary and 12-hour Molniya orbits. Additional revisions of the model were developed and published by 2010 by the NASA Goddard Space Flight Center in support of tracking of the SeaWiFS mission and the Navigation and Ancillary Information Facility at the Jet Propulsion Laboratory in support of Planetary Data System for navigational purposes of numerous, mostly deep space, missions. Current code libraries use SGP4 and SDP4 algorithms merged into a single codebase in 1990 handling the range of orbital periods which are usually referred to generically as SGP4.

Because the third dimension involves not only distance but cosmic time, tomographic weak lensing is sensitive not only to the matter power spectrum today, but also to its evolution over the history of the universe, and the expansion history of the universe during that time. This is a much more valuable cosmological probe, and many proposed experiments to measure the properties of dark energy and dark matter have focused on weak lensing, such as the Dark Energy Survey, Pan-STARRS, and Large Synoptic Survey Telescope. Weak lensing also has an important effect on the Cosmic Microwave Background and diffuse 21cm line radiation. Even though there are no distinct resolved sources, perturbations on the origining surface are sheared in a similar way to galaxy weak lensing, resulting in changes to the power spectrum and statistics of the observed signal.

In the preface of this monograph, Professor Michiel Hazewinkel (Series Editor) states that > the theory of stability of ordinary differential equations contains the > germs for a theory of stability of nonlinear evolution semigroups ... This > book is devoted to a self-contained systematic exposition of these matters > and incorporates many of the author's own substantial results in the field. This book has been followed by a series of related papers, including his articles on second-order evolution equations governed by monotone operators. These publications provide a complete answer to the long-standing existence question in the non-homogeneous case. Both his joint monograph on functional methods and that on singular perturbations contain original material mostly due to the authors, bringing new ideas and methods that are useful in exploring mathematical models described by linear and nonlinear differential equations.

Thus Newton gave a justification, otherwise lacking, for applying the inverse square law to large spherical planetary masses as if they were tiny particles.Propositions 70 to 75 in Book 1, for example in the 1729 English translation of the Principia, start at page 263. In addition, Newton had formulated, in Propositions 43–45 of Book 1Propositions 43 to 45 in Book 1, in the 1729 English translation of the Principia, start at page 177. and associated sections of Book 3, a sensitive test of the accuracy of the inverse square law, in which he showed that only where the law of force is calculated as the inverse square of the distance will the directions of orientation of the planets' orbital ellipses stay constant as they are observed to do apart from small effects attributable to inter-planetary perturbations.

Simulations indicate that the orbital eccentricity of Mercury varies chaotically from nearly zero (circular) to more than 0.45 over millions of years due to perturbations from the other planets. This was thought to explain Mercury's 3:2 spin-orbit resonance (rather than the more usual 1:1), because this state is more likely to arise during a period of high eccentricity. However, accurate modeling based on a realistic model of tidal response has demonstrated that Mercury was captured into the 3:2 spin-orbit state at a very early stage of its history, within 20 (more likely, 10) million years after its formation. Numerical simulations show that a future secular orbital resonant perihelion interaction with Jupiter may cause the eccentricity of Mercury's orbit to increase to the point where there is a 1% chance that the planet will collide with Venus within the next five billion years.

One unproven aspect of the reported Dogon knowledge of the Sirius system is the assertion that the Dogon knew of another star in the Sirius system, Emme Ya, or "larger than Sirius B but lighter and dim in magnitude." A dynamical study published in 1995, based on anomalous perturbations of Sirius B (suggestive of the star being gravitationally influenced by another body) concluded that the presence of a third star orbiting Sirius could not be ruled out. An apparent "third star" observed in the 1920s is now confirmed as a background object, something previously suggested by Holberg in 2007: The former study also concluded that while a triple system for Sirius could not be fully eliminated, the probability was low. Temple's book and the debates that followed its release publicized the existence of the Dogon tribe among many New Age followers and proponents of ancient astronaut theories.

There are many examples of stationary non-equilibrium systems, some very simple, like a system confined between two thermostats at different temperatures or the ordinary Couette flow, a fluid enclosed between two flat walls moving in opposite directions and defining non-equilibrium conditions at the walls. Laser action is also a non-equilibrium process, but it depends on departure from local thermodynamic equilibrium and is thus beyond the scope of classical irreversible thermodynamics; here a strong temperature difference is maintained between two molecular degrees of freedom (with molecular laser, vibrational and rotational molecular motion), the requirement for two component 'temperatures' in the one small region of space, precluding local thermodynamic equilibrium, which demands that only one temperature be needed. Damping of acoustic perturbations or shock waves are non-stationary non-equilibrium processes. Driven complex fluids, turbulent systems and glasses are other examples of non-equilibrium systems.

Image of the January 1995 system On rare occasions, tropical-like systems that can reach the intensity of hurricanes, occur over the Mediterranean Sea. Such a phenomenon is called a Medicane (Mediterranean-hurricane). Although the geographical dimensions of tropical oceans and the Mediterranean Sea are clearly different, the precursor mechanisms of these perturbations, based on the air-sea thermodynamic imbalance, are similar."Medicanes: cataloguing criteria and exploration of meteorological environments ". www.tethys.cat. Their origins are typically non-tropical, and develop over open waters under strong, initially cold-core cyclones, similar to subtropical cyclones or anomalous tropical cyclones in the Atlantic Basin, like Karl (1980), Vince (2005), Grace (2009), Chris (2012), or Ophelia (2017). Sea surface temperatures in late-August and early- September are quite high over the basin (24/28 °C or 75/82 °F), though research indicates water temperatures of 20 °C (68 °F) are normally required for development.