Compounds are created either by unpaired electrons from different atoms forming joint orbitals called covalent bonds, or by the complete transfer of unpaired electrons between atoms, to create paired orbitals in the recipients.
|
|
I unpaired, then re-paired, and re-set up the whole process again.
|
|
I also needed to re-pair my glasses twice after they mysteriously unpaired.
|
|
For example, the noble gases are inert because they have no unpaired electrons.
|
|
Consider how our gut winds its way through the abdominal cavity, sprouting unpaired organs as it goes.
|
|
Thoughts alone won't do much if they remain unpaired with actions, for both good and bad thoughts.
|
|
If there is an odd number, though, as in 3He, the unpaired particle will make the nucleus itself magnetic.
|
|
The oxidizing agents that have accepted electrons become free radicals if the unpaired electrons don't bind to other molecules.
|
|
So at bare minimum, this region is home to 1,503,054 penguins—not including unpaired penguins and any chicks that may be scurrying around.
|
|
It works like this: A single Holmium atom (a large one with many unpaired electrons) is set on a bed of magnesium oxide.
|
|
Right after the Big Bang, the Universe became completely opaque as light bounced and scattered off of the particles in the hot plasma of unpaired protons and electrons.
|
|
The technique is called electron spin resonance spectroscopy (ESR), and it's used to measure the transition frequency between different electron spin rates, or for studying materials with unpaired electrons.
|
|
As described in a paper in the Annual Review of Biophysics, some molecules have an odd number of electrons, leaving some unpaired, making those electrons sensitive to external magnetic fields.
|
|
The Martians made frantic squeaky noises, their unpaired eyes wheeling about in the green muck, and whooshed him again, and the Senator's bodyguards, by now a bit panicky, shot futilely back.
|
|
The repetitive order in which the shells are filled in each row means that elements in each column of the table have the same combination of unpaired electrons, and thus similar properties.
|
|
As a result, the nitrogen atom's unpaired electron acts as a lone "spin," which is like an arrow pointing up or down or, in general, in a superposition of both possible directions.
|
|
You can produce two of these "radical" molecules at the same time—perhaps one molecule gives an electron to another, or a molecule breaks in two such that each piece has an unpaired electron.
|
|
Re-pair your remoteThe Siri remote is a big part of the new Apple TV experience and if it becomes unpaired with your device somehow, press and hold the Menu and Plus buttons to connect it again.
|
|
They were working with "nano-cranes," which are essentially a custom 400-nanometer strand of DNA sticking up out of a substrate, with a flexible base (literally — it's made of unpaired bases) that lets it rotate in any direction.
|
|
"When the final beep-flash pair is later presented, the brain assumes that it must have missed the flash associated with the unpaired beep and quite literally makes up the fact that there must have been a second flash that it missed," Stiles says in the release.
|
|
The vacancy has three unpaired electrons. Two of them make a quasi covalent bond and one remains unpaired. The overall symmetry, however, is axial (trigonal C3V); one can visualize this by imagining the three unpaired vacancy electrons continuously exchanging their roles. The N-V0 thus has one unpaired electron and is paramagnetic.
|
|
When that attribute is considered, the states with one unpaired electron are named "methylylidene" or "hydridocarbon(•)", whereas the excited states with three unpaired electrons are named "methanetriyl" or "hydridocarbon(3•)".
|
|
The hydroxyl radical, Lewis structure shown, contains one unpaired electron In chemistry, a radical is an atom, molecule, or ion that has an unpaired valence electron.IUPAC Gold Book radical (free radical) PDF With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spontaneously dimerize. Most organic radicals have short lifetimes.
|
|
According to Hund's rule, the spins of unpaired electrons are aligned parallel and this gives these molecules paramagnetic properties. The most stable examples of unpaired electrons are found on the atoms and ions of lanthanides and actinides. The incomplete f-shell of these entities does not interact very strongly with the environment they are in and this prevents them from being paired. The ions with the largest number of unpaired electrons are Gd3+ and Cm3+ with seven unpaired electrons.
|
|
Includes Co2+, Ni3+. :Octahedral low-spin:1 unpaired electron, paramagnetic, substitutionally labile. Includes Co2+, Ni3+. Example: [Co(NH3)6]2+. ;d8:Octahedral high-spin: 2 unpaired electrons, paramagnetic, substitutionally labile. Includes Ni2+.
|
|
Includes Cr2+, Mn3+. :Octahedral low-spin: 2 unpaired electrons, paramagnetic, substitutionally inert. Includes Cr2+, Mn3+. ;d5: :Octahedral high-spin: 5 unpaired electrons, paramagnetic, substitutionally labile. Includes Fe3+, Mn2+. Example: [Mn(H2O)6]2+.
|
|
Includes Fe2+, Co3+. Example: [CoF6]3−. :Octahedral low-spin: no unpaired electrons, diamagnetic, substitutionally inert. Includes Fe2+, Ni4+. Example: [Co(NH3)6]3+. ;d7: :Octahedral high-spin: 3 unpaired electrons, paramagnetic, substitutionally labile.
|
|
In contrast, a doublet state contains one unpaired electron and shows splitting of spectral lines into a doublet; and a triplet state has two unpaired electrons and shows threefold splitting of spectral lines.
|
|
The Greek root zyg refers to a pair. 'A-' means not. Thus, azygos means unpaired. The azygos vein is unpaired in that there is only one in the body, mostly on the right side.
|
|
An unpaired electron has a magnetic dipole moment, while an electron pair has no dipole moment because the two electrons have opposite spins so their magnetic dipole fields are in opposite directions and cancel. Thus an atom with unpaired electrons acts as a magnetic dipole and interacts with a magnetic field. Only elements with unpaired electrons exhibit paramagnetism, ferromagnetism, and antiferromagnetism.
|
|
Hyperfine interaction with the unpaired spin of the proton further splits the levels.
|
|
Unpaired fins hyaline, with longitudinal rows of small black spots on interradial membranes.
|
|
Archaeaspinus has an unpaired anterior lobe confined by the furrow to the left side only.
|
|
These states arise from the spins of their unpaired electrons, not their protons or nuclei.
|
|
Metal complexes that have unpaired electrons are magnetic. Considering only monometallic complexes, unpaired electrons arise because the complex has an odd number of electrons or because electron pairing is destabilized. Thus, monomeric Ti(III) species have one "d-electron" and must be (para)magnetic, regardless of the geometry or the nature of the ligands. Ti(II), with two d-electrons, forms some complexes that have two unpaired electrons and others with none.
|
|
For first row transition metal complexes such as Ni2+ and Cu+ also form five-coordinate 18-electron species which vary from square pyramidal to trigonal bipyramidal. :Octahedral high spin: 2 unpaired electrons, paramagnetic, substitutionally labile. :Square planar low spin: no unpaired electrons, diamagnetic, substitutionally inert.
|
|
Non-blunt ends are created by various overhangs. An overhang is a stretch of unpaired nucleotides in the end of a DNA molecule. These unpaired nucleotides can be in either strand, creating either 3' or 5' overhangs. These overhangs are in most cases palindromic.
|
|
Magnetochemistry is concerned with the magnetic properties of chemical compounds. Magnetic properties arise from the spin and orbital angular momentum of the electrons contained in a compound. Compounds are diamagnetic when they contain no unpaired electrons. Molecular compounds that contain one or more unpaired electrons are paramagnetic.
|
|
The multiplicity of a state is defined as 2S + 1, where S is the total electronic spin.Engel and Reid p.473 A high multiplicity state is therefore the same as a high-spin state. The lowest-energy state with maximum multiplicity usually has unpaired electrons all with parallel spin. Since the spin of each electron is 1/2, the total spin is one-half the number of unpaired electrons, and the multiplicity is the number of unpaired electrons + 1.
|
|
Thus, the transition from localized unpaired electrons to itinerant ones partaking in metallic bonding became more comprehensible.
|
|
Ventral part of caudal peduncle covered with plates showing a highly reduced number of odontodes. Dorsal-fin origin slightly anterior to pelvic-fin origin. Dorsal fin short; when adpressed, far from reaching preadipose unpaired plate. Adipose fin roughly triangular, preceded by one, or two fused into one, median unpaired raised plate.
|
|
The free radical ligand is stabilized mainly in two ways. Firstly, as revealed by computational chemistry studies, the unpaired electron is stabilized through delocalization by the aromatic ring of tyrosine and the cross-linked cysteine sulfur, with the oxygen atom of Tyr272 possessing high unpaired electron density. Some experimental evidence also suggests that axial Tyr495 is also involved in unpaired electron delocalization. Secondly, the indole ring of a tryptophan (Trp290) lies above and parallel to Tyrosine-Cysteine, behaving like a shield protecting the radical from the external solvent environment.
|
|
Example: [Ni(NH3)6]2+. :Tetrahedral high-spin: 2 unpaired electrons, paramagnetic, substitutionally labile. Includes Ni2+. Example: [Ni(Cl)4]2-.
|
|
This processing is achieved when the outrons are trans-spliced to unpaired, downstream acceptor sites adjacent to cistron open reading frames.
|
|
The less directional, more diffuse d and f orbitals, in which unpaired electrons reside, overlap less effectively, form weaker bonds and thus dimerisation is generally disfavoured. These d and f orbitals also have comparatively smaller radial extension, disfavouring overlap to form dimers. Relatively more stable entities with unpaired electrons do exist, e.g. the nitric oxide molecule has one.
|
|
In chemistry, a free radical is any atom, molecule, or ion with an unpaired valence electron Free radicals are atoms or molecules containing unpaired electrons. Electrons normally exist in pairs in specific orbitals in atoms or molecules.Orchin M, Macomber RS, Pinhas A, Wilson RM, editors. The Vocabulary and Concepts of Organic Chemistry. 2 ed: John Wiley & Sons; 2005.
|
|
Type I error of unpaired and paired two-sample t-tests as a function of the correlation. The simulated random numbers originate from a bivariate normal distribution with a variance of 1. The significance level is 5% and the number of cases is 60. Power of unpaired and paired two-sample t-tests as a function of the correlation.
|
|
The multiplicity is also equal to the number of unpaired electrons plus one.Miessler and Tarr p.33 Therefore, the term with lowest energy is also the term with maximum S \, and maximum number of unpaired electrons. # For a given multiplicity, the term with the largest value of the total orbital angular momentum quantum number L \, has the lowest energy.
|
|
This isotope has one unpaired proton and one unpaired neutron, so either the proton or the neutron can decay. This particular nuclide (though not all nuclides in this situation) is almost equally likely to decay through proton decay by positron emission (18%) or electron capture (43%) to , as it is through neutron decay by electron emission (39%) to .
|
|
These nudibranchs are characterized by an unpaired oral gland. In their genital system, the male duct is separate from the female duct.
|
|
Periodic table with elements that have unpaired electrons coloured In chemistry, an unpaired electron is an electron that occupies an orbital of an atom singly, rather than as part of an electron pair. Each atomic orbital of an atom (specified by the three quantum numbers n, l and m) has a capacity to contain two electrons (electron pair) with opposite spins. As the formation of electron pairs is often energetically favourable, either in the form of a chemical bond or as a lone pair, unpaired electrons are relatively uncommon in chemistry, because an entity that carries an unpaired electron is usually rather reactive. In organic chemistry they typically only occur briefly during a reaction on an entity called a radical; however, they play an important role in explaining reaction pathways.
|
|
File:GWM HahnEchoDecay.gif Pulsed electron paramagnetic resonance could be advanced into electron nuclear double resonance spectroscopy (ENDOR), which utilizes waves in the radio frequencies. Since different nuclei with unpaired electrons respond to different wavelengths, radio frequencies are required at times. Since the results of the ENDOR gives the coupling resonance between the nuclei and the unpaired electron, the relationship between them can be determined.
|
|
The use of these splitting diagrams can aid in the prediction of magnetic properties of coordination compounds. A compound that has unpaired electrons in its splitting diagram will be paramagnetic and will be attracted by magnetic fields, while a compound that lacks unpaired electrons in its splitting diagram will be diamagnetic and will be weakly repelled by a magnetic field.
|
|
A notable example of a radical is the hydroxyl radical (HO•), a molecule that has one unpaired electron on the oxygen atom. Two other examples are triplet oxygen and triplet carbene (:) which have two unpaired electrons. Radicals may be generated in a number of ways, but typical methods involve redox reactions. Ionizing radiation, heat, electrical discharges, and electrolysis are known to produce radicals.
|
|
RNase PhyM is a type of endoribonuclease which is sequence specific for single stranded RNAs. It cleaves 3'-end of unpaired A and U residues.
|
|
None of the primordial (i.e., stable or nearly stable) odd–odd nuclides have spin 0 in the ground state. This is because the single unpaired neutron and unpaired proton have a larger nuclear force attraction to each other if their spins are aligned (producing a total spin of at least 1 unit), instead of anti-aligned. See deuterium for the simplest case of this nuclear behavior.
|
|
In contrast, dioxygen under ambient conditions has two unpaired electrons. Dioxygen is a triplet molecule, since the two unpaired electrons allow for three spin states. The reaction of a triplet molecule with a singlet molecule is spin-forbidden in quantum mechanics. This is the major reasons there is a very high reaction barrier for the extremely thermodynamically favorable reaction of singlet organic molecules with triplet oxygen.
|
|
Molecular oxygen is a good example. Even in the frozen solid it contains di-radical molecules resulting in paramagnetic behavior. The unpaired spins reside in orbitals derived from oxygen p wave functions, but the overlap is limited to the one neighbor in the O2 molecules. The distances to other oxygen atoms in the lattice remain too large to lead to delocalization and the magnetic moments remain unpaired.
|
|
If incidental balls are pocketed on the same stroke that a cribbage is completed, they add to the succession of cribbages the player is "on". When a player fouls by failing to pocket an unpaired cribbage while on a succession of unpaired balls, only unpaired balls are spotted; the prior successful cribbages count toward the score. Normal ball and rail foul rules apply in cribbage. This is a requirement present in most pool games that a player must contact an with the cue ball and after that contact, either pocket an object ball, or some ball including the cue ball must contact a rail.
|
|
The gape is large. The "parietals" (postparietals) are small and medially separated by the elongate "frontals" (parietals). The postrostral is large. The (rostro-)premaxilla is unpaired.
|
|
In some of such pairs, the place of articulation is additionally changed (see distinctive features below). There are also unpaired consonants that have no corollary in palatalization.
|
|
Adapted from Proteopedia page. A kissing stem-loop, or kissing stem loop interaction, is formed in RNA when two bases between two hairpin loops pair. These intra- and intermolecular kissing interactions are important in forming the tertiary or quaternary structure of many RNAs. RNA kissing interactions, also called loop-loop pseudoknots, occur when the unpaired nucleotides in one hairpin loop, base pair with the unpaired nucleotides in another hairpin loop.
|
|
Kean then moves on to speak of the uses for copper. He states that copper is used for plumbing, ducts, and tubing in buildings. Next he discusses Gadolinium and how it has unpaired electrons making it one of the most magnetic elements and is used in modern-day science by helping MRIs detect tumors. Gadolinium also can be used to attack cancer tumors because of its array of unpaired electrons.
|
|
The fines are hyaline in appearance with the unpaired fins spotted with brown. The upper and lower margins of the caudal fins are shaded dark brown to black.
|
|
Unpaired terraces occur when either a stream or river encounters material on one side that resists erosion, leaving a single terrace with no corresponding terrace on the resistant side.
|
|
Conversely, if another creature enters play, it can be paired with an unpaired creature with Soulbond. Of the mechanics of Innistrad and Dark Ascension, only undying returns for Avacyn.
|
|
Researchers postulate that embedded carbon atoms with unpaired electrons carry enough of a magnetic moment to lead to strong magnetization. The sheet curvature localizes unpaired electrons by breaking up the π-electron clouds and sterically protects the electrons which normally would be too reactive to persist. The ferromagnetism of the carbon nanofoam is sensitive to time and temperature. Some magnetism is lost within the first few hours of synthesis, however most of it is persistent.
|
|
In real systems, electrons are normally not solitary, but are associated with one or more atoms. There are several important consequences of this: # An unpaired electron can gain or lose angular momentum, which can change the value of its g-factor, causing it to differ from g_e . This is especially significant for chemical systems with transition-metal ions. # Systems with multiple unpaired electrons experience electron–electron interactions that give rise to "fine" structure.
|
|
The monophyly of Catenulida is supported by molecular studies and by at least 3 synapomorphies: the unpaired protonephridium, the unpaired and anterodorsally located testis and the nonmobile sperm. Although there are no known synapomorphies connecting Catenulida to other flatworms (Rhabditophora), molecular studies indicate that they are sister-groups. All characters common to both clades, such as the internal fertilization and the simple gut with a single opening, are found in other groups as well.
|
|
Radicals are uncommon in s- and p-block chemistry, since the unpaired electron occupies a valence p orbital or an sp, sp2 or sp3 hybrid orbital. These orbitals are strongly directional and therefore overlap to form strong covalent bonds, favouring dimerisation of radicals. Radicals can be stable if dimerisation would result in a weak bond or the unpaired electrons are stabilised by delocalisation. In contrast, radicals in d- and f-block chemistry are very common.
|
|
The part of the head which projects in front of the first antennae is known as the rostrum or "beak". The mouthparts are small, and consist of an unpaired labrum, a pair of mandibles, a pair of maxillae, and an unpaired labium. They are used to eat "organic detritus of all kinds" and bacteria. The thorax bears five or six pairs of lobed, leaf-like appendages, each with numerous hairs or setae.
|
|
Free radicals, which contain only a single electron in any orbital, are usually unstable toward losing or picking up an extra electron, so that all electrons in the atom or molecule will be paired. Note that the unpaired electron does not imply charge - free radicals can be positively charged, negatively charged, or neutral. Damage occurs when the free radical encounters another molecule and seeks to find another electron to pair its unpaired electron.
|
|
An example of a repulsive effect is a molecule contorting to minimize the coulombic interactions of atoms that hold like charges. Electronic spin state at it simplest describes the number of unpaired electrons in a molecule. Most molecules including the proteins, carbohydrates, and lipids that make up the majority of life have no unpaired electrons even when charged. Such molecules are called singlet molecules, since their paired electrons have only one spin state.
|
|
Three types of beta decay in competition are illustrated by the single isotope copper-64 (29 protons, 35 neutrons), which has a half-life of about 12.7 hours. This isotope has one unpaired proton and one unpaired neutron, so either the proton or the neutron can decay. This particular nuclide is almost equally likely to undergo proton decay (by positron emission, 18% or by electron capture, 43%) or neutron decay (by electron emission, 39%).
|
|
This earlier pan RNA motif is, however, not found in Zetaproteobacteria. Both motifs consist of simple stem-loop secondary structures, although the earlier pan motif often consists of two stem-loops that are similar to each other. The stem-loops in the earlier pan motif usually have unpaired adenosine nucleotides in asymmetric locations on both sides of the stem-loop. The Zeta-pan motif has an unpaired adenosine only on its 5′ side.
|
|
Two-thirds of these, or 10 percent of all languages, have unpaired voiced fricatives but no voicing contrast between any fricative pair.Maddieson, Ian. Patterns of Sounds. Cambridge University Press, 1984. .
|
|
This class of molecules tends to be slightly more stable than the acyclic analogues as there is a stabilization through the delocalization of the unpaired electrons within the π-system.
|
|
The name for this vein is derived from that of the azygos vein. Azygos means 'unpaired', and hemi means half. This vein mirrors the bottom half of the azygos vein.
|
|
The vomer is unpaired and tapers and reaches a point sharp (Van den Brandt et al., 2018). The vomer also doesn't reach the pterygoid posteriorly (Van den Brandt et al., 2018).
|
|
Another unique thing to the H. haemorrhoidalis is that they have asymmetrical mouthcones that contain an anteclypeus, labrum, labium, paired maxillary stylets and an unpaired left mandible that is well developed.
|
|
He is often credited with being both a pioneer and advocate for the use of electron paramagnetic resonance in biological systems, a technique used to study compounds that have unpaired electrons.
|
|
According to the shell model, protons or neutrons tend to form pairs of opposite total angular momentum. Therefore, the magnetic moment of a nucleus with even numbers of each protons and neutrons is zero, while that of a nucleus with an odd number of protons and even number of neutrons (or vice versa) will have to be that of the remaining unpaired nucleon. For a nucleus with odd numbers of each protons and neutrons, the total magnetic moment will be some combination of the magnetic moments of both of the "last", unpaired proton and neutron. The magnetic moment is calculated through j, l and s of the unpaired nucleon, but nuclei are not in states of well defined l and s.
|
|
An unpaired word is one that, according to the usual rules of the language, would appear to have a related word but does not. Such words usually have a prefix or suffix that would imply that there is an antonym, with the prefix or suffix being absent or opposite. Unpaired words can be the result of one of the words falling out of popular usage, or can be created when only one word of a pair is borrowed from another language, in either case yielding an accidental gap, specifically a morphological gap. Other unpaired words were never part of a pair; their starting or ending phonemes, by accident, happen to match those of an existing morpheme, leading to a reinterpretation.
|
|
This phenomenon occurs because voiced fricatives have developed from lenition of plosives or fortition of approximants. This phenomenon of unpaired voiced fricatives is scattered throughout the world, but is confined to nonsibilant fricatives with the exception of a couple of languages that have but lack . (Relatedly, several languages have the voiced affricate but lack , and vice versa.) The fricatives that occur most often without a voiceless counterpart are – in order of ratio of unpaired occurrences to total occurrences – , , , and .
|
|
Where the helix is unwound, the coding strand consists of unpaired bases, while the template strand consists of an RNA:DNA composite, followed by a number of unpaired bases at the rear. This hybrid consists of the most recently added nucleotides of the RNA transcript, complementary base-paired to the template strand. The number of base-pairs in the hybrid is under investigation, but it has been suggested that the hybrid is formed from the last 10 nucleotides added.
|
|
When outrons are processed, the SL exon is trans-spliced to distinct, unpaired, downstream acceptor sites adjacent to each open reading frame of the polycistronic pre-mRNA, leading to distinct mature capped transcripts.
|
|
The underlying concept is to derive a model with pairs of neutrons and protons instead of unpaired nucleons. The pairs are treated as bosons with different quantum spin (s- and d- bosons, as named according to spin 0 and 2). In an extension of the model, the analogous effect with unpaired fermions has a description using supersymmetrical algebras.Iacchello "Supersymmetry in nuclei" American Scientist, May 1982 In recent times he has worked mainly on the investigation of the quantum mechanical dynamics of molecules (e.g.
|
|
The SO molecule has a triplet ground state similar to O2 and S2, that is, each molecule has two unpaired electrons. The S−O bond length of 148.1 pm is similar to that found in lower sulfur oxides (e.g. S8O, S−O = 148 pm) but is longer than the S−O bond in gaseous S2O (146 pm), SO2 (143.1 pm) and SO3 (142 pm). The molecule is excited with near infrared radiation to the singlet state (with no unpaired electrons).
|
|
The manganese (Mn) atom has a 3d5 electron configuration with five unpaired electrons all of parallel spin, corresponding to a 6S ground state.NIST Atomic Spectrum Database To read the manganese atom levels, type "Mn I" in the Spectrum box and click on Retrieve data. The superscript 6 is the value of the multiplicity, corresponding to five unpaired electrons with parallel spin in accordance with Hund's rule. An atom can have a ground state with two incompletely filled subshells which are close in energy.
|
|
Aerobic organisms release the chemical energy stored in the weak sigma bond of atmospheric dioxygen, the terminal oxidant in cellular respiration. The ground state of dioxygen is known as triplet oxygen, 3O2, because it has two unpaired electrons. The first excited state, singlet oxygen, 1O2, has no unpaired electrons and is metastable. The doublet state requires an odd number of electrons, and so cannot occur in dioxygen without gaining or losing electrons, such as in the superoxide ion () or the dioxygenyl ion ().
|
|
The cyanide ligands may easily be detached in [Fe(CN)6]3−, and hence this complex is poisonous, unlike the iron(II) complex [Fe(CN)6]4− found in Prussian blue, which does not release hydrogen cyanide except when dilute acids are added. Iron shows a great variety of electronic spin states, including every possible spin quantum number value for a d-block element from 0 (diamagnetic) to (5 unpaired electrons). This value is always half the number of unpaired electrons.
|
|
During the breeding seasons, males become jet black, with white margins to the unpaired fins, which is similar to those of O. karongae, but enables them to be distinguished from those of O. squamipinnis.
|
|
In a paramagnetic material there are unpaired electrons; i.e., atomic or molecular orbitals with exactly one electron in them. While paired electrons are required by the Pauli exclusion principle to have their intrinsic ('spin') magnetic moments pointing in opposite directions, causing their magnetic fields to cancel out, an unpaired electron is free to align its magnetic moment in any direction. When an external magnetic field is applied, these magnetic moments will tend to align themselves in the same direction as the applied field, thus reinforcing it.
|
|
It typically requires a sensitive analytical balance to detect the effect and modern measurements on paramagnetic materials are often conducted with a SQUID magnetometer. Paramagnetism is due to the presence of unpaired electrons in the material, so most atoms with incompletely filled atomic orbitals are paramagnetic, although exceptions such as copper exist. Due to their spin, unpaired electrons have a magnetic dipole moment and act like tiny magnets. An external magnetic field causes the electrons' spins to align parallel to the field, causing a net attraction.
|
|
The reactive oxygen ion superoxide is particularly important as the product of the one-electron reduction of dioxygen O2, which occurs widely in nature.Sawyer, D. T. Superoxide Chemistry, McGraw-Hill, Molecular oxygen (dioxygen) is a diradical containing two unpaired electrons, and superoxide results from the addition of an electron which fills one of the two degenerate molecular orbitals, leaving a charged ionic species with a single unpaired electron and a net negative charge of −1. Both dioxygen and the superoxide anion are free radicals that exhibit paramagnetism.
|
|
The vertebral column in bowfin is ossified and in comparison to earlier fish, the centra are the major support for the body, whereas in earlier fish the notochord was the main form of support. Neural spines and ribs provide additional support and help stabilize unpaired fins. In bowfin neural spines and ribs also increase in prominence, an evolutionary aspect that helps them stabilize unpaired fins. The evolution of the vertebral column allows the bowfin to withstand lateral bending that puts the column under compression without breaking.
|
|
However, males seeking mates have different preferences depending on whether they are unpaired or paired. Paired males benefit from high female fidelity, while unpaired males benefit from low female fidelity in order to increase their mating frequencies. Toxicity of seminal fluid: Females benefit from low seminal fluid toxicity, while males benefit from a high toxicity level as it increases their competitive edge. Female fecundity: Males benefit from a high female fecundity as it means that females can produce more offspring and have a higher potential for reproduction.
|
|
These fish have a silvery-grey dorsal surface and a whitish or slightly yellowish ventral surface. The barbels are usually dark. Unpaired fins are usually strongly pigmented with melanophores, while paired fins are less strongly pigmented.
|
|
RsaOG also renamed RsaI is thought to fine-tune the regulation of toxin or invasion mechanisms in S. aureus via trans-acting mechanisms. Its secondary structure contains a pseudoknot formed between two highly conserved unpaired sequences.
|
|
Such a "repeated measures" test compares these measurements within subjects, rather than across subjects, and will generally have greater power than an unpaired test. Another example comes from matching cases of a disease with comparable controls.
|
|
By contrast, gametes of diploid organisms contain only half as many chromosomes. In humans, this is 23 unpaired chromosomes. When two gametes (i.e. a spermatozoon and an ovum) meet during conception, they fuse together, creating a zygote.
|
|
Rheocles species are robust bedotiids with little lateral body compression. R. vatosa and R. derhami are sexually dimorphic, with males exhibiting larger adult size, enhanced coloration and pigmentation, as well as pronounced development of the unpaired fins.
|
|
Methylidyne, or (unsubstituted) carbyne, is an organic compound whose molecule consists of a single hydrogen atom bonded to a carbon atom. It is the parent compound of the carbynes, which can be seen as obtained from it by substitution of other functional groups for the hydrogen. The carbon atom is left with either one or three unpaired electrons (unsatisfied valence bonds), depending on the molecule's excitation state; making it a radical. Accordingly, the chemical formula can be CH• or CH3• (also written as ⫶CH); each dot representing an unpaired electron.
|
|
All the trivalent lanthanide ions, except lanthanum and lutetium, have unpaired f electrons. However, the magnetic moments deviate considerably from the spin-only values because of strong spin-orbit coupling. The maximum number of unpaired electrons is 7, in Gd3+, with a magnetic moment of 7.94 B.M., but the largest magnetic moments, at 10.4–10.7 B.M., are exhibited by Dy3+ and Ho3+. However, in Gd3+ all the electrons have parallel spin and this property is important for the use of gadolinium complexes as contrast reagent in MRI scans.
|
|
For example, the nitrogen atom ground state has three unpaired electrons of parallel spin, so that the total spin is 3/2 and the multiplicity is 4. The lower energy and increased stability of the atom arise because the high-spin state has unpaired electrons of parallel spin, which must reside in different spatial orbitals according to the Pauli exclusion principle. An early but incorrect explanation of the lower energy of high multiplicity states was that the different occupied spatial orbitals create a larger average distance between electrons, reducing electron-electron repulsion energy.
|
|
Unlike modern guitars, which often use steel and bronze strings, vihuelas were gut strung, and usually in paired courses. Gut strings produce a sonority far different from metal, generally described as softer and sweeter. A six course vihuela could be strung in either of two ways: with 12 strings in 6 pairs, or 11 strings in total if a single unpaired chanterelle is used on the first (or highest pitched) course. Unpaired chanterelles were common on all lutes, vihuelas, and (other) early guitars (both Renaissance guitars and Baroque guitars).
|
|
The simulated random numbers originate from a bivariate normal distribution with a variance of 1 and a deviation of the expected value of 0.4. The significance level is 5% and the number of cases is 60. Two-sample t-tests for a difference in mean involve independent samples (unpaired samples) or paired samples. Paired t-tests are a form of blocking, and have greater power than unpaired tests when the paired units are similar with respect to "noise factors" that are independent of membership in the two groups being compared.
|
|
The amino radical has two characteristic electronic states: The electronic states of the amino radical The more stable electronic state is 2B1 states, where the unpaired electron is in the p-orbital perpendicular to the plane of the molecule (π type radical). The high energy electronic state, 2A1, has the two electrons in the p-orbital and the unpaired electron in the sp2 orbital (σ type orbital). Nitrogen centered compounds, such as amines, are nucleophilic in nature, hence, this character is also seen in amino radicals and can be considered to be nucleophilic species.
|
|
Electron paramagnetic resonance, otherwise known as electron spin resonance (ESR), is a spectroscopic technique similar to NMR, but uses unpaired electrons instead. Materials for which this can be applied are much more limited since the material needs to both have an unpaired spin and be paramagnetic. The Mössbauer effect is the resonant and recoil-free emission and absorption of gamma ray photons by atoms bound in a solid form. Resonance in particle physics appears in similar circumstances to classical physics at the level of quantum mechanics and quantum field theory.
|
|
Its parasphenoid endes anterolateral to the unpaired carotid foramen. The lower jaw of Eurhinosaurus had long processus retroarticularis. Atlas and axis abut very closely but were not completely fused together. No rib articulations were present on fluke vertebrae.
|
|
With seven valence electrons and seven available f-orbitals, all seven electrons are unpaired and symmetrically arranged around the metal. The high magnetism and high symmetry combine to make Gd3+ a useful component in NMR spectroscopy and MRI.
|
|
Singlet and triplet carbenes The two classes of carbenes are singlet and triplet carbenes. Singlet carbenes are spin-paired. In the language of valence bond theory, the molecule adopts an sp2 hybrid structure. Triplet carbenes have two unpaired electrons.
|
|
Radical species contain unpaired electron atoms and are very chemically active. Hydride loss is the inverse process of the hydride gain seen before. The final two mechanisms show nucleophilic addition and a reaction using a carbon radical. Mechanism 1.
|
|
Its supraacicular simple chaetae shows distal serration, while subacicular chaetae are compound, its blades showing serration. Its pygidium has a terminal anus, with two pygidial cirri being laterally inserted, as well as an unpaired appendage that is placed ventrally.
|
|
It has unpaired pinnately compound leaves. The flowers with red and white petals have 10 fertile stamens. The pods are rusty brown, and up to 25 cm long and 5 cm wide. E. schomburgkiana ~30 m high; occurs in the Guyanas.
|
|
The interpeduncular nucleus (IPN) is an unpaired, ovoid cell group at the base of the midbrain tegmentum. It is located in the mesencephalon below the interpeduncular fossa. As the name suggests, the interpeduncular nucleus lies in between the cerebral peduncles.
|
|
Gadolinium is used in magnetic resonance imaging as an MRI contrast agent. In the 3+ oxidation state the metal has seven unpaired electrons. This causes water around the contrast agent to relax quickly, enhancing the quality of the MRI scan.
|
|
In order to gain enough electrons to fill their valence shells (see also octet rule), many atoms will form covalent bonds with other atoms. In the simplest case, that of a single bond, two atoms each contribute one unpaired electron, and the resulting pair of electrons is shared between them. Atoms which possess too few bonding partners to satisfy their valences and which possess unpaired electrons are termed "free radicals"; so, often, are molecules containing such atoms. When a free radical exists in an immobilized environment (for example, a solid), it is referred to as an "immobilized free radical" or a "dangling bond".
|
|
Bonding in the cyano radical can be described as a combination of two resonance structures: the structure with the unpaired electron on the carbon is the minor contributor, while the structure with the unpaired electron on the nitrogen (the isocyano radical) is the major contributor. The charge separation in the isocyano radical is similar to that of carbon monoxide. ·CN has a dipole moment of 1.45 Debye and a 2Σ+ ground electronic state. The selection rules are: :N + S = J :J + I = F Where N is the angular momentum, S is the electric spin, and I = 1 is the nuclear spin of 14N.
|
|
Carey, R. Tetras and Barbs: A Complete Guide to the Successful Care and Breeding of Two of the Most Popular Groups of Aquarium Fish. TFH Publications, Inc., 2009 Additionally, tetras possess a long anal fin stretching from a position just posterior of the dorsal fin and ending on the ventral caudal peduncle, and a small, fleshy adipose fin located dorsally between the dorsal and caudal fins. This adipose fin represents the fourth unpaired fin on the fish (the four unpaired fins are the caudal fin, dorsal fin, anal fin, and adipose fin), lending to the name tetra, which is Greek for four.
|
|
A free radical is any atom or molecule that has a single unpaired electron in an outer shell.Erbas M, Sekerci H. IMPORTANCE OF FREE RADICALS AND OCCURRING DURING FOOD PROCESSING. SERBEST RADÏKALLERÏN ONEMÏ VE GIDA ÏSLEME SIRASINDA OLUSUMU. 2011;36(6) 349-56.
|
|
Perkel, J., "Making contact with sequencing's fourth generation" . Biotechniques, 2011. If an introduced dNTP is complementary to the next unpaired nucleotide on the template strand it is incorporated into the growing complementary strand by the DNA polymerase.Alberts B, Molecular Biology of the Cell.
|
|
In an HF molecule the covalent bond is formed by the overlap of the 1s orbital of H and the 2pz orbital of F, each containing an unpaired electron. Mutual sharing of electrons between H and F results in a covalent bond in HF.
|
|
Like its lighter congener nickel(II) fluoride, PdF2 adopts a rutile-type crystal structure, containing octahedrally coordinated palladium, which has the electronic configuration t e. This configuration causes PdF2 to be paramagnetic due to two unpaired electrons, one in each eg-symmetry orbital of palladium.
|
|
Barium ferrate is the chemical compound of formula BaFeO4. This is a rare compound containing iron in the +6 oxidation state. The ferrate(VI) ion has two unpaired electrons, making it paramagnetic. It is isostructural with BaSO4, and contains the tetrahedral [FeO4]2− anion.
|
|
Unpaired rats were used as controls. The rats were conjoined in three ways. In early experiments, the peritoneal cavities were opened and connected between the two rats. In later experiments, to avoid the risk of tangling the two rats’ intestines together, smaller cuts were made.
|
|
As species become more eel-shaped, a whole set of morphological changes has been observed, such as decrease and loss of the adipose fin, continuous unpaired fins, reduction of paired fins, reduction of the eyes, reduction of the skull bones, and hypertrophied jaw muscles.
|
|
NET, but many other programming languages will not accept them. Unpaired marks are preferred for compatibility, as they are easier to type on a wide range of keyboards, and so even in languages where they are permitted, many projects forbid their use for source code.
|
|
For some atoms the spins of several unpaired electrons (s1, s2, ...) are coupled to form a total spin quantum number S.Merzbacher E., Quantum Mechanics (3rd ed., John Wiley 1998) p.430-1 Atkins P. and de Paula J. Physical Chemistry (8th ed., W.H.Freeman 2006), p.
|
|
When preceded and followed by coronal or dorsal consonants, is fronted to . After a cluster of a labial and , is retracted, as in ('to float'); it is also slightly diphthongized to . In native words, only follows unpaired (i.e. the retroflexes and ) and soft consonants.
|
|
The majority of UTF-16 encoder and decoder implementations do this then when translating between encodings. Windows allows unpaired surrogates in filenames and other places, which generally means they have to be supported by software in spite of their exclusion from the Unicode standard.
|
|
Exciplexes provide one of the three dynamic mechanisms by which fluorescence is quenched. A regular exciplex has some charge-transfer (CT) character, and in the extreme case there are distinct radical ions with unpaired electrons. If the unpaired electrons can spin-pair to form a covalent bond, then the covalent bonding interaction can lower the energy of the charge transfer state. Strong CT stabilisation has been shown to lead to a conical intersection of this exciplex state with the ground state in a balance of steric effects, electrostatic interactions, stacking interactions, and relative conformations that can determine the formation and accessibility of bonded exciplexes.
|
|
All things (values of the n and ml quantum numbers) being equal, the order of stability of electrons in a system from least to greatest is unpaired with no other electrons in similar orbitals, unpaired with all degenerate orbitals half filled and the most stable is a filled set of orbitals. To achieve one of these orders of stability, an atom reacts with another atom to stabilize both. For example, a lone hydrogen atom has a single electron in its 1s orbital. It becomes significantly more stable (as much as 100 kilocalories per mole, or 420 kilojoules per mole) when reacting to form H2.
|
|
If energy circumstances are favorable, a given radionuclide may undergo many competing types of decay, with some atoms decaying by one route, and others decaying by another. An example is copper-64, which has 29 protons, and 35 neutrons, which decays with a half-life of about 12.7 hours. This isotope has one unpaired proton and one unpaired neutron, so either the proton or the neutron can decay to the other particle, which has opposite isospin. This particular nuclide (though not all nuclides in this situation) is almost equally likely to decay through positron emission (18%), or through electron capture (43%), as it does through electron emission (39%).
|
|
Octopamine acts as the insect equivalent of norepinephrine and has been implicated in regulating aggression in invertebrates, with different effects on different species. Studies have shown that reducing the neurotransmitter octopamine and preventing coding of tyramine beta hydroxylase (an enzyme that converts tyramine to octopamine) decreases aggression in Drosophila without influencing other behaviors. In insects, octopamine is released by a select number of neurons, but acts broadly throughout the central brain, on all sense organs, and on several non- neuronal tissues. In the thoracic ganglia, octopamine is primarily released by DUM (dorsal unpaired median) and VUM (ventral unpaired median) neurons, which release octopamine onto neural, muscular, and peripheral targets.
|
|
Crystal field theory explains why [FeIII(CN)6]3− has only one unpaired electron Inorganic chemistry has greatly benefited from qualitative theories. Such theories are easier to learn as they require little background in quantum theory. Within main group compounds, VSEPR theory powerfully predicts, or at least rationalizes, the structures of main group compounds, such as an explanation for why NH3 is pyramidal whereas ClF3 is T-shaped. For the transition metals, crystal field theory allows one to understand the magnetism of many simple complexes, such as why [FeIII(CN)6]3− has only one unpaired electron, whereas [FeIII(H2O)6]3+ has five.
|
|
Pentamethylmolybdenum can be prepared from molybdenum pentachloride and dimethyl zinc at low temperature between −70 and −20. Another possible creation route, is from molybdenum oxychloride. Pentamethylmolybdenum is paramagnetic with one unpaired electron. The character of this electron is two thirds 4dz2 and one third 4dx2−y2.
|
|
The Flute of the Chullachaki, p. 53. (Quechua, "one-footed", from chulla or ch'ulla = single, odd, unpaired, asymmetric, chaki = foot;Fabián Potosí C. et al., Ministerio de Educación del Ecuador: Kichwa Yachakukkunapa Shimiyuk Kamu, Runa Shimi - Mishu Shimi, Mishu Shimi - Runa Shimi. Quito (DINEIB, Ecuador) 2009.
|
|
Singlet and Triplet Cobalt Complexes. The ground state of Tpi-Pr,MeCo(CO) has two unpaired electrons. Singlet and triplet states can occur within organometallic complexes as well, such as Tpi-Pr,MeCo(CO)2 and Tpi-Pr,MeCo(CO), respectively. Singlet and Triplet Molecular Orbitals.
|
|
Even at this stage, the black colouration of the unpaired fins will be incompletely developed, and it will not be until sexual maturity is achieved (approximately 8 to 9 months after hatching) that the black border on the anal fin will become a reliable gender differentiation characteristic.
|
|
VCl3 has the common BiI3 structure, a motif that features hexagonally closest-packed chloride framework with vanadium ions occupying the octahedral holes. VBr3 and VI3 adopt the same structure, but VF3 features a structure more closely related to ReO3. VCl3 is paramagnetic and has two unpaired electrons.
|
|
Biometrics Bulletin 1: 80–83. contained the two new statistical tests that still bear his name, the Wilcoxon rank-sum test and the Wilcoxon signed-rank test. These are non-parametric alternatives to the unpaired and paired Student's t-tests respectively. He died on November 18, 1965.
|
|
A study examining the wrestling behaviour of newts found that of the observed wrestling encounters, 90% were "won" by the paired male, meaning he would retain the female newt. The study found that the invading unpaired newt rarely successfully displaces the paired male newt, engaged in amplexus.
|
|
The initiation of thermal degradation involves the loss of a hydrogen atom from the polymer chain as a result of energy input from heat or light. This creates a highly reactive and unstable polymer ‘free radical’ (R•) and a hydrogen atom with an unpaired electron (H•).
|
|
D. microphthalmus is the most elongate, eel-like species of clariid catfish. It also has a reduced skull, and its unpaired fins (dorsal, caudal, and anal fins) are continuous. The pectoral fins, though always present, may be extremely reduced in some specimens. The eyes are small.
|
|
Oxyds must be matched in pairs. An unpaired Oxyd will close if an Oxyd of another pattern or colour is opened. Some landscapes also contain textual clues, which the player can place in their inventory by rolling the marble over them. They can then be selected and read.
|
|
If an ion contains unpaired electrons, it is called a radical ion. Just like uncharged radicals, radical ions are very reactive. Polyatomic ions containing oxygen, such as carbonate and sulfate, are called oxyanions. Molecular ions that contain at least one carbon to hydrogen bond are called organic ions.
|
|
However the ground state of this molecule is paramagnetic, indicating the presence of unpaired electrons. Pauling proposed that this molecule actually contains two three-electron bonds and one normal covalent (two-electron) bond.L. Pauling The Nature of the Chemical Bond (3rd ed., Oxford University Press 1960) chapter 10.
|
|
The inflorescence is a series of flowers, each on a curved pedicel. The flower has small green sepals and tiny white petals. The fruit is an array of four nutlets each lined with comblike prickles, those higher on the plant arranged in pairs and the lower ones unpaired.
|
|
The lightest example is the chromium (Cr) atom with a 3d54s electron configuration. Here there are six unpaired electrons all of parallel spin for a 7S ground state.NIST Atomic Spectrum Database To read the chromium atom levels, type "Cr I" in the Spectrum box and click on Retrieve data.
|
|
The steel is magnetized by a large electric current that flows in the coils of tubing wrapped around the poles. Also, the quadrupole-dipole intersect can be found by multiplying the spin of the unpaired nucleon by its parent atom. A changing magnetic quadrupole moment produces electromagnetic radiation.
|
|
A simple rule of thumb is used in chemistry to determine whether a particle (atom, ion, or molecule) is paramagnetic or diamagnetic: If all electrons in the particle are paired, then the substance made of this particle is diamagnetic; If it has unpaired electrons, then the substance is paramagnetic.
|
|
The gadolinium ion has 7 unpaired electrons with parallel spins and is strongly paramagnetic with an 8S electronic ground state. The relaxation time of the water molecules is affected by their intermittent binding to the paramagnetic centre. This alters their MRI properties and enables contrast enhancement to be achieved.
|
|
Anus surmounted by a spoon shaped hood with a ventral opening, 20 fine annular rings and 14-20 long papillae along edge. On the ventral side of basis, two long cirrus, behind one unpaired longer cirri. .Kirkegaard, J. B. Danmarks Fauna 86, Havbørsteorme II. Copenhagen. Danmarks Naturhistoriske Forening, 1996.
|
|
In cloud forests of northwestern Ecuador, S. nebulatus is often confused with another snake, the Elegant Snail-Eater (Dipsas elegans), which can be distinguished by its pairs of narrow vertical bars between which there is a more pale bar, as opposed to the unpaired vertical bars of S. nebulatus.
|
|
Water-collecting tubes converge into one apical osculum. Colour white in ethanol and light beige when dried. Triactines from the clathroid body range from almost regular to parasagittal with straight actines. Close to the peduncle there are parasagittal spicules with the longest unpaired actine pointing towards the peduncle.
|
|
Because the mechanisms of spin–orbit coupling are well understood, the magnitude of the change gives information about the nature of the atomic or molecular orbital containing the unpaired electron. In general, the g factor is not a number but a second-rank tensor represented by 9 numbers arranged in a 3×3 matrix. The principal axes of this tensor are determined by the local fields, for example, by the local atomic arrangement around the unpaired spin in a solid or in a molecule. Choosing an appropriate coordinate system (say, x,y,z) allows one to "diagonalize" this tensor, thereby reducing the maximal number of its components from 9 to 3: gxx, gyy and gzz.
|
|
To determine the direction to the spin active nucleus from the localized unpaired electron (remember: unpaired electrons are, themselves, spin active) one employs the principle of magnetic angle selection. The exact value of θ is calculated as follows to the right: Hyperfine tensor of dipolar couplingAt θ = 0˚ the ENDOR spectra contain only the component of hyperfine coupling that is parallel to the axial protons and perpendicular to the equatorial protons. At θ = 90˚ ENDOR spectra contain only the component of hyperfine coupling that is perpendicular to the axial protons and parallel to the equatorial protons. The electron nuclear distance (R), in meters, along the direction of the interaction is determined by point-dipole approximation.
|
|
However when two measurements are made for each subject, it is unlikely that the two measurements are independent. If the two measurements within a subject are positively correlated, the unpaired test overstates the variance of , making it a conservative test in the sense that its actual type I error probability will be lower than the nominal level, with a corresponding loss of statistical power. In rare cases, the data may be negatively correlated within subjects, in which case the unpaired test becomes anti- conservative. The paired test is generally used when repeated measurements are made on the same subjects, since it has the correct level regardless of the correlation of the measurements within pairs.
|
|
Hiv virion Reverse transcription Following the strand transfer process, the HIV-DNA and host DNA junctions have unpaired regions of DNA, referred to as DNA "gaps". In addition, the two base pairs at the end of the 5’ region of the viral DNA remain unpaired after the strand transfer. The insertion of the new HIV DNA and the remaining gaps that flank the integration site is currently thought to induce a host cellular DNA damage response, but much of this mechanism remains speculative. The host DNA damage response is thought to be critical in the final step of integration, known as "gap repair" and may require at least three host enzymes - polymerase, nuclease, and ligase.
|
|
One specific three dimensional structure that is commonly observed in rRNA is the A-minor motif. There are four types of A-minor motifs, all of which include many unpaired adenosines. These lone adenosines extend from outward and allow RNA molecules to bind other nucleic acids in the minor groove.
|
|
The anatomy of catenulids is simple and lacks hard parts. The mouth is located anteriorly and connects to a simple pharynx and a simple intestine that forms a ciliated sac. They possess two pairs of nerve cords and often a statocyst, as well as a single protonephridium. The gonads are unpaired.
|
|
The hexatriynyl radical, C6H, is an organic radical molecule consisting of a chain of six carbon atoms terminated by a hydrogen. The unpaired electron is located at the opposite end to the hydrogen atom, as indicated. Both experimental work and computer simulations on this species was done in the early 1990s.
|
|
Tanyptera is a genus of true crane flies; its species are lustrous and black and yellow or red in color. They resemble some Ichneumonidae. Segments of the flagella of males have three outgrowths each (two lower paired and one the upper unpaired). The antennae of the females are distinctly 13-segmented.
|
|
The unpaired electrons leads to the Jahn-Teller effect. (iii) represents the energy level diagram of the ground states not being on an equal level. This shows that there is no presence of the Jahn-Teller effect. This is due to the strong equatorial donor and weak axial donor interactions.
|
|
Ring-necked duck pairs start during spring migration. Unpaired ducks showing up on breeding grounds will most likely end up being non-breeders. The pairs stay together only for reproduction, until then, they separate. The nest is bowl-shaped, built on water in dense emergent vegetation with sedges and woody plants.
|
|
When produced in the reaction with chromium vapour in an electric discharge, the chromium hydride gas glows with a bright bluish-green colour. The ground electronic state of CrH is 6Σ+. The outer electronic configuration is σ2σ1δ2π2. The σ2 electron is the bonding electron with hydrogen, and the other electrons are unpaired.
|
|
Their margins are involved in only a limited amount of digestion and absorption, so their chief function may be to provide support to help the animal maintain its shape. Soft corals, order Alcyonacea, have eight primary mesenteries which alternate with the eight tentacles. The mesenteries are complete and unpaired and bear unilobed filaments.
|
|
Drawing of a Müller's larva Müller's larva or Mulleria is a larva of some Polycladida. It has 8-fold symmetry and is somewhat like a ctenophore. Müller’s larva is ciliated and has several paired and unpaired lobes. The cilia on the lobes are longer than cilia on the rest of the body.
|
|
Variability in attractiveness of male field crickets (Orthoptera: Gryllidae) to females. Anim. Behav. 35, 1240-1248. showed that female G. pennsylvanicus were more attracted to calling song produced by older males than that of younger males. Males found paired with females in the field were also older than unpaired calling males nearby.
|
|
Myleusnema bicornis gen. et sp. n. (Nematoda: Kathlaniidae), an intestinal parasite of a freshwater serrasalmid fish, Myleus ternetzi, from French Guiana. Folia Parasitologica 43:53-59 Its caudal papillae are unique in both number and distribution: 10 subventral pairs and 2 lateral pairs, along with one unpaired papillae in front of the cloaca.
|
|
The skeleton of the peduncle is composed of large diactines with a break on the middle, and parasagittal triactines with a very long unpaired actine and short paired actines. Irregular diactines of variable sizes are present at low numbers in the peduncle. All actines are cylindrical with slightly blunt to sharp points.
|
|
The only compounds in which gallium has a formal oxidation state of +2 are dimeric compounds, such as , which contain a Ga-Ga bond formed from the unpaired electron on each Ga atom. p. 240 Thus the main difference in oxidation states, between transition elements and other elements is that oxidation states are known in which there is a single atom of the element and one or more unpaired electrons. The maximum oxidation state in the first row transition metals is equal to the number of valence electrons from titanium (+4) up to manganese (+7), but decreases in the later elements. In the second row, the maximum occurs with ruthenium (+8), and in the third row, the maximum occurs with iridium (+9).
|
|
Smart rubber will recover its original mechanical strength within several hours of being split and then subsequently recombined. Residual hydrogen bond donors and acceptors responsible for the self-healing properties of the elastomer remain unpaired until the newly exposed surface comes in contact with another complementary surface, allowing formation of new intermolecular hydrogen bonds.
|
|
The larger, more gracile species (e.g. M. alperti, M. galokoa, M. jugum, M. sofina) of Malagidris are remarkably convergent on the widely distributed genus Aphaenogaster. However, all species of Malagidris have two critical features never exhibited by Aphaenogaster species. First, the midpoint of the anterior clypeal margin of Malagidris has a single, stout, unpaired seta.
|
|
Ornithischians shared a unique bone called the predentary (Figure 2). This unpaired bone was situated at the front of the lower jaw, where it extended the dentary (the main lower jaw bone). The predentary coincided with the premaxilla in the upper jaw. Together, they formed a beak-like apparatus used to clip off plant material.
|
|
Vanadocene dichloride is an organometallic complex with formula (η5-C5H5)2VCl2 (commonly abbreviated as Cp2VCl2). It is a structural analogue of titanocene dichloride but with vanadium(IV) instead of titanium(IV). This compound has one unpaired electron, hence Cp2VCl2 is paramagnetic. Vanadocene dichloride is a suitable precursor for variety of bis(cyclopentadienyl)vanadium(IV) compounds.
|
|
McConnell equation describes the proportional dependence of the hyperfine splitting constant a on the spin density \rho (the probability of an unpaired electron being on a particular atom) in aromatic radical compounds such as benzene radical anion C_6H_6^-. a=Q \rho Q is an empirical constant that can range from 2.0 to 2.5 mT.
|
|
Gadolinium(III) chloride, also known as gadolinium trichloride, is GdCl3. It is a colorless, hygroscopic, water-soluble solid. The hexahydrate GdCl3∙6H2O is commonly encountered and is sometimes also called gadolinium trichloride. Gd3+ species are of special interest because the ion has the maximum number of unpaired spins possible, at least for known elements.
|
|
Iron(III) acetylacetonate, Fe(acac)3, is a red high- spin complex that is highly soluble in organic solvents. It is a configurationally labile, high-spin complex with five unpaired electrons. It is occasionally used as a catalyst precursor. Although configurationally labile, Fe(acac)3 has been partially resolved into its Δ and Λ isomers.
|
|
There are two basic types of fluvial terraces, fill terraces and strath terraces. Fill terraces sometimes are further subdivided into nested fill terraces and cut terraces. Both fill and strath terraces are, at times, described as being either paired or unpaired terraces based upon the relative elevations of the surface of these terraces.Pazzaglia, Frank J., in press, 9.2.
|
|
Each oxygen atom in its peroxide ion may have a full octet of 4 pairs of electrons.Cook 1968, p.507 Superoxides are a class of compounds that are very similar to peroxides, but with just one unpaired electron for each pair of oxygen atoms (). These compounds form by oxidation of alkali metals with larger ionic radii (K, Rb, Cs).
|
|
Lancelets have four known kinds of light-sensing structures: Joseph cells, Hesse organs, an unpaired anterior eye and lamellar body, all of which utilize opsins as light receptors. All of these organs and structures are located in the neural tube, with the frontal eye at the front, followed by the lamellar body, the Joseph cells, and the Hesse organs.
|
|
The boulevard, particularly between its cross-sections with boulevard Richard- Lenoir and Place Léon-Blum is host to great textile firms. The unpaired side of the boulevard also has a great number of entertainment and video stores. During the November 2015 Paris attacks, one suicide bomber blew himself up on the Boulevard Voltaire near the Bataclan.
|
|
Where an inscription ends in a single (unpaired) column, this final column is usually read straight downwards. Individual glyph blocks may be composed of a number of elements. These consist of the main sign, and any affixes. Main signs represent the major element of the block, and may be a noun, verb, adverb, adjective, or phonetic sign.
|
|
The cerebellar vermis in an ultrasound image of the fetus at 19 weeks of pregnancy in a sagittal scan. Visualization of median structures including the corpus callosum. The vermis is the unpaired, median portion of the cerebellum that connects the two hemispheres. Both the vermis and the hemispheres are composed of lobules formed by groups of folia.
|
|
The central nervous system is often red or pink because it contains hemoglobin. This stores oxygen for peak activity or when the animal experiences anoxia, for example while burrowing in oxygen-free sediments. Some species have paired cerebral organs, sacs whose only openings are to the outside. Others species have unpaired evertible organs on the front of their heads.
|
|
Its song is particularly noticeable at night because few other birds are singing. This is why its name includes "night" in several languages. Only unpaired males sing regularly at night, and nocturnal song probably serves to attract a mate. Singing at dawn, during the hour before sunrise, is assumed to be important in defending the bird's territory.
|
|
The practice of hybridisation is so ancient that it is not known precisely where it began. Modern Sundanese and Javanese people claim that it first occurred in the Kangean Islands in the Java Sea. The native peoples of the Sunda Archipelago learned that they could persuade young, unpaired wild green junglefowl males to mate with domestic game hens.
|
|
Fullerenes can be considered radical scavengers. With a simple hydrocarbon radical such as the t-butyl radical obtained by thermolysis or photolysis from a suitable precursor the tBuC60 radical is formed that can be studied. The unpaired electron does not delocalize over the entire sphere but takes up positions in the vicinity of the tBu substituent.
|
|
The of this bird is loud and highly variable, resembling chip chewy sweet dichetty. Their calls are low chup's. A 2013 study showed that male Canada warblers have two performance-encoded song types. In Mode I, used mostly during the day, when unpaired either alone or near a female during early nesting, involves stereotyped songs sung slowly and regularly.
|
|
Example of bent electron arrangement. Shows location of unpaired electrons, bonded atoms, and bond angles. (Water molecule) The bond angle for water is 104.5°. Valence shell electron pair repulsion theory, or VSEPR theory ( , ), is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms.
|
|
1H NMR spectrum of 1,1'-dimethylnickelocene, illustrating the dramatic chemical shifts observed in some paramagnetic compounds. The sharp signals near 0 ppm are from solvent.Köhler, F. H., "Paramagnetic Complexes in Solution: The NMR Approach," in eMagRes, 2007, John Wiley. Roughly, the magnitude of A indicates the extent to which the unpaired spin resides on the nucleus.
|
|
100 Whether something is paired or unpaired is an important distinction within the Andean cosmovision. Regina Harrison noted, “Quechua speakers persistently distinguish objects which are not well matched or ‘equal’.Harrison (1989), p. 49 According to Platt, yanantin is the act of rendering equal two things that were once unequal—what he calls “the correction of inequalities.
|
|
Following the law of matching water affinities, chaotrope-chaotrope and kosmotropes-kosmotrope pairs prefer the CIP state; whereas, chaotrope-kosmotrope prefer SIP or unpaired states. Another important lyotropic effect is the pairing of ions to charged headgroups of biological molecules. Vlachy et al. proposed that from chaotropic to kosmotropic headgroups, the ordering follows carboxylate, sulfate and sulfonate groups.
|
|
Materials that are called "paramagnets" are most often those that exhibit, at least over an appreciable temperature range, magnetic susceptibilities that adhere to the Curie or Curie–Weiss laws. In principle any system that contains atoms, ions, or molecules with unpaired spins can be called a paramagnet, but the interactions between them need to be carefully considered.
|
|
The unpaired dorsal plate of the eleventh segment, called the epiproct, is roughly the same length as or longer than the paraproct. This distinguishes them from larvae of the genus Tramea, where the epiproct is shorter than the paraproct. Furthermore, the mouth parts (palpus) have 12–14 bristles and thus fewer than P. hymenaea which has 15–18 bristles.
|
|
Based on definition from IUPAC, radical polymerization is a chain polymerization in which the kinetic- chain carriers are radicals. Usually, the growing chain end bears an unpaired electron. Free radicals can be initiated by many methods such as heating, redox reactions, ultraviolet radiation, high energy irradiation, electrolysis, sonication, and plasma. Free radical polymerization is very important in polymer chemistry.
|
|
However, for the ion Eu3+ which has six unpaired electrons, the orbital angular momentum cancels out the electron angular momentum, and this ion is diamagnetic at zero Kelvin. #Paramagnetism. At least one electron is not paired with another. The atom has a permanent magnetic moment. When placed into a magnetic field, the atom is attracted into the field.
|
|
If there were a covalent bond between the copper ions, the electrons would pair up and the compound would be diamagnetic. Instead, there is an exchange interaction in which the spins of the unpaired electrons become partially aligned to each other. In fact two states are created, one with spins parallel and the other with spins opposed.
|
|
The Women's Individual Pursuit B track cycling event at the 2012 Summer Paralympics took place on September 2 at London Velopark. This class was for blind and visually impaired cyclists riding with a sighted pilot. Eleven pairs from nine different nations competed. The competition began with five head to head races and one unpaired ride between the eleven riders.
|
|
This is, in part, because TDD duplexing is not normally allowed on cellular, PCS/PCN, and 3G frequencies. TDD technologies open up the usage of left-over unpaired spectrum. Europe-wide, several bands are provided either specifically for UMTS-TDD or for similar technologies. These are 1900 MHz and 1920 MHz and between 2010 MHz and 2025 MHz.
|
|
The three spine rows are oriented at the same angles as the basal rays. The spines and ray apex appear to have a granular rather than a smooth surface. The small, sagittal tetractines are approximately the same size as the small regular tetractines with paired rays curved towards the unpaired ray. They constitute a small percentage of the tetractines.
|
|
For example, CuII2(OAc)4(H2O)2 is almost diamagnetic below room temperature whereas Crystal Field Theory predicts that the molecule would have two unpaired electrons. The disagreement between qualitative theory (paramagnetic) and observation (diamagnetic) led to the development of models for "magnetic coupling." These improved models led to the development of new magnetic materials and new technologies.
|
|
The fry appear to be almost transparent at first, with the exception of the eyes, and do not begin to develop the 'lozenge' shape of the adult body until the differentiation of the finfold into the unpaired fins is complete (around 4–6 weeks). Once this process is complete, the fishes are ready to take sifted Daphnia. Maintenance temperature for the fry should be carefully and slowly reduced to around 25 °C once the fishes are thus recognisably miniature versions of the adults. The first signs of black colouration on the unpaired fins may take a further two weeks of more to being manifesting themselves, and it will not be until the fishes are at least 12 weeks old that they will fully represent miniature versions of the parents.
|
|
Dense shrub or thicket-forming perennial, found in chaparral plant communities. Height/spread: 30–100 cm (1m) high and wide. Stems: Stems are low and arching, with many, generally unpaired, straight, slender prickles measuring 2-12mm in length. Leaves: The leaves of Rosa minutifolia are the smallest of the genus Rosa, with the terminal leaflets measuring just 3-6mm long and wide.
|
|
Gulls begin to assemble around the colony for a few weeks prior to occupying the colony. Existing pairs re-establish their pair-bonds, and unpaired birds begin courting. Birds then move back into their territories and new males establish new territories and attempt to court females. Gulls defend their territories from rivals of both sexes through calls and aerial attacks.
|
|
Banwell and McCash, p69 Nitric oxide, NO, is a special case as the molecule is paramagnetic, with one unpaired electron. Coupling of the electron spin angular momentum with the molecular vibration causes lambda-doublingAnother example of lambda-doubling is found in the energy levels of the hydroxyl radical. with calculated harmonic frequencies of 1904.03 and 1903.68 cm−1. Rotational levels are also split.
|
|
Nops have subsegmeted tarsi, as well as two other leg characters often found in nopine genera: a ventral translucent keel on the anterior metatarsi and a translucent membrane between the anterior metatarsi and tarsi. These spiders can be distinguished from similar genera with these modifications by their elongated unpaired claw on the anterior legs, extending dorsally between the paired claws.
|
|
Nucleotides are added at the open ends by terminal deoxynucleotidyl transferase (TdT). This occurs until there are complementary sequences at which point the opposite strands will pair up. Exonucleases then remove the unpaired nucleotides, and ligases fill in the gaps. This creates a junction between each joined segment, containing an unspecified number of nucleotide additions, flanked by a 2-residue palindromic sequence.
|
|
An unpaired male in healthy condition will sing advertisement songs directed at particularly nothing. He will begin singing with his head level, and bill opening and closing and a slight hint of bobbing. But soon his body will become motionless. However, when a female is near-by, the male may preface his display by flying about with a bit of nesting material.
|
|
Aqueous solutions of ferrates are pink when dilute, and deep red or purple at higher concentrations. The ferrate ion is a stronger oxidizing agent than permanganate, and will oxidize chromium(III) to dichromate, and ammonia to molecular nitrogen. The ferrate(VI) ion has two unpaired electrons, and is thus paramagnetic. It has a tetrahedral molecular geometry, isostructural with the chromate and permanganate ions.
|
|
The Grevilleoideae grow as trees, shrubs, or subshrubs. They are highly variable, making a simple, diagnostic identification key for the subfamily essentially impossible to provide. One common and fairly diagnostic characteristic is the occurrence of flowers in pairs that share a common bract. However, a few Grevilleoideae taxa do not have this property, having solitary flowers or inflorescences of unpaired flowers.
|
|
The unpaired umbilical vein carries oxygen and nutrient rich blood derived from fetal-maternal blood exchange at the chorionic villi. More than two-thirds of fetal hepatic circulation is via the main portal vein, while the remainder is shunted from the left portal vein via the ductus venosus to the inferior vena cava, eventually being delivered to the fetal right atrium.
|
|
In accordance with Hund's rules, they remain unpaired and spin-parallel and account for the paramagnetism of molecular oxygen. These half-filled orbitals are antibonding in character, reducing the overall bond order of the molecule to 2 from a maximum value of 3 (e.g., dinitrogen), which occurs when these antibonding orbitals remain fully unoccupied. The molecular term symbol for triplet oxygen is 3Σ.
|
|
Some zirconium halides (ZrCl3, ZrBr3, and ZrI3) have structures similar to HfI3. They also have similar space group (P63/mcm) and hexagonal structure with 2 molecules in the cell. The magnetic susceptibility of zirconium trichloride suggests metal- metal interactions of the unpaired electron on each Zr(III) center. The magnetic moment of ZrCl3 (0.4 BM) indicates considerable overlap of metal orbitals.
|
|
Up-lines are not written with a heavy line for speed reasons. All in all, shorthand reduces words to syllables, where whole syllables are written at once. Beside the basic system there is a huge set of static unpaired abbreviations. For example, the German form of to be, 3rd person singular indicative present tense “ist” is a single dot on the upper line.
|
|
In contrast, a high-spin d8 transition metal complex is usually octahedral, substitutionally labile, with two unpaired electrons. Jahn-Teller effect is the geometrical distortion of non-linear molecules under certain situations. Any non-linear molecule with a degenerate electronic ground state will undergo a geometrical distortion that removes that degeneracy. This has the effect of lowering the overall energy.
|
|
Daffodil cichlids are graceful fish with bodies that are elongated with a continuous dorsal fin. The tail fin is lyre-shaped and they develop long flowing filaments on all unpaired fins. They usually reach up to about in length, but can sometimes get a bit bigger in the aquarium reaching up to . They can live 8 – 10 years with proper care.
|
|
The above picture is a generalization as it pertains to materials with an extended lattice rather than a molecular structure. Molecular structure can also lead to localization of electrons. Although there are usually energetic reasons why a molecular structure results such that it does not exhibit partly filled orbitals (i.e. unpaired spins), some non-closed shell moieties do occur in nature.
|
|
Eu(fod)3 consists of three bidentate acetylacetonate ligands bound to a Eu(III) center. This metal atom has an electron configuration of f6. The six electrons are unpaired—each in a different singly-occupied f-orbital—which makes the molecule highly paramagnetic. The complex is a Lewis acid, being capable of expanding its coordination number of six to eight.
|
|
Gondek LP, Tiu R, O'Keefe CL, Sekeres MA, Theil KS, Maciejewski JP. Chromosomal lesions and uniparental disomy detected by SNP arrays in MDS, MDS/MPD, and MDS-derived AML. Blood. 2008 Feb 1;111(3):1534–42.Beroukhim R, Lin M, Park Y, Hao K, Zhao X, Garraway LA, et al. Inferring loss-of-heterozygosity from unpaired tumors using high-density oligonucleotide SNP arrays.
|
|
The general structure of an organic peroxide The general structure of a perester Organic peroxides are organic compounds containing the peroxide functional group (ROOR′). If the R′ is hydrogen, the compounds are called organic hydroperoxides. Peresters have general structure RC(O)OOR. The O−O bond easily breaks, producing free radicals of the form RO• (the dot represents an unpaired electron).
|
|
Lewis electron configuration of superoxide. The six outer-shell electrons of each oxygen atom are shown in black; one electron pair is shared (middle); the unpaired electron is shown in the upper-left; and the additional electron conferring a negative charge is shown in red. A superoxide is a compound that contains the superoxide ion, which has the chemical formula .Hayyan m.
|
|
When there is an intruder, the russet-crowned motmot holds a leaf in its beak to display combative behaviour before chasing or fighting the intruder. This territorial behaviour is performed year-round during the breeding and non-breeding season. Both paired and unpaired males and females defend their territory. Mating pairs will react differently towards male intruders and female intruders.
|
|
The force of the interaction tends to push the atom out of the magnetic field. By convention diamagnetic susceptibility is given a negative sign. Very frequently diamagnetic atoms have no unpaired electrons ie each electron is paired with another electron in the same atomic orbital. The moments of the two electrons cancel each other out, so the atom has no net magnetic moment.
|
|
Diamagnetism is a universal property of chemical compounds, because all chemical compounds contain electron pairs. A compound in which there are no unpaired electrons is said to be diamagnetic. The effect is weak because it depends on the magnitude of the induced magnetic moment. It depends on the number of electron pairs and the chemical nature of the atoms to which they belong.
|
|
The "common" oxidation states of these elements typically differ by two instead of one. For example, compounds of gallium in oxidation states +1 and +3 exist in which there is a single gallium atom. No compound of Ga(II) is known: any such compound would have an unpaired electron and would behave as a free radical and be destroyed rapidly.
|
|
Crystal structure of MSH2:MSH3 heterodimer in complex with DNA (). MSH2 and MSH3 bind to form MutSβ. This crystal structure shows MutSβ bound to DNA containing an insertion loop of three unpaired nucleotides. DNA mismatch repair protein, MutS Homolog 3 (MSH3) is a human homologue of the bacterial mismatch repair protein MutS that participates in the mismatch repair (MMR) system.
|
|
Bedotia species are all under 10 centimetres (4 in) SL, extremely colorful, elongate, and somewhat laterally compressed atherinoid fishes that exhibit varying degrees of sexual dimorphism. Except for coloration and pigmentation, Bedotia are morphologically conservative fishes. All Bedotia are sexually dimorphic, with males exhibiting larger adult size, enhanced coloration and pigmentation, as well as pronounced development of the unpaired fins.
|
|
These spiders have subsegmented tarsi similar to the other nopine genera, Nops, Tarsonops, and Orthonops. They can easily be distinguished from other nopines by their unique eye pattern: two distinctly separate rows of four eyes each. They can sometimes be further distinguished by the claws on leg tarsi. In most spiders with three claws, the unpaired claw is smaller than the other two.
|
|
The basic principles are similar but the instrumentation, data analysis, and detailed theory are significantly different. Moreover, there is a much smaller number of molecules and materials with unpaired electron spins that exhibit ESR (or electron paramagnetic resonance (EPR)) absorption than those that have NMR absorption spectra. On the other hand, ESR has much higher signal per spin than NMR does.
|
|
An RNA stem-loop secondary structure The secondary structure of nucleic acid molecules can often be uniquely decomposed into stems and loops. The stem-loop structure (also often referred to as an "hairpin"), in which a base- paired helix ends in a short unpaired loop, is extremely common and is a building block for larger structural motifs such as cloverleaf structures, which are four-helix junctions such as those found in transfer RNA. Internal loops (a short series of unpaired bases in a longer paired helix) and bulges (regions in which one strand of a helix has "extra" inserted bases with no counterparts in the opposite strand) are also frequent. There are many secondary structure elements of functional importance to biological RNA's; some famous examples are the Rho-independent terminator stem-loops and the tRNA cloverleaf.
|
|
N. Stromberg During amplexus in newts, males will typically show the behaviour of tail fanning and chin rubbing which is thought to prompt the mating receptivity of the female newt. Studies have shown that male newts who have deeper tail-fins have better control of females during amplexus and are also more successful in catching the females for amplexus. Additionally, it has been found that the probability of a male newt who has a deeper tail-fin to achieve amplexus is greater than those newts who do not contain a deeper tail-fin, as male newts tend to use their tails during male-male competition. When a male newt, who is unpaired, encounters a female and male newt engaged in amplexus, the unpaired newt will try to displace the paired male newt by using wrestling tactics.
|
|
Functional groups contained within the spin label determine their specificity. At neutral pH, protein thiol groups specifically react with the functional groups methanethiosulfonate, maleimide, and iodoacetamide, creating a covalent bond with the amino acid Cys. Spin labels are a unique molecular reporter, in that they are paramagnetic (contain an unpaired electron). Spin labels were first synthesized in the laboratory of H. M. McConnell in 1965.
|
|
There is a double row of small tube feet along the ventral surface and a single row of larger tube feet on each side of the body. The skin is soft and pliable and the colour is violet in preserved specimens. The larva has ten tentacles and is transparent with a reddish hue at the anterior end. It has an unpaired gelatinous dorsal appendage.
|
|
In Drosophila melanogaster, miR-279 influences circadian rhythms by regulating the expression of the cytokine unpaired (upd). Flies with mutant alleles affecting miR-279 fail to maintain robust rest/activity rhythms when housed in free- running conditions (i.e. when they are maintained in the absence of any external cues). Given this phenotype, one might expect miR-279 to directly regulate clock genes within the core-clock neurons.
|
|
Engelhardia serrata is a tree growing up to 12 m tall. The leaves are pinnate, rarely unpaired, and 150–250 mm long. The petiole is 10–20 mm long and hairy; the rhachis is also hairy. The 6 to 14 leaflets are seated or short stalked, the blade is elliptic to elliptic-lanceolate, 60–130 mm long and 25–45 mm wide, the underside is hairy.
|
|
The first d electron count (special version of electron configuration) with the possibility of holding a high spin or low spin state is octahedral d4 since it has more than the 3 electrons to fill the non-bonding d orbitals according to ligand field theory or the stabilized d orbitals according to crystal field splitting. ;d4: :Octahedral high-spin: 4 unpaired electrons, paramagnetic, substitutionally labile.
|
|
This kinetic barrier prevents life from bursting into flames at room temperature. Electronic spin states are more complex for transition metals. To understand the reactivity of transition metals, it is essential to understand the concept of d electron configuration as well as high-spin and low-spin configuration. For example, a low-spin d8 transition metal complex is usually square planar substitutionally inert with no unpaired electrons.
|
|
45,X karyotype, showing an unpaired X at the lower right Turner syndrome may be diagnosed by amniocentesis or chorionic villus sampling during pregnancy. Usually, fetuses with Turner syndrome can be identified by abnormal ultrasound findings (i.e., heart defect, kidney abnormality, cystic hygroma, ascites). In a study of 19 European registries, 67.2% of prenatally diagnosed cases of Turner syndrome were detected by abnormalities on ultrasound.
|
|
Koopmans' theorem is also applicable to open-shell systems. It was previously believed that this was only in the case for removing the unpaired electron, but the validity of Koopmans’ theorem for ROHF in general has been proven provided that the correct orbital energies are used. The spin up (alpha) and spin down (beta) orbital energies do not necessarily have to be the same.
|
|
The breeding season varies depending on location, but normally takes place during autumn or spring. In South Africa, breeding occurs in early July. During the breeding season, unpaired male aardwolves search their own territory, as well as others, for a female to mate with. Dominant males also mate opportunistically with the females of less dominant neighboring aardwolves, which can result in conflict between rival males.
|
|
Variegated variety with flowers. Fruit capsules Growing to , it is a climbing plant that has compound, evergreen leaves. The mainly opposite, sometimes three-part whorled leaves are unpaired pinnate and about 12 to 17 cm long with a 2 to 4 cm long petiole. They consist of four to seven leaflets that are 4.5 to 6 inches long and 1.5 to 3 inches wide.
|
|
After earning her PhD degree Heutz worked as a postdoctoral research fellow on solar cells at Imperial College London. She moved to University College London in 2004, where she started work on magnetic biosensors. Heutz joined Imperial College London in 2007 as a Royal Society Dorothy Hodgkin research fellow. Heutz specialises in the use of electron paramagnetic resonance (EPR) to monitor unpaired electrons within materials.
|
|
Social groups are made up of a monogamous pair and one or two of its young. A count of ten groups in Vichada yielded an average of 3.5 per group. Occasionally groups of five are seen and unpaired individuals ("floaters") can also be detected from time to time. Second year youngsters usually leave the group, although they may make it into the third year before leaving.
|
|
Organic Chemistry John McMurry 2nd ed. 1988 Each species can be presented by two resonance structures with the charge or unpaired electron distributed at both 1,3 positions. :Resonance structure of the allyl anion In terms of MO theory, the MO diagram has three molecular orbitals: the first one bonding, the second one non-bonding and the higher energy orbital is antibonding.Organic Chemistry 4th Ed. Morisson & Boyd 1988.
|
|
Chromium(III) acetylacetonate, Cr(acac)3, is a typical octahedral complex containing three acac− ligands. Like most such compounds, it is highly soluble in nonpolar organic solvents. This particular complex, which has a three unpaired electrons, is used as a spin relaxation agent to improve the sensitivity in quantitative carbon-13 NMR spectroscopy. Chromium(II) acetylacetonate is a highly oxygen-sensitive, light brown compound.
|
|
The tyrosinyl radical participates in the catalytic cycle: 1e-oxidation is effected by the Cu(II/I) couple and the 1e oxidation is effected by the tyrosyl radical, giving an overall 2e change. The radical abstraction is fast. Anti-ferromagnetic coupling between the unpaired spins of the tyrosine radical ligand and the d9 CuII center gives rise to the diamagnetic ground state, consistent with synthetic models.
|
|
The effect is detected by NMR spectroscopy, usually using 1H NMR spectrum, as enhanced absorption or emission signals ("negative peaks"). The effect arises when unpaired electrons (radicals) are generated during a chemical reaction. Because the magnetic moment of an electron is more than 600x that of a proton, the spins of many protons are polarized beyond the usual thermal Boltzmann distribution. The CIDNP experiment is conducted within the NMR tube.
|
|
Since then, a variety of nitroxide spin labels have enjoyed widespread use for the study of macromolecular structure and dynamics because of their stability and simple EPR signal. The nitroxyl radical (N-O) is usually incorporated into a heterocyclic ring (e.g. pyrrolidine), and the unpaired electron is predominantly localized to the N-O bond. Once incorporated into the protein, a spin label's motions are dictated by its local environment.
|
|
Be2, an opening that he has never seen before, but at the end still won the thrilling game against Andrew Greet of Scotland. The issue with the incomplete pairing was handed down from the first to the second round and 14 African teams remained unpaired, meaning that the total number of teams actually playing was 166 instead of 180 as expected, which was 10 less than at the previous Chess Olympiad.
|
|
Journal of the American Chemical Society (1962), 84 3968-70.Eaton, D. R.; Josey, A. D.; Benson, R. E.; Phillips, W. D.; Cairns, T. L. Unpaired electron distribution in π-systems. Journal of the American Chemical Society (1962), 84 4100-6.Eaton, D. R.; Phillips, W. D.; Caldwell, D. J. Configurations and magnetic properties of the nickel(II) aminotroponeimineates. Journal of the American Chemical Society (1963), 85 397-406.
|
|
"Phase Diagrams of the Elements", David A. Young, UCRL-51902 "Prepared for the U.S. Energy Research & Development Administration under contract No. W-7405-Eng-48". Praseodymium, like all of the lanthanides (except lanthanum, ytterbium, and lutetium, which have no unpaired 4f electrons), is paramagnetic at room temperature. Unlike some other rare-earth metals, which show antiferromagnetic or ferromagnetic ordering at low temperatures, praseodymium is paramagnetic at all temperatures above 1 K.
|
|
In the context of atomic orbitals, an open shell is a valence shell which is not completely filled with electrons or that has not given all of its valence electrons through chemical bonds with other atoms or molecules during a chemical reaction. Conversely a closed shell is obtained with a completely filled valence shell. This configuration is very stable. For molecules, "open shell" signifies that there are unpaired electrons.
|
|
Majorana bound states can also be realized in quantum error correcting codes. This is done by creating so called 'twist defects' in codes such as the Toric code which carry unpaired Majorana modes. The braiding of Majoranas realized in such a way forms a projective representation of the braid group. Such a realization of Majoranas would allow them to be used to store and process quantum information within a quantum computation.
|
|
The haploid gametophyte has n unpaired chromosomes, i.e. half the number of the sporophyte. The gametophyte of ferns is a free-living organism, whereas the gametophyte of the gymnosperms and angiosperms is dependent on the sporophyte. The life cycle of a typical fern proceeds as follows: # A diploid sporophyte phase produces haploid spores by meiosis (a process of cell division which reduces the number of chromosomes by a half).
|
|
Accordingly, it has higher sperm storage and makes more mating overtures towards females. A male with browner and less bright plumage or a younger male with bright plumage has a much lower success rate than a bright, older male for mating. Further, an unpaired male serves as a helper to a mated pair in feeding and care of young. After the male pairs, his bill darkens within three weeks.
|
|
The trimeric structure allows all nickel centers to achieve an octahedral coordination. The trimer is only formed if intramolecular sharing of oxygen centers between pairs of nickel centers occurs. The anhydrous complex has interesting magnetic properties. Down to about 80 K it exhibits normal paramagnetism with an effective magnetic moment of 3.2 μB, close to the spin-only moment expected of a d8 ion with two unpaired electrons.
|
|
Skewness risk plays an important role in hypothesis testing. The analysis of variance, the most common test used in hypothesis testing, assumes that the data is normally distributed. If the variables tested are not normally distributed because they are too skewed, the test cannot be used. Instead, nonparametric tests can be used, such as the Mann–Whitney test for unpaired situation or the sign test for paired situation.
|
|
Only in the genus Megaselia is the hypandrium more or less distinctly separated from the epandrium. Unpaired sclerites (ventrites) developed at the distal end of the hypandrium vary in shape. They may be flat, swollen, or other. Sclerites are always present near the base of the cerci, which may be highly developed, and converted either into a tube (anal tube) or a pair of asymmetrical large outgrowths (Phora).
|
|
It is more likely that this individual was an unpaired male or a late migrant. Brown-headed cowbirds were one of the few problematic or non-native species observed. These birds pose a risk to neotropical migrants in that their habit of laying their eggs in the nests of other species impacts the productivity of native, neotropical migrants. In June 2002, a Louisiana waterthrush was observed feeding an immature cowbird.
|
|
Males usually possess more elongated and ornate unpaired fins than females. In the case of C. arnoldi, the tail fin of the male is somewhat asymmetrical, the upper lobe being larger than the lower lobe, and this modification of the more usual symmetrical tail fin shape (tail fin symmetry is a characteristic of the majority of fishes belonging to the Actinopterygii) is linked to the reproductive activity of the species.
|
|
Some of the plexuses enlarge and form lymphatic vessels in their respective regions. Each jugular lymph sac retains at least one connection with its jugular vein, the left one developing into the superior portion of the thoracic duct. The next lymph sac to appear is the unpaired retroperitoneal lymph sac at the root of the mesentery of the intestine. It develops from the primitive vena cava and mesonephric veins.
|
|
TDtv combines IPWireless commercial UMTS TD-CDMA solution and 3GPP Release 6 Multimedia Broadcast Multicast Service (MBMS) to deliver Mobile TV. TDtv operates in the universal unpaired 3G spectrum bands that are available worldwide at 1900 MHz and 2100 MHz. It allows UMTS operators to fully utilize their existing spectrum and base stations to offer mobile TV and multimedia packages without affecting other voice and data 3G services.
|
|
Homolytic bond cleavage is a process where the electron pair comprising a bond is split, causing the bond to break. This is denoted by two single barbed curved arrows pointing away from the bond. The consequence of this process is the retention of a single unpaired electron on each of the atoms that were formerly joined by a bond. These single electron species are known as free radicals.
|
|
The parametric alternative to the Scheirer–Ray–Hare test is multi-factorial ANOVA, which requires a normal distribution of data within the samples. The Kruskal–Wallis test, from which the Scheirer–Ray–Hare test is derived, serves in contrast to this to investigate the influence of exactly one factor on the measured variable. A non-parametric test comparing exactly two unpaired samples is the Wilcoxon–Mann–Whitney test.
|
|
The card can still be used to view non-premium channels such as Sky1 but will display an error message when attempting to watch a movie channel or sports channel with an unpaired box and card combination. A card can be 're-paired' in some instances such as STB replacement or multiroom relocation, however this must be initiated by Sky and cannot be completed by an end-user.
|
|
Microwave radiation is used in electron paramagnetic resonance (EPR or ESR) spectroscopy, typically in the X-band region (~9 GHz) in conjunction typically with magnetic fields of 0.3 T. This technique provides information on unpaired electrons in chemical systems, such as free radicals or transition metal ions such as Cu(II). Microwave radiation is also used to perform rotational spectroscopy and can be combined with electrochemistry as in microwave enhanced electrochemistry.
|
|
It makes the animal appear much larger and more of a threat to the attacker. The black eyespots are also a distinct feature for species discrimination of the European mantis. Another unique feature of M. religiosa is its midline metathoracic ear (see Ultrasound avoidance). This “tympanal auditory organ” is an unpaired structure found on the ventral side of the animal on the metathorax between the third pair of legs.
|
|
Clark's grebes appear to have semi-monogamous behavior, staying with a single mate, but possibly only for a single season as far as known. Unpaired males far outnumber the females. Males, while they stay with their mate until at least a few weeks after the hatching of their young, will have several sexual partners in their lifetime. It is less known if pairs will eventually mate again in the future.
|
|
Effectively, this results in a higher concentration of drug to be in contact with the tumor for a longer period of time. Park et al. conceptualized carcinogenesis of hepatocellular carcinoma (HCC) as a multistep process involving parenchymal arterialization, sinusoidal capillarization, and development of unpaired arteries (a vital component of tumor angiogenesis). All these events lead to a gradual shift in tumor blood supply from portal to arterial circulation.
|
|
Phosphorus monoxide is a free radical with phosphorus double bonded to oxygen with phosphorus having an unpaired valence electron. The bond order is about 1.8. The P=O bond in PO has a dissociation energy of 6.4 eV. The bond length of the PO double bond is 1.476 Å, and free PO shows an infrared vibrational frequency of 1220 cm−1 due to the stretching of the bond.
|
|
Spectrum of the blue flame from a butane torch showing excited molecular radical band emission and Swan bands A familiar radical reaction is combustion. The oxygen molecule is a stable diradical, best represented by ·O-O·. Because spins of the electrons are parallel, this molecule is stable. While the ground state of oxygen is this unreactive spin- unpaired (triplet) diradical, an extremely reactive spin-paired (singlet) state is available.
|
|
The magnitude of the paramagnetism is expressed as an effective magnetic moment, μeff. For first- row transition metals the magnitude of μeff is, to a first approximation, a simple function of the number of unpaired electrons, the spin-only formula. In general, spin-orbit coupling causes μeff to deviate from the spin-only formula. For the heavier transition metals, lanthanides and actinides, spin- orbit coupling cannot be ignored.
|
|
Variation of magnetic susceptibility with temperature A metal ion with a single unpaired electron, such as Cu2+, in a coordination complex provides the simplest illustration of the mechanism of paramagnetism. The individual metal ions are kept far apart by the ligands, so that there is no magnetic interaction between them. The system is said to be magnetically dilute. The magnetic dipoles of the atoms point in random directions.
|
|
1099–1011 :Fe(II)Hb + O2 [Fe(II)Hb]O2 (low-spin) This information has an important bearing on research to find artificial oxygen carriers. Compounds of gallium(II) were unknown until quite recently. As the atomic number of gallium is an odd number (31), Ga2+ should have an unpaired electron. It was assumed that it would act as a free radical and have a very short lifetime.
|
|
Additionally, parasitised nests often have one more egg than non-parasitised nests. The female may follow a mixed strategy with relation to brood parasitism (being parasitic in addition to incubating its own clutch). From about 32% to 58% of females do this, and almost all (about 96%) lay parasitic eggs before incubating their clutch. Unpaired females sometimes lay parasitic eggs, but paired females do not rely solely on parasitism.
|
|
Milan Lazár (1989), Free radicals in chemistry and biology. CRC Press. When the methylene molecule is in its state of lowest energy, the unpaired valence electrons are in separate atomic orbitals with independent spins, a configuration known as triplet state. Methylene may gain an electron yielding a monovalent anion methanidyl (), which can be obtained as the trimethylammonium (()4) salt by the reaction of phenyl sodium () with trimethylammonium bromide (()4).
|
|
According to J. Siegel (2005), sleep deprivation results in the build-up of free radicals and superoxides in the brain. Free radicals are oxidizing agents that have one unpaired electron, making them highly reactive. These free radicals interact with electrons of biomolecules and damage cells. In slow-wave sleep, the decreased rate of metabolism reduces the creation of oxygen byproducts, thereby allowing the existing radical species to clear.
|
|
An empirical correction is then added to account for factors not considered above. This is called the higher level correction (HC) and is given by -0.00481 x (number of valence electrons) -0.00019 x (number of unpaired valence electrons). The two numbers are obtained calibrating the results against the experimental results for a set of molecules. The scaled ZPVE and the HLC are added to give the final energy.
|
|
In 1932 Chadwick realized that radiation that had been observed by Walther Bothe, Herbert Becker, Irène and Frédéric Joliot-Curie was actually due to a neutral particle of about the same mass as the proton, that he called the neutron (following a suggestion from Rutherford about the need for such a particle). In the same year Dmitri Ivanenko suggested that there were no electrons in the nucleus — only protons and neutrons — and that neutrons were spin particles, which explained the mass not due to protons. The neutron spin immediately solved the problem of the spin of nitrogen-14, as the one unpaired proton and one unpaired neutron in this model each contributed a spin of in the same direction, giving a final total spin of 1. With the discovery of the neutron, scientists could at last calculate what fraction of binding energy each nucleus had, by comparing the nuclear mass with that of the protons and neutrons which composed it.
|
|
Unwin and Benton interpreted them as a single, unpaired row of modified scales that run along the dorsal midline. Jones et al. interpreted them as two paired rows of structures that are anatomically very much like feathers, and which are in positions like those of birds' spinal feather tracts. Feather-development expert Richard Prum (and also Reisz and Sues) see the structures as anatomically very different from feathers, and thinks they are elongate, ribbonlike scales.
|
|
The number and quality of nests appear to serve a direct benefit to females (direct benefit hypothesis), as it provides protection from predation, as well as access to food resources, as good nest quality can be indicated by access to prey (i.e. small mammals). Female boreal owls’ reproductive success can decline in polyterritorial polygamous situations, as females are unable to discriminate previously paired and unpaired males (also known as the deception hypothesis).
|
|
Like all cells, somatic cells contain DNA arranged in chromosomes. If a somatic cell contains chromosomes arranged in pairs, it is called diploid and the organism is called a diploid organism. (The gametes of diploid organisms contain only single unpaired chromosomes and are called haploid.) Each pair of chromosomes comprises one chromosome inherited from the father and one inherited from the mother. For example, in humans, somatic cells contain 46 chromosomes organized into 23 pairs.
|
|
Arterial supply to the midgut is from the superior mesenteric artery, an unpaired branch of the aorta. Venous drainage is to the portal venous system. Lymph from the midgut drains to prevertebral superior mesenteric nodes located at the origin of the superior mesenteric artery from the aorta. Portal drainage carries all non-lipid nutrients from digestion to the liver for processing and detoxification, while lymphatic drainage carries fatty chyle to the cisterna chyli.
|
|
This is realized as zero field splitting and exchange coupling, and can be large in magnitude. # The magnetic moment of a nucleus with a non-zero nuclear spin will affect any unpaired electrons associated with that atom. This leads to the phenomenon of hyperfine coupling, analogous to J-coupling in NMR, splitting the EPR resonance signal into doublets, triplets and so forth. Additional smaller splittings from nearby nuclei is sometimes termed "superhyperfine" coupling.
|
|
The boiling point (82 K) and melting point (68 K) are very similar to those of N2 (77 K and 63 K, respectively). The bond-dissociation energy of 1072 kJ/mol is stronger than that of N2 (942 kJ/mol) and represents the strongest chemical bond known.Common Bond Energies (D) and Bond Lengths (r). wiredchemist.com The ground electronic state of carbon monoxide is a singlet state since there are no unpaired electrons.
|
|
It is important to note that there are simple and archetypal molecular systems for which a Lewis description, at least in unmodified form, is misleading or inaccurate. Notably, the naive drawing of Lewis structures for molecules known experimentally to contain unpaired electrons (e.g., O2, NO, and ClO2) leads to incorrect inferences of bond orders, bond lengths, and/or magnetic properties. A simple Lewis model also does not account for the phenomenon of aromaticity.
|
|
The thoracic segments are obliquely tilted backwards as in dragonflies, so that the raptorial forelegs are shifted forwards. All legs have a strongly prolonged and free coxal segment. The forelegs are developed as subchelate raptorial devices with a single-segmented tarsus with an unpaired claw. Most likely the abdomen was provided with three caudal filaments (two lateral cerci and the median epiproct) as in modern mayflies and their Permian stem group representatives (Permoplectoptera, e.g. Protereismatidae).
|
|
Tarpon swimming One of the unique features of Megalops is the swim bladder, which functions as a respiratory pseudo-organ. This gas structure can be used for buoyancy, as an accessory respiratory organ, or both. In Megalops, this unpaired air-holding structure arises dorsally from the posterior pharynx. Megalops uses the swim bladder as a respiratory organ and the respiratory surface is coated with blood capillaries with a thin epithelium over the top.
|
|
There is normally a single clutch each year, but there are records of birds attempting to breed in the autumn. In autumn, the young birds of the summer collect into large flocks together with unpaired birds of previous seasons, often in company with jackdaws. It is during this time of year that spectacular aerial displays are performed by the birds. The species is monogamous, with the adults forming long-term pair bonds.
|
|
Limpkin chicks with parents Nests may be built in a wide variety of places – on the ground, in dense floating vegetation, in bushes, or at any height in trees. They are bulky structures of rushes, sticks, or other materials. Nest building is undertaken by the male initially, which constructs the nest in his territory prior to pair-bond formation. Unpaired females visit a number of territories before settling on a male with which to breed.
|
|
As a result, when filling up atomic orbitals, the maximum number of unpaired electrons (and hence maximum total spin state) is assured. The valence orbitals of the oxygen atom (sides of diagram) and the dioxygen molecule (middle) in the ground state. In both atom and molecule, the electrons in singly occupied orbitals have their spins parallel. For example, in the oxygen atom, the 2p4 subshell arranges its electrons as [↑↓] [↑] [↑] rather than [↑↓] [↑] [↓] or [↑↓] [↑↓][ ].
|
|
Nucleotides which are constrained (usually by base-pairing) show less adduct formation than nucleotides which are unpaired. Adduct formation is quantified for each nucleotide in a given RNA by extension of a complementary DNA primer with reverse transcriptase and comparison of the resulting fragments with those from an unmodified control. SHAPE therefore reports on RNA structure at the individual nucleotide level. This data can be used as input to generate highly accurate secondary structure models.
|
|
The opened ends are held in place by other proteins in the complex. Another enzyme, a U-specific exoribonuclease, removes the unpaired Us. After editing has made mRNA complementary to gRNA, an RNA ligase rejoins the ends of the edited mRNA transcript. As a consequence, the editosome can edit only in a 3' to 5' direction along the primary RNA transcript. The complex can act on only a single guide RNA at a time.
|
|
Gaffney et al. united Kayentachelys with cryptodiran taxa based upon featured of the palate and braincase. Sterli and Joyce (2007) emended the diagnosis of Kayentachelys using a unique combination of ancestral and derived cranial character states, including prefrontals which do not contact one another at the midline, the absence of lacrimals, frontals which contribute to the orbit, an unpaired vomer, pterygoid teeth, the absence of palatal teeth, and a retroarticular process, among many other features.
|
|
Subatomic particles have the quantum mechanical property of spin. Certain nuclei such as 1H (protons), 2H, 3He, 23Na or 31P, have a non–zero spin and therefore a magnetic moment. In the case of the so-called spin- nuclei, such as 1H, there are two spin states, sometimes referred to as up and down. Nuclei such as 12C have no unpaired neutrons or protons, and no net spin; however, the isotope 13C does.
|
|
Biophosphorescence is similar to biofluorescence in its requirement of light at specified wavelengths as a provider of excitation energy. The difference here lies in the relative stability of the energized electron. Unlike with biofluorescence, here the electron retains stability in the forbidden triplet state (unpaired spins), with a longer delay in emitting light resulting in the effect that it continues to “glow-in-the-dark” even long after the stimulating light source has been removed.
|
|
This polarizing mechanism is optimal when the exciting microwave frequency shifts up or down by the nuclear Larmor frequency from the electron Larmor frequency in the discussed two-spin system. The direction of frequency shifts corresponds to the sign of DNP enhancements. Solid effect exist in most cases but is more easily observed if the linewidth of the EPR spectrum of involved unpaired electrons is smaller than the nuclear Larmor frequency of the corresponding nuclei.
|
|
HLLE begins as small pits of receding epithelium (skin) around the fish's head and/or lateral line, and sometimes onto the unpaired fins. Rarely fatal, it does cause disfigurement, making the fish less suitable for public aquarium display. At least 20 families of fish have been identified as having developed HLLE in captivity. Not all species of fish show the same symptoms, and do not always develop lesions to the same degree.
|
|
The male powerful owl's song is an impressive low, rather mournful-sounding and far-carrying double-hoot, whoo- hooo, each note lasting a few seconds at least, broken up by a brief silence and the second note being usually higher pitched than the first. The female has a similar call but has a higher pitched voice. Duets are frequently heard at the onset of breeding. Unpaired males frequently call much more regularly than paired ones.
|
|
These fish have a light-colored tan body washed with hints of yellow and bluish-purple spots. The yellow is stronger along the upper portion of the body and onto the dorsal fin, and around the base of the pectoral fin. There are two vertical crescent-shaped bars just behind the eye highlighted with a bit of blue. The dorsal fin is lyre-shaped and they develop long flowing filaments on all unpaired fins.
|
|
Most cells in the human body have 23 pairs of chromosomes, or a total of 46 chromosomes. (The sperm and egg, or gametes, each have 23 unpaired chromosomes, and red blood cells have no nucleus and no chromosomes). One copy of each pair is inherited from the mother and the other copy is inherited from the father. The first 22 pairs of chromosomes (called autosomes) are numbered from 1 to 22, from largest to smallest.
|
|
Each molybdenum has local octahedral symmetry and two chlorides bridge between the molybdenum centers. A similar structure is also found for the pentachlorides of W, Nb and Ta. In the gas phase and partly in solution, the dimers partially dissociates to give a monomeric pentahalide. The monomer is paramagnetic, with one unpaired electron per Mo center, reflecting the fact that the formal oxidation state is +5, leaving one valence electron on the metal center.
|
|
6554-6558 In the field of physical chemistry his work was directed on electron spin resonance measurements of phosphoranyl radicals with phosphorus in different geometries as the tetrahedral and the trigonal bipyramidal configuration with the unpaired electron in an equatorial or axial orientation.Aagaard, O.M. et al. (1990) "Intermolecular effects on the radiogenic formation of electron- capture phosphorus-centered Journalradicals A single-crystal ESR study of diastereoisomeric precursors", Journal of the American Chemical Society, Vol.
|
|
EPR spectrum of the CH3• radical MSTL spin-label Very few compounds of main group elements are paramagnetic. Notable examples include: oxygen, O2; nitric oxide, NO; nitrogen dioxide, NO2 and chlorine dioxide, ClO2. In organic chemistry, compounds with an unpaired electron are said to be free radicals. Free radicals, with some exceptions, are short-lived because one free radical will react rapidly with another, so their magnetic properties are difficult to study.
|
|
In the presence of more than one unpaired electron, the electrons mutually interact to give rise to two or more energy states. Zero field splitting refers to this lifting of degeneracy even in the absence of a magnetic field. ZFS is responsible for many effects related to the magnetic properties of materials, as manifested in their electron spin resonance spectra and magnetism. The classic case for ZFS is the spin triplet, i.e.
|
|
Intraspecific brood parasites are common in common starling nests. Female "floaters" (unpaired females during the breeding season) present in colonies often lay eggs in another pair's nest. Fledglings have also been reported to invade their own or neighbouring nests and evict a new brood. Common starling nests have a 48% to 79% rate of successful fledging, although only 20% of nestlings survive to breeding age; the adult survival rate is closer to 60%.
|
|
Then, Jake Schaefer and Ed Stejskal demonstrated the powerful use of cross polarization under MAS conditions (CP- MAS) and proton decoupling, which is now routinely employed to measure high resolution spectra of low-abundance and low-sensitivity nuclei, such as carbon-13, silicon-29, or nitrogen-15, in solids. Significant further signal enhancement can be achieved by dynamic nuclear polarization from unpaired electrons to the nuclei, usually at temperatures near 110 K.
|
|
Normally the best starting hand in Razz is A-2-3. A general strategy in a full-ring game is to only play unpaired cards none of them higher than 8s.Poker-Strategy.org: Razz poker Players want to avoid making pairs and should evaluate other door cards in relation to the strength of their hand. For instance, Jane holds 3-4-5 and sees four "dead" door cards of 3-4-4-5 behind her.
|
|
In these cases, the magnetization arises from the electrons' orbital motions, which can be understood classically as follows: This description is meant only as a heuristic; the Bohr-van Leeuwen theorem shows that diamagnetism is impossible according to classical physics, and that a proper understanding requires a quantum-mechanical description. All materials undergo this orbital response. However, in paramagnetic and ferromagnetic substances, the diamagnetic effect is overwhelmed by the much stronger effects caused by the unpaired electrons.
|
|
The parasphenoid is a bone which can be found in the cranium of many vertebrates. It is an unpaired dermal bone which lies at the midline of the roof of the mouth. In many reptiles (including birds), it fuses to the endochondral (cartilage-derived) basisphenoid bone of the lower braincase, forming a bone known as the parabasisphenoid. Early mammals have a small parasphenoid, but for the most part its function has been replaced by the vomer bone.
|
|
According to this theory a covalent bond is formed between two atoms by the overlap of half filled valence atomic orbitals of each atom containing one unpaired electron. A valence bond structure is similar to a Lewis structure, but where a single Lewis structure cannot be written, several valence bond structures are used. Each of these VB structures represents a specific Lewis structure. This combination of valence bond structures is the main point of resonance theory.
|
|
Though each type of synthesis is very different, they do share some features. Nucleotides that have been joined to form polynucleotides can act as a DNA template for one form of DNA synthesis - PCR - to occur. DNA replication also works by using a DNA template, the DNA double helix unwinds during replication, exposing unpaired bases for new nucleotides to hydrogen bond to. Gene synthesis, however, does not require a DNA template and genes are assembled de novo.
|
|
The search process induces stretching of the DNA duplex, which enhances sequence complementarity recognition (a mechanism termed conformational proofreading). The reaction initiates the exchange of strands between two recombining DNA double helices. After the synapsis event, in the heteroduplex region a process called branch migration begins. In branch migration an unpaired region of one of the single strands displaces a paired region of the other single strand, moving the branch point without changing the total number of base pairs.
|
|
In fact, many subsequently discovered deoxyribozymes were found to contain the same catalytic core motif as 8-17, including the previously discovered Mg5, suggesting that this motif represents the "simplest solution for the RNA cleavage problem". The 10-23 DNAzyme contains a 15-nucleotide catalytic core that is flanked by two substrate recognition domains. This DNAzyme cleaves complementary RNAs efficiently in a sequence specific manner between an unpaired purine and a paired pyrimidine. DNAzymes targeting AU or GU vs.
|
|
Example 3. An excerpt from Danse de la fureur, pour les sept trompettes from the Quatuor pour la fin du temps. It illustrates Messiaen's use of additive rhythms—in this example the addition of unpaired semiquavers (sixteenth notes) to an underlying quaver (eighth note) pulse and the lengthening of the final quaver by addition of a dot. It illustrates the use of what Messiaen called the Boris M-shaped motif (the last five notes of the excerpt).
|
|
In the early development of the embryo, neural crest cells migrate to form the mesenchymal tissue as ectomesenchyme of the pharyngeal arches. By the end of the fourth week, the first pair of pharyngeal arches form five facial prominences or processes - an unpaired frontonasal process, paired mandibular processes and paired maxillary processes. The nose is largely formed by the fusion of these five facial prominences. The frontonasal process gives rise to the bridge of the nose.
|
|
Thus, all of the unpaired dAs present in the poly(A) tail are filled in with TTP. The hybridized molecule is locked in place when the polymerase encounters the first non-A residue and inserts the appropriate virtual terminator nucleotide. Because every DNA molecule should now have a dye attached, an image will include all molecules capable of nucleotide incorporation. Also, because the label could correspond to any base, no sequence information is obtained at this stage.
|
|
The perception of magnetic fields by migratory birds has been suggested to be light dependent. Birds move their head to detect the orientation of the magnetic field, and studies on the neural pathways have suggested that birds may be able to "see" the magnetic fields. The right eye of a migratory bird contains photoreceptive proteins called cryptochromes. Light excites these molecules to produce unpaired electrons that interact with the Earth's magnetic field, thus providing directional information.
|
|
This coupling introduces additional energy states and, in turn, multi- lined spectra. In such cases, the spacing between the EPR spectral lines indicates the degree of interaction between the unpaired electron and the perturbing nuclei. The hyperfine coupling constant of a nucleus is directly related to the spectral line spacing and, in the simplest cases, is essentially the spacing itself. Two common mechanisms by which electrons and nuclei interact are the Fermi contact interaction and by dipolar interaction.
|
|
It is thus an effective bleach and is mostly used to make hypochlorites. It explodes on heating or sparking or in the presence of ammonia gas. Chlorine dioxide (ClO2) was the first chlorine oxide to be discovered in 1811 by Humphry Davy. It is a yellow paramagnetic gas (deep-red as a solid or liquid), as expected from its having an odd number of electrons: it is stable towards dimerisation due to the delocalisation of the unpaired electron.
|
|
In the solid state, niobium(IV) chloride exists as chains of edge-sharing octahedra with alternating Nb-Nb distances of lengths 302.9 and 379.4 pm. The shorter distances correspond to Nb-Nb bonds, which result in the compound’s diamagnetism. Its structure is very similar to that of tungsten(IV) chloride. Other coordination complexes with the formula NbCl4L2, such as tetrachlorobis(tetrahydrofuran) niobium, only form monomers resulting in one unpaired electron in the dxy orbital, making the compounds paramagnetic.
|
|
The highest levels of the stratosphere are exposed to the sun's ultraviolet light. A thin layer of ozone floating high in the stratosphere protects lower levels of the atmosphere from that type of radiation. Molina theorized that photons from ultraviolet light, known to break down oxygen molecules, could also break down CFCs, releasing a number of products including chlorine atoms into the stratosphere. Chlorine atoms (Cl) are radicals: they have an unpaired electron and are very reactive.
|
|
Kethoxal causes the modification of guanine, specifically altering the N1 and the exocyclic amino group (N2) simultaneously by covalent interaction. Glyoxal, methylglyoxal, and phenylglyoxal, which all carry the key 1,2-dicarbonyl moiety, all react with free guanines similar to kethoxal, and can be used to probe unpaired guanine bases in structured RNA. Due to their chemical properties, these reagents can permeate readily into cells and can therefore be used to assay RNAs in their native cellular environments.
|
|
Furthermore, for odd–odd nuclei, there are two unpaired nucleons to be considered, as in deuterium. There is consequently a value for the nuclear magnetic moment associated with each possible l and s state combination, and the actual state of the nucleus is a superposition of these. Thus the real (measured) nuclear magnetic moment is between the values associated with the "pure" states, though it may be close to one or the other (as in deuterium).
|
|
The carrying capacity of an escalator system is typically matched to the expected peak traffic demand. For example, escalators at transit stations must be designed to cater for the peak traffic flow discharged from a train, without excessive bunching at the escalator entrance. In this regard, escalators help manage the flow of people. For example, at many airports an unpaired escalator delivers passengers to an exit, with no means for anyone entering at the exit to access the concourse.
|
|
Magnetically, α-iron is paramagnetic at high temperatures. However, as it cools to 771 °C (1044K or 1420 °F),, the Curie temperature (TC or A2), it becomes ferromagnetic. The reverse also occurs: As α-iron is heated above the Curie temperature, the random thermal agitation of the atoms exceeds the oriented magnetic moment of the unpaired electron spins and it becomes paramagnetic. In the past, the paramagnetic form of α-iron was known as Beta iron (β-Fe).
|
|
This time, the team took turns for each match, and the team had 60 seconds to find all seven matches. The first four matches the team split $200; the other three matches awarded prizes, with the grand prize being awarded for all seven matches. The unpaired locker contained the "Red Herring", which was simply a character with no match. At some point during the run (after any of the first six matches), the Red Herring's locker would be opened.
|
|
When exposed to temperatures above 45 °C, the stem-loop that base-pairs opposite the Shine-Dalgarno sequence becomes unpaired and allows the mRNA to enter the ribosome for translation to occur. Mg2+ ion concentration has also been shown to affect the stability of FourU. The most well-studied RNA thermometer is found in the rpoH gene in Escherichia coli. This thermosensor upregulates heat shock proteins under high temperatures through σ32, a specialised heat-shock sigma factor.
|
|
Stronger magnetic effects are typically only observed when d or f electrons are involved. Particularly the latter are usually strongly localized. Moreover, the size of the magnetic moment on a lanthanide atom can be quite large as it can carry up to 7 unpaired electrons in the case of gadolinium(III) (hence its use in MRI). The high magnetic moments associated with lanthanides is one reason why superstrong magnets are typically based on elements like neodymium or samarium.
|
|
The ground state of has a bond length of 121 pm and a bond energy of 498 kJ/mol. It is a colourless gas with a boiling point of . It can be condensed from air by cooling with liquid nitrogen, which has a boiling point of . Liquid oxygen is pale blue in colour, and is quite markedly paramagnetic due to the unpaired electrons; liquid oxygen contained in a flask suspended by a string is attracted to a magnet.
|
|
These are now called functional groups. For example, methyl alcohol was described as consisting of a methyl "radical" and a hydroxyl "radical". Neither are radicals in the modern chemical sense, as they are permanently bound to each other, and have no unpaired, reactive electrons; however, they can be observed as radicals in mass spectrometry when broken apart by irradiation with energetic electrons. In a modern context the first organic (carbon–containing) radical identified was triphenylmethyl radical, (C6H5)3C•.
|
|
A similar process occurs upon scattering neutron waves from the nuclei or by a coherent spin interaction with an unpaired electron. These re-emitted wave fields interfere with each other either constructively or destructively (overlapping waves either add up together to produce stronger peaks or are subtracted from each other to some degree), producing a diffraction pattern on a detector or film. The resulting wave interference pattern is the basis of diffraction analysis. This analysis is called Bragg diffraction.
|
|
For example, on the Lobalopex skull the median frontal ridge is not prominent, and the posterior contact with the nasal passage is almost flat. Where, in the Lemurosaurus fossil it is observed that it has a distinct medial frontal ridge. Another difference is that Lobalopex has a dorsal orbital margin that has not become thicker with extra layers of bone, where Lemurosaurus is pachyostosed. One similarity between the two taxa is that both skull fossils contained an unpaired vomer.
|
|
He considered protons and neutrons to be different quantum states of the same particle, i.e., nucleons distinguished by the value of their nuclear isospin quantum numbers. The proton–neutron model explained the puzzle of dinitrogen. When 14N was proposed to consist of 3 pairs each of protons and neutrons, with an additional unpaired neutron and proton each contributing a spin of ħ in the same direction for a total spin of 1 ħ, the model became viable.
|
|
This means that there is one unpaired electron and the total electron spin of the atom is 1/2. Moreover, the nucleus of caesium-133 has a nuclear spin equal to 7/2. The simultaneous presence of electron spin and nuclear spin leads, by a mechanism called hyperfine interaction, to a (small) splitting of all energy levels into two sub-levels. One of the sub-levels corresponds to the electron and nuclear spin being parallel (i.e.
|
|
The river at left has encountered a formation of erosion- resistant volcanic breccia, causing it to downcut more rapidly on the right, leaving terraces of different elevations. Paired and unpaired terraces: Terraces of the same elevation on opposite sides of either a stream or river are called paired terraces. They occur when it downcuts evenly on both sides and terraces on one side of the river correspond in height with those on the other side. Paired terraces are caused by river rejuvenation.
|
|
EPR spectrum of a spin label A spin label (SL) is an organic molecule which possesses an unpaired electron, usually on a nitrogen atom, and the ability to bind to another molecule. Spin labels are normally used as tools for probing proteins or biological membrane-local dynamics using electron paramagnetic resonance spectroscopy. The site-directed spin labeling (SDSL) technique allows one to monitor a specific region within a protein. In protein structure examinations, amino acid-specific SLs can be used.
|
|
Border cells in the ovary of Drosophila melanogaster are set of ~8 migratory cells that support the oocyte during oogenesis. Specifically, these cells migrate from the anterior of the egg chamber toward the posterior, where they ultimately aid in forming a pore for sperm entry. The differentiation of border cells from the static follicular epithelium is set by a morphogen gradient, from the morphogen Unpaired (Upd). Like the aforementioned neuronal Upd, ovarian Upd acts as a ligand for JAK/STAT signaling.
|
|
Polar reactions are characterized by the movement of electron pairs from a well-defined source (a nucleophilic bond or lone pair) to a well- defined sink (an electrophilic center with a low-lying antibonding orbital). Participating atoms undergo changes in charge, both in the formal sense as well as in terms of the actual electron density. The vast majority of organic reactions fall under this category. Radical reactions are characterized by species with unpaired electrons (radicals) and the movement of single electrons.
|
|
Many reactive intermediates are unstable and do not obey the octet rule. This includes species such as carbenes, borane as well as free radicals like the methyl radical (CH3) which has an unpaired electron in a non-bonding orbital on the carbon atom, and no electron of opposite spin in the same orbital. Another example is the chlorine radical produced by CFCs, known to be harmful to the ozone layer. These molecules often react so as to complete their octet.
|
|
The recognition of misfolded or mutated proteins depends on the detection of substructures within proteins such as exposed hydrophobic regions, unpaired cysteine residues and immature glycans. In mammalian cells for example, there exists a mechanism called glycan processing. In this mechanism, the lectin- type chaperones calnexin/calreticulin (CNX/CRT) provide immature glycoproteins the opportunity to reach their native conformation. They can do this by way of reglucosylating these glycoproteins by an enzyme called UDP-glucose- glycoprotein glucosyltransferase also known as UGGT.
|
|
It is not known whether all non-palindromic numbers can be paired with palindromic numbers in this way. While no number has been proven to be unpaired, many do not appear to be. For example, 196 does not yield a palindrome even after 700,000,000 iterations. Any number that never becomes palindromic in this way is known as a Lychrel number. On January 24, 2017, the number 1,999,291,987,030,606,810 was published in OEIS as A281509 and announced "The Largest Known Most Delayed Palindrome".
|
|
Anakamacops is most similar to Kamacops, sharing features such as a choana widely separated from the interpterygoid vacuities and extensive exostosis ornamenting the skull roof. Both are large taxa; the most complete specimen of Anakamacops measures 26 cm in length despite lacking most of the snout. A number of potentially unique features were suggested based on the additional material described by Liu (2018), such as a relatively edentuluous (lacking teeth) vomer and paired (rather than a single, unpaired) occipital ridge.
|
|
Paramagnetism is a weak positive response to a magnetic field due to rotation of electron spins. Paramagnetism occurs in certain kinds of iron-bearing minerals because the iron contains an unpaired electron in one of their shells (see Hund's rules). Some are paramagnetic down to absolute zero and their susceptibility is inversely proportional to the temperature (see Curie's law); others are magnetically ordered below a critical temperature and the susceptibility increases as it approaches that temperature (see Curie–Weiss law).
|
|
Behavioral neuroscience as a scientific discipline emerged from a variety of scientific and philosophical traditions in the 18th and 19th centuries. In philosophy, people like René Descartes proposed physical models to explain animal as well as human behavior. Descartes suggested that the pineal gland, a midline unpaired structure in the brain of many organisms, was the point of contact between mind and body. Descartes also elaborated on a theory in which the pneumatics of bodily fluids could explain reflexes and other motor behavior.
|
|
All atoms bigger than hydrogen are formed in stars or supernovae through nucleosynthesis, when gravity, temperature and pressure reach levels high enough to fuse protons and neutrons together. Protons and neutrons form the atomic nucleus, which accumulates electrons to form atoms. The number of protons in the nucleus, called atomic number, uniquely identifies a chemical element. The Oddo–Harkins rule argues that elements with odd atomic numbers have one unpaired proton and are more likely to capture another, thus increasing their atomic number.
|
|
In contrast to the oxide CuO, the material is not a magnetic semiconductor but a metallic conductor with weak Pauli-paramagnetism. Thus, the mineral is better described as consisting of Cu+ and S− rather than Cu2+ and S2−. Compared to pyrite with a non-closed shell of S− pairing to form S22−, there are only 2/3 of the sulfur atoms held. The other 1/3 remains unpaired and together with Cu atoms forms hexagonal layers reminiscent of the boron nitride (graphite structure).
|
|
The classification of a word as "unpaired" can be problematic, as a word thought to be unattested might reappear in real-world usage or be created, for example, through humorous back-formation. In some cases a paired word does exist, but is quite rare or archaic (no longer in general use). Such words – and particularly the back-formations, used as nonce words – find occasional use in wordplay, particularly light verse. There are a handful of notable examples in modern English.
|
|
Although a strong tendency to pair off electrons can be observed in chemistry, it is also possible that electrons occur as unpaired electrons. In the case of metallic bonding the magnetic moments also compensate to a large extent, but the bonding is more communal so that individual pairs of electrons cannot be distinguished and it is better to consider the electrons as a collective 'ocean'. A very special case of electron pair formation occurs in superconductivity: the formation of Cooper pairs.
|
|
Triplet oxygen, 3O2, refers to the S = 1 electronic ground state of molecular oxygen (dioxygen). It is the most stable and common allotrope of oxygen. Molecules of triplet oxygen contain two unpaired electrons, making triplet oxygen an unusual example of a stable and commonly encountered diradical: it is more stable as a triplet than a singlet. According to molecular orbital theory, the electron configuration of triplet oxygen has two electrons occupying two π molecular orbitals (MOs) of equal energy (that is, degenerate MOs).
|
|
Each block could incorporate two to seven such "phonetic element" characters, written in pairs within the block, with the first half of the pair on the left. If there were an odd number of characters in a block, the unpaired character would be centered below the preceding pair. Although there is some speculation, it appears there are no characters that both the small and large scripts share. Periodically, epitaphs written using small script will be written using the large script method of linearity.
|
|
In total, there were seven pairs of characters or objects, as well as an unpaired locker. Each match won a prize. Every time a player pressed a button, the locker corresponding to that button would open up. When a player found a match, they had to press a button in the center of the stage that closed all the lockers as well as deactivate the buttons to the matched lockers, as they were already matched and not needed to match again.
|
|
These proarticulatans are incompletely segmented, as the anterior zone is free of isomers, often making a "hairband" like appearance. (example cephalozoans include Yorgia, Praecambridium, Andiva, Archaeaspinus, Ivovicia, Spriggina, Marywadea and Cyanorus.) Some cephalozoans from the family Yorgiidae demonstrate pronounced asymmetry of left and right parts of the body. For instance, Yorgia’s initial right isomer is the only one which spreads far towards the left side of the body. Archaeaspinus has an unpaired anterior lobe confined by the furrow to the left side only.
|
|
The independent samples t-test is used when two separate sets of independent and identically distributed samples are obtained, one from each of the two populations being compared. For example, suppose we are evaluating the effect of a medical treatment, and we enroll 100 subjects into our study, then randomly assign 50 subjects to the treatment group and 50 subjects to the control group. In this case, we have two independent samples and would use the unpaired form of the t-test.
|
|
It is believed that a manifestation of the Kondo effect is necessary for understanding the unusual metallic delta-phase of plutonium. The Kondo effect has been observed in quantum dot systems. In such systems, a quantum dot with at least one unpaired electron behaves as a magnetic impurity, and when the dot is coupled to a metallic conduction band, the conduction electrons can scatter off the dot. This is completely analogous to the more traditional case of a magnetic impurity in a metal.
|
|
Skull and jaw anatomy Distinguishing features of the teleosts are mobile premaxilla, elongated neural arches at the end of the caudal fin and unpaired basibranchial toothplates. The premaxilla is unattached to the neurocranium (braincase); it plays a role in protruding the mouth and creating a circular opening. This lowers the pressure inside the mouth, sucking the prey inside. The lower jaw and maxilla are then pulled back to close the mouth, and the fish is able to grasp the prey.
|
|
However the 3σ is an s-p hybrid which has lower energy than the 1π orbital which is pure p, so the 3σ is filled before the 1π. The CH radical is in fact isoelectronic with the nitrogen atom which does have three unpaired electrons in accordance with Hund's rule of maximum multiplicity. However the nitrogen atom has three degenerate p orbitals, in contrast to the CH radical where hybridization of one orbital (the 3σ) leads to an energy difference.
|
|
Each face of this polyhedron shares an edge with each other face. As a result, it requires seven colours to colour all adjacent faces, providing the lower bound for the seven colour theorem. It has an axis of 180-degree symmetry; three pairs of faces are congruent leaving one unpaired hexagon that has the same rotational symmetry as the polyhedron. The 14 vertices and 21 edges of the Szilassi polyhedron form an embedding of the Heawood graph onto the surface of a torus.
|
|
In part 1a of the schematic the oligonucleotide probe, labeled on its left end (asterisk), is shown on the top line. It is fully complementary to its target DNA (here taken from the human β-hemoglobin gene), as shown on the next line. Part of the probe includes the Recognition site for the restriction enzyme Dde I (underlined). In part 1b, the restriction enzyme has cleaved the probe and its target (Dde I leaves three bases unpaired at each end).
|
|
Ariosoma Sokotranum is a bathydemersal marine eel, usually found between 395-420 meters below the waters surface. Ariosoma Sokotranum was discovered in 1991 by Emma Stanislavovna Karmovskaya she described it as a new species of conger eel (congridae). Arisoma Sokotranum can only be found in the western Indian Ocean. The Ariosoma has between 136 - 141 vertebrae has a dark edge along the unpaired fins and light coloured pectoral fins with the branchial chamber in the region of the operculum dark.
|
|
CopA-like RNA is a family of non-coding RNAs found on the R1 plasmid. In several groups of bacterial plasmids, antisense RNAs regulate copy number through inhibition of replication initiator protein synthesis. These RNAs are characterised by a long hairpin structure interrupted by several unpaired nucleotides or bulged loops. In plasmid R1, the inhibitory complex between the antisense RNA (CopA) and its target mRNA (CopT) is characterised by a four-way junction structure and a side-by-side helical alignment.
|
|
Three pairs of openings (ostia) connect sinus and interior heart space. The interior heart is crossed by asymmetrical arranged muscular bundles which are part of the heart muscle (myocard). Seven arteries which can be categorized into five artery systems (two paired, three unpaired) emanate from the heart and run to the respective organs and body regions. After having left the arteries and having washed around the tissues the "blood" (hemolymph) is channelled to the gill (branchial) sinus via crevices (lacunae) and channels (sinus).
|
|
Transition metal compounds are paramagnetic when they have one or more unpaired d electrons. In octahedral complexes with between four and seven d electrons both high spin and low spin states are possible. Tetrahedral transition metal complexes such as are high spin because the crystal field splitting is small so that the energy to be gained by virtue of the electrons being in lower energy orbitals is always less than the energy needed to pair up the spins. Some compounds are diamagnetic.
|
|
The ground state of S2 is a triplet: a diradical, with two unpaired electrons like O2 and SO. It has the S-S bond length of 189 pm, much shorter than the S-S single bonds in S8, which are 206 pm long. Its Raman spectrum consists of a band at 715 cm−1. The corresponding O-O band for O2 is found at 1556 cm−1. The S-S bond energy is 430 kJ/mol compared to 498 kJ/mol for O2.
|
|
Complexes with zero to two unpaired electrons are considered low-spin and those with four or five are considered high-spin. Iron(II) complexes are less stable than iron(III) complexes but the preference for O-donor ligands is less marked, so that for example [Fe(NH3)6]2+ is known while [Fe(NH3)6]3+ is not. They have a tendency to be oxidized to iron(III) but this can be moderated by low pH and the specific ligands used.
|
|
A simplified explanation for the effective charge of a nucleus being one less than its actual charge is that an unpaired electron in the K-shell screens it. An elaborate discussion criticizing Moseley's interpretation of screening can be found in a paper by Whitaker which is repeated in most modern texts. A list of experimentally found X-ray transitions is available at NIST. Theoretical energies can be computed to a much greater accuracy than Moseley's law using a particle physics simulation method such as Dirac-Fock.
|
|
Diamagnetism appears in all materials and is the tendency of a material to oppose an applied magnetic field, and therefore, to be repelled by a magnetic field. However, in a material with paramagnetic properties (that is, with a tendency to enhance an external magnetic field), the paramagnetic behavior dominates. Thus, despite its universal occurrence, diamagnetic behavior is observed only in a purely diamagnetic material. In a diamagnetic material, there are no unpaired electrons, so the intrinsic electron magnetic moments cannot produce any bulk effect.
|
|
Generation of junctional diversity starts as the proteins, recombination activating gene-1 and -2 (RAG1 and RAG2), along with DNA repair proteins, such as Artemis, are responsible for single-stranded cleavage of the hairpin loops and addition of a series of palindromic, 'P' nucleotides. Subsequent to this, the enzyme, terminal deoxynucleotidyl transferase (TdT), adds further random 'N' nucleotides. The newly synthesised strands anneal to one another, but mismatches are common. Exonucleases remove these unpaired nucleotides and the gaps are filled by DNA synthesis and repair machinery.
|
|
Triboracyclopropenyl-derived compounds were first identified by their mass-to-charge ratio, as transient species in the mass spectrometry of complex mixtures of cationic boron clusters. Reactive scattering studies with O2 soon followed, revealing the relatively strong bonding within light boron clusters. Subsequently, B3 was isolated in matrices of frozen noble gases and electron paramagnetic resonance spectra were recorded which confirmed its D3h geometry. Hyperfine coupling of the unpaired electron to the 11B nucleus provided an estimate of 15% s-orbital character for the a1' HOMO.
|
|
Acquisition, Extinction, and Reacquisition of a Cerebellar Cortical Memory Trace. Journal of Neuroscience 27: 2493-2502 This pause response, called a Purkinje cell CR, was also obtained when direct mossy fibre stimulation was used as the CS and direct climbing fibre stimulation as the US. Unpaired presentations of the CS and US caused extinction of the Purkinje cell CR. When paired presentations were reintroduced after extinction, Purkinje cell CRs reappeared rapidly, mirroring the "savings" phenomenon demonstrated at the behavioral level. Purkinje cell CRs were also adaptively timed.
|
|
The head was strongly armored and provided with horn- or shovel-like projections. Of the mouthparts only the crossed, sabre-like mandibles and the spoon-shaped labium are known. All legs have a strongly prolonged and free coxal segment as in the adult. Likewise, the forelegs are developed as slender subchelate raptorial legs with nearly identical segment proportions as in the adult stage, but with a shorter tibia that may have been fused with the single-segmented tarsus, which ended in an unpaired claw.
|
|
HTML markup consists of several key components, including those called tags (and their attributes), character-based data types, character references and entity references. HTML tags most commonly come in pairs like and , although some represent empty elements and so are unpaired, for example . The first tag in such a pair is the start tag, and the second is the end tag (they are also called opening tags and closing tags). Another important component is the HTML document type declaration, which triggers standards mode rendering.
|
|
Fluoromethylidyne is not a stable chemical species but a metastable radical containing one highly reactive carbon atom bound to one fluorine atom with the formula CF. The carbon atom has a lone-pair and a single unpaired (radical) electron in the ground state. Ground-state fluoromethylidyne radicals can be produced by the ultraviolet photodissociation of dibromodifluoromethane at 248 nanometer wavelength. It readily and irreversibly dimerises to difluoroacetylene, also known as difluoroethyne, perfluoroacetylene, or di- or perfluoroethylyne. Under certain conditions it can hexamerise to hexafluorobenzene.
|
|
This snail has been studied in relation to human pathology and the epidemiology of schistosomiasis. S. masoni is known to change its host’s (B. glabrata's) behavior via the upregulation/downregulation of neuropeptides such as schistosomin and NPY, and some studies have reported that FMRFamide is aminergic, and may be implicated in the secretion of molecules to respond to infection with parasites. The ganglionic central nervous system (CNS) of B. glabrata consists of paired cerebral, pedal, pleural, parietal, and buccal ganglia, and one unpaired visceral ganglion.
|
|
First, they facilitate pairing through stabilizing an intermediate complex involved in the pairing process. Second, pairing centers promote the formation of a synaptonemal complex, in which a protein polymer acts as a scaffold to hold homologous chromosomes together during recombination. In a related study, her group also uncovered a conserved meiotic checkpoint that acts during meiosis to recognize unpaired/unsynapsed chromosomes. Cells identified as having unsynapsed chromosomes undergo apoptosis, or programmed cell death, to guard against the formation of sex cells with the wrong number of chromosomes.
|
|
Nitrogen trioxide or nitrate radical is an oxide of nitrogen with formula , consisting of three oxygen atoms covalently bound to a nitrogen atom. This highly unstable blue compound has not been isolated in pure form, but can be generated and observed as a short-lived component of gas, liquid, or solid systems. Like nitrogen dioxide , it is a radical (a molecule with an unpaired valence electron), which makes it paramagnetic. It is the uncharged counterpart of the nitrate anion and an isomer of the peroxynitrite radical .
|
|
F-center in an NaCl crystal An F-center, Farbe center or color center (from the original German Farbzentrum, where Farbe means color and zentrum means center) is a type of crystallographic defect in which an anionic vacancy in a crystal lattice is occupied by one or more unpaired electrons. Electrons in such a vacancy tend to absorb light in the visible spectrum such that a material that is usually transparent becomes colored. This is used to identify many compounds, especially zinc oxide (yellow).
|
|
SymR is an antisense RNA meaning its secondary structure has characteristic stem-and-loop elements as well as unpaired regions flanking the structure. The predicted secondary structure of SymR showcases a loop containing the nucleotide sequence CCAG. This characteristic loop is shared with the lstR-1 and OhsC RNA proteins and is predicted to be a binding site for other proteins. Currently, there are no known files on the RCSB protein data bank or SWISS-MODEL repository that indicate a predicted tertiary structure of SymR.
|
|
Molecule-based magnets comprise a class of materials which differ from conventional magnets in one of several ways. Most traditional magnetic materials are comprised purely of metals (Fe, Co, Ni) or metal oxides (CrO2) in which the unpaired electrons spins that contribute to the net magnetic moment reside only on metal atoms in d- or f-type orbitals. In molecule-based magnets, the structural building blocks are molecular in nature. These building blocks are either purely organic molecules, coordination compounds or a combination of both.
|
|
The most commonly encountered allotrope of elemental oxygen is triplet dioxygen, a diradical. The unpaired electrons participate in three- electron bonding, shown here using dashed lines. The common allotrope of elemental oxygen on Earth, , is generally known as oxygen, but may be called dioxygen, diatomic oxygen, molecular oxygen, or oxygen gas to distinguish it from the element itself and from the triatomic allotrope ozone, . As a major component (about 21% by volume) of Earth's atmosphere, elemental oxygen is most commonly encountered in the diatomic form.
|
|
Her ugly form teaches the devotee to look beyond the superficial, to look inwards and seek the inner truths of life. Dhumavati is described as a giver of siddhis (supernatural powers), a rescuer from all troubles, and a granter of all desires and rewards, including ultimate knowledge and moksha (salvation). Her worship is also prescribed for those who wish to defeat their foes. Dhumavati's worship is considered ideal for unpaired members of society, such as bachelors, widows, and world renouncers as well as Tantrikas.
|
|
Some techniques often used in word play include interpreting idioms literally and creating contradictions and redundancies, as in Tom Swifties: :"Hurry up and get to the back of the ship," Tom said sternly. Linguistic fossils and set phrases are often manipulated for word play, as in Wellerisms: :"We'll have to rehearse that," said the undertaker as the coffin fell out of the car. Another use of fossils is in using antonyms of unpaired words – "I was well-coiffed and sheveled," (back-formation from "disheveled").
|
|
Upon pairing, the female assumes the same social position as her partner. Unmated females are the lowest members in the pecking order, and are the last to have access to food and shelter. Lorenz noted one case in which a male, absent during the dominance struggles and pair bondings, returned to the flock, became the dominant male, and chose one of two unpaired females for a mate. This female immediately assumed a dominant position in the social hierarchy and demonstrated this by pecking others.
|
|
Zero field splitting (ZFS) describes various interactions of the energy levels of a molecule or ion resulting from the presence of more than one unpaired electron. In quantum mechanics, an energy level is called degenerate if it corresponds to two or more different measurable states of a quantum system. In the presence of a magnetic field, the Zeeman effect is well known to split degenerate states. In quantum mechanics terminology, the degeneracy is said to be "lifted" by the presence of the magnetic field.
|
|
Great reed warbler eggs Great reed warbler nest containing a slightly larger common cuckoo egg and four warbler eggs (Apaj, Hungary). Great reed warbler females lay 3–6 eggs in an open cup-nest in reeds. Some pairs of warblers are monogamous, but others are not, and unpaired, so-called "satellite" males still father some young. Great reed warblers defend their nests using graded alarm calls, directed towards a wide range of enemies, although these alarm calls might reveal the whereabouts of the nest to brood parasites.
|
|
Once independent, juveniles leave the adults' territory and either establish their own territory or become "floaters", unpaired birds without territories. It is probably these floaters which are mainly involved in the irregular dispersals of this species. This species of nuthatch roosts in tree holes or behind loose bark when not breeding and has the unusual habit of removing its feces from the roost site in the morning. It usually roosts alone except in very cold weather, when up to 29 birds have been recorded together.
|
|
Neck-stretching courtship ritual of the male redhead Redheads flock together on lakes and other bodies of water but will migrate in pairs, which are formed in December or January through elaborate courtship rituals. Unpaired redheads will migrate together in a ‘courting party’ that can be up to 25 individuals strong and hopefully find a mate within the group. The pair bonds are established yearly through a long courtship process. Males begin this process through neck-kinking and head throwing displays while emitting a cat-like call.
|
|
The function of the song is considered more likely related to territorial defence. Around 90% of paired and territory-holding males sing, along with some unpaired males, making the morning song a convenient tool to survey the species. The song itself is melodious and has been compared to that of a bunting or a Siberian blue robin, and is a chew-i, chit-chit-pee, chot-chot-pee, ch-ee or tu-ti-ti, ti-titu- tuoo. The species makes a variety of other calls as well.
|
|
This may occur due to an equilibrium reached in the fluvial system resulting from: slowed or paused uplift, climate change, or a change in the bedrock type. Once downcutting continues the flattened valley bottom composed of bedrock (overlain with a possible thin layer of alluvium) is left above either a stream or river channel. These bedrock terraces are the strath terraces and are erosional in nature.Burbank, D.W., and R.S. Anderson, Robert, 2001, Tectonic Geomorphology, Malden, MA: Blackwell Publishing Unpaired fluvial terraces on the South Fork of the Shoshone River, Park County, Wyoming, 1923.
|
|
Bell Mobility LTE SIM card. Bell launched LTE by using the 1700 MHz (Band 4) frequency in Toronto and surrounding areas on September 14, 2011. Since then, Bell has expanded LTE into most areas of Canada where it has HSPA coverage, and launched LTE on to the 2600 MHz (Band 7) frequency for additional bandwidth in March 2012 and on to the 700 MHz spectrum (paired bands LTE Band 12 and Band 13 [including Band 17 subset] and unpaired Band 29) in 2014. Bell will use either Band 13 or Band 12 depending on provinces.
|
|
An important aspect of the valence bond theory is the condition of maximum overlap, which leads to the formation of the strongest possible bonds. This theory is used to explain the covalent bond formation in many molecules. For example, in the case of the F2 molecule, the F−F bond is formed by the overlap of pz orbitals of the two F atoms, each containing an unpaired electron. Since the nature of the overlapping orbitals are different in H2 and F2 molecules, the bond strength and bond lengths differ between H2 and F2 molecules.
|
|
The unpaired figs in the illustration led to confusion as to the identity of the species described by Miller. Thomas Nuttall described the species in the second volume of his 1846 work The North American Sylva with specific epithet aurea ('golden' in Latin). In 1768, Scottish botanist Philip Miller described Ficus maxima, citing Carl Linnaeus' Hortus Cliffortianus (1738) and Hans Sloane's Catalogus plantarum quæ in insula Jamaica (1696). Sloane's illustration of the species, published in 1725, depicted it with figs borne singly, a characteristic of the Ficus subgenus Pharmacosycea.
|
|
Hairpin II appears to be a dynamic feature of FourU's secondary structure. It undergoes a conformational shift when exposed to temperatures above 45 °C, becoming increasingly unpaired as temperature rises. Hairpin I, in contrast, remains stably base-paired in temperatures as high as 50 °C, which implies the structural shift of hairpin II from closed to open may have an important role in heat shock response. A later study used mutant analysis and calculations of enthalpy and entropy to support a cooperative zipper-type unfolding mechanism of FourU hairpin II in response to temperature increase.
|
|
For the case of spins arranged in a ring (periodic boundary conditions) the AKLT construction yields a unique ground state. But for the case of an open chain, the first and last spin 1 have only a single neighbor, leaving one of their constituent spin 1/2s unpaired. As a result, the ends of the chain behave like free spin 1/2 moments even though the system consists of spin 1s only. The spin 1/2 edge states of the AKLT chain can be observed in a few different ways.
|
|
The electron configuration of the central chromium atom is described as 3d with the six electrons filling the three lower-energy d orbitals between the ligands. The other two d orbitals are at higher energy due to the crystal field of the ligands. This picture is consistent with the experimental fact that the complex is diamagnetic, meaning that it has no unpaired electrons. However, in a more accurate description using molecular orbital theory, the d-like orbitals occupied by the six electrons are no longer identical with the d orbitals of the free atom.
|
|
The 4f orbitals penetrate the [Xe] core and are isolated, and thus they do not participate in bonding. This explains why crystal field effects are small and why they do not form π bonds. As there are seven 4f orbitals, the number of unpaired electrons can be as high as 7, which gives rise to the large magnetic moments observed for lanthanide compounds. Measuring the magnetic moment can be used to investigate the 4f electron configuration, and this is a useful tool in providing an insight into the chemical bonding.
|
|
The Delturinae are a subfamily of catfishes (order Siluriformes) of the family Loricariidae, including two genera, Delturus and Hemipsilichthys. This group is sister to all other loricariids except Lithogenes. The geographical distribution of Delturinae, exclusively on the southeastern Brazilian Shield, indicates southeastern Brazil acts as either a refugium for basal loricariid taxa or a point of origin for the Loricariidae. Both genera can be separated from all other loricariids by the presence of a postdorsal ridge made up of raised, median, unpaired plates and the presence of an adipose fin membrane.
|
|
Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) spectroscopy is a method for studying materials with unpaired electrons. The basic concepts of EPR are analogous to those of nuclear magnetic resonance (NMR), but it is electron spins that are excited instead of the spins of atomic nuclei. EPR spectroscopy is particularly useful for studying metal complexes or organic radicals. EPR was first observed in Kazan State University by Soviet physicist Yevgeny Zavoisky in 1944, and was developed independently at the same time by Brebis Bleaney at the University of Oxford.
|
|
Generally, samples for sequencing are prepared in such a way that the poly(A) tail is longer than the oligo(dT)50 on the surface of the flow cell. To avoid sequencing the unpaired A residues, a fill and lock treatment is needed. After hybridization, the temperature is lowered to 37◦C, and then dTTP and Virtual Terminator nucleotides corresponding to dATP, dCTP, and dGTP are added along with DNA polymerase. Virtual terminator nucleotides incorporate opposite the complementary base and prevent further incorporation because of the chemical structure appended to the nucleotide.
|
|
Organic and inorganic radicals can be detected in electrochemical systems and in materials exposed to UV light. In many cases, the reactions to make the radicals and the subsequent reactions of the radicals are of interest, while in other cases EPR is used to provide information on a radical's geometry and the orbital of the unpaired electron. EPR/ESR spectroscopy is also used in geology and archaeology as a dating tool. It can be applied to a wide range of materials such as carbonates, sulfates, phosphates, silica or other silicates.
|
|
Fragmentation arises from a homolysis processes. This cleavage results from the tendency of the unpaired electron from the radical site to pair up with an electron from another bond to an atom adjacent to the charge site, as illustrated below. This reaction is defined as a homolytic cleavage since only a single electron is transferred. The driving forces for such reaction is the electron donating abilities of the radical sites: N > S, O,π > Cl, Br > H. An example is the cleavage of carbon-carbon bonds next to a heteroatom.
|
|
A silicate mineral is generally an ionic compound whose anions consist predominantly of silicon and oxygen atoms. In most minerals in the Earth's crust, each silicon atom is the center of an ideal tetrahedron, whose corners are four oxygen atoms covalently bound to it. Two adjacent tetrahedra may share a vertex, meaning that the oxygen atom is a bridge connecting the two silicon atoms. An unpaired vertex represents an ionized oxygen atom, covalently bound to a single silicon atom, that contributes one unit of negative charge to the anion.
|
|
Cratostenophlebia schwickert, Lower Cretaceous, Brazil, cerci of male holotype Cratostenophlebia schwickerti, Lower Cretaceous, Brazil, ovipositor of female allotype specimen Males are distinguished by a weak anal angle of the hindwing base and in some species of Upper Jurassic Stenophlebia by a club-like dilation of the termial part of the abdomen. The male secondary genitalia are unknown, but probably were of the anisopterid type. The male terminalia of the abdomen are of the anisopterid type, thus composed of a pair of dorsal claspers (cerci) and an unpaired ventral process (epiproct). Nel et al.
|
|
Cyclic (alkyl)(amino)carbenes with a five-membered backbone (CAAC-5) - The carbene functionality is featured by two dots which represent the two unpaired electrons. In chemistry, cyclic(alkyl)(amino)carbenes (CAACs) are a family of stable singlet carbene ligands developed by Prof. Guy Bertrand and his group in 2005 at UC Riverside (now at UC San Diego). In marked contrast with the popular N-heterocyclic carbenes (NHC) which possess two "amino" substituents adjacent to the "carbene" center, CAACs possess one "amino" substituent and an sp3 carbon atom "alkyl".
|
|
The first step entails conversion to the hexafluorovanadate(III) salt using ammonium bifluoride: :V2O3 \+ 6 (NH4)HF2 → 2 (NH4)3VF6 \+ 3 H2O In the second step, the hexafluorovanadate is thermally decomposed. :(NH4)3VF6 → 3 NH3 \+ 3 HF + VF3 The thermal decomposition of ammonium salts is a relatively common method for the preparation of inorganic solids. VF3 can also be prepared by treatment of V2O3 with HF. VF3 is a crystalline solid with 6 coordinate vanadium atoms with bridging fluorine atoms. The magnetic moment indicates the presence of two unpaired electrons.
|
|
Because neutrons are electrically neutral, they penetrate more deeply into matter than electrically charged particles of comparable kinetic energy, and thus are valuable as probes of bulk properties. Neutrons interact with atomic nuclei and with magnetic fields from unpaired electrons, causing pronounced interference and energy transfer effects in neutron scattering experiments. Unlike an x-ray photon with a similar wavelength, which interacts with the electron cloud surrounding the nucleus, neutrons interact primarily with the nucleus itself, as described by Fermi's pseudopotential. Neutron scattering and absorption cross sections vary widely from isotope to isotope.
|
|
The valence electron configuration of Yb+3 (from YbCl3) is 4f135s25p6, which has crucial implications for the chemical behaviour of Yb+3. Also, the size of Yb+3 governs its catalytic behaviour and biological applications. For example, while both Ce+3 and Yb+3 have a single unpaired f electron, Ce+3 is much larger than Yb+3 because lanthanides become much smaller with increasing effective nuclear charge as a consequence of the f electrons not being as well shielded as d electrons. This behavior is known as the lanthanide contraction.
|
|
Electron spin resonance dating, or ESR dating, is a technique used to date newly formed materials which radiocarbon dating cannot, like carbonates, tooth enamel, or materials that have been previously heated like igneous rock. Electron spin resonance dating was first introduced to the science community in 1975, when Motoji Ikeya dated a speleothem in Akiyoshi Cave, Japan. ESR dating measures the amount of unpaired electrons in crystalline structures that were previously exposed to natural radiation. The age of substance can be determined by measuring the dosage of radiation since the time of its formation.
|
|
Thus, a description Cu+3S−S22− would seem appropriate with a delocalized hole in the valence band leading to metallic conductivity. Subsequent band structure calculations indicate however that the hole is more localized on the sulfur pairs than on the unpaired sulfur. This means that Cu+3S2−S2− with a mixed sulfur oxidation state -2 and -1/2 is more appropriate. Despite the extended formula of Cu+3S2−S2− from researchers in 1976 and 1993, others have come up with variations, such as Cu+4Cu2+2(S2)2S2.
|
|
In 2013, a thermostable group II intron reverse transcriptase (TGIRT), GsI-IIC-MRF, from G. stearothermophilus was found to retain activity up to 70°C and to exhibit high processivity and a low error rate. These properties make this enzyme useful for reverse transcribing long and/or highly structured RNA molecules. A method for determining RNA secondary structure, DMS-MaPseq, uses this enzyme because it converts normal RNA to DNA accurately but introduces mutations at unpaired bases that have been methylated by dimethyl sulfate, and the mutations can be identified via sequencing.
|
|
DNP can also be induced using unpaired electrons produced by radiation damage in solids. When electron spin polarization deviates from its thermal equilibrium value, polarization transfers between electrons and nuclei can occur spontaneously through electron-nuclear cross relaxation and/or spin-state mixing among electrons and nuclei. For example, the polarization transfer is spontaneous after a homolysis chemical reaction. On the other hand, when the electron spin system is in a thermal equilibrium, the polarization transfer requires continuous microwave irradiation at a frequency close to the corresponding electron paramagnetic resonance (EPR) frequency.
|
|
The cross effect requires two unpaired electrons as the source of high polarization. Without special condition, such a three spins system can only generate a solid effect type of polarization. However, when the resonance frequency of each electron is separated by the nuclear Larmor frequency, and when the two electrons are dipolar coupled, another mechanism occurs: the cross-effect. In that case, the DNP process is the result of irradiation of an allowed transition (called single quantum) as a result the strength of microwave irradiation is less demanded than that in the solid effect.
|
|
This trait is possibly associated with early tetrapod evolution, which probably also appears on other members of this family and can act as a link to anuran tympanum evolution. The narrow head and elongated snout of Stanocephalosaurus suggests that stress levels during biting are slightly higher than temnospondyls with a wider and shorter skull. Its skull also has an elongated preorbital region compared to other mastodonsaurids. The vertebrae of Stanocephalosaurus are rhachitomous, with a neural arch and a bipartite centrum that is divided into a large, unpaired wedge-shaped intercentrum and smaller paired pleurocentra.
|
|
Fe(acac)3 is an octahedral complex with six equivalent Fe-O bonds with bond distances of about 2.00 Å. The regular geometry is consistent with a high-spin Fe3+ core. As the metal orbitals are all evenly occupied the complex is not subject to Jahn-Teller distortions and thus adopts a D3 molecular symmetry. In contrast, the related metal acetylacetonate Mn(acac)3 adopts a more distorted octahedral structure. The 5 unpaired d-electrons also result in the complex being paramagnetic, with a magnetic moment of 5.90 μB.
|
|
This compound has idealized D3 symmetry. Six oxygen atoms surround the central ruthenium atom in an octahedral arrangement. The average Ru-O bond length in Ru(acac)3 is 2.00 Å. Because Ru(acac)3 is low spin, there is one unpaired d electron, causing this compound to be paramagnetic. Ru(acac)3 has a magnetic susceptibility, χM, of 3.032×10−6 cm3/mol with an effective magnetic moment, μeff, of 1.66 μB. As a solution in DMF, the compound oxidizes at 0.593 and reduces at -1.223 V vs the ferrocene/ferrocenium couple.
|
|
A matching between men and women is stable if there are no unpaired man and woman who prefer each other over their current partners. A stable matching always exists. Among the stable matchings, there is one in which each woman gets the best man that she ever gets in any stable matching; this is known as the woman-optimal stable matching. The decision version of the stable matching problem is, given the rankings of all men and women, whether a given man and a given woman are matched in the woman-optimal stable matching.
|
|
Depending upon the sequence and other conditions, nucleic acids can form a variety of structural motifs which is thought to have biological significance. ;Stem-loop: Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded DNA or, more commonly, in RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when read in opposite directions, base-pair to form a double helix that ends in an unpaired loop.
|
|
The frontonasal process, or frontonasal prominence is one of the five swellings that develop to form the face. The frontonasal process is unpaired, and the others are the paired maxillary prominences, and the paired mandibular prominences. During the fourth week of embryonic development, an area of thickened ectoderm develops, on each side of the frontonasal process called the nasal placodes or olfactory placodes, and appear immediately under the forebrain. By invagination these areas are converted into two nasal pits, which indent the frontonasal prominence and divide it into medial and lateral nasal processes.
|
|
Iron is especially common because it represents the minimum energy nuclide that can be made by fusion of helium in supernovae. The Oddo–Harkins rule holds that elements with even atomic numbers are more common that those with odd atomic numbers, with the exception of hydrogen. This rule argues that elements with odd atomic numbers have one unpaired proton and are more likely to capture another, thus increasing their atomic number. In elements with even atomic numbers, protons are paired, with each member of the pair offsetting the spin of the other, enhancing stability.
|
|
Many materials have unpaired electron spins, and the majority of these materials are paramagnetic. When the spins interact with each other in such a way that the spins align spontaneously, the materials are called ferromagnetic (what is often loosely termed as magnetic). Because of the way their regular crystalline atomic structure causes their spins to interact, some metals are ferromagnetic when found in their natural states, as ores. These include iron ore (magnetite or lodestone), cobalt and nickel, as well as the rare earth metals gadolinium and dysprosium (when at a very low temperature).
|
|
In a magnet it is the unpaired electrons, aligned so they spin in the same direction, which generate the magnetic field. This gives the Nd2Fe14B compound a high saturation magnetization (Js ≈ 1.6T or 16kG) and a remnant magnetization of typically 1.3 teslas. Therefore, as the maximum energy density is proportional to Js2, this magnetic phase has the potential for storing large amounts of magnetic energy (BHmax ≈ 512kJ/m3 or 64MG·Oe). This magnetic energy value is about 18 times greater than "ordinary" ferrite magnets by volume and 12 times by mass.
|
|
Thus, S1 is usually, but not always, the only relevant singlet excited state. This excited state S1 can further relax to S0 by IC, but also by an allowed radiative transition from S1 to S0 that emits a photon; this process is called fluorescence. Jablonski diagram. Radiative paths are represented by straight arrows and non-radiative paths by curly lines. Alternatively, it is possible for the excited state S1 to undergo spin inversion and to generate a triplet excited state T1 having two unpaired electrons with the same spin.
|
|
Nitrogen dioxide is a reddish-brown gas above with a pungent, acrid odor, becomes a yellowish-brown liquid below , and converts to the colorless dinitrogen tetroxide () below . The bond length between the nitrogen atom and the oxygen atom is 119.7 pm. This bond length is consistent with a bond order between one and two. Unlike ozone, O3, the ground electronic state of nitrogen dioxide is a doublet state, since nitrogen has one unpaired electron, which decreases the alpha effect compared with nitrite and creates a weak bonding interaction with the oxygen lone pairs.
|
|
Mechanisms that do not involve a carbocation intermediate may react through other mechanisms that have other regioselectivities not dictated by Markovnikov's rule, such as free radical addition. Such reactions are said to be anti-Markovnikov, since the halogen adds to the less substituted carbon, the opposite of a Markovnikov reaction. Similar to a positive charged species, the radical species is most stable when the unpaired electron is in the more substituted position. The anti-Markovnikov rule can be illustrated using the addition of hydrogen bromide to propene in the presence of benzoyl peroxide.
|
|
The only sounds that ostriches produce are roars and hisses. The largest air sacs found within the respiratory system are those of the post-thoracic region, while the others decrease in size respectively, the interclavicular (unpaired), abdominal, pre-thoracic, and lateral clavicular sacs. The adult common ostrich lung lacks connective tissue known as interparabronchial septa, which render strength to the non-compliant avian lung in other bird species. Due to this the lack of connective tissue surrounding the parabronchi and adjacent parabronchial lumen, they exchange blood capillaries or avascular epithelial plates.
|
|
In Northern areas it is known as the Northern Eggar; this was formerly thought to be a separate species, but is generally assumed to be a subspecies Lassiocampa quercus callunae, there is no clear geographical separation of the two types, but the Northern Eggar tends to be the larger of the two. There are morphological differences and different food preferences. Males tend to be day fliers, while females tend to fly from dusk. Unpaired females may attract a large number of males, and eggs are laid loosely in undergrowth.
|
|
The original 1858 synthesis by Liebig reacted benzoyl chloride with barium peroxide, a reaction that probably follows this equation: :2 C6H5C(O)Cl + BaO2 → (C6H5CO)2O2 \+ BaCl2 Benzoyl peroxide is usually prepared by treating hydrogen peroxide with benzoyl chloride. :2 C6H5COCl + H2O2 \+ 2 NaOH → (C6H5CO)2O2 \+ 2 NaCl + 2 H2O The oxygen–oxygen bond in peroxides is weak. Thus, benzoyl peroxide readily undergoes homolysis (symmetrical fission), forming free radicals: :(C6H5CO)2O2 → 2 The symbol • indicates that the products are radicals; i.e., they contain at least one unpaired electron.
|
|
The Berezinskii–Kosterlitz–Thouless transition (BKT transition) is a phase transition of the two-dimensional (2-D) XY model in statistical physics. It is a transition from bound vortex-antivortex pairs at low temperatures to unpaired vortices and anti-vortices at some critical temperature. The transition is named for condensed matter physicists Vadim Berezinskii, John M. Kosterlitz and David J. Thouless. BKT transitions can be found in several 2-D systems in condensed matter physics that are approximated by the XY model, including Josephson junction arrays and thin disordered superconducting granular films.
|
|
For several compounds containing both a nitrene group and a free radical group an ESR high-spin quartet has been recorded (matrix, crygenic temperatures). One of these has an amine oxide radical group incorporated, another system has a carbon radical group. :Nitrene radical (4 K means −452.2° Fahrenheit, equal to 4 Kelvin) In this system one of the nitrogen unpaired electrons is delocalized in the aromatic ring making the compound a σ–σ–π triradical. A carbene nitrogen radical (imidyl radical) resonance structure makes a contribution to the total electronic picture.
|
|
The vertebrae of the Stanocephalosaurus are rhachitomous, with a neural arch and a bipartite centrum that is divided into a large, unpaired wedge-shaped intercentrum and smaller paired pleurocentra. In anterior and posterior views, the intercentrum is a dorsally half-ring, surrounding the persistent notochord from ventral and lateral sides. Lateral and ventral surfaces of the intercentrum are smooth, suggesting a continuation of cartilage due to the unfinished medial surface. The posterodorsal margin of the intercentrum also shows a parapophysis for articulation with the capitulum of the ribs.
|
|
DNA-V complexes form in the hundreds and prevent further copies of the complement strand from being made while also "pre-packaging" and stabilize the ssDNA into an almost linear form. About 1500 copies of V form a flexible, semi-enclosed left-handed helix that encapsulate the DNA. The ssDNA does not interact with itself inside the capsule, and remains untwisted and unpaired except for the extremely stable packing signal. The PS exists as an imperfect hairpin and is responsible for the attachment and orientation of the genome in the phage.
|
|
Thomas "Herc" Hauk is a fictional character on the HBO drama The Wire, played by Domenick Lombardozzi. The series introduces Herc as a detective in the Baltimore Police Department's Narcotics Unit, begrudgingly detailed to the initial Barksdale investigation. He is generally portrayed as encapsulating the failings of the contemporary Baltimore police officer: simple-minded, concerned with petty street arrests and minor drug charges, and priding himself and his colleagues on banging heads "the Western District way." He is also partner and best friend of Ellis Carver, the two rarely being unpaired until later seasons.
|
|
Gadolinium salts are of primary interest for relaxation agents in magnetic resonance imaging (MRI). This technique exploits the fact that Gd3+ has an electronic configuration of f7. Seven is the largest number of unpaired electron spins possible for an atom, so Gd3+ is a key component in the design of highly paramagnetic complexes. To generate the relaxation agents, Gd3+ sources such as GdCl3∙6H2O are converted to coordination complexes. GdCl3∙6H2O can not be used as an MRI contrasting agent due to its low solubility in water at the body's near neutral pH.
|
|
The insect VNC develops according to a body plan based on a segmental set of 30 paired and one unpaired neuroblasts. A neuroblast can be uniquely identified based on its position in the array, its pattern of molecular expression, and the suite of early neurons that it produces. Each neuroblast gives rise to two hemilineages: an "A" hemilineage characterized by active Notch signalling, and a "B" hemilineage characterized by an absence of active Notch signalling. Research in the fruit fly D. melanogaster suggests that all neurons of a given hemilineage release the same primary neurotransmitter.
|
|
In Hindeodus, S elements are ramiform (branch-like), M elements are makellate (pick-shaped) and P elements are pectiniform (cone-shaped). The H.parvus apparatus in particular consists of six kinds of elements arranged in 13 different positions. Nine S elements (unpair S0, paired S1, S2, S3, S4), two M elements, and one pair of P elements (P1). The S0 element is unpaired and has a long sharp cusp but lacks a posterior process. S1 and S2 elements are differentiated by being laterally compressed and having a long sharp cusp with two lateral processes.
|
|
Transition metal atoms often have magnetic moments due to the net spin of electrons that remain unpaired and do not form chemical bonds. In some solids the magnetic moments on different atoms are ordered and can form a ferromagnet, an antiferromagnet or a ferrimagnet. In a ferromagnet—for instance, solid iron—the magnetic moment on each atom is aligned in the same direction (within a magnetic domain). If the domains are also aligned, the solid is a permanent magnet, which is magnetic even in the absence of an external magnetic field.
|
|
Apparently, the three genera occurred at different time intervals. While the oldest might have been Saurodon known to occur as early as the late Coniacian, the youngest is Saurocephalus which first appeared during the early Campanian and continued on to the latest Maastrichtian. Although saurodontids were geographically widely distributed and continued until the end of the Cretaceous, they remained only moderately taxonomically diversified. Among the intriguing characters of saurodontid fishes which clearly distinguish them is the toothless unpaired bony predentary that projected from the lower jaw giving the fish a very characteristic appearance.
|
|
In physics, Optically Detected Magnetic Resonance (ODMR) is a double resonance technique by which the electron spin state of a crystal defect may be optically pumped for spin initialisation and readout. Like electron paramagnetic resonance (EPR), ODMR makes use of the Zeeman effect in unpaired electrons. The negatively charged nitrogen vacancy centre (NV−) has been the target of considerable interest with regards to performing experiments using ODMR. ODMR of NV−s in diamond has applications in magnetometry and sensing, biomedical imaging, quantum information and the exploration of fundamental physics.
|
|
Many drones mate with a given queen in flight; each dies immediately after mating, since the process of insemination requires a lethally convulsive effort. Drone honey bees are haploid (single, unpaired chromosomes) in their genetic structure, and are descended only from their mother (the queen). In temperate regions, drones are generally expelled from the hive before winter, dying of cold and starvation since they cannot forage, produce honey or care for themselves. Given their larger size (1.5 times that of worker bees), inside the hive it is believed that drones may play a significant role in thermoregulation.
|
|
This is the opposite of what happens in the case of buckminsterfullerenes in which carbon sheets are given positive curvature by the inclusion of pentagons. The large-scale structure of carbon nanofoam is similar to that of an aerogel, but with 1% of the density of previously produced carbon aerogels—or only a few times the density of air at sea level. Unlike carbon aerogels, carbon nanofoam is a poor electrical conductor. The nanofoam contains numerous unpaired electrons, which Rode and colleagues propose is due to carbon atoms with only three bonds that are found at topological and bonding defects.
|
|
When two nearby atoms have unpaired electrons, whether the electron spins are parallel or antiparallel affects whether the electrons can share the same orbit as a result of the quantum mechanical effect called the exchange interaction. This in turn affects the electron location and the Coulomb (electrostatic) interaction and thus the energy difference between these states. The exchange interaction is related to the Pauli exclusion principle, which says that two electrons with the same spin cannot also be in the same spatial state (orbital). This is a consequence of the spin-statistics theorem and that electrons are fermions.
|
|
This is a picture of a distonic ion where you can see the molecule's radical site and charge are in different locations.Distonic ions are chemical species that contain two ionic charges on the same molecule separated by two or more carbon or heteroatoms. Distonic radical ions are unique due to the fact that its charges and radical sites are in different locations (on separate atoms ), unlike regular radicals where the formal charge and unpaired electron are in the same location. These molecular species are created when ionization takes place with either zwitterions or diradicals; ultimately, a neutral molecule loses an electron.
|
|
Laboratory magnetometers measure the magnetization, also known as the magnetic moment of a sample material. Unlike survey magnetometers, laboratory magnetometers require the sample to be placed inside the magnetometer, and often the temperature, magnetic field, and other parameters of the sample can be controlled. A sample's magnetization, is primarily dependent on the ordering of unpaired electrons within its atoms, with smaller contributions from nuclear magnetic moments, Larmor diamagnetism, among others. Ordering of magnetic moments are primarily classified as diamagnetic, paramagnetic, ferromagnetic, or antiferromagnetic (although the zoology of magnetic ordering also includes ferrimagnetic, helimagnetic, toroidal, spin glass, etc.).
|
|
The term dipolar bond is used in organic chemistry for compounds such as amine oxides for which the electronic structure can be described in terms of the basic amine donating two electrons to an oxygen atom. : → O The arrow → indicates that both electrons in the bond originate from the amine moiety. In a standard covalent bond each atom contributes one electron. Therefore, an alternative description is that the amine gives away one electron to the oxygen atom, which is then used, with the remaining unpaired electron on the nitrogen atom, to form a standard covalent bond.
|
|
The fourth and fifth upper labials are beneath the eye, but separated from orbit by a series of 2-4 small scales. The body is stout. The dorsal scales are smooth or weakly keeled, in 23-25, occasionally in 19 or 21 longitudinal rows at midbody. Ventral scales and subcaudals (Myanmar, northeastern India and adjacent areas of China and Thailand) 137-176 and 36-62 respectively, subcaudals mixed paired and single, occasionally all unpaired (ventrals and subcaudals for southern China, Vietnam, Laos: 127-144 and 36-54, and Malaysian Peninsula: 133-137 and 22-28 respectively [fide Smith 1943:509]).
|
|
She and Zdorab are the last unpaired couple, and she resents the idea of marrying him until she gets to know him, at which point they become among the closest pairs in the company. She was the Oversoul's second choice to don the cloak of the starmaster if Nafai refused it. After they build a community on Earth, Nafai eventually does give her the cloak, at which point she returns to the orbiting spaceship to watch over the planet like a garden. She spends much of her time in suspended animation, with the Oversoul her only company on waking.
|
|
Some molecules contain one or more unpaired electrons, creating radicals. Most radicals are comparatively reactive, but some, such as nitric oxide (NO) can be stable. A 2-D structural formula of a benzene molecule (C6H6) The "inert" or noble gas elements (helium, neon, argon, krypton, xenon and radon) are composed of lone atoms as their smallest discrete unit, but the other isolated chemical elements consist of either molecules or networks of atoms bonded to each other in some way. Identifiable molecules compose familiar substances such as water, air, and many organic compounds like alcohol, sugar, gasoline, and the various pharmaceuticals.
|
|
Although ordinary X-ray diffraction is 'blind' to the arrangement of the spins, it has become possible to use a special form of X-ray diffraction to study magnetic structure. If a wavelength is selected that is close to an absorption edge of one of elements contained in the materials the scattering becomes anomalous and this component to the scattering is (somewhat) sensitive to the non-spherical shape of the outer electrons of an atom with an unpaired spin. This means that this type of anomalous X-ray diffraction does contain information of the desired type.
|
|
Selective 2′-hydroxyl acylation analyzed by primer extension, or SHAPE, takes advantage of reagents that preferentially modify the backbone of RNA in structurally flexible regions.1-methyl-7-nitroisatoic anhydride (1M7) undergoes hydrolysis to form adducts on the backbone of unpaired RNA nucleotides. Reagents such as N-methylisatoic anhydride (NMIA) and 1-methyl-7-nitroisatoic anhydride (1M7) react with the 2'-hydroxyl group to form adducts on the 2'-hydroxyl of the RNA backbone. Compared to the chemicals used in other RNA probing techniques, these reagents have the advantage of being largely unbiased to base identity, while remaining very sensitive to conformational dynamics.
|
|
For example, decay of tritiated methane, (R = R′ = R″ = H) produces the carbenium ion in a tetrahedral conformation, with one of the orbitals having a single unpaired electron and the other three forming a trigonal pyramid. The ion then relaxes to its more favorable trigonal planar form, with release of about 30 kcal/mol of energy—that goes into vibrations and rotation of the ion. The carbocation then can interact with surrounding molecules in many reactions that cannot be achieved by other means. When formed within a rarefied gas, the carbocation and its reactions can be studied by mass spectrometry techniques.
|
|
There remains some uncertainty about whether the slender-headed morph is an advanced ontogenetic stage, as the largest individuals all exhibit this skull morphology. Schoch & Milner (2014) identified 10 features in the diagnosis of Micropholis: (1) dermal ornament with irregularly spaced pustules; (2) accessory fangs on the vomer; (3) unpaired anterior palatal fenestra (sometimes 'fontanelle'); (4) palatine and ectopterygoid reduces to struts along medial maxillary margin; (5) short basipterygoid ramus of pterygoid; (6) basal plate with prominent posterolateral horns; (7) hyobranchial skeleton well ossified; (8) short tail; (9) elongate skull table (plesiomorphy); and (10) postparietal much longer than tabular (plesiomorphy).
|
|
The A-minor motif is a ubiquitous RNA tertiary structural motif. It is formed by the insertion of an unpaired nucleoside into the minor groove of an RNA duplex. As such it is an example of a minor groove triple. Although guanosine, cytosine and uridine can also form minor groove triple interactions, minor groove interactions by adenine are very common. In the case of adenine, the N1-C2-N3 edge of the inserting base forms hydrogen bonds with one or both of the 2’-OH’s of the duplex, as well as the bases of the duplex (see figure: A-minor interactions).
|
|
Triplet carbenes have to go through an intermediate with two unpaired electrons whereas singlet carbene can react in a single concerted step. Due to these two modes of reactivity, reactions of singlet methylene are stereospecific whereas those of triplet methylene are stereoselective. This difference can be used to probe the nature of a carbene. For example, the reaction of methylene generated from photolysis of diazomethane with cis-2-butene or with trans-2-butene each give a single diastereomer of the 1,2-dimethylcyclopropane product: cis from cis and trans from trans, which proves that the methylene is a singlet.
|
|
The first player had 30 seconds to find as many pairs as they could. The unpaired locker contained a Time Bomb that was "set to go off after 20 seconds". The first player had to deactivate the Time Bomb within the first 20 seconds by simply opening the locker containing the Time Bomb. If the first player found the time bomb, the second player also received 30 seconds to find pairs; however, if the time bomb went off (signaled by its locker opening automatically and an accompanying explosion sound), the second player only received 20 seconds.
|
|
A paired samples t-test based on a "matched-pairs sample" results from an unpaired sample that is subsequently used to form a paired sample, by using additional variables that were measured along with the variable of interest. The matching is carried out by identifying pairs of values consisting of one observation from each of the two samples, where the pair is similar in terms of other measured variables. This approach is sometimes used in observational studies to reduce or eliminate the effects of confounding factors. Paired samples t-tests are often referred to as "dependent samples t-tests".
|
|
In this case, the unpaired electrons may reside in d or f orbitals on isolated metal atoms, but may also reside in highly localized s and p orbitals as well on the purely organic species. Like conventional magnets, they may be classified as hard or soft, depending on the magnitude of the coercive field. Another distinguishing feature is that molecule-based magnets are prepared via low-temperature solution-based techniques, versus high-temperature metallurgical processing or electroplating (in the case of magnetic thin films). This enables a chemical tailoring of the molecular building blocks to tune the magnetic properties.
|
|
Paramagnetic materials include aluminium, oxygen, titanium, and iron oxide (FeO). Therefore, a simple rule of thumb is used in chemistry to determine whether a particle (atom, ion, or molecule) is paramagnetic or diamagnetic: If all electrons in the particle are paired, then the substance made of this particle is diamagnetic; If it has unpaired electrons, then the substance is paramagnetic. Unlike ferromagnets, paramagnets do not retain any magnetization in the absence of an externally applied magnetic field because thermal motion randomizes the spin orientations. (Some paramagnetic materials retain spin disorder even at absolute zero, meaning they are paramagnetic in the ground state, i.e.
|
|
Constituent atoms or molecules of paramagnetic materials have permanent magnetic moments (dipoles), even in the absence of an applied field. The permanent moment generally is due to the spin of unpaired electrons in atomic or molecular electron orbitals (see Magnetic moment). In pure paramagnetism, the dipoles do not interact with one another and are randomly oriented in the absence of an external field due to thermal agitation, resulting in zero net magnetic moment. When a magnetic field is applied, the dipoles will tend to align with the applied field, resulting in a net magnetic moment in the direction of the applied field.
|
|
Muonic helium is created by substituting a muon for one of the electrons in helium-4. The muon orbits much closer to the nucleus, so muonic helium can therefore be regarded like an isotope of helium whose nucleus consists of two neutrons, two protons and a muon, with a single electron outside. Colloquially, it could be called "helium 4.1", since the mass of the muon is slightly greater than 0.1 amu. Chemically, muonic helium, possessing an unpaired valence electron, can bond with other atoms, and behaves more like a hydrogen atom than an inert helium atom.
|
|
The Eurasian tree sparrow has no true song, but its vocalisations include an excited series of tschip calls given by unpaired or courting males. Other monosyllabic chirps are used in social contacts, and the flight call is a harsh teck. A study comparing the vocalisations of the introduced Missouri population with those of birds from Germany showed that the US birds had fewer shared syllable types (memes) and more structure within the population than the European sparrows. This may have resulted from the small size of the founding North American population and a consequent loss of genetic diversity.
|
|
5-Dehydro-m-xylylene (DMX) is an aromatic organic triradical and the first known organic molecule to violate Hund's Rule. Its electronic ground state is an open-shell doublet rather than a quartet; that is, the unpaired electrons in the three singly occupied molecular orbitals form low-spin state in which one electron has its spin-state opposed to the other two. The net result is that there is only one unopposed spin. Hund's rule would predict that the ground state would have all three radical electrons with the same spin-state as each other (none opposed), for a greater total spin.
|
|
In organic chemistry, a carbyne is a general term for any compound whose structure consists of an electrically neutral carbon atom connected by a single covalent bond and has three non-bonded electrons. The carbon atom has either one or three unpaired electrons, depending on its excitation state; making it a radical. The chemical formula can be written R-C• or R-C3• (also written as ⫶C-R), or just CH. Carbynes can be seen as derivatives of the simplest such compound, the methylidyne radical or unsubstituted carbyne HC• or HC3•, in which the functional group is a hydrogen atom.
|
|
A hemocyanin active site in the absence of O2 (each Cu center is a cation, charges not shown). O2-bound form of a hemocyanin active site (the Cu2 center is a dication, charge not shown). Spectroscopy of oxyhemocyanin shows several salient features: # Resonance Raman spectroscopy shows that O2 is bound in a symmetric environment (ν(O-O) is not IR-allowed). # OxyHc is EPR-silent indicating the absence of unpaired electrons # Infrared spectroscopy shows ν(O-O) of 755 cm−1 Much work has been devoted to preparing synthetic analogues of the active site of hemocyanin.
|
|
Copper(II) acetate dihydrate Ferrimagnetic ordering in 2 dimensions Antiferromagnetic ordering in 2 dimensions Exchange interactions occur when the substance is not magnetically dilute and there are interactions between individual magnetic centres. One of the simplest systems to exhibit the result of exchange interactions is crystalline copper(II) acetate, Cu2(OAc)4(H2O)2. As the formula indicates, it contains two copper(II) ions. The Cu2+ ions are held together by four acetate ligands, each of which binds to both copper ions. Each Cu2+ ion has a d9 electronic configuration, and so should have one unpaired electron.
|
|
Electron paramagnetic resonance (EPR) or electron spin resonance (ESR) is a spectroscopic technique widely used in biology, chemistry, medicine and physics to study systems with one or more unpaired electrons. Because of the specific relation between the magnetic parameters, electronic wavefunction and the configuration of the surrounding non-zero spin nuclei, EPR and ENDOR provide information on the structure, dynamics and the spatial distribution of the paramagnetic species. However, these techniques are limited in spectral and time resolution when used with traditional continuous wave methods. This resolution can be improved in pulsed EPR by investigating interactions separately from each other via pulse sequences.
|
|
The primary function of MSH3 is to maintain the stability of the genome and enact tumor suppression by forming the heterodimer MutSβ to correct long insertion/deletion loops and base-base mispairs. In the case of long insertion/deletion loops, DNA is severely bent and downstream basepairs can become unpaired and exposed. MutSβ recognizes insertion/deletion loops of 1-15 nucleotides; binding to insertion/deletion loops is achieved by inserting the mismatch-binding domain of MSH3 and part of the mismatch-binding domain of MSH2 into the groove formed by the extreme bend in DNA formed by the insertion/deletion loop.
|
|
While both proteins have redundant function in base-base repairs, MutSα typically effects base-base mispair repairs and also performs repairs on the more common short inertion/deletion loops. When MSH3 is heavily overexpressed, it acts as a sequester for MSH2 and the relative levels of MutSβ and MutSα shift dramatically as unpaired MSH6 proteins degrade and MutSα becomes depleted. MutSβ can compensate somewhat for loss of base-base mispair correction functions, but is not suited for repairing many short, 1-2 base pair insertion/deletion loops. This leads to a heightened rate of microsatellite instabilities and increased rates of somatic mutations.
|
|
Any nucleus with more than one unpaired nuclear particle (protons or neutrons) will have a charge distribution which results in an electric quadrupole moment. Allowed nuclear energy levels are shifted unequally due to the interaction of the nuclear charge with an electric field gradient supplied by the non-uniform distribution of electron density (e.g. from bonding electrons) and/or surrounding ions. As in the case of NMR, irradiation of the nucleus with a burst of RF electromagnetic radiation may result in absorption of some energy by the nucleus which can be viewed as a perturbation of the quadrupole energy level.
|
|
Many of methylene's electronic states lie relatively close to each other, giving rise to varying degrees of radical chemistry. The ground state is a triplet radical with two unpaired electrons (X̃3B1), Isaiah Shavitt (1985), Geometry and singlet-triplet energy gap in methylene: A critical review of experimental and theoretical determinations. Tetrahedron, volume 41, issue 8, page 1531 and the first excited state is a singlet non-radical (ã1A1). With the singlet non-radical only 38 kJ above the ground state, a sample of methylene exists as a mixture of electronic states even at room temperature, giving rise to complex reactions.
|
|
The howler monkey Alouatta has a pneumatized hyoid bone, one of the few cases of postcranial pneumatization of bones outside Saurischia. In veterinary anatomy, the term hyoid apparatus is the collective term used to refer to the bones of the tongue — a pair of stylohyoidea, a pair of thyrohyoidea, and unpaired basihyoideumShoshani J., Marchant G.H. (2001.) Hyoid apparatus: a little-known complex of bones and its "contribution" to proboscidean evolution, The World of Elephants - International Congress, Rome, pp. 668–675. — and associated, upper-gular connective tissues. In humans, the single hyoid bone is an equivalent of the hyoid apparatus.
|
|
One variant of the best possible hand in Razz Razz is similar to seven-card stud, except the lowest hand wins. Seven cards are dealt to each player, but only the five best cards (generally the five lowest unpaired cards) are used in forming a complete hand.Pokerstars.com: Razz (7 Card Stud Low) Razz is usually played with a maximum of eight players, with limit betting, meaning that there is a fixed amount that can be bet per player per round. Each player antes and is dealt two cards face down (the hole cards), and one card face up (the "door card").
|
|
The Spy&Go; affinity resin is based on SpyCatcher2.1 E77A S49C variant termed SpyDock. SpyDock can be expressed in E. coli as soluble protein, purified using Ni-NTA and anion-exchange resins and immobilized to iodoacetyl-activated agarose through the unpaired cysteine introduced by the S49C substitution. In neutral buffers with physiological salt concentration SpyDock binds to SpyTag- and SpyTag002-fused proteins with affinity in the high nanomolar range (Kd = 750 ± 50 nM for SpyTag, Kd = 73 ± 13 nM for SpyTag002). Affinity to SpyTag003 has not been reported, but requires harsher conditions to ensure full dissociation suggesting it binds tighter.
|
|
Moreover, even when the electron configuration is such that there are unpaired electrons and/or non-filled subshells, it is often the case that the various electrons in the solid will contribute magnetic moments that point in different, random directions so that the material will not be magnetic. Sometimes, either spontaneously, or owing to an applied external magnetic field—each of the electron magnetic moments will be, on average, lined up. A suitable material can then produce a strong net magnetic field. The magnetic behavior of a material depends on its structure, particularly its electron configuration, for the reasons mentioned above, and also on the temperature.
|
|
Tip of permanent magnet with coins demonstrating ferromagnetism A ferromagnet, like a paramagnetic substance, has unpaired electrons. However, in addition to the electrons' intrinsic magnetic moment's tendency to be parallel to an applied field, there is also in these materials a tendency for these magnetic moments to orient parallel to each other to maintain a lowered-energy state. Thus, even in the absence of an applied field, the magnetic moments of the electrons in the material spontaneously line up parallel to one another. Every ferromagnetic substance has its own individual temperature, called the Curie temperature, or Curie point, above which it loses its ferromagnetic properties.
|
|
Lack of the acentric fragment in one of the daughter cells may have deleterious consequences, depending on the function of the DNA in this region of the chromosome. In the case of a haploid organism or a gamete, it will be fatal to one of the daughter cells if essential DNA is contained in the lost DNA segment. In the case of a diploid organism, the daughter cell lacking the acentric fragment will show expression of any recessive genes found in the homologous chromosome. Developmental geneticists look for cells and cell lineages lacking unpaired chromosome segments produced this way as a means of identifying essential genes for specific functions.
|
|
A photocarcinogen is a substance which causes cancer when an organism is exposed to it, then illuminated. Many chemicals that are not carcinogenic can be photocarcinogenic when combined with exposure to light, especially UV. This can easily be understood from a photochemical perspective: The reactivity of a chemical substance itself might be low, but after illumination it transitions to an excited state, which is chemically much more reactive and therefore potentially harmful to biological tissue and DNA. Light can also split photocarcinogens, releasing free radicals, whose unpaired electrons cause them to be extremely reactive. Determination of photocarcinogenicity can be accomplished using different techniques, including epidemiological studies and in-vivo studies.
|
|
When these enzymes try to mend the mutational damage, they unwind DNA into single strands and create lesion regions that do not have a purine/pyrimidine base. Across the lesion region, the bases in the unpaired, single-stranded DNA(ssDNA) are more accessible to the modifying enzyme groups that can cause further damage in the sequence, thus forming the mutational clusters seen in kataegis. Two enzyme families are assumed to be related to kataegis. The APOBEC("apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like") enzyme family causes predominately C→T mutations, and translesional DNA synthesis (TLS) DNA polymerase causes C→G or C→T mutations.
|
|
Coliphage HK022, alone among the known lambdoid phages, does not encode an analog to lambda N. Instead, it promotes antitermination of early phage transcription through the direct action of transcribed sequences called put (for polymerase utilization) sites. There are two closely related put sites, one located in the PL operon and the other located in the PR operon, roughly corresponding to the positions of the nut sequences in lambda and in other lambda relatives. put sites act in cis to promote readthrough of downstream terminators in the absence of all HK022 proteins. The put transcripts are predicted to form two stem-loops separated by a single unpaired nucleotide.
|
|
RsaOG (an acronym for RNA S. aureus Orsay G) is a non-coding RNA that was discovered in the pathogenic bacteria Staphylococcus aureus N315 using a large scale computational screening based on phylogenetic profiling. It was first identified, but not named, in 2005. RsaOG has since been identified in other strains of Staphylococcus aureus under the name of RsaI, it has also been discovered in other members of the Staphylococcus genus (such as Staphylococcus carnosus) but in no other bacteria. The RsaOG gene is conserved in all Staphylococcaceae sequenced genomes, its secondary structure contains two highly conserved unpaired sequences which have the ability to form a pseudoknot.
|
|
Therefore, if two atoms of the lattice are separate by a distance greater than the Hill limit, the overlap of their f-orbital becomes negligible. A direct consequence is the absence of hopping for the f electrons, ie their localization on the ion sites of the lattice. Localized f electrons lead to paramagnetic materials since the remaining unpaired spins are stuck in their orbitals. However, when the rare- earth lattice (or a single atom) is embedded in a metallic one (intermetallic compound), interactions with the conduction band allow the f electrons to move through the lattice even for interatomic distances above the Hill limit.
|
|
The female Eurasian treecreeper forages primarily on the upper parts of the tree trunks, while the male uses the lower parts. A study in Finland found that if a male disappears, the unpaired female will forage at lower heights, spend less time on each tree and have shorter foraging bouts than a paired female. This bird may sometimes join mixed- species feeding flocks in winter, but it does not appear to share the resources found by accompanying tits and goldcrests, and may just be benefiting from the extra vigilance of a flock. Wood ants share the same habitat as the treecreeper, and also feed on invertebrates on tree trunks.
|
|
Such approximation takes into account the through-space magnetic interactions of the two magnetic dipoles. Isolation of R gives the distance from the origin (localized unpaired electron) to the spin active nucleus. Point-dipole approximations are calculated using the following equation on the right: ENDOR technique has been used to characterize of spatial and electronic structure of metal-containing sites. paramagnetic metal ions/complexes introduced for catalysis; metal clusters producing magnetic materials; trapped radicals introduced as probes for disclosing the surface acid/base properties; color centers and defects as in ultramarine blue and other gems; and catalytically formed trapped reaction intermediates that detail the mechanism.
|
|
This means a crystal of the material preferentially magnetizes along a specific crystal axis but is very difficult to magnetize in other directions. Like other magnets, the neodymium magnet alloy is composed of microcrystalline grains which are aligned in a powerful magnetic field during manufacture so their magnetic axes all point in the same direction. The resistance of the crystal lattice to turning its direction of magnetization gives the compound a very high coercivity, or resistance to being demagnetized. The neodymium atom can have a large magnetic dipole moment because it has 4 unpaired electrons in its electron structure as opposed to (on average) 3 in iron.
|
|
Molecules that could be antiaromatic will tend to change from this electronic or conformation, thereby becoming non-aromatic. For example, cyclooctatetraene (COT) distorts out of planarity, breaking π overlap between adjacent double bonds. Recent studies have determined that cyclobutadiene adopts an asymmetric, rectangular configuration in which single and double bonds indeed alternate, with no resonance; the single bonds are markedly longer than the double bonds, reducing unfavorable p-orbital overlap. This reduction of symmetry lifts the degeneracy of the two formerly non-bonding molecular orbitals, which by Hund's rule forces the two unpaired electrons into a new, weakly bonding orbital (and also creates a weakly antibonding orbital).
|
|
Only when it is in a positive oxidation state, that is, in combination with oxygen or fluorine, are its compounds good oxidising agents, for example, 2NO3− → N2 = 1.25 V. Its chemistry is largely covalent in nature; anion formation is energetically unfavourable owing to strong inter electron repulsions associated with having three unpaired electrons in its outer valence shell, hence its negative electron affinity. The common oxide of nitrogen (NO) is weakly acidic. Many compounds of nitrogen are less stable than diatomic nitrogen, so nitrogen atoms in compounds seek to recombine if possible and release energy and nitrogen gas in the process, which can be leveraged for explosive purposes.
|
|
By comparing this isotropic hyperfine coupling constant to the theoretical hyperfine splitting of an electron in a pure valence s orbital, one can calculate the percent of the unpaired spin density in the valence s orbital. Similarly, the ratio of the anisotropic hyperfine coupling constant to the anisotropic hyperfine coupling of a single electron in a pure atomic p orbital reveals the percent of spin occupation in a valence p orbital. However, measurement of the anisotropic component of the hyperfine tensor are more difficult and not as frequent in literature. The percent of spin occupation in the valence s orbital can be used to directly probe the structure of these molecules.
|
|
Cobalt, 9.Magnetite Below its Curie point of 770 °C, α-iron changes from paramagnetic to ferromagnetic: the spins of the two unpaired electrons in each atom generally align with the spins of its neighbors, creating an overall magnetic field. This happens because the orbitals of those two electrons (dz2 and dx2 − y2) do not point toward neighboring atoms in the lattice, and therefore are not involved in metallic bonding. In the absence of an external source of magnetic field, the atoms get spontaneously partitioned into magnetic domains, about 10 micrometers across, such that the atoms in each domain have parallel spins, but some domains have other orientations.
|
|
The former applies largely to the case of isotropic interactions (independent of sample orientation in a magnetic field) and the latter to the case of anisotropic interactions (spectra dependent on sample orientation in a magnetic field). Spin polarization is a third mechanism for interactions between an unpaired electron and a nuclear spin, being especially important for \pi-electron organic radicals, such as the benzene radical anion. The symbols "a" or "A" are used for isotropic hyperfine coupling constants, while "B" is usually employed for anisotropic hyperfine coupling constants.Strictly speaking, "a" refers to the hyperfine splitting constant, a line spacing measured in magnetic field units, while A and B refer to hyperfine coupling constants measured in frequency units.
|
|
A cribbage only counts when the paired balls are pocketed in succession in the same . Where a player pockets a first paired ball and is thus on a cribbage, if the companion ball is not pocketed on the next stroke, the shot is a foul and the unpaired balls of any cribbages not completed are to the . If the foot spot is occupied, balls are spotted as close as possible to the foot spot on the stretching back from the foot spot to the . The penalty for all fouls is the ending of the player's inning; no points are lost, and the incoming player has the option of shooting from position or taking from the (behind the table's ).
|
|
Intersystem crossing and associated spin- state orbitals of Fluorenylidene. The ground state is believed to be a bent triplet, with two orthogonal sp hybrid orbitals singly occupied by unpaired spins. One electron occupies an orbital of sigma symmetry in the plane of the rings, while the other occupies an orbital of pi symmetry, which interacts with the pi systems of the adjacent aromatic rings (delocalization into the rings is minimal, since zero-field parameter D is high). The zero field splitting parameters predict a bond angle greater than 135°, and since the ideal bond geometry for cyclopentane carbons is about 109°, considerable ring strain causes the methylene sigma bonds to be bent.
|
|
The unpaired figs in the illustration led to confusion as to the identity of the species described by Miller.In 1768, Scottish botanist Philip Miller described Ficus maxima, citing Linnaeus' Hortus Cliffortianus (1738) and Hans Sloane's Catalogus plantarum quæ in insula Jamaica (1696). Sloane's illustration of this plant (published in his 1725 A voyage to the islands Madera, Barbados, Nieves, S. Christophers and Jamaica) depicted it with figs borne singly, a characteristic of the Ficus subgenus Pharmacosycea. A closer examination of Sloane's description led Cornelis Berg to conclude that the illustration depicted a member of the subgenus Urostigma, almost certainly F. aurea, and that the illustration of singly borne figs was probably artistic license.
|
|
McConnell did important research to the understanding of the relation between molecular electronic structure and electron and nuclear magnetic resonance spectra during the period of 1955 through 1965. After that, he developed the technique of spin-labels, whereby electron and nuclear magnetic resonance spectra can be used to study the structure and kinetics of proteins and membranes. He recognized that the discovery of nuclear hyperfine interactions in aromatic free radicals represented a major breakthrough in the study of the electronic structure of unsaturated hydrocarbons. His theoretical and experimental studies of nuclear hyperfine interactions in such compounds showed conclusively that this interaction gave a measure of the unpaired electron spin densities on the carbon atoms (see McConnell equation for details).
|
|
Papaver somniferum × Papaver bracteatum, also known as Sagan's poppy is a hybrid between the opium poppy and the Iranian poppy. This hybrid, true poppy is diploid with 18 chromosomes and exhibits strongly reduced fitness relative to parents, possibly due to unpaired chromosomes since the Iranian and opium poppies do not have the same number. The clearest example of its reduced fitness is seen through semilethal dwarfism, with about 53.4% of specimens grown exhibiting dwarfism. While this hybrid does not possess the cold hardiness of the Iranian poppy (Papaver bracteatum), it does possess notably more cold tolerance than Papaver somniferum and in a greenhouse or protected setting could be grown as a perennial.
|
|
The reaction can proceed in the absence of an electron acceptor, but it will have a much lower efficiency, producing byproducts resulting from the excited Ru(Bpy)3 reacting with oxygen. As an effective single electron oxidizer, Ru3+ will pick up a single electron from amino acids of the neighboring proteins, most commonly Tryptophan and Tyrosine. This produces a radical that is highly unstable on the amino acid side chains, which proceeds through reactions to reach a more stable state. Formation of covalent bond between amino acid side chains (Tyrosine)The unpaired single electron on the side chain reacts with another amino acid side chain of a polypeptide in the vicinity, resulting in a dimer with a covalent bond.
|
|
In nematodes, the ring consists of only two to four large associative cells connected to two paired lateral ganglia, two ventral ganglia, and a single unpaired dorsal ganglion. Among arthropods, the usual arrangement is a single ganglion (the cerebral) positioned above the esophagus, a single ganglion or nerve mass (the subesophageal) below it, and commissures connecting the two in a ring. Among the gastropods, the evolutionary torsion event which relocates the anus to near the head of the animal and allowing it to withdraw into its shell has relocated the commissure of the pleural ganglia into a "twist" (the right ganglion has relocated to the left side, and the left ganglion to the right).
|
|
This theory proposes that the single unpaired penis is the ancestral state for amniotes, and that this trait was retained by most amniotes today. A look at the embryonic underpinning of hemipenes and penises of other animals suggests that there are fundamental differences in their developmental stages, particularly their origin of development relative to the embryonic cloaca. Specifically, the hemipenes of squamata are found to develop on the posterior side, while the paired genitals of non-squamata amniota develop on the anterior side. This developmentally significant difference suggests that the two types of penises could have distinct homologies, and it is thought that this could be attributed to variance of signaling genes during embryological development.
|
|
When ripe females are receptive, males will court them, after a chase sequence through aquatic foliage in which several males may pursue an individual female, breaking off to pursue a different female as the opportunity arises, resulting in the aquarium in mad dashes hither and thither. Eventually, close observation will see a male court a female in some secluded area of aquatic foliage. The courting gesture of the male consists of a quivering motion, with a head-down posture, and the 'flicking' of the unpaired fins in such a manner as to generate flashes of yellow colouration in the visual field of the female. These flashes will be readily visible to the observing aquarist.
|
|
J. Chem. 49(22),(1971), 3733 The unpaired electron in the radical can be detected with electron paramagnetic resonance and barium dithionate has been proposed as the basis for a radiation dosimeter.Barium dithionate as an EPR dosemeter Baran M.P., Bugay O.A., Kolesnik S. P., Maksimenko V. M., Teslenko V. V., Petrenko T. L. Desrosiers M. F. Radiation Protection Dosimetry 2006 120, 202; The dithionate ion can act as a bidentate ligand.Structures of Some Copper (II) Complexes Containing Ion Ishii M. Bulletin of the Yamagata University 5, 1,(2001), 7 The structure of the dithionate ion in the solid state is staggered in Na2S2O6·2H2O, whereas in the anhydrous potassium salt it is nearly eclipsed.
|
|
Free radicals, molecules with unpaired electrons, play a large role in most reactions of alkanes, such as cracking and reformation where long-chain alkanes are converted into shorter-chain alkanes and straight-chain alkanes into branched-chain isomers. Moreover, redox reactions of alkanes involving free radical intermediates, in particular with oxygen and the halogens, are possible as the carbon atoms are in a strongly reduced state; in the case of methane, carbon is in its lowest possible oxidation state (−4). Reaction with oxygen (if present in sufficient quantity to satisfy the reaction stoichiometry) leads to combustion without any smoke, producing carbon dioxide and water. Free radical halogenation reactions occur with halogens, leading to the production of haloalkanes.
|
|
The orbitals of neighboring atoms overlap and a lower energy state is achieved when the spins of unpaired electrons are aligned with each other, a spontaneous process known as an exchange interaction. When the magnetic moments of ferromagnetic atoms are lined up, the material can produce a measurable macroscopic field. Paramagnetic materials have atoms with magnetic moments that line up in random directions when no magnetic field is present, but the magnetic moments of the individual atoms line up in the presence of a field. The nucleus of an atom will have no spin when it has even numbers of both neutrons and protons, but for other cases of odd numbers, the nucleus may have a spin.
|
|
The male Mongolian gazelle and musk ox possess an air space (paired and two-chambered in the former) attached to the larynx, while bears have such spaces connected to the pharynx. Male howler monkeys have an unpaired rostroventral laryngeal air sac within the hyoid bulla (extension of the hyoid bone) and a pair of ventral laryngeal air spaces outside. The hammer-headed bat has a pouch in the palatine that connects to an enlarged nasopharynx region, in addition to paired cheek pouches which extend to the rostrum. Elephants possess a pharyngeal pouch associated with their larynx and hyoid apparatus, and their roars can also be modified by the nostrils in their trunks.
|
|
Vitamin C (ascorbic acid) is a water- soluble antioxidant and a free radical scavenger where it will donate an electron to compounds with unpaired elections or reactive but not radical compounds. Supplements of Vitamin C reduce oxidative DNA damage in cats prone to kidney injury, and can be beneficial to add into diets for cats suffering from renal diseases. Vitamin C is not essential for cats as it is not required by the Association of American Feed Control Officials (AAFCO); however, it is commonly added into pet foods as an antioxidant. Ascorbic acid is known to function in gene expression as a co-substrate, and have unique biosynthetic pathways in different organisms.
|
|
A stuffed Blakiston's fish owl at the National Museum of Nature and Science in Tokyo. Blakiston's fish owl is classified as an Endangered Species by the IUCN. It is endangered due to the widespread loss of riverine forest, increasing land development along rivers and dam construction. The current population in Japan has been estimated at approximately 100-150 birds (20 breeding pairs and unpaired individuals), whereas on mainland Asia the population is higher, at times variously estimated at several hundred or perhaps up to thousands of individuals. Globally and included more recent detailed analysis from Russia, it is estimated that the population consists in total consists of about 1,000-1,500 individuals, or about 500-850 pairs.
|
|
Blunt ends are much less likely to be ligated by a DNA ligase because the blunt end doesn't have the overhanging base pair that the enzyme can recognize and match with a complementary pair. Sticky ends of DNA however are more likely to successfully bind with the help of a DNA ligase because of the exposed and unpaired nucleotides. For example, a sticky end trailing with AATTG is more likely to bind with a ligase than a blunt end where both the 5' and 3' DNA strands are paired. In the case of the example the AATTG would have a complementary pair of TTAAC which would reduce the functionality of the DNA ligase enzyme.
|
|
A parent feeding a chick in a nest in a tree hole in England Unpaired males find a suitable cavity and begin to build nests in order to attract single females, often decorating the nest with ornaments such as flowers and fresh green material, which the female later disassembles upon accepting him as a mate. The amount of green material is not important, as long as some is present, but the presence of herbs in the decorative material appears to be significant in attracting a mate. The scent of plants such as yarrow acts as an olfactory attractant to females. The males sing throughout much of the construction and even more so when a female approaches his nest.
|
|
In combination with the strong occiput of the skull, this interlocking resulted in a stiffening of the front section of the vertebral column. Such stiffening can be observed in other thunnosaurian ichthyosaurs, though not to the degree seen in Acamptonectes. The neural arches of the vertebrae feature narrow pre- and postzygapophyses (articular processes) that are unpaired (fused into a single element) in the whole vertebral column; this is in contrast to Platypterygius hercynicus and Sveltonectes, where these processes are paired in the front part of the column. The neural spines (upwards projections) are of variable height; in some dorsals they are markedly longer, reaching 1.25 times the height of the largest centrum.
|
|
For instance, as a result of the PJTE a centrosymmetric linear system may become non-centrosymmetric in the equilibrium configurations, as, for example, in the BNB molecule (see in ). An interesting extension of such distortions in sufficiently long (infinite) linear chains was first considered by Peierls.R. E. Peierls "Quantum theory of solids", Oxford, Clarendon, 1955. In this case the electronic states, combinations of atomic states, are in fact band states, and it was shown that if the chain is composed by atoms with unpaired electrons, the valence band is only half filled, and the PJTE interaction between the occupied and unoccupied band states leads to the doubling of the period of the linear chain (see also in the books ).
|
|
This complex binds and cleaves complementary base pairing messenger RNA, destroying it and preventing its translation into protein. Crystallised piwi domains have a conserved basic binding site for the 5' end of bound RNA; in the case of argonaute proteins binding siRNA strands, the last unpaired nucleotide base of the siRNA is also stabilised by base stacking-interactions between the base and neighbouring tyrosine residues. Recent evidence suggests that the functional role of piwi proteins in germ-line determination is due to their capacity to interact with miRNAs. Components of the miRNA pathway appear to be present in pole plasm and to play a key role in early development and morphogenesis of Drosophila melanogaster embryos, in which germ-line maintenance has been extensively studied.
|
|
Using ultraviolet–visible spectroscopy to study its reactions with phenol groups, after treating the samples with alkali, although the absorption curve initially showed no changes, it was observed to have shifted to higher absorption readings if one or more of the hydroxy groups were unpaired. Basing further research on this observation, Pedersen then dipped the unknown product in methanoland sodium hydroxide. Although the solution was not soluble in methanol, it became alkaline when in contact with the sodium hydroxide. thumb Due to not being soluble in methanol, Pedersen then proceeded to treat the methanol with soluble sodium salts, to which the unknown substance became soluble, allowing him to conclude that the solubility was due to sodium ions instead of alkalinity.
|
|
Therefore, under certain conditions, when the orbitals of the unpaired outer valence electrons from adjacent atoms overlap, the distributions of their electric charge in space are farther apart when the electrons have parallel spins than when they have opposite spins. This reduces the electrostatic energy of the electrons when their spins are parallel compared to their energy when the spins are anti-parallel, so the parallel-spin state is more stable. In simple terms, the electrons, which are attracted to the nuclei, can change their spatial state so that they both are closer to both nuclei by aligning their spins in opposite directions, so the spins of these electrons tend to be antiparallel. This difference in energy is called the exchange energy.
|
|
Transposable elements (transposons, TEs, 'jumping genes') are short strands of repetitive DNA that can self-replicate and translocate within the eukaryotic genome, and are generally perceived as parasitic in nature. Their transcription can lead to the production of dsRNAs (double-stranded RNAs), which resemble retroviruses transcripts. While most host cellular RNA has a singular, unpaired sense strand, dsRNA possesses sense and anti-sense transcripts paired together, and this difference in structure allows an host organism to detect dsRNA production, and thereby the presence of transposons. Plants lack distinct divisions between somatic cells and reproductive cells, and also have, generally, larger genomes than animals, making them an intriguing case-study kingdom to be used in attempting to better understand the epigenetics function of transposable elements.
|
|
Crystal structure of rubies Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only moissanite and diamond are harder, with diamond having a Mohs hardness of 10.0 and moissanite falling somewhere in between corundum (ruby) and diamond in hardness. Sapphire, ruby, and pure corundum are α-alumina, the most stable form of Al2O3, in which 3 electrons leave each aluminium ion to join the regular octahedral group of six nearby O2− ions; in pure corundum this leaves all of the aluminium ions with a very stable configuration of no unpaired electrons or unfilled energy levels, and the crystal is perfectly colorless. Crystal structure of ruby showing the substitution of Al3+ ions (blue) with Cr3+ (red).
|
|
The vomeronasal organ (VNO), or Jacobson's organ, is the paired auxiliary olfactory (smell) sense organ located in the soft tissue of the nasal septum, in the nasal cavity just above the roof of the mouth (the hard palate). The name is derived from the fact that it lies adjacent to the unpaired vomer bone (from Latin 'plowshare', for its shape) in the nasal septum. It is present and functional in all snakes and lizards, and in many mammals, including cats, dogs, horses, cattle, pigs, and some primates; in humans it is present, but is vestigial and non-functional. The VNO contains the cell bodies of sensory neurons which have receptors that detect specific non-volatile (liquid) organic compounds which are conveyed to them from the environment.
|
|
The two pathways for homologous recombination in eukaryotes, showing the formation and resolution of Holliday junctions The Holliday junction is a key intermediate in homologous recombination, a biological process that increases genetic diversity by shifting genes between two chromosomes, as well as site-specific recombination events involving integrases. They are additionally involved in repair of double-strand breaks. In addition, cruciform structures involving Holliday junctions can arise to relieve helical strain in symmetrical sequences in DNA supercoils. While four- arm junctions also appear in functional RNA molecules, such as U1 spliceosomal RNA and the hairpin ribozyme of the tobacco ringspot virus, these usually contain unpaired nucleotides in between the paired double-helical domains, and thus do not strictly adopt the Holliday structure.
|
|
While the native Swahili spoken at the time utilised 5 noun class pairs and 3 unpaired classes, KiKAR had a reduced set of only four pairs of classes. These noun classes were M-/WA-, M-/MI-, KI-/VI-, and N-/N- where the first three of these were taken from Swahili and the final pair (N-/N-) was a so called "miscellaneous" class. According to Mutonya and Parsons, H. W. Newell said in his guide “to classify all nouns not in one of the other classes as being of this [N-]class”. The simplified system of noun classes also lessened the complexity of much of the grammar which arises from the larger set of noun classes, for example nasal assimilation rules and more complex plurals.
|
|
However, quantum-mechanical calculations with accurate wave functions since the 1970s have shown that the actual physical reason for the increased stability is a decrease in the screening of electron-nuclear attractions, so that the unpaired electrons can approach the nucleus more closely and the electron-nuclear attraction is increased. As a result of Hund's rule, constraints are placed on the way atomic orbitals are filled in the ground state using the Aufbau principle. Before any two electrons occupy an orbital in a subshell, other orbitals in the same subshell must first each contain one electron. Also, the electrons filling a subshell will have parallel spin before the shell starts filling up with the opposite spin electrons (after the first orbital gains a second electron).
|
|
Iron[pyridine(diimine)] catalysts contain a redox active ligand in which the central iron atom can coordinate with two simple, unfunctionalized olefin double bonds. The catalyst can be written as a resonance between a structure containing unpaired electrons with the central iron atom in the II oxidation state, and one in which the iron is in the 0 oxidation state. This gives it the flexibility to engage in binding the double bonds as they undergo a cyclization reaction, generating a cyclobutane structure via C-C reductive elimination; alternatively a cyclobutene structure may be produced by beta- hydrogen elimination. Efficiency of the reaction varies substantially depending on the alkenes used, but rational ligand design may permit expansion of the range of reactions that can be catalyzed.
|
|
Wood established his own group at ICRF and over the next decade, performed a series of biochemistry experiments to understand each step in the repair process by adding individual, purified proteins. Repair (particularly of UV-induced pyrimidine dimers)includes recognition of the damaged site (probably by sensing an unpaired bubble at the mutation site), nicking the DNA at upstream and downstream sites, excising the damaged DNA, then filling in the single- stranded DNA gap using a polymerase, with the opposite strand serving as a template for the proper sequence for the repair patch. Since multiple proteins are involved in NER, different XP patients may have different gene mutations (called "complementation groups" based on which enzyme is defective in the NER pathway).
|
|
The first to record such behavior was Dr Levick, in 1911 and 1912, but his notes were deemed too indecent for publication at the time; they were rediscovered and published in 2012. "The pamphlet, declined for publication with the official Scott expedition reports, commented on the frequency of sexual activity, auto-erotic behaviour, and seemingly aberrant behaviour of young unpaired males and females, including necrophilia, sexual coercion, sexual and physical abuse of chicks and homosexual behaviour," states the analysis written by Douglas Russell and colleagues William Sladen and David Ainley. "His observations were, however, accurate, valid and, with the benefit of hindsight, deserving of publication." Levick observed the Adélie penguins at Cape Adare, the site of the largest Adélie penguin rookery in the world.
|
|
However, when using the BamHI site located at position 198 one must be careful of the unpaired Cysteine residue (C201) that could cause problems during phage display if one is using a non- truncated version of pIII. An advantage of using pIII rather than pVIII is that pIII allows for monovalent display when using a phagemid (Ff-phage derived plasmid) combined with a helper phage. Moreover, pIII allows for the insertion of larger protein sequences (>100 amino acids) and is more tolerant to it than pVIII. However, using pIII as the fusion partner can lead to a decrease in phage infectivity leading to problems such as selection bias caused by difference in phage growth rate or even worse, the phage's inability to infect its host.
|
|
Carbyne molecules are generally found to be in electronic doublet states: the non-bonding electrons on carbon are arranged as one radical (unpaired electron) and one electron pair, leaving a vacant atomic orbital, rather than being a tri-radical (the quartet state). The simplest case is the CH radical, which has an electron configuration 1σ2 2σ2 3σ2 1π. Here the 1σ molecular orbital is essentially the carbon 1s atomic orbital, and the 2σ is the C-H bonding orbital formed by overlap of a carbon s-p hybrid orbital with the hydrogen 1s orbital. The 3σ is a carbon non-bonding orbital pointing along the C-H axis away from the hydrogen, while there are two non- bonding 1π orbitals perpendicular to the C-H axis.
|
|
Even so, at just four millimetres in length, the fry are practically invisible against typical aquarium gravel unless seen to move. The fry take approximately four weeks to develop to the point where the finfold, a continuous undifferentiated membrane resembling that seen at the posterior of a tadpole, has differentiated into the unpaired fins (dorsal, anal and caudal fins). During this time, size will have increased to approximately eight or nine millimetres, and the fish will begin to develop colour changes leading to that of the adult fish. From this point, the caudal peduncle patch and dorsal fin patch will begin to appear, but the body will also be seen to be covered in fine black 'pepper dots' between these black patches.
|
|
The bilaterally symmetric sympathetic chain ganglia, also called the paravertebral ganglia, are located just ventral and lateral to the spinal cord. The chain extends from the upper neck down to the coccyx, forming the unpaired coccygeal ganglion. Each ganglia within this chain are either cervical, thoracic, lumbar, or sacral. Preganglionic nerves from the spinal cord synapse at one of the chain ganglia, and the postganglionic fiber extends to an effector, a visceral organ in the thoracic cavity, abdominal cavity, or pelvic cavity. There are usually 22-23 pairs of these ganglia: 3 in the cervical region (cervical ganglia), 11 in the thoracic region (note the presence of the stellate cervicothoracic ganglia), 4 in the lumbar region and 4-5 in the sacral region.
|
|
The Fenton reaction is possible because transition metals can exist in more than one oxidation state and their valence electrons may be unpaired, allowing them to participate in one-electron redox reactions. :::Fe2+ \+ H2O2 → Fe3+ \+ OH· + OH− The creation of hydroxyl radicals by iron(II) catalysis is important because iron(II) can be found coordinated with, and therefore in close proximity to, DNA. This reaction allows for hydrogen peroxide created by radiolysis of water to diffuse to the nucleus and react with Iron (II) to produce hydroxyl radicals, which in turn react with DNA. The location and binding of Iron (II) to DNA may play an important role in determining the substrate and nature of the radical attack on the DNA.
|
|
A line of lacZ reporter mice (mice that have E. coli's gene attached to their CREB gene to produce a protein that is easily visualized), when trained with a context protocol, showed higher levels of CREB-mediated transcription in the CA1 and CA3 regions of the hippocampus when compared to untrained mice or mice that did not associated content with shock (in fear conditioning) due to latent inhibition. Likewise, the lacZ mice that were trained with a tone protocol showed higher levels of CREB-dependent gene transcription in the amygdala than either mice with no training or mice in the unpaired group. There was no difference in CREB- dependent gene expression in the hippocampus of animals trained with a tone protocol.
|
|
In organisms that perform oxygenic photosynthesis, excess light may lead to photoinhibition, or photoinactivation of the reaction centers, a process that does not necessarily involve chemical damage. When photosynthetic antenna pigments such as chlorophyll are excited by light absorption, unproductive reactions may occur by charge transfer to molecules with unpaired electrons. Because oxygenic phototrophs generate O2 as a byproduct from the photocatalyzed splitting of water (H2O), photosynthetic organisms have a particular risk of forming reactive oxygen species. Therefore, a diverse suite of mechanisms have developed in photosynthetic organisms to mitigate these potential threats, which become exacerbated under high irradiance, fluctuating light conditions, in adverse environmental conditions such as cold or drought, and while experiencing nutrient deficiencies which cause an imbalance between energetic sinks and sources.
|
|
In statistics, Welch's t-test, or unequal variances t-test, is a two-sample location test which is used to test the hypothesis that two populations have equal means. It is named for its creator, Bernard Lewis Welch, and is an adaptation of Student's t-test, and is more reliable when the two samples have unequal variances and/or unequal sample sizes. These tests are often referred to as "unpaired" or "independent samples" t-tests, as they are typically applied when the statistical units underlying the two samples being compared are non-overlapping. Given that Welch's t-test has been less popular than Student's t-test and may be less familiar to readers, a more informative name is "Welch's unequal variances t-test" — or "unequal variances t-test" for brevity.
|
|
Unlike scorpions, solifugids do not have a third tagma that forms a "tail". There is currently neither fossil nor embryological evidence that arachnids ever had a separate thorax-like division, so the validity of the term cephalothorax, which means a fused cephalon, or head, and thorax, has been questioned. There are also arguments against use of 'abdomen', as the opisthosoma of many arachnids contains organs atypical of an abdomen, such as a heart and respiratory organs. Like pseudoscorpions and harvestmen, the Solifugae lack book lungs, having instead a well-developed tracheal system that inhales and exhales air through a number of spiracles; one pair between the second and third pair of walking legs, two pairs on the abdomen on abdominal segments three and four, and an unpaired spiracle on the fifth abdominal segment.
|
|
This relationship is indicated by several synapomorphies, such as: adult wing venation with costal brace (absent in other winged insects), larvae with 7 pairs of abdominal gills (compared to still 9 pairs in Permoplectoptera like Protereisma larvae), and with single- segmented tarsus with unpaired claw (compared to 3-segmented tarsus with paired claw in Permoplectoptera like Protereisma larvae). Together with mayflies and dragonflies they belong to the clade Palaeoptera, which is characterized by a derived wing articulation with fused sclerites, a vertical resting position of the wings in the groundplan, and a wing venation with intercalary veins between the main longitudinal veins (esp. IR1+ between RP1- and RP2-, and IR2+ between RP2- and RP3/4-). Because of some very primitive character states, the Coxoplectoptera rather looked like early Paleozoic ancestors of mayflies, e.g.
|
|
It is also possible that rather than a peak at a specific proton shell, there exists a plateau of proton shell effects from Z = 114–126. The island of stability near 298Fl is predicted to enhance stability for its constituent nuclei, especially against spontaneous fission as a consequence of greater fission barrier heights near the shell closure. Due to the expected high fission barriers, any nucleus within this island of stability will exclusively decay by alpha emission, and as such, the nucleus with the longest half-life may be 298Fl; predictions for the half-life of this nucleus range from minutes to billions of years. It may be possible, however, that the longest living nucleus is not 298Fl, but rather 297Fl (with N = 183) has a longer half-life due to the unpaired neutron.
|
|
Males grow to a maximum total length , of which the tail is in length. Females reach a maximum total length of , with a tail length of .Leviton AE, Wogan GOU, Koo MS, Zug GR, Lucas RS, Vindum JV. 2003. The Dangerously Venomous Snakes of Myanmar, Illustrated Checklist with Keys. Proc. Cal. Acad. Sci. 54 (24): 407-462. Scalation: dorsal scales in 23-25 longitudinal rows at midbody; first upper labial partially or completely fused to nasal; 9-13 upper labials, 1-2 rows of scales separate upper labials from the suboculars; 11-14 scales in a line between supraoculars; supraoculars rarely divided; temporal scales small, strongly keeled; ventral scales: males 153-174, females: 151-180; subcaudals: males 62-79, females 49-61, usually paired, occasionally unpaired shields present among paired series.
|
|
The VSEPR theory can be extended to molecules with an odd number of electrons by treating the unpaired electron as a "half electron pair" — for example, Gillespie and Nyholm suggested that the decrease in the bond angle in the series (180°), NO2 (134°), (115°) indicates that a given set of bonding electron pairs exert a weaker repulsion on a single non-bonding electron than on a pair of non-bonding electrons. In effect, they considered nitrogen dioxide as an AX2E0.5 molecule, with a geometry intermediate between and . Similarly, chlorine dioxide (ClO2) is an AX2E1.5 molecule, with a geometry intermediate between and . Finally, the methyl radical (CH3) is predicted to be trigonal pyramidal like the methyl anion (), but with a larger bond angle (as in the trigonal planar methyl cation ()).
|
|
Proton NMR is often used by the synthetic organic chemist because protons associated with certain functional groups give characteristic absorption energies, but NMR spectroscopy can also be performed on isotopes of nitrogen, carbon, fluorine, phosphorus, boron, and a host of other elements. In addition to simple absorption experiments, it is also possible to determine the rate of fast atom exchange reactions through suppression exchange measurements, interatomic distances through multidimensional nuclear overhauser effect experiments, and through-bond spin- spin coupling through homonuclear correlation spectroscopy. In addition to the spin excitation properties of nuclei, it is also possible to study the properties of organic radicals through the same fundamental technique. Unpaired electrons also have a net spin, and an external magnetic field allows for the extraction of similar information through electron paramagnetic resonance (EPR) spectroscopy.
|
|
The structure floats with its arms open wide. They can be pulled shut by adding a fourth strand of DNA (D) "programmed" to stick to both of the dangling, unpaired sections of strands B and C. The closing of the tweezers was proven by tagging strand A at either end with light-emitting molecules that do not emit light when they are close together. To re-open the tweezers add a further strand (E) with the right sequence to pair up with strand D. Once paired up, they have no connection to the machine BAC, so float away. The DNA machine can be opened and closed repeatedly by cycling between strands D and E. These tweezers can be used for removing drugs from inside fullerenes as well as from a self assembled DNA tetrahedron.
|
|
It lives in clear water areas of lagoons and shallow reefs, inhabiting waters from 1 to 50 meters (usually above 15m), and makes its home under ledges, in holes, and in between the spines of sea urchins. Coral reef fish settlement tends to be dominated by larval recruitment, but in at least part of Australia's Great Barrier Reef, around one third of recruitment of O. cyanosoma at any given coral reef patch tends to be by adult and juvenile migration across intervening sand and coral debris. Within the large aggregations in which O. cyanosoma prefers, stable male-female pairs are often found. Individuals in pairs are more likely to live in one site, and to be able to return to that site if removed (with or without their partner), than are unpaired individuals.
|
|
A variety of water models exist with increasing levels of complexity, representing water as a simple hard sphere (a united-atom model), as three separate particles with fixed bond angles, or even as four or five separate interaction centers to account for unpaired electrons on the oxygen atom. As water models grow more complex, related simulations grow more computationally intensive. A compromise method has been found in implicit solvation, which replaces the explicitly represented water molecules with a mathematical expression that reproduces the average behavior of water molecules (or other solvents such as lipids). This method is useful to prevent artifacts that arise from vacuum simulations and reproduces bulk solvent properties well, but cannot reproduce situations in which individual water molecules have interesting interactions with the molecules under study.
|
|
The specific name validus means "strong" in Latin, possibly in reference to the thick skull-roof. Because the species was based on multiple specimens (a syntype series), CMN 515 was designated as the lectotype specimen by John Bell Hatcher in 1907. As no similar remains had been found in the area before, Lambe was unsure of what kind of dinosaur they were, and whether they represented one species or more; he suggested the domes were "prenasals" situated before the nasal bones on the midline of the head, and noted their similarity to the nasal horn-core of a Triceratops specimen. In 1903, Hungarian palaeontologist Franz Nopcsa von Felső-Szilvás suggested that the fragmentary domes of Stegoceras were in fact frontal and nasal bones, and that the animal would therefore have had a single, unpaired horn.
|
|
The correlation of the spin density in the valence s orbital (calculated by the ratio of the isotropic hyperfine coupling constant to the theoretical hyperfine splitting in a pure s orbital) against the g-shift (normalized by the spin-orbit coupling constant). (Black) Si, (Blue) Ge, (Red) Sn, and (Green) Pb. (Circles), (Triangles), (Square). Spin-orbit coupling constants from Electron paramagnetic resonance has been paramount for the study of trivalent tetrels as the hyperfine coupling to the tetrel reveals the orbital in which the unpaired electron resides, and the orbital composition directly correlates to the structure of the molecule. The isotropic component of the hyperfine coupling to the central tetrel scales proportionally with the spin density in the valence s orbital on that atom (see the Figure on the right).
|
|
On average 2-5 random base pairs are added to each 3' end generated after the action of the Artemis complex. The number of bases added is enough for the two newly synthesized ssDNA segments to undergo microhomology alignment during non-homologous end joining according to the normal Watson-Crick base pairing patterns (A-T, C-G). From there unpaired nucleotides are excised by an exonuclease, like the Artemis Complex (which has exonuclease activity in addition to endonuclease activity), and then template-dependent polymerases can fill the gaps, finally creating the new coding joint with the action of ligase to combine the segments. Although TdT does not discriminate among the four base pairs when adding them to the N-nucleotide segments, it has shown a bias for guanine and cytosine base pairs.
|
|
In statistics, a paired difference test is a type of location test that is used when comparing two sets of measurements to assess whether their population means differ. A paired difference test uses additional information about the sample that is not present in an ordinary unpaired testing situation, either to increase the statistical power, or to reduce the effects of confounders. Specific methods for carrying out paired difference tests are, for normally distributed difference t-test (where the population standard deviation of difference is not known) and the paired Z-test (where the population standard deviation of the difference is known), and for differences that may not be normally distributed the Wilcoxon signed-rank test. The most familiar example of a paired difference test occurs when subjects are measured before and after a treatment.
|
|
In nature, the incorporation of a deoxyribonucleoside triphosphate (dNTP) into a growing DNA strand involves the formation of a covalent bond and the release of pyrophosphate and a positively charged hydrogen ion.Purushothaman, S, Toumazou, C, Ou, C-P Protons and single nucleotide polymorphism detection: a simple use for the ion sensitive field effect transistor A dNTP will only be incorporated if it is complementary to the leading unpaired template nucleotide. Ion semiconductor sequencing exploits these facts by determining if a hydrogen ion is released upon providing a single species of dNTP to the reaction. Microwells on a semiconductor chip that each contain many copies of one single-stranded template DNA molecule to be sequenced and DNA polymerase are sequentially flooded with unmodified A, C, G or T dNTP.
|
|
Although the nearly free electron approximation is able to describe many properties of electron band structures, one consequence of this theory is that it predicts the same number of electrons in each unit cell. If the number of electrons is odd, we would then expect that there is an unpaired electron in each unit cell, and thus that the valence band is not fully occupied, making the material a conductor. However, materials such as CoO that have an odd number of electrons per unit cell are insulators, in direct conflict with this result. This kind of material is known as a Mott insulator, and requires inclusion of detailed electron-electron interactions (treated only as an averaged effect on the crystal potential in band theory) to explain the discrepancy.
|
|
Thus, the t2g shell is filled, and the eg shell contains 3 electrons. Overall the unpaired electron produces a 2Eg state, which is Jahn–Teller active. The third electron can occupy either of the orbitals comprising the eg shell: the mainly 3z^2-r^2 orbital or the mainly x^2-y^2 orbital. If the electron occupies the mainly 3z^2-r^2 level, which antibonding orbital the final geometry of the complex would be elongated as the axial ligands will be pushed away to reduce the global energy of the system. On the other hand, if the electron went into the mainly x^2-y^2 antibonding orbital the complex would distort into a compressed geometry. Experimentally elongated geometries are overwhelmingly observed and this fact has been attributed both to metal-ligand anharmonic interactions and 3d-4s hybridisations.
|
|
Magnetic complexes with magnetic memory that consist of iron oxide nanoparticles loaded with antitumor drug have additional advantages over conventional antitumor drugs due to their ability to be remotely controlled while targeting with a constant magnetic field and further strengthening of their antitumor activity by moderate inductive hyperthermia (below 40 °C). The combined influence of inhomogeneous constant magnetic and electromagnetic fields during nanotherapy has initiated splitting of electron energy levels in magnetic complex and unpaired electron transfer from iron oxide nanoparticles to anticancer drug and tumor cells. In particular, anthracycline antitumor antibiotic doxorubicin, the native state of which is diamagnetic, acquires the magnetic properties of paramagnetic substances. Electromagnetic radiation at the hyperfine splitting frequency can increase the time that radical pairs are in the triplet state and hence the probability of dissociation and so the concentration of free radicals.
|
|
The direction of the magnetic moment of any elementary particle is entirely determined by the direction of its spin, with the negative value indicating that any electron's magnetic moment is antiparallel to its spin. The net magnetic moment of any system is a vector sum of contributions from one or both types of sources. For example, the magnetic moment of an atom of hydrogen-1 (the lightest hydrogen isotope, consisting of a proton and an electron) is a vector sum of the following contributions: # the intrinsic moment of the electron, # the orbital motion of the electron around the proton, # the intrinsic moment of the proton. Similarly, the magnetic moment of a bar magnet is the sum of the contributing magnetic moments, which include the intrinsic and orbital magnetic moments of the unpaired electrons of the magnet's material and the nuclear magnetic moments.
|
|
The magnetic field produced by an atom—its magnetic moment—is determined by these various forms of angular momentum, just as a rotating charged object classically produces a magnetic field, but the most dominant contribution comes from electron spin. Due to the nature of electrons to obey the Pauli exclusion principle, in which no two electrons may be found in the same quantum state, bound electrons pair up with each other, with one member of each pair in a spin up state and the other in the opposite, spin down state. Thus these spins cancel each other out, reducing the total magnetic dipole moment to zero in some atoms with even number of electrons. In ferromagnetic elements such as iron, cobalt and nickel, an odd number of electrons leads to an unpaired electron and a net overall magnetic moment.
|
|
One objection to this interpretation is that the single midline postparietal of Ichthyostega has a transverse bend of the lateral line, which in fish typically occurs on extrascapular elements (plates at the back of the skull formed from enlarged neck scales). Proponents of the "orthodox" interpretation used this to argue that the unpaired postparietal of Icthyostega is a modified extrascapular element not homologous to what they identify as the "parietals" of fish. However, this is more easily explained by a simple shift in the position of the lateral line, as the postparietals of Icthyostega are otherwise identical in proportion and position (and therefore considered homologous) to the large paired posterior midline elements of fish. Many sarcopterygian fish (including living coelocanths) possess a large, robust plate at the back of the skull known as a postparietal shield.
|
|
Greenworld is a hypothetical Earth- like exoplanet with a diverse and thriving biosphere. All animal-analogous organisms on Greenworld are descended from a radially symmetrical six-legged starfish-like animal. Animals on Greenworld secondarily developed bilateral symmetry (which is what is seen in most animals on Earth), developing into two major groups; “sulcosyms” in which the plane of symmetry lies between the legs (meaning they have three pairs of limbs) and “brachiosyms” in which the plane of symmetry has led to the formation of one “arm” at each of its ends (meaning two pairs of limbs and two unpaired limbs, one at the front and one at the back). In the book, humanity discovers Greenworld just as Earth finally collapses under the pressure of mankind's impact and a generation ship with ten thousand people is sent to colonize the planet.
|
|
The Unicode standard permanently reserves these code point values for UTF-16 encoding of the high and low surrogates, and they will never be assigned a character, so there should be no reason to encode them. The official Unicode standard says that no UTF forms, including UTF-16, can encode these code points. However, UCS-2, UTF-8, and UTF-32 can encode these code points in trivial and obvious ways, and a large amount of software does so even though the standard states that such arrangements should be treated as encoding errors. It is possible to unambiguously encode an unpaired surrogate (a high surrogate code point not followed by a low one, or a low one not preceded by a high one) in UTF-16 by using a code unit equal to the code point.
|
|
Once a metal complex undergoes metal-to-ligand charge transfer, the system can undergo intersystem crossing, which, in conjunction with the tunability of MLCT excitation energies, produces a long-lived intermediate whose energy can be adjusted by altering the ligands used in the complex. Another species can then react with the long-lived excited state via oxidation or reduction, thereby initiating a redox pathway via tunable photoexcitation. Complexes containing high atomic number d6 metal centers, such as Ru(II) and Ir(III), are commonly used for such applications due to them favoring intersystem crossing as a result of their more intense spin-orbit coupling. Complexes that have access to d orbitals are able to access spin multiplicities besides the singlet and triplet states, as some complexes have orbitals of similar or degenerate energies so that it is energetically favorable for electrons to be unpaired.
|
|
In 1933, Aleksander Jabłoński published his conclusion that the extended lifetime of phosphorescence was due to a metastable excited state at an energy lower than the state first achieved upon excitation. Based upon this research, Gilbert Lewis and coworkers, during their investigation of organic molecule luminescence in the 1940s, concluded that this metastable energy state corresponded to the triplet electron configuration. The triplet state was confirmed by Lewis via application of a magnetic field to the excited phosphor, as only the metastable state would have a long enough lifetime to be analyzed and the phosphor would have only responded if it was paramagnetic due to it having at least one unpaired electron. Their proposed pathway of phosphorescence included the forbidden spin transition occurring when the potential energy curves of the singlet excited state and the triplet excited state crossed, from which the term intersystem crossing arose.
|
|
As a stable and well- characterized solid radical source, DPPH is the traditional and perhaps the most popular standard of the position (g-marker) and intensity of electron paramagnetic resonance (EPR) signals – the number of radicals for a freshly prepared sample can be determined by weighing and the EPR splitting factor for DPPH is calibrated at g = 2.0036. DPPH signal is convenient by that it is normally concentrated in a single line, whose intensity increases linearly with the square root of microwave power in the wider power range. The dilute nature of the DPPH radicals (one unpaired spin per 41 atoms) results in a relatively small linewidth (1.5–4.7 Gauss). The linewidth may however increase if solvent molecules remain in the crystal and if measurements are performed with a high-frequency EPR setup (~200 GHz), where the slight g-anisotropy of DPPH becomes detectable.
|
|
The methods by which one can elucidate the structure of a molecule include spectroscopies such as nuclear magnetic resonance (proton and carbon-13 NMR), various methods of mass spectrometry (to give overall molecular mass, as well as fragment masses), and x-ray crystallography when applicable. The last technique can produce three-dimensional models at atomic- scale resolution, as long as crystals are available. When a molecule has an unpaired electron spin in a functional group of its structure, ENDOR and electron-spin resonance spectroscopes may also be performed. Techniques such as absorption spectroscopy and the vibrational spectroscopies, infrared and Raman, provide, respectively, important supporting information about the numbers and adjacencies of multiple bonds, and about the types of functional groups (whose internal bonding gives vibrational signatures); further inferential studies that give insight into the contributing electronic structure of molecules include cyclic voltammetry and X-ray photoelectron spectroscopy.
|
|
A page from the 1470 Ulrich Han printing of Plutarch's Parallel Lives Plutarch's best-known work is the Parallel Lives, a series of biographies of illustrious Greeks and Romans, arranged in pairs to illuminate their common moral virtues and vices, thus it being more of an insight into human nature than a historical account. The surviving Lives contain 23 pairs, each with one Greek Life and one Roman Life, as well as four unpaired single Lives. As is explained in the opening paragraph of his Life of Alexander, Plutarch was not concerned with history so much as the influence of character, good or bad, on the lives and destinies of men. Whereas sometimes he barely touched on epoch- making events, he devoted much space to charming anecdote and incidental triviality, reasoning that this often said far more for his subjects than even their most famous accomplishments.
|
|
Molecular orbital diagram of dinitrogen molecule, N2. There are five bonding orbitals and two antibonding orbitals (marked with an asterisk; orbitals involving the inner 1s electrons not shown), giving a total bond order of three. Atomic nitrogen, also known as active nitrogen, is highly reactive, being a triradical with three unpaired electrons. Free nitrogen atoms easily react with most elements to form nitrides, and even when two free nitrogen atoms collide to produce an excited N2 molecule, they may release so much energy on collision with even such stable molecules as carbon dioxide and water to cause homolytic fission into radicals such as CO and O or OH and H. Atomic nitrogen is prepared by passing an electric discharge through nitrogen gas at 0.1–2 mmHg, which produces atomic nitrogen along with a peach-yellow emission that fades slowly as an afterglow for several minutes even after the discharge terminates.
|
|
Like most other Western Oti–Volta languages, it has lost the complicated noun class agreement system still found in e.g. the more distantly related Gurmanche, and has only a natural gender system, human/non-human. The noun classes are still distinguishable in the way nouns distinguish singular from plural by paired suffixes: nid(a) "person" plural nidib(a) buug(a) "goat" plural buus(e) nobir(e) "leg, foot" plural noba(a) fuug(o) "item of clothing" plural fuud(e) molif(o) "gazelle" plural moli(i) A unpaired suffix -m(m) is found with many uncountable and abstract nouns, e.g. ku'om(m) "water" The bracketed final vowels in the examples occur because of the feature which most strikingly separates Kusaal from its close relatives: the underlying forms of words, such as buuga "goat" are found only when the word in question is the last word in a question or a negated statement.
|
|
Song, recorded at Diaccia Botrona marsh (Italy) Song, recorded at Macta marsh (Algeria) Sonogram of Great reed warbler's song, recorded at Macta marsh (Algeria) Great reed warbler (Kyiv, Ukraine) Male great reed warblers have been observed to communicate via two basic song types: short songs about one second in length with few syllables, and long songs of about four seconds that have more syllables and are louder than the short variety. It has been observed that long songs are primarily used by males to attract females; long songs are only given spontaneously by unpaired males, and cease with the arrival of a female. Short songs, however, are primarily used in territorial encounters with rival males. During experimental observation, male great reed warblers showed reluctance to approach recordings of short songs, and when lured in by long songs, would retreat when playback was switched to short songs.
|
|
The anatomy of the female reproductive system: S. maritima resembles closely that described for other genera by Fabre (1855) and Schaufler (1889), consisting of an unpaired tubular ovary leading to a short oviduct which divides to pass round the gut, fusing again to open ventrally into the subterminal genital atrium. There is a short pair of accessory glands, and in the prepenultimate pediferous segment there is a pair of spherical receptacula semines the convoluted ducts of which open into the genital atrium along with the accessory glands. After Lewis’s analysis in 1968, about the widths of oocytes in the adolescent female S. maritima, it seems that the matures females are fertilized in May before laying their eggs, but the newly recruited maturus juniors are fertilized soon after the moult that produces them in August. In August, the males contain only small quantities of sperm.
|
|
A couple years later, the legislature declined another offer by the Lehigh Coal and Navigation Company (LC&N;) which had built the Lehigh Canal with private funds. LC&N; was unquestionably one of the most innovative companies of the era, driving the mining, transportation and industrial development of Pennsylvania by example, implementation, and by funding quite a few projects, as well. This new proposal was to build--at the companies expense-- the project that would (in concept) become their version of the eventual Delaware Canal (alternatively the 'Delaware Division of the Pennsylvania Canal') built by the states engineering managers a few years later. The route was nearly the same, but the Delaware Canal as the state built it had numerous engineering flaws, including locks both too short and unpaired (single & supporting only one way traffic) locks LC&N;'s experience and expertise would have mitigated.
|
|
Pressed for space as Kolkata developed, and lacking adequate government funding, the zoo attracted a lot of controversy in the latter half of the 20th century due to cramped living conditions of the animals, lack of initiative at breeding rare species, and for cross-breeding experiments between species. The zoo has also, in the past, attracted a lot of criticism for keeping single and unpaired specimens of rare species like the banteng, great Indian one-horned rhinoceros, crowned crane and the lion-tailed macaque.Somdatta Basu, Endangered singles bug matchmakers, Times of India, 10 August 2005 Lack of breeding and exchange programs has led to the elimination of individuals and populations of environmentally vulnerable species like the southern cassowary, wild yak, giant eland, slow loris and echidna. The previously cramped, unsuitable and unhygienic conditions inside the cages, and in the zoo in general had been criticized for long.
|
|
The electric dipole moment of the dioxygen molecule, is zero, but the molecule is paramagnetic with two unpaired electrons so that there are magnetic-dipole allowed transitions which can be observed by microwave spectroscopy. The unit electron spin has three spatial orientations with respect to the given molecular rotational angular momentum vector, K, so that each rotational level is split into three states, J = K + 1, K, and K - 1, each J state of this so-called p-type triplet arising from a different orientation of the spin with respect to the rotational motion of the molecule. The energy difference between successive J terms in any of these triplets is about 2 cm−1 (60 GHz), with the single exception of J = 1←0 difference which is about 4 cm−1. Selection rules for magnetic dipole transitions allow transitions between successive members of the triplet (ΔJ = ±1) so that for each value of the rotational angular momentum quantum number K there are two allowed transitions.
|
|
Lemon tetras exhibit an interesting behaviour pattern in the aquarium, replicated by several other characin species, in which males will adopt 'landmarks' within the aquarium and use these as places from which to display as maturity approaches. Displays are principally performed between rival males, which position themselves in a slightly head-up posture, unpaired fins held erect to appear as large and as imposing as possible, and swim forwards with 'flicking' movements of the body. If two rival males approach closely, they will then begin to make passes at each other, which to the causal observer look like attacks: this is an entirely ritualised behaviour, best referred to as 'jousting', where the males make darting movements toward each other but pull away at the last moment. No damage is incurred by either contestant in these events, and evenly matched males that are at a similar level in the social hierarchy will continue such behaviour for 30 minutes or more at a time.
|
|
It therefore has five valence electrons in the 2s and 2p orbitals, three of which (the p-electrons) are unpaired. It has one of the highest electronegativities among the elements (3.04 on the Pauling scale), exceeded only by chlorine (3.16), oxygen (3.44), and fluorine (3.98). (The light noble gases, helium, neon, and argon, would presumably also be more electronegative, and in fact are on the Allen scale.) Following periodic trends, its single- bond covalent radius of 71 pm is smaller than those of boron (84 pm) and carbon (76 pm), while it is larger than those of oxygen (66 pm) and fluorine (57 pm). The nitride anion, N3−, is much larger at 146 pm, similar to that of the oxide (O2−: 140 pm) and fluoride (F−: 133 pm) anions. The first three ionisation energies of nitrogen are 1.402, 2.856, and 4.577 MJ·mol−1, and the sum of the fourth and fifth is 16.920 MJ·mol−1.
|
|
Studying egg tissue and the fertilization process in aphids, mealworms, beetles, and flies, Stevens saw that there were chromosomes that existed in small-large pairs (now known as XY chromosome pairs) and she also saw chromosomes that were unpaired, XO. Hermann Henking had studied firebug chromosomes earlier and noticed the chromosome now called X, but didn't find the small chromosome now called Y. Stevens realized that the previous idea of Clarence Erwin McClung, that the X chromosome determines sex, was wrong and that sex determination is, in fact, due to the presence or absence of the small (Y) chromosome. Stevens did not name the chromosomes X or Y. Their current names came later.David Bainbridge, 'The X in Sex: How the X Chromosome Controls Our Lives, pages 3-5, 13, Harvard University Press, 2003 .James Schwartz, In Pursuit of the Gene: From Darwin to DNA, pages 170-172, Harvard University Press, 2009 Edmund Wilson worked on spermatogenesis preparations simultaneously with Stevens' studies.
|
|
Still, in most cases, catalysts are necessary for substitution reactions to occur. The cyclopentadienyl anion () with six π electrons is planar and readily generated from the unusually acidic cyclopentadiene (pKa 16), while the corresponding cation with four π electrons is destabilized, being harder to generate than a typical acyclic pentadienyl cations and is thought to be antiaromatic. Similarly, the tropylium cation (), also with six π electrons, is so stable compared to a typical carbocation that its salts can be crystallized from ethanol. On the other hand, in contrast to cyclopentadiene, cycloheptatriene is not particularly acidic (pKa 37) and the anion is considered nonaromatic. The cyclopropenyl cation () and the triboracyclopropenyl dianion () are considered examples of a two π electron system, which are stabilized relative to the open system, despite the angle strain imposed by the 60° bond angles. Planar ring molecules with 4n π electrons do not obey Hückel's rule, and theory predicts that they are less stable and have triplet ground states with two unpaired electrons.
|
|
Tarsophlebia eximia, Upper Jurassic, Solnhofen Plattenkalk, cerci of male specimen MCZ 6222 Males are distinguished by paddle-like cerci, while females are distinguished by very long and thin, hypertrophied ovipositor that projects far beyond the abdomen. Tarsophlebia eximia, Upper Jurassic, Solnhofen Plattenkalk, secondary genital apparatus of male specimen JME SOS 1720 The male secondary genitalia were of a unique primitive type, with a small sperm vesicle on sternite 3, two pairs of small plate-like hamuli on sternite 2, and a very short median ligula on sternite 2. Obviously, none of these structures is hypertrophied as sperm intromittent organ (functional penis). In each of the three suborders of Recent odonates, a different part of this apparatus is enlarged and developed as intromittent organ and device for removal of foreign sperm (sperm competition): in Zygoptera it is the ligula, an median process of sternite 2; in Epiophlebiidae it is the lateral pair of posterior hamuli on segment 2; and in Anisoptera it is the unpaired sperm vesicle on the anterior part of sternite 3.
|
|
The few strictly conserved primary sequences are the consensus at the 5' and 3' splicing site (...↓GUGYG&... and ...AY↓..., with the Y representing a pyrimidine), some of the nucleotides of the central core (joiner sequences), a relatively high number of nucleotides of DV and some short-sequence stretches of DI. The unpaired adenosine in DVI (marked by an asterisk in the figure and located 7 or 8 nt away from the 3' splicing site) is also conserved and plays a central role in the splicing process. The 2' hydroxyl of the bulged adenosine attacks the 5' splice site, followed by nucleophilic attack on the 3' splice site by the 3' OH of the upstream exon. This results in a branched intron lariat connected by a 2' phosphodiester linkage at the DVI adenosine. Protein machinery is required for splicing in vivo, and long-range intron-intron and intron-exon interactions are important for splice site positioning, as well as a number of tertiary contacts between motifs, including kissing-loop and tetraloop-receptor interactions.
|
|
A bijective function, f: X → Y, where set X is {1, 2, 3, 4} and set Y is {A, B, C, D}. For example, f(1) = D. In mathematics, a bijection, bijective function, one-to-one correspondence, or invertible function, is a function between the elements of two sets, where each element of one set is paired with exactly one element of the other set, and each element of the other set is paired with exactly one element of the first set. There are no unpaired elements. In mathematical terms, a bijective function is a one-to-one (injective) and onto (surjective) mapping of a set X to a set Y. The term one- to-one correspondence must not be confused with one-to-one function (an injective function; see figures). A bijection from the set X to the set Y has an inverse function from Y to X. If X and Y are finite sets, then the existence of a bijection means they have the same number of elements.
|
|
The Compatibility Encoding Scheme for UTF-16: 8-Bit (CESU-8) is a variant of UTF-8 that is described in Unicode Technical Report #26. A Unicode code point from the Basic Multilingual Plane (BMP), i.e. a code point in the range U+0000 to U+FFFF, is encoded in the same way as in UTF-8. A Unicode supplementary character, i.e. a code point in the range U+10000 to U+10FFFF, is first represented as a surrogate pair, like in UTF-16, and then each surrogate code point is encoded in UTF-8. Therefore, CESU-8 needs six bytes (3 bytes per surrogate) for each Unicode supplementary character while UTF-8 needs only four. Though not specified in the technical report, unpaired surrogates are also encoded as 3 bytes each, and CESU-8 is exactly the same as applying an older UCS-2 to UTF-8 converter to UTF-16 data. The encoding of Unicode non-BMP characters works out to `11101101 1010yyyy 10xxxxxx 11101101 1011xxxx 10xxxxxx` (yyyy represents the top five bits of the character minus one).The byte value 0xF0 will not appear in CESU-8, as it starts the 4-byte encoding used by UTF-8.
|
|
Russian folk dance (Russian: Русский Народный Танец ) can generally be broken up into two main types of dances Khorovod (Russian: Хоровод), a circular game type dance where the participants hold hands, sing, and the action generally happens in the middle of circle, and Plyaska (Russian: Пляска or Плясовый), a circular dance for men and women that increases in diversity and tempo, according to Bob Renfield, considered to be the preeminent scholar on the topic. Other forms of Russian Folk Dance include Pereplyas (Russian: Перепляс), an all-male competitive dance, Mass Dance (Russian: Массовый пляс), an unpaired stage dance without restrictions on age or number of participants, Group Dance (Russian: Групповая пляска) a type of mass dance employs simple round-dance passages, and improvisation, and types of Quadrilles (Russian: Кадриль), originally a French dance brought to Russia in the 18th century. Squat dance by Russian dancer Ethnic Russian dances include khorovod (Russian: Хоровод), barynya (Russian: Барыня), kamarinskaya (Russian: Камаринская), kazachok (Russian: Казачок) and chechotka (Russian: Чечётка) (a tap dance in bast shoes and with a bayan).Russian chechotka Troika (Russian: Тройка) A dance with one man and two women, named after the traditional Russian carriage which is led by three horses.
|
|