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Anomalous
Anomaly may refer to: Science Natural *Anomaly (natural sciences) ** Atmospheric anomaly **Geophysical anomaly Medical * Congenital anomaly (birth defect), a disorder present at birth ** Physical anomaly, a deformation of an anatomical structure *** Congenital vertebral anomaly, any of several malformations of the spine ** Collie eye anomaly, eye disease of dogs ***Coronary artery anomaly, a congenital abnormality in the heart *** Ebstein's anomaly, a congenital heart defect in which the opening of the tricuspid valve is displaced ***Uhl anomaly, a congenital heart disease affecting the myocardial muscle ***Vaginal anomalies Biology * Anomalous, a species of moth in the Noctuid family *Chromosome anomaly, a disorder caused by a structural error in a chromosome or an atypical number of chromosomes *Genetic anomaly, a disorder caused by mutation *Teratology, the study of developmental anomalies Physics * Anomalous diffusion is the movement of molecules from a region of lower co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomalous Diffusion
Anomalous diffusion is a diffusion process with a non-linear relationship between the mean squared displacement (MSD), \langle r^(\tau )\rangle , and time. This behavior is in stark contrast to Brownian motion, the typical diffusion process described by Einstein and Smoluchowski, where the MSD is linear in time (namely, \langle r^(\tau )\rangle =2dD\tau with ''d'' being the number of dimensions and ''D'' the diffusion coefficient). Examples of anomalous diffusion in nature have been observed in biology in the cell nucleus, plasma membrane and cytoplasm. Unlike typical diffusion, anomalous diffusion is described by a power law, \langle r^(\tau )\rangle =K_\alpha\tau^\alphawhere K_\alpha is the so-called generalized diffusion coefficient and \tau is the elapsed time. In Brownian motion, α = 1. If α > 1, the process is superdiffusive. Superdiffusion can be the result of active cellular transport processes or due to jumps with a heavy-tail distribution. If α < 1, the parti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiral Anomaly
In theoretical physics, a chiral anomaly is the anomalous nonconservation of a chiral current. In everyday terms, it is equivalent to a sealed box that contained equal numbers of left and right-handed bolts, but when opened was found to have more left than right, or vice versa. Such events are expected to be prohibited according to classical conservation laws, but it is known there must be ways they can be broken, because we have evidence of charge–parity non-conservation ("CP violation"). It is possible that other imbalances have been caused by breaking of a ''chiral law'' of this kind. Many physicists suspect that the fact that the observable universe contains more matter than antimatter is caused by a chiral anomaly. Research into chiral symmetry breaking laws is a major endeavor in particle physics research at this time. Informal introduction The chiral anomaly originally referred to the anomalous decay rate of the neutral pion, as computed in the current algebra of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flyby Anomaly
The flyby anomaly is a discrepancy between current scientific models and the actual increase in speed (i.e. increase in ''kinetic energy'') observed during a planetary flyby (usually of Earth) by a spacecraft. In multiple cases, spacecraft have been observed to gain greater speed than scientists had predicted, but thus far no convincing explanation has been found. This anomaly has been observed as shifts in the S-band and X-band Doppler and ranging telemetry. The largest discrepancy noticed during a flyby has been 13 mm/s. Observations Gravitational assists are valuable techniques for Solar System exploration. Because the success of such flyby maneuvers depends on the exact geometry of the trajectory, the position and velocity of a spacecraft during its encounter with a planet is continually tracked with great precision by the Deep Space Network (DSN). The flyby anomaly was first noticed during a careful inspection of DSN Doppler data shortly after the Earth flyby of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Artery Anomaly
Coronary artery anomalies are variations of the coronary circulation, affecting 1% of an unselected population - ''normal variant'': an alternative, unusual but benign morphological feature identified in >1% of the same population (e.g. left main is absent in 1-2% of the general population with LAD and LCx originating from separate ostia - “absent left trunk” variant) - ''coronary artery anomaly (CAA)'': a morphological feature seen in 50% increase of the vessel diameter. Some cases are congenital/idiopathic, but most are secondary to atherosclerosis or Kawasaki disease (an immuno-inflammatory disease especially targeting coronary vessels wall). Potential complications include localized thrombosis, distal embolization, rupture, or late lipid deposits. ''Coronary arteriovenous fistulas'' are anomalies at the termination consisting of an anomalous connection of coronary arteries to coronary veins, veins of the pulmonary or systemic circulations, or to any cardia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomaly (physics)
In quantum physics an anomaly or quantum anomaly is the failure of a symmetry of a theory's classical action to be a symmetry of any regularization of the full quantum theory. In classical physics, a classical anomaly is the failure of a symmetry to be restored in the limit in which the symmetry-breaking parameter goes to zero. Perhaps the first known anomaly was the dissipative anomaly in turbulence: time-reversibility remains broken (and energy dissipation rate finite) at the limit of vanishing viscosity. In quantum theory, the first anomaly discovered was the Adler–Bell–Jackiw anomaly, wherein the axial vector current is conserved as a classical symmetry of electrodynamics, but is broken by the quantized theory. The relationship of this anomaly to the Atiyah–Singer index theorem was one of the celebrated achievements of the theory. Technically, an anomalous symmetry in a quantum theory is a symmetry of the action, but not of the measure, and so not of the part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parity Anomaly
In theoretical physics a quantum field theory is said to have a parity anomaly if its classical action is invariant under a change of parity of the universe, but the quantum theory is not invariant. This kind of anomaly can occur in odd-dimensional gauge theories with fermions whose gauge groups have odd dual Coxeter numbers. They were first introduced by Antti J. Niemi and Gordon Walter Semenoff in the letterAxial-Anomaly-Induced Fermion Fractionization and Effective Gauge-Theory Actions in Odd-Dimensional Space-Times and by A. Norman Redlich in the letteGauge Noninvariance and Parity Nonconservation of Three-Dimensional Fermionsand the articlParity violation and gauge noninvariance of the effective gauge field action in three dimensions It is in some sense an odd-dimensional version of Edward Witten's SU(2) anomaly in 4-dimensions, and in fact Redlich writes that his demonstration follows Witten's. The anomaly in 3-dimensions Consider a classically parity-invariant g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomalous Dispersion
In optics, and by analogy other branches of physics dealing with wave propagation, dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency; sometimes the term chromatic dispersion is used for specificity to optics in particular. A medium having this common property may be termed a dispersive medium (plural ''dispersive media''). Although the term is used in the field of optics to describe light and other electromagnetic waves, dispersion in the same sense can apply to any sort of wave motion such as acoustic dispersion in the case of sound and seismic waves, and in gravity waves (ocean waves). Within optics, dispersion is a property of telecommunication signals along transmission lines (such as microwaves in coaxial cable) or the pulses of light in optical fiber. Physically, dispersion translates in a loss of kinetic energy through absorption. In optics, one important and familiar consequence of dispersion is the change in the angle of refra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anomalon
:Anomalon ''is also the type genus of the ichneumon-wasp subfamily Anomaloninae.'' See ''Anomalon (genus)''. In physics, an anomalon is a hypothetical type of nuclear matter that shows an anomalously large reactive cross section. They were first noticed in experimental runs in the early 1980s as short tracks in film emulsions or plastic leaf detectors connected to medium-energy particle accelerators. The direction of the tracks demonstrated that they were the results of reactions taking place within the accelerator targets, but they stopped so quickly in the detectors that no obvious explanation for their behavior could be offered. A flurry of theoretical explanations followed, but over time a series of follow-up experiments failed to find strong evidence for the anomalons, and active study of the topic largely ended by the late 1980s. Description Early particle accelerators generally consisted of three parts, the accelerator, a metal target, and some sort of detector. Detectors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teratology
Teratology is the study of abnormalities of physiological development in organisms during their life span. It is a sub-discipline in medical genetics which focuses on the classification of congenital abnormalities in dysmorphology. The related term developmental toxicity includes all manifestations of abnormal development that are caused by environmental insult. These may include growth retardation, delayed mental development or other congenital disorders without any structural malformations. Teratogens are substances that may cause birth defects via a toxic effect on an embryo or fetus. Known teratogens include: retinol, thalidomide, mercury, alcohol, lead, polychlorinated biphenyls (PCBs), and 2,3,7,8-tetrachlorodibenzodioxin. Etymology The term was borrowed in 1842 from the French , where it was formed in 1830 from the Greek (word stem ), meaning "sign sent by the gods, portent, marvel, monster", and ('' -ology''), used to designate a discourse, treaty, science, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stilbia Anomala
''Stilbia anomala'', the false footman or anomalous, is a moth of the family Noctuidae. It is found in parts of western Europe. Technical description and variation The wingspan is 29–36 mm. Forewing grey, shining; the costa suffused with dark fuscous; inner and outer lines double, blackish, filled in with whitish, irregularly dentate; subterminal pale with suffusedly darker edges; orbicular and reniform stigmata with pale annuli externally dark margined, separated by a diffuse dark shade, the former oblique and narrow; hindwing white tinged with brown along termen; in the female the forewing is more uniformly blackish fuscous; — the form ''philopalis'' Grasl. ow species ''Stilbia philopalis'' (Graslin, 1852) from S. E. France, is smaller, paler, with the markings showing up more prominently; - ''andalusica'' Stgr. ow species ''Stilbia andalusiaca'' Staudinger, [1892, a Spanish form, is also smaller than the typical, but with less distinct lines and markings; — in ''sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mixed Anomaly
In theoretical physics, a mixed anomaly is an example of an anomaly: it is an effect of quantum mechanics — usually a one-loop diagram — that implies that the classically valid general covariance and gauge symmetry of a theory of general relativity combined with gauge fields and fermionic fields cannot be preserved simultaneously in the quantum theory. The adjective "mixed" usually refers to a mixture of a gravitational anomaly and gauge anomaly, but may also refer to a mixture of two different gauge groups tensored together, like the ''SU(2)'' and the ''U(1)'' of the Standard Model. The anomaly usually appears as a Feynman diagram with a chiral fermion running in the loop (a polygon) with ''n−k'' external gravitons and ''k'' external gauge boson In particle physics, a gauge boson is a bosonic elementary particle that acts as the force carrier for elementary fermions. Elementary particles, whose interactions are described by a gauge theory, interact with each oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apsis
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any elliptic orbit. The name for each apsis is created from the prefixes ''ap-'', ''apo-'' (), or ''peri-'' (), each referring to the farthest and closest point to the primary body the affixing necessary suffix that describes the primary body in the orbit. In this case, the suffix for Earth is ''-gee'', so the apsides' names are ''apogee'' and ''perigee''. For the Sun, its suffix is ''-helion'', so the names are ''aphelion'' and ''perihelion''. According to Newton's laws of motion, all periodic orbits are ellipses. The barycenter of the two bodies may lie well within the bigger body—e.g., the Earth–Moon barycenter is about 75% of the way from Earth's center to its surface. If, compared to the larger mass, the smaller mass is negligible (e.g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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