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https://en.wikipedia.org/wiki/Small%20nucleolar%20RNA
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In molecular biology, small nucleolar RNAs (snoRNAs) are a class of small RNA molecules that primarily guide chemical modifications of other RNAs, mainly ribosomal RNAs, transfer RNAs and small nuclear RNAs. There are two main classes of snoRNA, the C/D box snoRNAs, which are associated with methylation, and the H/ACA box snoRNAs, which are associated with pseudouridylation.
SnoRNAs are commonly referred to as guide RNAs but should not be confused with the guide RNAs that direct RNA editing in trypanosomes or the guide RNAs (gRNAs) used by Cas9 for CRISPR gene editing.
snoRNA guided modifications
After transcription, nascent rRNA molecules (termed pre-rRNA) undergo a series of processing steps to generate the mature rRNA molecule. Prior to cleavage by exo- and endonucleases, the pre-rRNA undergoes a complex pattern of nucleoside modifications. These include methylations and pseudouridylations, guided by snoRNAs.
Methylation is the attachment or substitution of a methyl group onto various substrates. The rRNA of humans contain approximately 115 methyl group modifications. The majority of these are 2′O-ribose-methylations (where the methyl group is attached to the ribose group).
Pseudouridylation is the conversion (isomerisation) of the nucleoside uridine to a different isomeric form pseudouridine (Ψ). This modification consists of a 180º rotation of the uridine base around its glycosyl bond to the ribose of the RNA backbone. After this rotation, the nitrogenous base contributes a carbon atom to the glycosyl bond instead of the usual nitrogen atom. The beneficial aspect of this modification is the additional hydrogen-bond donor available on the base. While uridine makes two hydrogen-bonds with its Watson-Crick base pair, adenine, pseudouridine is capable of making three hydrogen bonds. When pseudouridine is base-paired with adenine, it can also make another hydrogen bond, allowing the complexity of the mature rRNA structure to take form. The free hydrogen-bond dono
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https://en.wikipedia.org/wiki/Gubernaculum%20testis
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In the inguinal crest of a peculiar structure, the gubernaculum testis makes its appearance. This is at first a slender band, extending from that part of the skin of the groin which afterward forms the scrotum through the inguinal canal to the body and epididymis of the testis. The gubernaculum testis is homologous to the round ligament of the uterus in females.
External links
Images
Embryology
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https://en.wikipedia.org/wiki/Matrox%20G200
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The G200 is a 2D, 3D, and video accelerator chip for personal computers designed by Matrox. It was released in 1998.
History
Matrox had been known for years as a significant player in the high-end 2D graphics accelerator market. Cards they produced were excellent Windows accelerators, and some of the later cards such as Millennium and Mystique excelled at MS-DOS as well. Matrox stepped forward in 1994 with their Impression Plus to innovate with one of the first 3D accelerator boards, but that card only could accelerate a very limited feature set (no texture mapping), and was primarily targeted at CAD applications.
Matrox, seeing the slow but steady growth in interest in 3D graphics on PCs with NVIDIA, Rendition, and ATI's new cards, began experimenting with 3D acceleration more aggressively and produced the Mystique. Mystique was their most feature-rich 3D accelerator in 1997, but still lacked key features including bilinear filtering. Then, in early 1998, Matrox teamed up with PowerVR to produce an add-in 3D board called Matrox m3D using the PowerVR PCX2 chipset. This board was one of the very few times that Matrox would outsource for their graphics processor, and was certainly a stop-gap measure to hold out until the G200 project was ready to go.
Overview
With the G200, Matrox aimed to combine its past products' competent 2D and video acceleration with a full-featured 3D accelerator. The G200 chip was used on several boards, most notably the Millennium G200 and Mystique G200. Millennium G200 received the new SGRAM memory and a faster RAMDAC, while Mystique G200 was cheaper and equipped with slower SDRAM memory but gained a TV-out port. Most G200 boards shipped standard with 8 MB RAM and were expandable to 16 MB with an add-on module. The cards also had ports for special add-on boards, such as the Rainbow Runner, which could add various functionality.
G200 was Matrox's first fully AGP-compliant graphics processor. While the earlier Millennium II had been adapte
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https://en.wikipedia.org/wiki/Verhoeff%20algorithm
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The Verhoeff algorithm is a checksum for error detection first published by Dutch mathematician Jacobus Verhoeff in 1969. It was the first decimal check digit algorithm which detects all single-digit errors, and all transposition errors involving two adjacent digits, which was at the time thought impossible with such a code.
The method was independently discovered by H. Peter Gumm in 1985, this time including a formal proof and an extension to any base.
Goals
Verhoeff had the goal of finding a decimal code—one where the check digit is a single decimal digit—which detected all single-digit errors and all transpositions of adjacent digits. At the time, supposed proofs of the nonexistence of these codes made base-11 codes popular, for example in the ISBN check digit.
His goals were also practical, and he based the evaluation of different codes on live data from the Dutch postal system, using a weighted points system for different kinds of error. The analysis broke the errors down into a number of categories: first, by how many digits are in error; for those with two digits in error, there are transpositions (ab → ba), twins (aa → 'bb'), jump transpositions (abc → cba), phonetic (1a → a0), and jump twins (aba → cbc). Additionally there are omitted and added digits. Although the frequencies of some of these kinds of errors might be small, some codes might be immune to them in addition to the primary goals of detecting all singles and transpositions.
The phonetic errors in particular showed linguistic effects, because in Dutch, numbers are typically read in pairs; and also while 50 sounds similar to 15 in Dutch, 80 doesn't sound like 18.
Taking six-digit numbers as an example, Verhoeff reported the following classification of the errors:.
Description
The general idea of the algorithm is to represent each of the digits (0 through 9) as elements of the dihedral group . That is, map digits to , manipulate these, then map back into digits. Let this mapping be
Let
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https://en.wikipedia.org/wiki/Freivalds%27%20algorithm
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Freivalds' algorithm (named after Rūsiņš Mārtiņš Freivalds) is a probabilistic randomized algorithm used to verify matrix multiplication. Given three n × n matrices , , and , a general problem is to verify whether . A naïve algorithm would compute the product explicitly and compare term by term whether this product equals . However, the best known matrix multiplication algorithm runs in time. Freivalds' algorithm utilizes randomization in order to reduce this time bound to
with high probability. In time the algorithm can verify a matrix product with probability of failure less than .
The algorithm
Input
Three n × n matrices , , and .
Output
Yes, if ; No, otherwise.
Procedure
Generate an n × 1 random 0/1 vector .
Compute .
Output "Yes" if ; "No," otherwise.
Error
If , then the algorithm always returns "Yes". If , then the probability that the algorithm returns "Yes" is less than or equal to one half. This is called one-sided error.
By iterating the algorithm k times and returning "Yes" only if all iterations yield "Yes", a runtime of and error probability of is achieved.
Example
Suppose one wished to determine whether:
A random two-element vector with entries equal to 0 or 1 is selected say and used to compute:
This yields the zero vector, suggesting the possibility that AB = C. However, if in a second trial the vector is selected, the result becomes:
The result is nonzero, proving that in fact AB ≠ C.
There are four two-element 0/1 vectors, and half of them give the zero vector in this case ( and ), so the chance of randomly selecting these in two trials (and falsely concluding that AB=C) is 1/22 or 1/4. In the general case, the proportion of r yielding the zero vector may be less than 1/2, and a larger number of trials (such as 20) would be used, rendering the probability of error very small.
Error analysis
Let p equal the probability of error. We claim that if A × B = C, then p = 0, and if A × B ≠ C, then p ≤ 1/2.
Case A × B = C
This is re
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https://en.wikipedia.org/wiki/Superconductor%E2%80%93insulator%20transition
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The superconductor–insulator transition is an example of a quantum phase transition, whereupon tuning some parameter in the Hamiltonian, a dramatic change in the behavior of the electrons occurs. The nature of how this transition occurs is disputed, and many studies seek to understand how the order parameter, , changes. Here is the amplitude of the order parameter, and is the phase. Most theories involve either the destruction of the amplitude of the order parameter - by a reduction in the density of states at the Fermi surface, or by destruction of the phase coherence; which results from the proliferation of vortices.
Destruction of superconductivity
In two dimensions, the subject of superconductivity becomes very interesting because the existence of true long-range order is not possible. In the 1970's, J. Michael Kosterlitz and David J. Thouless (along with Vadim Berezinski) showed that a different kind of long-range order could exist - topological order - which showed power law correlations (meaning that by measuring the two-point correlation function it decays algebraically).
This picture changes if disorder is included. Kosterlitz-Thouless behavior can be obtained, but the fluctuations of the order parameter are greatly enhanced, and the transition temperature is suppressed.
The model to keep in mind in the understanding of how superconductivity occurs in a two-dimensional disordered superconductor is the following. At high temperatures, the system is in the normal state. As the system is cooled towards its transition temperature, superconducting grains begin to fluctuate in and out of existence. When one of these grains "pops" into existence, it is accelerated without dissipation for a time before decaying back into the normal state. This has the effect of increasing the conductivity even before the system has condensed into the superconducting state. This increased conductivity above is referred to as paraconductivity, or fluctuation conductivity, and
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https://en.wikipedia.org/wiki/Fumonisin%20B2
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Fumonisin B2 is a fumonisin mycotoxin produced by the fungi Fusarium verticillioides (formerly Fusarium moniliforme) and Aspergillus niger.
It is a structural analog of fumonisin B3, while it is lacking one hydroxy group compared to fumonisin B1.
Fumonisin B2 is more cytotoxic than fumonisin B1. Fumonisin B2 inhibits sphingosine acyltransferase.
Fumonisin B2 and other fumonisins frequently contaminate maize and other crops, while recently it has been shown using LC–MS/MS that FB2 can contaminate coffee beans as well.
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https://en.wikipedia.org/wiki/Nigericin
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Nigericin is an antibiotic derived from Streptomyces hygroscopicus. Its isolation was described in the 1950s, and in 1968 the structure could be elucidated by X-ray crystallography. The structure and properties of nigericin are similar to the antibiotic monensin. Commercially it is obtained as a byproduct, or contaminant, at the fermentation of Geldanamycin. It is also called Polyetherin A, Azalomycin M, Helixin C, Antibiotic K178, Antibiotic X-464.
Nigericin acts as an H+, K+, Pb2+ ionophore. Most commonly it is an antiporter of H+ and K+.
In the past nigericin was used as an antibiotic active against gram positive bacteria. It inhibits the Golgi functions in Eukaryotic cells. Its ability to induce K+ efflux also makes it a potent activator of the NLRP3 inflammasome
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https://en.wikipedia.org/wiki/Electromagnetic%20mass
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Electromagnetic mass was initially a concept of classical mechanics, denoting as to how much the electromagnetic field, or the self-energy, is contributing to the mass of charged particles. It was first derived by J. J. Thomson in 1881 and was for some time also considered as a dynamical explanation of inertial mass per se. Today, the relation of mass, momentum, velocity, and all forms of energy – including electromagnetic energy – is analyzed on the basis of Albert Einstein's special relativity and mass–energy equivalence. As to the cause of mass of elementary particles, the Higgs mechanism in the framework of the relativistic Standard Model is currently used. However, some problems concerning the electromagnetic mass and self-energy of charged particles are still studied.
Charged particles
Rest mass and energy
It was recognized by J. J. Thomson in 1881 that a charged sphere moving in a space filled with a medium of a specific inductive capacity (the electromagnetic aether of James Clerk Maxwell), is harder to set in motion than an uncharged body. (Similar considerations were already made by George Gabriel Stokes (1843) with respect to hydrodynamics, who showed that the inertia of a body moving in an incompressible perfect fluid is increased.) So due to this self-induction effect, electrostatic energy behaves as having some sort of momentum and "apparent" electromagnetic mass, which can increase the ordinary mechanical mass of the bodies, or in more modern terms, the increase should arise from their electromagnetic self-energy. This idea was worked out in more detail by Oliver Heaviside (1889), Thomson (1893), George Frederick Charles Searle (1897), Max Abraham (1902), Hendrik Lorentz (1892, 1904), and was directly applied to the electron by using the Abraham–Lorentz force. Now, the electrostatic energy and mass of an electron at rest was calculated to be
where is the charge, uniformly distributed on the surface of a sphere, and is the classical electron r
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https://en.wikipedia.org/wiki/Timeline%20of%20fundamental%20physics%20discoveries
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This timeline lists significant discoveries in physics and the laws of nature, including experimental discoveries, theoretical proposals that were confirmed experimentally, and theories that have significantly influenced current thinking in modern physics. Such discoveries are often a multi-step, multi-person process. Multiple discovery sometimes occurs when multiple research groups discover the same phenomenon at about the same time, and scientific priority is often disputed. The listings below include some of the most significant people and ideas by date of publication or experiment.
Antiquity
6th century BCE - Ionian school of Greek philosophers: Inception of cosmology and natural philosophy
610-546 BCE - Anaximander: Concept of Earth floating in space
585 BCE - Thales of Miletus: Solar eclipse predicted
460-370 BCE - Democritus: Atomism via thought experiment
384-322 BCE - Aristotle: Aristotelian physics, earliest effective theory of physics
367-282 BCE - Ptolemy: Ptolemaic geocentric system, a phenomenological model of the solar system
300 BCE - Euclid: Euclidean geometry
250 BCE - Archimedes: Archimedes' principle
310-230 BCE - Aristarchos of Samos proposes a Heliocentric model
276-194 BCE - Eratosthenes: Circumference of the Earth measured
190-150 BCE - Seleucus of Seleucia: Support of Heliocentrism based on reasoning
220-150 BCE - Apollonius of Perga and Hipparchus: Invention of Astrolabe
205-86 BCE - Hipparchus or unknown: Antikythera mechanism an analog computer of planetary motions
129 BCE - Hipparchus: Hipparchus star catalog of the entire sky and precession of the equinoxes
Middle Ages
500 CE - John Philoponus: Theory of impetus
984 CE - Ibn Sahl: Law of refraction
1010 - Ibn al-Haytham (Alhazen): Optics, finite speed of light
ca 1030 - Ibn Sina (Avicenna): Concept of force
ca 1050 - al-Biruni: Speed of light is much larger than speed of sound
ca 1100 - Al-Baghdadi: Theory of motion with distinction between velocity and accelerat
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https://en.wikipedia.org/wiki/Unix%20domain%20socket
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A Unix domain socket aka UDS or IPC socket (inter-process communication socket) is a data communications endpoint for exchanging data between processes executing on the same host operating system. It is also referred to by its address family AF_UNIX. Valid socket types in the UNIX domain are:
SOCK_STREAM (compare to TCP) – for a stream-oriented socket
SOCK_DGRAM (compare to UDP) – for a datagram-oriented socket that preserves message boundaries (as on most UNIX implementations, UNIX domain datagram sockets are always reliable and don't reorder datagrams)
SOCK_SEQPACKET (compare to SCTP) – for a sequenced-packet socket that is connection-oriented, preserves message boundaries, and delivers messages in the order that they were sent
The Unix domain socket facility is a standard component of POSIX operating systems.
The API for Unix domain sockets is similar to that of an Internet socket, but rather than using an underlying network protocol, all communication occurs entirely within the operating system kernel. Unix domain sockets may use the file system as their address name space. (Some operating systems, like Linux, offer additional namespaces.) Processes reference Unix domain sockets as file system inodes, so two processes can communicate by opening the same socket.
In addition to sending data, processes may send file descriptors across a Unix domain socket connection using the sendmsg() and recvmsg() system calls. This allows the sending processes to grant the receiving process access to a file descriptor for which the receiving process otherwise does not have access. This can be used to implement a rudimentary form of capability-based security.
See also
Network socket
Berkeley sockets
Pipeline
Netlink
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https://en.wikipedia.org/wiki/Gauge%20factor
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Gauge factor (GF) or strain factor of a strain gauge is the ratio of relative change in electrical resistance R, to the mechanical strain ε. The gauge factor is defined as:
where
ε = strain =
= absolute change in length
= original length
ν = Poisson's ratio
ρ = resistivity
ΔR = change in strain gauge resistance due axial strain and lateral strain
R = unstrained resistance of strain gauge
Piezoresistive effect
It is a common misconception that the change in resistance of a strain gauge is based solely, or most heavily, on the geometric terms. This is true for some materials (), and the gauge factor is simply:
However, most commercial strain gauges utilise resistors made from materials that demonstrate a strong piezoresistive effect. The resistivity of these materials changes with strain, accounting for the term of the defining equation above. In constantan strain gauges (the most commercially popular), the effect accounts for 20% of the gauge factor, but in silicon gauges, the contribution of the piezoresistive term is much larger than the geometric terms. This can be seen in the general examples of strain gauges below:
Effect of temperature
The definition of the gauge factor does not rely on temperature, however the gauge factor only relates resistance to strain if there are no temperature effects. In practice, where changes in temperature or temperature gradients exist, the equation to derive resistance will have a temperature term. The total effect is:
where
α = temperature coefficient
θ = temperature change
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https://en.wikipedia.org/wiki/Vitelline%20circulation
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Vitelline circulation refers to the system of blood flowing from the embryo to the yolk sac and back again.
The yolk-sac is situated on the ventral aspect of the embryo; it is lined by endoderm, outside of which is a layer of mesoderm. It is filled with fluid, the vitelline fluid, which is utilized for the nourishment of the embryo during the earlier stages of its existence. Blood is conveyed to the wall of the sac by the vitelline arteries (a branch of the dorsal aorta), and after circulating through a wide-meshed capillary plexus, is returned by the vitelline veins to the tubular heart of the embryo. This constitutes the vitelline circulation, and by means of it nutritive material is absorbed from the yolk-sac and conveyed to the embryo.
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https://en.wikipedia.org/wiki/Anterior%20cardinal%20vein
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The anterior cardinal veins (precardinal veins) contribute to the formation of the internal jugular veins and together with the common cardinal vein form the superior vena cava.
The anastomosis between the two anterior cardinal veins develops into the left brachiocephalic vein.
Additional images
See also
Posterior cardinal vein
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https://en.wikipedia.org/wiki/Common%20cardinal%20veins
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The common cardinal veins, also known as the ducts of Cuvier, are veins that drain into the sinus venosus during embryonic development. These drain an anterior cardinal vein and a posterior cardinal vein on each side. Each of the ducts of Cuvier receives an ascending vein. The ascending veins return the blood from the parietes of the trunk and from the Wolffian bodies, and are called cardinal veins. Part of the left common cardinal vein persists after birth to form the coronary sinus.
Additional images
See also
Georges Cuvier
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https://en.wikipedia.org/wiki/Ashman%20phenomenon
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Ashman phenomenon, also known as Ashman beats, describes a particular type of wide QRS complex, often seen isolated that is typically seen in atrial fibrillation. It is more often misinterpreted as a premature ventricular complex.
It is named for Richard Ashman (of New Orleans) (1890 –1969), after first being described by Gouaux and Ashman in 1947.
Presentation
Ashman beats are described as wide complex QRS complexes that follow a short R-R interval preceded by a long R-R interval. This short QRS complex typically has a right bundle branch block morphology and represents an aberrantly conducted complex that originates above the AV node, rather than a complex that originates in either the right or left ventricle.
Cause
It occurs because the duration of the refractory period of the myocardium is proportional to the R-R interval of the preceding cycle. A short R-R interval is associated with a shorter duration of action potential and vice versa. A long R-R cycle will prolong the ensuing refractory period, and if a shorter cycle follows, the beat terminating the cycle is likely to be conducted aberrantly. Because the refractory period of the right bundle branch is longer than the left, the right bundle will still be in the refractory period when the supraventricular impulse reaches the His-Purkinje system, resulting in a complex with right bundle branch block morphology.
Prognosis
Clinically, it is often asymptomatic by itself and considered benign in nature.
See also
Atrial fibrillation
Electrocardiogram
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https://en.wikipedia.org/wiki/Oblique%20vein%20of%20the%20left%20atrium
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The oblique vein of the left atrium (oblique vein of Marshall) is a small vein which descends obliquely on the back of the left atrium and ends in the coronary sinus near its left extremity; it is continuous above with the ligament of the left vena cava (vestigial fold of Marshall), and the two structures form the remnant of the left Cuvierian duct. This obscure region of cardiac perfusion adjacent to the SA node rocks back and forth under systole and diastole thus further influencing cardiac autonomic innervation. Ablation of this channel seems reasonable to many observers.
Additional images
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https://en.wikipedia.org/wiki/Posterior%20vein%20of%20the%20left%20ventricle
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The posterior vein of the left ventricle runs on the diaphragmatic surface of the left ventricle to the coronary sinus, but may end in the great cardiac vein.
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https://en.wikipedia.org/wiki/Valve%20of%20coronary%20sinus
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In the anatomy of the heart, the valve of the coronary sinus (also called the Thebesian valve, after Adam Christian Thebesius) is a valve located at the orifice of the coronary sinus where the coronary sinus drains into the right atrium. It prevents blood from flowing backwards into the coronary sinus during contraction of the heart.
Anatomy
The valve of the coronary sinus is a thin, semilunar (half-moon-shaped) valve located on the anteroinferior part of the opening into the right atrium. It is formed by as semicircular fold of the lining membrane of the right atrium. It is situated at the base of the inferior vena cava.
Variation
The valve may be completely absent; it is present in 73-86% of individuals.
The valve may vary in size. It may be double, or it may be cribriform (containing numerous small holes).
Function
The valve prevents regurgitation of blood into the sinus during diastole (i.e. the contraction of the atrium).
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https://en.wikipedia.org/wiki/Hyperboloid%20model
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In geometry, the hyperboloid model, also known as the Minkowski model after Hermann Minkowski, is a model of n-dimensional hyperbolic geometry in which points are represented by points on the forward sheet S+ of a two-sheeted hyperboloid in (n+1)-dimensional Minkowski space or by the displacement vectors from the origin to those points, and m-planes are represented by the intersections of (m+1)-planes passing through the origin in Minkowski space with S+ or by wedge products of m vectors. Hyperbolic space is embedded isometrically in Minkowski space; that is, the hyperbolic distance function is inherited from Minkowski space, analogous to the way spherical distance is inherited from Euclidean distance when the n-sphere is embedded in (n+1)-dimensional Euclidean space.
Other models of hyperbolic space can be thought of as map projections of S+: the Beltrami–Klein model is the projection of S+ through the origin onto a plane perpendicular to a vector from the origin to specific point in S+ analogous to the gnomonic projection of the sphere; the Poincaré disk model is a projection of S+ through a point on the other sheet S− onto perpendicular plane, analogous to the stereographic projection of the sphere; the Gans model is the orthogonal projection of S+ onto a plane perpendicular to a specific point in S+, analogous to the orthographic projection; the band model of the hyperbolic plane is a conformal “cylindrical” projection analogous to the Mercator projection of the sphere; Lobachevsky coordinates are a cylindrical projection analogous to the equirectangular projection (longitude, latitude) of the sphere.
Minkowski quadratic form
If (x0, x1, ..., xn) is a vector in the -dimensional coordinate space Rn+1, the Minkowski quadratic form is defined to be
The vectors such that form an n-dimensional hyperboloid S consisting of two connected components, or sheets: the forward, or future, sheet S+, where x0>0 and the backward, or past, sheet S−, where x0<0. The point
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https://en.wikipedia.org/wiki/Alar%20plate
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The alar plate (or alar lamina) is a neural structure in the embryonic nervous system, part of the dorsal side of the neural tube, that involves the communication of general somatic and general visceral sensory impulses. The caudal part later becomes the sensory axon part of the spinal cord.
The alar plate specifically later on becomes the dorsal gray of the spinal cord, and also develops into the sensory nuclei of cranial nerves V, VII, VIII, IX, and X. The inferior olivary nucleus, mesencephalic nucleus of V, and main sensory nucleus of V are also developed from this plate. The cerebellum also develops from the alar plate, particularly from the rhombic lip. This is considered an exception to the general differentiation scheme from the alar plate, as the alar plate generally gives rise to sensory derivatives.
See also
Basal plate
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https://en.wikipedia.org/wiki/Inner%20cell%20mass
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The inner cell mass (ICM) or embryoblast (known as the pluriblast in marsupials) is a structure in the early development of an embryo. It is the mass of cells inside the blastocyst that will eventually give rise to the definitive structures of the fetus. The inner cell mass forms in the earliest stages of embryonic development, before implantation into the endometrium of the uterus. The ICM is entirely surrounded by the single layer of trophoblast cells of the trophectoderm.
Further development
The physical and functional separation of the inner cell mass from the trophectoderm (TE) is a special feature of mammalian development and is the first cell lineage specification in these embryos. Following fertilization in the oviduct, the mammalian embryo undergoes a relatively slow round of cleavages to produce an eight-cell morula. Each cell of the morula, called a blastomere, increases surface contact with its neighbors in a process called compaction. This results in a polarization of the cells within the morula, and further cleavage yields a blastocyst of roughly 32 cells. In mice, about 12 internal cells comprise the new inner cell mass and 20 – 24 cells comprise the surrounding trophectoderm. There is variation between species of mammals as to the number of cells at compaction with bovine embryos showing differences related to compaction as early as 9-15 cells and in rabbits not until after 32 cells. There is also interspecies variation in gene expression patterns in early embryos.
The ICM and the TE will generate distinctly different cell types as implantation starts and embryogenesis continues. Trophectoderm cells form extraembryonic tissues, which act in a supporting role for the embryo proper. Furthermore, these cells pump fluid into the interior of the blastocyst, causing the formation of a polarized blastocyst with the ICM attached to the trophectoderm at one end (see figure). This difference in cellular localization causes the ICM cells exposed to the fl
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https://en.wikipedia.org/wiki/Coronary%20sulcus
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The coronary sulcus (also called coronary groove, auriculoventricular groove, atrioventricular groove, AV groove) is a groove on the surface of the heart at the base of right auricle that separates the atria from the ventricles. The structure contains the trunks of the nutrient vessels of the heart, and is deficient in front, where it is crossed by the root of the pulmonary trunk. On the posterior surface of the heart, the coronary sulcus contains the coronary sinus. The right coronary artery, circumflex branch of left coronary artery, and small cardiac vein all travel along parts of the coronary sulcus.
Structure
In relation to the rib cage, the coronary sulcus spans from the medial side of the 3rd left costal cartilage, to the middle of the right 6th costal cartilage. Epicardial fat tends to be concentrated along the coronary sulcus.
There are two coronary sulci in the heart, including left and right coronary sulci.
Left coronary sulcus
The left coronary sulcus originates posterior to the pulmonary trunk, and travels inferiorly separating the left atrium and left ventricle. The location of the left coronary sulcus is marked by the circumflex branch of left coronary artery, and coronary sinus.
Right coronary sulcus
The right coronary sulcus begins anteriorly and superiorly on the sternocostal surface of the heart. Its position is marked by the location of the right coronary artery, and small cardiac vein. The right coronary sulcus separates the right atrium and its atrial appendage from the right ventricle inferiorly. The right coronary sulcus then passes inferiorly onto the diaphragmatic surface of the heart and traverses to the left.
Clinical significance
The left coronary sulcus is often neglected in echocardiography. As a result, normal variations and rare pathologic findings can be missed.
See also
Posterior interventricular sulcus
Anterior interventricular sulcus
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https://en.wikipedia.org/wiki/Mathematical%20sociology
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Mathematical sociology or the sociology of mathematics is an interdisciplinary field of research concerned both with the use of mathematics within sociological research as well as research into the relationships that exist between maths and society.
Because of this, mathematical sociology can have a diverse meaning depending on the authors in question and the kind of research being carried out. This creates contestation over whether mathematical sociology is a derivative of sociology, an intersection of the two disciplines, or a discipline in its own right. This is a dynamic, ongoing academic development that leaves mathematical sociology sometimes blurred and lacking in uniformity, presenting grey areas and need for further research into developing its academic merit.
History
Starting in the early 1940s, Nicolas Rashevsky, and subsequently in the late 1940s, Anatol Rapoport and others, developed a relational and probabilistic approach to the characterization of large social networks in which the nodes are persons and the links are acquaintanceship. During the late 1940s, formulas were derived that connected local parameters such as closure of contacts – if A is linked to both B and C, then there is a greater than chance probability that B and C are linked to each other – to the global network property of connectivity.
Moreover, acquaintanceship is a positive tie, but what about negative ties such as animosity among persons? To tackle this problem, graph theory, which is the mathematical study of abstract representations of networks of points and lines, can be extended to include these two types of links and thereby to create models that represent both positive and negative sentiment relations, which are represented as signed graphs. A signed graph is called balanced if the product of the signs of all relations in every cycle (links in every graph cycle) is positive. Through formalization by mathematician Frank Harary, this work produced the fundamental theore
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https://en.wikipedia.org/wiki/Interatrial%20sulcus
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The interatrial sulcus, separating the two atria, is scarcely marked on the posterior surface, while anteriorly it is hidden by the pulmonary artery and aorta.
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https://en.wikipedia.org/wiki/Fold%20of%20left%20vena%20cava
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The fold of the left vena cava, ligament of the left vena cava, or vestigial fold of Marshall, is a triangular fold of the serous pericardium that lies between the left pulmonary artery and subjacent pulmonary vein.
It is formed by the folding of the serous layer over the remnant of the lower part of the left superior vena cava (duct of Cuvier), which becomes obliterated during fetal life, and remains as a fibrous band stretching from the highest left intercostal vein to the left atrium, where it is continuous with a small cardiac vein, the vein of the left atrium (oblique vein of Marshall), which opens into the coronary sinus.
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https://en.wikipedia.org/wiki/Model%20transformation%20language
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A model transformation language in systems and software engineering is a language intended specifically for model transformation.
Overview
The notion of model transformation is central to model-driven development. A model transformation, which is essentially a program which operates on models, can be written in a general-purpose programming language, such as Java. However, special-purpose model transformation languages can offer advantages, such as syntax that makes it easy to refer to model elements. For writing bidirectional model transformations, which maintain consistency between two or more models, a specialist bidirectional model transformation language is particularly important, because it can help avoid the duplication that would result from writing each direction of the transformation separately.
Currently, most model transformation languages are being developed in academia. The OMG has standardised a family of model transformation languages called QVT, but the field is still immature.
There are ongoing debates regarding the benefits of specialised model transformation languages, compared to the use of general-purpose programming languages (GPLs) such as Java. While GPLs have advantages in terms of more widely-available practitioner knowledge and tool support, the specialised transformation languages do provide more declarative facilities and more powerful specialised features to support model transformations.
Available transformation languages
ATL : a transformation language developed by the INRIA
Beanbag (see ) : an operation-based language for establishing consistency over data incrementally
GReAT : a transformation language available in the GME
Epsilon family (see ) : a model management platform that provides transformation languages for model-to-model, model-to-text, update-in-place, migration and model merging transformations.
F-Alloy : a DSL reusing part of the Alloy syntax and allowing the concise specification of efficiently computable m
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https://en.wikipedia.org/wiki/Industrial-grade%20prime
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Industrial-grade primes (the term is apparently due to Henri Cohen) are integers for which primality has not been certified (i.e. rigorously proven), but they have undergone probable prime tests such as the Miller–Rabin primality test, which has a positive, but negligible, failure rate, or the Baillie–PSW primality test, which no composites are known to pass.
Industrial-grade primes are sometimes used instead of certified primes in algorithms such as RSA encryption, which require the user to generate large prime numbers. Certifying the primality of large numbers (over 100 digits for instance) is significantly harder than showing they are industrial-grade primes. The latter can be done almost instantly with a failure rate so low that it is highly unlikely to ever fail in practice. In other words, the number is believed to be prime with very high, but not absolute, confidence.
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https://en.wikipedia.org/wiki/Food%2C%20Beverages%20and%20Catering%20Union
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The Food, Beverages and Catering Union (, NGG) is a trade union in Germany. It has a membership of 205,900 and is one of eight industrial affiliates of the German Confederation of Trade Unions.
Membership
Today, NGG mainly represents employees at major companies such as McDonald's, Nestlé and Unilever in Germany.
Presidents
1949: Gustav Pufal
1950: Ferdinand Warnecke
1951: Hans Nätscher
1962: Alfred Schattanik
1966: Herbert Stadelmaier
1978: Günter Döding
1989: Erich Herrmann
1990: Heinz-Günter Niebrügge
1992: Franz-Josef Möllenberg
2013: Michaela Rosenberger
2018: Guido Zeitler
Notable members
Olaf Scholz – First Mayor of Hamburg
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https://en.wikipedia.org/wiki/Product-family%20engineering
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Product-family engineering (PFE), also known as product-line engineering, is based on the ideas of "domain engineering" created by the Software Engineering Institute, a term coined by James Neighbors in his 1980 dissertation at University of California, Irvine. Software product lines are quite common in our daily lives, but before a product family can be successfully established, an extensive process has to be followed. This process is known as product-family engineering.
Product-family engineering can be defined as a method that creates an underlying architecture of an organization's product platform. It provides an architecture that is based on commonality as well as planned variabilities. The various product variants can be derived from the basic product family, which creates the opportunity to reuse and differentiate on products in the family. Product-family engineering is conceptually similar to the widespread use of vehicle platforms in the automotive industry.
Product-family engineering is a relatively new approach to the creation of new products. It focuses on the process of engineering new products in such a way that it is possible to reuse product components and apply variability with decreased costs and time. Product-family engineering is all about reusing components and structures as much as possible.
Several studies have proven that using a product-family engineering approach for product development can have several benefits. Here is a list of some of them:
Higher productivity
Higher quality
Faster time-to-market
Lower labor needs
The Nokia case mentioned below also illustrates these benefits.
Overall process
The product family engineering process consists of several phases. The three main phases are:
Phase 1: Product management
Phase 2: Domain engineering
Phase 3: Product engineering
The process has been modeled on a higher abstraction level. This has the advantage that it can be applied to all kinds of product lines and families, not on
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https://en.wikipedia.org/wiki/Uncus
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The uncus is an anterior extremity of the parahippocampal gyrus. It is separated from the apex of the temporal lobe by a slight fissure called the incisura temporalis (also called rhinal sulcus).
Although superficially continuous with the hippocampal gyrus, the uncus forms morphologically a part of the rhinencephalon.
An important landmark that crosses the inferior surface of the uncus is the band of Giacomini.
The term comes from the Latin word uncus, meaning hook, and it was coined by Félix Vicq-d'Azyr (1748–1794).
Clinical significance
The part of the olfactory cortex that is on the temporal lobe covers the area of the uncus, which leads into the two significant clinical aspects of the uncus: uncinate fits and uncal herniations.
Seizures, often preceded by hallucinations of disagreeable odors, often originate in the uncus.
In situations of tumor, hemorrhage, or edema, increased pressure within the cranial cavity, especially if the mass is in the middle fossa, can push the uncus over the tentorial notch against the brainstem and its corresponding cranial nerves and can result in a brain herniation. If the uncus becomes herniated the structure lying just medial to it, cranial nerve III, can become compressed. This causes problems associated with a non-functional or problematic CN III - the pupil on the ipsilateral side fails to constrict to light and absence of medial/superior movement of the orbit, resulting in a fixed, dilated pupil and an eye with a characteristic "down and out" position due to dominance of the abducens and trochlear nerves. Further pressure on the midbrain results in progressive lethargy, coma and death due to compression of the mesencephalic reticular activating system. Brainstem damage is typically ipsilateral to the herniation, although the contralateral cerebral peduncle may be pushed against the tentorial notch, resulting in a characteristic indentation known as Kernohan's notch and ipsilateral hemiparesis, since fibers running in
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https://en.wikipedia.org/wiki/Chyron%20Corporation
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The Chyron Corporation, formerly ChyronHego Corporation, headquartered in Melville, New York, is a company that specializes in broadcast graphics creation, playout, and real-time data visualization for live television, news, weather, and sports production. Chyron's graphics offerings include hosted services for graphics creation and order management, on-air graphics systems, channel branding, weather graphics, graphics asset management, clip servers, social media and second screen applications, touchscreen graphics, telestration, virtual graphics, and player tracking.
The company was founded in 1966 as Systems Resources Corporation. In its early days it was renamed "Chiron" after the centaur Chiron in Greek mythology. In the 1970s it pioneered the development of broadcast titling and graphics systems. Use of its graphics generators by the major New York City–based US television networks ABC, NBC, and eventually CBS, integrated text and graphics into news and sports coverage on broadcast television and later on cable TV.
By the 1980s, Chyron had captured a 70% market share in its field. In it was the most profitable company on Long Island. In 1983 it achieved a market capitalization of $112 million, high at the time for a small high-tech firm before the age of dot-com and the Internet.
Corporate history
Chyron's graphics generator technology was originated by Systems Resources Corporation, founded in 1966 by Francis Mechner and engineer Eugene Leonard as equal partners and sole directors and shareholders. Mechner had just sold his educational technology company Basic Systems, Inc. to Xerox Corporation; and Leonard had sold Digitronics Corporation, of which he was president. Mechner and Leonard previously worked together in the late 1950s at Schering Corporation, creating a computerized data collection and analysis system for its behavioral psychopharmacology laboratory.
Mechner provided the capital for Systems Resources Corporation's first five years of operatio
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https://en.wikipedia.org/wiki/BioSteel%20%28fiber%29
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BioSteel was a trademark name for a high-strength fiber-based material made of the recombinant spider silk-like protein extracted from the milk of transgenic goats, made by defunct Montreal-based company Nexia Biotechnologies, and later by the Randy Lewis lab of the University of Wyoming and Utah State University. It is reportedly 7-10 times as strong as steel if compared for the same weight, and can stretch up to 20 times its unaltered size without losing its strength properties. It also has very high resistance to extreme temperatures, not losing any of its properties within .
The company had created lines of goats to produce recombinant versions of two spidroins from Nephila clavipes, the golden orb weaver, MaSp1 and MaSp2 When the female goats lactate, the milk, containing the recombinant DNA silk, was to be harvested and subjected to chromatographic techniques to purify the recombinant silk proteins.
The purified silk proteins could be dried, dissolved using solvents (DOPE formation) and transformed into microfibers using wet-spinning fiber production methods. The spun fibers were reported to have tenacities in the range of 2 - 3 grams/denier and elongation range of 25-45%. The "Biosteel biopolymer" had been transformed into nanofibers and nanomeshes using the electrospinning technique.
Nexia is the only company that has successfully produced fibers from spider silk expressed in goat's milk. The Lewis lab has produced fibers from recombinant spider silk protein and synthetic spider silk proteins and genetic chimeras produced in both recombinant E. coli and the milk of recombinant goats, however, no one has been able to produce the silk in commercial quantities thus far. The company was founded in 1993 by Dr. Jeffrey Turner and Paul Ballard and was sold in 2005 to Pharmathene.
In 2009, two transgenic goats were sold to the Canada Agriculture Museum after Nexia Biotechnologies went bankrupt.
Research has since continued with the help of Randy Lewis, a profes
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https://en.wikipedia.org/wiki/Szekeres%20snark
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In the mathematical field of graph theory, the Szekeres snark is a snark with 50 vertices and 75 edges. It was the fifth known snark, discovered by George Szekeres in 1973.
As a snark, the Szekeres graph is a connected, bridgeless cubic graph with chromatic index equal to 4. The Szekeres snark is non-planar and non-hamiltonian but is hypohamiltonian. It has book thickness 3 and queue number 2.
Another well known snark on 50 vertices is the Watkins snark discovered by John J. Watkins in 1989.
Gallery
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https://en.wikipedia.org/wiki/Gemfire
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Gemfire (released in Japan as Royal Blood or ロイヤルブラッド Roiyaru Buraddo, Super Royal Blood or スーパーロイヤルブラッド Sūpā Roiyaru Buraddo in its Super Famicom version) is a medieval war game for MSX, Nintendo Entertainment System, Super NES, FM Towns, Mega Drive/Genesis, DOS, and later Microsoft Windows, developed by Koei. The object in the game is to unify a fictional island by force. Players use infantry, cavalry, and archers, as well as fantasy units such as magicians, dragons or gargoyles in order to capture the castle needed to control that particular territory.
A sequel, Royal Blood II, was released in the Japan market for Windows.
Plot
The game takes place in the fictitious Isle of Ishmeria. Once upon a time, six wizards, each wielding a unique brand of magic, used their powers to protect the island and maintain peace. This was disrupted when they were collectively challenged by a Fire Dragon, summoned forth by a wizard intent on plunging the country into darkness.
The sea-dwelling dragon of peace known as the Pastha charged the six wizards with the task of fighting back. They succeeded, sealing the Fire Dragon away into a ruby at the top of a crown, and themselves became the six jewels around the crown's base. The crown, called Gemfire, was a symbol of utmost power and authority.
When Gemfire fell into the hands of the now current King of Ishmeria, Eselred, he sought to abuse the object's power, using it to embark on a tyrannical reign, instilling fear within his oppressed subjects. Ishmeria fell into despair as his power flourished. Finally, his young daughter, Princess Robyn, could not bear to watch her father's grievous misdeeds any longer — she seized Gemfire and pried the six wizard gems loose, causing them to shoot upward into the sky and circle briefly overhead before scattering themselves to different parts of Ishmeria. When a furious Eselred learned of Robyn's actions, he had her locked her away in a tower; but it was futile as the deed had already been do
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https://en.wikipedia.org/wiki/History%20of%20wound%20care
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The history of wound care spans from prehistory to modern medicine. Wounds naturally heal by themselves, but hunter-gatherers would have noticed several factors and certain herbal remedies would speed up or assist the process, especially if it was grievous. In ancient history, this was followed by the realisation of the necessity of hygiene and the halting of bleeding, where wound dressing techniques and surgery developed. Eventually the germ theory of disease also assisted in improving wound care.
Ancient medical practice
Over time, different civilizations began to create their own herbal medicinal treatments for wounds depending on the trees, shrubs, or any other type of plants located in their environment. These herbal treatments became the oldest form of wound therapy. It is logically assumed that this may not have been a very safe way of treating humans with wounds due to overdosing or choosing the wrong plants to treat a person until the right one was found. Nevertheless, most of the ancient people who were given the duty of healers through the usage of herbs were well accustomed with which plants from their local flora could be used to help the injured. This knowledge was learned and passed down after healers repeatedly used an herbal remedy for a specific wound with the belief that it promoted healing.
Numerous ancient herbal remedies and poisons now serve as models for modern medicine. For example, curare, which was an ancient South American arrow poison, was used in the 20th century as the muscle relaxant tubocurarine. Tribesmen conducted various observations on the effects of different plant parts, meaning roots, leaves, etc., on specific wounds. They also observed what seasons, time of day, or moon phase would result in a most active plant. The former however resulted in a minimal influence in modern medicine as compared to plants parts or seasons of growth.
Ancient Greece
As tribal healers developed into doctors, it spurred on a primitive pharmace
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https://en.wikipedia.org/wiki/Elementary%20number
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An elementary number is one formalization of the concept of a closed-form number. The elementary numbers form an algebraically closed field containing the roots of arbitrary expressions using field operations, exponentiation, and logarithms. The set of the elementary numbers is subdivided into the explicit elementary numbers and the implicit elementary numbers.
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https://en.wikipedia.org/wiki/List%20of%20platform-independent%20GUI%20libraries
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This is a list of notable library packages implementing a graphical user interface (GUI) platform-independent GUI library (PIGUI). These can be used to develop software that can be ported to multiple computing platforms with no change to its source code.
In C, C++
In other languages
No longer available or supported
See also
List of widget toolkits
List of rich web application frameworks
Further reading
Richard Chimera, Evaluation of Platform Independent User Interface Builders, March 1993, Human-Computer Interaction Laboratory University of Maryland
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https://en.wikipedia.org/wiki/Mental%20chronometry
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Mental chronometry is the scientific study of processing speed or reaction time on cognitive tasks to infer the content, duration, and temporal sequencing of mental operations. Reaction time (RT; sometimes incorrectly referred to as "response time") is measured by the elapsed time between stimulus onset and an individual's response on elementary cognitive tasks (ECTs), which are relatively simple perceptual-motor tasks typically administered in a laboratory setting. Mental chronometry is one of the core methodological paradigms of human experimental, cognitive, and differential psychology, but is also commonly analyzed in psychophysiology, cognitive neuroscience, and behavioral neuroscience to help elucidate the biological mechanisms underlying perception, attention, and decision-making in humans and other species.
Mental chronometry uses measurements of elapsed time between sensory stimulus onsets and subsequent behavioral responses to study the time course of information processing in the nervous system. Distributional characteristics of response times such as means and variance are considered useful indices of processing speed and efficiency, indicating how fast an individual can execute task-relevant mental operations. Behavioral responses are typically button presses, but eye movements, vocal responses, and other observable behaviors are often used. Reaction time is thought to be constrained by the speed of signal transmission in white matter as well as the processing efficiency of neocortical gray matter.
The use of mental chronometry in psychological research is far ranging, encompassing nomothetic models of information processing in the human auditory and visual systems, as well as differential psychology topics such as the role of individual differences in RT in human cognitive ability, aging, and a variety of clinical and psychiatric outcomes. The experimental approach to mental chronometry includes topics such as the empirical study of vocal and manual
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https://en.wikipedia.org/wiki/Gunfire%20locator
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A gunfire locator or gunshot detection system is a system that detects and conveys the location of gunfire or other weapon fire using acoustic, vibration, optical, or potentially other types of sensors, as well as a combination of such sensors. These systems are used by law enforcement, security, military, government offices, schools and businesses to identify the source and, in some cases, the direction of gunfire and/or the type of weapon fired. Most systems possess three main components:
An array of microphones or sensors (accelerometers, infrared detectors, etc) either co-located or geographically dispersed
A processing unit
A user-interface that displays gunfire alerts
In general categories, there are environmental packaged systems for primarily outdoor use (both military and civilian/urban) which are high cost and then also lower cost consumer/industrial packaged systems for primarily indoor use. Systems used in urban settings integrate a geographic information system so the display includes a map and address location of each incident. Some indoor gunfire detection systems utilize detailed floor plans with detector location overlay to show shooter locations on an app or web based interface.
History
Determination of the origin of gunfire by sound was conceived before World War I where it was first used operationally (see: Artillery sound ranging).
In 1990, a unique algorithm was used as a starting point : Metravib defence, working with Délégation Générale pour l’Armement (DGA) – the French defence procurement agency – studied the acoustic signature of submarines. The DGA & Section Technique de l’Armée de Terre (STAT), the French Army’s engineering section
subsequently commissioned Metravib D. to find a solution for shot detection, a way to assist soldiers and peacekeepers who come under fire from snipers without knowing precisely where the shots were coming from.
In the early 1990s, the areas of East Palo Alto and eastern Menlo Park, California, were
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https://en.wikipedia.org/wiki/Morra%20%28game%29
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Morra is a hand game that dates back thousands of years to ancient Roman and Greek times. Each player simultaneously reveals their hand, extending any number of fingers, and calls out a number. Any player who successfully guesses the total number of fingers revealed by all players combined scores a point.
Morra can be played to decide issues, much as two people might toss a coin, or for entertainment.
Rules
While there are many variations of morra, most forms can be played with a minimum of two players. In the most popular version, all players throw out a single hand, each showing zero to five fingers, and call out their guess at what the sum of all fingers shown will be. If one player guesses the sum, that player earns one point. The first player to reach three points wins the game.
Some variants of morra involve money, with the winner earning an amount equal to the sum of fingers displayed.
History
Morra was known to the ancient Romans and is popular around the world, especially in Italy. In ancient Rome, it was called micatio, and playing it was referred to as micare digitis; literally, "to flash with the fingers". As time passed, the name became morra, a corruption of the verb micare. The game was so common in ancient Rome that there was a proverb used to denote an honest person which made reference to it: dignus est quicum in tenebris mices, literally, "he is a worthy man with whom you could play micatio in the dark". Micatio became so common that it came to be used to settle disputes over the sale of merchandise in the Roman forum. This practice was eventually banned by Apronius, prefect of the city. The game followed Roman colonists as they spread through Europe, the Near East and North Africa. The game is also mentioned by Aristotle, but it seems that it has not been very common in Greece.
Today, morra can be found throughout Italy (notably in Sardinia, where it is called ), Greece, the Province of Teruel in Spain, Corsica, France, Portugal, Cyprus,
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https://en.wikipedia.org/wiki/Overline
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An overline, overscore, or overbar, is a typographical feature of a horizontal line drawn immediately above the text. In old mathematical notation, an overline was called a vinculum, a notation for grouping symbols which is expressed in modern notation by parentheses, though it persists for symbols under a radical sign. The original use in Ancient Greek was to indicate compositions of Greek letters as Greek numerals. In Latin, it indicates Roman numerals multiplied by a thousand and it forms medieval abbreviations (sigla). Marking one or more words with a continuous line above the characters is sometimes called overstriking, though overstriking generally refers to printing one character on top of an already-printed character.
An overline, that is, a single line above a chunk of text, should not be confused with the macron, a diacritical mark placed above (or sometimes below) individual letters. The macron is narrower than the character box.
Uses
Medicine
In most forms of Latin scribal abbreviation, an overline or macron indicates omitted letters similar to use of apostrophes in English contractions. Letters with macrons or overlines continue to be used in medical abbreviations in various European languages, particularly for prescriptions. Common examples include
, a̅, or ā for ("before")
, c̅, or c̄ for ("with")
, p̅, or p̄ for ("after")
, q̅, or q̄ for and its inflections ("every", "each")
, s̅, or s̄ for ("without")
, x̅, or x̄ for and its inflections ("except")
Note, however, that abbreviations involving the letter h take their macron halfway up the ascending line rather than at the normal height for Unicode overlines and macrons: ħ. This is separately encoded in Unicode with the symbols using bar diacritics and appears shorter than other overlines in many fonts.
Math and science
Decimal separator
In the Middle Ages, from the original Indian decimal writing, before printing, an overline over the units digit was used to separate the integral p
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https://en.wikipedia.org/wiki/Data%20integration
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Data integration involves combining data residing in different sources and providing users with a unified view of them. This process becomes significant in a variety of situations, which include both commercial (such as when two similar companies need to merge their databases) and scientific (combining research results from different bioinformatics repositories, for example) domains. Data integration appears with increasing frequency as the volume (that is, big data) and the need to share existing data explodes. It has become the focus of extensive theoretical work, and numerous open problems remain unsolved. Data integration encourages collaboration between internal as well as external users. The data being integrated must be received from a heterogeneous database system and transformed to a single coherent data store that provides synchronous data across a network of files for clients. A common use of data integration is in data mining when analyzing and extracting information from existing databases that can be useful for Business information.
History
Issues with combining heterogeneous data sources are often referred to as information silos, under a single query interface have existed for some time. In the early 1980s, computer scientists began designing systems for interoperability of heterogeneous databases. The first data integration system driven by structured metadata was designed at the University of Minnesota in 1991, for the Integrated Public Use Microdata Series (IPUMS). IPUMS used a data warehousing approach, which extracts, transforms, and loads data from heterogeneous sources into a unique view schema so data from different sources become compatible. By making thousands of population databases interoperable, IPUMS demonstrated the feasibility of large-scale data integration. The data warehouse approach offers a tightly coupled architecture because the data are already physically reconciled in a single queryable repository, so it usually takes lit
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https://en.wikipedia.org/wiki/Computer%20Automated%20Measurement%20and%20Control
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Computer-Aided Measurement And Control (CAMAC) is a standard bus and modular-crate electronics standard for data acquisition and control used in particle detectors for nuclear and particle physics and in industry. The bus allows data exchange between plug-in modules (up to 24 in a single crate) and a crate controller, which then interfaces to a PC or to a VME-CAMAC interface.
The standard was originally defined by the ESONE Committee as standard EUR 4100 in 1972, and covers the mechanical, electrical, and logical elements of a parallel bus ("dataway") for the plug-in modules. Several standards have been defined for multiple crate systems, including the Parallel Branch Highway definition and Serial Highway definition. Vendor-specific Host/Crate interfaces have also been built.
The CAMAC standard encompasses IEEE standards:
583 The base standard
683 Block transfer specifications (Q-stop and Q-scan)
596 Parallel Branch Highway systems
595 Serial highway system
726 Real-time Basic for CAMAC
675 Auxiliary crate controller specification/support
758 FORTRAN subroutines for CAMAC.
Within the , modules are addressed by slot (geographical addressing). The left-most 22 slots are available for application modules while the right-most two slots are dedicated to a crate controller. Within a slot the standard defines 16 subaddresses (0–15). A slot commanded by the controller with one of 32 function codes (0–31). Of these function codes, 0–7 are read functions and will transfer data to the controller from the addressed module, while 16–23 are write function codes which will transfer data from the controller to the module.
In addition to functions that address the module, the following global functions are defined:
I – Crate inhibit
Z – Crate zero
C – Crate clear
The original standard was capable of one 24-bit data transfer every microsecond. Later a revision to the standard was released to support short cycles which allow a transfer every 450 ns. A follow on
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https://en.wikipedia.org/wiki/Metanephrogenic%20blastema
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The metanephrogenic blastema or metanephric blastema (or metanephric mesenchyme, or metanephric mesoderm) is one of the two embryological structures that give rise to the kidney, the other being the ureteric bud.
The metanephric blastema mostly develops into nephrons, but can also form parts of the collecting duct system.
The system of tissue induction between the ureteric bud and the metanephric blastema is a reciprocal control system. GDNF, glial cell-derived neurotrophic factor, is produced by the metanephric blastema and is essential in binding to the Ret receptor on the ureteric bud, which bifurcates and coalesces as a result to form the renal pelvis, major and minor calyces and collecting ducts. Mutations in the EYA1 gene, whose product regulates GDNF expression in the developing kidney, lead to the renal abnormalities of BOR syndrome (branchio-oto-renal syndrome).
See also
Mesenchyme
Metanephros
Blastema
Kidney development
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https://en.wikipedia.org/wiki/Regina%20%28program%29
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Regina is a suite of mathematical software for 3-manifold topologists. It focuses upon the study of 3-manifold triangulations and includes support for normal surfaces and angle structures.
Features
Regina implements a variant of Rubinstein's 3-sphere recognition algorithm. This is an algorithm that determines whether or not a triangulated 3-manifold is homeomorphic to the 3-sphere.
Regina further implements the connect-sum decomposition. This will decompose a triangulated 3-manifold into a connect-sum of triangulated prime 3-manifolds.
Homology and Poincare duality for 3-manifolds, including the torsion linking form.
Includes portions of the SnapPea kernel for some geometric calculations.
Has both a GUI and Python interface.
See also
Computational topology
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https://en.wikipedia.org/wiki/Enthalpy%20of%20sublimation
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In thermodynamics, the enthalpy of sublimation, or heat of sublimation, is the heat required to sublimate (change from solid to gas) one mole of a substance at a given combination of temperature and pressure, usually standard temperature and pressure (STP). It is equal to the cohesive energy of the solid. For elemental metals, it is also equal to the standard enthalpy of formation of the gaseous metal atoms. The heat of sublimation is usually expressed in kJ/mol, although the less customary kJ/kg is also encountered.
Sublimation enthalpies
See also
Heat
Sublimation (chemistry)
Phase transition
Clausius-Clapeyron equation
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https://en.wikipedia.org/wiki/Haynes%E2%80%93Shockley%20experiment
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In semiconductor physics, the Haynes–Shockley experiment was an experiment that demonstrated that diffusion of minority carriers in a semiconductor could result in a current. The experiment was reported in a short paper by Haynes and Shockley in 1948, with a more detailed version published by Shockley, Pearson, and Haynes in 1949.
The experiment can be used to measure carrier mobility, carrier lifetime, and diffusion coefficient.
In the experiment, a piece of semiconductor gets a pulse of holes, for example, as induced by voltage or a short laser pulse.
Equations
To see the effect, we consider a n-type semiconductor with the length d. We are interested in determining the mobility of the carriers, diffusion constant and relaxation time. In the following, we reduce the problem to one dimension.
The equations for electron and hole currents are:
where the js are the current densities of electrons (e) and holes (p), the μs the charge carrier mobilities, E is the electric field, n and p the number densities of charge carriers, the Ds are diffusion coefficients, and x is position. The first term of the equations is the drift current, and the second term is the diffusion current.
Derivation
We consider the continuity equation:
Subscript 0s indicate equilibrium concentrations. The electrons and the holes recombine with the carrier lifetime τ.
We define
so the upper equations can be rewritten as:
In a simple approximation, we can consider the electric field to be constant between the left and right electrodes and neglect ∂E/∂x. However, as electrons and holes diffuse at different speeds, the material has a local electric charge, inducing an inhomogeneous electric field which can be calculated with Gauss's law:
where ε is permittivity, ε0 the permittivity of free space, ρ is charge density, and e0 elementary charge.
Next, change variables by the substitutions:
and suppose δ to be much smaller than . The two initial equations write:
Using the Einstein rel
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https://en.wikipedia.org/wiki/Lateral%20plate%20mesoderm
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The lateral plate mesoderm is the mesoderm that is found at the periphery of the embryo. It is to the side of the paraxial mesoderm, and further to the axial mesoderm. The lateral plate mesoderm is separated from the paraxial mesoderm by a narrow region of intermediate mesoderm. The mesoderm is the middle layer of the three germ layers, between the outer ectoderm and inner endoderm.
During the third week of embryonic development the lateral plate mesoderm splits into two layers forming the intraembryonic coelom.
The outer layer of lateral plate mesoderm adheres to the ectoderm to become the somatic or parietal layer known as the somatopleure. The inner layer adheres to the endoderm to become the splanchnic or visceral layer known as the splanchnopleure.
Development
The lateral plate mesoderm will split into two layers, the somatopleuric mesenchyme, and the splanchnopleuric mesenchyme.
The somatopleuric layer forms the future body wall.
The splanchnopleuric layer forms the circulatory system.
Spaces within the lateral plate are enclosed and forms the intraembryonic coelom.
It is formed by the secretion of BMP-4 by the ectoderm.
Serosal mesoderms
Lateral plate mesoderm gives rise to the serosal mesoderms.
forms a ventral layer associated with endoderm, the splanchnopleuric mesoderm. This forms the viscera and heart
forms a dorsal layer associated with ectoderm, the somatopleuric mesoderm. This forms the body wall lining and dermis.
Abdominal portion becomes contained in dorsal mesentery, part of the serosal mesoderm.
When the two layers form, a cardiogenic plate is visible. Later, this will form the myocardial primordium, which will contribute to the tubular heart.
Cavities
In the 4th week the coelom divides into pericardial, pleural and peritoneal cavities.
First partition: is the septum transversum.
This will be translocated later into the diaphragm and ventral mesentery.
Divides the coelom into primitive pericardial and peritoneal cavities
Pleuroperic
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https://en.wikipedia.org/wiki/Paraxial%20mesoderm
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Paraxial mesoderm, also known as presomitic or somitic mesoderm, is the area of mesoderm in the neurulating embryo that flanks and forms simultaneously with the neural tube. The cells of this region give rise to somites, blocks of tissue running along both sides of the neural tube, which form muscle and the tissues of the back, including connective tissue and the dermis.
Formation and somitogenesis
The paraxial and other regions of the mesoderm are thought to be specified by bone morphogenetic proteins (BMPs) along an axis spanning from the center to the sides of the body. Members of the fibroblast growth factor family also play an important role, as does the Wnt pathway. In particular, Noggin, a downstream target of the Wnt pathway, antagonizes BMP signaling, forming boundaries where antagonists meet and limiting this signaling to a particular region of the mesoderm. Together, these pathways provide the initial specification of the paraxial mesoderm and maintain this identity.
This specification process has now been fully recapitulated in vitro with the formation of paraxial mesoderm progenitors from pluripotent stem cells, using a directed differentiation approach.
The tissue undergoes convergent extension as the primitive streak regresses, or as the embryo gastrulates. The notochord extends from the base of the head to the tail; with it extend thick bands of paraxial mesoderm.
As the primitive streak continues to regress, somites form from the paraxial mesoderm by "budding off" rostrally.
In certain model systems, it has been shown that the daughter cells of stem cell-like progenitor cells which come from the primitive streak or site of gastrulation migrate out and localize in the posterior paraxial mesoderm. As the primitive streak regresses and somites bud off anteriorly, new cells derived from these stem-cell like precursors constantly enter the posterior end of the paraxial mesoderm.
Derived tissues
Many kinds of tissue derive from the segmented paraxi
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https://en.wikipedia.org/wiki/Axial%20mesoderm
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Axial mesoderm, or chordamesoderm, is the mesoderm in the embryo that lies along the central axis under the neural tube.
will give rise to notochord
starts as the notochordal process, whose formation finishes at day 20 in humans.
important not only in forming the notochord itself but also in inducing development of the overlying ectoderm into the neural tube
will eventually induce the formation of vertebral bodies.
ventral floor of the notochordal process fuses with endoderm.
The notochord will form the nucleus pulposus of intervertebral discs. There is some discussion as to whether these cells contributed from the notochord are replaced by others from the adjacent mesoderm.
It gives rise to the notochordal process, which later becomes the notochord.
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https://en.wikipedia.org/wiki/Steven%20Strogatz
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Steven Henry Strogatz (), born August 13, 1959, is an American mathematician and the Susan and Barton Winokur Distinguished Professor for the Public Understanding of Science and Mathematics at Cornell University.
He is known for his work on nonlinear systems, including contributions to the study of synchronization in dynamical systems, and for his research in a variety of areas of applied mathematics, including mathematical biology and complex network theory.
Strogatz is the host of Quanta Magazine'''s The Joy of Why podcast. He previously hosted The Joy of x podcast, named after his book of the same name.
Education
Strogatz attended high school at Loomis Chaffee from 1972 to 1976. He then attended Princeton University, graduating summa cum laude with a B.A. in mathematics. Strogatz completed his senior thesis, titled "The mathematics of supercoiled DNA: an essay in geometric biology", under the supervision of Frederick J. Almgren, Jr. Strogatz then studied as a Marshall Scholar at Trinity College, Cambridge, from 1980 to 1982, and then received a Ph.D. in applied mathematics from Harvard University in 1986 for his research on the dynamics of the human sleep-wake cycle. He completed his postdoc under Nancy Kopell at Boston University.
Career
After spending three years as a National Science Foundation Postdoctoral Fellow at Harvard and Boston University, Strogatz joined the faculty of the department of mathematics at MIT in 1989. His research on dynamical systems was recognized with a Presidential Young Investigator Award from the National Science Foundation in 1990. In 1994 he moved to Cornell where he is a professor of mathematics. From 2007 to 2023 he was the Jacob Gould Schurman Professor of Applied Mathematics, and in 2023 he was named the inaugural holder of the Susan and Barton Winokur Distinguished Professorship for the Public Understanding of Science and Mathematics. From 2004 to 2010, he was also on the external faculty of the Santa Fe Institute.
Rese
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https://en.wikipedia.org/wiki/Stomodeum
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The stomodeum, also called stomatodeum or stomatodaeum, is a depression between the brain and the pericardium in an embryo, and is the precursor to the mouth and the anterior lobe of the pituitary gland.
Development
The mouth is developed partly from the stomodeum, and partly from the floor of the anterior portion of the fore-gut.
By the growth of the head end of the embryo, and the formation of the cephalic flexure, the pericardial area and the buccopharyngeal membrane come to lie on the ventral surface of the embryo.
With the further expansion of the brain, and the forward bulging of the pericardium, the buccopharyngeal membrane is depressed between these two prominences. This depression constitutes the stomodeum.
No trace of the membrane is found in the adult; and the communication just mentioned must not be confused with the permanent isthmus faucium.
The lips, teeth, and gums are formed from the walls of the stomodeum, but the tongue is developed in the floor of the pharynx.
History
It is from the Greek stoma- (mouth) and odaios (likeness), "which looks like a mouth".
Additional images
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https://en.wikipedia.org/wiki/Anterior%20triangle%20of%20the%20neck
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The anterior triangle is a region of the neck.
Structure
The triangle is inverted with its apex inferior to its base which is under the chin.
Investing fascia covers the roof of the triangle while visceral fascia covers the floor.
Anatomy
Muscles:
Suprahyoid muscles - Digastric (Ant and Post Belly), mylohyoid, geniohyoid and Stylohyoid.
Infrahyoid muscles - Omohyoid, Sternohyoid, Sternothyroid, and Thyrohyoid.
Nerve supply
2 Bellies of Digastric
Anterior: Mylohyoid nerve
Posterior: Facial nerve
Stylohyoid: by the facial nerve, by a branch from that to the posterior belly of digastric.
Mylohyoid: by its own nerve, a branch of the inferior alveolar ( from the mandibular division of trigeminal nerve), which arises just before the parent nerve enters the mandibular foramen, pierces the sphenomandibular ligament, and runs forward on the inferior surface of the mylohyoid, supplying it and the anterior belly of the digastric.
Geniohyoid: by a branch from the hypoglossal nerve consisting of fibres from the C1 nerve.
Sternohyoid, Omohyoid, Sternothyroid are supplied by Ansa cervicalis.
Thyrohyoid: by a branch of hypoglossal nerve but the fibres are all 'hitch-hiking' from C1.
Development
Anterior: 1st Pharyngeal arch
Posterior: 2nd Pharyngeal arch
Divisions
This space is subdivided into four smaller triangles by the Digastricus above, and the superior belly of the Omohyoideus.
These smaller triangles are named:
the muscular triangle
the carotid triangle
the submandibular triangle
the submental triangle
Additional images
See also
Posterior triangle of the neck
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https://en.wikipedia.org/wiki/Deep%20cervical%20fascia
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The deep cervical fascia (or fascia colli in older texts) lies under cover of the platysma, and invests the muscles of the neck; it also forms sheaths for the carotid vessels, and for the structures situated in front of the vertebral column. Its attachment to the hyoid bone prevents the formation of a dewlap.
The investing portion of the fascia is attached behind to the ligamentum nuchæ and to the spinous process of the seventh cervical vertebra.
The alar fascia is a portion of the deep cervical fascia.
Divisions
The deep cervical fascia is often divided into a superficial, middle, and deep layer.
The superficial layer is also known as the investing layer of deep cervical fascia. It envelops the trapezius, sternocleidomastoid, and muscles of facial expression. It also contains the submandibular and parotid salivary gland as well as the muscles of mastication (the masseter, pterygoid, and temporalis muscles).
The middle layer is also known as the pretracheal fascia. It envelopes the strap muscles (sternohyoid, sternothyroid, thyrohyoid, and omohyoid muscles). It also surrounds the pharynx, larynx, trachea, esophagus, thyroid, parathyroids, buccinators, and constrictor muscles of the pharynx.
The deep layer is also known as the prevertebral fascia. It surrounds the paraspinous muscles and cervical vertebrae.
The carotid sheath is also considered a component of the deep cervical fascia.
Superior extent of the investing fascia
Above, the fascia is attached to the superior nuchal line of the occipital bone, to the mastoid process of the temporal bone, and to the whole length of the inferior border of the body of the mandible.
Opposite the angle of the mandible the fascia is very strong, and binds the anterior edge of the sternocleidomastoideus firmly to that bone.
Between the mandible and the mastoid process it ensheathes the parotid gland—the layer which covers the gland extends upward under the name of the parotideomasseteric fascia and is fixed to the zygoma
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https://en.wikipedia.org/wiki/Axillary%20sheath
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The axillary sheath is a fibrous sheath that encloses the axillary artery and the three cords of the brachial plexus to form the neurovascular bundle. It is surrounded by the axillary fat. It is an extension of the prevertebral fascia of the deep cervical fascia and is continuous with the carotid sheath at the venous angle.
A brachial plexus nerve block can be achieved by injecting anaesthetic into this area.
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https://en.wikipedia.org/wiki/Enolase%20superfamily
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The enolase superfamily is a superfamily of enzymes, members of which catalyse a range of reactions.
The enolase superfamily includes enzymes that catalyse a wide variety of reactions and performing diverse roles in metabolism. However, the reactions catalysed share the common chemical step of abstraction of a proton from a carbon adjacent to a carboxylic acid and a requirement of a divalent metal ion. This diversity of functions is in contrast to many families of enzymes whose members catalyse similar chemical reactions on different substrates.
Members
Enolase
Mandelate racemase (MR)
Muconate lactonizing enzyme (MLE)
The primary sequences of MR and MLE, approximately 25% identical, are related but significantly different; whereas their three-dimensional structures are similar. The enzyme enolase has a more distant, but nevertheless clear, relationship to MLE and MR. The enolase superfamily has served as a model superfamily for understanding enzyme function and is one of the protein families under study by the Enzyme Function Initiative (EFI).
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https://en.wikipedia.org/wiki/Representation%20theorem
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In mathematics, a representation theorem is a theorem that states that every abstract structure with certain properties is isomorphic to another (abstract or concrete) structure.
Examples
Algebra
Cayley's theorem states that every group is isomorphic to a permutation group.
Representation theory studies properties of abstract groups via their representations as linear transformations of vector spaces.
Stone's representation theorem for Boolean algebras states that every Boolean algebra is isomorphic to a field of sets.
A variant, Stone's representation theorem for distributive lattices, states that every distributive lattice is isomorphic to a sublattice of the power set lattice of some set.
Another variant, Stone's duality, states that there exists a duality (in the sense of an arrow-reversing equivalence) between the categories of Boolean algebras and that of Stone spaces.
The Poincaré–Birkhoff–Witt theorem states that every Lie algebra embeds into the commutator Lie algebra of its universal enveloping algebra.
Ado's theorem states that every finite-dimensional Lie algebra over a field of characteristic zero embeds into the Lie algebra of endomorphisms of some finite-dimensional vector space.
Birkhoff's HSP theorem states that every model of an algebra A is the homomorphic image of a subalgebra of a direct product of copies of A.
In the study of semigroups, the Wagner–Preston theorem provides a representation of an inverse semigroup S, as a homomorphic image of the set of partial bijections on S, and the semigroup operation given by composition.
Category theory
The Yoneda lemma provides a full and faithful limit-preserving embedding of any category into a category of presheaves.
Mitchell's embedding theorem for abelian categories realises every small abelian category as a full (and exactly embedded) subcategory of a category of modules over some ring.
Mostowski's collapsing theorem states that every well-founded extensional structure is isomorphic t
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https://en.wikipedia.org/wiki/Babassu%20oil
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Babassu oil or cusi oil is a clear light yellow vegetable oil extracted from the seeds of the babassu palm (Attalea speciosa) which grows in the Amazon region of South America. It is a non-drying oil used in food, cleaners and skin products. This oil has properties similar to coconut oil and is used in much the same context. It is increasingly being used as a substitute for coconut oil. Babassu oil is about 70% lipids, in the following proportions:
Lauric and myristic acids have melting points relatively close to human body temperature, so babassu oil can be applied to the skin as a solid that melts on contact. This heat transfer can produce a cooling sensation. It is an effective emollient.
During February 2008, a mixture of babassu oil and coconut oil was used to partially power one engine of a Boeing 747, in a biofuel trial sponsored by Virgin Atlantic.
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https://en.wikipedia.org/wiki/Circumflex%20branch%20of%20left%20coronary%20artery
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The circumflex branch of left coronary artery (also known as the left circumflex artery, or circumflex artery) is a branch of the left coronary artery. It winds around the left side of the heart along the atrioventricular groove (coronary sulcus). It supplies the posterolateral portion of the left ventricle.
In a minority of individuals, the left circumflex artery gives rise to the posterior interventricular artery, in which cases such a heart is deemed left dominant.
Anatomy
The left circumflex artery follows the left part of the coronary sulcus, running first to the left and then to the right, reaching nearly as far as the posterior longitudinal sulcus. There have been multiple anomalies described, for example the left circumflex having an aberrant course from the right coronary artery.
Branches
The circumflex artery curves to the left around the heart within the coronary sulcus, giving rise to one or more left marginal arteries (also called obtuse marginal branches) as it curves toward the posterior surface of the heart. It helps form the posterior left ventricular branch or posterolateral artery. The circumflex artery ends at the point where it joins to form to the posterior interventricular artery in 15% of all cases, which lies in the posterior interventricular sulcus. In the other 85% of all cases the posterior interventricular artery comes out of the right coronary artery. When the left circumflex supplies the posterior descending artery in those 15% of cases, it is known as a left dominant circulation.
Distribution
The circumflex artery supplies the posterolateral left ventricle and the anterolateral papillary muscle.
It also supplies the sinoatrial nodal artery in 38% of people.
It supplies 15–25% of the left ventricle in right-dominant systems. If the coronary anatomy is left-dominant, the circumflex artery supplies 40–50% of the left ventricle.
Additional images
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https://en.wikipedia.org/wiki/Vaginal%20branches%20of%20uterine%20artery
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The uterine artery supplies branches to the cervix uteri and others which descend on the vagina; the latter anastomose with branches of the vaginal arteries and form with them two median longitudinal vessels—the vaginal branches of uterine artery (or azygos arteries of the vagina)—one of which runs down in front of and the other behind the vagina.
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https://en.wikipedia.org/wiki/Short%20ciliary%20nerves
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The short ciliary nerves are nerves of the orbit around the eye. They are branches of the ciliary ganglion. They supply parasympathetic and sympathetic nerve fibers to the ciliary muscle, iris, and cornea. Damage to the short ciliary nerve may result in loss of the pupillary light reflex, or mydriasis.
Structure
The short ciliary nerves are branches of the ciliary ganglion. They arise from the forepart of the ganglion in two bundles connected with its superior and inferior angles. The lower bundle is the larger than the upper bundle. These split into between 6 and 10 filaments.
They run forward with the ciliary arteries in a wavy course. One bundle is set above the optic nerve, while the other bundle is set below it. They are accompanied by the long ciliary nerves from the nasociliary.
They pierce the sclera at the back part of the bulb of the eye, pass forward in delicate grooves on the inner surface of the sclera, and are distributed to the ciliary muscle, iris, and cornea.
Function
The short ciliary nerves contain both parasympathetic and sympathetic nerve fibers. The parasympathetic fibers arise from the Edinger-Westphal nucleus and synapse in the ciliary ganglion via the oculomotor nerve, the postganglionic parasympathetics leave the ciliary ganglion in the short ciliary nerve and supply the ciliary body and iris. The sympathetic fibers are provided by the superior cervical ganglion, and reach the ganglion either as branches of the nasociliary nerve or directly from the extension of the plexus on the ophthalmic artery (sympathetic branch to ciliary ganglion). The sympathetics are non-specific and provide vasoconstriction of the globe.
Clinical significance
Damage to the short ciliary nerve may result in loss of the pupillary light reflex, or mydriasis.
Additional images
See also
Long ciliary nerves
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https://en.wikipedia.org/wiki/Ciliary%20arteries
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The ciliary arteries are divisible into three groups, the long posterior, short posterior, and the anterior.
The short posterior ciliary arteries from six to twelve in number, arise from the ophthalmic artery as it crosses the optic nerve.
The long posterior ciliary arteries, two for each eye, pierce the posterior part of the sclera at some little distance from the optic nerve.
The anterior ciliary arteries are derived from the muscular branches of the ophthalmic artery.
Additional images
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https://en.wikipedia.org/wiki/Bioelectrical%20impedance%20analysis
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Bioelectrical impedance analysis (BIA) is a method for estimating body composition, in particular body fat and muscle mass, where a weak electric current flows through the body and the voltage is measured in order to calculate impedance (resistance and reactance) of the body. Most body water is stored in muscle. Therefore, if a person is more muscular there is a high chance that the person will also have more body water, which leads to lower impedance. Since the advent of the first commercially available devices in the mid-1980s the method has become popular owing to its ease of use and portability of the equipment. It is familiar in the consumer market as a simple instrument for estimating body fat. BIA actually determines the electrical impedance, or opposition to the flow of an electric current through body tissues which can then be used to estimate total body water (TBW), which can be used to estimate fat-free body mass and, by difference with body weight, body fat.
Accuracy
Many of the early research studies showed that BIA was quite variable and it was not regarded by many as providing an accurate measure of body composition. In recent years technological improvements have made BIA much more reliable and therefore more acceptable way of measuring body composition. Nevertheless, it is the 4-compartment model (4C) (DXA and MRI are acceptable alternatives) – and not BIA – that is regarded as the reference method in body composition analysis.
Although the instruments are straightforward to use, careful attention to the method of use (as described by the manufacturer) should be given.
Simple devices to estimate body fat, often using BIA, are available to consumers as body fat meters. These instruments are generally regarded as being less accurate than those used clinically or in nutritional and medical practice. They tend to under-read body fat percentage by approximately 5 kg (±7 kg LoA) on average, despite showing a linear correlation with MRI-based measurem
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https://en.wikipedia.org/wiki/Hole%20punching%20%28networking%29
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Hole punching (or sometimes punch-through) is a technique in computer networking for establishing a direct connection between two parties in which one or both are behind firewalls or behind routers that use network address translation (NAT). To punch a hole, each client connects to an unrestricted third-party server that temporarily stores external and internal address and port information for each client. The server then relays each client's information to the other, and using that information each client tries to establish direct connection; as a result of the connections using valid port numbers, restrictive firewalls or routers accept and forward the incoming packets on each side.
Hole punching does not require any knowledge of the network topology to function. ICMP hole punching, UDP hole punching and TCP hole punching respectively use Internet Control Message, User Datagram and Transmission Control Protocols.
Overview
Networked devices with public or globally accessible IP addresses can create connections between one another easily. Clients with private addresses may also easily connect to public servers, as long as the client behind a router or firewall initiates the connection. However, hole punching (or some other form of NAT traversal) is required to establish a direct connection between two clients that both reside behind different firewalls or routers that use network address translation (NAT).
Both clients initiate a connection to an unrestricted server, which notes endpoint and session information including public IP and port along with private IP and port. The firewalls also note the endpoints in order to allow responses from the server to pass back through. The server then sends each client's endpoint and session information to the other client, or peer. Each client tries to connect to its peer through the specified IP address and port that the peer's firewall has opened for the server. The new connection attempt punches a hole in the client's fir
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https://en.wikipedia.org/wiki/Werner%20Fenchel
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Moritz Werner Fenchel (; 3 May 1905 – 24 January 1988) was a mathematician known for his contributions to geometry and to optimization theory. Fenchel established the basic results of convex analysis and nonlinear optimization theory which would, in time, serve as the foundation for nonlinear programming. A German-born Jew and early refugee from Nazi suppression of intellectuals, Fenchel lived most of his life in Denmark. Fenchel's monographs and lecture notes are considered influential.
Biography
Early life and education
Fenchel was born on 3 May 1905 in Berlin, Germany, his younger brother was the Israeli film director and architect Heinz Fenchel.
Fenchel studied mathematics and physics at the University of Berlin between 1923 and 1928. He wrote his doctorate thesis in geometry (Über Krümmung und Windung geschlossener Raumkurven) under Ludwig Bieberbach.
Professorship in Germany
From 1928 to 1933, Fenchel was Professor E. Landau's Assistant at the University of Göttingen. During a one-year leave (on Rockefeller Fellowship) between 1930 and 1931, Fenchel spent time in Rome with Levi-Civita, as well as in Copenhagen with Harald Bohr and Tommy Bonnesen.
He visited Denmark again in 1932.
Professorship in exile
Fenchel taught at Göttingen until 1933, when the Nazi discrimination laws led to mass-firings of Jews.
Fenchel emigrated to Denmark somewhere between April and September 1933, ultimately obtaining a position at the University of Copenhagen. In December 1933, Fenchel married fellow German refugee mathematician Käte Sperling.
When Germany occupied Denmark, Fenchel and roughly eight-thousand other Danish Jews received refuge in Sweden, where he taught (between 1943 and 1945) at the Danish School in Lund. After the Allied powers' liberation of Denmark, Fenchel returned to Copenhagen.
Professorship postwar
In 1946, Fenchel was elected a member of the Royal Danish Academy of Sciences and Letters.
On leave between 1949 and 1951, Fenchel taught in the U.S
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https://en.wikipedia.org/wiki/Common%20Data%20Representation
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Common Data Representation (CDR) is used to represent structured or primitive data types passed as arguments or results during remote invocations on Common Object Request Broker Architecture (CORBA) distributed objects.
It enables clients and servers written in different programming languages to work together. For example, it translates little-endian to big-endian. It assumes prior agreement on type, so no information is given with data representation in messages.
External links
Official CDR spec (see PDF page 4).
ACE Library provides CDR streams.
Common Object Request Broker Architecture
Data serialization formats
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https://en.wikipedia.org/wiki/Greater%20sciatic%20foramen
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The greater sciatic foramen is an opening (foramen) in the posterior human pelvis. It is formed by the sacrotuberous and sacrospinous ligaments. The piriformis muscle passes through the foramen and occupies most of its volume. The greater sciatic foramen is wider in women than in men.
Structure
It is bounded as follows:
anterolaterally by the greater sciatic notch of the ilium.
posteromedially by the sacrotuberous ligament.
inferiorly by the sacrospinous ligament and the ischial spine.
superiorly by the anterior sacroiliac ligament.
Function
The piriformis, which exits the pelvis through the foramen, occupies most of its volume.
The following structures also exit the pelvis through the greater sciatic foramen:
See also
Lesser sciatic foramen
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https://en.wikipedia.org/wiki/Nick%20DeWolf
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Nicholas DeWolf (July 12, 1928 – April 16, 2006) was co-founder of Teradyne, a Boston, Massachusetts-based manufacturer of automatic test equipment. He founded the company in 1960 with Alex d'Arbeloff, a classmate at MIT.
Early life and education
DeWolf was born in Philadelphia, Pennsylvania and graduated with an S.B. in EECS from MIT in 1948.
Career
During his eleven years as CEO of Teradyne, DeWolf is credited with designing more than 300 semiconductor and other test systems, including the J259, the world's first computer-operated integrated circuit tester.
After leaving Teradyne in 1971, DeWolf moved to Aspen, Colorado, where in 1979, he teamed with artist Travis Fulton to create Aspen's "dancing fountain". DeWolf also designed a computer system without hard disks or fans; this system (the ON! computer) booted up in seconds, a much faster time than even the computers of today.
Awards
1979: Semiconductor Equipment and Materials International SEMI Award for North America.
2001: Telluride Tech Festival Award of Technology, Boulder, CO.
2005: inducted into the Aspen Hall of Fame with wife Maggie DeWolf.
Photography
DeWolf was also a keen and prolific photographer. His son-in-law and archivist, Steve Lundeen, is scanning DeWolf's complete archive and making it available on Flickr.
Death
DeWolf died in Aspen, Colorado at the age of 77.
Quotes
"What the customer demands is last year's model, cheaper. To find out what the customer needs you have to understand what the customer is doing as well as he understands it. Then you build what he needs and you educate him to the fact that he needs it."
"To select a component, size a product, design a system or plan a new company, first test the extremes and then have the courage to resist what is popular and the wisdom to choose what is best".
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https://en.wikipedia.org/wiki/Medial%20plantar%20nerve
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The medial plantar nerve (internal plantar nerve) is the larger of the two terminal divisions of the tibial nerve (medial and lateral plantar nerve), which accompanies the medial plantar artery.
From its origin under the laciniate ligament it passes under cover of the abductor hallucis muscle, and, appearing between this muscle and the flexor digitorum brevis, gives off a proper digital plantar nerve and finally divides opposite the bases of the metatarsal bones into three common digital plantar nerves.
Branches
The branches of the medial plantar nerve are: (1) cutaneous, (2) muscular, (3) articular, (4) a proper digital nerve to the medial side of the great toe, and (5) three common digital nerves.
Cutaneous branches
The cutaneous branches pierce the plantar aponeurosis between the abductor hallucis and the flexor digitorum brevis and are distributed to the skin of the sole of the foot.
Muscular branches
The muscular branches supply muscles on the medial side of the sole, including the abductor hallucis, the flexor digitorum brevis, the flexor hallucis brevis, and the first lumbrical; those for the abductor hallucis and flexor digitorum brevis arise from the trunk of the nerve near its origin and enter the deep surfaces of the muscles; the branch of the flexor hallucis brevis springs from the proper digital nerve to the medial side of the great toe, and that for the first lumbrical is from the first common digital nerve.
Articular branches
The articular branches supply the articulations of the tarsus and metatarsus.
Proper digital nerve of the great toe
The proper digital nerve of the great toe (nn. digitales plantares proprii; plantar digital branches) supplies the flexor hallucis brevis and the skin on the medial side of the great toe.
Three common digital nerves
The three common digital nerves (nn. digitales plantares communes) pass between the divisions of the plantar aponeurosis, and each splits into two proper digital nerves—those of the first common d
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https://en.wikipedia.org/wiki/Semipredicate%20problem
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In computer programming, a semipredicate problem occurs when a subroutine intended to return a useful value can fail, but the signalling of failure uses an otherwise valid return value. The problem is that the caller of the subroutine cannot tell what the result means in this case.
Example
The division operation yields a real number, but fails when the divisor is zero. If we were to write a function that performs division, we might choose to return 0 on this invalid input. However, if the dividend is 0, the result is 0 too. This means there is no number we can return to uniquely signal attempted division by zero, since all real numbers are in the range of division.
Practical implications
Early programmers handled potentially exceptional cases such as division using a convention requiring the calling routine to verify the inputs before calling the division function. This had two problems: first, it greatly encumbered all code that performed division (a very common operation); second, it violated the Don't repeat yourself and encapsulation principles, the former of which suggesting eliminating duplicated code, and the latter suggesting that data-associated code be contained in one place (in this division example, the verification of input was done separately). For a computation more complicated than division, it could be difficult for the caller to recognize invalid input; in some cases, determining input validity may be as costly as performing the entire computation. The target function could also be modified and would then expect different preconditions than would the caller; such a modification would require changes in every place where the function was called.
Solutions
The semipredicate problem is not universal among functions that can fail.
Using a custom convention to interpret return values
If the range of a function does not cover the entire space corresponding to the data type of the function's return value, a value known to be impossible under norm
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https://en.wikipedia.org/wiki/Lateral%20plantar%20nerve
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The lateral plantar nerve (external plantar nerve) is a branch of the tibial nerve, in turn a branch of the sciatic nerve and supplies the skin of the fifth toe and lateral half of the fourth, as well as most of the deep muscles, its distribution being similar to that of the ulnar nerve in the hand.
It passes obliquely forward with the lateral plantar artery to the lateral side of the foot, lying between the flexor digitorum brevis and quadratus plantae and, in the interval between the flexor muscle and the abductor digiti minimi, divides into a superficial and a deep branch. Before its division, it supplies the quadratus plantae and abductor digiti minimi. It divides into deep and superficial branches.
Additional images
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https://en.wikipedia.org/wiki/International%20Centre%20for%20Genetic%20Engineering%20and%20Biotechnology
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The International Centre for Genetic Engineering and Biotechnology (ICGEB) was established as a project of the United Nations Industrial Development Organization (UNIDO) in 1983. The Organisation has three Component laboratories with over 45 ongoing research projects in Infectious and Non-communicable diseases, Medical, Industrial and Plant Biology Biotechnology in: Trieste, Italy, New Delhi, India and Cape Town, South Africa.
On February 3, 1994, under the direction of Arturo Falaschi the ICGEB became an autonomous International Organisation and now has over 65 Member States across world regions.
Its main pillars of action comprise: Research, Advanced Education through PhD and Postdoctoral Fellowships, International Scientific Meetings and Courses, competitive Grants for scientists in Member States and Technology Transfer to industry.
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https://en.wikipedia.org/wiki/Endocardial%20cushions
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Endocardial cushions, or atrioventricular cushions, refer to a subset of cells in the development of the heart that play a vital role in the proper formation of the heart septa.
They develop on the atrioventricular canal and conotruncal region of the bulbus cordis.
During heart development, the heart starts out as a tube. As heart development continues, this tube undergoes remodeling to eventually form the four-chambered heart. The endocardial cushions are a subset of cells found in the developing heart tube that will give rise to the heart's primitive valves and septa, critical to the proper formation of a four-chambered heart.
Development
The endocardial cushions are thought to arise from a subset of endothelial cells that undergo epithelial-mesenchymal transition, a process whereby these cells break cell-to-cell contacts and migrate into the cardiac jelly (towards the interior of the heart tube). These migrated cells form the "swellings" called the endocardial cushions seen in the heart tube.
Upon sectioning of the heart the atrioventricular endocardial cushions can be observed in the lumen of the atrial canal as two thickenings, one on its dorsal and another on its ventral wall. These thickenings will go on to fuse and remodel to eventually form the valves and septa of the mature adult heart.
Clinical significance
A problem in endocardial cushion development or remodeling is thought to be associated with atrioventricular septal defect.
See also
Endocardial tubes
Heart development
Mesenchyme
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https://en.wikipedia.org/wiki/Ogden%20tables
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The Ogden tables are a set of statistical tables and other information for use in court cases in the UK. Their purpose is to make it easier to calculate future losses in personal injury and fatal accident cases.
The tables take into account life expectancy and provide a range of discount rates from -2.0% to 3.0% in steps of 0.5%. The discount rate is fixed by the Lord Chancellor under section 1 of the Damages Act 1996; as of 15 July 2019, this rate is -0.25%. The discount rate in Northern Ireland is -1.5%.
The full and official name of the tables is Actuarial Tables with explanatory notes for use in Personal Injury and Fatal Accident Cases, but the unofficial name became common parlance following the Civil Evidence Act 1995, where this shorthand name was used as a subheading – Sir Michael Ogden QC having been the chairman of the Working Party for the first four editions.
History
The tables were first published in 1984.
Section 10 of the Civil Evidence Act 1995 authorised their use in evidence in the UK "for the purpose of assessing, in an action for personal injury, the sum to be awarded as general damages for future pecuniary loss". They were first used by the House of Lords in Wells v. Wells in July 1999.
The 7th edition of the tables made changes to the discount rate range (previously 0.0% to 5.0% revised to -2.0% to 3.0%) to allow for a revision of the rate by the Lord Chancellor (currently under consideration as at 24 October 2011) and to provide for the implications of the case of Helmot v. Simon. The 8th edition was published in 2020 and updated in August 2022.
Using the Ogden tables
There are 28 tables of data in the Ogden Tables. Table 1 (Males) and Table 2 (Females) are for life expectancy and loss for life. Tables 3 to 14 are for loss of earnings up to various retirement ages. Tables 15 to 26 are for loss of pension from various retirement ages. Table 27 is for discounting for a time in the future and Table 28 is for a recurring loss over a period
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https://en.wikipedia.org/wiki/Septum%20intermedium
|
Endocardial cushions project into the atrial canal, and, meeting in the middle line, unite to form the septum intermedium which divides the canal into two channels, the future right and left atrioventricular orifices.
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https://en.wikipedia.org/wiki/Linear%20dynamical%20system
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Linear dynamical systems are dynamical systems whose evolution functions are linear. While dynamical systems, in general, do not have closed-form solutions, linear dynamical systems can be solved exactly, and they have a rich set of mathematical properties. Linear systems can also be used to understand the qualitative behavior of general dynamical systems, by calculating the equilibrium points of the system and approximating it as a linear system around each such point.
Introduction
In a linear dynamical system, the variation of a state vector
(an -dimensional vector denoted ) equals a constant matrix
(denoted ) multiplied by
. This variation can take two forms: either
as a flow, in which varies
continuously with time
or as a mapping, in which
varies in discrete steps
These equations are linear in the following sense: if
and
are two valid solutions, then so is any linear combination
of the two solutions, e.g.,
where and
are any two scalars. The matrix
need not be symmetric.
Linear dynamical systems can be solved exactly, in contrast to most nonlinear ones. Occasionally, a nonlinear system can be solved exactly by a change of variables to a linear system. Moreover, the solutions of (almost) any nonlinear system can be well-approximated by an equivalent linear system near its fixed points. Hence, understanding linear systems and their solutions is a crucial first step to understanding the more complex nonlinear systems.
Solution of linear dynamical systems
If the initial vector
is aligned with a right eigenvector of
the matrix , the dynamics are simple
where is the corresponding eigenvalue;
the solution of this equation is
as may be confirmed by substitution.
If is diagonalizable, then any vector in an -dimensional space can be represented by a linear combination of the right and left eigenvectors (denoted ) of the matrix .
Therefore, the general solution for is
a linear combination of the individual solutions for the rig
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https://en.wikipedia.org/wiki/Quantum%20Turing%20machine
|
A quantum Turing machine (QTM) or universal quantum computer is an abstract machine used to model the effects of a quantum computer. It provides a simple model that captures all of the power of quantum computation—that is, any quantum algorithm can be expressed formally as a particular quantum Turing machine. However, the computationally equivalent quantum circuit is a more common model.
Quantum Turing machines can be related to classical and probabilistic Turing machines in a framework based on transition matrices. That is, a matrix can be specified whose product with the matrix representing a classical or probabilistic machine provides the quantum probability matrix representing the quantum machine. This was shown by Lance Fortnow.
Informal sketch
A way of understanding the quantum Turing machine (QTM) is that it generalizes the classical Turing machine (TM) in the same way that the quantum finite automaton (QFA) generalizes the deterministic finite automaton (DFA). In essence, the internal states of a classical TM are replaced by pure or mixed states in a Hilbert space; the transition function is replaced by a collection of unitary matrices that map the Hilbert space to itself.
That is, a classical Turing machine is described by a 7-tuple .
For a three-tape quantum Turing machine (one tape holding the input, a second tape holding intermediate calculation results, and a third tape holding output):
The set of states is replaced by a Hilbert space.
The tape alphabet symbols are likewise replaced by a Hilbert space (usually a different Hilbert space than the set of states).
The blank symbol is an element of the Hilbert space.
The input and output symbols are usually taken as a discrete set, as in the classical system; thus, neither the input nor output to a quantum machine need be a quantum system itself.
The transition function is a generalization of a transition monoid and is understood to be a collection of unitary matrices that are automorphism
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https://en.wikipedia.org/wiki/Lattice%20reduction
|
In mathematics, the goal of lattice basis reduction is to find a basis with short, nearly orthogonal vectors when given an integer lattice basis as input. This is realized using different algorithms, whose running time is usually at least exponential in the dimension of the lattice.
Nearly orthogonal
One measure of nearly orthogonal is the orthogonality defect. This compares the product of the lengths of the basis vectors with the volume of the parallelepiped they define. For perfectly orthogonal basis vectors, these quantities would be the same.
Any particular basis of vectors may be represented by a matrix , whose columns are the basis vectors . In the fully dimensional case where the number of basis vectors is equal to the dimension of the space they occupy, this matrix is square, and the volume of the fundamental parallelepiped is simply the absolute value of the determinant of this matrix . If the number of vectors is less than the dimension of the underlying space, then volume is . For a given lattice , this volume is the same (up to sign) for any basis, and hence is referred to as the determinant of the lattice or lattice constant .
The orthogonality defect is the product of the basis vector lengths divided by the parallelepiped volume;
From the geometric definition it may be appreciated that with equality if and only if the basis is orthogonal.
If the lattice reduction problem is defined as finding the basis with the smallest possible defect, then the problem is NP-hard . However, there exist polynomial time algorithms to find a basis with defect
where c is some constant depending only on the number of basis vectors and the dimension of the underlying space (if different). This is a good enough solution in many practical applications.
In two dimensions
For a basis consisting of just two vectors, there is a simple and efficient method of reduction closely analogous to the Euclidean algorithm for the greatest common divisor of two integers. As with
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https://en.wikipedia.org/wiki/Pointwise
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In mathematics, the qualifier pointwise is used to indicate that a certain property is defined by considering each value of some function An important class of pointwise concepts are the pointwise operations, that is, operations defined on functions by applying the operations to function values separately for each point in the domain of definition. Important relations can also be defined pointwise.
Pointwise operations
Formal definition
A binary operation on a set can be lifted pointwise to an operation on the set of all functions from to as follows: Given two functions and , define the function by
Commonly, o and O are denoted by the same symbol. A similar definition is used for unary operations o, and for operations of other arity.
Examples
where .
See also pointwise product, and scalar.
An example of an operation on functions which is not pointwise is convolution.
Properties
Pointwise operations inherit such properties as associativity, commutativity and distributivity from corresponding operations on the codomain.
If is some algebraic structure, the set of all functions to the carrier set of can be turned into an algebraic structure of the same type in an analogous way.
Componentwise operations
Componentwise operations are usually defined on vectors, where vectors are elements of the set for some natural number and some field . If we denote the -th component of any vector as , then componentwise addition is .
Componentwise operations can be defined on matrices. Matrix addition, where is a componentwise operation while matrix multiplication is not.
A tuple can be regarded as a function, and a vector is a tuple. Therefore, any vector corresponds to the function such that , and any componentwise operation on vectors is the pointwise operation on functions corresponding to those vectors.
Pointwise relations
In order theory it is common to define a pointwise partial order on functions. With A, B posets, the set of functions A → B ca
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https://en.wikipedia.org/wiki/Dbx%20Model%20700%20Digital%20Audio%20Processor
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The dbx Model 700 Digital Audio Processor was a professional audio ADC/DAC combination unit, which digitized a stereo analog audio input into a bitstream, which was then encoded and encapsulated in an analog composite video signal, for recording to tape using a VCR as a transport. Unlike other similar pieces of equipment like the Sony PCM-F1, the Model 700 used a technique called Companded Predictive Delta Modulation, rather than the now-common pulse-code modulation. At the time of its introduction in the mid-1980s the device was the first commercial product to use this method, although it had been proposed in the 1960s and prototyped in the late '70s.
History
Unlike the many digital recording formats that would follow (e.g. DAT and ADAT), the Model 700 had no capability for storage on its own, and relied on an analog recording medium supplied by the user. In general, any high-quality VHS VCR would do, although 3/4" U-matic or Beta decks could also have been used. If viewed on a monitor, the output stream of a Model 700 looked like analog TV "static" or noise, with slight black bars running down either side.
Early on, the machine was hailed as "the best recording device you can buy," and Stereophile Magazine reviewed it positively. Many people liked the format because it offered more dynamic range than analog tape, but without the "hard clipping" inherent in PCM audio recorders of the time. The Model 700 had been designed from the beginning to have many 'tape-like' characteristics, including "soft saturation," and at a time when most professional and amateur recordists were used to analog tape, this was considered a significant feature. It also offered 14 dB more dynamic range than 44.1 kHz/16b audio, and because of its very high sample rate (644 kHz), it did not contain the same anti-aliasing filters necessary in PCM recorders at the time, which were thought to cause undesirable harmonic interference.
The device sold for $4,600 in 1986, and that was without a
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https://en.wikipedia.org/wiki/Ischioanal%20fossa
|
The ischioanal fossa (formerly called ischiorectal fossa) is the fat-filled wedge-shaped space located lateral to the anal canal and inferior to the pelvic diaphragm. It is somewhat prismatic in shape, with its base directed to the surface of the perineum and its apex at the line of meeting of the obturator and anal fasciae.
Boundaries
It has the following boundaries:
Contents
The contents include:
Inside Alcock's canal, on the lateral wall
internal pudendal artery
internal pudendal vein
pudendal nerve
Outside Alcock's canal, crossing the space transversely
inferior rectal artery
inferior rectal veins
inferior anal nerves
fatty tissue across which numerous fibrous bands extend from side to side allows distension of the anal canal during defecation
See also
Anal triangle
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https://en.wikipedia.org/wiki/Anal%20fascia
|
The anal fascia is the inferior layer of the diaphragmatic part of the pelvic fascia, which covers both surfaces of the levatores ani. It is attached above to the obturator fascia along the line of origin of the levator ani, while below it is continuous with the superior fascia of the urogenital diaphragm, and with the fascia on the sphincter ani internus.
The layer covering the upper surface of the pelvic diaphragm follows, above, the line of origin of the levator ani and is therefore somewhat variable.
In front it is attached to the back of the pubic symphysis about 2 cm. above its lower border.
It can then be traced laterally across the back of the superior ramus of the pubic bone for a distance of about 1.25 cm, when it reaches the obturator fascia.
It is attached to this fascia along a line which pursues a somewhat irregular course to the spine of the ischium.
The irregularity of this line is because the origin of the levator ani, which in lower forms is from the pelvic brim, is in man lower down, on the obturator fascia.
Tendinous fibers of origin of the muscle are therefore often found extending up toward, and in some cases reaching, the pelvic brim, and on these the fascia is carried.
See also
Inferior fascia of pelvic diaphragm
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https://en.wikipedia.org/wiki/PostBQP
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In computational complexity theory, PostBQP is a complexity class consisting of all of the computational problems solvable in polynomial time on a quantum Turing machine with postselection and bounded error (in the sense that the algorithm is correct at least 2/3 of the time on all inputs).
Postselection is not considered to be a feature that a realistic computer (even a quantum one) would possess, but nevertheless postselecting machines are interesting from a theoretical perspective.
Removing either one of the two main features (quantumness, postselection) from PostBQP gives the following two complexity classes, both of which are subsets of PostBQP:
BQP is the same as PostBQP except without postselection
BPPpath is the same as PostBQP except that instead of quantum, the algorithm is a classical randomized algorithm (with postselection)
The addition of postselection seems to make quantum Turing machines much more powerful: Scott Aaronson proved PostBQP is equal to PP, a class which is believed to be relatively powerful, whereas BQP is not known even to contain the seemingly smaller class NP. Using similar techniques, Aaronson also proved that small changes to the laws of quantum computing would have significant effects. As specific examples, under either of the two following changes, the "new" version of BQP would equal PP:
if we broadened the definition of 'quantum gate' to include not just unitary operations but linear operations, or
if the probability of measuring a basis state was proportional to instead of for any even integer p > 2.
Basic properties
In order to describe some of the properties of PostBQP we fix a formal way of describing quantum postselection. Define a quantum algorithm to be a family of quantum circuits (specifically, a uniform circuit family). We designate one qubit as the postselection qubit P and another as the output qubit Q. Then PostBQP is defined by postselecting upon the event that the postselection qubit is . Explicitly, a
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https://en.wikipedia.org/wiki/Pudendal%20canal
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The pudendal canal (also called Alcock's canal) is an anatomical structure formed by the obturator fascia (fascia of the obturator internus muscle) lining the lateral wall of the ischioanal fossa. The internal pudendal artery and veins, and pudendal nerve pass through the pudendal canal, and the perineal nerve arises within it.
Clinical significance
Pudendal nerve entrapment can occur when the pudendal nerve is compressed while it passes through the pudendal canal.
History
The pudendal canal is also known as Alcock's canal, named after Benjamin Alcock.
Additional images
See also
Femoral canal
Inguinal canal
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https://en.wikipedia.org/wiki/Fascia%20of%20Colles
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The membranous layer of the superficial fascia of the perineum (Colles' fascia) is the deeper layer (membranous layer) of the superficial perineal fascia. It is thin, aponeurotic in structure, and of considerable strength, serving to bind down the muscles of the root of the penis. Colles' fascia emerges from the perineal membrane, which divides the base of the penis from the prostate. Colles' fascia emerges from the inferior side of the perineal membrane and continues along the ventral (inferior) penis without covering the scrotum. It separates the skin and subcutaneous fat from the superficial perineal pouch.
Relations
In front, it is continuous with the dartos fascia of the penis and Scarpa's fascia upon the anterior wall of the abdomen;
On either side it is firmly attached to the margins of the rami of the pubis and ischium, lateral to the crus penis and as far back as the tuberosity of the ischium.
Posteriorly, it curves around the superficial transverse perineal muscle to join the lower margin of the inferior fascia of the urogenital diaphragm.
In the middle line, it is connected with the superficial fascia and with the median septum of the bulbospongiosus muscle.
This fascia not only covers the muscles in this region, but at its back part sends upward a vertical septum from its deep surface, which separates the posterior portion of the subjacent space into two.
Additional images
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https://en.wikipedia.org/wiki/Ischial%20tuberosity
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The ischial tuberosity (or tuberosity of the ischium, tuber ischiadicum), also known colloquially as the sit bones or sitz bones, or as a pair the sitting bones, is a large swelling posteriorly on the superior ramus of the ischium. It marks the lateral boundary of the pelvic outlet.
When sitting, the weight is frequently placed upon the ischial tuberosity. The gluteus maximus provides cover in the upright posture, but leaves it free in the seated position. The distance between a cyclist's ischial tuberosities is one of the factors in the choice of a bicycle saddle.
Divisions
The tuberosity is divided into two portions: a lower, rough, somewhat triangular part, and an upper, smooth, quadrilateral portion.
The lower portion is subdivided by a prominent longitudinal ridge, passing from base to apex, into two parts:
The outer gives attachment to the adductor magnus
The inner to the sacrotuberous ligament
The upper portion is subdivided into two areas by an oblique ridge, which runs downward and outward:
From the upper and outer area the semimembranosus arises
From the lower and inner, the long head of the biceps femoris and the semitendinosus
Additional images
See also
Ischial bursitis
Sitting disability
Notes
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https://en.wikipedia.org/wiki/Extension%20%28music%29
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In music, an extension is a set of musical notes that lie outside the standard range or tessitura.
Staff
A note that lies outside the lines of a musical staff is an extension of the staff. The note will lie on a ledger line. Middle C, for example, is an extension note on both treble and bass clefs, however is not outside the grand staff. Soprano C and Deep C lie two ledger lines above treble and below bass respectively (as well as the grand staff).
Instruments
An instrumental extension is a range of playable notes outside the normal range of the instrument. A baritone horn, if played by a skillful player, can be played an octave above the normal range. Since this is not standard, these notes would be an extension. (See also: Crook (music)). With the bowed string instruments, lower pitches than the standard range are sometimes used through scordatura in which the lowest string is tuned down a note or two. The double bass sometimes uses a C extension extending the range of the E string downwards to C. Some Bösendorfer pianos have extra keys, extending the range several notes lower than a standard 88-key piano.
Voice
In vocal performance, a singer's extension is all notes that are a part of the singer's vocal range that lie outside the singer's tessitura. This usually include notes that a singer can hit, but does not use on a regular basis. For example, a coloratura soprano regularly, as defined by range, will sing in the whistle register. A standard mezzo-soprano has a range to the high F or G above middle C, however a mezzo-soprano with good head voice extension can rival the coloratura soprano in range. However, since her normal tessitura is mezzo-soprano (or under Soprano C), her abilities in the whistle register would be considered her extension.
Although not commonly thought of, extension can be applied to the lower register as well. A baritone may actually be able to reach depths of low D or E below low C, but is more comfortable in the higher bariton
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https://en.wikipedia.org/wiki/Sonic%20artifact
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In sound and music production, sonic artifact, or simply artifact, refers to sonic material that is accidental or unwanted, resulting from the editing or manipulation of a sound.
Types
Because there are always technical restrictions in the way a sound can be recorded (in the case of acoustic sounds) or designed (in the case of synthesised or processed sounds), sonic errors often occur. These errors are termed artifacts (or sound/sonic artifacts), and may be pleasing or displeasing. A sonic artifact is sometimes a type of digital artifact, and in some cases is the result of data compression (not to be confused with dynamic range compression, which also may create sonic artifacts).
Often an artifact is deliberately produced for creative reasons. For example to introduce a change in timbre of the original sound or to create a sense of cultural or stylistic context. A well-known example is the overdriving of an electric guitar or electric bass signal to produce a clipped, distorted guitar tone or fuzz bass.
Editing processes that deliberately produce artifacts often involve technical experimentation. A good example of the deliberate creation of sonic artifacts is the addition of grainy pops and clicks to a recent recording in order to make it sound like a vintage vinyl record.
Flanging and distortion were originally regarded as sonic artifacts; as time passed they became a valued part of pop music production methods. Flanging is added to electric guitar and keyboard parts. Other magnetic tape artifacts include wow, flutter, saturation, hiss, noise, and print-through.
It is valid to consider the genuine surface noise such as pops and clicks that are audible when a vintage vinyl recording is played back or recorded onto another medium as sonic artifacts, although not all sonic artifacts must contain in their meaning or production a sense of "past", more so a sense of "by-product". Other vinyl record artifacts include turntable rumble, ticks, crackles and groove ec
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https://en.wikipedia.org/wiki/Pelvic%20cavity
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The pelvic cavity is a body cavity that is bounded by the bones of the pelvis. Its oblique roof is the pelvic inlet (the superior opening of the pelvis). Its lower boundary is the pelvic floor.
The pelvic cavity primarily contains the reproductive organs, urinary bladder, distal ureters, proximal urethra, terminal sigmoid colon, rectum, and anal canal. In females, the uterus, Fallopian tubes, ovaries and upper vagina occupy the area between the other viscera.
The rectum is located at the back of the pelvis, in the curve of the sacrum and coccyx; the bladder is in front, behind the pubic symphysis. The pelvic cavity also contains major arteries, veins, muscles, and nerves. These structures coexist in a crowded space, and disorders of one pelvic component may impact upon another; for example, constipation may overload the rectum and compress the urinary bladder, or childbirth might damage the pudendal nerves and later lead to anal weakness.
Structure
The pelvis has an anteroinferior, a posterior, and two lateral pelvic walls; and an inferior pelvic wall, also called the pelvic floor. The parietal peritoneum is attached here and to the abdominal wall.
Lesser pelvis
The lesser pelvis (or "true pelvis") is the space enclosed by the pelvic girdle and below the pelvic brim: between the pelvic inlet and the pelvic floor. This cavity is a short, curved canal, deeper on its posterior than on its anterior wall. Some sources consider this region to be the entirety of the pelvic cavity. Other sources define the pelvic cavity as the larger space including the greater pelvis, just above the pelvic inlet.
The lesser pelvis is bounded in front and below by the superior rami of the symphysis pubis; above and behind, by the sacrum and coccyx; and laterally, by a broad, smooth, quadrangular area of bone, corresponding to the inner surfaces of the body and superior ramus of the ischium, and the part of the ilium below the arcuate line.
The lesser pelvis contains the pelvic colo
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https://en.wikipedia.org/wiki/Hermetic%20storage
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Hermetic storage is a method of using sealed, airtight units to control moisture and insects in stored dry agricultural commodities. The hermetic storage restricts gas exchanges between the internal and external environments and the stored commodity, maintaining the initial levels of moisture and controlling pests by the lack of oxygen.
The available oxygen in the internal ecosystem is reduced to lethal or limiting levels for any living organisms through the biological activity related to gas exchange of the respiration of grains and organisms, allowing the hermetic storage a way to reduce the attack of insects and fungi on the stored food. Hermetic storage also allows for organic storage without chemical pesticides.
See also
Hay steaming
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https://en.wikipedia.org/wiki/Mike%20Trim
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{{Infobox person
| name = Mike Trim
| birth_name = Michael J. Trim
| birth_date =
| birth_place = London, U.K.
| nationality = British
| occupation = Designer, model-maker, and storyboard artist
| years_active = 1964-present
| employer = AP Films (1964–1970)
| notable_works = Thunderbirds Are Go, Captain Scarlet and the Mysterons, Joe 90| television = Thunderbirds}}
Mike Trim (born 26 August 1945) is an artist famous for illustrating the cover of Jeff Wayne's Musical Version of The War of the Worlds, which depicts a Martian tripod striking down the Thunder Child. A book of his illustrations entitled The Future was FAB: The Art of Mike Trim was released in 2006.
Trim grew up in Fulham, and from an early age started to show artistic talent. He studied at London's Sir Christopher Wren School. At the London School of Printing, he did a two-year course in graphic design.
In 1964, his father saw a newspaper advertisement seeking modelmakers for a film company. Upon hearing this, Trim began an odyssey that would last for more than 40 years. Beginning in the final days of Stingray, he would work as a modelmaker and designer for Gerry and Sylvia Anderson's television series Thunderbirds, Captain Scarlet and the Mysterons, Joe 90, The Secret Service, and UFO, as well as their feature films Thunderbirds Are GO, Thunderbird 6, and Journey to the Far Side of the Sun (a.k.a. Doppelgänger).
Starting out in the model shop, Mike eventually became Special Effects director Derek Meddings' assistant in designing the fabulous futuristic vehicles, buildings, and look of the Andersons' imaginative series. Eventually, he would take on the bulk of design work for the series as Meddings became more involved in feature films. Contributing a single (unused) vehicle design and model to Space: 1999, Trim then moved into freelance illustration,
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https://en.wikipedia.org/wiki/Legendre%27s%20equation
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In mathematics, Legendre's equation is the Diophantine equation
The equation is named for Adrien-Marie Legendre who proved in 1785 that it is solvable in integers x, y, z, not all zero, if and only if
−bc, −ca and −ab are quadratic residues modulo a, b and c, respectively, where a, b, c are nonzero, square-free, pairwise relatively prime integers, not all positive or all negative .
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https://en.wikipedia.org/wiki/Interconnect%20bottleneck
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The interconnect bottleneck comprises limits on integrated circuit (IC) performance due to connections between components instead of their internal speed.
In 2006 it was predicted to be a "looming crisis" by 2010.
Improved performance of computer systems has been achieved, in large part, by downscaling the IC minimum feature size. This allows the basic IC building block, the transistor, to operate at a higher frequency, performing more computations per second. However, downscaling of the minimum feature size also results in tighter packing of the wires on a microprocessor, which increases parasitic capacitance and signal propagation delay. Consequently, the delay due to the communication between the parts of a chip becomes comparable to the computation delay itself. This phenomenon, known as an “interconnect bottleneck”, is becoming a major problem in high-performance computer systems.
This interconnect bottleneck can be solved by utilizing optical interconnects to replace the long metallic interconnects. Such hybrid optical/electronic interconnects promise better performance even with larger designs. Optics has widespread use in long-distance communications; still it has not yet been widely used in chip-to-chip or on-chip interconnections because they (in centimeter or micrometer range) are not yet industry-manufacturable owing to costlier technology and lack of fully mature technologies. As optical interconnections move from computer network applications to chip level interconnections, new requirements for high connection density and alignment reliability have become as critical for the effective utilization of these links. There are still many materials, fabrication, and packaging challenges in integrating optic and electronic technologies.
See also
Bus (computing)
Interconnects (integrated circuits)
Network-on-chip
Optical network on chip
Optical interconnect
Photonics
Von Neumann architecture
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https://en.wikipedia.org/wiki/W-algebra
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In conformal field theory and representation theory, a W-algebra is an associative algebra that generalizes the Virasoro algebra. W-algebras were introduced by Alexander Zamolodchikov, and the name "W-algebra" comes from the fact that Zamolodchikov used the letter W for one of the elements of one of his examples.
Definition
A W-algebra is an associative algebra that is generated by the modes of a finite number of meromorphic fields , including the energy-momentum tensor . For , is a primary field of conformal dimension . The generators of the algebra are related to the meromorphic fields by the mode expansions
The commutation relations of are given by the Virasoro algebra, which is parameterized by a central charge . This number is also called the central charge of the W-algebra. The commutation relations
are equivalent to the assumption that is a primary field of dimension .
The rest of the commutation relations can in principle be determined by solving the Jacobi identities.
Given a finite set of conformal dimensions (not necessarily all distinct), the number of W-algebras generated by may be zero, one or more. The resulting W-algebras may exist for all , or only for some specific values of the central charge.
A W-algebra is called freely generated if its generators obey no other relations than the commutation relations. Most commonly studied W-algebras are freely generated, including the W(N) algebras. In this article, the sections on representation theory and correlation functions apply to freely generated W-algebras.
Constructions
While it is possible to construct W-algebras by assuming the existence of a number of meromorphic fields and solving the Jacobi identities, there also exist systematic constructions of families of W-algebras.
Drinfeld-Sokolov reduction
From a finite-dimensional Lie algebra , together with an embedding , a W-algebra may be constructed from the universal enveloping algebra of the affine Lie algebra by a kind of BRST co
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https://en.wikipedia.org/wiki/DNA%20laddering
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DNA laddering is a feature that can be observed when DNA fragments, resulting from Apoptosis DNA fragmentation are visualized after separation by gel electrophoresis the first described in 1980 by Andrew Wyllie at the University Edinburgh medical school DNA fragments can also be delected in cells that underwent necrosis, when theses DNA fragments after separation are subjected to gel electrophoresis which in the results in a characteristic ladder pattern,
DNA degradation
DNA laddering is a distinctive feature of DNA degraded by caspase-activated DNase (CAD), which is a key event during apoptosis. CAD cleaves genomic DNA at internucleosomal linker regions, resulting in DNA fragments that are multiples of 180–185 base-pairs in length. Separation of the fragments by agarose gel electrophoresis and subsequent visualization, for example by ethidium bromide staining, results in a characteristic "ladder" pattern. A simple method of selective extraction of fragmented DNA from apoptotic cells without the presence of high molecular weight DNA sections, generating the laddering pattern, utilizes pretreatment of cells in ethanol.
Apoptosis and necrosis
While most of the morphological features of apoptotic cells are short-lived, DNA laddering can be used as final state read-out method and has therefore become a reliable method to distinguish apoptosis from necrosis. DNA laddering can also be used to see if cells underwent apoptosis in the presence of a virus. This is useful because it can help determine the effects a virus has on a cell.
DNA laddering can only be used to detect apoptosis during the later stages of apoptosis. This is due to DNA fragmentation taking place in a later stage of the apoptosis process. DNA laddering is used to test for apoptosis of many cells, and is not accurate at testing for only a few cells that committed apoptosis. To enhance the accuracy in testing for apoptosis, other assays are used along with DNA laddering such as TEM and TUNEL. With recen
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https://en.wikipedia.org/wiki/Appeal%20to%20nature
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An appeal to nature is an argument or rhetorical tactic in which it is proposed that "a thing is good because it is 'natural', or bad because it is 'unnatural. It is generally considered to be a bad argument because the implicit (unstated) primary premise "What is natural is good" is typically irrelevant, having no cogent meaning in practice, or is an opinion instead of a fact.
Forms
General form of this type of argument:
In some contexts, the use of the terms of "nature" and "natural" can be vague, leading to unintended associations with other concepts. The word "natural" can also be a loaded term – much like the word "normal", in some contexts, it can carry an implicit value judgement. An appeal to nature would thus beg the question, because the conclusion is entailed by the premise.
Opinions differ regarding appeal to nature in rational argument. By some more permissive views, it can sometimes be taken as a helpful rule of thumb in certain limited domains, even if it admits some exceptions. When such a principle is applied as a rule of thumb, natural facts are presumed to provide reliable value judgments regarding what is good, barring evidence to the contrary, and likewise for unnatural facts providing reliable value judgments regarding what is bad. Within a limited domain, treating a rule of thumb such as "all else being equal, you should generally try to eat natural foods" as if it is an exceptionless principle can sometimes involve a fallacy of accident.
Julian Baggini explains the standard view of what makes this a fallacy as follows: "Even if we can agree that some things are natural and some are not, what follows from this? The answer is: nothing. There is no factual reason to suppose that what is natural is good (or at least better) and what is unnatural is bad (or at least worse)."
History
The meaning and importance of various understandings and concepts of "nature" has been a persistent topic of discussion historically in both science and philosoph
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https://en.wikipedia.org/wiki/Supermathematics
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Supermathematics is the branch of mathematical physics which applies the mathematics of Lie superalgebras to the behaviour of bosons and fermions. The driving force in its formation in the 1960s and 1970s was Felix Berezin.
Objects of study include superalgebras (such as super Minkowski space and super-Poincaré algebra), superschemes, supermetrics/supersymmetry, supermanifolds, supergeometry, and supergravity, namely in the context of superstring theory.
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https://en.wikipedia.org/wiki/Beltrami%E2%80%93Klein%20model
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In geometry, the Beltrami–Klein model, also called the projective model, Klein disk model, and the Cayley–Klein model, is a model of hyperbolic geometry in which points are represented by the points in the interior of the unit disk (or n-dimensional unit ball) and lines are represented by the chords, straight line segments with ideal endpoints on the boundary sphere.
The Beltrami–Klein model is named after the Italian geometer Eugenio Beltrami and the German Felix Klein while "Cayley" in Cayley–Klein model refers to the English geometer Arthur Cayley.
The Beltrami–Klein model is analogous to the gnomonic projection of spherical geometry, in that geodesics (great circles in spherical geometry) are mapped to straight lines.
This model is not conformal, meaning that angles and circles are distorted, whereas the Poincaré disk model preserves these.
In this model, lines and segments are straight Euclidean segments, whereas in the Poincaré disk model, lines are arcs that meet the boundary orthogonally.
History
This model made its first appearance for hyperbolic geometry in two memoirs of Eugenio Beltrami published in 1868, first for dimension and then for general n, these essays proved the equiconsistency of hyperbolic geometry with ordinary Euclidean geometry.
The papers of Beltrami remained little noticed until recently and the model was named after Klein ("The Klein disk model"). This happened as follows. In 1859 Arthur Cayley used the cross-ratio definition of angle due to Laguerre to show how Euclidean geometry could be defined using projective geometry. His definition of distance later became known as the Cayley metric.
In 1869, the young (twenty-year-old) Felix Klein became acquainted with Cayley's work. He recalled that in 1870 he gave a talk on the work of Cayley at the seminar of Weierstrass and he wrote:
"I finished with a question whether there might exist a connection between the ideas of Cayley and Lobachevsky. I was given the answer that these t
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https://en.wikipedia.org/wiki/Spinal%20cord%20stimulator
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A spinal cord stimulator (SCS) or dorsal column stimulator (DCS) is a type of implantable neuromodulation device (sometimes called a "pain pacemaker") that is used to send electrical signals to select areas of the spinal cord (dorsal columns) for the treatment of certain pain conditions. SCS is a consideration for people who have a pain condition that has not responded to more conservative therapy. There are also spinal cord stimulators under research and development that could enable patients with spinal cord injury to walk again via epidural electrical stimulation (EES).
Medical uses
The most common use of SCS is failed back surgery syndrome (FBSS) in the United States and peripheral ischemic pain in Europe.
As of 2014 the FDA had approved SCS as a treatment for FBSS, chronic pain, complex regional pain syndrome, intractable angina, as well as visceral abdominal and perineal pain and pain in the extremities from nerve damage.
Once a person has had a psychological evaluation and deemed an appropriate candidate for SCS, a temporary implant is placed, called a trial, to determine the best stimulation pattern, and the person is sent home for three to ten days with an external pulse generator. If pain control and increased activity was achieved, a permanent system, with leads and a pulse generator, is placed.
Contraindications
SCS may be contraindicated in people who have coagulation related disorders, or are on anticoagulant therapy. Other contraindications include local and systemic infection, pacemakers, or those people for whom pre-surgical imaging studies show have anatomy that makes placement difficult, or if concerns arise during psychological evaluation.
Adverse effects and complications
Complications with SCS range from simple easily correctable problems to devastating paralysis, nerve injury and death. In a 7-year follow-up, the overall complication rate was 5–18%. The most common complications include lead migration, lead breakage, and infection. Oth
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