710 Sentences With "periodicity" | Random Sentence Generator

After awhile I realized that something about the periodicity of the image was affecting the periodicity of the sound.

Just like physics allows for the spontaneous formation of crystals, whose periodicity breaks the symmetry of space, so too should it allow for the spontaneous formation of time crystals, whose periodicity break the symmetry of time.

That way, they'll know if this kind of periodicity is the exception or routine behavior.

The circumstances must be different from a pulsar where the beam...is visible to the observer with an exact periodicity.

"We also did not find any particular periodicity in the data," meaning they could not recreate the DAMA/LIBRA results.

This projection does not retain the periodicity of the lattice, but it does produce long-range order, like a Penrose tiling.

In 20163, the Nobel laureate Frank Wilczek predicted that the periodicity of crystals could be extended into the fourth dimension: time.

You can select a periodicity so that your employees receive a fake phishing attempt at least once every 45 days, for instance.

We've built our lives and societies around this periodicity, with days that are divided into hours, minutes, and seconds, all kept track of by clocks.

These events do not occur with the same periodicity as earnings releases — and that's precisely why Goldman's derivatives strategists see an opening to exploit them.

Previous studies have suggested that mass extinctions may occur with regularity, and some researchers have linked this perceived periodicity to pulses of comet or asteroid strikes.

If this is true, the researchers expect to see another dimming event in June 2019, which would establish some periodicity to the otherwise unpredictable light dips.

"The discovery of a 16.35-day periodicity in a repeating FRB source is an important clue to the nature of this object," the scientists said in the paper.

"The discovery of a 16.35-day periodicity in a repeating FRB source is an important clue to the nature of this object," the researchers wrote in their study.

They hope to learn whether the bursts have their own periodicity, or intervals at which they recur, as well as discovering the true nature of the persistent radio source.

This marks the first time that scientists have ever detected periodicity in these signals, which are known as fast radio bursts (FRBs), and is a major step toward unmasking their sources.

"We conclude that this is the first detected periodicity of any kind in an FRB source," the team said in a paper published on the preprint server arXiv in late January.

Rather my claim of periodicity aims to make clear the radical divergence between what is widely understood as Street Art today and what was understood as Street Art in its infancy.

"It&aposs just a much tighter periodicity in the roll, and a lot of that has to do with the rigidness and the stability of how the ship is built," Carlson said.

The group, led by physicist Chetan Nayak, built on prior research from Princeton University, which found that time crystals can spontaneously break a fundamental symmetry called time-translation symmetry to exhibit periodicity over time.

ENSO cycles back and forth between strong and weak phases with an average periodicity of 22015 to 216 years but with repetitions varying from as little as 2 years to 7 or even 10 years.

He wrote his thesis on the topic of the "Periodicity of the World Wide Process," which examined the recurrence of certain events throughout history and the possible causes for these recurrences—in other words, why history repeats itself.

Time crystals are a new phase of matter that was first described as a mathematical oddity by the Nobel laureate Frank Wilczek in 2012, in which the periodicity of a three-dimensional spatial crystal is extended into the fourth dimension: time.

He determined that the cause of this historical periodicity to be the result of the Sun's electromagnetic influence over the Earth—in particular, he linked the regular occurrence of historical events to the solar cycle, matching battles, riots and revolutions throughout world history with particularly strong solar flares.

They also note that periodicity could arise from the rotation of a star, but that's a tricky hypothesis: Previously observed sources have had way shorter periodicities (a few hours, not a couple of weeks) and way less strength (we're talking nine orders of magnitude less) than FRBs have.

According to Naik, new threat signatures are detected by an IoT honeypot network covering different IoT device architectures; anomalies are identified by profiling individual device behavior based on parameters such as periodicity of transmissions, payload size, protocols and ports; intrusions into IoT ecosystems are detected by an integrated Intrusion Detection System (IDS); and IoT web interfaces are secured through a WAF.

Read More: Okay, WTF is a Time Crystal According to the paper published today by the Maryland team, they created a time crystal using ten trapped ytterbium ions lined up in a row, which they then hit with laser pulses to flip the spins of the ions at half the speed of the laser pulse—a periodicity that is the telltale mark of a bona fide time crystal.

Improving periodicity schedules can improve access to and utilization of child health services.Kaye N, Johnson K, May J. Improving EPSDT Periodicity Schedules to Promote Healthy Development.

This 4-fold and 8-fold periodicity in the structure of manifolds is related to the 4-fold periodicity of L-theory and the 8-fold periodicity of real topological K-theory, which is known as Bott periodicity. If a compact oriented smooth spin manifold has dimension , or exactly, then its signature is an integer multiple of 16.Ochanine, Serge, "Signature modulo 16, invariants de Kervaire généralisés et nombres caractéristiques dans la K-théorie réelle", Mém. Soc. Math. France 1980/81, no.

Schneider D, Crall JJ. EPSDT Periodicity Schedules and their Relation to Pediatric Oral Health Standards in Health Start and Early Head Start. Oral Health Policy Center. State Dental Periodicity Schedules. American Academy of Pediatric Dentistry.

The nyctitropic movement of plants affords another example of daily periodicity.

The society also periodically publishes a newsletter and other publications without fixed periodicity.

According to Rudnitskij, a 12- to 15-year "super-periodicity" has been observed. The author infers such periodicity could coincide with the revolution period of an invisible companion, probably planetary. So far no clear hint of planetary objects has been detected.

The break in periodicity results in a decrease in conductivity due to defect scattering.

Finally, the Bott periodicity theorem as formulated below extends the theories to positive integers.

Clifford algebras exhibit a 2-fold periodicity over the complex numbers and an 8-fold periodicity over the real numbers, which is related to the same periodicities for homotopy groups of the stable unitary group and stable orthogonal group, and is called Bott periodicity. The connection is explained by the geometric model of loop spaces approach to Bott periodicity: their 2-fold/8-fold periodic embeddings of the classical groups in each other (corresponding to isomorphism groups of Clifford algebras), and their successive quotients are symmetric spaces which are homotopy equivalent to the loop spaces of the unitary/orthogonal group.

The Hodge conjecture for rational cohomology is, as of 2008, a major unsolved problem. The Bott periodicity theorem was a central theme in Atiyah's work on K-theory, and he repeatedly returned to it, reworking the proof several times to understand it better. With Bott he worked out an elementary proof, and gave another version of it in his book. With Bott and Shapiro he analysed the relation of Bott periodicity to the periodicity of Clifford algebras; although this paper did not have a proof of the periodicity theorem, a proof along similar lines was shortly afterwards found by R. Wood.

Stetter-Hollingworth, L. (1914). Functional periodicity: An experimental study of the mental and motor abilities of women during menstruation. Contributions to Education, 69. The idea of functional periodicity stems from ancient taboos and rituals that were passed on from generation to generation.

Bouts of fever occurs daily (24-hour periodicity) for few hours, typical of Plasmodium knowlesi.

Fever occurs after an interval of three days (72-hour periodicity), typical of Plasmodium malariae.

It then developed into an actual theory in the twentieth century. Functional periodicity was investigated by a female psychologist named Leta Hollingworth. She made key contributions in the research of functional periodicity, as well as in the feminist movement at the time. Hollingworth, along with her husband Harry Hollingworth, established exceptional research on the idea of functional periodicity and created research studies investigating the science of motor/learning tasks involving the human body.

The Middle Miocene disruption is considered a significant extinction event and has been analyzed in terms of the importance of there being a possible periodicity between extinction events. A study from Raup and Sepkoski found that there is a statistically significant mean periodicity (where P is less than .01) of about 26 million years for 12 major extinction events. There is debate whether this potential periodicity is caused by some set of recurrent cycles or biologic factors.

The variations are erratic, but a strong 657-day periodicity was noticed in Hipparcos photometry of HR 5171\. More recent variations showed the strongest periodicity at around 3,300 days, but also showed other periods including one at 648 days. This persistent periodicity through all other variations is due to the eclipses twice every 1,304 days. It is classified in the General Catalogue of Variable Stars as a possible S Doradus variable, as well as an eclipsing variable.

The schedules for periodic well-child visits in EPSDT are known as periodicity schedules. States are required to develop schedules for periodic screening, vision, and hearing services at intervals that meet reasonable standards of medical practice. Federal law requires that states consult with recognized medical organizations involved in child health care in the development of their states’ EPSDT periodicity schedules. Alternatively, states may elect to use a nationally recognized pediatric periodicity schedule such as Bright Futures .

Her studies on functional periodicity helped to expand the view of menstruation and reduce bias towards women.

Fever occurs after an interval of two days (48-hour periodicity), typical of Plasmodium vivax and Plasmodium ovale.

In mathematics, the Bott periodicity theorem describes a periodicity in the homotopy groups of classical groups, discovered by , which proved to be of foundational significance for much further research, in particular in K-theory of stable complex vector bundles, as well as the stable homotopy groups of spheres. Bott periodicity can be formulated in numerous ways, with the periodicity in question always appearing as a period-2 phenomenon, with respect to dimension, for the theory associated to the unitary group. See for example topological K-theory. There are corresponding period-8 phenomena for the matching theories, (real) KO-theory and (quaternionic) KSp-theory, associated to the real orthogonal group and the quaternionic symplectic group, respectively.

There is a roughly periodicity in the emission that could be caused by the precession of the accretion disk.

None of these stars exhibited such dimming. In 2018, a possible periodicity in dimming of the star was reported.

Seasonality (or periodicity) can usually be assessed from an autocorrelation plot, a seasonal subseries plot, or a spectral plot.

Rigid axles back and front supported low-periodicity positively lubricated half-elliptical springs with hydraulic shock absorbers and jacks.

There are two important parameters of an optical lattice: the well depth and the periodicity. The well depth of the optical lattice can be tuned in real time by changing the power of the laser, which is normally controlled by an AOM (acousto-optic modulator). The periodicity of the optical lattice can be tuned by changing the wavelength of the laser or by changing the relative angle between the two laser beams. The real-time control of the periodicity of the lattice is still a challenging task.

Therefore, some authors have proposed that the KaiC ATPase activity constitutes the most fundamental reaction underlying circadian periodicity in cyanobacteria.

In the Bott periodicity theorem, the loop spaces of the stable orthogonal group can be interpreted as reductive symmetric spaces.

This team retracted this claim in 2002, but found a different periodicity of 7 days possibly due to stellar rotation.

The function f(u) thus has the period iω' in the imaginary direction while it is 2iω' for F(u). Their zeros and poles will again form a regular lattice reflecting their double periodicity. After Gauss had died it was discovered that he had discovered a corresponding double periodicity in his lemniscate elliptic function.

Leta Hollingworth was a clinical psychologist and feminist activist who conducted psychological research on several theories involving women. Some of these theories included the variability hypothesis and functional periodicity. She was quite instrumental in disproving the theory of functional periodicity, which was widely believed to be true by scientists as well as the general public. For her dissertation research at Columbia Teacher's College, Hollingworth decided to conduct an investigation on functional periodicity, which she considered to be an unfair assumption about women that lacked any scientific grounds to justify itself.

74, No.439, p. 286, 1962 Wehlau, W.H., Leung, Kam-Ching, "The Multiple Periodicity of Delta Delphini", ApJ Vol. 139, p.

The lightcurve of Afra shows a periodicity of hours, during which time the brightness of the object varies by in magnitude.

When she finally got the opportunity to enroll in the psychology program at Columbia University under Edward Thorndike, she took it. At the end of the program, she decided to study functional periodicity for her dissertation research. Hollingworth wanted to investigate the idea of functional periodicity and its assumptions about women. She started by designing two separate studies.

E. V. BabaevBabaev, E.V. and R. Hefferlin 1996. The Concepts of Periodicity and Hyper- periodicity: from Atoms to Molecules, in Rouvray, D.H. and Kirby, E.C., “Concepts in Chemistry,” Research Studies Press Limited, Taunton, Somerset, England. has erected a hyperperiodic system which in principle includes all of the systems described above except those of Dias, Gorski, and Jenz.

The periodicity of root regeneration potential of black and white spruce and jack pine nursery seedlings. M.Sc. thesis, Univ. Toronto, Fac. For.

The light curve of 305 Gordonia shows a periodicity of , during which time the brightness of the object varies by in magnitude.

It varies between intervals when it displays regular changes with a 37-day periodicity and times when it undergoes slow irregular variability.

P.K. Observation on the biting activity and flight periodicity of Culex pjpjonafaUgans in an urban area. WHOA/BC 75, 544. # Menon.P.K.B. and Rajagopaian.

The revealed similarities in the periodicity were strong supporting evidence for a case of massive HGT between the bacteria and the archaea kingdoms.

Because the wavelength of the laser cannot be varied over a large range in real time, the periodicity of the lattice is normally controlled by the relative angle between the laser beams. However, it is difficult to keep the lattice stable while changing the relative angles, since the interference is sensitive to the relative phase between the laser beams. Continuous control of the periodicity of a one- dimensional optical lattice while maintaining trapped atoms in-situ was first demonstrated in 2005 using a single-axis servo-controlled galvanometer. This "accordion lattice" was able to vary the lattice periodicity from 1.30 to 9.3 μm.

At the time of discovery in 2001, 47 Ursae Majoris was already known to host one extrasolar planet, designated 47 Ursae Majoris b. Further measurements of the radial velocity revealed another periodicity in the data unaccounted for by the first planet. This periodicity could be explained by assuming that a second planet, designated 47 Ursae Majoris c, existed in the system with an orbital period close to 7 years. Observations of the photosphere of 47 Ursae Majoris suggested that the periodicity could not be explained by stellar activity, making the planet interpretation more likely. The planet was announced in 2002.

In the case of a periodic function F with period λ, that is, F(x + λ − vt) = F(x − vt), the periodicity of F in space means that a snapshot of the wave at a given time t finds the wave varying periodically in space with period λ (the wavelength of the wave). In a similar fashion, this periodicity of F implies a periodicity in time as well: F(x − v(t + T)) = F(x − vt) provided vT = λ, so an observation of the wave at a fixed location x finds the wave undulating periodically in time with period T = λ/v.

The real case is significantly more complicated, exhibiting a periodicity of 8 rather than 2, and there is a 2-parameter family of Clifford algebras.

More recently, a different method of real-time control of the lattice periodicity was demonstrated, in which the center fringe moved less than 2.7 μm while the lattice periodicity was changed from 0.96 to 11.2 μm. Keeping atoms (or other particles) trapped while changing the lattice periodicity remains to be tested more thoroughly experimentally. Such accordion lattices are useful for controlling ultracold atoms in optical lattices, where small spacing is essential for quantum tunneling, and large spacing enables single- site manipulation and spatially resolved detection. Site-resolved detection of the occupancy of lattice sites of both bosons and fermions within a high tunneling regime is regularly performed in quantum gas microscopes.

This periodicity suggests that the hypothalamus, which is responsive to day length and photoperiod for regulating circadian and seasonal rhythms, has a role in its triggering.

The periodicity of renewal of accreditation follows the same three, five, or seven year cycle as that determined during risk analysis at renewal of institutional licensure.

Clemens Alexander Winkler (December 26, 1838 - October 8, 1904) was a German chemist who discovered the element germanium in 1886, solidifying Dmitri Mendeleev's theory of periodicity.

Concerning chromatic polarization, the wave theory explained the periodicity far better than the corpuscular theory, but had nothing to say about the role of polarization; and its explanation of the periodicity was largely ignored.Frankel, 1976, p. 155. And Arago had founded the study of chromatic polarization, only to lose the lead, controversially, to Biot. Such were the circumstances in which Arago first heard of Fresnel's interest in optics.

At high sounds levels, nerve fibers whose characteristic frequencies do not exactly match the stimulus still respond, because of the motion induced in larger areas of the basilar membrane by loud sounds. Temporal theory can help explain how we maintain this discrimination. Even when a larger group of nerve fibers are all firing, there is a periodicity to this firing, which corresponds to the periodicity of the stimulus.

The collagen fibrils are made of a mixture of type I and type V collagens. These molecules are tilted by about 15 degrees to the fibril axis, and because of this, the axial periodicity of the fibrils is reduced to 65 nm (in tendons, the periodicity is 67 nm). The diameter of the fibrils is remarkably uniform and varies from species to species. In humans, it is about 31 nm.

These are red giants or supergiants with little or no detectable periodicity. Some are poorly studied semiregular variables, often with multiple periods, but others may simply be chaotic.

G.D. and Mani.T.R. Observations on the biting activity and flight periodicity of Culex pipiens fatigans in an urban area, Faridabad. J. Com. Pis. 9 (1) : 22-23, 1977.

The many different forms of periodic table have prompted the question of whether there is an optimal or definitive form of periodic table. The answer to this question is thought to depend on whether the chemical periodicity seen to occur among the elements has an underlying truth, effectively hard-wired into the universe, or if any such periodicity is instead the product of subjective human interpretation, contingent upon the circumstances, beliefs and predilections of human observers. An objective basis for chemical periodicity would settle the questions about the location of hydrogen and helium, and the composition of group 3. Such an underlying truth, if it exists, is thought to have not yet been discovered.

Both the elliptic functions of Abel and of Jacobi can be derived from a more general formulation which was later given by Karl Weierstrass based on their double periodicity.

Recurrence period density entropy (RPDE) is a method, in the fields of dynamical systems, stochastic processes, and time series analysis, for determining the periodicity, or repetitiveness of a signal.

Lightcurve observations of Askania at the Menke Observatory in July 2006, show a well-defined periodicity of hours, during which time the brightness of the body varies by magnitude ().

If the hosts sleep by day and are awake at night, their periodicity is reversed. In the South Pacific, where W. bancrofti shows diurnal periodicity, it is known as periodic. The microfilariae are transferred into a vector, which are most commonly mosquito species of the genera Culex, Anopheles, Mansonia, and Aedes. Inside the mosquito, the microfilariae mature into motile larvae called juveniles; these migrate to the labium after a period around 10 days.

Pulsatile insulin secretion from individual beta cells is driven by oscillation of the calcium concentration in the cells. In beta cells lacking contact, the periodicity of these oscillations is rather variable (2-10 min). However, within an islet of Langerhans the oscillations become synchronized by electrical coupling between closely located beta cells that are connected by gap junctions, and the periodicity is more uniform (3-6 min). Coordination of pulsatile insulin release.

First, every state should adopt a periodic visit (periodicity) schedule that conforms to the model of the American Academy of Pediatrics. The visit content should conform to the Bright Futures guidelines. These professional guidelines are based on the best available evidence regarding what works for children in pediatric care and what can be achieved through well-child visits.Johnson K, Kaye N, Cullen A, and May J. Improving EPSDT Periodicity Schedules to Promote Healthy Development.

The companion has been identified from a high excitation component in the spectrum and from radial velocity variations, but the orbit is unknown. U Lacertae is a variable star classified as a semiregular variable. The periodicity is uncertain but a main period of 150 days and a long secondary period of 550 – 690 days have been suggested. A study of Hipparcos satellite photometry found an amplitude of 0.77 magnitudes and found no periodicity.

The hologram is made with a modified material that interacts with certain molecules generating a change in the fringe periodicity or refractive index, therefore, the color of the holographic reflection.

American Academy of Pediatrics. Recommendations for Preventive Pediatric Health Care. A separate children’s dental periodicity schedule is also required. One has been developed by the American Academy of Pediatric Dentistry.

707 Steina is a minor planet orbiting the Sun. The light curve of 707 Steina shows a periodicity of , during which time the brightness of the object varies by in magnitude.

608 Adolfine is a minor planet orbiting the Sun. The light curve of 608 Adolfine shows a periodicity of , during which time the brightness of the object varies by in magnitude.

Diurnal periodicity of activities in the plains killifish, Fundulus zebrinus kansae. Proc Okla Acad Sci 51 3-7. Molecular and genetic studies supported the separation of the species.Kreiser, B. R. (2001).

When the periodicity of the magnetic order coincides with the periodicity of crystallographic order, the magnetic phase is said to be commensurate, and can be well-described by a magnetic space group. However, when this is not the case, the order does not correspond to any magnetic space group. These phases can instead by described by magnetic superspace groups, which describe incommensurate order. This is the same formalism often used to describe the ordering of some quasicrystals.

In other words, they maintain circadian periodicity over a range of physiological temperatures. Many organisms live at a broad range of temperatures, and differences in thermal energy will affect the kinetics of all molecular processes in their . In order to keep track of time, the organism's circadian clock must maintain roughly a 24-hour periodicity despite the changing kinetics, a property known as temperature compensation. The Q10 Temperature Coefficient is a measure of this compensating effect.

Functional periodicity is a term that emerged around the late 19th century around the belief, later to be found invalid, that women suffered from physical and mental impairment during their menstrual cycle. Men held a higher status and were regarded as superior to women at this period in time. Many prominent male psychologists promoted the idea of functional periodicity. Women were not seen as being fit for certain types of work, responsibilities, and roles because of this idea.

Identifying genes in a DNA sequence is harder than just finding what segments are coding and near impossible to identify by visually inspecting spectrograms. Genes are made up of both coding and non- coding regions, called introns and exons. Thus, the transition between coding and non-coding regions must be examined and analyzed properly to identify genes. Computing the "level" of 3-periodicity over different (possibly overlapping) windows of the sequence generates a plot of 3-periodicity over time.

Lõhmus, A. (2011). Three-year periodicity in historical raptor-persecution data: an indication of vole cycles? Estonian Journal of Ecology, 60(2), 155.Voříšek, P., Reif, J., Šťastný, K., & Bejček, V. (2008).

Milankovitch pacing seems to best explain glaciation events with periodicity of 100,000, 40,000, and 20,000 years. Such a pattern seems to fit the information on climate change found in oxygen isotope cores.

He found a proof of several generalizations using elliptic operators; this new proof used an idea that he used to give a particularly short and easy proof of Bott's original periodicity theorem.

The presence of the 12-periodicity in the circle of fifths yields applications of elementary group theory in musical set theory. Transformational theory models musical transformations as elements of a mathematical group.

Invertebrate Reproduction and Development. 17(1):1–7. and periodicity of spawning is regulated by lunar cycles, specifically following a full moon.Morgan, A. 2009. Spawning of the Temperate sea cucumber, Australostichopus mollis(Levin).

In binary chirp modulation, binary data is transmitted by mapping the bits into chirps of opposite chirp rates. For instance, over one bit period "1" is assigned a chirp with positive rate a and "0" a chirp with negative rate −a. Chirps have been heavily used in radar applications and as a result advanced sources for transmission and matched filters for reception of linear chirps are available. (a) In image processing, direct periodicity seldom occurs, but, rather, periodicity-in-perspective is encountered.

Quasiperiodicity is the property of a system that displays irregular periodicity. Periodic behavior is defined as recurring at regular intervals, such as "every 24 hours".Periodicity – Definition and More from the Free Merriam-Webster Dictionary Quasiperiodic behavior is a pattern of recurrence with a component of unpredictability that does not lend itself to precise measurement.Quasiperiodic – Definition and More from the Free Merriam-Webster Dictionary It is different from the mathematical concept of an almost periodic function, which has increasing regularity over multiple periods.

Thus radio emission from RRATs is typically only detectable for less than one second per day. The sporadic emission from RRATs means that they are usually not detectable in standard periodicity searches which use Fourier techniques. Nevertheless, underlying periodicity in RRATs can be determined by finding the greatest common denominator of the intervals between pulses. This yields the maximum period but once many pulse arrival times have been determined the periods which are shorter (by an integer factor) can be deemed statistically unlikely.

ATP signalling has also been proposed as a method of coordination between beta cells. Pulsatile insulin secretion from individual beta cells is driven by oscillation of the calcium concentration in the cells. In beta cells lacking contact, the periodicity of these oscillations is rather variable (2-10 min). However, within an islet of Langerhans, the oscillations become synchronized by electrical coupling between closely located beta cells that are connected by gap junctions, and the periodicity is more uniform (3-6 min).

Gliese 176 b is a super-Earth exoplanet approximately 31 light years away in the constellation of Taurus. This planet orbits very close to its parent red dwarf star Gliese 176 (also called "HD 285968"). The initial announcement confused the planetary periodicity with the stellar periodicity of 40 days, thus giving a 10.24 day period for a 25 Earth-mass planet. Subsequent readings filtered out the star's rotation, giving a more accurate reading of the planet's orbit and minimum mass.

An 8.77-day periodicity - corresponding to the planet announced by the HARPS team - was detected to intermediate significance, though it was not deemed significant enough to claim a planetary cause with their data alone.

Ecology 79 1657–1668. Flowering is synchronized among plants in a given area, with widespread, picturesque blooms occurring periodically.Taylor, O. R. and D. W. Inouye. (1985). Synchrony and periodicity of flowering in Frasera speciosa (Gentianaceae).

The nearly free electron model rewrites the Schrödinger equation for the case of a periodic potential. The solutions in this case are known as Bloch states. Since Bloch's theorem applies only to periodic potentials, and since unceasing random movements of atoms in a crystal disrupt periodicity, this use of Bloch's theorem is only an approximation, but it has proven to be a tremendously valuable approximation, without which most solid-state physics analysis would be intractable. Deviations from periodicity are treated by quantum mechanical perturbation theory.

Analogous identities are Euler's four-square related to quaternions, and Degen's eight-square derived from the octonions which has connections to Bott periodicity. There is also Pfister's sixteen-square identity, though it is no longer bilinear.

Leta Hollingworth decided to use tests that had been used previously by psychologists to complete her study. She decided to use a familiar tapping test and steadiness test to assess motor ability.Green, C.D. (2000). Functional periodicity.

The J-homomorphism is a homomorphism from the homotopy groups of orthogonal groups to stable homotopy groups of spheres, which causes the period 8 Bott periodicity to be visible in the stable homotopy groups of spheres.

Spawning periodicity is 4–5 years in females and 3–4 years in males. Water temperature affects the onset of maturity of females. Females spawn a year earlier during warm years than they would during cold years.

The low periodicity half- elliptical springs were zinc interleaved with oilite self-lubrication discs at the end of the main leaves. Oil could be fed between the leaves by grease gun through a nipple under each spring.

Periodic short-interval diffuse discharges are a type of EEG abnormality with periodicity less than 4.0 seconds. They can consist of sharp waves or spikes, spike and wave, polyspikes or triphasics with background attenuation in between transients.

According to Marcy & Benitz (1989) detected a possible periodicity of 416 days, inferring possible presence of a massive planetary object with minimum mass of 11 times that of Jupiter. So far the planet has not been confirmed.

Gratings with such small periodicity are called subwavelength gratings and exhibit special optical properties. Made on an isotropic material the subwavelength gratings give rise to form birefringence, in which the material behaves as if it were birefringent.

The strictest form of order in a solid is lattice periodicity: a certain pattern (the arrangement of atoms in a unit cell) is repeated again and again to form a translationally invariant tiling of space. This is the defining property of a crystal. Possible symmetries have been classified in 14 Bravais lattices and 230 space groups. Lattice periodicity implies long-range order: if only one unit cell is known, then by virtue of the translational symmetry it is possible to accurately predict all atomic positions at arbitrary distances.

William G. Tifft was the first to investigate possible redshift quantization, referring to it as "redshift-magnitude banding correlation". In 1973, he wrote: :"Using more than 200 redshifts in Coma, Perseus, and A2199, the presence of a distinct band-related periodicity in redshifts is indicated. Finally, a new sample of accurate redshifts of bright Coma galaxies on a single band is presented, which shows a strong redshift periodicity of 220 km s−1. An upper limit of 20 km s−1 is placed on the internal Doppler redshift component of motion in the Coma cluster".

DeKimpe et al. (1961). From those tests the role of periodicity becomes convincingly clear. DeKimpe et al. (1961) had used daily additions of alumina (as ) and silica (in the form of ethyl silicate) during at least two months. In addition, adjustments of the pH took place every day by way of adding either hydrochloric acid or sodium hydroxide. Such daily additions of Si and Al to the solution in combination with the daily titrations with hydrochloric acid or sodium hydroxide during at least 60 days will have introduced the necessary element of periodicity.

Plasmodium coatneyi was first discovered in 1961 by Dr. Don Eyles in the Malaysian state of Selangor. Plasmodium coatneyi was isolated from an Anopheles hackeri before being found in its primate host species. This was the first occurrence of acquiring a new form of malaria through its vector instead of an infected host specimen. The sample was first thought to be Plasmodium knowlesi due to the morphological similarities of the two species, but was later identified as separate due to having a tertiary periodicity compared to P. knowlesi’s quartan periodicity.

Mendeleev asserted that there was a fixed periodicity of eight, and expected a mathematical correlation between atomic number and chemical properties; Pauli demonstrated that this was not the case. Instead, the Pauli exclusion principle was developed. This states that no electrons can coexist in the same quantum state, and showed, in conjunction with empirical observations, the existence of four quantum numbers and the consequence on the order of shell filling. This determines the order in which electron shells are filled and explains the periodicity of the periodic table.

By definition, metamaterials are realized as lattices whose periodicity is assumed to be much smaller than the wavelength. However, it is important that, though small, the periodicity is not negligible with respect to the wavelength. For this reason, if one formally introduces constitutive parameters for such regime, they will not be measurable response functions, and it will not be possible to use them for a sample of other dimensions or for a sample excited in another way. In other words, such formally introduced material parameters cannot satisfy the conditions of locality.

The sum of transient factors acting at the Earth's surface is cyclical: climate, ocean currents and other movements, wind currents, temperature, etc. The waveform response comes from the underlying cyclical motions of the planet, which eventually drag all the transients into harmony with them. The repeated glaciations of the Pleistocene were caused by the same factors. The Mid-Pleistocene Transition, approximately one million years ago, saw a change from low-amplitude glacial cycles with a dominant periodicity of 41,000 years to asymmetric high- amplitude cycles dominated by a periodicity of 100,000 years.

It addresses the fact that the network of biomolecules in cells and tissues follows topological rules enabling coordinated actions. For example, the cell surface toponome provides the spatial protein interaction code for the execution of a cell movement, a "code of conduct". This is intrinsically dependent on the specific spatial arrangement of similar and dissimilar compositions of supermolecules (compositional periodicity) with a specific spatial order along a cell surface membrane. This spatial order is periodically repeated when the cell tries to enter the exploratory state from the spherical state (spatial periodicity).

For resonance to occur, it is necessary to have also periodicity in the excitation force. The most tempting candidate of the periodicity in the wind force was assumed to be the so-called vortex shedding. This is because bluff bodies (non-streamlined bodies), like bridge decks, in a fluid stream shed wakes, whose characteristics depend on the size and shape of the body and the properties of the fluid. These wakes are accompanied by alternating low-pressure vortices on the downwind side of the body (the so-called Von Kármán vortex street).

This property has been dissected, tested and derived in a chronology of papers from different universities. The initial discovery was made in 1980 by Trifonov and Sussman who observed periodicity in DNA sequences by applying the autocorrelation function to chromatin DNA. Silverman and Linsker defined the Fourier transform of a sequence of bases, described how to "fourier analyze" it and proposed sample applications of this technique. Tsonis, Elsner and Tsonis did Fourier analysis of coding, non- coding and random sequences and proposed a reason for the 3-periodicity property found in coding sequences.

Since periodicity and twins were ruled out, Blech, unaware of the two- dimensional tiling work, was looking for another possibility: a completely new structure containing cells connected to each other by defined angles and distances but without translational periodicity. Blech decided to use a computer simulation to calculate the diffraction intensity from a cluster of such a material without long-range translational order but still not random. He termed this new structure multiple polyhedral. The idea of a new structure was the necessary paradigm shift to break the impasse.

If the elements were ordered based on increasing atomic mass, however, periodicity in chemical properties was exhibited. Exceptions to this periodicity were apparent, however, such as cobalt and nickel. At the University of Manchester in 1913 Henry Moseley discussed the new Bohr model of the atom with the visiting Bohr. The model accounted for the electromagnetic emission spectrum from the hydrogen atom, and Moseley and Bohr wondered if the electromagnetic emission spectra of heavier elements such as cobalt and nickel would follow their ordering by weight, or by their position in the periodic table.

In its absence, the many different forms of periodic table can be regarded as variations on the theme of chemical periodicity, each of which explores and emphasizes different aspects, properties, perspectives and relationships of and among the elements.

Evolution follows distinct paths in accord with certain immutable laws, aspects of which are perceivable on the physical level. One such law is the law of periodicity and cyclicity; another is the law of karma or cause and effect.

Morse originally applied his theory to geodesics (critical points of the energy functional on paths). These techniques were used in Raoul Bott's proof of his periodicity theorem. The analogue of Morse theory for complex manifolds is Picard–Lefschetz theory.

The life cycle is typical of a species of the genus Plasmodium. It has a 72-hour (or quartan) periodicity. Salivary gland sporozoites appear in Anopheles dirus 13 days post feeding. The prepatent period in the vertebrate host is 8 days.

Vision services, at a minimum, include diagnosis and treatment for defects in vision and eyeglasses when appropriate. Vision services must be provided according to a distinct, separate periodicity schedule developed by the state and at other intervals as medically necessary.

Besides his career in economics, he performed experiments between 1952 and 1960 in the fields of gravitation, special relativity and electromagnetism, to investigate possible links between the fields. He reported three effects: # An unexpected anomalous effect in the angular velocity of the plane of oscillation of a paraconical pendulum, detected during two partial solar eclipses in 1954 and 1959. The claimed effect is now called the Allais effect. # Anomalous irregularities in the oscillation of the paraconical pendulum with respect to a sidereal diurnal periodicity of 23 hours 56 minutes and tidal periodicity of 24 hours 50 minutes.

Although Raup and Sepkoski could not identify the cause of their supposed periodicity, they suggested a possible non-terrestrial connection. The challenge to propose a mechanism was quickly addressed by several teams of astronomers. In 2010, Melott & Bambach re-examined the fossil data, including the now-improved dating, and using a second independent database in addition to that Raup & Sepkoski had used. They found evidence for a signal showing an excess extinction rate with a 27-million-year periodicity, now going back 500 million years, and at a much higher statistical significance than in the older work.

Photometry from the Hipparcos satellite mission showed that DU Crucis varies in brightness with an amplitude of 0.44 magnitudes. No periodicity could be detected in the variations and it was classified as a slow irregular variable of type Lc, indicating a supergiant.

Arnold Samuel Shapiro (1921, Boston, Massachusetts – 1962, Newton, Massachusetts) was an American mathematician known for his eversion of the sphere. He also was the author of an article on Clifford algebras and periodicity with Raoul Bott, later redone by Michael Atiyah and Bott.

It varies slightly in brightness, with a periodicity of 6.2 days and an amplitude change of 0.0096 in magnitude. On average it is radiating 387 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 4,013 K.

Traditionally, there used to be a weekly market, locally called hat. Apart from vegetables, such needs as pottery, wooden materials, iron materials, baskets, seeds etc. were available. With the passage of time the periodicity gradually increased till it became a daily market.

Marraro, C. & Nursall, J.. (2011). The reproductive periodicity and behaviour of Ophioblennius atlanticus (Pisces: Blenniidae) at Barbados. Canadian Journal of Zoology. 61. 317-325. 10.1139/z83-042. Ophioblennius trinitatis eggs are demersal and are attached to substrate using an adhesive pad or pedestal.

Food Habits and Feeding Periodicity in Two Sympatric Stonerollers Cyprinidae. vol. 113, no. 2. The largescale stoneroller's predators include large and smallmouth bass, the spotted bass, sager, and the walleye. It is a popular baitfish so anglers also catch them for fishing.

This register has the details of the periodical reports, their subjects, the periodicity and to whom they are to be sent. The special register will have details of important references marked as Special by Head of Office and to be dealt with separately.

Adults fly from July through August. Like most skippers, they are fairly strictly diurnal, though individuals are very rarely encountered during the night. (2001): Diel flight periodicity and the evolution of auditory defences in the Macrolepidoptera. Animal Behaviour 62(2): 349–368.

According to Marcy & Benitz (1989) detected a possible periodicity of 510 days, inferring possible presence of a massive planetary object with minimum mass of 12 times that of Jupiter in highly eccentric orbit (e=0.6). So far the planet has not been confirmed.

The life of such massive stars is very short. Despite its advanced evolutionary state, V419 Cephei is only 10 million years old. Billed as an irregular variable star of type LC, V419 Cephei's brightness varies between magnitudes 6.54 and 6.89 with no apparent periodicity.

Cho et al. were the first who determined that clustered genes have the same expression levels. They identified transcripts that show cell-cycle dependent periodicity. Of those genes 25% was located in close proximity to other genes which were transcript in the same cell cycle.

KY Cygni is a variable star with a large amplitude but no clear periodicity. At times, it varies rapidly, at others it is fairly constant for long periods. The photographic magnitude range is given as 13.5 - 15.5, while a visual range is 10.60 - 11.74.

Studies performed in the 1980s and early 1990s produced confirmatory results: #In 1989, Martin R. Croasdale reported finding a quantization of redshifts using a different sample of galaxies in increments of 72 km/s or Δz = (where Δz denotes shift in frequency expressed as a proportion of initial frequency). #In 1990, Bruce Guthrie and William Napier reported finding a "possible periodicity" of the same magnitude for a slightly larger data set limited to bright spiral galaxies and excluding other types. #In 1992, Guthrie and Napier proposed the observation of a different periodicity in increments of Δz = in a sample of 89 galaxies. #In 1992, Paal et al.

Time series and first delay plots provide the best support for the claims made, showing a fairly clear march from periodicity to irregularity as the feeding times were increased. The various phase trajectory plots and spectral analyses, on the other hand, do not match up well enough with the other graphs or with the overall theory to lead inexorably to a chaotic diagnosis. For example, the phase trajectories do not show a definite progression towards greater and greater complexity (and away from periodicity); the process seems quite muddied. Also, where Metcalf and Allen saw periods of two and six in their spectral plots, there is room for alternative interpretations.

They migrate between the deep and the peripheral, circulation exhibiting unique diurnal periodicity. During the day, they are present in the deep veins, and during the night, they migrate to the peripheral circulation. The cause of this periodicity remains unknown, but the advantages of the microfilariae being in the peripheral blood during these hours may ensure the vector, the nighttime mosquito, will have a higher chance of transmitting them elsewhere. Physiological changes also are associated with sleeping, such as lowered body temperature, oxygen tension, and adrenal activity, and an increased carbon dioxide tension, among other physical alterations, any of which could be the signals for the rhythmic behavior of microfilarial parasites.

12-step equal tuning, showing just intonation values on the left and the corresponding equal tuning values on the right Fokker periodicity blocks are a concept in tuning theory used to mathematically relate musical intervals in just intonation to those in equal tuning. They are named after Adriaan Daniël Fokker. These are included as the primary subset of what Erv Wilson refers to as constant structures, where "each interval occurs always subtended by the same number of steps". The basic idea of Fokker's periodicity blocks is to represent just ratios as points on a lattice, and to find vectors in the lattice which represent very small intervals, known as commas.

Just as the nucleotide composition of a DNA molecule can be represented by a sequence of letters, its structural features can be encoded in a numerical sequence. The structural features include interaction energies between neighbouring base pairs, the angle of twist that makes two bases of a pair non-coplanar, or DNA deformability induced by the proteins shaping the chromatin. The autocorrelation analysis of some of these numerical sequences show characteristic periodicities in complete genomes. In fact, after detecting archaea-like regions in the thermophilic bacteria Thermotoga maritima, periodicity spectra of these regions were compared to the periodicity spectra of the homologous regions in the archaea Pyrococcus horikoshii.

In work related to the Langlands correspondence, the mean-periodicity of certain (functions related to) zeta functions associated to an arithmetic scheme have been suggested to correspond to automorphicity of the related L-function. There is a certain class of mean-periodic functions arising from number theory.

The peak-phase includes oscillation of MOF with periodicity of approximately 5...10 minutes. The propagation range for Es single-hop is typically 1000 to 2000 km, but with multi-hop, double range is observed. The signals are very strong but also with slow deep fading.

They are also Lewis acids, because they accept electron pairs from some Lewis bases, most notably base anhydrides. The oxides of period three elements demonstrate periodicity with respect to acidity. As one moves across the period, the oxides become more acidic. Sodium and magnesium oxides are alkaline.

V923 Aquilae is a Be star in the equatorial constellation of Aquila. It is a binary star with a low mass secondary star orbiting at a separation of around 250 times the radius of the Sun. The primary varies with both short term and long term periodicity.

His doctoral work of 1896 was on the variable η Aquilae. He worked with his father initially examining sunspot periodicity and weather correlations. He then travelled around the world following eclipses from 1896 to 1932. He was involved in the establishment of the International Meteorological Committee.

Cahiers Octave Mirbeau is a French literary journal founded in 1994 by French scholar and Octave Mirbeau specialist Pierre Michel. The journal is based in Angers, France. Its periodicity is annual. Between May 1994 and March 2016, 23 installments were released, totaling more than 8 300 pages.

Collectanea Mathematica is a mathematical journal of the Institute of Mathematics of the University of Barcelona (IMUB), published by Springer since 2011, with a periodicity of three issues per year. It publishes original research papers of high quality in all fields of pure and applied mathematics.

Other tracks offer bleak insight into current social issues including chronic unemployment, the plight of migrant women, foreign domination of Australian business and government, and the apathy of 'middle Australia'. "Women in Change" features the last 4 stanzas from Lesbia Harford's poem "Periodicity", commenting on a woman's menstrual cycle.

Raoul Bott (September 24, 1923 – December 20, 2005) was a Hungarian-American mathematician known for numerous basic contributions to geometry in its broad sense. He is best known for his Bott periodicity theorem, the Morse–Bott functions which he used in this context, and the Borel–Bott–Weil theorem.

This breeding activity contrasts with the closely related Bermuda fireworm (Odontosyllis enopla) which is largely non-seasonal in its breeding behaviour but very specific in its lunar periodicity and timing, rising to the surface to spawn 55 minutes after sunset, on a night just after the full moon.

Low frequency sounds evoke the strongest pitches, suggesting that pitch is based on the temporal components of the sound. Historically, there have been many models of pitch perception. (Terhardt, 1974; Goldstein, 1973; Wightman, 1973). Many consisted of a peripheral spectral-analysis stage and a central periodicity-analysis stage.

Dodin proposed a method for analyzing the periodicity of DNA sequences based on the correlation function of the symbolic sequence. Tiwari, Ramachandran, Bhattacharya and Ramaswamy examined the signal-to-noise ratio of the period-3 peak within a sliding window over a sequence to identify likely coding regions.

941 p. Additionally, the spawning and settlement of Ophioblennius trinitatis is seasonal and follows lunar periodicity. Male Ophioblennius trinitatis have nests within their territory for spawning, and when the full moon approaches, females seek male nests for mating. After spawning, the males guard the nest to keep eggs safe.

It has been found that the periodicity in the photometric variability of HD 166 is coincident with the rotation period. This leads to its classification as a BY Draconis variable, where brightness variations are caused by the presence of large starspots on the surface and by chromospheric activity.

Other explanations, of lesser likelihood, to the observed sinusoidal periodicity include a hot spot on the inner part of the black hole's accretion disk and the possibility of a warped accretion disk which partially eclipses in the orbit around a single SMBH. However, it also remains possible that the periodic behavior in PKS 1302-102 is indeed just a random occurrence in the light curve of an ordinary quasar, as spurious nearly- periodic variations can occur over limited time periods as part of stochastic quasar variability. Further observations of the quasar could either promote true periodicity or rule out a binary interpretation, especially if the measured light curve randomly diverges from the sinusoidal model.

Treating pitches separated by a comma as equivalent "folds" the lattice, effectively reducing its dimension by one; mathematically, this corresponds to finding the quotient group of the original lattice by the sublattice generated by the commas. For an n-dimensional lattice, identifying n linearly independent commas reduces the dimension of the lattice to zero, meaning that the number of pitches in the lattice is finite; mathematically, its quotient is a finite abelian group. This zero-dimensional set of pitches is a periodicity block. Frequently, it forms a cyclic group, in which case identifying the m pitches of the periodicity block with m-equal tuning gives equal tuning approximations of the just ratios that defined the original lattice.

An example of reasoning using functional periodicity is a quote by Henry Maudsley in 1874. He further states: ‘"This is a matter of physiology, not a matter of sentiment… not a question of two bodies and minds that are in equal physical condition, but if one body and mind capable of sustained and regular hard labor, and of another body and mind which for one quarter of each month, during the best years of life, is more or less sick and unfit for hard work." This quote exemplifies the sexist beliefs expressed during this time period. Because of these opinions and beliefs, the idea of functional periodicity became more relevant in American society.

When looking at the first row of entries in a Laver table, it can be seen that the entries repeat with a certain periodicity m. This periodicity is always a power of 2; the first few periodicities are 1, 1, 2, 4, 4, 8, 8, 8, 8, 16, 16, ... . The sequence is increasing, and it was proved in 1995 by Richard Laver that under the assumption that there exists a rank-into-rank (a large cardinal), it actually increases without bound.. Nevertheless, it grows extremely slowly; Randall Dougherty showed that the first n for which the table entries' period can possibly be 32 is A(9,A(8,A(8,255))), where A denotes the Ackermann function..

The elliptic functions thus have a double periodicity. Equivalently one can say that they have two complex periods . Their zeros and poles will thus form a regular, two-dimensional lattice. Corresponding properties of the lemniscatic elliptic functions had also been established by Gauss, but not published before after his death.

For materials to settle in stratified layers the defining quality is periodicity. There must be repeated depositional events with changes in precipitation of materials over time. The thickness of graded beds ranges from 1 millimeter to multiple meters. There is no set time limit in which the layers are formed.

Spectrum: KSp Coefficient ring: The coefficient groups πi(KSp) have period 8 in i, given by the sequence Z, 0, 0, 0,Z, Z2, Z2,0, repeated. KSp0(X) is the ring of stable equivalence classes of quaternionic vector bundles over X. Bott periodicity implies that the K-groups have period 8.

1967; first published 1939. My Life London: Spearman. in contrast to Krafft-Ebing's interpretations. With such titles as Analysis of the Sexual Impulse, Love and Pain, The Sexual Impulse in Women and The Evolution of Modesty, The Phenomena of Sexual Periodicity, Auto-Erotism, he described the basics of the condition.

Some of these factors aren't yet well understood, for instance the ice ages occur on 100,000 year cycles, and it's not completely understood why the various effects with this periodicity have such a strong effect on glaciation (see the 100,000-year problem). Artist's rendition of geomagnetic storm. Sizes are not to scale.

In eastern Canada, local outbreaks of N. abietis can last anywhere from 3 years to 5 years and have been shown to have a periodicity of about 10 years.G. Moreau (2006). Past and present outbreaks of the balsam fir sawfly in western Newfoundland: An analytical review. Forest Ecology and Management 221: 215-219.

Rampino has published two books, a text for a course on Astrobiology (Jastrow and Rampino, 2008) and a popular portrayal of the effects of catastrophic events on Earth history and the history of life (Rampino, 2017). He was co-editor of the conference volume “Climate: History, Periodicity and Predictability” published in 1987.

Little is known about the components of LL Andromedae because it's a faint object; one of the two components is likely an accreting white dwarf like in all dwarf novae. A brown dwarf donor has been proposed, but the short periodicity of superhumps hints instead at the presence of a massive companion.

During follow-up observations, a few of these were found to be pulsars that had been missed in periodicity searches, but 11 sources were characterized by single dispersed pulses, with irregular intervals between pulses lasting from minutes to hours. over 100 have been reported, with dispersion measures up to 764 cm−3pc.

He also studied volcanism and seismic phenomena on Earth, sometimes at the risk of his life. He was a pioneer in using the aneroid barometer for measuring altitude. He published a work on the physical geography of Greece. Other interests were the physical nature of comets and the brightness and periodicity of stars.

It consisted of three panels with of mercury. The original beacon installed had a constant five rotations, but was replaced by an incandescent gas lamp. Its rotation was maintained with a clockwork system, allowing it to have a periodicity of 15 seconds, and range of . In 1914, a signal horn was installed.

This study led Fesenko to introduce a new mean-periodicity correspondence between the arithmetic zeta functions and mean-periodic elements of the space of smooth functions on the real line of not more than exponential growth at infinity. This correspondence can be viewed as a weaker version of the Langlands correspondence, where L-functions and replaced by zeta functions and automorphicity is replaced by mean- periodicity. This work was followed by a joint work with Suzuki and Ricotta. The second development is an application to the generalized Riemann hypothesis, which in this higher theory is reduced to a certain positivity property of small derivatives of the boundary function and to the properties of the spectrum of the Laplace transform of the boundary function.

For the theory associated to the infinite unitary group, U, the space BU is the classifying space for stable complex vector bundles (a Grassmannian in infinite dimensions). One formulation of Bott periodicity describes the twofold loop space, Ω2BU of BU. Here, Ω is the loop space functor, right adjoint to suspension and left adjoint to the classifying space construction. Bott periodicity states that this double loop space is essentially BU again; more precisely, :\Omega^2BU\simeq \Z\times BU is essentially (that is, homotopy equivalent to) the union of a countable number of copies of BU. An equivalent formulation is :\Omega^2U\simeq U . Either of these has the immediate effect of showing why (complex) topological K-theory is a 2-fold periodic theory.

Previous Great White Spots were observed in 1876, 1903, 1933 and 1960, with the 1933 storm being the most famous. If the periodicity is maintained, another storm will occur in about 2020. The winds on Saturn are the second fastest among the Solar System's planets, after Neptune's. Voyager data indicate peak easterly winds of .

BO Car is a red supergiant of spectral type M4Ib with an effective temperature of , a radius of . Its bolometric luminosity is . Mass-loss is on the order of per year. Billed as an irregular variable like TZ Cassiopeiae or V528 Carinae; its apparent brightness fluctuates between magnitude +7.18 and +8.50 without clear periodicity.

The system includes 15 bus lines numbered 1 to 16 (number 13 is empty). Connex Příbram uses buses Karosa (B731, B732, B932 or B952) and SOR (B 9.5 and BN 12). Basic line no. 2 has regular 10-minutes interval (5 minutes in rush periods), other lines periodicity varies down to several buses per day.

Studies of living and extinct human and non-human primates. Cambridge: Cambridge University Press, pp. 269-305. The regulatory 'clock', in this case, is the sun's position in relation to the tilt of the earth. In nocturnal or partly nocturnal primates—for example, owl monkeys— the periodicity of the moon may also come into play.

The mean visual magnitude is 4.87 and its brightness changes at most by less than a tenth of a magnitude. A simplistic fitting of Hipparcos data suggests a periodicity of 1.6 days. V1073 Scorpii is a runaway star, moving at more than 37 km/s relative to its neighbourhood. No bow shock has been detected.

The areas where SSA can be applied are very broad: climatology, marine science, geophysics, engineering, image processing, medicine, econometrics among them. Hence different modifications of SSA have been proposed and different methodologies of SSA are used in practical applications such as trend extraction, periodicity detection, seasonal adjustment, smoothing, noise reduction (Golyandina, et al, 2001).

A slow irregular variable (ascribed the GCVS types L, LB and LC) is a variable star that exhibit no or very poorly defined periodicity in their slowly changing light emissions. These stars have often been little-studied, and once more is learnt about them, they are reclassified into other categories such as semiregular variables.

The stimulus modality for hearing is sound. Sound is created through changes in the pressure of the air. As an object vibrates, it compresses the surrounding molecules of air as it moves towards a given point and expands the molecules as it moves away from the point. Periodicity in sound waves is measured in hertz.

To learn about when algebras (in the technical sense) have a division operation, refer to the page on division algebras. In particular Bott periodicity can be used to show that any real normed division algebra must be isomorphic to either the real numbers R, the complex numbers C, the quaternions H, or the octonions O.

710 Gertrud is a Themistian asteroid, which means it is a member of the Themis family of asteroids. It was discovered by Austrian astronomer Johann Palisa on 28 February 1911 from Vienna. The light curve of 710 Gertrud shows a periodicity of , during which time the brightness of the object varies by in magnitude.

In the following it will be assumed that the Zak transform is as given in Definition 2. 1\. Linearity Let a and b be any real or complex numbers. Then :Z[af+bg](t,w)=aZ[f](t,w)+bZ[g](t,w) 2\. Periodicity :Z[f](t, w+1) = Z[f](t,w) 3\.

His three deputies are PhD Sergei E. Tshernyshev (ISEA SB RAS), PhD Kirill G. Mikhailov (the MSU Zoomuseum, Moscow) and ScD Andrei A. Legalov (ISEA SB RAS). There are competent entomologists from recognised research establishments and universities of Russia, Belarus, Ukraine and the United Kingdom in the Journal editorial board. The Journal periodicity is six issues per year.

Voice pitch or musical pitch information, conveyed primarily via weak periodicity cues in the ENVp, results in a pitch sensation that is not salient enough to support music perception, talker sex identification, lexical tones, or prosodic cues. Listeners with cochlear implants are susceptible to interference in the modulation domain which likely contributes to difficulties listening in noise.

The image has the low signal-to-noise ratio due to the high concentration of NaCl. (C) Cryo- transmission electron micrograph of a focused ion beam-thinned cell in 3 M NaCl plus 81 mM MgSO4. The periodicity of the gas vesicle is clearly discerned. (A) Adapted from Pfeifer (2015), (B, C) from Bollschweiler et al.

State i is positive recurrent if M_i is finite and null recurrent otherwise. Periodicity, transience, recurrence and positive and null recurrence are class properties—that is, if one state has the property then all states in its communicating class have the property. A state i is called absorbing if there are no outgoing transitions from the state.

A periodic function is a function that repeats its values at regular intervals, for example, the trigonometric functions, which repeat at intervals of 2π radians. Periodic functions are used throughout science to describe oscillations, waves, and other phenomena that exhibit periodicity. Any function that is not periodic is called aperiodic. An illustration of a periodic function with period P.

Photometric and spectral variability of GR Andromedae is typical of a star with a strong and variable magnetic field. This way, the 518.2 days periodicity can be identified as the rotation period of the star. It's among the slowest rotators in the category of magnetic chemically peculiar stars, with a calculated equatorial rotation rate of only .

Melanie Klein, 'Review of 'Women's Periodicity ', 1933. In 1930 Chadwick befriended the poet H.D., the novelist Bryher and the filmmaker Kenneth Macpherson. H.D., Bryher and MacPherson collaborated in film production as the Pool Group, and Chadwick wrote for their magazine, Close Up, in 1931. Bryher paid for both Kenneth Macpherson and H.D. to go into analysis with Chadwick.

Aphthous ulcers typically begin as erythematous macules (reddened, flat area of mucosa) which develop into ulcers that are covered with a yellow-grey fibrinous membrane that can be scraped away. A reddish "halo" surrounds the ulcer. The size, number, location, healing time, and periodicity between episodes of ulcer formation are all dependent upon the subtype of aphthous stomatitis.

Yambo uses a plane waves basis set to represent the electronic (single-particle) wavefunctions. Core electrons are described with norm-conserving pseudopotentials. The choice of a plane-wave basis set enforces the periodicity of the systems. Isolated systems, and systems that are periodic in only one or two directions can be treated by using a supercell approach.

The regulatory "clock", in this case, is the sun's position in relation to the tilt of the earth. In nocturnal or partly nocturnal primates—for example, owl monkeys—the periodicity of the moon may also come into play.Nash, L. T. 2007. Moonlight and behavior in nocturnal and cathemeral primates, especially Lepilemur leucopus: Illuminating possible anti-predator efforts.

If a newspaper is defined by the functional criteria of publicity, seriality, periodicity, and currency or actuality (that is, as a single current-affairs series published regularly at intervals short enough for readers to keep abreast of incoming news) then Relation was the first European newspaper.Fischer, H.-D. Die Zeitung als Forschungsproblem. In Deutsche Zeitungen des 17.

Along each tektin rod, cysteine residues occur with a periodicity of ~8 nm, coincident with the axial repeat of tubulin dimers in microtubules. It is proposed that the assembly of tektin heteropolymers produces filaments with repeats of 8, 16, 24, 32, 40, 48 and 96 nm, generating the basis for the complex spatial arrangements of axonemal components.

Criterion was the first philosophy journal in Catalan. It was founded by the Capuchin Miquel d'Esplugues, who was its first director also. Its periodicity was quarterly at first, between 1925 and 1936.Article in the Great Catalan Encyclopedia It appeared again after the Spanish Civil War, now as a collection of philosophical and religious matters, en 1959.

Bob's team at Macquarie Island and Mawson Station provided new information about the nature and source of cosmic rays. Specifically, his team reaffirmed that the rays primary source was from 'storms' on the Sun, and suggested that a small proportion of these rays had sidereal rather than solar periodicity. This important finding implied a Galactic or extra-galactic origin.

Charter introduced a periodicity of Local and Bishops' Councils at least once every two years. Was expanded structure of the Holy Synod: the number of its permanent members increased to five. Diocesan congregation was restored. The ruling bishop, with the assistance of the meeting (of an equal number of clergy and laity) directs the church life in the diocese.

The event took place mainly in the Cultural Center of UFMG, besides having exhibitions in libraries over the city. France was the first honored country, counting on special exhibitions, including one in honor of the artist François Boucq. The guest of honor of this edition was the cartoonist Angeli. From then on, the event maintained the biennial periodicity.

He gave the Society Tutorial at the spring meeting in 1996 entitled, "Pitch, Periodicity and the Brain." He served as vice president of the Society (1998–1999) and as president (2001–2002). As president, he worked to enhance the Society's connections with allied organizations such as the Institute for Noise Control Engineering, and to expand the Society's international presence.

The first planet was discovered in 2001 from the Lick and Keck observatories using precision measurements of the star's radial velocity variations. The periodicity in this variation allowed astronomers to extract information about the planet's orbit and minimum mass. A second planet was discovered by the same team two years later. Both planets are greater in mass than Jupiter.

His results showed unequivocally that Meyer's interpretation was the correct one and that nearly all of the new element's properties matched Mendeleev predictions. The close match between what had been predicted for ekasilicon and what was found for germanium was clear evidence for the utility and power of the periodic table and the concept of periodicity.

Dmitri Mendeleev's periodic system proposed in 1871 showing oxygen, sulfur, selenium and tellurium part of his group VI Three of the chalcogens (sulfur, selenium, and tellurium) were part of the discovery of periodicity, as they are among a series of triads of elements in the same group that were noted by Johann Wolfgang Döbereiner as having similar properties. Around 1865 John Newlands produced a series of papers where he listed the elements in order of increasing atomic weight and similar physical and chemical properties that recurred at intervals of eight; he likened such periodicity to the octaves of music. His version included a "group b" consisting of oxygen, sulfur, selenium, tellurium, and osmium. Johann Wolfgang Döbereiner was among the first to notice similarities between what are now known as chalcogens.

It is this periodicity of properties, manifestations of which were noticed well before the underlying theory was developed, that led to the establishment of the periodic law (the properties of the elements recur at varying intervals) and the formulation of the first periodic tables. The periodic law may then be successively clarified as: depending on atomic weight; depending on atomic number; and depending on the total number of s, p, d, and f electrons in each atom. The cycles last 2, 6, 10, and 14 elements respectively. There is additionally an internal "double periodicity" that splits the shells in half; this arises because the first half of the electrons going into a particular type of subshell fill unoccupied orbitals, but the second half have to fill already occupied orbitals, following Hund's rule of maximum multiplicity.

An association between the gamma-ray and x-ray sources was not conclusively made until the ROSAT x-ray imager detected a 237 ms pulsation, which was also seen in gamma- rays by the EGRET instrument and retrospectively in the COS-B and SAS-2 data. Geminga thus appeared to be the first example of a radio-quiet pulsar, and served as an illustration of the difficulty of associating gamma-ray emission with objects known at other wavelengths: some characteristic of the gamma-ray source, such as periodicity or variability, must be identified in candidate counterparts at other wavelengths in order to make the connection of their identity. Finally, this principle held true when radio emissions of matching 237 ms periodicity were found at previously unsurveyed frequencies of 100 MHz and below.

Two nonsingular quadratic forms over F2 are isomorphic if and only if they have the same dimension and the same Arf invariant. This fact was essentially known to , even for any finite field of characteristic 2, and Arf proved it for an arbitrary perfect field. The Arf invariant is particularly applied in geometric topology, where it is primarily used to define an invariant of -dimensional manifolds (singly even-dimensional manifolds: surfaces (2-manifolds), 6-manifolds, 10-manifolds, etc.) with certain additional structure called a framing, and thus the Arf–Kervaire invariant and the Arf invariant of a knot. The Arf invariant is analogous to the signature of a manifold, which is defined for 4k-dimensional manifolds (doubly even-dimensional); this 4-fold periodicity corresponds to the 4-fold periodicity of L-theory.

Created in 1981, it has been held ever since in the month of September and is part of the World Federation of International Music Competitions. After four annual editions, in 1986 it became a biennial competition. In 2004 Valencia's Palau de la Música replaced the city's Teatro Principal as the competition's headquarters. In 2013 the competition was changed to a triennial periodicity.

Why do glaciations occur? The inclination, or tilt, of Earth's axis varies periodically between 22° and 24.5° in a cycle 41,000 years long. The tilt of Earth's axis is responsible for the seasons; the greater the tilt, the greater the contrast between summer and winter temperatures. Precession of the equinoxes, or wobbles of Earth's rotation axis, have a periodicity of 26,000 years.

Marmore's business model revolves around both syndicated research as well as customized research. Marmore's syndicated research is sector/industry specific and aids clients with information and analyses in order to facilitate informed strategic decisions. The company also conducts specialized and customized researches for clients who have specific requirements. Marmore's research offerings encompass a spectrum of periodicity, ranging from daily to yearly publications.

Glass is an amorphous solid. Although the atomic-scale structure of glass shares characteristics of the structure of a supercooled liquid, glass exhibits all the mechanical properties of a solid."Philip Gibbs" Glass Worldwide, (May/June 2007), pp. 14–18 As in other amorphous solids, the atomic structure of a glass lacks the long-range periodicity observed in crystalline solids.

Allowing for this, the star is over 50,000 times as luminous as the sun. Spectral analysis of the star showed that photospheric SiII and HeI lines display a simultaneous, periodic variability. The periodicity was calculated at 1.59 hours in all three lines and it might be the result of stellar oscillations. No clear variation in the brightness has been detected.

Eclipses in the light curve of QR Andromedae are not symmetrical: the ingress is more gradual than the egress. The secondary minimum is variable in occurring phase and depth, meaning that the occultation of the secondary star happens behind a variable part of the disk. Out of the eclipses, light flickering can be clearly seen, and in some observations a periodicity arise.

One of the early discoveries of the CHIME/Fast Radio Burst Project (CHIME/FRB) was the second repeating FRB to be observed, FRB 180814. CHIME/FRB also discovered the first FRB that repeats at regular intervals: 180916.J0158+65 has a periodicity of 16.35 days. At a distance of only 500 million light years, it is also the closest FRB ever discovered.

Weinberg entered the University of Chicago, from which he received his Bachelor of Science (B.S.) degree in physics in 1935, and his Master of Science (M.S.) in physics the following year. He received his Ph.D. from the University of Chicago in mathematical biophysics in 1939, writing his thesis on Mathematical foundations for a theory of biophysical periodicity, under the supervision of Carl Eckart.

Like other human filariasis infections, Brugia timori filariasis causes acute fever and chronic lymphedema. The life cycle of Brugia timori is very similar to that of Wuchereria bancrofti and Brugia malayi, leading to nocturnal periodicity of the disease symptoms. Eosinophilia is common during acute stages of infection. So far Brugia timori has only been found in the Lesser Sunda Islands of Indonesia.

Commercial and recreational use of waterways can be limited significantly by wind direction and speed, wave periodicity and heights, tides, and precipitation. These factors can each influence the safety of marine transit. Consequently, a variety of codes have been established to efficiently transmit detailed marine weather forecasts to vessel pilots via radio, for example the MAFOR (marine forecast).Great Lakes and Seaway Shipping.

It is expected that, over the next several years, this survey will generate over 1000 Terabytes of data. The data is stored at the Cornell University Center for Advanced Computing. The full-resolution raw data is processed independently by three software pipelines. The Cornell University pipeline has conducted standard periodicity search and single-pulse search without doing an acceleration search.

In mathematics, Toda–Smith complexes are spectra characterized by having a particularly simple BP-homology, and are useful objects in stable homotopy theory. Toda–Smith complexes provide examples of periodic self maps. These self maps were originally exploited in order to construct infinite families of elements in the homotopy groups of spheres. Their existence pointed the way towards the nilpotence and periodicity theorems.

Toroidal machines can be axially symmetric, like the tokamak and the reversed field pinch (RFP), or asymmetric, like the stellarator. The additional degree of freedom gained by giving up toroidal symmetry might ultimately be usable to produce better confinement, but the cost is complexity in the engineering, the theory, and the experimental diagnostics. Stellarators typically have a periodicity, e.g. a fivefold rotational symmetry.

A cover of Pantera Bionda. Pantera Bionda was an Italian comics series, launched on 24 April 1948. It featured Pantera Bionda ("Blonde Panther"), a jungle girl inspired by American characters such as Sheena and Nyoka, and was created by writer Gian Giacomo Dalmasso and artist Ingam (Enzo Magni). The series was published by Giurma, first with biweekly and then weekly periodicity.

Goberta (minor planet designation: 316 Goberta) is a mid-sized Themistian asteroid that was discovered by French astronomer Auguste Charlois on 8 September 1891 in Nice.Charlois, A.; Benennung von kleinen Planeten, Astronomische Nachrichten, Vol. 132, No. 3155, p. 175 The light curve of 316 Goberta shows a periodicity of , during which time the brightness of the object varies by in magnitude.

The idea of functional periodicity stems from past cultural superstitions. In the past, menstruation has been thought of as superstitious and taboo. An example of this line of thought comes from the British Medical Journal, which discusses the question of whether or not a menstruating woman can contaminate or damage food by touching it. Many individuals believed in this superstition and reinforced it.

After a meal the amplitude of these oscillations increases but the periodicity remains constant. The oscillations are believed to be important for insulin sensitivity by preventing downregulation of insulin receptors in target cells. Such downregulation underlies insulin resistance, which is common in type 2 diabetes. It would therefore be advantageous to administer insulin to diabetic patients in a manner mimicking the natural oscillations.

The bulk of solid-state physics, as a general theory, is focused on crystals. Primarily, this is because the periodicity of atoms in a crystal — its defining characteristic — facilitates mathematical modeling. Likewise, crystalline materials often have electrical, magnetic, optical, or mechanical properties that can be exploited for engineering purposes. The forces between the atoms in a crystal can take a variety of forms.

Multiplying the stock balance in qty by the Average cost gives the Stock cost at the end of the period. Using the perpetual method, the calculation is done upon every purchase transaction. Thus, the calculation is the same based on the periodic calculation whether by period (periodic) or by transaction (perpetual). The only difference is the 'periodicity' or scope of the calculation.

Thus, signal processing methods can be applied to them after the symbolic string is properly mapped to one (or more) numerical sequences. The reason for this periodicity is due to the biased distribution towards codon triplets, which is a consequence of genetic code degeneracy; while non-coding segments are uniformly randomly distributed and produce no significant signal in the frequency space.

Commercial and recreational use of waterways can be limited significantly by wind direction and speed, wave periodicity and heights, tides, and precipitation. These factors can each influence the safety of marine transit. Consequently, a variety of codes have been established to efficiently transmit detailed marine weather forecasts to vessel pilots via radio, for example the MAFOR (marine forecast).Great Lakes and Seaway Shipping.

HD 166 or V439 Andromedae (ADS 69 A) is a 6th magnitude star in the constellation Andromeda, approximately 45 light years away from Earth. It is a variable star of the BY Draconis type, varying between magnitudes 6.13 and 6.18 with a 6.23 days periodicity. It appears within one degree of the star Alpha AndromedaeAutostar Suite Astronomer Edition. CD-ROM. Meade, April 2006.

2DPs as two dimensional sheet macromolecules have a crystal lattice, that is they consist of monomer units that repeat in two dimensions. Therefore, a clear diffraction pattern from their crystal lattice should be observed as a proof of crystallinity. The internal periodicity is supported by electron microscopy imaging, electron diffraction and Raman- spectroscopic analysis. 2DPs should in principle also be obtainable by, e.g.

The Signpost publishes stories relating to the Wikipedia community, the Wikimedia Foundation, and other Wikipedia- related projects, and is provided free of charge. The Wikipedia community manages the newspaper. From 2005 to March 2016, The Signpost was published on a weekly basis. In April 2016, the nominal periodicity was changed to "fortnightly" (every two weeks) due to a shortage of contributors.

9 Cephei (9 Cep), also known as V337 Cephei, is a variable star in the constellation Cepheus. 9 Cephei was given the name V337 Cephei and classified as an α Cygni variable in 1967. It varies irregularly between magnitude 4.69 and 4.78. A study of the Hipparcos satellite photometry showed an amplitude of 0.56 magnitudes, but could find no periodicity.

"0/2" Dates and ranges of time (CE or AD) in conventional Christian (Gregorian) reckoning "0" First millennium CE "1" Second millennium CE "2" Third millennium CE "3/7" Time divisions other than dates in Christian (Gregorian) reckoning "3" Conventional time divisions and subdivisions: numbered, named, etc. "4" Duration. Time- span. Period. Term. Ages and age-groups "5" Periodicity. Frequency.

Dai et al. (2009) invoke the presence of a third object to explain orbital period variations with an apparent periodicity of roughly 28 years. The third body could yield a minimum mass 20 times greater than Jupiter and be located 9.9 Astronomical Units away from the dwarf nova, being likely a low-mass brown dwarf. Possible makeup of the Z Chamaeleontis Star system.

Observations over five years were not able to establish its periodicity. It is around 1.5 to 2 times as massive as our Sun, and has expanded to about 60 times the Sun's diameter. It shines with about 655 times the luminosity of the Sun. Located 3° northeast of Gamma is the VW Hydri, a dwarf nova of the SU Ursae Majoris type.

In electronics and telecommunications, jitter is the deviation from true periodicity of a presumably periodic signal, often in relation to a reference clock signal. In clock recovery applications it is called timing jitter. Jitter is a significant, and usually undesired, factor in the design of almost all communications links. Jitter can be quantified in the same terms as all time-varying signals, e.g.

The second edition called Gaoua 84 took place the 13–20 December 1984 in the south of the country. At the end of this Edition, some economic problems related to the periodicity of the event arisen. As a result, the organizers decided that the manifestation will take place every two years from now on in Bobo. So the following edition took place in 1986 at Bobo-Dioulasso.

OKW/Chi developed a series of teleprinter tape devices, to examine the periodicity or repetition of text, which employed early designs of photo-electric readers. They employed paper tapes, rather than celluloid film, which was used by the allies. By the end of the war, the first German film device was in construction. TICOM reported that it was similar to the USA developed Tetragraph-Tester (Tetragraph).

Internally, parametric audio coding algorithms operate on 10 ms PCM frames using a model of the human voice. Each of these audio segments is declared voiced (vowel) or unvoiced (consonant). Codec 2 uses sinusoidal coding to model speech, which is closely related to that of multi-band excitation codecs. Sinusoidal coding is based on regularities (periodicity) in the pattern of overtone frequencies and layers harmonic sinusoids.

Cyclin-I is a protein that in humans is encoded by the CCNI gene. The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event.

In tightly packed planetary systems, the gravitational pull of the planets among themselves causes one planet to accelerate and another planet to decelerate along its orbit. The acceleration causes the orbital period of each planet to change. Detecting this effect by measuring the change is known as Transit Timing Variations. "Timing variation" asks whether the transit occurs with strict periodicity or if there's a variation.

The light curve of an intermediate polar may show several types of stable periodic changes in brightness. One periodicity is related to the orbital period of the binary star system. The orbital periods of confirmed intermediate polars range from 1.4 to 48 hours, with typical values between 3 and 6 hours. A second periodic signal originates from the rotation of the white dwarf spinning on its axis.

This is a BY Draconis variable star that undergoes brightness variations due to stellar activity. Differential rotation causes changes to the periodicity of the variation depending on the latitude of the activity. X-ray emission has been detected from AK Leporis, and it is located at or near a radio source. Infrared observation of this star shows a large excess at a wavelength of 24 µm.

During the 17th century there were many kinds of news publications that told both the news and rumours, such as pamphlets, posters and ballads. Even when news periodicals emerged, many of these co-existed with them. A news periodical differs from these mainly because of its periodicity. The definition for 17th century newsbooks and newspapers is that they are published at least once a week.

Haüy was not the only researcher to observe that calcite crystals could be composed of smaller rhombohedra, but it was he who introduced the idea of triple periodicity in crystals. This idea was fundamental to later developments in the field on crystal lattices. Between 1784 and 1822, Haüy published more than 100 reports discussing his theories and their application to the structure of crystalline substances.

Its periodicity is complex, with several different periods of varying lengths, most notably one of 46 days and one of 64 days. Even further north is FL Lyrae, a much fainter 9th-magnitude Algol variable that drops by half a magnitude every 2.18 days during the primary eclipse. Both components are main-sequence stars, the primary being late F-type and the secondary late G-type.

Christian Pedersen Horrebow (April 15, 1718 – September 15, 1776) was a Danish astronomer of the 18th century. He was a son of Peder Horrebow, whom he succeeded as director of the observatory associated with the University of Copenhagen. Neith, a supposed moon of Venus, was spotted by Christian Horrebow, while he was studying this planet from 1766 to 1768. He also discovered the periodicity of sunspots.

But these people, together with Kodaira and Spencer, and my more or less "personal remedial tutor", Arnold Shapiro, were the ones I had the most mathematical contact with.Raoul Bott (1988) "Topological Constraints on Analysis", in A Century of Mathematics in America, Part II, pp 527–42, esp. page 532, American Mathematical Society In 2000 Allyn Jackson interviewed Bott, who then revealed Shapiro’s part in the Periodicity Theorem.

Food habits and feeding periodicity of the Rainbow, Fantail, and Banded darters in Four-Mile Creek. Ohio Journal of Science (77): 164-169. The primary predators of the rainbow darter are larger freshwater fish, such as burbots (Lota lota), stonecats (Noturus flavus), and smallmouth bass (Micropterus dolomieu). Like many other darter species, it has the ability to maintain position on the substrate in flowing water.

The modern understanding of sunspots starts with George Ellery Hale, who linked magnetic fields and sunspots. Hale suggested that the sunspot cycle period is 22 years, covering two polar reversals of the solar magnetic dipole field. Horace W. Babcock proposed in 1961 a qualitative model for solar dynamics. On the largest scale, the Sun supports an oscillatory magnetic field, with a quasi-steady periodicity of 22 years.

A total of were found, and the measurement of their periodicity gave a net distance estimate of (). This is consistent with the distance estimate determined through redshift measurements. As of the time of this study, NGC 4603 was the most distant galaxy for which a distance estimate had been made using Cepheid variable. On May 21, 2008, supernova SN 2008cn was discovered at a position 23.

Note that octaves are usually ignored in constructing periodicity blocks (as they are in scale theory generally) because it is assumed that for any pitch in the tuning system, all pitches differing from it by some number of octaves are also available in principle. In other words, all pitches and intervals can be considered as residues modulo octave. This simplification is commonly known as octave equivalence.

CO.10 [no] #Raspite (Y: 1897) 4.DG.20 (IUPAC: lead tungsten tetraoxide) #Rastsvetaevite (eudialyte: IMA2000-028) 9.CO.10 [no] #Rasvumite (cubanite: IMA1970-028) 2.FB.20 (IUPAC: potassium diiron trisulfide) #Rathite: sartorite group ##(Rathite-I) (sartorite: 1896) 2.HC.05d ##(Rathite-IV)Q (sartorite: 1964) 2.0 [no] [no] (AgxTlyPb16−2(x+y)As16+x+y−zSbzS40) Note: monoclinic phase with 140Å periodicity.

That purely mathematical abstraction is sometimes referred to as impulse sampling. Most sampled signals are not simply stored and reconstructed. But the fidelity of a theoretical reconstruction is a customary measure of the effectiveness of sampling. That fidelity is reduced when s(t) contains frequency components whose periodicity is smaller than two samples; or equivalently the ratio of cycles to samples exceeds ½ (see Aliasing).

The club appendage can sustain high intensity load by shear wave filtering because of the periodicity and chirality of its Bouligand structure. Catastrophic crack growth is hindered in two ways. When crack growth follows the helicoidial structure between layers of chitin fibers, a large surface area per crack length is produced. Therefore, there is high total energy dissipated during club impact and crack propagation.

More recent observations have not detected any regular periodic signal associated with this companion, but argue that the slight variations in pulse arrival times are consistent with an asteroid belt having a total mass less than 0.05 that of the Earth, but acknowledge that the detection of periodicity in pulse timing variations associated with individual asteroids is necessary to confirm the possible asteroid belt.

TV Geminorum is classified as a semi-regular variable star, meaning that its brightness changes are not predictable, but do show some periodicity. The General Catalogue of Variable Stars does not list a period, but the International Variable Star Index gives an uncertain period of 229 days. A detailed study of TV Gem between 1997 and 2014 detects periods of 411 days and 3,137 days.

This method has been applied to sequence data from a number of organisms, details of which can be found in the references section. A few will be summarized here. Tiwari, who wrote the paper to first apply DFT to analyzing periodicity of DNA sequences, applied this method to S.cerevisiae and H.influenzuae. For S.cerevisiae, they were able to locate 413 out of 483 probable genes (ORFs).

The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin forms a complex with CDK7 kinase and ring finger protein MAT1.

The projected rotational velocity may be as high as and it may be rotating at a rate of once per day. This is a young star with an age of only three million years. Its luminosity is varying in a periodic manner similar to that of a Beta Cephei variable. This periodicity has a dozen or more frequencies ranging between 1–10 cycles per day.

Breeding periodicity, productivity and conservation of the Martial Eagle. Ostrich, 58(3), 135-138. During mutual circling, the adult female may turn and present talons. Martial eagles are not known to “cartwheel” which is when two eagles lock feet and circle down, falling almost to the ground, an action that was once thought to be part of breeding displays but is known generally considered territorial in nature.

The Sun, being the closest star to earth, allows a unique chance to study stellar physics with high-resolution. It was, until the 1990s, the only star whose surface had been resolved. General topics that interest a solar astronomer are its 11-year periodicity (i.e., the Solar Cycle), sunspots, magnetic field activity (see solar dynamo), solar flares, coronal mass ejections, differential rotation, and plasma physics.

Another group of algorithms employs a method called sequence self-comparison. Sequence self-comparison programs use databases such as AB-BLAST to conduct an initial sequence alignment. As these programs find groups of elements that partially overlap, they are useful for finding highly diverged transposons, or transposons with only a small region copied into other parts of the genome. Another group of algorithms follows the periodicity approach.

A planetary companion to Gliese 176 was announced in 2008. Radial velocity observations with the Hobby-Eberly Telescope (HET) showed a 10.24-day periodicity, which was interpreted as being caused by a planet. With a semi- amplitude of 11.6 m/s, its minimum mass equated to 24.5 Earth masses, or approximately 1.4 Neptune masses. Observations with the HARPS spectrograph could not confirm the 10.24-day variation.

The events of the cycle are strongly influenced by lighting periodicity. A set of follicles starts to develop near the end of proestrus and grows at a nearly constant rate until the beginning of the subsequent estrus when the growth rates accelerate eightfold. Ovulation occurs about 109 hours after the start of follicle growth. Oestrogen peaks at about 11 am on the day of proestrus.

The periodicity of the chi and psi wheels for each impulse (41 and 43 respectively for the first impulse) is also reflected in the pattern of ΔK. However, given that the psi wheels did not advance for every input character, as did the chi wheels, it was not simply a repetition of the pattern every 41 × 43 = 1763 characters for ΔK1, but a more complex sequence.

In each rotation, plotted under the preceding ones, most sunspots or other phenomena will reappear directly below the same phenomenon on the previous rotation. There may be slight drifts left or right over longer periods of time. The Bartels "musical diagram" or the Condegram spiral plot are other techniques for expressing the approximate 27-day periodicity of various phenomena originating at the solar surface.

See Business Cycle. Calling changes in the stock market as Stock market cycles a "cycle" is a misnomer, because of its non-cyclical nature. Milton Friedman believed that for the most part, excluding very large supply shocks, business declines are more of a monetary phenomenon. Despite the often-applied term cycles, the fluctuations in business economic activity do not exhibit uniform or predictable periodicity.

During much of the 20th century, the converse was also taken for granted – until the discovery of quasicrystals in 1982 showed that there are perfectly deterministic tilings that do not possess lattice periodicity. Besides structural order, one may consider charge ordering, spin ordering, magnetic ordering, and compositional ordering. Magnetic ordering is observable in neutron diffraction. It is a thermodynamic entropy concept often displayed by a second-order phase transition.

Often, extreme events are based on a location's recorded weather history and defined as lying in the most unusual ten percent. In recent years, growing evidence suggests that human-induced global warming is increasing the periodicity and intensity of some extreme weather events.Scientists attribute extreme weather to man-made climate change. Researchers have for the first time attributed recent floods, droughts and heat waves, to human-induced climate change.

The magnitude, shape, periodicity and frequency of the TLM will depend on many factors such as the type of light source, the electrical mains-supply frequency, the driver or ballast technologySee root causes of flicker in Fluorescent lamp lemma. and type of light regulation technology applied (e.g. pulse-width modulation). These TLM properties may vary over time due to aging effects, component failure or end-of-life behavior.

There are also differences in the periodicity of surveys within a country. This project seeks to ensure that statistics are comparable, as far as possible, between countries and over time. This is done using similar definitions of variables in each country/year and applying consistent methods of data processing. In this way SEDLAC allows users to monitor the trends in poverty and other distributional and social indicators in the region.

In 2002 Endl et al. inferred the possible presence of an unseen companion orbiting Beta Hydri as hinted by radial velocity linear trend with a periodicity exceeding 20 years. A substellar object such as a planet with a minimum mass of 4 Jupiter masses and orbital separation of roughly 8 AU could explain the observed trend. If confirmed, it would be a true Jupiter-analogue, though 4 times more massive.

When these icebergs melted they dropped the boulders and other continental rocks they carried, leaving layers known as ice rafted debris. These so-called Heinrich events, named after their discoverer Hartmut Heinrich, appear to have a 7,000–10,000-year periodicity, and occur during cold periods within the last interglacial.Heinrich, H. Origin and Consequences of Cyclic Ice Rafting in the Northeast Atlantic Ocean during the Past 130,000 Years. Quaternary Research, 1988.

There have been several seasons of drought in Afghanistan in recent decades. According to an analysis of climate and drought records Asia Development Bank, localized droughts have a periodicity of three to five years, and droughts covering large areas recur every 9-11 years. South and central areas are more affected from July through September. Afghanistan began experiencing unusual droughts beginning in 1995, right after the Taliban emerged.

Examples of digital dark field bowtie/butterfly detection. Dark field analysis of dual-tetrahedron crystal pairs. Icosahedral twinning has been seen in face-centered-cubic metal nanoparticles that have nucleated: (i) by evaporation onto surfaces, (ii) out of solution, and (iii) by reduction in a polymer matrix. Quasicrystals are un-twinned structures with long range rotational but not translational periodicity, that some initially tried to explain away as icosahedral twinning.

The brightness variations of this star was first noticed in 1935 by M. Fedtke and confirmed by Erich Przybyllok and Kurt Walter the same year. French astronomer Paul Muller then classified Theta Herculis as an irregular variable with a range of magnitudes between 3.7 and 4.1 and a periodicity of roughly 8–9 days. The star is about 130 million years old with 4.94 times the mass of the Sun.

Mathematical modelling has successfully reproduced the periodicity of episodic tremor and slip in the Cascadia region by incorporating this dehydration effect. In this interpretation, tremor may be enhanced where the subducting oceanic crust is young, hot, and wet as opposed to older and colder. However, alternative models have also been proposed. Tremor has been demonstrated to be influenced by tides or variable fluid flow through a fixed volume.

The reason is a minimum in the eccentricity of Earth's orbit around the Sun.” Also, Archer and Ganopolski (2005) report that probable future CO2 emissions may be enough to suppress the glacial cycle for the next 500 kyr. Note in the graphic, the strong 100,000 year periodicity of the cycles, and the striking asymmetry of the curves. This asymmetry is believed to result from complex interactions of feedback mechanisms.

The Journal de St.-Pétersbourg or Journal de Saint-Pétersbourg was a French- language newspaper, published in Saint Petersburg, Russia, with varying periodicity and some interruptions, from 1825 to 1914. For at least some of this period it was an official or semi-official organ of the Russian Foreign Ministry.S.C.M. Paine, The Sino-Japanese War of 1894–1895: Perceptions, Power, and Primacy (Cambridge University Press, 2003), pp. 139–140, 236.

The General Catalogue of Variable Stars gives a magnitude range from +4.23 to +4.54 with a period of 165 days. Other published studies find poorly- defined periodicity, but with possible periods around 270 and 1,300 days. Its infrared magnitude changes much less than the visual magnitude; the visual brightness changes are driven by changes in temperature which shift the proportion of electromagnetic radiation emitted in the visual range.

Right: Periodic voltage response due to flux through a SQUID. The periodicity is equal to one flux quantum, \Phi_0. The DC SQUID was invented in 1964 by Robert Jaklevic, John J. Lambe, James Mercereau, and Arnold Silver of Ford Research Labs after Brian David Josephson postulated the Josephson effect in 1962, and the first Josephson junction was made by John Rowell and Philip Anderson at Bell Labs in 1963.

In 2012, the Okayama Planet Search Program reported the detection of a substellar companion in orbit around HD 5608, based upon Doppler measurements between 2003 and 2011 from the Okayama observatory in Kurashiki. These showed a linear trend indicating the existence of a distant companion. The data showed an additional periodicity of around 766 days. This object shows a minimum mass of , a semimajor axis of , and an eccentricity of 0.19.

In a pure metal, because of the periodicity of the lattice, the features of its electronic structure are well known. The single-particle states can be described in terms of Bloch states, the energy structure is characterized by Brillouin zone boundaries, energy gaps and energy bands. In reality though no metal is perfectly pure. When the amount of the foreign element is dilute, the added atoms may be treated as impurities.

In this regime, the single particle dispersion relation can host a BEC in each minima. The result is that the BEC has 2 momentum components which can interfere in real space. The interference pattern will appear as fringes in the density of the BEC. The periodicity of the fringes is a result of the Raman coupling beam wavelength modified by the coupling strength and by interactions within the BEC.

4, 374–382. with Allyn Jackson of the American Mathematical Society, he explained that he sees "networks as discrete versions of harmonic theory", so his experience with network synthesis and electronic filter topology introduced him to algebraic topology. Bott met Arnold S. Shapiro at the IAS and they worked together. He studied the homotopy theory of Lie groups, using methods from Morse theory, leading to the Bott periodicity theorem (1957).

Svea (minor planet designation: 329 Svea) is an asteroid from the asteroid belt and the namesake of the small Svea family, approximately in diameter. The C-type asteroid and is probably composed of carbonaceous material. It was discovered by Max Wolf on 21 March 1892 in Heidelberg. The light curve of 329 Svea shows a periodicity of , during which time the brightness of the object varies by in magnitude.

Earth’s magnetism was a continuous concern of Ștefan Procopiu, For 25 years he studied this phenomenon in Romania and developed the magnetic maps of the country. He also identified the magnetic anomaly located on the Iași-Botoșani line. In 1947, Procopiu identified a variation of the Earth's magnetic field, with a periodicity of approximately 500 years, indicating that, starting 1932 Earth's magnetic moment increases from the equator to the poles.

The perfect lens solution in the absence of losses is again, not practical, and can lead to paradoxical interpretations. It was determined that although resonant surface plasmons are undesirable for imaging, these turn out to be essential for recovery of decaying evanescent waves. This analysis discovered that metamaterial periodicity has a significant effect on the recovery of types of evanescent components. In addition, achieving subwavelength resolution is possible with current technologies.

Oxford: Oxford University Press. 'This refers to a process whereby an emotion is evoked by a piece of music because a powerful, external rhythm in the music influences some internal bodily rhythm of the listener (e.g. heart rate), such that the latter rhythm adjusts toward and eventually 'locks in' to a common periodicity. The adjusted heart rate can then spread to other components of emotion such as feeling, through proprioceptive feedback.

The refractory period also determines the velocity (distance between wave fronts per unit time) and periodicity (average time interval between wave- induced calcium transients or depolarizations recorded in a particular neuron in the ganglion cell layer) The density of refractory cells corresponds to how fast retinal waves propagate, for instance if there is a low number or density of refractory cells, the velocity of propagation will be high.

This C can come from parasitics of a second stage. These delay lines do not have a flat dispersion near their cut off, so it is important to use the same L-C periodicity in the input and the output. If inserting transmission lines, input and output will disperse away from each other. For a distributed amplifier the input is fed in series into the amplifiers and parallel out of them.

Jitter is the undesired deviation from true periodicity of an assumed periodic signal in electronics and telecommunications, often in relation to a reference clock source. Jitter may be observed in characteristics such as the frequency of successive pulses, the signal amplitude, or phase of periodic signals. Jitter is a significant, and usually undesired, factor in the design of almost all communications links (e.g., USB, PCI-e, SATA, OC-48).

Blowing over the edge of a jug or bottle can create a nearly pure tone of low frequency. The driving force is the flow over the jug edge, so one might expect an edge-tone dipole sound field. In this case, The curvature and roundness of the edge makes a strong edge tone unlikely. Any periodicity at the edge is likely submerged in the class III feedback from the jug volume.

The cancer associated, drug responsive variant of ENOX, tNOX, arises as a splice variant and is found on the cell surface of human cancers. tNOX exhibits a periodicity of 22 minutes, compared to the native 24 minutes and can be inhibited by a number of anticancer drugs, without affecting the native ENOX. These properties of tNOX are being used to develop early detection and intervention mechanisms for human cancers.

The Mineralogical Record is a mineralogy magazine, published in the United States by The Mineralogical Record Inc. with a periodicity of six issues a year, totaling approximately 700 pages. Publish, in English, articles on topographic mineralogy, including locations around the world an also articles in specimen-oriented mineralogy. He also publishes chronicles on the main mineral fairs, and occasionally, articles on the history of mineralogy and on museums and mineral collections.

Thus there is a diurnal (time of day) effect and a seasonal effect. The local winter hemisphere is tipped away from the Sun, thus there is less received solar radiation. The activity of the Sun modulates following the solar cycle, with more radiation occurring with more sunspots, with a periodicity of around 11 years. Radiation received also varies with geographical location (polar, auroral zones, mid-latitudes, and equatorial regions).

Figure 2: A modern version of the Mauders' sunspot "butterfly diagram". (This version from the solar group at NASA Marshall Space Flight Center.) Part of Maunder's job at the Observatory involved photographing and measuring sunspots, and in doing so he observed that the solar latitudes at which sunspots occur varies in a regular way over the course of the 11-year cycle. After 1891, he was assisted in his work by his wife Annie Maunder. In 1904, he published their results in the form of the "butterfly" diagram. After studying the work of Gustav Spörer,Spörer (1887) "Über die Periodicität der Sonnenflecken seit dem Jahre 1618, vornehmlich in Bezug auf die heliographische Breite derselben, und Hinweis auf eine erhebliche Störung dieser Periodicität während eines langen Zeitraumes" (On the periodicity of sunspots since the year 1618, especially with respect to the heliographic latitude of the same, and reference to a significant disturbance of this periodicity during a long period), Vierteljahrsschrift der Astronomischen Gesellschaft (Leipzig), 22 : 323-329.

Spawning cycles in V. moorii correspond to the lunar cycle, with egg-laying taking place just before the full moon. This lunar-related reproductive periodicity is rare in freshwater organisms and far more common in organisms in marine environments. This periodicity probably evolved to decrease risk of predation when the fry are in their most vulnerable stages (as eggs and larvae), since the moon is at its brightest and the parents can best defend against nocturnal fry-eating fish. Such nocturnal predators also tend to avoid or move away from light and thus hunt less during the full moon. This lunar synchronicity confers greater benefit to V. moorii compared to other freshwater fish species because of V. moorii’s location in the tropical zone where the moonlight is more intense (since it is more perpendicular to the surface) and V. moorii tend to live in shallow waters that are easily penetrated by moonlight.

Fundamentally SDWs and CDWs involve the development of a superstructure in the form of a periodic modulation in the density of the electronic spins and charges with a characteristic spatial frequency q that does not transform according to the symmetry group that describes the ionic positions. The new periodicity associated with CDWs can easily be observed using scanning tunneling microscopy or electron diffraction while the more elusive SDWs are typically observed via neutron diffraction or susceptibility measurements. If the new periodicity is a rational fraction or multiple of the lattice constant, the density wave is said to be commensurate; otherwise the density wave is termed incommensurate. A sketch in k-space of a (001) section of the Fermi surface of Cr. The band structure of Cr yields an electron pocket (green) centered at Gamma and a hole pocket (blue) centered at H. The surrounding black square indicates the boundary of the first Brillouin zone.

He survived the war. During the 1950s he studied the longer eclipse cycles, allowing him to predict solar and lunar eclipses over a long time interval. This was published in 1951 as Regelmaat en wisseling bij zonsverduisteringen, met een aanhangsel over maansverduisteringen and translated into English in 1955 as Periodicity and Variation of Solar (and Lunar) Eclipses. In 1958 he developed a compressed form of typesetting called Hoofdletters, published as Hoofdletters, Tweeling- en Meerlingdruk.

Explorer 50 was a drum-shaped spacecraft, across and height, with propulsion Star-17A, instrumented for interplanetary and magnetotail studies of cosmic rays, energetic solar particles, plasma, and electric and magnetic fields. Its initial orbit was more elliptical than intended, with apogee and perigee distances of about 45 earth radii and 25 earth radii. Its eccentricity decreased after launch. Its orbital inclination varied between 0° and about 55° with a periodicity of several years.

Hypotheses have also advanced toward linking reversals to mass extinctions. Many such arguments were based on an apparent periodicity in the rate of reversals, but more careful analyses show that the reversal record is not periodic. It may be, however, that the ends of superchrons have caused vigorous convection leading to widespread volcanism, and that the subsequent airborne ash caused extinctions. Tests of correlations between extinctions and reversals are difficult for a number of reasons.

The first published use was in the successful search for light variablility in the star HD 173650, published in 1962 and using data from the summer of 1960. In later work using data from this instrument, William Wehlau pioneered Fourier techniques of detecting multiple periodicities in stars. The ground breaking work was the paper "The Multiple Periodicity of Delta Delphinii", Ap.J., Vol.139,April 1964, co- authored with graduate student Kam-Ching Leung.

Edward Nikolayevich Trifonov (, ; b. March 31, 1937) is a Russian-born Israeli molecular biophysicist and a founder of Israeli bioinformatics. In his research, he specializes in the recognition of weak signal patterns in biological sequences and is known for his unorthodox scientific methods. He discovered the 3-bp and 10-bp periodicity in the DNA sequences, as well as the rules determining the curvature of DNA molecules and their bending within nucleosomes.

Optical systems, and in particular optical aberrations are not always rotationally symmetric. Periodic patterns that have a different orientation can thus be imaged with different contrast even if their periodicity is the same. Optical transfer function or modulation transfer functions are thus generally two-dimensional functions. The following figures shows the two-dimensional equivalent of the ideal and the imperfect system discussed earlier, for an optical system with trefoil, a non-rotational- symmetric aberration.

If it is not, we toss another biased coin, Coin 3, with probability of winning P_3=(3/4)-\epsilon. The role of modulo M provides the periodicity as in the ratchet teeth. It is clear that by playing Game A, we will almost surely lose in the long run. Harmer and Abbott show via simulation that if M=3 and \epsilon = 0.005, Game B is an almost surely losing game as well.

6-light saloon 6-light saloon 4-light sports saloon A number of important improvements were made to the front part of the chassis though it retained the same dimensions. Suspension and steering were changed. To reduce fore and aft movement as much as possible the front springs were lengthened and made more supple in order to bring their periodicity nearer that of the rear springs. Steering was changed to the worm and nut system.

As they assume a more stable phase relationship, the amount of energy gradually reduces to zero, with systems of greater frequency slowing down, and the other speeding up.Bennett, M., Schatz, M. F., Rockwood, H., and Wiesenfeld, K., Huygens's clocks. Proceedings: Mathematics, Physical and Engineering Sciences, 2002, pp563-579. Subsequently, the term 'entrainment' has been used to describe a shared tendency of many physical and biological systems to synchronize their periodicity and rhythm through interaction.

The most heavily studied cathemeral lemurs are the true lemurs. Although the mongoose lemur (E. mongoz) is the best-documented example, every species in the genus studied has shown some degree of cathemeral behavior, although night activity is often restricted by light availability and moon periodicity. This type of behavior was first documented in the 1960s in true lemur species as well as other Lemuridae species, such as ruffed lemurs and bamboo lemurs.

Oscillators produce various levels of phase noise, or variations from perfect periodicity. Viewed as an additive noise, phase noise increases at frequencies close to the oscillation frequency or its harmonics. With the additive noise being close to the oscillation frequency, it cannot be removed by filtering without also removing the oscillation signal. All well-designed nonlinear oscillators have stable limit cycles, meaning that if perturbed, the oscillator will naturally return to its periodic limit cycle.

The first known description of an emergence of Brood X appeared a May 9, 1715, entry in the journal of Rev. Andreas Sandel, the pastor of Philadelphia's "Gloria Dei" Swedish Lutheran Church. In 1737, botanist John Bartram wrote a letter that described the periodicity of the brood's emergences and his 1732 observations of the insect's insertion of their eggs into the small branches of trees northwest of Philadelphia.(1) (2) Kritsky, 2004, pp. 44-46.

Metamaterials were originally researched as a passive response material. The passive response was and still is determined by the patterning of the metamaterial elements. In other words, the majority of research has focused on the passive properties of the novel transmission, e.g., the size and shape of the inclusions, the effects of metal film thickness, hole geometry, periodicity, with passive responses such as a negative electric response, negative index or gradient index etc.

The window length L determines the longest periodicity captured by SSA. Trends can be extracted by grouping of eigentriples with slowly varying eigenvectors. A sinusoid with frequency smaller than 0.5 produces two approximately equal eigenvalues and two sine-wave eigenvectors with the same frequencies and \pi/2-shifted phases. Separation of two time series components can be considered as extraction of one component in the presence of perturbation by the other component.

His main research effort in meteorology went into examining long-time series for regularities; he was more concerned with establishing the regularities than in explaining them. He made no contributions to the theory of meteorology which is perhaps surprising given his training in physics. The contrast with his American contemporary, William Ferrel, who discovered Buys-Ballot's law slightly earlier, is striking. Buys Ballot devised a tabular method for investigating periodicity in time series.

Rck-2 is a gene that plays a major role in clock control of translation. Rck-2 protein is a kinase and is rhythmically activated through phosphorylation events based on the periodicity of the clock. Rck-2 activation is directly associated with the phosphorylation of eEF-2, which is an elongation factor that plays a major role in translation. Phosphorylation of eEF-2 has an inhibitory effect on the activity of translation.

Their original title was I libri gialli, where giallo in Italian means "yellow", a reference to the color of the cover background. The title was changed to I gialli Mondadori in 1946. The series had a weekly periodicity for decades, while currently is published every fifteen days. In its long life, the series spawned several companion series, the most successful being I classici del Giallo, which is still ongoing and publishes reprints.

There is a minimum possible wavelength, given by twice the equilibrium separation a between atoms. Any wavelength shorter than this can be mapped onto a wavelength longer than 2a, due to the periodicity of the lattice. This can be thought as one consequence of Nyquist–Shannon sampling theorem, the lattice points are viewed as the "sampling points" of a continuous wave. Not every possible lattice vibration has a well-defined wavelength and frequency.

378–379 The modulation of the radio emissions by planetary rotation is traditionally used to determine the rotation period of the interiors of fluid giant planets.Zarka, 2007 In the case of Saturn, however, this appears to be impossible, as the period varies at the timescale of tens years. In 1980–1981 the periodicity in the radio emissions as measured by Voyager 1 and 2 was , which was then adopted as the rotational period of Saturn.

It exhibits a banded pattern similar to Jupiter's, and occasionally exhibits long-lived ovals caused by storms. A storm formation analogous to Jupiter's Great Red Spot, the Great White Spot, is a short-lived phenomenon that forms with a roughly 30-year periodicity. It was last observed in 1990. However, the storms and the band pattern are less visible and active than those of Jupiter, due to the overlying ammonia hazes in Saturn's troposphere.

A recurrent flagellum is attached to the cell body by an undulating membrane and is free at the posterior end. The undulating membrane travels along the lateral groove and is supported by a conspicuous costa with type B periodicity. Four flagella are free and emerge anterolaterally from the lateral groove. The sixth flagellum emerges from a basal body the dorsal side of the body, independent of the basal body complex of the other flagella.

Sapropel (a contraction of ancient Greek words sapros and pelos, meaning putrefaction and mud (or clay), respectively) is a term used in marine geology to describe dark-coloured sediments that are rich in organic matter. Organic carbon concentrations in sapropels commonly exceed 2 wt.% in weight. The term sapropel events may also refer to cyclic oceanic anoxic event (OAE), in particular those affecting the Mediterranean Sea with a periodicity of about 21,000 years.

There is another infinite-dimensional unitary group, of major significance in homotopy theory, that to which the Bott periodicity theorem applies. It is certainly not contractible. The difference from Kuiper's group can be explained: Bott's group is the subgroup in which a given operator acts non-trivially only on a subspace spanned by the first N of a fixed orthonormal basis {ei}, for some N, being the identity on the remaining basis vectors.

Functional periodicity was the idea of women being functionally impaired during their menstruation cycle. The untested hypothesis of the time was supported by men, because at this time they dominated society, and this idea helped to keep women in a subordinate position. Women were viewed as not qualified for certain types of work, achievements, and certain responsibilities. The belief also reinforced the stereotype of women being fragile in physical and emotional well-being.

The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns that contribute to the temporal coordination of each mitotic event. This cyclin tightly associates with CDK9 kinase, and was found to be a major subunit of the transcription elongation factor p-TEFb.

In addition, this demonstration was thought to be experimental evidence that a planar DNG metamaterial would refocus the far field radiation of a point source. However, the perfect lens would require significantly different values for permittivity, permeability, and spatial periodicity than the demonstrated negative refractive sample. This study agrees that any deviation from conditions where ε=µ=−1 results in the normal, conventional, imperfect image that degrades exponentially i.e., the diffraction limit.

In addition to teaching at Auckland and Hawaii, Green periodically held active teaching and research positions at the American Museum of Natural History in New York, the Bernice P. Bishop Museum in Honolulu, and Te Whare Wānanga o Awanuiārangi in Whakatane, New Zealand. He also oversaw the funding of numerous research projects through the Green Foundation for Polynesian Research.For example, Allen, M.S. 2006. Periodicity, duration, and function of occupation at Tauroa Point, Northland, New Zealand.

It is a suspected slow irregular variable with a periodicity of roughly 1,100 days. The measured angular diameter, after correction for limb darkening, is . At the estimated distance of the star, this yields a physical size of about 53 times the radius of the Sun. It has an estimated 1.7 times the mass of the Sun and is radiating 834 times the solar luminosity from its photosphere at an effective temperature of 3,958 K.

Pahal (meaning A beginning in Hindi) is one of the most influential literary magazines in the Hindi language that has seen uninterrupted publication since 1973. Brought out by Gyanranjan, noted Hindi novelist and short-story writer, from Jabalpur, the magazine publishes poetry, fiction, non-fiction, critique and essays concentrating on issues of contemporary interest. Although the publication does not have a declared periodicity, three to four issues are normally brought out every year.

In time- dependent models the probability of a fault rupturing thus depends on how long stress has been accumulating since the last rupture. However, the details of how this happens are not adequately known, so time-dependent methods estimate the periodicity and currently accumulated strain based on observed seismicity. Out of this a time-independent earthquake rate model (ERM) is produced, from which the time-dependent probability model (UCERF) is derived.UCERF, p. 12.

The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin and its kinase partner CDK9 were found to be subunits of the transcription elongation factor p-TEFb.

In the past this star has been considered a member of the open cluster NGC 1252, but this now seems unlikely. This is an aging red giant star on the asymptotic giant branch with a stellar classification of C-N4IIIb:. It is one of the brightest carbon stars and has a type of C2 3.5. The star is classified as a semiregular variable of type SRb and has a periodicity of 158 days.

Due to the periodic grating, the phase matching between the incident light and the guide mode is easy to obtain. According to Equation 7, the propagation vector (Kz) in the z direction can be tuned by changing the periodicity Λ. The grating vector can be modified, and the angle of resonant excitation can be controlled. In Figure 9, q is the diffraction order it can have values of any integer (positive, negative or zero).

The three fundamental propositions expounded in The Secret Doctrine are – v. II, p. 245-246 # that there is an omnipresent, eternal, boundless, and immutable reality of which spirit and matter are complementary aspects; # that there is a universal law of periodicity or evolution through cyclic change; and # that all souls are identical with the universal oversoul which is itself an aspect of the unknown reality. Helena Blavatsky taught that Theosophy is neither revelation nor speculation. p.

This is a list of issue covers of the Brazilian edition of Playboy magazine. The entries on this table include each cover's subjects. This list is for the regular monthly issues of the Brazilian Playboy, as well as its 1975-1980 predecessor, A Revista do Homem; any one-time-only special issues are not included. While a monthly magazine under Editora Abril, the magazine has had uneven periodicity since its change to dedicated publisher PBB Entertainment in 2016.

The randomness of the reversals is inconsistent with periodicity, but several authors have claimed to find periodicity.e.g., However, these results are probably artifacts of an analysis using sliding windows to attempt to determine reversal rates. Most statistical models of reversals have analyzed them in terms of a Poisson process or other kinds of renewal process. A Poisson process would have, on average, a constant reversal rate, so it is common to use a non-stationary Poisson process.

One fascinating field in which SMPs are impacting quite significantly nowadays is photonics. Due to the shape changing capability, SMPs enable the production of functional and responsive photonic gratings. In fact, by using modern soft lithography techniques such as replica molding, it is possible to imprint periodic nanostructures, with sizes of the order of magnitude of visible light, onto the surface of shape memory polymeric blocks. As a result of the refractive index periodicity, these systems diffract light.

Cogging torque of electrical motors is the torque due to the interaction between the permanent magnets of the rotor and the stator slots of a Permanent Magnet (PM) machine. It is also known as detent or 'no-current' torque. This torque is position dependent and its periodicity per revolution depends on the number of magnetic poles and the number of teeth on the stator. Cogging torque is an undesirable component for the operation of such a motor.

Generational change drives the cycle of turnings and determines its periodicity. As each generation ages into the next life phase (and a new social role) society's mood and behavior fundamentally changes, giving rise to a new turning. Therefore, a symbiotic relationship exists between historical events and generational personas. Historical events shape generations in childhood and young adulthood; then, as parents and leaders in midlife and old age, generations in turn shape history.Strauss & Howe 1997, pp. 58p62.

Brainwaves, or neural oscillations, share the fundamental constituents with acoustic and optical waves, including frequency, amplitude and periodicity. Consequently, Huygens' discovery precipitated inquiry into whether or not the synchronous electrical activity of cortical neural ensembles might not only alter in response to external acoustic or optical stimuli but also entrain or synchronize their frequency to that of a specific stimulus.Will, U., and Berg, E., "Brainwave synchronization and entrainment to periodic stimuli" Neuroscience Letters, Vol. 424, 2007, pp 55–60.

Maximum pheromone titer is from day one to day five, and then decreases. The highest concentration of the major female sex pheromone, (Z)-9 hexadecenal (Z9-Z16:Al), is released in a distinct pattern over a 24-hour period or a circadian periodicity. This pattern is affected by age, photoperiod, and temperature. The daily rhythm of hormone production varies when the female moths are reared under 12 hours of light and 12 hours of darkness vs.

The World Judo Championships are the highest level of international judo competition, along with the Olympic judo competition. The championships are held once every year (except the years when the Olympics take place) by the International Judo Federation, and qualified judoka compete in their respective categories as representatives of their home countries. Team competitions have also been held since 1994. The men's championships began in 1956, though the format and periodicity of the championships have changed over time.

One of the most characteristic behavioural features of plankton is a vertical migration that occurs with a 24-hour periodicity. This has often been referred to as diurnal or diel vertical migration. The vertical distance travelled over 24 hours varies, generally being greater among larger species and better swimmers. But even small copepods may migrate several hundred meters twice in a 24-hour period, and stronger swimmers like euphausiids and pelagic shrimp may travel 800 m or more.7\.

Recently, the use of alternating layers of organic and inorganic compounds has been controlled through electrodeposition-based self-assembly. This is of particular interest because it has been shown that the lamellar structure and periodicity of the alternating organic-inorganic layers can be controlled through solution chemistry. To produce this type of cell with practical efficiencies, larger organic surfactants that absorb more of the visible spectrum must be deposited between the layers of electron-accepting inorganic.

The mature ova measure across and are not enclosed in a capsule. The reproductive cycle has been estimated at 2 years with ovulation taking place in spring, though this periodicity is ill-defined. The litter size ranges from seven to 25 and is correlated with the size of the mother; the young are gestated for 8–10 months. Parturition occurs from December to February in the Mediterranean and in July off England, with the newborns measuring long.

When infected with P. coatneyi, the host shows the general symptoms of malaria are fever, headache, chills, vomiting, diarrhea, jaundice, joint pain and anemia. These symptoms occur in the form of paroxysmal attacks, which is a sudden increase of these symptoms after a period of remission. This is due to the release of merozoites from schizonts inside the red blood cells. This cyclic cycle occurs every other day when infected with P. coatneyi, a tertiary periodicity.

The variability of LL Andromedae is similar to the WZ Sagittae type of dwarf novae. Those have a long outbursts cycle (they were observed only in 1979, 1994 and 2004) and superhumps can be observed with a short periodic modulation. It was observed also a periodicity of 1.32 hours, which is attributed to the orbital period of the system. However, in comparison to WZ Sagittae, the outburst amplitude is small and the superoutbursts duration is short.

RACSAM (Revista de la Real Academia de Ciencias Exactas, Físicas y Naturales, Serie A Matemáticas, Journal of the Spanish Royal Academy of Sciences, Series A Mathematics) is the mathematical journal of the Spanish Royal Academy of Sciences published by Springer since 2011, with a periodicity of four issues per year. It publishes original high-quality research papers in English, covering the areas of Algebra, Applied Mathematics, Computational Sciences, Geometry and Topology, Mathematical Analysis, Statistics and Operations Research.

The Journal of Biological Rhythms has been the official journal for the Society for Research on Biological Rhythms since the founding of both in 1986. The JBR publishes scholarly articles, original research, and reviews on a variety of topics all centering around periodicity in organisms. The journal focuses on circadian and seasonal rhythms, but articles about other biological periods are published as well. A variety of approaches are explored by the journal including: genetic, behavioral, modeling, and clinical trials.

285 Inorganic Chemist's Periodic Table (2002), which emphasizes trends and patterns, and unusual chemical relationships and properties. Near the physics end of the continuum is Janet's Left-Step Periodic Table (1928). This has a structure that shows a closer connection to the order of electron-shell filling and, by association, quantum mechanics. A somewhat similar approach has been taken by Alper, albeit criticized by Eric Scerri as disregarding the need to display chemical and physical periodicity.

Neurons in higher auditory pathway centers are tuned to specific stimuli features, such as periodicity, sound intensity, amplitude and frequency modulation. There are also neuroanatomical associations of ASA through the posterior cortical areas, including the posterior superior temporal lobes and the posterior cingulate. Studies have found that impairments in ASA and segregation and grouping operations are affected in patients with Alzheimer's disease.Goll, J., Kim, L. (2012), "Impairments of auditory scene analysis in Alzheimer's disease", Brain 135 (1), 190-200.

The wave nature of light becomes important at small scales such as those in ASPs, meaning a pure-moire model of ASP function is insufficient. However, at half-integer multiples of the Talbot depth, the periodicity of the diffraction grating is recapitulated, and the moire effect is rescued. By building ASPs where the vertical separation between the gratings is approximately equal to a half-integer multiple of the Talbot depth, the sinusoidal sensitivity with incident angle is observed.

Análise Editorial is a Brazilian publishing house headquartered in the city of São Paulo. The company, founded in 2005 by partners Silvana Quaglio, Alexandre Secco and Eduardo Oinegue, produces segmented journalistic content aimed at Brazilian and global economic analysis. The first publication, Análise International Trade, was launched in 2005.Meio & Mensagem, December 15, 2010, "Análise Editorial celebrates five years of existence" Between 2005 and 2010, Análise Editorial launched ten new titles with annual periodicity and special editions.

He assisted C. V. Boys in radio-micrometer experiments, in timing the periodicity of spark generators' electrical discharges, and in photographing the flight of bullets. He worked with J. W. Rodger in investigating the magnetic rotation of the plane of polarisation in liquids. He designed and built self-recording magnetographs which were used at Kew, Eskadalemuir, and other observatories. His textbooks of physics, Textbook of Physics, Intermediate Physics, and Practical Physics, became popular and were widely used.

The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin forms a complex with and functions as a regulatory subunit of CDK2, whose activity is required for cell cycle G1/S transition.

The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin forms a complex with and functions as a regulatory subunit of CDK4 or CDK6, whose activity is required for cell cycle G1/S transition.

In 1937, Astbury became interested in DNA and directed Bell to work on the molecule. Bell came up with a method to stretch out the fibers to make dried films of purified DNA, with which she took x-ray diffraction photographs that were clearer than previous work. Her work confirmed it was a regular, ordered structure with periodicity of 3.3 - 3.4 Å along the axis. She studied the nucleic acids in yeast, pancreases, tobacco mosaic virus and calf thymus.

In the study of solids, the study of the dispersion relation of electrons is of paramount importance. The periodicity of crystals means that many levels of energy are possible for a given momentum and that some energies might not be available at any momentum. The collection of all possible energies and momenta is known as the band structure of a material. Properties of the band structure define whether the material is an insulator, semiconductor or conductor.

Although that deficiency was considered statistically insignificant, the overall conclusion was that "the seismic window theory fails as a reliable method of earthquake prediction.". A subsequent study in 2004 found slightly more M > 7.0 earthquakes than expected in seismic windows in a ten-year period, but this evened out in longer periods, and overall syzygy considerations were found to have no predictive value.. Other studies (e.g., ) have found no fortnightly tidal periodicity, either globally, or for southern California specifically.

CC Andromedae (CC And) is a variable star in the constellation Andromeda. It is a pulsating star of the Delta Scuti type, with an apparent visual magnitude that varies between 9.19 and 9.46 with a periodicity of 3 hours. The stellar classification of CC Andromedae is F3IV-V, as it shows intermediate characteristics between a subgiant and a main sequence star. The brightness variations are the result of 7 different pulsation modes, most of which are non-radial.

The primary component, τ9 Eri A, is a magnetic chemically peculiar star with a stellar classification of , indicating that it is a B-type main sequence star that shows abundance anomalies in its silicon absorption lines. It is an Alpha² Canum Venaticorum variable with a rotational periodicity of 5.954 days. The averaged strength of the stellar effective magnetic field is . Tau9 Eridani A has an estimated 326% the mass of the Sun and 3.1 times the Sun's radius.

Given the knowledge from Tutte's work, of the periodicity of each of the wheels, this allowed the propagation of these values at the appropriate positions in the rest of the key. A set of five sheets, one for each of the chi wheels, was also prepared. These contained a set of columns corresponding in number to the cams for the appropriate chi wheel, and were referred to as a 'cage'. So the \chi3 cage had 29 such columns.

What makes the Whittle likelihood only approximately accurate is related to the sampling theorem—the effect of Fourier-transforming only a finite number of data points, which also manifests itself as spectral leakage in related problems (and which may be ameliorated using the same methods, namely, windowing). In the present case, the implicit periodicity assumption implies correlation between the first and last samples (x_1 and x_N), which are effectively treated as "neighbouring" samples (like x_1 and x_2).

This variation has an average periodicity of 3.8285 days, but the brightness also changes over the course of several years--depending on the level of surface activity. Most observers believe that the primary star (A) is responsible for the variability as the secondary produces only a third of the total luminosity from the system. However, the spots may occur on both stars. Unlike the Sun, these spots may occur in the polar regions of the stars.

Based on the about 150-year instrumental record a quasi-periodicity of about 70 years, with a few distinct warmer phases between ca. 1930–1965 and after 1995, and cool between 1900–1930 and 1965–1995 has been identified. In models, AMO-like variability is associated with small changes in the North Atlantic branch of the Thermohaline Circulation. However, historical oceanic observations are not sufficient to associate the derived AMO index to present-day circulation anomalies.

She listed over 259 stars with irregular periodicity variability, examined their galactic distribution, arranged by spectral type. Most spectra lacked the lines typical of the Mira variable stars. She discovered that the light curves of some stars could be interpreted as interference between two or more simultaneous, periodic events in the stars. Her academic career was stopped short because of World War II and she started work at the Swedish National Defence Radio Establishment as a cryptographer systems analyst.

Phase noise measured by signal source analyzer (SSA). The SSA shows the positive part of the phase noise. In this picture there is a phase noise of the main carrier, 3 other signals and "noise hill". A weak signal disappears in the phase noise of the stronger signal In signal processing, phase noise is the frequency-domain representation of random fluctuations in the phase of a waveform, corresponding to time-domain deviations from perfect periodicity ("jitter").

This planet received the designation 55 Cancri d. At the time of discovery, the planet was thought to be in an orbit of mild eccentricity (close to 0.1), but this value was increased by later measurements. Even after accounting for these two planets, a periodicity at 43 days remained, possibly due to a third planet. Measurements of the star suggested that this was close to the star's rotation period, which raised the possibility that the 43-day signal was caused by stellar activity.

Differences in Bone Microstructure of Mammalian Skeletons. Faculty of Natural Sciences, Constantine the Philosopher University in Nitra: Nitra, Slovakia More research is needed, but osteohistology has the potential to positively affect the studies in bioarchaeology, paleontology and forensic investigations. In recent decades, osteohistological studies of dinosaur fossils have been used to address a number of issues, such as the periodicity of growth of dinosaurs and whether it was uniform across species and the question of whether dinosaurs were warm- blooded or not.

He was enthusiastically devoted to Astronomy and Meteorology. From an early period in his life, he was an observer of the heavens, and an accurate recorder of his observations. He rendered important services in determining the periodicity of meteoric showers, and discovered by his own researches the return of the August Perseids. He took great pains to collect information respecting the paths of remarkable meteors of which he heard, and to look up historical notices of those of earlier years.

The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance throughout the cell cycle. Cyclins function as regulators of CDKs (Cyclin-dependent kinase). Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin forms a complex with and functions as a regulatory subunit of CDK4 or CDK6, whose activity is required for cell cycle G1/S transition.

The José Saramago Literary Prize has been awarded since 1999 by the Circulo de Leitores Foundation to a literary work written in Portuguese by a young author in which the first edition was published in a Lusophone country.It celebrates the attribution of the Nobel Prize in Literature in 1998 to the Portuguese writer José Saramago. The prize has a biannual periodicity, and a monetary value of . The jury is composed by 5 to 10 elements of distinguished merit in cultural stances.

Becker and Dehlinger had already predicted a negative diffusivity inside the spinodal region of a binary system. But their treatments could not account for the growth of a modulation of a particular wavelength, such as was observed in the Cu-Ni-Fe alloy. In fact, any model based on Fick's law yields a physically unacceptable solution when the diffusion coefficient is negative. The first explanation of the periodicity was given by Mats Hillert in his 1955 Doctoral Dissertation at MIT.

In 2005, the Anglo-Australian Planet Search program announced the discovery of a low-mass planet in orbit around HD 117618. This object was found through measurements of radial velocity variation, which were larger than those produced by the intrinsic jitter of the host star. The best Keplerian fit to the data gave a periodicity of 25.8 days with an eccentricity of around 0.37 and a semimajor axis of . The lower bound on the object's mass was estimated to be .

The observational characteristic that most clearly defines an intermediate polar is the existence of a spin period signal that is shorter than the orbital period. The known periods range from 33 to 4022 seconds. The physical cause of optical spin-period oscillations is usually attributed to the changing viewing aspect of the accretion curtain as it converges near the white dwarf. A third light curve periodicity, the sideband period between the spin period and the orbital period, is also often present.

Light curve of semiregular variable star Betelgeuse Semiregular variable stars are giants or supergiants of intermediate and late spectral type showing considerable periodicity in their light changes, accompanied or sometimes interrupted by various irregularities. Periods lie in the range from 20 to more than 2000 days, while the shapes of the light curves may be rather different and variable with each cycle. The amplitudes may be from several hundredths to several magnitudes (usually 1-2 magnitudes in the V filter).

The first representative of this class of reactions was the NaOH (outer electrolyte)+CuCl2 (inner electrolyte) . Later the NaOH+AgNO3 , the CuCl2+K3[Fe(CN)6] , the NaOH+AlCl3 , and the NH3+AgNO3 reactions in several hydrogels have also proved to show similar behavior. Precipitate patterns forming in these reactions are exceptionally rich. Besides the macroscopic shapes like layered structures, helices and cardioids, regular sheets of colloidal precipitate may also emerge with a periodicity even less than 20 micrometers (microscopic patterns).

A primefree sequence found by Herbert Wilf has initial terms :a1 = 20615674205555510, a2 = 3794765361567513 . The proof that every term of this sequence is composite relies on the periodicity of Fibonacci-like number sequences modulo the members of a finite set of primes. For each prime p, the positions in the sequence where the numbers are divisible by p repeat in a periodic pattern, and different primes in the set have overlapping patterns that result in a covering set for the whole sequence.

In 1705, Edmond Halley predicted the periodicity of Halley's Comet, William Herschel discovered Uranus in 1781, and Henry Cavendish measured the gravitational constant and determined the mass of the Earth in 1798. In 1783, John Michell suggested that some objects might be so massive that not even light could escape from them. In 1739, Leonhard Euler solved the ordinary differential equation for a forced harmonic oscillator and noticed the resonance phenomenon. In 1742, Colin Maclaurin discovered his uniformly rotating self-gravitating spheroids.

After a periodic 26-million year cycle was proposed for mass extinctions of life in 1984,Raup, D.M., and Sepkoski, J.J., Jr., 1984, Periodicity of extinctions in the geologic past: Proceedings of the National Academy of Sciences, USA, v. 81, p. 801-805. Rampino and Stothers reported a similar cycle in the ages of impact craters on the Earth.Rampino, M.R., and R.B. Stothers, 1984, Terrestrial mass extinctions, cometary impacts and the Sun's motion perpendicular to the galactic plane, Nature, v.

Northern Afghanistan lies within the broad zone of continuing collision between the Indian Plate and the Eurasian Plate. The area is seismically active, particularly as a result of faulting at just over 200 km depth within the descending slab. Many large events of M ≥ 7 have been observed in the Hindu Kush, all with similar epicenters, with an approximate periodicity of about 10–15 years. These events have reverse fault focal mechanisms, which for the near-vertical slab indicates active extension.

Astronomical Papers of the American Ephemeris (1943) Clemence identified systematic errors in the predictions of Mars' path. The residuals showed a marked periodicity and Clemence concluded that the Fourier series on which the predictions were based was wrong. Clemence set out to derive a new series from scratch using the methods detailed by Hill and Peter Andreas Hansen in the nineteenth century. The calculations were carried out with "a lead pencil, large sheets of computing paper, [and] a hand- operated Millionaire desk calculator".

The Sync-Producer provides the synchronization-signal for the Sync-Consumer. When the Sync-Consumer receive the signal they start carrying out their synchronous tasks. In general, the fixing of the transmission time of synchronous PDO messages coupled with the periodicity of transmission of the Sync Object guarantees that sensor devices may arrange to sample process variables and that actuator devices may apply their actuation in a coordinated fashion. The identifier of the Sync Object is available at index 1005h.

The magnitude, shape, periodicity and frequency of the TLMs will depend on many factors such as the type of light source, the electrical mains-supply frequency, the driver or ballast technology and type of light regulation technology applied (e.g. pulse-width modulation). If the modulation frequency is below the flicker fusion threshold and if the magnitude of the TLM exceeds a certain level, then such TLMs are perceived as flicker. These TLM-properties may vary over time due to aging effects.

Among the comets with short enough periods to have been observed several times in the historical record, Halley's Comet is unique in that it is consistently bright enough to be visible to the naked eye while passing through the inner Solar System. Since the confirmation of the periodicity of Halley's Comet, other periodic comets have been discovered through the use of the telescope. The second comet found to have a periodic orbit was Encke's Comet (with the official designation of 2P/Encke).

The problem of periodicity of four pillars is a problem in calendrical arithmetics but most of fortune tellers are unable to handle the mathematics correctly. Hee for example, proposed that it takes 240 years for a given four-pillar quadruplet to repeat itself. In p. 22, Hee wrote, > . . . because of the numerous possible combinations, it takes 60 years for > the same set of year pillars to repeat itself (by comparison, as set of > month pillars repeats itself after just five years).

McDermott conducted an analysis of all of Emily Dickinson's poetry, their creation dates, biographical materials, and her letters due to speculation that she may have had mental health issues. He published his findings in the American Journal of Psychiatry under the title “Emily Dickinson Revisited: A Study of Periodicity in Her Work”. He came to the conclusion that she may have suffered from bipolar disorder and seasonal changes in her productivity. The article was considered controversial according to author Paul Ruffin.

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.

A Markov chain's state space can be partitioned into communicating classes that describe which states are reachable from each other (in one transition or in many). Each state can be described as transient or recurrent, depending on the probability of the chain ever returning to that state. Markov chains can have properties including periodicity, reversibility and stationarity. A continuous-time Markov chain is like a discrete-time Markov chain, but it moves states continuously through time rather than as discrete time steps.

The PALFA search areas are indicated in light blue. The dots indicate pulsars, this time colored according to their DM. The new PALFA discoveries are indicated by the larger dots. The second pipeline is based on PRESTO, a large suite of pulsar search and analysis software developed by Scott Ransom. It employs a Fourier-domain acceleration search technique, which compensates for the loss of detection sensitivity in a traditional periodicity search due to a rapidly changing frequency of the periodic pulsar signal.

It is a candidate member of the IC 2391 moving group of co-moving stars. This is an aging giant star with a stellar classification of K4III, although Humphreys (1970) found a supergiant class of K3Ib. It is a suspected slow irregular variable of type Lc and its brightness varies from magnitude +4.50 to +4.59 with no periodicity. The star now has 131 times the girth of the Sun, having exhausted the supply of hydrogen at its core then cooled and expanded.

Schematic representation of a self-oscillation as a positive feedback loop. The oscillator V produces a feedback signal B. The controller at R uses this signal to modulate the external power S that acts on the oscillator. If the power is modulated in phase with the oscillator's velocity, a negative damping is established and the oscillation grows until limited by nonlinearities. Self-oscillation is the generation and maintenance of a periodic motion by a source of power that lacks any corresponding periodicity.

The periodicity of the meanders and Natal pulses of the Agulhas is matched by the Agulhas Undercurrent. More research is needed but observations seem to indicate that during a meander event the Agulhas moves first onshore, then offshore, and finally onshore again, first weakening then strengthening 10-15 Sv. At the same time the undercurrent is first squeezed offshore and weakened when the Agulhas moves onshore, then strengthened and forced upward when the Agulhas moves offshore, and finally returns to normal.

Seasonal subseries plots are a graphical tool to visualize and detect seasonality in a time series. Seasonal subseries plots involves the extraction of the seasons from a time series into a subseries. Based on a selected periodicity, it is an alternative plot that emphasizes the seasonal patterns are where the data for each season are collected together in separate mini time plots. Seasonal subseries plots enables the underlying seasonal pattern to be seen clearly, and also shows the changes in seasonality over time.

Hollingworth completed her dissertation under the supervision of the psychologist Edward Thorndike, a major proponent of the variability hypothesis. Though they held conflicting views, Hollingworth thanked him for aiding her. Hollingworth saw it as her duty as a feminist to prove through scientific study that women were equally as capable and intelligent as men in all of their pursuits, even during menstruation. Her dissertation included three studies dealing with functional periodicity among women, two of which were intensive and one which was extensive.

The light curve of DS Andromedae shows a main eclipse when the secondary star passes in front of the primary, and a secondary eclipse when the opposite occurs. This cycle repeats with a periodicity slightly over one day. Since the system is almost exactly edge-on the secondary eclipse is total, and allows the determination of the spectral type of the secondary component. The primary eclipse is annular as the smaller secondary passes in front of the hotter brighter primary.

Sometimes, hypnic jerks are mistaken for another form of movement during sleep. For example, hypnic jerks can be confused with restless leg syndrome, periodic limb movement disorder, hypnagogic foot tremor, rhythmic movement disorder, and hereditary or essential startle syndrome, including the hyperplexia syndrome. But some phenomena can help to distinguish hypnic jerk from these other conditions. For example, the occurrence of hypnic jerk arises only at sleep onset and it happens without any rhythmicity or periodicity of the movements and EMG bursts.

The chart type can also be chosen by the user. An analytically focused system will be used to understand the structure of different terrorist organizations with respect to particular attack types or regions of their activity. By using this system, intelligence analysts will be able to develop hypotheses and then validate them (or not) against the data in the database. In this way, it will be possible to provide certain predictions of international terrorism trends, seasonality, and periodicity of terrorist events.

Its orbit would likely have an eccentricity of 0.24 or less. Like the probably spurious Alpha Centauri Bb, it likely has lakes of molten lava and would be far too close to Alpha Centauri B to harbour life. Around Proxima Centauri, a small spike with a periodicity of 5.15 days was found while revisiting Proxima Centauri b. Were it a planetary companion, it would have to be at most 0.29 Earth masses, but it could also be random noise found in the data.

Havelock Ellis was an English physician and writer born in the eighteen hundreds who studied human sexuality, and is referred to as one of the earliest sexologists. Ellis's work was geared towards human sexual behavior. His major work was a seven-volume publication called Studies in the Psychology of Sex, which related sex to society. Published in 1921, Studies in the Psychology of Sex covered the evolution of modesty, sexual periodicity, auto-erotism, sexual inversion, sexual impulse, sexual selection, and erotic symbolism.

The political rock band Redgum recorded part of Harford's poem "Periodicity" set to music as "Women in Change" on their 1980 album Virgin Ground. In Melbourne, the Victorian Women Lawyers' biennial Lesbia Harford Oration, given by an eminent speaker on an issue of importance for women, is named in her honour. In 1991, the Playbox Theatre Company Melbourne presented Earthly Paradise; a Picture of Lesbia Harford, by the playwright Darryl Emmerson. This play was also published by Currency Press, Sydney.

The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of cyclin-dependent kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin forms a complex with and functions as a regulatory subunit of CDK4 or CDK6, whose activity is required for cell cycle G1/S transition.

See chapter 8, "Escape." The year 1942 consequently marked a turning point in his life; after then he wrote many pieces in 31-equal, which are notable for using the 7th harmonic as a consonant interval (31-equal has a much better approximation of the 7th harmonic than the ubiquitous 12-equal). He also made notable contributions to music theory, such as the Fokker periodicity block. In 1949 he became member of the Royal Netherlands Academy of Arts and Sciences.

DFT-method for identifying protein-coding segments of DNA The three-base periodicity property in the field of Genomics is a property that is characteristic of protein-coding DNA sequences. The existence of this property can be shown by performing Fourier analysis on signals derived from segments of DNA sequences. Because of its predictive power, it has been used as a preliminary indicator in gene prediction. DNA sequences are inherently signals as they are functions of an independent variable, position on the sequence.

The method was first described by Philip Njemanze in 2007, and was referred to as functional transcranial Doppler spectroscopy (fTCDS). fTCDS examines spectral density estimates of periodic processes induced during mental tasks, and hence offers a much more comprehensive picture of changes related to effects of a given mental stimulus. The spectral density estimates would be least affected by artefacts that lack periodicity, and filtering would reduce the effect of noise.Njemanze P.C., Transcranial Doppler spectroscopy for assessment of brain cognitive functions.

The General Catalogue of Variable Stars gives a period of approximately 346 days, but other studies suggest different periods and certainly no strong periodicity. The spectral has been classified as early as G8 and as late as M2, but it isn't clear that there has been actual variation. In the first MK spectral atlas, it was listed M0:Ia. RW Cep was later listed as the standard star for spectral type G8 Ia, then as the standard for K0 0-Ia.

Moreover, mutation of the sites shows that they work in domains, with some phosphorylations serving to lengthen period and others to shorten period. FRQ recruits kinases such as casein kinase 1a (CK-1a) that phosphorylate WCC, although the function of these phosphorylations is unclear as hyperphosphorylated WCC remains active. Eventually, repression is relieved when FRQ becomes so highly phosphorylated that the FFC no longer interacts with the WCC. This process occurs with a periodicity of around 22 hours in constant conditions.

1-2 The infective larvae (L3) actively penetrate the skin through the bite hole and develop into adults in the lymphatic system over a span of 6 months. Adult worms can survive in the lymphatic system for 5–15 years. 3\. The male and female adult worms mate and the females produce an average of 10,000 sheathed eggs (microfilaria) daily The microfilariae enter the blood stream and exhibit nocturnal periodicity and subperiodicity. 4\. Another mosquito takes a blood meal and ingests the microfilariae.

There has been a cycle of ice ages for the past 2.2–2.1 million years (starting before the Quaternary in the late Neogene Period). Note in the graphic on the right the strong 120,000-year periodicity of the cycles, and the striking asymmetry of the curves. This asymmetry is believed to result from complex interactions of feedback mechanisms. It has been observed that ice ages deepen by progressive steps, but the recovery to interglacial conditions occurs in one big step.

HD 130144 (or EK Boötis) is a semiregular variable star in the northern constellation of Boötes. The variation in luminosity has an amplitude of 0.38 in magnitude with no apparent periodicity. This is an X-ray source, and was possibly the first M-type giant star to have a magnetic field directly detected. It is considered to be a single star, although there is nearby companion at an angular separation of 0.2023″ along a position angle of 82.2° (as of 2010.4812).

It is a slow irregular variable star of type Lb, undergoing changes in magnitude over the range 3.57−3.72 with a periodicity of 23.8 d. The measured angular diameter of Tau4 Eridani is . At its estimated distance, this yields a physical size of about 106 times the radius of the Sun. It shines with 1,537 times the luminosity of the Sun from an outer atmosphere at an effective temperature of 3,712 K. This is most likely a binary star system.

It is a transcriptional repressor of genes that require a bHLH protein for their transcription. The protein has a particular type of basic domain that contains a helix interrupting protein that binds to the N-box promoter region rather than the canonical enhancer box (E-box). As a member of the bHLH family, it is a transcriptional repressor that influences cell proliferation and differentiation in embryogenesis. HES1 regulates its own expression via a negative feedback loop, and oscillates with approximately 2-hour periodicity.

The leader of the opposition to my findings was the two-time Nobel Laureate Linus Pauling, the idol of the American Chemical Society and one of the most famous scientists in the world. For years, 'til his last day, he fought against quasi-periodicity in crystals. He was wrong, and after a while, I enjoyed every moment of this scientific battle, knowing that he was wrong." Linus Pauling is noted saying "There is no such thing as quasicrystals, only quasi-scientists.

The regime would only end in 1974, with the Carnation Revolution, that implemented broad democratic changes in the country. Since then, four types of elections are held with different periodicity. The head of state, the President of the Republic, is elected for a five-year term, the Parliament is elected for a four-year term, like the municipal administrations, that since 1985, are also elected for a four-year term. Azores and Madeira elect a regional parliament each four years.

Sanders Sides Series logo since September 1, 2017. Since October 19, 2016, Thomas Sanders has run a YouTube web series called Sanders Sides, co-written with Joan S., in which he discusses personal or existential issues with four main characters, collectively known as the titular "Sanders Sides". Sanders Sides consists of two seasons with a total as of May 2020 of 30 episodes released on a variable periodicity. Season 1 has 17 episodes released from October 19, 2016, to July 19, 2017.

OSO 7 was primarily a solar observatory designed to point a battery of UV and X-ray telescopes at the Sun from a platform mounted on a cylindrical wheel. The detectors for observing cosmic X-ray sources were X-ray proportional counters. The hard X-ray telescope operated over the energy range 7 - 550 keV. OSO 7 performed an X-ray All-sky survey and discovered the 9-day periodicity in Vela X-1 which led to its optical identification as a HMXRB.

This would imply that the 100,000-year periodicity is really an illusion created by averaging together cycles lasting 80,000 and 120,000 years. This theory is consistent with a simple empirical multi-state model proposed by Didier Paillard. Paillard suggests that the late Pleistocene glacial cycles can be seen as jumps between three quasi-stable climate states. The jumps are induced by the orbital forcing, while in the early Pleistocene the 41,000-year glacial cycles resulted from jumps between only two climate states.

When the right-handed super-helix is formed, the glycine residues of each of the monomers is positioned at the center of the super-helix (where the three monomers "touch"). Each left-handed helix is characterized by a complete turn in about 3.3 amino acids. The periodicity induced by the glycines at non- integer spacing results in a super-helix that completes one turn in about 20 amino acids. This (Gly-X-Y)n sequence is repeated 343 times in the type III collagen molecule.

It is still unclear how the transcription-translation feedback loop maintains periodicity and how it is flexible to environmental changes. Since these proteins are essential for the organism to adapt to the environment, understanding the genes are imperative in circadian biology. In cyanobacterium Synechococcus elongates (PCC 7942) kaiA, kaiB, and kaiC are the necessary components that compose the circadian clock. The TTO model of cyanobacteria is questionable due to the finding that phosphorylation of KaiC oscillates regardless of transcription/translation of the kaiBC operon.

This led physicist Richard A. Muller to suggest that these extinctions could be due to a hypothetical companion star to the Sun called Nemesis periodically disrupting the orbits of comets in the Oort cloud, leading to a large increase in the number of comets reaching the inner Solar System where they might hit Earth. Physicist Adrian Melott and paleontologist Richard Bambach have more recently verified the Raup and Sepkoski finding, but argue that it is not consistent with the characteristics expected of a Nemesis-style periodicity.

DQ Herculis systems are interacting binaries in which a low-mass star transfers mass to a highly magnetic white dwarf. The white dwarf spin period is significantly shorter than the binary orbital period and can sometimes be detected as a photometric periodicity. An accretion disk usually forms around the white dwarf, but its innermost regions are magnetically truncated by the white dwarf. Once captured by the white dwarf's magnetic field, the material from the inner disk travels along the magnetic field lines until it accretes.

By making sensitive measurements of the Doppler shift of the spectrum of 55 Cancri A, a 15-day periodicity was detected. The planet was announced in 1996, together with the planet of Tau Boötis and the innermost planet of Upsilon Andromedae. Even when this inner planet, with a mass at least 78% times that of Jupiter was accounted for, the star still showed a drift in its radial velocity. This eventually led to the discovery of the outer planet 55 Cancri d in 2002.

In contrast to meteorology, which focuses on short term weather systems lasting up to a few weeks, climatology studies the frequency and trends of those systems. It studies the periodicity of weather events over years to millennia, as well as changes in long-term average weather patterns, in relation to atmospheric conditions. Climatologists study both the nature of climates – local, regional or global – and the natural or human-induced factors that cause climates to change. Climatology considers the past and can help predict future climate change.

The Z Curve method was first created in 1994 as a way to visually map a DNA or RNA sequence. Different properties of the Z curve, such as its symmetry and periodicity can give unique information on the DNA sequence. The Z curve is generated from a series of nodes, P0, P1,…PN, with the coordinates xn, yn, and zn (n=0,1,2…N, with N being the length of the DNA sequence). The Z curve is created by connecting each of the nodes sequentially.

The reflection takes place in a thin sheet of ionisation around 90 km height. The ionisation patches drift westwards at speeds of few hundred km per hour. There is a weak periodicity noted during the season and typically Es is observed on 1 to 3 successive days and remains absent for a few days to reoccur again. Es do not occur during small hours; the events usually begin at dawn, and there is a peak in the afternoon and a second peak in the evening.

This is controlled by different means in different species, such as through a simple negative feedback loop in zebrafish or in a complicated process in which FGF and Wnt clocks affect the Notch clock, as in chicks and mice. Generally speaking, however, the segmentation clock model is highly evolutionarily conserved. Intrinsic expression of “clock genes” must oscillate with a periodicity equal to the time necessary for one somite to form, for example 30 minutes in zebrafish, 90 minutes in chicks, and 100 minutes in snakes.

Controlling the interface of inorganic-organic hybrid solar cells can increase the efficiency of the cells. This increased efficiency can be achieved by increasing the interfacial surface area between the organic and the inorganic to facilitate charge separation and by controlling the nanoscale lengths and periodicity of each structure so that charges are allowed to separate and move toward the appropriate electrode without recombining. The three main nanoscale structures used are mesoporous inorganic films infused with electron-donating organic, alternatining inorganic-organic lamellar structures, and nanowire structures.

For example, the four-pillar quadruplets for 1984-3-18 and 2044-3-3 are exactly the same (i.e. 甲子-丁卯-辛亥-xx) and they are spaced only by 60 years. But the next iso-quadruplet will reappear only after 360 years (on 2404-4-5). Furthermore, a periodicity of 1800 years is needed to order to match both sexagenary cycle and the Gregorian cycle. For example, 4-3-18, 1980-3-18, and 3964-3-18 share the same four-pillar quadruplet.

In graph theory, a branch of mathematics, a periodic graph with respect to an operator F on graphs is one for which there exists an integer n > 0 such that Fn(G) is isomorphic to G. For example, every graph is periodic with respect to the complementation operator, whereas only complete graphs are periodic with respect to the operator that assigns to each graph the complete graph on the same vertices. Periodicity is one of many properties of graph operators, the central topic in graph dynamics.

AP-1 transcription factor is assembled through the dimerization of a characteristic bZIP domain (basic region leucine zipper) in the Fos and Jun subunits. A typical bZIP domain consists of a “leucine zipper” region, and a “basic region”. The leucine zipper is responsible for dimerization of the Jun and Fos protein subunits. This structural motif twists two alpha helical protein domains into a “coiled coil,” characterized by a periodicity of 3.5 residues per turn and repetitive leucines appearing at every seventh position of the polypeptide chain.

He also contributed drawings to the Swedish periodicity Tidskrift för Jagare och Natur Forskaren which was published in Stockholm by the Svenska Jägareförbundet for hunters and naturalists. In 1833, he became a member of the Stockholm Chamber of Commerce and, two years later, was elected to the Royal Swedish Academy of Arts. After 1836, he lived on the island of Orust in the parish of Morlanda in Bohuslän where he established his residence at Marieberg. In 1845 he married Maria Margareta Bildt (1816-1884).

Regional impacts of warm ENSO episodes (El Niño). In contrast to meteorology, which studies short term weather systems lasting up to a few weeks, climatology studies the frequency and trends of those systems. It studies the periodicity of weather events over years to millennia, as well as changes in long-term average weather patterns, in relation to atmospheric conditions. Climatologists, those who practice climatology, study both the nature of climates – local, regional or global – and the natural or human-induced factors that cause climates to change.

680 When assessing periodicity in the properties of the elements it needs to be borne in mind that the quoted properties of phosphorus tend to be those of its least stable white form rather than, as is the case with all other elements, the most stable form. White phosphorus is the most common, industrially important, and easily reproducible allotrope. For those reasons it is the standard state of the element. Paradoxically, it is also thermodynamically the least stable, as well as the most volatile and reactive form.

Since carriers can tunnel through the barrier regions between the wells, the wave functions of neighboring wells couple together through the thin barrier, therefore, the electronic states in superlattices form delocalized minibands. Solutions for the allowed energy states in superlattices is similar to that for finite quantum wells with a change in the boundary conditions that arise due to the periodicity of the structures. Since the potential is periodic, the system can be mathematically described in a similar way to a one-dimensional crystal lattice.

Raoul Bott used Morse–Bott theory in his original proof of the Bott periodicity theorem. Round functions are examples of Morse–Bott functions, where the critical sets are (disjoint unions of) circles. Morse homology can also be formulated for Morse–Bott functions; the differential in Morse–Bott homology is computed by a spectral sequence. Frederic Bourgeois sketched an approach in the course of his work on a Morse–Bott version of symplectic field theory, but this work was never published due to substantial analytic difficulties.

Large changes in \Delta G, more particularly in the resultant values of \Delta H_A and \Delta H_d provide an insight into EMC Activation's efficacy. The amorphisation of crystalline material at high- pressure conditions "is a rather unusual phenomenon" for the simple reason that "most materials actually experience the reverse transformation from amorphous to crystalline at high-pressure conditions". Amorphisation represents a highly distorted "periodicity" of a material's lattice element, comprising a relatively high Gibbs free energy. Indeed, amorphisation may be compared to a quasi-molten state.

The eclipses have been questioned many times, but special observations are still been made at the times of predicted eclipses. The semi-regular variations have been classified as type SRa, indicating relatively predictable periodicity with some variations in amplitude and light curve shape. These types of variable are considered to be very similar to Mira variables, but with smaller amplitudes. Many long-period variables show long secondary periods, typically ten times longer than the main period, but these changes have not been detected for η Geminorum.

A related description of CTC physics was given in 2001 by Michael Devin, and applied to thermodynamics. The same model with the introduction of a noise term allowing for inexact periodicity, allows the grandfather paradox to be resolved, and clarifies the computational power of a time machine assisted computer. Each time traveling qubit has an associated negentropy, given approximately by the logarithm of the noise of the communication channel. Each use of the time machine can be used to extract as much work from a thermal bath.

It is classified as a semiregular variable star, showing a periodicity of 66.8 days with an amplitude of 0.0202 in visual magnitude. Iota Tucanae is an X-ray source with a luminosity of . It has an estimated 2.2 times the mass of the Sun, and, at the age of 1.69 billion years, it has evolved away from the main sequence, expanding to 11 times the Sun's radius. The star radiates 65 times the solar luminosity from its photosphere at an effective temperature of 5,039 K.

Greenhill et al. (2009) would invoke the presence of a third object to explain orbital period variations with an apparent periodicity of roughly 35 years. The third body could yield a minimum mass 7 times greater than Jupiter and be located 9.5 Astronomical Units away from the cataclysmic variable system, being likely either a massive planetary object or else a very low-mass brown dwarf. It is likely that the apparent change is due to solar-cycle type magnetic activity in the secondary star.

Terhardt rejected the idea of periodicity pitch, because it was not consistent with empirical data on pitch perception, e.g. measurements of the gradual shift of the virtual pitch of a complex tone with a missing fundamental when the partials were gradually shifted. Terhardt instead broke pitch perception into two steps: auditory frequency analysis in the inner ear, and harmonic pitch pattern recognition in the brain. The inner ear effectively performs a running frequency analysis of incoming sounds - otherwise we would not be able to hear out spectral pitches within a complex tone.

There is evidence that geomagnetic excursions may be associated with episodes of rapid short-term climatic cooling during periods of continental glaciation (ice ages). Recent analysis of the geomagnetic reversal frequency, oxygen isotope record, and tectonic plate subduction rate, which are indicators of the changes in the heat flux at the core mantle boundary, climate and plate tectonic activity, shows that all these changes indicate similar rhythms on million years’ timescale in the Cenozoic Era occurring with the common fundamental periodicity of ∼13 Myr during most of the time.

Astronomer Chryssa Kouveliotou of the Universities Space Research Association (USRA) at NASA's Marshall Space Flight Center decided to test the theory that soft gamma repeaters were magnetars. According to the theory, the bursts would cause the object to slow down its rotation. In 1998, she made careful comparisons of the periodicity of soft gamma repeater SGR 1806-20. The period had increased by 0.008 seconds since 1993, and she calculated that this would be explained by a magnetar with a magnetic-field strength of 8×1010 teslas (8×1014 gauss).

Chromium has unique magnetic properties in the sense that chromium is the only elemental solid which shows antiferromagnetic ordering at room temperature (and below). Above 38 °C, its magnetic ordering changes to paramagnetic. The antiferromagnetic properties, which cause the chromium atoms to temporarily ionize and bond with themselves, are present because the body-centric cubic's magnetic properties are disproportionate to the lattice periodicity. This is due to the fact that the magnetic moments at the cube's corners and the cube centers are not equal, but are still antiparallel.

In recent years, geologists have begun to question the laws of uniformitarianism Lyell laid out. There is now clear evidence of catastrophic change caused by volcanic eruptions, large earthquakes, and asteroid impacts. Moreover, there is evidence that certain cataclysmic occurrences that left marks in the geological and fossil records may correspond to the periodicity of the Solar System's 26-million-year cycle of movement around the galactic core of the Milky Way. Even if catastrophes are rare, their magnitude may affect geology more than has been appreciated under Lyell's version of uniformitarianism.

Instead of 'beams' it used a single heavily distorted toroid that was flipped left and right with a periodicity that simulated a morse code letter, the plane of equal field strength in this arrangement being mathematically equal to a line of zero width - a perfect 'beam' from an imperfect, cheaper, and simple radio transmitter. SBA was not automatic, the pilot flew the aircraft at all times. The Beam Approach Beacon System (BABS) is an automatic radar landing system developed in the early 1940s but not used until much later when it replaced the SBA system.

The spectrum varies with a periodicity of 28.9 days, and a helium emission component shows a radial velocity variation that matches the period. The properties indicate it may be a φ Per-like system with a Be star primary and a hot subdwarf companion of type sdO. If this is the case, then the pair have a circular orbit with a period that matches the variability. The close-orbiting pair may have undergone interaction in the past, leaving the subdwarf stripped down and the primary star spinning rapidly.

Slow slip events have been observed to occur in the Cascadia, Japan, and Mexico subduction zones. Unique characteristics of slow slip events include periodicity on timescales of months to years, focus near or down-dip of the locked zone, and along-strike propagation of 5 to 15 km/d. In contrast, a typical earthquake rupture velocity is 70 to 90% of the S-wave velocity, or approximately 3.5 km/s. Because slow slip events occur in subduction zones, their relationship to megathrust earthquakes is of economic, human, and scientific importance.

The largest amplitude atmospheric tides are generated by the periodic heating of the atmosphere by the Sun - the atmosphere is heated during the day and not heated at night. This regular diurnal (daily) cycle in heating generates thermal tides that have periods related to the solar day. It might initially be expected that this diurnal heating would give rise to tides with a period of 24 hours, corresponding to the heating's periodicity. However, observations reveal that large amplitude tides are generated with periods of 24 and 12 hours.

A function with period will repeat on intervals of length , and these intervals are sometimes also referred to as periods of the function. Geometrically, a periodic function can be defined as a function whose graph exhibits translational symmetry, i.e. a function is periodic with period if the graph of is invariant under translation in the -direction by a distance of . This definition of periodicity can be extended to other geometric shapes and patterns, as well as be generalized to higher dimensions, such as periodic tessellations of the plane.

Once they are all fully wound, there is a silence of two to six minutes, at the discretion of the conductor; then, at the conductor's signal, all of the metronomes are started as simultaneously as possible. The performers then leave the stage. As the metronomes wind down one after another and stop, periodicity becomes noticeable in the sound, and individual metronomes can be more clearly distinguished. The piece typically ends with just one metronome ticking alone for a few beats, followed by silence, and then the performers return to the stage .

A rotational lightcurve of Hirayama was obtained at the Menke Observatory in February 2002. It showed a periodicity of hours, during which time the brightness of Hirayama varies by in magnitude (). At the same time, photometric observations by astronomers Roberto Crippa and Federico Manzini gave a rotation period of 22.37 hours and a brightness variation of 0.47 magnitude (). These results supersede an observation from January 2005, by Hiromi and Hiroko Hamanowa at their Hamanowa Astronomical Observatory, Japan, that gave a shorter period of 13.59 hours with an amplitude of 0.57 magnitude.().

The system response is driven by the combination of the two forces that compete/cooperate to make the system switch between the two stable states. The degree of order is related to the amount of periodic function that it shows in the system response. When the periodic force is chosen small enough in order to not make the system response switch, the presence of a non-negligible noise is required for it to happen. When the noise is small very few switches occur, mainly at random with no significant periodicity in the system response.

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.

With careful engineering of the input waveform, light can be made to accelerate along arbitrary trajectories in media that possess discrete or continuous periodicity. In 2018, researchers from Tel-Aviv university measured the cubic phase of Airy beams in an analogous system of surface gravity water-waves. They also managed to accelerate the Airy beam analog, using an external hydrodynamic linear potential and stop the self- accelerating front of the Airy beam. The members of the team associated with the experiment were Georgi Gary Rozenman, Ady Arie and Lev Shemer.

On light microscope examination, these fibres may be distinguished from mature elastic fibers by their failure to stain with aldehyde fuchsin solutions, unless they have been oxidized by potassium permanganate, performic acid or peracetic acid. Under electron microscopy they appear to be composed of microfibrillar units, 7–20 nm in diameter with a periodicity of 12–17 nm. From their morphology, localization and staining properties it seems likely that these fibers are an immature form of elastic tissue. They can be found on the surface of smooth muscles.

Markeas is part of the heritage of the Parisian spectral school, that of a "processual" music, a music more attached to sound than to the note, gradually moving from one state of the material to another; a music involving a dialectic between harmonic and inharmonic, between periodicity and aperiodicity. To this compositional approach, Alexandros Markeas adds a theatrical dimension, allowing him to escape from "pure music". His compositions are marked by the use of multimedia techniques. At some time he was a professor of generative improvisation at the Conservatoire de Paris (CNSMD).

There he observed directly that battles tended to wax and wane with the strength of solar flares and geomagnetic storms during the concurrent height of solar cycle 15. In 1918, Chizhevsky graduated from the Moscow Commercial Institute with a degree in archeology. His Moscow State University Doctorate of Philosophy thesis was "On the periodicity of the world-historical process". (He would later call his view point heliotaraxy or heliotaraxia.) He lectured at Moscow University and Moscow Archaeological Institute on the History of Science in the Ancient World and the History of Archaeological Discovery.

This is compared to the quartan periodicity shown in some other Plasmodium species, such as P. knowlesi which occurs every three days. P. coatneyi, unlike many other species in the genus Plasmodium, is a cause of cerebral malaria. The symptoms of this severe form of malaria include impaired consciousness such as a coma, seizures, brain swelling, intracranial hypertension, and other neurological abnormalities. While the exact mechanism for cerebral malaria is not known, the most commonly used explanation is the sequestration of the protozoan infected erythrocytes in the microvasculature of the brain.

Although models from Pyykkö and Fricke generally place element 172 as the next noble gas, there is no clear consensus on the electron configurations of elements beyond 120 and thus their placement in an extended periodic table. It is now thought that because of relativistic effects, such an extension will feature elements that break the periodicity in known elements, thus posing another hurdle to future periodic table constructs. The discovery of tennessine in 2010 filled the last remaining gap in the seventh period. Any newly discovered elements will thus be placed in an eighth period.

Approximate order in which shells and subshells are arranged by increasing energy according to the Madelung rule The electron configuration or organisation of electrons orbiting neutral atoms shows a recurring pattern or periodicity. The electrons occupy a series of electron shells (numbered 1, 2, and so on). Each shell consists of one or more subshells (named s, p, d, f and g). As atomic number increases, electrons progressively fill these shells and subshells more or less according to the Madelung rule or energy ordering rule, as shown in the diagram.

A tidal bundle sequence can be seen as a variation in bed thickness with a periodicity of 14 days (diurnal) or 28 days (semidiurnal). During the neap tide, when the tidal current strength is weakest, smaller quantities of finer grains are deposited. As the tidal variation grows larger, towards the spring tide, larger quantities of coarser material will be deposited which results in an increasing bed thickness. Bed thickness will be greatest at the spring tide and then decreases as the tidal variation grows smaller, towards the neap tide again and the thinnest beds.

The Frenkel–Kontorova model, also known as the FK model, is a fundamental model of low-dimensional nonlinear physics. The generalized FK model describes a chain of classical particles with nearest neighbor interactions and subjected to a periodic on-site substrate potential. In its original and simplest form the interactions are taken to be harmonic and the potential to be sinusoidal with a periodicity commensurate with the equilibrium distance of the particles. Different choices for the interaction and substrate potentials and inclusion of a driving force may describe a wide range of different physical situations.

Patrick Manson in Xiamen, China (then called Amoy) made two important observations. Firstly he discovered in 1877 that if Culex quinquefasciatus and Aedes aegypti mosquitoes fed on a person with larvae (microfilariae) in the blood, they moulted twice in the insects' abdomen and became larger worms now called infective larvae. Secondly, he found in 1879 that the blood-dwelling forms had a nocturnal periodicity with large numbers appearing in the blood around midnight with minimal numbers in the middle of the day. This coincided with the biting habits of these mosquitoes.

It is unable to degrade leaf litter until it becomes more fragmented and more compacted so that the water-holding capacity increases in the deeper layers of the soil. The magnolia warbler has been noted to line its nests with the fruit bodies' stems. Fruit bodies typically grow in clusters on woody debris. In 1975 American mycologist Martina S. Gilliam investigated the periodicity of spore release in M. rotula and concluded that spore discharge did not follow a regular circadian rhythm, as is typical of agaric and bolete mushrooms, but rather was dependent on rain.

Due to the amino acid sequence and the periodicity of the helices, the leucine side chains are arranged along one face of the α helix and form a hydrophobic surface that modulates dimerization. Hydrophobic residues additional to leucine also form the characteristic 3-4 repeat of α helices involved in “coiled-coil” interactions, and help contribute to the hydrophobic packing that drives dimerization. Together, this hydrophobic surface holds the two subunits together. The basic region of the bZIP domain is just upstream to the leucine zipper, and contains positively charged residues.

Spatial tuning may also be accomplished using a wedge cell. The boundary conditions of the narrower cell squeeze the helical pitch by requiring a particular orientation at the edge, with discrete jumps where the outer cells rotate to the next stable orientation; frequency variation between jumps is continuous. If a defect is introduced into the liquid crystal to disturb the periodicity, a single allowed mode may be created inside of the photonic bandgap, reducing power leeching by spontaneous emission at adjacent frequencies. Defect mode lasing was first predicted in 1987, and was demonstrated in 2003.

All the equilateral pentagons plotted within the area delimited by the condition α ≥ β ≥ δ. Three regions for each of three types of pentagons are shown: stellated, concave and convex The equilateral pentagon as a function of two variables can be plotted in the two-dimensional plane. Each pair of values (α, β) maps to a single point of the plane and also maps to a single pentagon. The periodicity of the values of α and β and the condition α ≥ β ≥ δ permit the size of the mapping to be limited.

A glitch is a sudden increase (around 1 part in 106) in the rotational frequency of a rotation-powered pulsar, which usually decreases steadily due to braking provided by the emission of radiation and high-energy particles. It is unknown whether they are related to the timing noise which all pulsars exhibit. Following a glitch is a period of gradual recovery where the observed periodicity slows to a period close to that observed before the glitch. These gradual recovery periods have been observed to last from days to years.

Without the boundaries of rhythmic structure – a fundamental equal and regular arrangement of pulse repetition, accent, phrase and duration – music would not be possible.Arnold Whittall, in The Oxford Companion to Music, OUP, 2002, Article: Rhythm Modern musical use of terms like meter and measure also reflects the historical importance of music, along with astronomy, in the development of counting, arithmetic and the exact measurement of time and periodicity that is fundamental to physics. The elements of musical form often build strict proportions or hypermetric structures (powers of the numbers 2 and 3).

With the November, 1950, issue of Calico Print, Harold and Lucile Weight, former staff editors at Desert Magazine, became the principal editors. They produced 17 monthly issues in the tabloid form. But the Weights had slipped back into the same deadline-driven routine that drove them from Desert Magazine, forcing them to neglect their efforts to record the stories and history of rapidly disappearing desert pioneers. To cope with that, periodicity of Calico Print was changed to one every two months and the format was changed to that of a slick illustrated digest size magazine.

Spectrum: KO Coefficient ring: The coefficient groups πi(KO) have period 8 in i, given by the sequence Z, Z2, Z2,0, Z, 0, 0, 0, repeated. As a ring, it is generated by a class η in degree 1, a class x4 in degree 4, and an invertible class v14 in degree 8, subject to the relations that 2η = η3 = ηx4 = 0, and x42 = 4v14. KO0(X) is the ring of stable equivalence classes of real vector bundles over X. Bott periodicity implies that the K-groups have period 8.

Spectrum: ku for connective K-theory, ko for connective real K-theory. Coefficient ring: For ku, the coefficient ring is the ring of polynomials over Z on a single class v1 in dimension 2. For ko, the coefficient ring is the quotient of a polynomial ring on three generators, η in dimension 1, x4 in dimension 4, and v14 in dimension 8, the periodicity generator, modulo the relations that 2η = 0, x42 = 4v14, η3 = 0, and ηx = 0\. Roughly speaking, this is K-theory with the negative dimensional parts killed off.

Halley's Comet, named after English astronomer Edmund Halley who first demonstrated its periodicity, returns to the vicinity of the Sun and Earth approximately every 76 years. Since comets are believed to be the most primordial objects in the solar system, their study is of great importance to planetary science. At the time of the 1986 return (technically, "apparition") of the comet, astronomical telescopes and related instrumentation were vastly more sensitive than for any previous apparition. Consequently, the International Halley Watch (IHW) was organized to stimulate, standardize, collect, and archive observations of the comet.

So the sage lets > virtue flow forth from himself, and the four outer wildernesses rejoice in > his benevolent love. (tr. Needham and Wang 1962: 31) The authors compare Aristotle's (c. 350 BCE) Parts of Animals recording that some kinds of sea urchins were fat and good to eat at the full moon, which was one of the oldest biological observations about the lunar periodicity of the reproductive system of echinoderms, especially sea urchins. A third Huainanzi chapter accurately describes the importance of finding a sui burning-mirror's focal point.

As in ABI an additional signal coming from Ultra-small-angle scattering by sub-pixel microstructures of the sample, called dark-field contrast, can also be reconstructed. This method provides high spatial resolution, but also requires long exposure times. An alternative approach is the retrieval of the differential phase by using Moiré fringes. These are created as a superposition of the self-image of G1 and the pattern of G2 by using gratings with the same periodicity and inclining G2 against G1 regarding to the optical axis with a very small angle(<<1).

A pictoral representation of the atomic displacements in a lattice vibration mode. In solid state physics, a surface phonon is the quantum of a lattice vibration mode associated with a solid surface. Similar to the ordinary lattice vibrations in a bulk solid (whose quanta are simply called phonons), the nature of surface vibrations depends on details of periodicity and symmetry of a crystal structure. Surface vibrations are however distinct from the bulk vibrations, as they arise from the abrupt termination of a crystal structure at the surface of a solid.

This is controlled by different means in different species, such as through a simple negative feedback loop in zebrafish or in a complicated process in which FGF and Wnt clocks affect the Notch clock, as in chicks and mice. However, the segmentation clock model is highly evolutionarily conserved. Intrinsic expression of "clock genes" must oscillate with a periodicity equal to the time necessary for one somite to form, for example 30 minutes in zebrafish, 90 minutes in chicks, and 100 minutes in snakes. Gene oscillation in presomitic cells is largely, but not completely, cell-autonomous.

A matter wave clock is a type of clock whose principle of operation makes use of the apparent wavelike properties of matter. Matter waves were first proposed by Louis de Broglie and are sometimes called de Broglie waves. They form a key aspect of wave–particle duality and experiments have since supported the idea. The wave associated with a particle of a given mass, such as an atom, has a defined frequency, and a fixed duration of one cycle from peak to peak that is sometimes called its Compton periodicity.

The periodicity of the bulge corresponded to Pluto's rotation period, which was previously known from Pluto's light curve. This indicated a synchronous orbit, which strongly suggested that the bulge effect was real and not spurious. This resulted in reassessments of Pluto's size, mass, and other physical characteristics because the calculated mass and albedo of the Pluto–Charon system had previously been attributed to Pluto alone. Doubts about Charon's existence were erased when it and Pluto entered a five-year period of mutual eclipses and transits between 1985 and 1990.

It is spectacularly visible how the molecules form a well-ordered array with the periodicity of the nanomesh (3.22 nm). The lower inset shows a region of this substrate with higher resolution, where individual molecules are trapped inside the pores. In addition, the molecules seem to keep their native conformation, what means that their functionality is kept, which is nowadays a challenge in nanoscience. Such systems with wide spacing between individual molecules/clusters and negligible intermolecular interactions might be interesting for applications such as molecular electronics and memory elements, in photochemistry or in optical devices.

The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell division cycle. Cyclins function as activating subunits of enzymatic complex together with cyclin-dependent kinases (CDKs). Different cyclins exhibit distinct expression and degradation patterns that contribute to the temporal coordination of cell cycle events. Cyclin A1 was shown to be expressed in testis and brain, as well as in several leukemic cell lines, and is thought to primarily function in the control of meiosis.

In biomimetic fashion, Chiral Photonics has abstracted the self-assembled structure of the organic CLCs to produce analogous optical devices using tiny lengths of inorganic, twisted fiber. Designing novel microforming towers, the company is able to fabricate devices based on fibers that can be twisted through more than 25,000 revolutions over a one-inch length. These revolutions function as would a fiber Bragg grating. The density of twists per inch, or periodicity, demonstrably results in the light being coupled to the fiber cladding, scattered out of the fiber, or reflected back within the fiber.

The relationship between d-electrons and crystal structure thus becomes apparent. In crystal structure predictions/simulations, the periodicity is usually applied, since the system is imagined as unlimited big in all directions. Starting from a triclinic structure with no further symmetry property assumed, the system may be driven to show some additional symmetry properties by applying Newton's Second Law on particles in the unit cell and a recently developed dynamical equation for the system period vectors (lattice parameters including angles), even if the system is subject to external stress.

Despite the often- applied term cycles, these fluctuations in economic activity do not exhibit uniform or predictable periodicity. The common or popular usage boom-and-bust cycle refers to fluctuations in which the expansion is rapid and the contraction severe. The current view of mainstream economics is that business cycles are essentially the summation of purely random shocks to the economy and thus are not, in fact, cycles, despite appearing to be so. However, certain heterodox schools propose alternative theories suggesting that cycles do in fact exist due to endogenous causes.

Brauner was a student of Robert Bunsen at the University of Heidelberg and later of Henry Roscoe at the University of Manchester. Brauner became lecturer for chemistry at the Charles University of Prague in 1883, assistant professor as of 1890, and full professor as of 1897. During the course of his career, he corresponded frequently with Dmitri Mendeleev, and they influenced each other as models for periodicity of the elements were developed. Brauner retired from the Charles University of Prague in 1925 and died of pneumonia in 1935.

A census is the procedure of systematically acquiring and recording information about the members of a specific given population. It is a regularly occurring and official count of a particular population. The term is used mostly in connection with national population and housing censuses; other common censuses include agriculture, business, and traffic censuses. The United Nations defines the essential features of population and housing censuses as "individual enumeration, universality within a defined territory, simultaneity and defined periodicity", and recommends that population censuses be taken at least every 10 years.

Tender or enlarged inguinal lymph nodes or swelling in the extremities can alert physicians or public health officials to infection. With appropriate laboratory equipment, microscopic examination of differential morphological features of microfilariae in stained blood films can aid diagnosis—in particular the examination of the tail portion, the presence of a sheath, and the size of the cephalic space. Giemsa staining will uniquely stain B. malayi sheath pink. However, finding the microfilariae on blood films can be difficult because of the nocturnal periodicity of some forms of B. malayi.

The inspection of the LEED pattern gives a qualitative picture of the surface periodicity i.e. the size of the surface unit cell and to a certain degree of surface symmetries. However it will give no information about the atomic arrangement within a surface unit cell or the sites of adsorbed atoms. For instance, when the whole superstructure in Figure 7 is shifted such that the atoms adsorb in bridge sites instead of on-top sites the LEED pattern stays the same, although the individual spot intensities may somewhat differ.

It is commonly accepted that an implementation of a Fixed-priority pre-emptive scheduling (FPS) is simpler than a dynamic priority scheduler, like the EDF. However, when comparing the maximum usage of an optimal scheduling under fixed priority (with the priority of each thread given by the Rate-monotonic scheduling), the EDF can reach 100% while the theorical maximum value for Rate-monotonic scheduling is around 69%. Note that EDF does not make any specific assumption on the periodicity of the tasks; hence, it can be used for scheduling periodic as well as aperiodic tasks.

In principle, an atomic structure could be determined from applying X-ray scattering to non-crystalline samples, even to a single molecule. However, crystals offer a much stronger signal due to their periodicity. A crystalline sample is by definition periodic; a crystal is composed of many unit cells repeated indefinitely in three independent directions. Such periodic systems have a Fourier transform that is concentrated at periodically repeating points in reciprocal space known as Bragg peaks; the Bragg peaks correspond to the reflection spots observed in the diffraction image.

A background on the KAM theorem can be found in Henk W. Broer, Mikhail B. Sevryuk (2007) KAM Theory: quasi-periodicity in dynamical systems In: H.W. Broer, B. Hasselblatt and F. Takens (eds.), Handbook of Dynamical Systems Vol. 3, North-Holland, 2010 and a compendium of rigorous mathmetical results, with insight from physics, can be found in Pierre Lochak, (1999) Arnold diffusion; a compendium of remarks and questions In "Hamiltonian Systems with Three or More Degrees of Freedom" (S’Agar´o, 1995), C. Sim´o, ed, NATO ASI Series C: Math. Phys. Sci., Vol.

Sigma Sculptoris, Latinized from σ Sculptoris, is a solitary, white-hued star in the southern constellation of Sculptor. It is faintly visible to the naked eye with an apparent visual magnitude of +5.54. Based upon an annual parallax shift of 14.04 mas as seen from Earth, it is located about 232 light years from the Sun. This is an A-type subgiant with a stellar classification of A1/A2 IV. It is a suspected Ap star and is classified as an Alpha2 Canum Venaticorum variable with a periodicity of 2.37 days.

Disallowed bands of wavelengths are called photonic band gaps. This gives rise to distinct optical phenomena, such as inhibition of spontaneous emission, high-reflecting omni-directional mirrors, and low-loss- waveguiding. Intuitively, the bandgap of photonic crystals can be understood to arise from the destructive interference of multiple reflections of light propagating in the crystal at the interfaces of the high- and low- dielectric constant regions, akin to the bandgaps of electrons in solids. The periodicity of the photonic crystal structure must be around half the wavelength of the electromagnetic waves to be diffracted.

Total internal reflection confines light to the slab, and allows photonic crystal effects, such as engineering photonic dispersion in the slab. Researchers around the world are looking for ways to use photonic crystal slabs in integrated computer chips, to improve optical processing of communications—both on-chip and between chips. Autocloning fabrication technique, proposed for infrared and visible range photonic crystals by Sato et al. in 2002, utilizes electron-beam lithography and dry etching: lithographically-formed layers of periodic grooves are stacked by regulated sputter deposition and etching, resulting in "stationary corrugations" and periodicity.

In mathematics, an almost periodic function is, loosely speaking, a function of a real number that is periodic to within any desired level of accuracy, given suitably long, well-distributed "almost-periods". The concept was first studied by Harald Bohr and later generalized by Vyacheslav Stepanov, Hermann Weyl and Abram Samoilovitch Besicovitch, amongst others. There is also a notion of almost periodic functions on locally compact abelian groups, first studied by John von Neumann. Almost periodicity is a property of dynamical systems that appear to retrace their paths through phase space, but not exactly.

In June 2020, astronomers from Jodrell Bank Observatory reported that FRB 121102 exhibits the same radio burst behavior ("radio bursts observed in a window lasting approximately 90 days followed by a silent period of 67 days") every 157 days, suggesting that the bursts may be associated with "the orbital motion of a massive star, a neutron star or a black hole". Subsequent studies by FAST of further activity, consisting of 12 bursts within two hours observed on 17 August 2020, supports an updated refined periodicity between active periods of 156.1 days.

No calculation can predict chemical reactions. His book Number Theory and the Periodicity of Matter (co-authored with Demetrius C. Levendis) references the work of Peter Plichta. In it they try to replace modern quantum physics with elementary number theory, but unlike Plichta they do not question the general theory of relativity: > It is a myth that chemistry derives from quantum theory. More fundamental > than both is the periodic table that reduces the properties of matter to a > number basis, which is revealed only peripherally in the differential > equations of quantum theory.

In condensed matter physics, the Fermi surface is the surface in reciprocal space which separates occupied from unoccupied electron states at zero temperature. The shape of the Fermi surface is derived from the periodicity and symmetry of the crystalline lattice and from the occupation of electronic energy bands. The existence of a Fermi surface is a direct consequence of the Pauli exclusion principle, which allows a maximum of one electron per quantum state.N. Ashcroft and N.D. Mermin, Solid-State Physics, W.A. Harrison, Electronic Structure and the Properties of Solids, VRML Fermi Surface DatabaseJ.

Both X-rays and high-energy neutrons are used to probe the structure and periodicity of biological structures including bilayers because they can be tuned to interact with matter at the relevant (angstrom-nm) length scales. Often, these two classes of experiment provide complementary information because each has different advantages and disadvantages. X-rays interact only weakly with water, so bulk samples can be probed with relatively easy sample preparation. This is one of the reasons that x-ray scattering was the technique first used to systematically study inter-bilayer spacing.

According to Zhu & Qian (2009) a third low-mass object of stellar nature could be responsible of orbital period variations observed for WZ Cep with a periodicity of roughly 32 years. Such a companion would yield a minimum mass of 0.17 Solar masses and be located 26.6 Astronomical Units (nearly the same orbital separation of Neptune in Solar System) from the eclipsing binary. The star could likely turn out a Proxima Centauri-analog, with inferred luminosity 3.7 percent that of Sun and 20 percent of its radius, according to mass-radius relationship.

The Little–Parks effect was discovered in 1962 by William A. Little and Roland D. Parks in experiments with empty and thin-walled superconducting cylinders subjected to a parallel magnetic field.W. A. Little and R. D. Parks, “Observation of Quantum Periodicity in the Transition Temperature of a Superconducting Cylinder”, Physical Review Letters 9, 9 (1962), doi:10.1103/PhysRevLett.9.9 It was one of the first experiments that indicate the importance of Cooper-pairing principle in BCS theory. The essence of Little–Parks (LP) effect is slight suppression of the superconductivity by persistent current.

In 1997, the discovery of a 51 Pegasi-like planet orbiting 55 Cancri A was announced, together with the planet of Tau Boötis and the inner planet of Upsilon Andromedae. The planet was discovered by measuring the star's radial velocity, which showed a periodicity of around 14.7 days corresponding to a planet at least 78% of the mass of Jupiter. These radial velocity measurements still showed a drift unaccounted-for by this planet, which could be explained by the gravitational influence of a more distant object. In 1998 the discovery of a possible dust disk around 55 Cancri A was announced.

Adsorbed species on single crystal surfaces are frequently found to exhibit long-range ordering; that is to say that the adsorbed species form a well-defined overlayer structure. Each particular structure may only exist over a limited coverage range of the adsorbate, and in some adsorbate/substrate systems a whole progression of adsorbate structure are formed as the surface coverage is gradually increased. The periodicity of the overlayer (which often is larger than that of the substrate unit cell) can be determined by low-energy electron diffraction (LEED), because there will be additional diffraction beams associated with the overlayer.

Temporal light modulation disturbances may arise from fluctuations of the light intensity of lighting equipment. Light emitted from lighting equipment such as luminaires and lamps may vary in strength as function of time, either intentionally or unintentionally (Figure 1). Generally, the light output of lighting equipment has unintentional residual light level modulations due to the lighting equipment itself. The magnitude, shape, periodicity and frequency of the TLM depends on many factors such as the type of light source, the electrical mains-supply frequency, the driver or ballast technology and type of light regulation technology applied (e.g.

Graph showing average temperatures during the Mesoproterozoic. Blue line uses CO2 concentration 5 times modern day, red line 10 times, and red dot shows average temperature range at the tropics There is little evidence of significant climatic variability during this time period. Climate was likely not primarily dictated by solar luminosity because the Sun was 5–18% less luminous than it is today, but there is no evidence that Earth's climate was significantly cooler. In fact, the Boring Billion seems to lack any evidence of prolonged glaciations, which can be observed at regular periodicity in other parts of Earth's geologic history.

Uncertainty around age estimates from fin ray annulus may account for any disparity. Spawning periodicity is thought to be 2 to 4 years for females and 1 to 2 years for males. Behavior during spawning is not well known, but it is known that they are communal broadcast spawners, where a female's eggs are fertilized by many males. When ready to spawn, white sturgeon choose a variety of substrates dependent on the river system, spawning on gravel or rocky substrate in moderate to fast currents, with observed depths of , and water velocities at the bottom on a range of 0.6-2.4 m/sec.

In the early 19th century, several comets were seen; in particular, Halley's Comet returned in 1835, and there was interest in Encke's Comet, whose periodicity had recently been calculated; it appeared in 1838, and its return was expected in 1842. All this aroused people's interest; comets were traditionally associated with prophesies of the end of the world. Donald Olson and Shaun B. Ford at Texas State University speculate that Lexell's Comet and Biela's Comet inspired the story. Biela's Comet was reputed to have caused a "comet panic" in 1832, after a miscalculation of the comet's trajectory suggested collision with Earth.

The structural geometry of silicon and oxygen in glass is similar to that in quartz and most other crystalline forms of silicon and oxygen with silicon surrounded by regular tetrahedra of oxygen centers. The difference between the glass and crystalline forms arises from the connectivity of the tetrahedral units: Although there is no long range periodicity in the glassy network ordering remains at length scales well beyond the SiO bond length. One example of this ordering is the preference to form rings of 6-tetrahedra. The majority of optical fibers for telecommunication are also made from silica.

Using Edmund Halley's records of comet sightings, however, William Whiston in 1711 wrote that the Great Comet of 1680 had a periodicity of 574 years and was responsible for the worldwide flood in the Book of Genesis, by pouring water on Earth. His announcement revived for another century fear of comets, now as direct threats to the world instead of signs of disasters. Spectroscopic analysis in 1910 found the toxic gas cyanogen in the tail of Halley's Comet, causing panicked buying of gas masks and quack "anti-comet pills" and "anti- comet umbrellas" by the public.

However, DFT modeling of complex, random alloys has its own challenges, as the method requires defining a fixed-size cell, which can introduce non-random periodicity. This is commonly overcome using the method of "special quasirandom structures," designed to most closely approximate the radial distribution function of a random system, combined with the Vienna Ab-initio Simulation Package. Using this method, it has been shown that results of a 4-component equiatomic alloy begins to converge with a cell as small as 24 atoms. The exact muffin-tin orbital method with the coherent potential approximation has also been employed to model HEAs.

However, since almost all numbers in are irrational, almost all initial conditions of the bit-shift map lead to the non-periodicity of chaos. This is one way to see that the logistic map is chaotic for almost all initial conditions. The number of cycles of (minimal) length for the logistic map with (tent map with ) is a known integer sequence : 2, 1, 2, 3, 6, 9, 18, 30, 56, 99, 186, 335, 630, 1161…. This tells us that the logistic map with has 2 fixed points, 1 cycle of length 2, 2 cycles of length 3 and so on.

The more distant component, Epsilon Lupi B, has a mass of about 7.64 times the Sun. The combined stellar classification of the system is B2 IV-V, while the individual components may have spectral classes of B3 IV, B3 V, and A5 V, in order of decreasing mass. The inner A-a pair appear to have their rate of spin synchronized with their orbit, so that the same face of each star always faces its partner. The secondary, Epsilon Lupi a, shows regular variation in luminosity of the type that occurs with Beta Cephei variables, at a periodicity of 10.36 cycles per day.

Hence, once the distance to the SMC was known with greater accuracy, Cepheid variables could be used as a standard candle for measuring the distances to other galaxies. Using this period-luminosity relation, in 1913 the distance to the SMC was first estimated by Ejnar Hertzsprung. First he measured thirteen nearby cepheid variables to find the absolute magnitude of a variable with a period of one day. By comparing this to the periodicity of the variables as measured by Leavitt, he was able to estimate a distance of 10,000 parsecs (30,000 light years) between the Sun and the SMC.

The primary, component A, is an evolved K-type giant star with a stellar classification of F3 III. However, Houk and Swift (1999) listed a classification of F0 V, which would match an F-type main sequence star. It displays an infrared excess at a wavelength of 70 μm and thus is a candidate host of an orbiting debris disk. The common proper motion companion, component B, is a G-type main sequence star with a classification of G3 V. It is a BY Draconis variable with a periodicity of 8.92 days and a variable star designation of EZ Cet.

Moreover, the majority of research has focused on the passive properties of artificial periodic THz transmission, as determined by the patterning of the metamaterial elements e.g., the effects of the size and shape of inclusions, metal film thickness, hole geometry, periodicity, etc. It has been shown that the resonance can also be affected by depositing a dielectric layer on the metal hole arrays and by doping a semiconductor substrate, both of which result in significant shifting of the resonance frequency. However, little work has focused on the "active" manipulation of the extraordinary optical transmission though it is essential to realize many applications.

The apparent magnitude of TX Piscium varies between +4.9 and +5.5 and it is classified as a slow irregular variable. Photometry has shown some periodicity in the brightness of 224 days, and some spectral variation over 450 days, suggesting the star is not entirely irregular. The star apparently lies on the period-luminosity relation corresponding to fundamental mode pulsations, unusual for a low-amplitude semi-regular or irregular variable which usually pulsate in an overtone. The angular diameter has been measured at around 10 mas, although this varies depending on the observed wavelength and the atmosphere appears to be highly asymmetric.

Although the effects of the Dansgaard–Oeschger events are largely constrained to ice cores taken from Greenland, there is evidence to suggest that D-O events have been globally synchronous. A spectral analysis of the American GISP2 isotope record showed a peak of [18O:16O] abundance around 1500 years. This was proposed by Schulz (2002) to be a regular periodicity of 1470 years. This finding was supported by Rahmstorf (2003); if only the most recent 50,000 years from the GISP2 core are examined, the variation of the trigger is ±12% (±2% in the 5 most recent events, whose dates are probably most precise).

A quantum diffractor has an essentially quantum character. It was first conceived of in 1923 by William Duane, in the days of the old quantum theory, to account for diffraction of X-rays as particles according to Einstein's new conception of them, as carriers of quanta of momentum. The diffractor was imagined as exhibiting quantum transfer of translational momentum, in close analogy with transfer of angular momentum in integer multiples of Planck's constant. The quantum of translational momentum was proposed to be explained by global quantum physical properties of the diffractor arising from its spatial periodicity.

Although a periodicity of 73.26 days has been observed in the star's radial velocity, it seems likely to be bound more to stellar activity than to a planetary object in close orbit. No substellar companion has been detected so far around Pi³ Orionis and the McDonald Observatory team has set limits to the presence of one or more planets with masses between 0.84 and 46.7 Jupiter masses and average separations spanning between 0.05 and 5.2 astronomical units. Thus, so far it appears that planets could easily orbit in the habitable zone without any complications caused by a gravitationally perturbing body.

Jeremiah Horrocks, William Crabtree, and the Lancashire observations of the transit of Venus of 1639, Allan Chapman 2004 Cambridge University Press He also used his observations to expand contemporary star maps. He aided in observationally proving Isaac Newton's laws of motion, and funded the publication of Newton's influential Philosophiæ Naturalis Principia Mathematica. From his September 1682 observations, he used the laws of motion to compute the periodicity of Halley's Comet in his 1705 Synopsis of the Astronomy of Comets. It was named after him upon its predicted return in 1758, which he did not live to see.

Zabusky and Kruskal argued that it was the fact that soliton solutions of the KdV equation can pass through one another without affecting the asymptotic shapes that explained the quasi-periodicity of the waves in the FPUT experiment. In short, thermalization could not occur because of a certain "soliton symmetry" in the system, which broke ergodicity. A similar set of manipulations (and approximations) lead to the Toda lattice, which is also famous for being a completely integrable system. It, too, has soliton solutions, the Lax pairs, and so also can be used to argue for the lack of ergodicity in the FPUT model.

Circadian rhythms have been documented for centuries. For example, French astronomer Jean-Jacques d’Ortous de Mairan noted the periodic 24-hour movement of Mimosa plant leaves as early as 1729. However, science has only recently begun to uncover the cellular mechanisms responsible for driving observed circadian rhythms. The cellular basis of circadian rhythms is supported by the fact that rhythms have been observed in single-celled organisms Beginning in the 1970s, experiments conducted by Ron Konopka and colleagues, in which forward genetic methods were used to induce mutation, revealed that Drosophila melanogaster specimens with altered period (Per) genes also demonstrated altered periodicity.

While more closely related to Plasmodium vivax than to P. falciparum, P. coatneyi has been used as a model organism for P. falciparum in a model organism for humans, rhesus macaques. This is due to the several similarities that P. coatneyi and P. falciparum have in common. These similarities includes having a tertiary periodicity, causing cerebral malaria, causing knob protrusion on the surface of infected red blood cells, and adhering the red blood cells to the same sites of the endothelium. Because of these similarities, experiments have been run to further research the mechanism(s) for cerebral malaria.

One of the first methods ever used to analyze DFC was pattern analysis of fMRI images to show that there are patterns of activation in spatially separated brain regions that tend to have synchronous activity. It has become clear that there is a spatial and temporal periodicity in the brain that probably reflects some of the constant processes of the brain. Repeating patterns of network information have been suggested to account for 25–50% of the variance in fMRI BOLD data. These patterns of activity have primarily been seen in rats as a propagating wave of synchronized activity along the cortex.

In 1984, paleontologists David Raup and Jack Sepkoski published a paper claiming that they had identified a statistical periodicity in extinction rates over the last 250 million years using various forms of time series analysis. They focused on the extinction intensity of fossil families of marine vertebrates, invertebrates, and protozoans, identifying 12 extinction events over the time period in question. The average time interval between extinction events was determined as 26 million years. At the time, two of the identified extinction events (Cretaceous–Paleogene and Eocene–Oligocene) could be shown to coincide with large impact events.

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%.

None of the proposals was accepted immediately, and many contemporary chemists found it too abstract to have any meaningful value. Of those chemists that proposed their categorizations, Mendeleev stood out as he strove to back his work and promote his vision of periodicity. In contrast, Meyer did not promote his work very actively, and Newlands did not make a single attempt to gain recognition abroad. Both Mendeleev and Meyer created their respective tables for their pedagogical needs; the difference between their tables is well explained by the fact that the two chemists sought to use a formalized system to solve different problems.

This provided enough traffic based on the identical settings (6 messages with indicator 59173) to have a chance of finding some periodicity that would reveal the inner workings of the twenties cipher. On 20 September 1940 at about 2 pm Genevieve Grotjan, carrying a set of work sheets walked up to a group of men engrossed in conversation and politely attempted to get Frank Rowlett's attention. She had found evidence of cycles in the twenties cipher. Celebration ensued at this first break in the 20s cipher and it soon enabled a replica machine to be built.

To classify semiconductors and semimetals, the energies of their filled and empty bands must be plotted against the crystal momentum of conduction electrons. According to the Bloch theorem the conduction of electrons depends on the periodicity of the crystal lattice in different directions. In a semimetal, the bottom of the conduction band is typically situated in a different part of momentum space (at a different k-vector) than the top of the valence band. One could say that a semimetal is a semiconductor with a negative indirect bandgap, although they are seldom described in those terms.

After the discovery of pulsars in 1967, searches for more pulsars relied on two key characteristics of pulsar pulses in order to distinguish pulsars from noise caused by terrestrial radio signals. The first is the periodic nature of pulsars. By performing periodicity searches through data, "pulsars are detected with much higher signal-to-noise ratios" than when simply looking for individual pulses. The second defining characteristic of pulsar signals is the dispersion in frequency of an individual pulse, due to the frequency dependence of the phase velocity of an electromagnetic wave that travels through an ionized medium.

59P/Kearns–Kwee is a periodic comet in the Solar System with a current orbital period of 9.52 years. It was discovered by E. Kearns and Kiem King Kwee on a photographic plate taken on 17 August 1963 during a search for the lost comet 55P/Tempel–Tuttle and confirmed by Elizabeth Roemer at the US Naval Observatory Flagstaff Station, Arizona. She estimated its brightness at a faint magnitude of 16. The perihelion was initially calculated as 28 October 1963 and the periodicity as 8.48 years, but calculations based on further observations revised the data to 7 December and 8.95 years.

Textual systems include IDENTIFICATION, by which the identities of people, things and places are introduced and tracked through discourse, and PERIODICITY, which organises discourse in waves of information at the scales of the text, phase (paragraph) and clause. In developing discourse semantic theory, Martin was particularly influenced by H.A. Gleason's stratificational linguistics, Ruqaiya Hasan's text semantics, and Michael Halliday's systemic functional linguistics. The genre theory of the Sydney School describes genres as 'staged, goal-oriented social processes'. In functional linguistics terms they are defined as a recurrent configuration of meanings, that enact the social practices of a culture.

The two stars eclipse each other during their orbit, but they have an elongated shape so they show a constant variation instead of discrete eclipses. Anyway, a periodicity can be seen clearly, but it changes with time; the period shows a long-term trend and a periodic modulation of 7,000 days. The effects responsible for this behaviour could be a third body in the system, magnetic interaction between two stars, mass transfer from one star to the another, mass loss of the system, and recently even an internal mechanism in the touching envelopes have been proposed.

Klaproth was able to precipitate a yellow compound (likely sodium diuranate) by dissolving pitchblende in nitric acid and neutralizing the solution with sodium hydroxide. He then reduced the obtained yellow powder with charcoal, and extracted a black substance that he mistook for metal. Only 60 years later, the French scientist Eugène-Melchior Péligot identified it as uranium oxide. He also isolated the first sample of uranium metal by heating uranium tetrachloride with metallic potassium. The atomic mass of uranium was then calculated as 120, but Dmitri Mendeleev in 1872 corrected it to 240 using his periodicity laws.

For example, lighting equipment connected to a single-phase mains supply will typically have residual TLMs of twice the mains frequency, either at 100 or 120 Hz (depending on country). The magnitude, shape, periodicity and frequency of the TLMs will depend on many factors such as the type of light source, the electrical mains-supply frequency, the driver or ballast technology and type of light regulation technology applied (e.g. pulse-width modulation). If the modulation frequency is below the flicker fusion threshold and if the magnitude of the TLM exceeds a certain level, then such TLMs are perceived as flicker.

Another characteristic of ducks is that they are migratory birds coming to Korea in autumn. Migratory birds appear and disappear on a regular basis and it was believed that ducks travel to the world beyond the Earth and act as a messenger between the physical world and the realm of the spirits. In agriculture, this periodicity might be associated with the cycle of monsoon which brings rain. Also, the fact that ducks are fertile species and lay bigger eggs than chickens do would be a good reason for ducks to be an idolized object representing abundance.

Type 1 Second-degree AV block, also known as Mobitz I or Wenckebach periodicity, is almost always a disease of the AV node. Wenckebach published a paper in 1906 on progressively lengthening PR intervals that was later classified as Type I in Mobitz's 1924 paper. Thus, both "Mobitz type I" and "Wenckebach block" refer to the same pattern and pathophysiology. In Wenckebach's 1906 paper, his original observations were from increasing delay in contraction of the atria & ventricles that shortened after a brief pause and this was later observed on ECG after Einthoven's invention in 1901 that became the electrocardiogram (ECG).

An alternative or variation of the contourlet transform was proposed by Lu and Do in 2006. This new proposed method was intended as a remedy to fix non-localized basis images in frequency. The issue with the original contourlet transform was that when the contourlet transform was used with imperfect filter bank filters aliasing occurs and the frequency domain resolution is affected. There are two contributing factors to the aliasing, the first is the periodicity of 2-D frequency spectra and the second is an inherent flaw in the critical sampling of the directional filter banks.

In 1775, Thomas Jefferson recorded in his "Garden Book" Brood II's 17-year periodicity, writing that an acquaintance remembered "great locust years" in 1724 and 1741, that he and others recalled another such year in 1758 and that the insects had again emerged from the ground at Monticello in 1775. He noted that the females lay their eggs in the small twigs of trees while above ground. Brood II last appeared in the late spring and summer of 2013, and will emerge again in 2030 and 2047. The 4-centimeter long (1.5 in) black insects do not sting or bite.

A OTDOA procedure works as follows: The ESMLC requests through the LPP layer an OTDOA measurement: a set of RSTD (Reference Signal Time Difference) measurements from the UE. Together with this request the UE receives assistance data. This assistance data, provides a list of cells (enodeBs), with their PRS (Positioning Reference Signal) parameters, including BW, periodicity etc. The UE then proceeds to perform these measurements during a given period of time (typically up to 8 or 16 periods of the PRS signals). These measurements consist on estimating the exact time offsets between the PRS from different cells.

1, 1999; Ernesto Screpanti, The Fundamental Institutions of Capitalism, Routledge, London 2001. In dynamic analysis Screpanti criticized the so-called “laws of movement of capitalist development” as formulated by Marx, because of their deterministic implications as philosophies of history and the analytic limitations of some of their assumptions. He put forward a theory of development as an evolutionary process of a cyclical kind, coupling long and short run periodicity factors, both of which are determined by the dynamics of class conflict and income distribution.Ernesto Screpanti, "Long Economic Cycles and Recurring Proletarian Insurgencies", "Review of the F.Braudel Center", New York State University, VII, n.

First, people and firms will act to maximize their self- interested goals. Second, markets tend towards an equilibrium of prices, where demand matches supply. He extended the mathematics to describe equilibrating behavior of economic systems, including that of the then new macroeconomic theory of John Maynard Keynes. Whilst Richard Cantillon had imitated Isaac Newton's mechanical physics of inertia and gravity in competition and the market, the physiocrats had copied the body's blood system into circular flow of income models, William Jevons had found growth cycles to match the periodicity of sunspots, Samuelson adapted thermodynamics formulae to economic theory.

From the knowledge of the reciprocal lattice models for the real space lattice can be constructed and the surface can be characterized at least qualitatively in terms of the surface periodicity and the point group. Figure 7 shows a model of an unreconstructed (100) face of a simple cubic crystal and the expected LEED pattern. Since these patterns can be inferred from the crystal structure of the bulk crystal, known from other more quantitative diffraction techniques, LEED is more interesting in the cases where the surface layers of a material reconstruct, or where surface adsorbates form their own superstructures.

The cat gap is a period in the fossil record of approximately 25 to 18.5 million years ago in which there are few fossils of cats or cat-like species found in North America. The cause of the "cat gap" is disputed, but may have been caused by changes in the climate (global cooling), changes in the habitat and environmental ecosystem, the increasingly hypercarnivorous trend of the cats (especially the nimravids), volcanic activity, evolutionary changes in dental morphology of the Canidae species present in North America, or a periodicity of extinctions called van der Hammen cycles.

An important application area for generalized transforms involves systems in which high frequency resolution is crucial. For example, darkfield electron optical transforms intermediate between direct and reciprocal space have been widely used in the harmonic analysis of atom clustering, i.e. in the study of crystals and crystal defects.P. Hirsch, A. Howie, R. Nicholson, D. W. Pashley and M. J. Whelan (1965/1977) Electron microscopy of thin crystals (Butterworths, London/Krieger, Malabar FLA) Now that transmission electron microscopes are capable of providing digital images with picometer-scale information on atomic periodicity in nanostructure of all sorts, the range of pattern recognitionP.

300px The North Atlantic Oscillation (NAO) is a weather phenomenon in the North Atlantic Ocean of fluctuations in the difference of atmospheric pressure at sea level (SLP) between the Icelandic Low and the Azores High. Through fluctuations in the strength of the Icelandic low and the Azores high, it controls the strength and direction of westerly winds and location of storm tracks across the North Atlantic. It is part of the Arctic oscillation, and varies over time with no particular periodicity. The NAO was discovered through several studies in the late 19th and early 20th centuries.

Knots can be tied in the core of such a vortex, leading to the hypothesis that each chemical element corresponds to a different kind of knot. The simple toroidal vortex, represented by the circular "unknot" 01, was thought to represent hydrogen. Many elements had yet to be discovered, so the next knot, the trefoil knot 31, was thought to represent carbon. However, as more elements were discovered and the periodicity of their characteristics established in the periodic table of the elements, it became clear that this could not be explained by any rational classification of knots.

On November 6, 2009, a planetary companion around primary star Gamma1 Leonis has been announced. Moreover, radial velocity variations would also hint two strong signals at 8.5 and 1340 days. The former periodicity is likely due to stellar pulsation, whereas the latter could be indicative of the presence of an additional planetary companion with 2.14 Jupiter masses, moderate eccentricity (e=0.13) and located at 2.6 Astronomical Units away from the giant star. Nevertheless, the nature of such a signal is still unclear and further investigations are needed to confirm or rule out an additional substellar companion.

Flood beds on the Sanpoil arm of glacial Lake Columbia show episodic flood deposits as well as deposit grading and rhythmical repetition. Since Glacial Lake Columbia remained filled between Missoula floods, annual deposits (varves) can be observed between the Missoula flood deposits, they help to establish the periodicity of these major floods. The flood deposits can be distinguished from annually-deposited varves by both their thickness and the presence of materials foreign to the immediate drainage. Atwater reports from 35 to 55 annual varves between flood deposits in Lake Columbia, supporting a period of 35 to 55 years between ice dam failures.

The 3D model of the element to be inspected can be projected in the image plane for more complex shapes. The evaluation is based on indices such as the uniformity of segmented regions, convexity of their forms, or periodicity of the image pixels' intensity. The feature extraction using speeded up robust features (SURF) is also able to perform the inspection of certain elements having two possible states, such as pitot probes or static ports being covered or not covered. A pairing is performed between images of the element to be inspected in different states and that present on the scene.

The star is typically radiating 515 times the Sun's luminosity from its photosphere at an effective temperature of 23,014 K. The variability of this star was announced in 1937, at the 58th Meeting of the American Astronomical Society by Canadian astronomer, Robert Methven Petrie. It is a Beta Cephei variable that ranges between magnitudes 6.44 and 6.68 over a period of 4.8 hours. For unknown reasons, the periodicity of the star has undergone sudden changes, followed by long periods of stability. BW Vul is one of the most extreme β Cephei stars in terms of variability of light and radial velocity.

Poisson's ratio defines how a material expands (or contracts) transversely when being compressed longitudinally. While most natural materials have a positive Poisson's ratio (coinciding with our intuitive idea that by compressing a material it must expand in the orthogonal direction), a family of extreme materials known as auxetic materials can exhibit Poisson's ratios below zero. Examples of these can be found in nature, or fabricated, and often consist of a low-volume microstructure that grants the extreme properties to the bulk material. Simple designs of composites possessing negative Poisson's ratio (inverted hexagonal periodicity cell) were published in 1985.

In 1913, Henry Moseley determined that periodicity depends on the atomic number rather than atomic weight. Lothar Meyer presented his table several months after Mendeleev, but opposed his Periodic law. Initially, no theoretical explanation for the Periodic Law was available and it was used only as an empirical principle, but, with the development of the quantum mechanics, it became possible to understand the theoretical basis for the Periodic Law. The periodic recurrence of elements with similar physical and chemical properties, when the elements are listed in order of increasing atomic number, results directly from the periodic recurrence of similar electronic configurations in the outer shells of respective atoms.

Frank Yates in 1932 published his version called interaction algorithm, which provided efficient computation of Hadamard and Walsh transforms. Yates' algorithm is still used in the field of statistical design and analysis of experiments. In 1942, G. C. Danielson and Cornelius Lanczos published their version to compute DFT for x-ray crystallography, a field where calculation of Fourier transforms presented a formidable bottleneck. While many methods in the past had focused on reducing the constant factor for O\left(N^2\right) computation by taking advantage of "symmetries", Danielson and Lanczos realized that one could use the "periodicity" and apply a "doubling trick" to get O(N \log N) runtime.

Device applications of this work include photon detectors and sources, as well as quantum information processing. He has published extensively on these topics in scientific journals. He has shown that the properties of quasicrystals depend critically on the way in which their quasi- periodicity is arranged. He is a research fellow of the American Physical Society (APS), fellow of the Institute of Physics(F InstP), a Chartered Physicist (CPhys) both of the UK, a fellow of the New York Academy of Sciences, a visiting fellow of Trinity College, Cambridge University in 2007–2008 and a Kavli Institute of Theoretical Physics Scholar at the University of California in Santa Barbara.

For example, all the elements of group 2 have an electron configuration of [E] ns (where [E] is an inert gas configuration), and have notable similarities in their chemical properties. In general, the periodicity of the periodic table in terms of periodic table blocks is clearly due to the number of electrons (2, 6, 10, 14...) needed to fill s, p, d, and f subshells. The outermost electron shell is often referred to as the "valence shell" and (to a first approximation) determines the chemical properties. It should be remembered that the similarities in the chemical properties were remarked on more than a century before the idea of electron configuration.

Even when both of the two planets were accounted for, there was still a periodicity at around 43 days. However, this period is close to the rotation period of 55 Cancri A, which led to the possibility that the 43-day period was caused by stellar rotation rather than a planet. Both the 43-day planet (designated 55 Cancri c) and the 5 AU planet (designated 55 Cancri d) were announced in the same paper, labeled in order of increasing distance from the star. Further measurements which led to the discovery of the inner planet 55 Cancri e in 2004 lent support to the planet hypothesis.

In certain conditions, for example when the cation of the inner electrolyte is Cu2+ or Ag2+, regular sheets consisting of colloidal grains are formed . This phenomenon is especially striking when the reactions run in poly(vinyl)alcohol gels, and the speed of the precipitation front falls below about 0.3 μm/s. The finest microscopic patterns have been observed in the NaOH+AgNO3 reactions, where the periodicity dropped below 10 μm. The chemical mechanism of this pattern formation is not fully understood, but computer simulations based on phase separation described by the Cahn-Hilliard equation with a moving source front exhibit the most important properties of the building of the microscopic patterns .

In the taiga a very strange phenomenon forms — a wall in the form of a dome about two kilometers in diameter from a foggy blanket that disappears and appears with a certain periodicity, and presumably constitutes a powerful electrostatic charge. This strange Wall attracts scientists who in the process of research find out that it causes the viewer to see different visions from the past. Under the dome of the Wall is a research station, scientist Lomov (Lev Krugly) has been working there for the third month. Lomov believes that the Wall is an envoy of a different civilization, and, despite the futility of his attempts, continues to attempt contact.

Hellmut Ludwig Späth (4 December 1885 – 15 February 1945), the son of Franz and Wilhelmine Späth, became the sixth and last manager of the Späth nursery on the death of his father in 1913. After studies at Cambridge, Hellmut returned to Berlin in 1910 and received his doctorate in 1912 from the Berlin Agricultural College. His dissertation was titled The locust drive - a contribution to the knowledge of periodicity and annual ring formation in deciduous woody plants, and was published by Paul Parey. Hellmut revived the nursery's fortunes during the Depression by joining the Nazi Party and obtaining lucrative landscaping contracts for the new autobahns and other public works.

However, he found that the curve departed from a keplerian orbit and even suggested that it was a triple star system to explain the irregularities. The periodic variation in radial velocity of the Cepheid variables was later explained as being due to pulsations in the atmosphere of the star. The periodicity of the star is itself variable, a trend first noted by German astronomer Paul Guthnick in 1920, who suspected that the period change was the result of an orbiting companion. In 1930, Danish astronomer Axel Nielsen suggested that the change was instead the result in a steady decrease of about 3.6 seconds per year in the period.

The mycelia of this species, grown in laboratory culture, have also been shown to be bioluminescent. Early studies demonstrated that short-wave ultraviolet light (at a wavelength of 280 nm) reversibly inhibited the luminescence of P. stypticus mycelia, while longer wavelength (366 nm) ultraviolet was stimulatory. Further, the fungus exhibited a pronounced diurnal periodicity, and maximum luminescence was noted between 6 and 9 pm, regardless as to whether the mycelial cultures were incubated in continuous light, continuous darkness, or a normal day-night cycle. The mycelia of P. stipticus grown submerged in liquid were non- luminescent, but became luminescent while growing on solid substrata.

If these regions are periodically replicated in the frequency domain such that there is zero overlap between any two regions, then by periodically replicating the square region of support, we effectively sample the continuous signal on a rectangular lattice. Similarly periodic replication of the hexagonal region of support maps to sampling the continuous signal on a hexagonal lattice. From U, the periodicity matrix, we can calculate the optimal sampling density for both the rectangular and hexagonal schemes. It is found that in order to completely recover the circularly band-limited signal, the hexagonal sampling scheme requires 13.4% fewer samples than the rectangular sampling scheme.

This theorem was first espoused in the 1930s by Rudolf Peierls. It can be proven using a simple model of the potential for an electron in a 1-D crystal with lattice spacing a. The periodicity of the crystal creates energy band gaps in the \epsilon-k diagram at the edge of the Brillouin zone ka=\pm\pi (similar to the result of the Kronig–Penney model, which helps to explain the origin of band gaps in semiconductors). If the ions each contribute one electron, then the band will be half-filled, up to values of ka=\pm \pi/2 in the ground state.

Two teams of astronomers, Daniel P. Whitmire and Albert A. Jackson IV, and Marc Davis, Piet Hut, and Richard A. Muller, independently published similar hypotheses to explain Raup and Sepkoski's extinction periodicity in the same issue of the journal Nature. This hypothesis proposes that the Sun may have an undetected companion star in a highly elliptical orbit that periodically disturbs comets in the Oort cloud, causing a large increase of the number of comets visiting the inner Solar System with a consequential increase of impact events on Earth. This became known as the "Nemesis" or "Death Star" hypothesis. If it does exist, the exact nature of Nemesis is uncertain.

In his next publication, he tried to reconcile the concept of light quanta with the phenomena of interference and diffraction and came to the conclusion that it was necessary to associate a certain periodicity with quanta. In this case, light quanta were interpreted by him as relativistic particles of very small mass. It remained to extend the wave considerations to any massive particles, and in the summer of 1923 a decisive breakthrough occurred. De Broglie outlined his ideas in a short note "Waves and quanta" (, presented at a meeting of the Paris Academy of Sciences on September 10, 1923), which marked the beginning of the creation of wave mechanics.

ACORN is particularly simple to implement in exact integer arithmetic, in various computer languages, using only a few lines of code.R.S. Wikramaratna, Theoretical and empirical convergence results for additive congruential random number generators, Journal of Computational and Applied Mathematics (2009), doi:10.1016/j.cam.2009.10.015 Integer arithmetic is preferred to the real arithmetic modulo 1 in the original presentation, as the algorithm is then reproducible, producing exactly the same sequence on any machine and in any language, and its periodicity is mathematically provable. The ACORN generator has not seen the wide adoption of some other PRNGs, although it is included in the Fortran and C library routines of NAG Numerical Library.

The aurorae are related to the powerful saturnian kilometric radiation (SKR), which spans the frequency interval between 100 kHz to 1300 kHz and was once thought to modulate with a period equal to the planet's rotation. However, later measurements showed that the periodicity of the SKR's modulation varies by as much as 1%, and so probably does not exactly coincide with Saturn’s true rotational period, which as of 2010 remains unknown. Inside the magnetosphere there are radiation belts, which house particles with energy as high as tens of megaelectronvolts. The energetic particles have significant influence on the surfaces of inner icy moons of Saturn.

61P/Shajn–Schaldach is a periodic comet in the Solar System with a current orbital period of 7.49 years. It was discovered on 18 September 1949 on a photographic plate by Pelageja F. Shajn at the Simeiz Observatory, Crimea, part of the Crimean Astrophysical Observatory. It was also discovered independently two days later by Robert D. Schaldach at the Lowell Observatory in Arizona, US, also on a photographic plate. Shajn then found evidence of the comet on earlier photographs taken on August 28 and September 4. The first computations of the comet's orbit gave a perihelion date of between December 1949 and October 1950 with a periodicity of 7.76 years.

All representation of the symmetric groups are real (and in fact rational), since we can build a complete set of irreducible representations using Young tableaux. All representations of the rotation groups on odd-dimensional spaces are real, since they all appear as subrepresentations of tensor products of copies of the fundamental representation, which is real. Further examples of real representations are the spinor representations of the spin groups in 8k−1, 8k, and 8k+1 dimensions for k = 1, 2, 3 ... This periodicity modulo 8 is known in mathematics not only in the theory of Clifford algebras, but also in algebraic topology, in KO-theory; see spin representation.

Bignami and his colleague Machiafava published a 169-page monograph On Summer- Autumnal Fevers in 1892, which was translated into English in 1894. They were the first to distinguish symptoms of Plasmodium falciparum, the causative agent of tertian malaria, from benign forms. They found that the malaria parasites were spherical in nature (rather than filamentous, as generally believed), mainly intraerythrocytic (rather than free living), that the liberation of spores at segmentation (schizont rupture) caused fever, and that there were different species of malaria parasites (each with its own different characteristics, notably fever periodicity). They observed that malignant malaria was caused only by the parasite species causing aestivo-autumnal malaria.

Abel wrote a fundamental work on the theory of elliptic integrals, containing the foundations of the theory of elliptic functions. While travelling to Paris he published a paper revealing the double periodicity of elliptic functions, which Adrien-Marie Legendre later described to Augustin-Louis Cauchy as "a monument more lasting than bronze" (borrowing a famous sentence by the Roman poet Horatius). The paper was, however, misplaced by Cauchy. While abroad Abel had sent most of his work to Berlin to be published in the Crelle's Journal, but he had saved what he regarded as his most important work for the French Academy of Sciences, a theorem on addition of algebraic differentials.

At present the mine is focused only on the footwall of the fault, exploiting oblique fractures in the Muzo Formation shales of the western flank of the fault. There appears to be a periodicity to the occurrence of variable thickness () calcite veins (observed between 070/35 and 320/65 orientations), that are the primary target for emerald production. The intersections of vein sets are a fertile setting and may represent an upgrading feature. Where these secondary fractures intersect with the primary vein orientation, anecdotally it has been observed that there appears to be an improvement in both quality (colour and clarity) as well as, sometimes, quantity/size.

It is assumed in this construction that all circles lie within the triangle, and all points of tangency lie on the sides of the triangle. If the problem is generalized to allow circles that may not be within the triangle, and points of tangency on the lines extending the sides of the triangle, then the sequence of circles eventually reaches a periodic sequence of six circles, but may take arbitrarily many steps to reach this periodicity. The name may also refer to Miquel's six circles theorem, the result that if five circles have four triple points of intersection then the remaining four points of intersection lie on a sixth circle.

There are numerous examples of sexual dimorphisms in flowering plants. Sexual dimorphic differences include bud abortion, flower size, flower number per plant, floral longevity, nutrient content of flowers, nectar production, flowering phenology and periodicity, floral fragrances, floral defense against herbivory, and various inflorescence characteristics including total flower number, daily display size, and inflorescence architecture. In animal-pollinated species, these differences affect pollinator visitation, competition for mates, and the evolution of sexual dimorphisms . However, there are constraints placed on animal-pollinated species, because too much divergence could interfere with mating success if pollinators are more attracted to one sex than the other, or if the sexes attract different pollinators.

DMol3 is a commercial (and academic) software package which uses density functional theory with a numerical radial function basis set to calculate the electronic properties of molecules, clusters, surfaces and crystalline solid materials from first principles. DMol3 can either use gas phase boundary conditions or 3d periodic boundary conditions for solids or simulations of lower-dimensional periodicity. It has also pioneered the use of the conductor- like screening model COSMO Solvation Model for quantum simulations of solvated molecules and recently of wetted surfaces. DMol3 permits geometry optimisation and saddle point search with and without geometry constraints, as well as calculation of a variety of derived properties of the electronic configuration.

Hinrichs is one of the discoverers of the periodic laws, which are the basis for the periodic table of elements. Although his contribution is not generally considered as important as those of Dmitri Mendeleev or Lothar Meyer, he presented his ideas as early as 1855 and published his book Programme der Atommechanik in 1867. His periodic table had the form of a spiral, and the elements were placed into the structure according to their atomic mass. Hinrichs also postulated a theory on the cause of the periodicity within the chemical elements based on his theory of the composition of elements out of smaller Panatome.

It can be seen as the study of certain kinds of invariants of large matrices. K-theory involves the construction of families of K-functors that map from topological spaces or schemes to associated rings; these rings reflect some aspects of the structure of the original spaces or schemes. As with functors to groups in algebraic topology, the reason for this functorial mapping is that it is easier to compute some topological properties from the mapped rings than from the original spaces or schemes. Examples of results gleaned from the K-theory approach include the Grothendieck–Riemann–Roch theorem, Bott periodicity, the Atiyah–Singer index theorem, and the Adams operations.

Adult emergence typically commences around mid-afternoon, and reaches a maximum around dusk . Cx. tritaeniorhynchus generally has a biphasic biting profile - with feeding peaking around 7pm, declining throughout the midnight hours, then peaking again around 3am. Periodicity can change dramatically depending on the location, season and climate; further studies are required to determine habits of this vector at each of its different distributions as information on biting activity of vectors can play a vital role in personal protection measures, vector control and biting prevention. Culex tritaeniorhynchus is predominantly an exophilic species which rest outdoors after taking a blood meal, however, this also varies based on geographic location.

The United Nations World Water Development Report The United Nations World Water Development Report (WWDR), is the UN-Water flagship report on water. It is a comprehensive review that gives an overall picture of the state, use and management of the world’s freshwater resources and aims to provide decision-makers with tools to formulate and implement sustainable water policies. From 2003 till 2012, the WWDR was produced and released every three years following a comprehensive approach. As a result of a Global Stakeholder Survey in 2012, UN-Water decided to change the periodicity of the WWDR into an annual production with a thematic focus on different strategic water issues.

Infinitely many distinct tilings may be obtained from a single aperiodic set of tiles.A set of aperiodic prototiles can always form uncountably many different tilings, even up to isometry, as proven by Nikolaï Dolbilin in his 1995 paper The Countability of a Tiling Family and the Periodicity of a Tiling The best-known examples of an aperiodic set of tiles are the various Penrose tiles. The known aperiodic sets of prototiles are seen on the list of aperiodic sets of tiles. The underlying undecidability of the domino problem implies that there exists no systematic procedure for deciding whether a given set of tiles can tile the plane.

The infinite general linear group or stable general linear group is the direct limit of the inclusions as the upper left block matrix. It is denoted by either GL(F) or , and can also be interpreted as invertible infinite matrices which differ from the identity matrix in only finitely many places. It is used in algebraic K-theory to define K1, and over the reals has a well-understood topology, thanks to Bott periodicity. It should not be confused with the space of (bounded) invertible operators on a Hilbert space, which is a larger group, and topologically much simpler, namely contractible - see Kuiper's theorem.

According to this view, manifest existence is a "change of condition" and therefore neither the result of creation nor a random event. Everything in the universe is informed by the potentialities present in the "Unknown Root," and manifest with different degrees of Life (or energy), Consciousness, and Matter. The second proposition is "the absolute universality of that law of periodicity, of flux and reflux, ebb and flow". Accordingly, manifest existence is an eternally re-occurring event on a "boundless plane": the playground of numberless Universes incessantly manifesting and disappearing, each one "standing in the relation of an effect as regards its predecessor, and being a cause as regards its successor", doing so over vast but finite periods of time.

For non-linear surface waves there is, in general, ambiguity in splitting the total motion into a wave part and a mean part. As a consequence, there is some freedom in choosing the phase speed (celerity) of the wave. identified two logical definitions of phase speed, known as Stokes's first and second definition of wave celerity: #Stokes's first definition of wave celerity has, for a pure wave motion, the mean value of the horizontal Eulerian flow-velocity ŪE at any location below trough level equal to zero. Due to the irrotationality of potential flow, together with the horizontal sea bed and periodicity the mean horizontal velocity, the mean horizontal velocity is a constant between bed and trough level.

Positive and negative phases of the Arctic Oscillation The Arctic oscillation (AO) or Northern Annular Mode/Northern Hemisphere Annular Mode (NAM) is a weather phenomenon at the Arctic poles north of 20 degrees latitude. It is an important mode of climate variability for the Northern Hemisphere. The southern hemisphere analogue is called the Antarctic oscillation or Southern Annular Mode (SAM). The index varies over time with no particular periodicity, and is characterized by non-seasonal sea-level pressure anomalies of one sign in the Arctic, balanced by anomalies of opposite sign centered at about 37–45° N.Arctic Oscillation (AO) time series, 1899 – June 2002 The North Atlantic oscillation (NAO) is a close relative of the Arctic oscillation.

Because the Moon's orbit around Earth is inclined by about 5.145° (5° 9') to the orbit of Earth around the Sun, eclipses do not occur at every full and new moon. For an eclipse to occur, the Moon must be near the intersection of the two orbital planes. The periodicity and recurrence of eclipses of the Sun by the Moon, and of the Moon by Earth, is described by the saros, which has a period of approximately 18 years. Because the Moon continuously blocks the view of a half-degree-wide circular area of the sky, the related phenomenon of occultation occurs when a bright star or planet passes behind the Moon and is occulted: hidden from view.

Also a flare star, Proxima has minutes-long outbursts where it brightens by over a magnitude. The Alpha couple revolve in 80-year periodicity and will next appear closest as seen from Earth's telescopes in 2037 and 2038, together as they appear to the naked eye they present the third-brightest "star" in the night sky. One other first magnitude star Beta Centauri is in the constellation in a position beyond Proxima and toward the narrow axis of Crux, thus with Alpha forming a far-south limb of the constellation. Also called Hadar and Agena, it is a double star; the primary is a blue-hued giant star of magnitude 0.6, 525 light-years from Earth.

Wang tiles have recently become a popular tool for procedural synthesis of textures, heightfields, and other large and nonrepeating bidimensional data sets; a small set of precomputed or hand-made source tiles can be assembled very cheaply without too obvious repetitions and without periodicity. In this case, traditional aperiodic tilings would show their very regular structure; much less constrained sets that guarantee at least two tile choices for any two given side colors are common because tileability is easily ensured and each tile can be selected pseudorandomly.. Introduces the idea of using Wang tiles for texture variation, with a deterministic substitution system.. Introduces stochastic tiling.. . Applies Wang Tiles for real-time texturing on a GPU.. . Shows advanced applications.

The presence of the acceleration of gravity g in the periodicity equation (1) for a pendulum means that the local gravitational acceleration of the Earth can be calculated from the period of a pendulum. A pendulum can therefore be used as a gravimeter to measure the local gravity, which varies by over 0.5% across the surface of the Earth.The value of "g" (acceleration due to gravity) at the equator is 9.780 m/s2 and at the poles is 9.832 m/s2, a difference of 0.53%. The pendulum in a clock is disturbed by the pushes it receives from the clock movement, so freeswinging pendulums were used, and were the standard instruments of gravimetry up to the 1930s.

Although the cause of the periodicity in flow is not known for certain, the most accepted theory (first postulated in the early 18th century) is that as groundwater flows continuously into a cavern, it fills a narrow tube that leads upwards from near the base of the cavern, then downwards to the spring. As the water level reaches the high point of the tube, it creates a siphon effect, sucking water out of the chamber. Eventually air rushes into the tube and breaks the siphon, stopping the flow if there is no other source feeding the spring, or reducing the flow if there is a continuous flow from another non-siphon source.Mather (2013), pp.144–9.

Jupiter is a powerful source of radio waves in the spectral regions stretching from several kilohertz to tens of megahertz. Radio waves with frequencies of less than about 0.3 MHz (and thus wavelengths longer than 1 km) are called the Jovian kilometric radiation or KOM. Those with frequencies in the interval of 0.3–3 MHz (with wavelengths of 100–1000 m) are called the hectometric radiation or HOM, while emissions in the range 3–40 MHz (with wavelengths of 10–100 m) are referred to as the decametric radiation or DAM. The latter radiation was the first to be observed from Earth, and its approximately 10-hour periodicity helped to identify it as originating from Jupiter.

The existence of the giant Moiré pattern in graphene nanoribbon (GNR) embedded in hBN indicates that the graphene was highly crystalline and precisely aligned with the h-BN underneath. It was noticed that the Moiré pattern appeared to be stretched along the GNR, while it appeared relaxed laterally. This trend differs from regular hexagons with a periodicity of ∼14 nm, which have always been observed with well-aligned graphene domains on h-BN. This observation gives a strong indication of the in-plane epitaxy between the graphene and the h-BN at the edges of the trench, where the graphene is stretched by tensile strain along the ribbon, due to a lattice mismatch between the graphene and h-BN.

When the noise is very strong a large number of switches occur for each period of the sinusoid and the system response does not show remarkable periodicity. Between these two conditions, there exists an optimal value of the noise that cooperatively concurs with the periodic forcing in order to make almost exactly one switch per period (a maximum in the signal-to-noise ratio). Such a favorable condition is quantitatively determined by the matching of two time scales: the period of the sinusoid (the deterministic time scale) and the Kramers rateKramers, H.A.: Brownian motion in a field of force and the diffusion model of chemical reactions. Physica (Utrecht) 7, 284–304 (1940)} (i.e.

Bartram noted that upon hatching from eggs deposited in the twigs of trees, the young insects ran down to the earth and "entered the first opening that they could find". He reported that he had been able to discover them below the surface, but that others had reportedly found them deep. In 1775, Thomas Jefferson recorded in his "Garden Book" Brood II's 17-year periodicity, writing that an acquaintance remembered "great locust years" in 1724 and 1741, that he and others recalled another such year in 1754 and that the insects had again emerged from the ground at Monticello in 1775. He noted that the females lay their eggs in the small twigs of trees while above ground.

A number of 1798 Notizie del mondo was published two times a week up to 22 May 1797, daily up to 1800 when it returned to be published two times a week. From 5 July 1808 it was published three times a week, from 1809 the periodicity changed many times and in 1815 it was again published daily. The length was usually eight pages when published two times a week, four pages when published more often. By order of the government of the Kingdom of Italy, on 14 March 1812 the publications were interrupted along with all other newspapers in Venice, substituted by the Giornale dipartimentale dell'Adriatico published however always by the Graziosi under the direction of Antonio Caminer.

The new standards required, among other matters, a release calendar with a minimum advance of four months, and substantial improvements in data periodicity and timeliness. The National Nomenclature System (SiNN, for its Spanish acronym) was created, motivated by the need to harmonise the different nomenclatures used for statistics and their important role in transforming data in information systems. It was managed by a team dedicated to the administration, assistance and dissemination of the range of classifications and codes available internationally, regionally and nationally. In 1997, the Federal System of Statistical Publication Distribution (SIDIFE, for its Spanish acronym) was created as a communication channel developed by INDEC to meet the regular demand for statistical data in Argentina.

This includes analysis of chaotic dynamics in an acoustic cavitation bubble field in a liquid (Lauterborn, Holzfuss, and Bilio, 1994). The study of the role of shear stresses in non- Newtonian fluids has been done by Li, Mouline, Choplin, and Midoux (1997). A somewhat related field, the study of controlling such chaotic bubble dynamics (control of chaos), converts them to periodic oscillations, and has an important application to gas–solids in fluidized bed reactors, also applicable to the ammoxidation of propylene to acrylonitrile (Kaart, Schouten, and van den Bleek, 1999). Sarnobat et al.) study the behavior of electrostatic fields on chaotic bubbling in attempt to control the chaos into a lower order periodicity.

Figure 2(a) shows the I-V characteristic of a SQUID where ∆V is the modulation depth of the SQUID due to external magnetic fields. The voltage across a SQUID is a nonlinear periodic function of the applied magnetic field, with a periodicity of one flux quantum, Φ0=2.07×10−15 Tm2 (see Figure 2(b)). In order to convert this nonlinear response to a linear response, a negative feedback circuit is used to apply a feedback flux to the SQUID so as to keep the total flux through the SQUID constant. In such a flux locked loop, the magnitude of this feedback flux is proportional to the external magnetic field applied to the SQUID.

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.

In November's 1939 appeared the first number of the Revista CTC as organ of the Confederación de Trabajadores de Cuba (Cuban Worker Confederation), which constituent congress happened on January 28 of this year. It has a weekly periodicity and uninterruptedly it was keep until 1947, when it was produced the forced division of worker movement. Its director was Lázaro Peña, general secretary of trade union section; and its editor in chief, Carlos Fernández. Sometimes from legality, and many other in pursuit and secrecy conditions, the newspaper Noticias de Hoy, founded by the Partido Socialista Popular (Popular Socialist Party), knew represent and defend the interests of workers, like happened under Fulgencio Batista tyranny, since March 1952 until December 1958.

They found evidence of a planet orbiting the star with a period of about seven years. Although there is a high level of noise in the radial velocity data due to magnetic activity in its photosphere, any periodicity caused by this magnetic activity is expected to show a strong correlation with variations in emission lines of ionized calcium (the Ca II H and K lines). Because no such correlation was found, a planetary companion was deemed the most likely cause. This discovery was supported by astrometric measurements of Epsilon Eridani made between 2001 and 2003 with the Hubble Space Telescope, which showed evidence for gravitational perturbation of Epsilon Eridani by a planet.

However, this hypothesis is still controversial, though is growing in popularity among researchers, as evidence in its favour has mounted. A minor series of glaciations occurred from 460 Ma to 430 Ma. There were extensive glaciations from 350 to 250 Ma. The Late Cenozoic Ice Age has seen extensive ice sheets in Antarctica for the last 34 Ma. During the last 3 Ma ice sheets have also developed on the northern hemisphere. This phase is known as the Quaternary glaciation, and has seen more or less extensive glaciation. These first appeared with a dominant periodicity of 41,000 years, but after the Mid-Pleistocene Transition this changed to high-amplitude cycles with an average period of 100,000 years.

Although sustained production of aldosterone requires persistent calcium entry through low-voltage-activated Ca2+ channels, isolated zona glomerulosa cells are considered nonexcitable, with recorded membrane voltages that are too hyperpolarized to permit Ca2+ channels entry. However, mouse zona glomerulosa cells within adrenal slices spontaneously generate membrane potential oscillations of low periodicity; this innate electrical excitability of zona glomerulosa cells provides a platform for the production of a recurrent Ca2+ channels signal that can be controlled by angiotensin II and extracellular potassium, the 2 major regulators of aldosterone production. Voltage-gated Ca2+ channels have been detected in the zona glomerulosa of the human adrenal, which suggests that Ca2+ channel blockers may directly influence the adrenocortical biosynthesis of aldosterone in vivo.

Topological K-theory was discovered by Atiyah and Friedrich Hirzebruch who were inspired by Grothendieck's proof of the Grothendieck–Riemann–Roch theorem and Bott's work on the periodicity theorem. This paper only discussed the zeroth K-group; they shortly after extended it to K-groups of all degrees, giving the first (nontrivial) example of a generalized cohomology theory. Several results showed that the newly introduced K-theory was in some ways more powerful than ordinary cohomology theory. Atiyah and Todd used K-theory to improve the lower bounds found using ordinary cohomology by Borel and Serre for the James number, describing when a map from a complex Stiefel manifold to a sphere has a cross section.

The brightness has been monitored by the American Association of Variable Star Observers since 1945, and it has been classified as an LC slow irregular variable star, whose apparent magnitude slowly varies between extremes of +0.6 and +1.6, although usually near magnitude +1.0. There is no obvious periodicity, but statistical analyses have suggested periods of 1,733 days or days. No separate long secondary period has been detected, although it has been suggested that primary periods longer than a thousand days are analogous to long secondary periods. Research published in 2018 demonstrated that Ngarrindjeri Aboriginal people from South Australia observed the variability of Antares and incorporated it into their oral traditions as Waiyungari (meaning 'red man').

Metasurfaces have been defined in several ways by researchers. 1, “An alternative approach that has gained increasing attention in recent years deals with one- and two-dimensional (1D and 2D) plasmonic arrays with subwavelength periodicity, also known as metasurfaces. Due to their negligible thickness compared to the wavelength of operation, metasurfaces can (near resonances of unit cell constituents) be considered as an interface of discontinuity enforcing an abrupt change in both the amplitude and phase of the impinging light”. 2, “Our results can be understood using the concept of a metasurface, a periodic array of scattering elements whose dimensions and periods are small compared with the operating wavelength”. 3, “Metasurfaces based on thin films”.

The birth will be auspicious if Prānapada falls in the 2nd (wealthy, fortunate), 4th (good-looking, sincere, faithful, truthful), 5th (doer of good deeds, adept, happy), 9th (intelligent, wealthy, fortunate, serves others), 10th (powerful, intelligent, skilful, expert in carrying out royal orders, pious) or 11th (famous, wealthy, fair-complexioned, attached to mother) bhava counted from the lagna, in other bhavas it indicates an inauspicious birth. The concept of Prānapada lagna appears to be based on the law of periodicity according to which humans, animals and plants could occur only at certain definite intervals. Parasara suggests that in the matter of birth-time rectification Prānapada, Chandra and Gulika have all to be considered.

Dale's PhD research projects include the Wellcome 4-Year PhD Programme in Integrated Molecular, Cellular and Translational Biology and the MRC DTP 4 Year PhD Programme. Dale's lab looks at molecular interactions and crosstalk between various signalling pathways that cells use to communicate in order to build tissues and organs during the establishment of the vertebrae axis. Recent research by Dale and colleagues discovered new insight into the role of Notch in developmental segmentation which has opened avenues to explore the potential association of mis-regulated Notch signalling in the context of cancer. Further details can be found in their primary publication "CDK 1 and CDK 2 regulate NICD 1 turnover and the periodicity of the segmentation clock".

The "Eureka moment" came when the computer simulation showed sharp ten-fold diffraction patterns, similar to the observed ones, emanating from the three-dimensional structure devoid of periodicity. The multiple polyhedral structure was termed later by many researchers as icosahedral glass but in effect it embraces any arrangement of polyhedra connected with definite angles and distances (this general definition includes tiling, for example). Shechtman accepted Blech's discovery of a new type of material and it gave him the courage to publish his experimental observation. Shechtman and Blech jointly wrote a paper entitled "The Microstructure of Rapidly Solidified Al6Mn" and sent it for publication around June 1984 to the Journal of Applied Physics (JAP).

The 1755 Lisbon earthquake, also known as the Great Lisbon earthquake, impacted on Portugal on the morning of Saturday, 1 November, Feast of All Saints, at around 09:40 local time.Between History and Periodicity: Printed and Hand-Written News in 18th-Century Portugal In combination with subsequent fires and a tsunami, the earthquake almost totally destroyed Lisbon and adjoining areas. Seismologists today estimate the Lisbon earthquake had a magnitude of 8.4 on the moment magnitude scale, with its epicenter in the Atlantic Ocean about west-southwest of Cape St. Vincent. Chronologically it was the third known large scale earthquake to hit the city (there had been one in 1321 and another in 1531).

Flares are not completely understood, but are believed to be caused by strong magnetic fields, which suppress plasma convection and lead to sudden outbursts: strong magnetic fields occur in rapidly rotating stars, while old stars tend to rotate slowly. For Barnard's Star to undergo an event of such magnitude is thus presumed to be a rarity. Research on the star's periodicity, or changes in stellar activity over a given timescale, also suggest it ought to be quiescent; 1998 research showed weak evidence for periodic variation in the star's brightness, noting only one possible starspot over 130 days. Stellar activity of this sort has created interest in using Barnard's Star as a proxy to understand similar stars.

In complex analysis, an elliptic function is a meromorphic function that is periodic in two directions. Just as a periodic function of a real variable is defined by its values on an interval, an elliptic function is determined by its values on a fundamental parallelogram, which then repeat in a lattice. Such a doubly periodic function cannot be holomorphic, as it would then be a bounded entire function, and by Liouville's theorem every such function must be constant. In fact, an elliptic function must have at least two poles (counting multiplicity) in a fundamental parallelogram, as it is easy to show using the periodicity that a contour integral around its boundary must vanish, implying that the residues of all simple poles must cancel.

The attacks on trains in Spain had an additional dimension: not all the swarms were associated with al-Qaeda. While John Arquilla, a professor at the Naval Postgraduate School, cites the ability to plan separate and widely dispersed attacks, coordinated by mobile communications that might originate from a cave on the Afghan-Pakistan border, he does not emphasize the apparent al-Qaeda technique of releasing operational units to local control, once the policy is set. See Clandestine HUMINT operational techniques. The apparent al-Qaeda methodology of letting operational cells decide on their final dates and means of attack exhibit an operational pattern, but not a periodicity that could easily be used for an indications checklist appropriate for a warning center.

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.

HST Saturn portrait from 20 June 2019 From time to time, Saturn is occulted by the Moon (that is, the Moon covers up Saturn in the sky). As with all the planets in the Solar System, occultations of Saturn occur in "seasons". Saturnian occultations will take place monthly for about a 12-month period, followed by about a five-year period in which no such activity is registered. The Moon's orbit is inclined by several degrees relative to Saturn's, so occultations will only occur when Saturn is near one of the points in the sky where the two planes intersect (both the length of Saturn's year and the 18.6-Earth year nodal precession period of the Moon's orbit influence the periodicity).

Radar designers try to use the highest PRF possible commensurate with the other factors that constrain it, as described below. There are two other facets related to PRF that the designer must weigh very carefully; the beamwidth characteristics of the antenna, and the required periodicity with which the radar must sweep the field of view. A radar with a 1° horizontal beamwidth that sweeps the entire 360° horizon every 2 seconds with a PRF of 1080 Hz will radiate 6 pulses over each 1-degree arc. If the receiver needs at least 12 reflected pulses of similar amplitudes to achieve an acceptable probability of detection, then there are three choices for the designer: double the PRF, halve the sweep speed, or double the beamwidth.

The Chaldeans also knew that 251 synodic months ≈ 269 anomalistic months. Hipparchus used the multiple of this period by a factor of 17, because that interval is also an eclipse period, and is also close to an integer number of years (4267 moons : 4573 anomalistic periods : 4630.53 nodal periods : 4611.98 lunar orbits : 344.996 years : 344.982 solar orbits : 126,007.003 days : 126,351.985 rotations). What was so exceptional and useful about the cycle was that all 345-year-interval eclipse pairs occur slightly over 126,007 days apart within a tight range of only about ± hour, guaranteeing (after division by 4267) an estimate of the synodic month correct to one part in order of magnitude 10 million. The 345-year periodicity is whyFootnote 18 of DIO 6 (1996).

364 After a brief stint at the Bhabha Atomic Research Centre, she moved to Canada to pursue a Masters in the philosophy of science at the University of Guelph in 1977 where she wrote a thesis entitled "Changes in the concept of periodicity of light". In 1978, she completed and received her PhD in philosophy at the University of Western Ontario, focusing on philosophy of physics. Her dissertation was titled "Hidden variables and locality in quantum theory" in which she discussed the mathematical and philosophical implications of hidden variable theories that fall outside of the purview of Bell's theorem. She later went on to pursue interdisciplinary research in science, technology, and environmental policy at the Indian Institute of Science and the Indian Institute of Management in Bangalore.

Believers in Planet X/Nibiru have often confused it with Nemesis, a hypothetical star first proposed by physicist Richard A. Muller. In 1984, Muller postulated that mass extinctions were not random, but appeared to occur in the fossil record with a loose periodicity that ranged from 26 to 34 million years. He attributed this supposed pattern to a heretofore undetected companion to the Sun, either a dim red dwarf or a brown dwarf, lying in an elliptical, 26-million-year orbit. This object, which he named Nemesis, would, once every 26 million years, pass through the Oort cloud, the shell of over a trillion icy objects believed to be the source of long-period comets that orbit at thousands of times Pluto's distance from the Sun.

However, in 2010, A. L. Melott and R. K. Bambach found evidence in the fossil record confirming the extinction event periodicity originally claimed by Raup and Sepkoski in 1984, but at a higher confidence level and over a time period nearly twice as long. The Infrared Astronomical Satellite (IRAS) failed to discover Nemesis in the 1980s. The 2MASS astronomical survey, which ran from 1997 to 2001, failed to detect an additional star or brown dwarf in the Solar System. Using newer and more powerful infrared telescope technology which is able to detect brown dwarfs as cool as 150 kelvins out to a distance of 10 light-years from the Sun, the Wide-field Infrared Survey Explorer (WISE survey) has not detected Nemesis.

Despite the completion of the seventh period, experimental chemistry of some transactinides has been shown to be inconsistent with the periodic law. In the 1990s, Ken Czerwinski at University of California, Berkeley observed similarities between rutherfordium and plutonium and dubnium and protactinium, rather than a clear continuation of periodicity in groups 4 and 5\. More recent experiments on copernicium and flerovium have yielded inconsistent results, some of which suggest that these elements behave more like the noble gas radon rather than mercury and lead, their respective congeners. As such, the chemistry of many superheavy elements has yet to be well-characterized, and it remains unclear whether the periodic law can still be used to extrapolate the properties of undiscovered elements.

The stable topology of the Lagrangian Grassmannian and complex Lagrangian Grassmannian is completely understood, as these spaces appear in the Bott periodicity theorem: \Omega(Sp/U) \simeq U/O, and \Omega(U/O) \simeq Z\times BO – they are thus exactly the homotopy groups of the stable orthogonal group, up to a shift in indexing (dimension). In particular, the fundamental group of U/O is infinite cyclic, with a distinguished generator given by the square of the determinant of a unitary matrix, as a mapping to the unit circle. Its first homology group is therefore also infinite cyclic, as is its first cohomology group. Arnold showed that this leads to a description of the Maslov index, introduced by V. P. Maslov.

Although the rarity of many of these elements means that experimental results are not very extensive, their periodic and group trends are less well defined than other periods. Whilst francium and radium do show typical properties of their respective groups, actinides display a much greater variety of behaviour and oxidation states than the lanthanides. These peculiarities are due to a variety of factors, including a large degree of spin-orbit coupling and relativistic effects, ultimately caused by the very high positive electrical charge from their massive atomic nuclei. Periodicity mostly holds throughout the 6d series, and is predicted also for moscovium and livermorium, but the other four 7p elements, nihonium, flerovium, tennessine, and oganesson, are predicted to have very different properties from those expected for their groups.

In superstring theory, the fermionic fields on the closed string may be either periodic or anti-periodic on the circle around the string. States in the "Ramond sector" admit one option (periodic conditions are referred to as Ramond boundary conditions), described by the Ramond algebra, while those in the "Neveu–Schwarz sector" admit the other (anti-periodic conditions are referred to as Neveu–Schwarz boundary conditions), described by the Neveu–Schwarz algebra. For a fermionic field, the periodicity depends on the choice of coordinates on the worldsheet. In the w-frame, in which the worldsheet of a single string state is described as a long cylinder, states in the Neveu–Schwarz sector are anti-periodic and states in the Ramond sector are periodic.

The magnetic field strength on the surface of neutron stars ranges from 104 to 1011 tesla. These are orders of magnitude higher than in any other object: For comparison, a continuous 16 T field has been achieved in the laboratory and is sufficient to levitate a living frog due to diamagnetic levitation. Variations in magnetic field strengths are most likely the main factor that allows different types of neutron stars to be distinguished by their spectra, and explains the periodicity of pulsars. The neutron stars known as magnetars have the strongest magnetic fields, in the range of 108 to 1011 tesla, and have become the widely accepted hypothesis for neutron star types soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs).

AAVSO V-band light curve of Betelgeuse (Alpha Orionis) from Dec 1988 to Aug 2002. Orion, with Betelgeuse at its usual magnitude (left) and during the unusually deep minimum in early 2020 (right) Betelgeuse is classified as a semiregular variable star, indicating that some periodicity is noticeable in the brightness changes, but amplitudes may vary, cycles may have different lengths, and there may be standstills or periods of irregularity. It is placed in subgroup SRc; these are pulsating red supergiants with amplitudes around one magnitude and periods from tens to hundreds of days. Betelgeuse typically shows only small brightness changes near to magnitude +0.5, although at its extremes it can become as bright as magnitude 0.0 or as faint as magnitude +1.6.

The strongest grating operates in the first order - where the periodicity is one-half wave, and the light is reflected backwards. DFB lasers tend to be much more stable than Fabry-Perot or DBR lasers and are used frequently when clean single mode operation is needed, especially in high speed fiber optic telecommunications. Semiconductor DFB lasers in the lowest loss window of optical fibers at about 1.55um wavelength, amplified by Erbium-doped fiber amplifiers (EDFAs), dominate the long distance communication market, while DFB lasers in the lowest dispersion window at 1.3um are used at shorter distances. The simplest kind of a laser is a Fabry-Perot laser, where there are two broad-band reflectors at the two ends of the lasing optical cavity.

In the same year, a New York Times science writer published a popularized version of Diener's proposal, in which, however, he mistakenly credited Flores et al. with the hypothesis' original conception. Pertinent viroid properties listed in 1989 are: # small size, imposed by error-prone replication; # high guanine and cytosine content, which increases stability and replication fidelity; # circular structure, which assures complete replication without genomic tags; # structural periodicity, which permits modular assembly into enlarged genomes; # lack of protein-coding ability, consistent with a ribosome-free habitat; and # in some cases, replication mediated by ribozymes—the fingerprint of the RNA world. The existence, in extant cells, of RNAs with molecular properties predicted for RNAs of the RNA World constitutes an additional argument supporting the RNA World hypothesis.

A simple example is that the 4-fold periodicity of the Fourier transform – and the fact that two-fold Fourier transform reverses direction – can be interpreted by considering the Fourier transform as a 90° rotation in the associated time–frequency plane: 4 such rotations yield the identity, and 2 such rotations simply reverse direction (reflection through the origin). The practical motivation for time–frequency analysis is that classical Fourier analysis assumes that signals are infinite in time or periodic, while many signals in practice are of short duration, and change substantially over their duration. For example, traditional musical instruments do not produce infinite duration sinusoids, but instead begin with an attack, then gradually decay. This is poorly represented by traditional methods, which motivates time–frequency analysis.

It is shining with nearly double the Sun's luminosity and this energy is being radiated from the star's outer atmosphere at an effective temperature of 5,884 K. Lambda Serpentis is moving toward the Solar System with a radial velocity of 66.4 km s−1. In about 166,000 years, this system will make its closest approach of the Sun at a distance of , before moving away thereafter. A periodicity of 1837 days (5.03 years) was suspected by Morbey & Griffith (1987), but it is probably bound to stellar activity. However, McDonald Observatory team has set limits to the presence of one or more planets around Lambda Serpentis with masses between 0.16 and 2 Jupiter masses and average separations spanning between 0.05 and 5.2 Astronomical Units.

This is lower than the separation between the two components of 61 Cygni, and so the two most likely do not share a common atmosphere. The compactness of the astrosphere is likely due to the low mass outflow and the relatively high velocity through the local interstellar medium. 61 Cygni B displays a more chaotic pattern of variability than A, with significant short-term flares. There is an 11.7-year periodicity to the overall activity cycle of B. Both stars exhibit stellar flare activity, but the chromosphere of B is 25% more active than for 61 Cygni A. As a result of differential rotation, the period of rotation varies by latitude from 32 to 47 days, with an average period of 38 days.

With these theoretical developments and the advent of abstract methods (the Peter- Weyl theorem, Pontryagin duality and Banach algebras) a general theory became possible. The general idea of almost-periodicity in relation to a locally compact abelian group G becomes that of a function F in L∞(G), such that its translates by G form a relatively compact set. Equivalently, the space of almost periodic functions is the norm closure of the finite linear combinations of characters of G. If G is compact the almost periodic functions are the same as the continuous functions. The Bohr compactification of G is the compact abelian group of all possibly discontinuous characters of the dual group of G, and is a compact group containing G as a dense subgroup.

Victorian brick making Of particular interest is the tall brick chimney on the west side of Amber House that has survived major earthquakes in 1929 ( Arthur's Pass and Murchison), 1968 (Īnangahua) and 1994 without a single crack blemishing its surface. There has been speculation that, because deep below Amber House are separate beds of shale and sand, these strata have acted like a naturally occurring analogue of the earthquake resistantbase isolators of the Parliament House in Wellington to reduce the incidence of short periodicity lateral waves at Amber House during earthquakes. The evident resilience of this old chimney means that it is even possible that it pre-dates the 1893 magnitude 6.9 Nelson earthquake that moved the spire of Christ Church Cathedral in Nelson nearly a metre out of the vertical plane.

For all 150,000 stars that were watched for transits by Kepler, there are estimates of each star's surface temperature, radius, surface gravity and mass. These quantities are derived from photometric observations taken prior to Kepler's launch at the 1.2 m reflector at Fred Lawrence Whipple Observatory. For KOIs, there is, additionally, data on each transit signal: the depth of the signal, the duration of the signal and the periodicity of the signal (although some signals lack this last piece of information). Assuming the signal is due to a planet, these data can be used to obtain the size of the planet relative to its host star, the planet's distance from the host star relative to the host star's size (assuming zero eccentricity), and the orbital period of the planet.

A 2001 study by Burbidge and Napier found the pattern of periodicity predicted by Karlsson's formula to be present at a high confidence level in three new samples of quasars, concluding that their findings are inexplicable by spectroscopic or similar selection effects. In 2002, Hawkins et al. found no evidence for redshift quantization in a sample of 1647 galaxy-quasar pairs from the 2dF Galaxy Redshift Survey: :"Given that there are almost eight times as many data points in this sample as in the previous analysis by Burbidge & Napier (2001), we must conclude that the previous detection of a periodic signal arose from the combination of noise and the effects of the window function." In response, Napier and Burbidge (2003) argue that the methods employed by Hawkins et al.

Short story collections were thenceforth published in the main series, which at its height had a weekly periodicity with a circulation of 160,000 copies a month. Since the very beginning Urania has been indeed the best selling SF magazine of Italy, also introducing to Italian readers some famed authors like Isaac Asimov, Alfred Elton van Vogt, Robert A. Heinlein, J. G. Ballard, Philip K. Dick and many others. The first editor was Giorgio Monicelli (brother of movie director Mario Monicelli): Monicelli is credited with the invention of the word fantascienza, meaning science-fiction in Italian. From 1964 to 1985 novels and short stories were selected by the renowned Italian writers and intellectuals Carlo Fruttero and Franco Lucentini, who also appeared in the magazine with a few short stories written under pseudonyms.

Phase response curves for light and for melatonin administration In humans and animals, there is a regulatory system that governs the phase relationship of an organism's internal circadian clock to a regular periodicity in the external environment (usually governed by the solar day). In most organisms, a stable phase relationship is desired, though in some cases the desired phase will vary by season, especially among mammals with seasonal mating habits. In circadian rhythm research, a PRC illustrates the relationship between a chronobiotic's time of administration (relative to the internal circadian clock) and the magnitude of the treatment's effect on circadian phase. Specifically, a PRC is a graph showing, by convention, time of the subject's endogenous day along the x-axis and the amount of the phase shift (in hours) along the y-axis.

The validity of the continuum assumption may be verified by a theoretical analysis, in which either some clear periodicity is identified or statistical homogeneity and ergodicity of the microstructure exists. More specifically, the continuum hypothesis/assumption hinges on the concepts of a representative elementary volume and separation of scales based on the Hill–Mandel condition. This condition provides a link between an experimentalist's and a theoretician's viewpoint on constitutive equations (linear and nonlinear elastic/inelastic or coupled fields) as well as a way of spatial and statistical averaging of the microstructure. When the separation of scales does not hold, or when one wants to establish a continuum of a finer resolution than that of the representative volume element (RVE) size, one employs a statistical volume element (SVE), which, in turn, leads to random continuum fields.

Around permanent ice began to build up on Antarctica. The cooling trend continued in the Miocene, with relatively short warmer periods. When South America became attached to North America creating the Isthmus of Panama around , the Arctic region cooled due to the strengthening of the Humboldt and Gulf Stream currents, eventually leading to the glaciations of the Quaternary ice age, the current interglacial of which is the Holocene Epoch. Recent analysis of the geomagnetic reversal frequency, oxygen isotope record, and tectonic plate subduction rate, which are indicators of the changes in the heat flux at the core mantle boundary, climate and plate tectonic activity, shows that all these changes indicate similar rhythms on million years' timescale in the Cenozoic Era occurring with the common fundamental periodicity of ∼13 Myr during most of the time.

At the time of De Valois' move to Berkeley, linear systems analysis was emerging as a tool for studying the early stages of visual processing. Although this technique had long been applied to problems in optics and engineering, vision scientists Fergus Campbell and John Robson Campbell, F. W., & Robson, J. G., "Application of Fourier analysis to the visibility of gratings", Journal of Physiology (London), 197, 551–556 (1967). measured human sensitivity to patterns of spatial sinusoidal gratings of varying periodicity and first proposed spatial frequency selective "channels" to explain a number of psychophysical phenomena in pattern perception. De Valois, consistent with his conviction that perception must be linked to neuronal responses, seized on these findings and began electrophysiological studies of the mechanisms of early visual processing of form.

The upper Vinalopó has two small tributaries, the Marchal (a short stream near Banyeres de Mariola) and the Tarafa (another short stream, which flows through Aspe), but both of these may completely dry out during the Summer. The river in between Villena and Biar with its arid landscape Perhaps more important than these tributaries are the various ramblas or dry riverbeds which discharge into the Vinalopó following extensive periods of rain. This is because, despite being a very dry area, Alicante province periodically suffers (within a periodicity that has been estimated as approximately once every 9 years or so) brief episodes of torrential rain (predominantly during the Autumn months, especially October and November). Following one of these episodes, all the dry riverbeds fill with water and discharge into the Vinalopó.

The first definition of the cyclic homology of a ring A over a field of characteristic zero, denoted :HCn(A) or Hnλ(A), proceeded by the means of an explicit chain complex related to the Hochschild homology complex of A. Connes later found a more categorical approach to cyclic homology using a notion of cyclic object in an abelian category, which is analogous to the notion of simplicial object. In this way, cyclic homology (and cohomology) may be interpreted as a derived functor, which can be explicitly computed by the means of the (b, B)-bicomplex. One of the striking features of cyclic homology is the existence of a long exact sequence connecting Hochschild and cyclic homology. This long exact sequence is referred to as the periodicity sequence.

Five million years of glacial cycles are shown, based on oxygen isotope ratio believed to be a good proxy of global ice volume. The MPT is the transition between the periodicities shown in green. The Mid-Pleistocene Transition (MPT), also known as the Mid-Pleistocene Revolution (MPR)Mark A. Maslin and Andy J. Ridgwell (2005): Mid-Pleistocene revolution and the ‘eccentricity myth’, Geological Society, London, Special Publications, 247, 19-34, 1 January 2005, is a fundamental change in the behaviour of glacial cycles during the Quaternary glaciations. The transition happened approximately 1.25–0.7 million years ago, in the Pleistocene epoch. Before the MPT, the glacial cycles were dominated by a 41,000 year periodicity with low-amplitude, thin ice sheets and a linear relationship to the Milankovitch forcing from axial tilt.

Dmitri Mendeleev, responsible for organizing the known chemical elements in a periodic table. An important breakthrough in making sense of the list of known chemical elements (as well as in understanding the internal structure of atoms) was Dmitri Mendeleev's development of the first modern periodic table, or the periodic classification of the elements. Mendeleev, a Russian chemist, felt that there was some type of order to the elements and he spent more than thirteen years of his life collecting data and assembling the concept, initially with the idea of resolving some of the disorder in the field for his students. Mendeleev found that, when all the known chemical elements were arranged in order of increasing atomic weight, the resulting table displayed a recurring pattern, or periodicity, of properties within groups of elements.

Plasmodium malariae causes a chronic infection that in some cases can last a lifetime. The P. malariae parasite has several differences between it and the other Plasmodium parasites, one being that maximum parasite counts are usually low compared to those in patients infected with P. falciparum or P. vivax. The reason for this can be accounted for by the lower number of merozoites produced per erythrocytic cycle, the longer 72-hour developmental cycle (compared to the 48-hour cycle of P. vivax and P. falciparum), the preference for development in older erythrocytes and the resulting earlier development of immunity by the human host. Another defining feature of P. malariae is that the fever manifestations of the parasite are more moderate relative to those of P. falciparum and P. vivax and fevers show quartan periodicity.

While the diameter of Venus is more than three times that of the Moon, Venus appears smaller, and travels more slowly across the face of the Sun, because it is much farther away from Earth. Transits of Venus are among the rarest of predictable astronomical phenomena. They occur in a pattern that generally repeats every 243 years, with pairs of transits eight years apart separated by long gaps of 121.5 years and 105.5 years. The periodicity is a reflection of the fact that the orbital periods of Earth and Venus are close to 8:13 and 243:395 commensurabilities. The last transit of Venus was on 5 and 6 June 2012, and was the last Venus transit of the 21st century; the prior transit took place on 8 June 2004.

In detail, the question applies to the 'round spheres' and to their tangent bundles: in fact since all exotic spheres have isomorphic tangent bundles, the Radon–Hurwitz numbers ρ(N) determine the maximum number of linearly independent sections of the tangent bundle of any homotopy sphere. The case of N odd is taken care of by the Poincaré–Hopf index theorem (see hairy ball theorem), so the case N even is an extension of that. Adams showed that the maximum number of continuous (smooth would be no different here) pointwise linearly-independent vector fields on the (N − 1)-sphere is exactly ρ(N) − 1\. The construction of the fields is related to the real Clifford algebras, which is a theory with a periodicity modulo 8 that also shows up here.

A number of orbits were subsequently published using visual and speckle-interferometric observations, both alone and in conjunction with spectroscopic data.. In 1999, Söderhjelm published an orbit using speckle-interferometric data together with Hipparcos observations. Neubauer's 1944 work found a small variation in the radial velocity of Beta Coronae Borealis with a periodicity of 320 days, suggesting the presence of a third, lighter, body in the system. A 1999 study of the system by long- baseline infrared interferometry performed at Palomar Observatory found no evidence for this, and showed that any tertiary companion with this period must have mass 10 Jupiter masses or below. This study also found very weak evidence for the presence of a companion with a shorter, 21-day, period, but the data was insufficient to draw a positive conclusion.

Born in Edmonton, London, England, on 26 May 1909, Flint was raised in the London suburb of New Malden until she emigrated with her family to New Zealand in 1921. There, she was educated at St Margaret's College, Christchurch, and went on to study botany at Canterbury University College, graduating with a Master of Science degree in 1936. Her master's thesis was titled The periodicity of the phytoplankton in Lake Sarah, with a consideration of some ecological factors, and required her to carry out field work at Lake Sarah, a sub-alpine lake near the university's field station at Cass. Flint then undertook doctoral studies at Queen Mary College, London, under the supervision of Felix Eugen Fritsch, investigating the changes in distribution of algae in a reservoir at Barn Elms, near Hammersmith.

Since Rader's algorithm only depends upon the periodicity of the DFT kernel, it is directly applicable to any other transform (of prime order) with a similar property, such as a number-theoretic transform or the discrete Hartley transform. The algorithm can be modified to gain a factor of two savings for the case of DFTs of real data, using a slightly modified re- indexing/permutation to obtain two half-size cyclic convolutions of real data;S. Chu and C. Burrus, "A prime factor FTT [sic] algorithm using distributed arithmetic," IEEE Transactions on Acoustics, Speech, and Signal Processing 30 (2), 217-227 (1982). an alternative adaptation for DFTs of real data uses the discrete Hartley transform.Matteo Frigo and Steven G. Johnson, "The Design and Implementation of FFTW3," Proceedings of the IEEE 93 (2), 216–231 (2005).

Along with these, European elections are also held with a periodicity of five years since the country joined the European Union in 1986. Since the revolution, the Party participated in every election, from the late 1970s until 1987, it ran in coalition with the Portuguese Democratic Movement in the United People Alliance (APU). In 1987, the APU was disbanded and since then, the Party participated in coalition with the Ecologist Party "The Greens" inside the Unitarian Democratic Coalition (CDU). The peak of the Party's electoral influence was from the Carnation Revolution until the early 1980s, since then, and mainly after the fall of the Socialist bloc in eastern Europe, the Party's electoral success was reduced, however, it still keeps a presence in the Parliament and still holds the presidency of 34 municipalities and several parishes.

Wilhelm Reich's pre-eminence as founder of the modern field is open to question. His teacher and the founder of psychoanalysis, Sigmund Freud, explored the role of body in neurosis, as well as undertaking research on the therapeutic effects of cocaine (beginning on April 24, 1884, when he ordered his first gram of cocaine from the local apothecary).Freud and Cocaine -- The Deal retrieved from May 22, 2007Freud and cocaine Freud also showed an interest in the nasal reflex neurosis and in vital periodicity, explored during a significant relationship with Wilhelm Fliess between 1887 and 1902.Chiriac J translated by Mihaela Cristea retrieved from May 22, 2007 Wilhelm Fliess believed that the nose was the centre of all human illness through its structural deviations to the passage of breath.

He reported that he had been able to discover them below the surface, but that others had reportedly found them deep. In 1775, Thomas Jefferson recorded in his "Garden Book" the insect's 17-year periodicity, writing that an acquaintance remembered "great locust years" in 1724 and 1741, that he and others recalled another such year in 1754 and that the insects had again emerged from the ground at Monticello in 1775. He noted that the females lay their eggs in the small twigs of trees while above ground. In April 1800, Benjamin Banneker, who lived near Ellicott's Mills, Maryland, wrote in his record book that he recalled a "great locust year" in 1749, a second in 1766 during which the insects appeared to be "full as numerous as the first", and a third in 1783.

Selective catalytic reduction (SCR) injects a reductant such as ammonia or urea — the latter aqueous, where it is known as diesel exhaust fluid, DEF) — into the exhaust of a diesel engine to convert nitrogen oxides (NOx) into gaseous nitrogen and water. SNCR systems have been prototyped that reduce 90% of the NOx in the exhaust system, with commercialized systems being somewhat lower. SCR systems do not necessarily need particulate matter (PM) filters; when SNCR and PM filters are combined, some engines have been shown to be 3-5% more fuel efficient. A disadvantage of the SCR system, in addition to added upfront development cost (which can be offset by compliance and improved performance), is the need to refill the reductant, the periodicity of which varies with the miles driven, load factors, and the hours used.

Malaria became widely recognized in ancient Greece by the 4th century BC, and is implicated in the decline of many city-state populations. The term μίασμα (Greek for miasma): "stain, pollution", was coined by Hippocrates of Kos who used it to describe dangerous fumes from the ground that are transported by winds and can cause serious illnesses. Hippocrates (460–370 BC), the "father of medicine", related the presence of intermittent fevers with climatic and environmental conditions and classified the fever according to periodicity: Gk.:tritaios pyretos / L.:febris tertiana (fever every third day), and Gk.:tetartaios pyretos / L.:febris quartana (fever every fourth day). The Chinese Huangdi Neijing (The Inner Canon of the Yellow Emperor) dating from ~300 BC – 200 AD apparently refers to repeated paroxysmal fevers associated with enlarged spleens and a tendency to epidemic occurrence.

According to Dejter and Delgado,Dejter I. J.; Delgado A. A. "Perfect domination in rectangular grid graphs", J. Combin. Math. Combin. Comput., 70 (2009), 177-196. given a vertex subset S' of a side Pm of an m x n grid graph G, the perfect dominating sets S in G with S' being the intersection of S with V(Pm) can be determined via an exhaustive algorithm of running time O(2m+n). Extending the algorithm to infinite-grid graphs of width m-1, periodicity makes the binary decision tree prunable into a finite threaded tree, a closed walk of which yields all such sets S. The graphs induced by the complements of such sets S can be codified by arrays of ordered pairs of positive integers, for the growth and determination of which a speedier algorithm exists.

The comet's periodicity was first determined in 1705 by English astronomer Edmond Halley, after whom it is now named. During its 1986 apparition, Halley's Comet became the first comet to be observed in detail by spacecraft, providing the first observational data on the structure of a comet nucleus and the mechanism of coma and tail formation. These observations supported a number of longstanding hypotheses about comet construction, particularly Fred Whipple's "dirty snowball" model, which correctly predicted that Halley would be composed of a mixture of volatile ices—such as water, carbon dioxide, and ammonia—and dust. The missions also provided data that substantially reformed and reconfigured these ideas; for instance, it is now understood that the surface of Halley is largely composed of dusty, non-volatile materials, and that only a small portion of it is icy.

It also lacks a YDYVHL sequence at the N-terminal end of the FAT-like carboxy-terminal domain, even though this motif is conserved among the other three CAS family proteins and is an important binding site for the Src SH2 domain. Although this lack of sequence similarity may mean a reduced functionality of the CASS4 protein, molecular modeling analysis performed by Singh and colleagues using p130CAS/BCAR1 structures as templates suggested an almost identical fold between CASS4 and p130CAS/BCAR1 within their SH3 domains, and substantial similarity within 432-591 residues of CASS4 and 449-610 residues of p130Cas/BCAR1 at the level of secondary and tertiary structures. Also, the similar periodicity of α-helices and β-sheets in both CASS4 and p130Cas/BCAR1 provides another confirmation for the idea of well-conserved structures within the family members.

A proportion of this expenditure and income had to be assigned to the Basque Country. Through an approximate calculation, which takes account of the weight of the income and population within the Spanish total, it was stipulated that the proportion was 6.24%. The Quota has a five-yearly periodicity, although there is an annual adjustment of the quantity on the basis of the figures budgeted for and liquidated by the State. This is an essential difference from the design of the Quota up until that time, inasmuch as it involves the unilateral risk represented for the Basque Country of assuming a part of the expenditure on powers that have not been transferred and that depend exclusively on the State, independent of how the conjuncture of the country evolves or whether the tax collection increases or not.

In the course of this work, he introduced Morse–Bott functions, an important generalization of Morse functions. This led to his role as collaborator over many years with Michael Atiyah, initially via the part played by periodicity in K-theory. Bott made important contributions towards the index theorem, especially in formulating related fixed-point theorems, in particular the so-called 'Woods Hole fixed-point theorem', a combination of the Riemann–Roch theorem and Lefschetz fixed-point theorem (it is named after Woods Hole, Massachusetts, the site of a conference at which collective discussion formulated it). The major Atiyah–Bott papers on what is now the Atiyah–Bott fixed-point theorem were written in the years up to 1968; they collaborated further in recovering in contemporary language Ivan Petrovsky on Petrovsky lacunas of hyperbolic partial differential equations, prompted by Lars Gårding.

1910 drawing of the path of Halley's Comet The near Earth asteroid 433 Eros was visited by a probe in the 1990s The first near-Earth objects to be observed by humans were comets. Their extraterrestrial nature was recognised and confirmed only after Tycho Brahe tried to measure the distance of a comet through its parallax in 1577 and the lower limit he obtained was well above the Earth diameter; the periodicity of some comets was first recognised in 1705, when Edmond Halley published his orbit calculations for the returning object now known as Halley's Comet. The 1758–1759 return of Halley's Comet was the first comet appearance predicted in advance. It has been said that Lexell's comet of 1770 was the first discovered Near-Earth object. The first near-Earth asteroid to be discovered was 433 Eros in 1898.

Although stimulus-response mechanisms are the easiest to understand, the nervous system is also capable of controlling the body in ways that do not require an external stimulus, by means of internally generated rhythms of activity. Because of the variety of voltage-sensitive ion channels that can be embedded in the membrane of a neuron, many types of neurons are capable, even in isolation, of generating rhythmic sequences of action potentials, or rhythmic alternations between high-rate bursting and quiescence. When neurons that are intrinsically rhythmic are connected to each other by excitatory or inhibitory synapses, the resulting networks are capable of a wide variety of dynamical behaviors, including attractor dynamics, periodicity, and even chaos. A network of neurons that uses its internal structure to generate temporally structured output, without requiring a corresponding temporally structured stimulus, is called a central pattern generator.

" However, a follow-up study by Bell and McDiarmid shows that Arp's hypothesis about the periodicity in red-shifts cannot be discarded easily. The authors argue (as response to Tang and Zhang (2005) from which the preceding excerpt is taken) that :"The Tang and Zhang (2005) analysis could thus have missed, or misidentified, many of the parent galaxies, which could explain why the pairs they found differed little from what would be expected for a random distribution. In spite of this, although it was not pointed out by these authors, their pairs did show a slight excess near the expected value of 200 kpc….In fact, most of the conclusions reached by Tang and Zhang (2005) appear to have resulted because they have assumed that many of the values [that they have used] are much more accurate than they really are.

Initial studies showed that artificial replicas of the flower surface produced iridescence that bees could recognise. Later work suggested that the irregularities of the plant cells and surface resulted in the periodicity of the striations being too irregular to create clear iridescence and thus suggested that the iridescence is not visible to man and flower visiting insects. More recent papers have presented evidence that the flower is both visibly and measurably iridescent, and the striations have been shown to be sufficiently irregular to generate particularly strong scattering of light at short wavelengths, producing weak iridescence and a 'blue halo' (of which the halo is the dominant visible effect). It has also been demonstrated that the blue scattering increases the foraging efficiency of bumblebees in laboratory environments, although it remains unknown whether this effect translates to a meaningful advantage in the field.

Montsoreau is a listed UNESCO World Heritage Site located in the Loire Valley, and is also listed among the Most Beautiful Villages of France. The flea market of Montsoreau was created in April 1990 by the municipality of Montsoreau in order to develop the commerce and tourism of this small city, and to take full advantage of the city scenery. The city of Montsoreau relied on a local network of antique dealers to define the periodicity (once a month, the second Sunday), and the identity of the event. The market organization relies still today on the antique dealers and elected of the village, one of its characteristics is to summon the second-hand dealers and antique dealers at 5.30 am the morning of the event, and to draw lots available locations on the vieux port docks.

Physiologically, each spectral pitch depends on both temporal and spectral aspects (i.e. periodicity of the waveform and position of excitation on the basilar membrane), but in Terhardt's approach the spectral pitch itself is a purely experiential parameter, not a physical parameter: it is the outcome of a psychoacoustical experiment in which the conscious listener plays an active role. Psychoacoustic measurements and models can predict which partials are "perceptually relevant" in a given complex tone; they are perceptually relevant if you can hear a difference in the whole sound if the frequency or amplitude of a partial is changed). The ear has evolved to separate spectral frequencies, because due to reflection and superposition in everyday environments spectral frequencies are more reliably carriers of environmental information than spectral amplitudes, which in turn are more reliable carriers of environmentally relevant information than phase relationships between partials (when perceived monoaurally).

Periodicity of solar activity with periods longer than the sunspot cycle of about 11 (22) years has been proposed,David H. Hathaway, "The Solar Cycle", Living Reviews in Solar Physics, March 2010, Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany. ISSN 1614-4961 (accessed 19 July 2015) including: The 210 year Suess cycle (a.k.a. "de Vries cycle", named after Hans Eduard Suess and Hessel De Vries respectively) is recorded from radiocarbon studies, although "little evidence of the Suess Cycle" appears in the 400-year sunspot record. The Hallstatt cycle (named after a cool and wet period in Europe when glaciers advanced) is hypothesized to extend for approximately 2,400 years. An as yet unnamed cycle may extend over 6,000 years. In carbon-14 cycles of 105, 131, 232, 385, 504, 805 and 2,241 years have been observed, possibly matching cycles derived from other sources.

In addition to clock skew due to static differences in the clock latency from the clock source to each clocked register, no clock signal is perfectly periodic, so that the clock period or clock cycle time varies even at a single component, and this variation is known as clock jitter. At a particular point in a clock distribution network, jitter is the only contributor to the clock timing uncertainty. As an approximation, it is often useful to discuss the total clock timing uncertainty between two registers as the sum of spatial clock skew (the spatial differences in clock latency from the clock source), and clock jitter (meaning the non-periodicity of the clock at a particular point in the network). Unfortunately, spatial clock skew varies in time from one cycle to the next due to local time-dependent variations in the power supply, local temperature, and noise coupling to other signals.

Eventually, the periodic table was appreciated for its descriptive power and for finally systematizing the relationship between the elements, although such appreciation was not universal. In 1881, Mendeleev and Meyer had an argument via an exchange of articles in British journal Chemical News over priority of the periodic table, which included an article from Mendeleev, one from Meyer, one of critique of the notion of periodicity, and many more. In 1882, the Royal Society in London awarded the Davy Medal to both Mendeleev and Meyer for their work to classify the elements; although two of Mendeleev's predicted elements had been discovered by then, Mendeleev's predictions were not at all mentioned in the prize rationale. Mendeleev's eka-aluminium was discovered in 1875 and became known as gallium; eka-boron and eka-silicium were discovered in 1879 and 1886, respectively, and were named scandium and germanium.

These same theoretical parameters acquired a more ambitious application when Gómez Martínez brings them to practice in the periodicity of the Latin American thinking during the 20th century in books such as Liberation Thought: Projection of Ortega in Latin America (1995) or Leopoldo Zea (1997). Gómez Martínez recognizes three defining moments in 20th Century Latin American thought, which he places in three symbolic dates: 1914, 1939, and 1968. In them, he finds the beginning of three periods of internalization (self- awareness) that, starting with the recognition of its Western affiliation, Latin American thinkers seek cultural independence by striving for solutions to their own existence. In the 1960s Latin American thought is evident, arising from its own context in an original expression, in what we know today as philosophy of liberation, especially in its facets of Liberation Theology (Gustavo Gutiérrez) and Pedagogy of the Oppressed (Paulo Freire).

House sparrows have also been used in studies of nonphotic entrainment (i.e. synchronisation to an external cycle other than light and dark): for example, in constant darkness, a situation in which the birds would normally reveal their endogenous, non-24-hour, "free-running" rhythms of activity, they instead show 24-hour periodicity if they are exposed to two hours of chirp playbacks every 24 hours, matching their daily activity onsets with the daily playback onsets. House sparrows in constant dim light can also be entrained to a daily cycle based on the presence of food. Finally, house sparrows in constant darkness could be entrained to a cycle of high and low temperature, but only if the difference in temperature was large (38 °C versus 6 °C); some of the tested sparrows matched their activity to the warm phase, and others to the cold phase.

Some solids with a high N(E_F) form density waves while others choose a superconducting or magnetic ground state at low temperatures, because of the existence of nesting vectors in the materials' Fermi surfaces. The concept of a nesting vector is illustrated in the Figure for the famous case of chromium, which transitions from a paramagnetic to SDW state at a Néel temperature of 311 K. Cr is a body-centered cubic metal whose Fermi surface features many parallel boundaries between electron pockets centered at \Gamma and hole pockets at H. These large parallel regions can be spanned by the nesting wavevector q shown in red. The real-space periodicity of the resulting spin- density wave is given by 2\pi/q. The formation of an SDW with a corresponding spatial frequency causes the opening of an energy gap that lowers the system's energy.

Accompanying the 11 year quasi-periodicity in sunspots, the large-scale dipolar (north-south) magnetic field component of the Sun also flips every 11 years, however, the peak in the dipolar field lags the peak in the sunspot number, with the former occurring at the minimum between two cycles. Levels of solar radiation and ejection of solar material, the number and size of sunspots, solar flares, and coronal loops all exhibit a synchronized fluctuation, from active to quiet to active again, with a period of 11 years. This cycle has been observed for centuries by changes in the Sun's appearance and by terrestrial phenomena such as auroras. Solar activity, driven both by the sunspot cycle and transient aperiodic processes govern the environment of the Solar System planets by creating space weather and impact space- and ground-based technologies as well as the Earth's atmosphere and also possibly climate fluctuations on scales of centuries and longer.

Instead of examining brain activity for sleep patterns, an alternate approach is to examine any rest/activity cycles that might indicate "behavioural sleep". The following four behavioural criteria are characteristic of sleep in birds and mammals and could be extended to fishes: (1) prolonged inactivity; (2) typical resting posture, often in a typical shelter; (3) alternation with activity in a 24-h cycle; (4) high arousal thresholds. Based on these criteria, many fish species have been observed sleeping. The typical sleep posture of the brown bullhead is with the fins stretched out, the tail lying flat on the bottom, the body inclined to one side at an angle of 10-30 degrees to the vertical, the cardiac and respiratory frequencies much slower than normal, and much less sensitivity to sound and to being touched.Titkov, E.S. (1976) Characteristics of the daily periodicity of wakefulness and rest in the brown bullhead (Ictalurus nebulosus), Journal of Evolutionary Biochemistry and Physiology 12: 305-309.

Comet 322P/SOHO, also designated P/1999 R1, P/2003 R5, P/2007 R5, and P/2011 R4, is the first periodic comet to be discovered using the automated telescopes of the SOHO (SOlar and Heliospheric Observatory) spacecraft, and second to be given a numbered designation, after 321P/SOHO. JPL Horizons next predicts 322P to come to perihelion (closest approach to the Sun) at 2019-Aug-31 12:25 UT. The periodicity of this comet was predicted by Sebastian Hönig, a German graduate student and prolific asteroid discoverer, in 2006. The announcement of the new periodic comet was made after the predicted return was confirmed by SOHO and observer Bo Zhou on 10 September 2007. Out of approximately 1,350 SOHO-observed sungrazer comets, this is the first to be verified as a short-period comet; most sungrazers are long-period comets on near-parabolic orbits that do not repeat for thousands of years, if at all.

Climate data derived from core samples retrieved from closed lake systems in the Mexico's Yucátan and Guatemala showed a period of extensive drought. In 1995, Hodell, Curtis and Brenner published a paleoclimate record from Lake Chichancanab on the Yucatán Peninsula that showed an intense, protracted drought occurred in the 9th century AD and coincided with the Classic Maya collapse. Hodell, Curtis and Brenner returned to Lake Chichancanab in May 2000 and collected new cores while being filmed for a BBC production on drought and Maya prehistory, as part of the BBC series "Ancient Apocalypse". These new cores showed that the devastating drought of the ninth century AD was only one in a series of drought episodes on the Yucatán Peninsula during the last 2,600 years. This research team points out that these dry events occur about every 208 years and coincide with episodes of greater solar intensity that have been shown previously to have a periodicity of 206 years.

The arrangement of the firing fields showed hints of regularity, but the size of the environment was too small for spatial periodicity to be visible in this study. The next set of experiments, reported in 2005, made use of a larger environment, which led to the recognition that the cells were actually firing in a hexagonal grid pattern. The study showed that cells at similar dorsal-to-ventral MEC levels had similar grid spacing and grid orientation but the phase of the grid (the offset of the grid vertices relative to the x and y axes) appeared to be randomly distributed between cells. The periodic firing pattern was expressed independently of the configuration of landmarks, in darkness as well as in the presence of visible landmarks and independently of changes in the animal’s speed and direction, leading the authors to suggest that grid cells expressed a path-integration dependent dynamic computation of the animal’s location.

Halley recognised the importance of the work and returned to Cambridge to arrange its publication with Newton, who instead went on to expand it into his Philosophiæ Naturalis Principia Mathematica published at Halley's expense in 1687.Peter Ackroyd. Newton. Great Britain: Chatto and Windus, 2006. Halley's first calculations with comets were thereby for the orbit of comet Kirch, based on Flamsteed's observations in 1680-1. Although he was to accurately calculate the orbit of the comet of 1682, he was inaccurate in his calculations of the orbit of comet Kirch. They indicated a periodicity of 575 years, thus appearing in the years 531 and 1106, and presumably heralding the death of Julius Caesar in a like fashion in −44 (45 BCE). It is now known to have an orbital period of circa 10,000 years. In 1691, Halley built a diving bell, a device in which the atmosphere was replenished by way of weighted barrels of air sent down from the surface.

In 1914, Swedish physicist Johannes Rydberg noticed that the atomic numbers of the noble gases was equal to doubled sums of squares of simple numbers: 2 = 2·12, 10 = 2(12 \+ 22), 18 = 2(12 \+ 22 \+ 22), 36 = 2(12 \+ 22 \+ 22 \+ 32), 54 = 2(12 \+ 22 \+ 22 \+ 32 \+ 32), 86 = 2(12 \+ 22 \+ 22 \+ 32 \+ 32 \+ 42). This finding was accepted as an explanation of the fixed lengths of periods and led to repositioning of the noble gases from the left edge of the table to the right. Unwillingness of the noble gases to engage in chemical reaction was explained in the alluded stability of closed noble gas electron configurations; from this notion emerged the octet rule. Among the notable works that established the importance of the periodicity of eight were the valence bond theory, published in 1916 by American chemist Gilbert N. Lewis and the octet theory of chemical bonding, published in 1919 by American chemist Irving Langmuir.

Frankel, 1976, pp. 149–50; Buchwald, 1989, pp. 99–103; Darrigol, 2012, pp. 195–6. Corpuscular optics was becoming expensive on assumptions. But in 1813, Biot reported that the case of quartz was simpler: the observable phenomenon (now called optical rotation or optical activity or sometimes rotary polarization) was a gradual rotation of the polarization direction with distance, and could be explained by a corresponding rotation (not oscillation) of the corpuscles.Frankel, 1976, pp. 151–2; Darrigol, 2012, p. 196. Early in 1814, reviewing Biot's work on chromatic polarization, Young noted that the periodicity of the color as a function of the plate thickness – including the factor by which the period exceeded that for a reflective thin plate, and even the effect of obliquity of the plate (but not the role of polarization)—could be explained by the wave theory in terms of the different propagation times of the ordinary and extraordinary waves through the plate.Young, 1855, pp. 269–72.

Further studies have shown that the beta-hairpin loops within the ankyrin repeat domain of ankyrin-B are required for the interaction with the inositol trisphosphate receptor, and a reduction of ankyrin-B in neonatal cardiomyocytes reduces the half-life of the inositol trisphosphate receptor by 3-fold and destabilizes its proper localization; all of these effects were rescued by reintroducing ankyrin-B. Moreover, a specific sequence in ankyrin-B (absent in other ankyrin isoforms) folds as an amphipathic alpha helix is required for normal levels of sodium-calcium exchanger, sodium potassium ATPase and inositol triphosphate receptor in cardiomyocytes, and is regulated by HDJ1/HSP40 binding to this region. Additional insights into ankyrin-B function have come from studies employing ankyrin-B transgenic animals. Cardiomyocytes from ankyrin-B (-/+) mice exhibited irregular spatial patterns and periodicity of calcium release, as well as abnormal distribution of the sarcomplasmic reticular calcium ATPase, SERCA2, and ryanodine receptors; effects that were rescued by transfection of ankyrin-B.

Recent research by Georgiy Revyakin proved initial Vernon theory and showed economic cycles in developed countries overran economic cycles in developing countries.He also presumed economic cycles with different periodicity can be compared to the products with various life-cycles. In case of Kondratiev waves such products correlate with fundamental discoveries implemented in production (inventions which form the technological paradigm: Richard Arkwright's machines, steam engines, industrial use of electricity, computer invention, etc.); Kuznets cycles describe such products as infrastructural components (roadways, transport, utilities, etc.); Juglar cycles may go in parallel with enterprise fixed capital (equipment, machinery, etc.), and Kitchin cycles are characterized by change in the society preferences (tastes) for consumer goods, and time, which is necessary to start the production. Highly competitive market conditions would determine simultaneous technological updates of all economic agents (as a result, cycle formation): in case if a manufacturing technology at an enterprise does not meet the current technological environment, – such company loses its competitiveness and eventually goes bankrupt.

FRB 180916, more formally FRB 180916.J0158+65, is a repeating FRB discovered by CHIME, that later studies found to have originated from a medium-sized spiral galaxy (SDSS J015800.28+654253.0) about 500 million light-years away – the closest FRB discovered to date. It is also the first FRB observed to have a regular periodicity. Bursts are clustered into a period of about four days, followed by a dormant period of about 12 days, for a total cycle length of days. Additional followup studies of the repeating FRB by the Swift XRT and UVOT instruments were reported on 4 February 2020; by the Sardinia Radio Telescope (SRT) and Medicina Northern Cross Radio Telescope (MNC), on 17 February 2020; and, by the Galileo telescope in Asiago, also on 17 February 2020. Further observations were made by the Chandra X-ray Observatory on 3 and 18 December 2019, with no significant x-ray emissions detected at the FRB 180916 location, or from the host galaxy SDSS J015800.28+654253.0.

In audio, a change in polarity refers to an equal phase shift of 180° at all frequencies, usually produced on one channel by reversing the connections of two wires. Some audiophiles claim that reversing the polarities of all the channels simultaneously makes a subtle perceptible difference in the reproduced sound, even though the relative phases of all the channels are preserved.Absolute Phase: A Prerequisite To Optimum Performance The ear is sensitive to the periodicity of a waveform at low frequencies; tests have shown that absolute phase can sometimes be heard by test subjects listening with monaural conditions (a single loudspeaker, or headphones sending the same signal to both ears.) Audio engineer Douglas Self concludes "there is a prima facie case for the audibility of absolute phase", especially for high impulse sounds such as percussion. The concept of absolute phase is rendered irrelevant for any instrument with strings (such as a guitar or piano), or for two or more instruments played together.

The group prepared flexible fibers of polyimide as the synthetic setae structures on the surface of a 5\mum thick film of the same material using electron beam lithography and dry etching in an oxygen plasma. The fibres were 2\mum long, with a diameter of around 500 nm and a periodicity of 1.6\mum, and covered an area of roughly 1 cm2 (see figure on the left). Initially, the team used a silicon wafer as a substrate but found that the tape's adhesive power increased by almost 1,000 times if they used a soft bonding substrate such as Scotch tape – This is because the flexible substrate yields a much higher ratio of the number of setae in contact with the surface over the total number of setae. The result of this "gecko tape" was tested by attaching a sample to the hand of a 15 cm high plastic Spider-Man figure weighing 40 g, which enabled it to stick to a glass ceiling, as is shown in the figure.

Orbitals for > 3 continue alphabetically, omitting j (g, h, i, k, ...) because some languages do not distinguish between the letters "i" and "j". Atomic orbitals are the basic building blocks of the atomic orbital model (alternatively known as the electron cloud or wave mechanics model), a modern framework for visualizing the submicroscopic behavior of electrons in matter. In this model the electron cloud of a multi-electron atom may be seen as being built up (in approximation) in an electron configuration that is a product of simpler hydrogen-like atomic orbitals. The repeating periodicity of the blocks of 2, 6, 10, and 14 elements within sections of the periodic table arises naturally from the total number of electrons that occupy a complete set of s, p, d, and f atomic orbitals, respectively, although for higher values of the quantum number , particularly when the atom in question bears a positive charge, the energies of certain sub-shells become very similar and so the order in which they are said to be populated by electrons (e.g.

The Arecibo message with added color to highlight the separate parts. The actual binary transmission carried no color information. Many scientific discoveries have been made with the observatory. On April 7, 1964, soon after it began operating, Gordon Pettengill's team used it to determine that the rotation period of Mercury was not 88 days, as formerly thought, but only 59 days. In 1968, the discovery of the periodicity of the Crab Pulsar (33 milliseconds) by Lovelace and others provided the first solid evidence that neutron stars exist. In 1974, Hulse and Taylor discovered the first binary pulsar PSR B1913+16, an accomplishment for which they later received the Nobel Prize in Physics. In 1982, the first millisecond pulsar, PSR B1937+21, was discovered by Donald C. Backer, Shrinivas Kulkarni, Carl Heiles, Michael Davis, and Miller Goss. This object spins 642 times per second and, until the discovery of PSR J1748-2446ad in 2005, was identified as the fastest-spinning pulsar. In August 1989, the observatory directly imaged an asteroid for the first time in history: 4769 Castalia.

A leaf that has been in sunlight, then bleached white and stained with iodine turns black, proving its starch content, whereas a leaf from the same plant that has been out of the sun will remain white. A demonstration of this experiment is shown in the second episode of BBC Four's "Botany: A Blooming History" presented by Timothy Walker. Sachs's later papers were almost exclusively published in the three volumes of the Arbeiten des botanischen Instituts in Würzburg (1871–88). Among these are his investigation of the periodicity of growth in length, in connection with which he devised the self-registering auxanometer, by which he established the retarding influence of the highly refrangible rays of the spectrum on the rate of growth; his researches on heliotropism and geotropism, in which he introduced the clinostat; his work on the structure and the arrangement of cells in growing-points; the elaborate experimental evidence upon which he based his "imbibition-theory" of the transpiration-current; his exhaustive study of the assimilatory activity of the green leaf; and other papers of interest.

Artistically, there are no hard breaks or extreme reorientations, which is why the style periods flow into each other and have developed naturally. The stylistic periodicity is structured as follows: :1st period from 1920 to 1925: Expressive style :2nd period from 1926 to 1946: Simplified, moderate style :3rd period from 1947 to 1958: Paupertät style :4th period from 1959 to 1977: style of mirrored intellectual ideas The expressive style of the early phase is influenced by his Leipzig teachers, who felt committed to the music of the 19th century and had a central role model in Max Reger. But not only Reger, but also Alexander Scriabin served Weyrauch - especially in the field of (extended) harmonics and counterpoint - as an ideal in this period. The functioned as a counterpart to the music of the 19th century, since it dismissed it as light music or empty, virtuoso performance music and sought its salvation in the music of the "Old Masters" - for example Heinrich Schütz, but also Johann Sebastian Bach - and their genres and forms.

The Moon's motion is more complex than those of the planets, mainly due to the competing gravitational pulls of the Earth and the Sun. The motion of the Moon can be measured accurately, and is noticeably more complex than that of the planets. The ancient Greek astronomers, Hipparchus and Ptolemy, had noted several periodic variations in the Moon's orbit, such as small oscillations in its orbital eccentricity and the inclination of its orbit to the plane of the ecliptic. These oscillations generally occur on a once-monthly or twice- monthly time-scale. The line of its apses precesses gradually with a period of roughly 8.85 years, while its line of nodes turns a full circle in roughly double that time, 18.6 years.Smith, p. 252. This accounts for the roughly 18-year periodicity of eclipses, the so-called Saros cycle. However, both lines experience small fluctuations in their motion, again on the monthly time-scale. In 1673, Jeremiah Horrocks published a reasonably accurate model of the Moon's motion in which the Moon was assumed to follow a precessing elliptical orbit.

In relation to this, the periodicity in the datings of January and July/August of the years 1775 to 1777, present on the autographs of four of them, is striking. If it is true that the pieces were written as Tafelmusik for the Archbishop of Salzburg, then there must have been specific and regularly recurring events every winter and summer accounting for this pattern; so far, though, none have been found. Even though in the Anstellungsdekret für Joseph Fiala [the decree of appointment for Joseph Fiala, currently in the Landesarchiv Salzburg], issued by the Archbishop on 1 November 1778, one reads > "According to which we most graciously receive and welcome the supplicant > into our service, subject to his good conduct, as first oboist, in order > that the same, both in the Cathedral and at Court or elsewhere as we may > require him, should participate diligently in the music and once again bring > the wind instruments to that condition which they formerly had, so that they > can perform at our command music with wind instruments at table [...]"Neue > Mozart-Ausgabe, Series VII, Volume 1, p. VIII–XIV (1984).

The observed reconstruction is a 2×1 periodicity, explained by the formation of dimers, which consist of paired surface atoms, decreasing the number of dangling bonds by a factor of two. These dimers reconstruct in rows with a high long-range order, resulting in a surface of filled and empty rows. LEED studies and calculations also indicate that relaxations as deep as five layers into the bulk are also likely to occur. The Si (111) structure, by comparison, exhibits a much more complex reconstruction. Cleavage along the (111) surface at low- temperatures results in another 2×1 reconstruction, differing from the (100) surface by forming long pi-bonded chains in the first and second surface layers. However, when heated above 400 °C this structure converts irreversibly to the more complicated 7×7 reconstruction. In addition, a disordered 1×1 structure is regained at temperatures above 850 °C, which can be converted back to the 7×7 reconstruction by slow cooling. The 7×7 reconstruction is modeled according to a dimer-adatom-stacking fault (DAS) model constructed by many research groups over a period of 25 years.

As with circadian rhythms of activity, the spatio-temporal pattern of room visits shifted gradually over several days following a 6-h advance of the day-night cycle, and it ran freely with a non-24 h periodicity for up to 6 days when the birds were placed under constant 24-h dim light and constant food availability. Starlings can show similar patterns, with free-runs up to 11 days in constant dim light. The insectivorous weaver bird Ploceus bicolor can also learn to associate four feeding rooms with four feeding times, and it maintains the correct spatio-temporal pattern even when one of the rooms is blocked on test days (the bird then waits for the next feeding time and visits the appropriate room for that time); however, room blocking disrupts the spatio-temporal pattern in the granivorous weaver bird Euplectes hordaceus, which suggests that time-place learning may be stronger in species for which food in nature is more likely to vary spatio-temporally (as is the case for insects, as opposed to grain). Finally, pigeons can learn to peck one key to get food in the morning, and another key in the afternoon, and they maintain this pattern for four days in constant light.

Comet 29P/Schwassmann–Wachmann, also known as Schwassmann–Wachmann 1, was discovered on November 15, 1927, by Arnold Schwassmann and Arno Arthur Wachmann at the Hamburg Observatory in Bergedorf, Germany. It was discovered photographically, when the comet was in outburst and the magnitude was about 13. Precovery images of the comet from March 4, 1902, were found in 1931 and showed the comet at 12th magnitude. The comet is unusual in that while normally hovering at around 16th magnitude, it suddenly undergoes an outburst. This causes the comet to brighten by 1 to 5 magnitudes. This happens with a frequency of 7.3 outbursts per year, fading within a week or two. The magnitude of the comet has been known to vary from 18th magnitude to 10th magnitude, a more than thousand-fold increase in brightness, during its brightest outbursts. Outbursts are very sudden, rising to maximum in about 2 hours, which is indicative of their cryovolcanic origin; and with the times of outburst modulated by an underlying 57-day periodicity possibly suggesting that its large nucleus is an extremely slow rotator. The comet is a member of a relatively new class of objects called "Centaurs", of which at least 500 are known.

It was issued weekly. Different headlines have been used during its publishing life, such as Novelle del Mondo (news of the world) or Compendio de' foglio più accreditati d'Europa (Summary of the most reliable papers of Europe). This newspaper, on two columns, followed the usual style of the gazettes of early 18th-century, listing the news without title under the town and date where they were obtained. A number of 1754 The content of the Nuovo Postiglione was almost entirely dedicated to foreign affairs and military campaigns. In 1777 it started to have sometime a supplement (“additional paper”) dedicated to a some particular news. On 28 August 1778 Antonio Graziosi started to publish the first concurrent: the newspaper Notizie del mondo. In September 1781 the Nuovo Postiglione started to advertise other books of the same publisher, and it became issued two times a week, even if this change was formally authorized only in 1792. From 22 May 1797 it was published every day but Sunday, on 7 June 1800 it returned bi- weekly, on 28 June 1808 it was published three times a week, a periodicity it maintained except from 1810 to 1812 when it was printed four times a week.