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https://en.wikipedia.org/wiki/Padmaja%20Naidu%20Himalayan%20Zoological%20Park
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Padmaja Naidu Himalayan Zoological Park (also called the Darjeeling Zoo) is a zoo in the town of Darjeeling in the Indian state of West Bengal. The zoo was opened in 1958, and an average elevation of , is the largest high altitude zoo in India. It specializes in breeding animals adapted to alpine conditions, and has successful captive breeding programs for the snow leopard, the endangered Himalayan wolf and the red panda. The zoo attracts about 300,000 visitors every year. The park is named after Padmaja Naidu (1900–1975), daughter of Sarojini Naidu. The zoo serves as the central hub for Central Zoo Authority of India's red panda program and is a member of the World Association of Zoos and Aquariums.
History
A zoo was established on 14 August 1958 in the Birch Hill neighbourhood of Darjeeling under the Department of Education of the Government of West Bengal with a goal to study and preserve Himalayan fauna. Its first Director and founder was Dilip Kumar Dey. Mr. Dey, who belonged to the Indian Forest Service was on deputation to the Department of Education for the express purpose of establishing a high-altitude zoological park specializing mainly in Himalayan flora and fauna. The park's prized possessions were a pair of Siberian (Ussuri) tigers presented to the Government of India by Soviet Premier Nikita Khrushchev in 1960. Over the years famous names in the world of Conservation have been attracted to and have visited the HZP. The zoo now contains endangered animals like snow leopards, red pandas, gorals (mountain goat), Siberian tigers and a variety of endangered birds. However, there has been concern regarding the fact that the Himalayan animals may face a threat due to rising temperatures in the hilly area.
In January 1972, the park became a registered society, with an agreement that maintenance costs would be shared by the central and state governments. In May 1993, the park was transferred to the West Bengal Department of Forests. The park was renamed in
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https://en.wikipedia.org/wiki/Micro-operation
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In computer central processing units, micro-operations (also known as micro-ops or μops, historically also as micro-actions) are detailed low-level instructions used in some designs to implement complex machine instructions (sometimes termed macro-instructions in this context).
Usually, micro-operations perform basic operations on data stored in one or more registers, including transferring data between registers or between registers and external buses of the central processing unit (CPU), and performing arithmetic or logical operations on registers. In a typical fetch-decode-execute cycle, each step of a macro-instruction is decomposed during its execution so the CPU determines and steps through a series of micro-operations. The execution of micro-operations is performed under control of the CPU's control unit, which decides on their execution while performing various optimizations such as reordering, fusion and caching.
Optimizations
Various forms of μops have long been the basis for traditional microcode routines used to simplify the implementation of a particular CPU design or perhaps just the sequencing of certain multi-step operations or addressing modes. More recently, μops have also been employed in a different way in order to let modern CISC processors more easily handle asynchronous parallel and speculative execution: As with traditional microcode, one or more table lookups (or equivalent) is done to locate the appropriate μop-sequence based on the encoding and semantics of the machine instruction (the decoding or translation step), however, instead of having rigid μop-sequences controlling the CPU directly from a microcode-ROM, μops are here dynamically buffered for rescheduling before being executed.
This buffering means that the fetch and decode stages can be more detached from the execution units than is feasible in a more traditional microcoded (or hard-wired) design. As this allows a degree of freedom regarding execution order, it makes some ex
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https://en.wikipedia.org/wiki/Metalink
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Metalink is an extensible metadata file format that describes one or more computer files available for download. It specifies files appropriate for the user's language and operating system; facilitates file verification and recovery from data corruption; and lists alternate download sources (mirror URIs).
The metadata is encoded in HTTP header fields and/or in an XML file with extension or . The duplicate download locations provide reliability in case one method fails. Some clients also achieve faster download speeds by allowing different chunks/segments of each file to be downloaded from multiple resources at the same time (segmented downloading).
Metalink supports listing multiple partial and full file hashes along with PGP signatures. Most clients only support verifying MD5, SHA-1, and SHA-256, however. Besides FTP and HTTP mirror locations and rsync, it also supports listing the P2P methods BitTorrent, ed2k, magnet link or any other that uses a URI.
Development history
Metalink 3.0 was publicly released in 2005. It was designed to aid in downloading Linux ISO images and other large files on release day, when servers would be overloaded (each server would have to be tried manually) and to repair large downloads by replacing only the parts with errors instead of fully re-downloading them. It was initially adopted by download managers, and was used by open source projects such as OpenOffice.org and Linux distributions. A community developed around it, more download programs supported it (including proprietary ones) and it saw commercial adoption. In 2008, the community took their work to the Internet Engineering Task Force which resulted in Metalink 4.0 in 2010, described in a Standards Track RFC. Metalink 3.0 (with the extension ) and Metalink 4.0 (with the extension ) are incompatible because they have a slightly different format. In 2011, another Standards Track RFC described Metalink in HTTP header fields.
Client programs
Client libraries
libmetalink (
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https://en.wikipedia.org/wiki/Influenza%20A%20virus%20subtype%20H5N3
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H5N3 is a subtype of the species Influenza A virus (sometimes called the bird flu virus).
History
H5N3 was identified in Quebec in August 2005 and in Sweden in October 2005.
H5N3 virus was identified at a farm in La Garnache, France in late January 2009. Ninety birds were found dead between 29 January 2009 and 31 January 2009. The remaining stock of 4,932 birds was culled on 1 February 2009.
In Germany, in December 2013, 102 ostriches and 28 chickens in a farm in Blumberg were slaughtered due to suspicion of infection with avian influenza. Samples showed that the birds were infected with the H5N3 virus.
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https://en.wikipedia.org/wiki/Accessory%20obturator%20nerve
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In human anatomy, the accessory obturator nerve is an accessory nerve in the lumbar region present in about 29% of cases.
It is of small size, and arises from the ventral divisions of the third and fourth lumbar nerves. Recent evidence support that this nerve arises from Dorsal divisions.
It descends along the medial border of the psoas major, crosses the superior ramus of the pubis, and passes under the pectineus, where it divides into numerous branches.
One of these supplies the pectineus, penetrating its deep surface, another is distributed to the hip-joint; while a third communicates with the anterior branch of the obturator nerve.
Occasionally the accessory obturator nerve is very small and is lost in the capsule of the hip-joint.
When it is absent, the hip-joint receives two branches from the obturator nerve.
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https://en.wikipedia.org/wiki/Topicity
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In stereochemistry, topicity is the stereochemical relationship between substituents and the structure to which they are attached. Depending on the relationship, such groups can be heterotopic, homotopic, enantiotopic, or diastereotopic.
Homotopic
Homotopic groups in a chemical compound are equivalent groups. Two groups A and B are homotopic if the molecule remains achiral when the groups are interchanged with some other atom (such as bromine) while the remaining parts of the molecule stay fixed. Homotopic atoms are always identical, in any environment. Homotopic NMR-active nuclei have the same chemical shift in an NMR spectrum. For example, the four hydrogen atoms of methane (CH4) are homotopic with one another, as are the two hydrogens or the two chlorines in dichloromethane (CH2Cl2).
Enantiotopic
The stereochemical term enantiotopic refers to the relationship between two groups in a molecule which, if one or the other were replaced, would generate a chiral compound. The two possible compounds resulting from that replacement would be enantiomers.
For example, the two hydrogen atoms attached to the second carbon in butane are enantiotopic. Replacement of one hydrogen atom (colored blue) with a bromine atom will produce (R)-2-bromobutane. Replacement of the other hydrogen atom (colored red) with a bromine atom will produce the enantiomer (S)-2-bromobutane.
Enantiotopic groups are identical and indistinguishable except in chiral environments. For instance, the CH2 hydrogens in ethanol (CH3CH2OH) are normally enantiotopic, but can be made different (diastereotopic) if combined with a chiral center, for instance by conversion to an ester of a chiral carboxylic acid such as lactic acid, or if coordinated to a chiral metal center, or if associated with an enzyme active site, since enzymes are constituted of chiral amino acids. Indeed, in the presence of the enzyme LADH, one specific hydrogen is removed from the CH2 group during the oxidation of ethanol to acetald
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https://en.wikipedia.org/wiki/Inauthentic%20text
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An inauthentic text is a computer-generated expository document meant to appear as genuine, but which is actually meaningless. Frequently they are created in order to be intermixed with genuine documents and thus manipulate the results of search engines, as with Spam blogs. They are also carried along in email in order to fool spam filters by giving the spam the superficial characteristics of legitimate text.
Sometimes nonsensical documents are created with computer assistance for humorous effect, as with Dissociated press or Flarf poetry. They have also been used to challenge the veracity of a publication—MIT students submitted papers generated by a computer program called SCIgen to a conference, where they were initially accepted. This led the students to claim that the bar for submissions was too low.
With the amount of computer generated text outpacing the ability of people to humans to curate it, there needs some means of distinguishing between the two. Yet automated approaches to determining absolutely whether a text is authentic or not face intrinsic challenges of semantics. Noam Chomsky coined the phrase "Colorless green ideas sleep furiously" giving an example of grammatically-correct, but semantically incoherent sentence; some will point out that in certain contexts one could give this sentence (or any phrase) meaning.
The first group to use the expression in this regard can be found below from Indiana University. Their work explains in detail an attempt to detect inauthentic texts and identify pernicious problems of inauthentic texts in cyberspace. The site has a means of submitting text that assesses, based on supervised learning, whether a corpus is inauthentic or not. Many users have submitted incorrect types of data and have correspondingly commented on the scores. This application is meant for a specific kind of data; therefore, submitting, say, an email, will not return a meaningful score.
See also
Scraper site
Spamdexing
Stochastic
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https://en.wikipedia.org/wiki/Microsoft%20Fingerprint%20Reader
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Microsoft Fingerprint Reader was a device sold by Microsoft, primarily for homes and small businesses. The underlying software providing the biometrics was developed by Digital Persona.
Fingerprint readers are more secure, reliable and convenient than a normal traditional password, although they have been subject to spoofing. A fingerprint recognition system is more tightly linked to a specific user than, e.g., an access card, which can be stolen.
History
First released on September 4 2004, this device was supported by Windows XP and Windows Vista x86 operating systems. It was discontinued shortly after Windows Vista was released.
Functionality
The Fingerprint Reader's software allows the registration of up to ten fingerprints per device. Login names and passwords associated with the registered fingerprints were stored in a database on the user's computer.
On presentation of an authorized fingerprint, the software passes the associated login names and passwords to compatible applications and websites, allowing login without a keyboard. If the software finds that the particular fingerprint does not match one it its database, it declines the access.
Application
64-bit Windows
The Microsoft Fingerprint Reader may be modified to work with 64-bit Windows.
Firefox browser
The reader works with Firefox using the FingerFox Add-on.
See also
Fingerprint
Fingerprint Verification Competition
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https://en.wikipedia.org/wiki/Jarkko%20Kari
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Jarkko J. Kari is a Finnish mathematician and computer scientist, known for his contributions to the theory of Wang tiles and cellular automata. Kari is currently a professor at the Department of Mathematics, University of Turku.
Biography
Kari received his Ph.D. in 1990 from the University of Turku; his dissertation, supervised by Arto Salomaa.
He married Lila Kari, a later mathematics student at Turku; they divorced, and afterwards Lila Kari became a professor of computer science at the University of Western Ontario in Canada.
Research
Wang tiles are unit squares with colored markings on each side; they may be used to tesselate the plane, but only with tiles that have matching colors on adjoining edges. The problem of determining whether a set of Wang tiles forms a valid tessellation is undecidable, and its undecidability rests on finding sets of Wang tiles that can only tesselate the plane aperiodically, in such a way that no translation of the plane is a symmetry of the tiling. The first set of aperiodic Wang tiles found, by Robert Berger, had over 20,000 different tiles in it. Kari reduced the size of this set to only 14, by finding a set of tiles that (when used to tile the plane) simulates the construction of a Beatty sequence by Mealy machines. The same approach was later shown to lead to aperiodic sets of 13 tiles, the minimum known. Kari has also shown that the Wang tiling problem remains undecidable in the hyperbolic plane, and has discovered sets of Wang tiles with additional mathematical properties.
Kari has also used the Wang tiling problem as the basis of proofs that several algorithmic problems in the theory of cellular automata are undecidable. In particular, in his thesis research, he showed that it is undecidable to determine whether a given cellular automaton rule in two or more dimensions is reversible. For one-dimensional cellular automata, reversibility is known to be decidable, and Kari has provided tight bounds on the size of the neigh
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https://en.wikipedia.org/wiki/ClamTk
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ClamTk is a free software graphical interface for the ClamAV command line antivirus software program, for Linux desktop users. It provides both on-demand and scheduled scanning. The project was started by Dave Mauroni in February 2004 and remains under development.
ClamTk was originally written using the Tk widget toolkit, for which it is named, but it was later re-written in Perl, using the GTK toolkit. The interface has evolved considerably over time and recent versions are quite different than early releases, adding features and changing the interface presentation. It is dual-licensed under the GNU General Public License version 1 or later, and the Artistic License.
Features
The ClamTk interface allows scanning of single files or directories. It can be configured for recursive scans, scanning all sub-directories, for whitelists, to scan for potentially unwanted applications (PUAs), to exclude hidden files, or large files over 20 MB. In 2017 GHacks reviewer Mike Turcotte-McCusker noted the high rate of false positives that the PUA-inclusive scans return.
The history selection allows reviewing the results of previous scans and quarantined files. ClamTk allows manual or automatic updates to be configured for ClamAV's virus definitions.
The application interfaces with thunar-sendto-clamtk, nemo-sendto-clamtk, clamtk-gnome and clamtk-kde, each of which provide context menu functionality for the associated file managers, Thunar, Nemo, GNOME Files and Dolphin, allowing users to directly send files to ClamTk for scanning.
ClamTk can also be run from the command-line interface, although the main reason that command line access exists is for interface with the various file managers.
Use
ClamTk has been included in the repositories of many Linux distributions, including ALT Linux, Arch Linux, CentOS, Debian, Fedora, Gentoo, Linux Mint, Mandriva, openSUSE, PCLinuxOS, Red Hat Enterprise Linux, Ubuntu, as well as FreeBSD.
Most users install ClamTk from the repositori
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https://en.wikipedia.org/wiki/White%20pulp
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White pulp is a histological designation for regions of the spleen (named because it appears whiter than the surrounding red pulp on gross section), that encompasses approximately 25% of splenic tissue. White pulp consists entirely of lymphoid tissue.
Specifically, the white pulp encompasses several areas with distinct functions:
The periarteriolar lymphoid sheaths (PALS) are typically associated with the arteriole supply of the spleen; they contain T lymphocytes.
Lymph follicles with dividing B lymphocytes are located between the PALS and the marginal zone bordering on the red pulp. IgM and IgG2 are produced in this zone. These molecules play a role in opsonization of extracellular organisms, encapsulated bacteria in particular.
The marginal zone exists between the white pulp and red pulp. It is located farther away from the central arteriole, in proximity to the red pulp. It contains antigen-presenting cells (APCs), such as dendritic cells and macrophages. Some of the white pulp's macrophages are of a specialized kind known as metallophilic macrophages.
Macrophages in the white pulp
The T cell zone (periarteriolar sheath) and B cell follicles contain discrete macrophage populations; however, not much is known about these macrophage populations in terms of their origin and lifespan. These macrophages are not unique to the spleen but instead make up an integral part of the lymphoid parts of all secondary lymphoid organs.
In the B cell follicles, the macrophages are important in clearing the apoptotic B cells that occur during the germinal centre reaction in the process of somatic hypermutation and isotype switching. B cells that cannot form their appropriate receptors will die of apoptosis and are subsequently cleared by the macrophages in the germinal centre. During intensive germinal centre reactions, this process is obvious due to the presence of the large macrophages in the germinal centre, known as tingible body macrophages. (They're named this because
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https://en.wikipedia.org/wiki/Sine%20and%20cosine
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In mathematics, sine and cosine are trigonometric functions of an angle. The sine and cosine of an acute angle are defined in the context of a right triangle: for the specified angle, its sine is the ratio of the length of the side that is opposite that angle to the length of the longest side of the triangle (the hypotenuse), and the cosine is the ratio of the length of the adjacent leg to that of the hypotenuse. For an angle , the sine and cosine functions are denoted simply as and .
More generally, the definitions of sine and cosine can be extended to any real value in terms of the lengths of certain line segments in a unit circle. More modern definitions express the sine and cosine as infinite series, or as the solutions of certain differential equations, allowing their extension to arbitrary positive and negative values and even to complex numbers.
The sine and cosine functions are commonly used to model periodic phenomena such as sound and light waves, the position and velocity of harmonic oscillators, sunlight intensity and day length, and average temperature variations throughout the year. They can be traced to the and functions used in Indian astronomy during the Gupta period.
Notation
Sine and cosine are written using functional notation with the abbreviations sin and cos.
Often, if the argument is simple enough, the function value will be written without parentheses, as rather than as .
Each of sine and cosine is a function of an angle, which is usually expressed in terms of radians or degrees. Except where explicitly stated otherwise, this article assumes that the angle is measured in radians.
Definitions
Right-angled triangle definitions
To define the sine and cosine of an acute angle α, start with a right triangle that contains an angle of measure α; in the accompanying figure, angle α in triangle ABC is the angle of interest. The three sides of the triangle are named as follows:
The opposite side is the side opposite to the angle of i
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https://en.wikipedia.org/wiki/Enterprise%20Distributed%20Object%20Computing
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The UML profile for Enterprise Distributed Object Computing (EDOC) is a standard of the Object Management Group in support of open distributed computing using model-driven architecture and service-oriented architecture. Its aim is to simplify the development of component based (EDOC) systems by providing a UML-based modeling framework conforming to the MDA of the OMG.
The basis of EDOC is the Enterprise Collaboration Architecture, ECA, meta model that defines how roles interact within communities in the performance of collaborative business processes.
The seven EDOC specifications
EDOC is composed of seven specifications:
The Enterprise Collaboration Architecture, ECA
The Metamodel and UML Profile for Java and EJB
The Flow Composition Model, FCM
The UML Profile for Patterns
The UML Profile for ECA
The UML Profile for Meta Object Facility
The UML Profile for Relationships
See also
Model Driven Engineering (MDE)
Model-driven architecture (MDA)
Meta-model
Meta-modeling
Meta-Object Facility (MOF)
Unified Modeling Language (UML)
External links
OMG EDOC Standard at the Internet Archive
Unified Modeling Language
Year of introduction missing
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https://en.wikipedia.org/wiki/Red%20pulp
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The red pulp of the spleen is composed of connective tissue known also as the cords of Billroth and many splenic sinusoids that are engorged with blood, giving it a red color. Its primary function is to filter the blood of antigens, microorganisms, and defective or worn-out red blood cells.
The spleen is made of red pulp and white pulp, separated by the marginal zone; 76-79% of a normal spleen is red pulp. Unlike white pulp, which mainly contains lymphocytes such as T cells, red pulp is made up of several different types of blood cells, including platelets, granulocytes, red blood cells, and plasma.
The red pulp also acts as a large reservoir for monocytes. These monocytes are found in clusters in the Billroth's cords (red pulp cords). The population of monocytes in this reservoir is greater than the total number of monocytes present in circulation. They can be rapidly mobilised to leave the spleen and assist in tackling ongoing infections.
Sinusoids
The splenic sinusoids, are wide vessels that drain into pulp veins which themselves drain into trabecular veins. Gaps in the endothelium lining the sinusoids mechanically filter blood cells as they enter the spleen. Worn-out or abnormal red cells attempting to squeeze through the narrow intercellular spaces become badly damaged, and are subsequently devoured by macrophages in the red pulp. In addition to clearing aged red blood cells, the sinusoids also filter out cellular debris, particles that could clutter up the bloodstream.
Cells found in red pulp
Red pulp consists of a dense network of fine reticular fiber, continuous with those of the splenic trabeculae, to which are applied flat, branching cells. The meshes of the reticulum are filled with blood:
White blood cells are found to be in larger proportion than they are in ordinary blood.
Large rounded cells, termed splenic cells, are also seen; these are capable of ameboid movement, and often contain pigment and red-blood corpuscles in their interior.
The cell
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https://en.wikipedia.org/wiki/Gelsolin
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Gelsolin is an actin-binding protein that is a key regulator of actin filament assembly and disassembly. Gelsolin is one of the most potent members of the actin-severing gelsolin/villin superfamily, as it severs with nearly 100% efficiency.
Cellular gelsolin, found within the cytosol and mitochondria, has a closely related secreted form, Plasma gelsolin, that contains an additional 24 AA N-terminal extension. Plasma gelsolin's ability to sever actin filaments helps the body recover from disease and injury that leaks cellular actin into the blood. Additionally it plays important roles in host innate immunity, activating macrophages and localizing of inflammation.
Structure
Gelsolin is an 82-kD protein with six homologous subdomains, referred to as S1-S6. Each subdomain is composed of a five-stranded β-sheet, flanked by two α-helices, one positioned perpendicular with respect to the strands and one positioned parallel. The β-sheets of the three N-terminal subdomains (S1-S3) join to form an extended β-sheet, as do the β-sheets of the C-terminal subdomains (S4-S6).
Regulation
Among the lipid-binding actin regulatory proteins, gelsolin (like cofilin) preferentially binds polyphosphoinositide (PPI). The binding sequences in gelsolin closely resemble the motifs in the other PPI-binding proteins.
Gelsolin's activity is stimulated by calcium ions (Ca2+). Although the protein retains its overall structural integrity in both activated and deactivated states, the S6 helical tail moves like a latch depending on the concentration of calcium ions. The C-terminal end detects the calcium concentration within the cell. When there is no Ca2+ present, the tail of S6 shields the actin-binding sites on one of S2's helices. When a calcium ion attaches to the S6 tail, however, it straightens, exposing the S2 actin-binding sites. The N-terminal is directly involved in the severing of actin. S2 and S3 bind to the actin before the binding of S1 severs actin-actin bonds and caps the
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https://en.wikipedia.org/wiki/Right%20lymphatic%20duct
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The right lymphatic duct is an important lymphatic vessel that drains the right upper quadrant of the body. It forms various combinations with the right subclavian vein and right internal jugular vein.
Structure
The right lymphatic duct courses along the medial border of the anterior scalene at the root of the neck. The right lymphatic duct forms various combinations with the right subclavian vein and right internal jugular vein. It is approximately 1.25 cm long.
Variations
A right lymphatic duct that enters directly into the junction of the internal jugular and subclavian veins is uncommon.
Function
The right duct drains lymph fluid from:
the upper right section of the trunk, (right thoracic cavity, via the right bronchomediastinal trunk ),
the right arm (via the right subclavian trunk ),
and right side of the head and neck (via the right jugular trunk),
also, in some individuals, the lower lobe of the left lung.
All other sections of the human body are drained by the thoracic duct.
Clinical significance
Along with the thoracic duct, the right lymphatic duct is one of the lymphatic structures most likely to be ruptured in the thorax. This can cause chylothorax.
History
The discovery of this structure has been credited to Niels Stensen.
Additional images
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https://en.wikipedia.org/wiki/Channelling%20%28physics%29
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In condensed-matter physics, channelling (or channeling) is the process that constrains the path of a charged particle in a crystalline solid.
Many physical phenomena can occur when a charged particle is incident upon a solid target, e.g., elastic scattering, inelastic energy-loss processes, secondary-electron emission, electromagnetic radiation, nuclear reactions, etc. All of these processes have cross sections which depend on the impact parameters involved in collisions with individual target atoms. When the target material is homogeneous and isotropic, the impact-parameter distribution is independent of the orientation of the momentum of the particle and interaction processes are also orientation-independent. When the target material is monocrystalline, the yields of physical processes are very strongly dependent on the orientation of the momentum of the particle relative to the crystalline axes or planes. Or in other words, the stopping power of the particle is much lower in certain directions than others. This effect is commonly called the "channelling" effect. It is related to other orientation-dependent effects, such as particle diffraction. These relationships will be discussed in detail later.
History
The channelling effect was first discovered in pioneering binary collision approximation computer simulations in 1963 in order to explain exponential tails in experimentally observed ion range distributions that did not conform to standard theories of ion penetration. The simulated prediction was confirmed experimentally the following year by measurements of ion penetration depths in single-crystalline tungsten. First transmission experiments of ions channelling through crystals were performed by Oak Ridge National Laboratory group showing that ions distribution is determinated by crystal rainbow channelling effect.
Mechanism
From a simple, classical standpoint, one may qualitatively understand the channelling effect as follows: If the direction of a cha
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https://en.wikipedia.org/wiki/Symmetry%20set
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In geometry, the symmetry set is a method for representing the local symmetries of a curve, and can be used as a method for representing the shape of objects by finding the topological skeleton. The medial axis, a subset of the symmetry set is a set of curves which roughly run along the middle of an object.
In 2 dimensions
Let be an open interval, and be a parametrisation of a smooth plane curve.
The symmetry set of is defined to be the closure of the set of centres of circles tangent to the curve at at least two distinct points (bitangent circles).
The symmetry set will have endpoints corresponding to vertices of the curve. Such points will lie at cusp of the evolute. At such points the curve will have 4-point contact with the circle.
In n dimensions
For a smooth manifold of dimension in (clearly we need ). The symmetry set of the manifold is the closure of the centres of hyperspheres tangent to the manifold in at least two distinct places.
As a bifurcation set
Let be an open simply connected domain and . Let be a parametrisation of a smooth piece of manifold.
We may define a parameter family of functions on the curve, namely
This family is called the family of distance squared functions. This is because for a fixed the value of is the square of the distance from to at
The symmetry set is then the bifurcation set of the family of distance squared functions. I.e. it is the set of such that has a repeated singularity for some
By a repeated singularity, we mean that the jacobian matrix is singular. Since we have a family of functions, this is equivalent to .
The symmetry set is then the set of such that there exist with , and
together with the limiting points of this set.
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https://en.wikipedia.org/wiki/Acetabular%20notch
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The acetabular notch is a deep notch in the inferior portion of the rim of the acetabulum. It is bridged by the transverse acetabular ligament, converting it into a foramen (through which nerves and vessels (including the acetabular notch of obturator artery) pass into the hip joint cavity). It is continuous with space of the acetabular fossa. The lunate surface of acetabulum is discontinued opposite the notch.
The ligament of the head of the femur attaches at the margins of the notch. The anterior margin of the acetabular notch presents a posterior obturator tubercle onto which the obturator membrane attaches.
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https://en.wikipedia.org/wiki/Cruciate%20anastomosis
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The cruciate anastomosis is a circulatory anastomosis in the upper thigh formed by the inferior gluteal artery, the lateral and medial circumflex femoral arteries, the first perforating artery of the deep femoral artery, and the anastomotic branch of the posterior branch of the obturator artery.
The cruciate anastomosis is clinically relevant because if there is a blockage between the femoral artery and external iliac artery, blood can reach the popliteal artery by means of the anastomosis. The route of blood is through the internal iliac, to the inferior gluteal artery, to a perforating branch of the deep femoral artery, to the lateral circumflex femoral artery, then to its descending branch into the superior lateral genicular artery and thus into the popliteal artery.
Structure
The cruciate anastomosis is so-called because it resembles a cross.
Its four components are:
Inferior gluteal artery
Transverse branches of the lateral circumflex femoral artery and the medial circumflex femoral artery
Ascending branch of the first perforating artery from the deep femoral artery
See also
Trochanteric anastomosis
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https://en.wikipedia.org/wiki/Lateral%20umbilical%20fold
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The lateral umbilical fold is an elevation (on either side of the body) of the peritoneum lining the inner/posterior surface of the lower anterior abdominal wall formed by the underlying inferior epigastric artery and inferior epigastric vein which the peritoneum covers. Superiorly, the lateral umbilical fold ends where the vessels reach and enter the rectus sheath at the arcuate line of rectus sheath; in spite of the name, the lateral umbilical folds do not extend as far superiorly as the umbilicus. Inferiorly, it extends to just medial to the deep inguinal ring.
Each lateral umbilical fold is situated lateral to the ipsilateral medial umbilical fold. Unlike the median and medial umbilical folds, the contents of the lateral umbilical fold remain functional after birth.
Clinical significance
The lateral umbilical fold is an important reference site with regards to hernia classification. A direct hernia occurs medial to the lateral umbilical fold, whereas an indirect hernia originates lateral to the fold. This latter case is due to the placement of the opening of the deep inguinal ring in the space lateral to the lateral umbilical fold, which allows the passage of the ductus deferens, testicular artery, and other components of the spermatic cord in men, or the round ligament of the uterus in women.
Additional images
See also
Median umbilical ligament
Medial umbilical ligament
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https://en.wikipedia.org/wiki/Iliofemoral%20ligament
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The iliofemoral ligament is a thick and very though triangular capsular ligament of the hip joint situated anterior to this joint. It attaches superiorly at the inferior portion of the anterior inferior iliac spine and adjacent portion of the margin of the acetabulum; it attaches inferiorly at the intertrochanteric line.
It is also referred to as the Y-ligament (see below). the ligament of Bigelow, the ligament of Bertin and any combinations of these names.
With a force strength exceeding 350 kg (772 lbs), the iliofemoral ligament is not only stronger than the two other ligaments of the hip joint, the ischiofemoral and the pubofemoral, but also the strongest ligament in the human body and as such is an important constraint to the hip joint.
Structure
The ligament is triangular in shape, with its apex represented by its pelvic attachment. The ligament has two though outer bands; it is thinner and weaker centrally. As the lateral portion is twisted like a screw, the two parts together take the form of an inverted Y.
Arising from the anterior inferior iliac spine and the rim of the acetabulum, the iliofemoral ligament spreads obliquely downwards and laterally to the intertrochanteric line on the anterior side of the femoral head. It is divided into two parts or bands which act differently: the transverse part above, is strong and runs parallel to the axis of the femoral neck. The descending part below, is weaker and runs parallel to the femoral shaft.
It is intimately connected with the joint capsule, and serves to strengthen the joint by resisting hyperextension. Its upper band is sometimes named the iliotrochanteric ligament. Between the two bands is a thinner part of the capsule. In some cases there is no division, and the ligament spreads out into a flat triangular band which is attached to the whole length of the intertrochanteric line.
Function
In a standing posture, when the pelvis is tilted posteriorly, the ligament is twisted and tense, which preven
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https://en.wikipedia.org/wiki/Pubofemoral%20ligament
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The pubofemoral ligament (or pubocapsular ligament) is a ligament which reinforces the inferior and anterior portions of the joint capsule of the hip joint. The ligament attaches superiorly at the superior ramus of pubis, and the iliopubic eminence; it attaches inferiorly at the inferior portion of the intertrochanteric line (here blending with the inferior band of iliofemoral ligament). The psoas bursa intervenes between the ligament and joint capsule.
The ligament resists hyper-abduction of the hip joint.
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https://en.wikipedia.org/wiki/Ligament%20of%20head%20of%20femur
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The ligament of the head of the femur (round ligament of the femur, foveal ligament, or Fillmore’s ligament) is a weak ligament located in the hip joint. It is triangular in shape and somewhat flattened. The ligament is implanted by its apex into the anterosuperior part of the fovea capitis femoris and its base is attached by two bands, one into either side of the acetabular notch, and between these bony attachments it blends with the transverse ligament.
Anatomy
Development
Initially, the ligament contains a small artery (the acetabular branch of the obturator artery) which becomes obliterated in late childhood.
Variation
It is ensheathed by the synovial membrane, and varies greatly in strength in different subjects; occasionally only the synovial fold exists, and in rare cases even this is absent.
Function
The ligament becomes taught when the thigh is flexed and either adducted or laterally/externally rotated. The ligament is usually too weak to actually function as a ligament past childhood; excessive movement at the hip joint is instead primarily limited by the three capsular ligament of the hip joint. Nevertheless, more recent research suggests the ligament may have a number of functions, including a significant biomechanical role on the basis of cadaveric studies where increases of range of motion were seen after sectioning of the ligament.
Other animals
It has been suggested that some animals, such as the orangutan and Indian elephant, lack a ligamentum teres. However, the presence of a ligamentum teres, albeit with a morphology different from the human version, has been found upon dissection in both these animals. In the orangutan, it is believed to play a significant role in preventing dislocation of the femoral head within extreme ranges of motion. In the Indian elephant, it is the primary support of the hip joint when the hind limbs are abducted.
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https://en.wikipedia.org/wiki/Edwin%20Stephen%20Goodrich
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Edwin Stephen Goodrich FRS (Weston-super-Mare, 21 June 1868 – Oxford, 6 January 1946), was an English zoologist, specialising in comparative anatomy, embryology, palaeontology, and evolution. He held the Linacre Chair of Zoology in the University of Oxford from 1921 to 1946. He served as editor of the Quarterly Journal of Microscopical Science from 1920 until his death.
Life
Goodrich's father died when he was only two weeks old, and his mother took her children to live with her mother at Pau, France, where he attended the local English school and a French lycée. In 1888 he entered the Slade School of Art at University College London; there he met E. Ray Lankester, who interested him in zoology.
On coming to Oxford from London, Goodrich entered Merton College, Oxford as an undergraduate in 1891 and, while acting as assistant to Lankester, read for the final honour school in Zoology; he was awarded the Rolleston Memorial Prize in 1894 and graduated with first-class honours the following year.
In 1913 Goodrich married Helen Pixell, a distinguished protozoologist, who helped greatly with his work. His artistic training always stood him in good stead. He drew diagrams of beauty and clarity whilst lecturing (students used to photograph the blackboard before it was erased), and in his books and papers. He also exhibited his watercolor landscapes in London. Goodrich was elected Fellow of the Royal Society in 1905 and received its Royal Medal in 1936. He was honorary member of the New York Academy of Science and of many other academies, and awarded many honorary doctorates. In 1945 Lev Berg of Leningrad sent a message through Julian Huxley: "Please tell [Goodrich] that... we all regard ourselves as his pupils." A small, dapper, thin man with a dry sense of humor, he always complained that, when travelling by air, he was not weighed with his luggage, since his own weight was only half that of an average passenger.
Career
When Lankester became Linacre Professor of Compar
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https://en.wikipedia.org/wiki/Beta%20barrel
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In protein structures, a beta barrel is a beta sheet composed of tandem repeats that twists and coils to form a closed toroidal structure in which the first strand is bonded to the last strand (hydrogen bond). Beta-strands in many beta-barrels are arranged in an antiparallel fashion. Beta barrel structures are named for resemblance to the barrels used to contain liquids. Most of them are water-soluble proteins and frequently bind hydrophobic ligands in the barrel center, as in lipocalins. Others span cell membranes and are commonly found in porins. Porin-like barrel structures are encoded by as many as 2–3% of the genes in Gram-negative bacteria. It has been shown that more than 600 proteins with various function (e.g., oxidase, dismutase, amylase) contain the beta barrel structure.
In many cases, the strands contain alternating polar and non-polar (hydrophilic and hydrophobic) amino acids, so that the hydrophobic residues are oriented into the interior of the barrel to form a hydrophobic core and the polar residues are oriented toward the outside of the barrel on the solvent-exposed surface. Porins and other membrane proteins containing beta barrels reverse this pattern, with hydrophobic residues oriented toward the exterior where they contact the surrounding lipids, and hydrophilic residues oriented toward the aqueous interior pore.
All beta-barrels can be classified in terms of two integer parameters: the number of strands in the beta-sheet, n, and the "shear number", S, a measure of the stagger of the strands in the beta-sheet. These two parameters (n and S) are related to the inclination angle of the beta strands relative to the axis of the barrel.
Types
Up-and-down
Up-and-down barrels are the simplest barrel topology and consist of a series of beta strands, each of which is hydrogen-bonded to the strands immediately before and after it in the primary sequence.
Jelly roll
The jelly roll fold or barrel, also known as the Swiss roll, typically comprises eig
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https://en.wikipedia.org/wiki/Protoclepsydrops
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Protoclepsydrops is an extinct genus of early synapsids, found in Joggins, Nova Scotia. The name means 'first Clepsydrops''', and refers to it being the predecessor of the other early synapsid Clepsydrops.
Description
Like Archaeothyris, Protoclepsydrops resembled a modern lizard in superficial appearance. However, Protoclepsydrops had primitive vertebrae with tiny neural processes typical of their amniote ancestors. Protoclepsydrops is known from a few vertebrae and some humeri.
Classification
Its skeletal remains indicate that it may have been more closely related to synapsids than to sauropsids, making it a possible stem-mammal. If so, it is the oldest synapsid known, though its status is unconfirmed because its remains are too fragmentary. Protoclepsydrops lived slightly earlier than Archaeothyris.
See also
List of pelycosaurs
Evolution of mammals
List of transitional fossils
Carboniferous tetrapods
Clepsydrops''
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https://en.wikipedia.org/wiki/Normal%20measure
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In set theory, a normal measure is a measure on a measurable cardinal κ such that the equivalence class of the identity function on κ maps to κ itself in the ultrapower construction. Equivalently, if f:κ→κ is such that f(α)<α for most α<κ, then there is a β<κ such that f(α)=β for most α<κ. (Here, "most" means that the set of elements of κ where the property holds is a member of the ultrafilter, i.e. has measure 1.) Also equivalent, the ultrafilter (set of sets of measure 1) is closed under diagonal intersection.
For a normal measure, any closed unbounded (club) subset of κ contains most ordinals less than κ. And any subset containing most ordinals less than κ is stationary in κ.
If an uncountable cardinal κ has a measure on it, then it has a normal measure on it.
See also
Measurable cardinal
Club set
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https://en.wikipedia.org/wiki/Memory%20latency
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Memory latency is the time (the latency) between initiating a request for a byte or word in memory until it is retrieved by a processor. If the data are not in the processor's cache, it takes longer to obtain them, as the processor will have to communicate with the external memory cells. Latency is therefore a fundamental measure of the speed of memory: the less the latency, the faster the reading operation.
Latency should not be confused with memory bandwidth, which measures the throughput of memory. Latency can be expressed in clock cycles or in time measured in nanoseconds. Over time, memory latencies expressed in clock cycles have been fairly stable, but they have improved in time.
See also
Burst mode (computing)
CAS latency
Multi-channel memory architecture
Interleaved memory
SDRAM burst ordering
SDRAM latency
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https://en.wikipedia.org/wiki/Dermatoglyphics
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Dermatoglyphics (from Ancient Greek derma, "skin", and glyph, "carving") is the scientific study of fingerprints, lines, mounts and shapes of hands, as distinct from the superficially similar pseudoscience of palmistry.
Dermatoglyphics also refers to the making of naturally occurring ridges on certain body parts, namely palms, fingers, soles, and toes. These are areas where hair usually does not grow, and these ridges allow for increased leverage when picking up objects or walking barefoot.
In a 2009 report, the scientific basis underlying dermatoglyphics was questioned by the National Academy of Sciences, for the discipline's reliance on subjective comparisons instead of conclusions drawn from the scientific method.
History
1823 marks the beginning of the scientific study of papillary ridges of the hands and feet, with the work of Jan Evangelista Purkyně.
By 1858, Sir William Herschel, 2nd Baronet, while in India, became the first European to realize the value of fingerprints for identification.
Sir Francis Galton conducted extensive research on the importance of skin-ridge patterns, demonstrating their permanence and advancing the science of fingerprint identification with his 1892 book Fingerprints.
In 1893, Sir Edward Henry published the book The classification and uses of fingerprints, which marked the beginning of the modern era of fingerprint identification and is the basis for other classification systems.
In 1929, Harold Cummins and Charles Midlo M.D., together with others, published the influential book Fingerprints, Palms and Soles, a bible in the field of dermatoglyphics.
In 1945, Lionel Penrose, inspired by the works of Cummins and Midlo, conducted his own dermatoglyphic investigations as a part of his research into Down syndrome and other congenital medical disorders.
In 1976, Schaumann and Alter published the book Dermatoglyphics in Medical Disorders, which summarizes the findings of dermatoglyphic patterns under disease conditions.
In 1982,
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https://en.wikipedia.org/wiki/Rushbrooke%20inequality
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In statistical mechanics, the Rushbrooke inequality relates the critical exponents of a magnetic system which exhibits a first-order phase transition in the thermodynamic limit for non-zero temperature T.
Since the Helmholtz free energy is extensive, the normalization to free energy per site is given as
The magnetization M per site in the thermodynamic limit, depending on the external magnetic field H and temperature T is given by
where is the spin at the i-th site, and the magnetic susceptibility and specific heat at constant temperature and field are given by, respectively
and
Definitions
The critical exponents and are defined in terms of the behaviour of the order parameters and response functions near the critical point as follows
where
measures the temperature relative to the critical point.
Derivation
For the magnetic analogue of the Maxwell relations for the response functions, the relation
follows, and with thermodynamic stability requiring that , one has
which, under the conditions and the definition of the critical exponents gives
which gives the Rushbrooke inequality
Remarkably, in experiment and in exactly solved models, the inequality actually holds as an equality.
Critical phenomena
Statistical mechanics
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https://en.wikipedia.org/wiki/Bulk%20soil
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Bulk soil is soil outside the rhizosphere that is not penetrated by plant roots. The bulk soil is like an ecosystem, it is made up of many things such as: nutrients, ions, soil particles, and root exudates. There are many different interactions that occur between all the members of the bulk soil. Natural organic compounds are much lower in bulk soil than in the rhizosphere. Furthermore, bulk soil inhabitants are generally smaller than identical species in the rhizosphere. The main two aspects of bulk soil are its chemistry and microbial community composition.
Chemistry of bulk soil
Soil is made up of layers called soil horizons, these make up a vertical soil profile. There are five master horizons O, A, E, B, and C. The O horizon contains organic matter, A is considered the topsoil, E is present or absent depending on the type of soil and conditions, B is the subsoil, and C is unconsolidated rock. There are many chemical interactions and properties that are in all the soil. Chemical properties of the bulk soil are organic matter, carbon, nutrient content, cation-exchange capacity (CEC), free ions (cations or anions), pH, and base saturation and organisms. These can impact many chemical processes such as nutrient cycling, soil formation, biological activity, and erosion.
Microbial communities
Soil is composed of a diverse community of microbes such as: fungi, bacteria, archaea, viruses and microfauna. There are microbes in the bulk soil and the rhizosphere, the variation of microbes increases in the bulk soil and the abundance of microbes increases in the rhizosphere. Some microbes can form symbioses with plants that are beneficial or pathogenic. All these microbes have a special role in many soil processes such as soil formation, organic matter decomposition, nutrient cycling. For example, there are microbes in the rhizosphere (on the plant) that can break down nitrogen, and microbes out in the bulk can break down nitrogen as well. Both have different factors
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https://en.wikipedia.org/wiki/Co-adaptation
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In biology, co-adaptation is the process by which two or more species, genes or phenotypic traits undergo adaptation as a pair or group. This occurs when two or more interacting characteristics undergo natural selection together in response to the same selective pressure or when selective pressures alter one characteristic and consecutively alter the interactive characteristic. These interacting characteristics are only beneficial when together, sometimes leading to increased interdependence. Co-adaptation and coevolution, although similar in process, are not the same; co-adaptation refers to the interactions between two units, whereas co-evolution refers to their evolutionary history. Co-adaptation and its examples are often seen as evidence for co-evolution.
Genes and Protein Complexes
At genetic level, co-adaptation is the accumulation of interacting genes in the gene pool of a population by selection. Selection pressures on one of the genes will affect its interacting proteins, after which compensatory changes occur.
Proteins often act in complex interactions with other proteins and functionally related proteins often show a similar evolutionary path. A possible explanation is co-adaptation. An example of this is the interaction between proteins encoded by mitochondrial DNA (mtDNA) and nuclear DNA (nDNA). MtDNA has a higher rate of evolution/mutation than nDNA, especially in specific coding regions. However, in order to maintain physiological functionality, selection for functionally interacting proteins, and therefore co-adapted nDNA will be favourable.
Co-adaptation between mtDNA and nDNA sequences has been studied in the copepod Tigriopus californicus. The mtDNA of COII coding sequences among conspecific populations of this species diverges extensively. When mtDNA of one population was placed in a nuclear background of another population, cytochrome c oxidase activity is significantly decreased, suggesting co-adaptation. Results show an unlikely relation
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https://en.wikipedia.org/wiki/Terfeziaceae
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The Terfeziaceae, or desert truffles, is a family of truffles (, , , ) endemic to arid and semi-arid areas of the Mediterranean Region, North Africa, and the Middle East, where they live in ectomycorrhizal association with Helianthemum species and other ectomycorrhizal plants (including Cistus, oaks, and pines). This group consists of three genera: Terfezia, Tirmania, and Mattirolomyces. They are a few centimetres across and weigh from 30 to 300 grams (1–10 oz). Desert truffles are often used as a culinary ingredient.
Family description
Fruit-bodies (ascomata) are large, more or less spherical to turbinate (top-shaped), thick-walled, and solid. The asci are formed in marbled veins interspersed with sterile tissue. The asci are cylindrical to spherical, indehiscent (not splitting open at maturity), and sometimes stain blue in iodine. Ascospores are hyaline to pale brown, spherical, and uninucleate.
Habitat and ecology
Desert truffles, as the name suggests, predominantly grow in the desert. They have been found in arid and semi-arid zones of the Kalahari desert, the Mediterranean basin, Syria, Azerbaijan, Iran, Iraq, Kuwait, the Negev desert in Palestine, the Sahara, Saudi Arabia, Qatar, Libya, Spain, Greece, Cyprus, Hungary, Croatia, and China. They can be formed near Sunrose (Helianthemum) plants, but they are very rare to find and can't be cultivated (thus justifying their cost).
Culinary use and commercial importance
Desert truffles do not have the same flavor as European truffles, but tend to be more common and thus more affordable. Forest truffles (genus Tuber) typically cost $1000 per kilogram, and Italian truffles may sell for up to $2,200 per kilogram, while Terfezia truffles sold as of 2002 in Riyadh for $200 to $305 a kilo, and in recent years have reached, but not yet exceeded, $570. Israeli agricultural scientists have been attempting to domesticate Terfezia boudieri into a commercial crop.
Vernacular names
Desert truffles go by several different nam
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https://en.wikipedia.org/wiki/HM%20Government%20Communications%20Centre
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His Majesty's Government Communications Centre (HMGCC) is an organisation which provides electronics and software to support the communication needs of the British Government. Based at Hanslope Park, near Milton Keynes in Buckinghamshire, it is closely linked with the Foreign, Commonwealth and Development Office and the British intelligence community.
History
HMGCC used to have a communications centre at Signal Hill near Gawcott, in Buckinghamshire. Stephen Ball was Chief Executive until 2000, when Dr John Widdowson took over; Widdowson moved to GCHQ in 2005. Sarah-Jill Lennard was CEO from 2008 to 2011. Juliette Wilcox was CEO from 2019 to 2021.
Structure
The organisation employs more than 380 personnel and the solutions it provides are bespoke to fit the needs of the government, its organisations, and specifically its intelligence assets. HMGCC is responsible for research and design in the following disciplines:
RF engineering
Signal processing
Software engineering
Acoustics
Audio engineering
Operating systems
GUI design
Embedded systems
System engineering
Manufacture and application of microcircuits
Study of power sources
Operational research
Mechanical engineering
See also
GCHQ
MI5
MI6
Bletchley Park
Hanslope Park
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https://en.wikipedia.org/wiki/Svenskt%20Diplomatarium
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Svenskt Diplomatarium (also known under the Latin name Diplomatarium Suecanum) is a series of critical editions of medieval Swedish documents or documents pertaining to the history of Sweden (in Swedish, Latin and other languages).
Begun in the 1820s by the antiquarian Johan Gustaf Liljegren and inactive for periods, the work is since 1976 in the hands of a department within the Swedish National Archives. The editorial committee works through the material in chronological order, and the fascicle published in 2004 included documents dating to the 1370s.
Since 1999, the editorial committee has published the index of known medieval documents (including those from the periods not yet covered by the printed fascicles in a database available first on a compact disc, later on the World Wide Web. Many documents are also available online in full text and with colour images of the originals.
Historiography of Sweden
Online databases
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https://en.wikipedia.org/wiki/TMS6100
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The Texas Instruments TMS6100 is a 1 or 4-bit serial mask (factory)-programmed read-only memory IC. It is a companion chip to the TMS5100, CD2802, TMS5110, (rarely) TMS5200, and (rarely) TMS5220 speech synthesizer ICs, and was mask-programmed with LPC data required for a specific product. It holds 128Kib (16KiB) of data, and is mask-programmed with a start address for said data on a 16KiB boundary. It is also mask-programmable whether the /CE line needs to be high or low to activate, and also what the two (or four) 'internal' CE bits need to be set to activate, effectively making the total addressable area 18 bits. Finally, it is mask-programmable whether the bits are read out 1-bit serially or 4 at a time.
TMS6125
The TMS6125 is a smaller, 32Kib (4KiB) version of effectively the same chip, with some minor changes to the 'address load' command format to reflect its smaller size.
Texas Instruments calls both of these serial roms (TMS6100 and TMS6125) "VSM"s (Voice Synthesis Memory) on their datasheets and literature, and they will be referred to as such for the rest of this article.
Both VSMs use 'local addressing', meaning the chip keeps track of its own address pointer once loaded. Hence every bit in the chip can be sequentially read out, even though internally the chip stores data in 8-bit bytes.
(For the following section, CE stands for "Chip Enable" and is used as a way to enable one specific VSM)
Commands
The VSM has supports 4 basic commands, based on two input pins called 'M0' and 'M1':
no operation/idle: this command tells the chip to 'do nothing' or 'continue doing what was being done before'.
load address: this command parallel-loads 4 bits from the data bus. to fully load an address, this command must be executed 5 times in sequence, for a load of a 20 bit block (LSB-first 14 bit address, 4 CE bits, and two unused bits, effectively 18 address bits) into the internal address pointer. On the TMS6125 the command must be executed 4 times instead, and o
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https://en.wikipedia.org/wiki/Center%20Excellence%20in%20Molecular%20Biology
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Centre of Excellence in Molecular Biology (CEMB) is a highly distinguished biological research institute in Asia, located on the West Bank of the picturesque Canal Road Lahore, Punjab, Pakistan. It is an autonomous organization that is under administrative control of University of the Punjab, Lahore, Pakistan.
History
On 1 November 1981, University of the Punjab announced the "birth" of the centre. In April, 1983 the Federal Government allocated a sum of 1.635 million rupees to create a nucleus laboratory of the centre. In November, 1985 the proposal to establish the Centre for Advanced Molecular Biology (CAMB) was approved at a cost of 24.55 million rupees. In 1986, the CAMB project was upgraded into a Centre of Excellence in Molecular Biology (CEMB) and the cost of setting it up was subsequently revised in January 1991, to 44.33 million rupees. In April 1987, the Federal Ministry of Science & Technology (MOST) approved the establishment of a Centre for Applied Molecular Biology (CAMB), located back to back with the laboratory block of the Centre of Excellence in Molecular Biology (CEMB).
The CEMB established nucleus laboratories in March, 1985 in two student laboratories of the Department of Zoology, University of the Punjab, Quaid-e-Azam Campus, Lahore. Construction work on the CEMB building started in 1987 on a site located in Lahore's southern suburb of Thokar Niaz Baig along the Canal. The scientific staff moved into the new building in late 1992–93.
Admission process
The centre offers M.Phil and Ph.D. in Molecular Biology. Annually, only 20-30 position for academically brilliant students with research aptitude, from all over the world, are available for M.Phil and Ph.D. The admission process is one of the toughest and highly competitive in Pakistan with admission rate of around 10% annually. A greater number of foreign scholars are also pursuing their M.Phil and PhD in the centre.
Research groups
CEMB has the following research groups:
Applied and
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https://en.wikipedia.org/wiki/Avi%20Loeb
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Abraham "Avi" Loeb (; born February 26, 1962) is an Israeli-American theoretical physicist who works on astrophysics and cosmology. Loeb is the Frank B. Baird Jr. Professor of Science at Harvard University, where since 2007 he has been Director of the Institute for Theory and Computation at the Center for Astrophysics. He chaired the Department of Astronomy from 2011–2020, and founded the Black Hole Initiative in 2016.
Loeb is a fellow of the American Academy of Arts and Sciences, the American Physical Society, and the International Academy of Astronautics. In 2015, he was appointed as the science theory director for the Breakthrough Initiatives of the Breakthrough Prize Foundation.
Loeb has published popular science books including Extraterrestrial: The First Sign of Intelligent Life Beyond Earth (2021) and Interstellar: The Search for Extraterrestrial Life and Our Future in the Stars (2023).
In 2018, he suggested that alien space craft may be in the Solar System, using ʻOumuamua as an example. In 2023, he claimed to have recovered material from an interstellar meteor that could be evidence of an alien starship, claims some experts criticized as hasty and sensational.
Life and career
Loeb was born in Beit Hanan, Israel, in 1962. He took part in the national Talpiot program of the Israeli Defense Forces at age 18. While in Talpiot, he obtained a BSc degree in physics and mathematics in 1983, an MSc degree in physics in 1985, and a PhD in physics in 1986, all from the Hebrew University of Jerusalem (HUJI). From 1983 to 1988, he led the first international project supported by the U.S. Strategic Defense Initiative. Between 1988 and 1993, Loeb was a long-term member at the Institute for Advanced Study at Princeton, where he started to work in theoretical astrophysics.
In 1993, he moved to Harvard University as an assistant professor in the department of astronomy, and was tenured three years later.
Loeb has written eight books, including textbooks How Did the F
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https://en.wikipedia.org/wiki/Conway%20polyhedron%20notation
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In geometry, Conway polyhedron notation, invented by John Horton Conway and promoted by George W. Hart, is used to describe polyhedra based on a seed polyhedron modified by various prefix operations.
Conway and Hart extended the idea of using operators, like truncation as defined by Kepler, to build related polyhedra of the same symmetry. For example, represents a truncated cube, and , parsed as , is (topologically) a truncated cuboctahedron. The simplest operator dual swaps vertex and face elements; e.g., a dual cube is an octahedron: . Applied in a series, these operators allow many higher order polyhedra to be generated. Conway defined the operators (ambo), (bevel), (dual), (expand), (gyro), (join), (kis), (meta), (ortho), (snub), and (truncate), while Hart added (reflect) and (propellor). Later implementations named further operators, sometimes referred to as "extended" operators. Conway's basic operations are sufficient to generate the Archimedean and Catalan solids from the Platonic solids. Some basic operations can be made as composites of others: for instance, ambo applied twice is the expand operation (), while a truncation after ambo produces bevel ().
Polyhedra can be studied topologically, in terms of how their vertices, edges, and faces connect together, or geometrically, in terms of the placement of those elements in space. Different implementations of these operators may create polyhedra that are geometrically different but topologically equivalent. These topologically equivalent polyhedra can be thought of as one of many embeddings of a polyhedral graph on the sphere. Unless otherwise specified, in this article (and in the literature on Conway operators in general) topology is the primary concern. Polyhedra with genus 0 (i.e. topologically equivalent to a sphere) are often put into canonical form to avoid ambiguity.
Operators
In Conway's notation, operations on polyhedra are applied like functions, from right to left. For example, a
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https://en.wikipedia.org/wiki/End%20of%20message
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End of message or EOM (as in "(EOM)" or "<EOM>") signifies the end of a message, often an e-mail message.
Usage
The subject of an e-mail message may contain such an abbreviation to signify that all content is in the subject line so that the message itself does not need to be opened (e.g., "No classes Monday (EOM)" or "Midterm delayed <EOM>"). This practice can save the time of the receiver and has been recommended to increase productivity.
EOM can also be used in conjunction with no reply necessary, or NRN, to signify that the sender does not require (or would prefer not to receive) a response (e.g., "Campaign has launched (EOM/NRN)") or reply requested or RR to signify that the sender wishes a response (e.g., "Got a minute? (EOM/RR)"). These are examples of Internet slang.
EOM is often used this way, as a synonym to NRN, in blogs and forums online. It is often a snide way for commenters to imply that their message is so perfect that there can be no logical response to it. Or it can be used as a way of telling another specific poster to stop writing back.
EOM can also be defined as the final 3 buzzes of an alert of the Emergency Alert System to know when the alert is finished.
Origin
In earlier communications methods, an end of message ("EOM") sequence of characters indicated to a receiving device or operator that the current message has ended. In teleprinter systems, the sequence "NNNN", on a line by itself, is an end of message indicator. In several Morse code conventions, including amateur radio, the prosign AR (dit dah dit dah dit) means end of message.
In the original ASCII code, "EOM" corresponded to code 03hex, which has since been renamed to "ETX" ("end of text").
See also
EOM (disambiguation)
End-of-file, also abbreviated EOF
List of computing and IT abbreviations
-30-
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https://en.wikipedia.org/wiki/Orbitrap
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In mass spectrometry, Orbitrap is an ion trap mass analyzer consisting of an outer barrel-like electrode and a coaxial inner spindle-like electrode that traps ions in an orbital motion around the spindle. The image current from the trapped ions is detected and converted to a mass spectrum using the Fourier transform of the frequency signal.
History
The concept of electrostatically trapping ions in an orbit around a central spindle was developed by Kenneth Hay Kingdon in the early 1920s. The Kingdon trap consists of a thin central wire and an outer cylindrical electrode. A static applied voltage results in a radial logarithmic potential between the electrodes. In 1981, Knight introduced a modified outer electrode that included an axial quadrupole term that confines the ions on the trap axis. Neither the Kingdon nor the Knight configurations were reported to produce mass spectra.
The invention of the Orbitrap analyzer and its proof-of-principle by Makarov at the end of the 1990s started a sequence of technology improvements which resulted in the commercial introduction of this analyzer by Thermo Fisher Scientific as a part of the hybrid LTQ Orbitrap instrument in 2005.
Principle of operation
Trapping
In the Orbitrap, ions are trapped because their electrostatic attraction to the inner electrode is balanced by their inertia. Thus, ions cycle around the inner electrode on elliptical trajectories. In addition, the ions also move back and forth along the axis of the central electrode so that their trajectories in space resemble helices. Due to the properties of the quadro-logarithmic potential, their axial motion is harmonic, i.e. it is completely independent not only of motion around the inner electrode but also of all initial parameters of the ions except their mass-to-charge ratios m/z. Its angular frequency is: ω = , where k is the force constant of the potential, similar to the spring constant.
Injection
In order to inject ions from an external ion source, the f
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https://en.wikipedia.org/wiki/Efferent%20coupling
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Efferent coupling is a coupling metric in software development. It measures the number of data types a class knows about.
This includes inheritance, interface implementation, parameter types, variable types, and exceptions.
This has also been referred to by Robert C. Martin as the Fan-out stability metric which in his book Clean Architecture he describes as Outgoing dependencies. This metric identifies the number of classes inside this component that depend on classes outside the component.
This metric is often used to calculate instability of a component in software architecture as I = Fan-out / (Fan-in + Fan-out). This metric has a range [0,1]. I = 0 is maximally stable while I = 1 is maximally unstable.
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https://en.wikipedia.org/wiki/University%20of%20New%20Hampshire%20InterOperability%20Laboratory
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The University of New Hampshire InterOperability Laboratory (UNH-IOL) is an independent test facility that provides interoperability and standards conformance testing for networking, telecommunications, data storage, and consumer technology products.
Founded in 1988, it employs approximately 25 full-time staff members and over 100 part-time undergraduate and graduate students, and counts over 150 companies as members.
History
The UNH-IOL began as a project of the University's Research Computing Center (RCC). In 1988 the RCC was testing Fiber Distributed Data Interface (FDDI) equipment with the intention of deploying it in its network. The RCC found that equipment from two vendors did not work together and contacted the vendors to find a solution. The two vendors cooperated with the RCC to solve the problem which was caused by differences between the draft and final FDDI specification. During this same time period the RCC was testing 10BASE-T Ethernet interfaces for another project.
The University recognized the need for interoperability testing of networking equipment and also the opportunity to provide students with hands-on experience in emerging technologies. With the idea of providing testing services to companies in a vendor-neutral environment the first UNH-IOL consortium (10BASE-T Ethernet) was founded in 1990.
Over the next decade the UNH-IOL grew to twelve consortia with over 100 member companies. In 2002, having outgrown several smaller locations, the UNH-IOL moved to a 32,000 square foot facility on the outskirts of the UNH campus.
One area in which the UNH-IOL has been influential is IPv6 standardization and deployment. Between 2003 and 2007 the UNH-IOL organized the Moonv6 project, which was a multi-site, IPv6 based network designed to test the interoperability of IPv6 implementations. At the time the Moonv6 project was the largest permanently deployed multi-vendor IPv6 network in the world. The UNH-IOL is also the only North American laboratory of
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https://en.wikipedia.org/wiki/Alpha-1%20adrenergic%20receptor
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alpha-1 (α1) adrenergic receptors are G protein-coupled receptors (GPCRs) associated with the Gq heterotrimeric G protein. α1-adrenergic receptors are subdivided into three highly homologous subtypes, i.e., α1A-, α1B-, and α1D-adrenergic receptor subtypes. There is no α1C receptor. At one time, there was a subtype known as α1C, but it was found to be identical to the previously discovered α1A receptor subtype. To avoid confusion, naming was continued with the letter D. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α1-adrenergic receptors in the central and peripheral nervous systems. The crystal structure of the α1B-adrenergic receptor subtype has been determined in complex with the inverse agonist (+)-cyclazosin.
Effects
The α1-adrenergic receptor has several general functions in common with the α2-adrenergic receptor, but also has specific effects of its own. α1-receptors primarily mediate smooth muscle contraction, but have important functions elsewhere as well. The neurotransmitter norepinephrine has higher affinity for the α1 receptor than does the hormone adrenaline.
Smooth muscle
In smooth muscle cells of blood vessels the principal effect of activation of these receptors is vasoconstriction. Blood vessels with α1-adrenergic receptors are present in the skin, the sphincters of gastrointestinal system, kidney (renal artery) and brain. During the fight-or-flight response vasoconstriction results in decreased blood flow to these organs. This accounts for the pale appearance of the skin of an individual when frightened.
It also induces contraction of the internal urethral sphincter of the urinary bladder, although this effect is minor compared to the relaxing effect of β2-adrenergic receptors. In other words, the overall effect of sympathetic stimuli on the bladder is relaxation, in order to inhibit micturition upon anticipation of a stressful event. Other effects on smooth muscle are contraction in:
Urete
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https://en.wikipedia.org/wiki/Alpha-2%20adrenergic%20receptor
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The alpha-2 (α2) adrenergic receptor (or adrenoceptor) is a G protein-coupled receptor (GPCR) associated with the Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-, α2B-, and α2C-adrenergic. Some species other than humans express a fourth α2D-adrenergic receptor as well. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α2-adrenergic receptor in the central and peripheral nervous systems.
Cellular localization
The α2A adrenergic receptor is localised in the following central nervous system (CNS) structures:
Brainstem (especially the locus coeruleus as presynaptic & somatodendritic autoreceptor )
Midbrain
Hypothalamus
Olfactory system
Hippocampus
Spinal cord
Cerebral cortex
Cerebellum
Septum
Whereas the α2B adrenergic receptor is localised in the following CNS structures:
Thalamus
Pyramidal layer of the hippocampus
Cerebellar Purkinje layer
and the α2C adrenergic receptor is localised in the CNS structures:
Midbrain
Thalamus
Amygdala
Dorsal root ganglia
Olfactory system
Hippocampus
Cerebral cortex
Basal ganglia
Substantia nigra
Ventral tegmentum
Effects
The α2-adrenergic receptor is classically located on vascular prejunctional terminals where it inhibits the release of norepinephrine (noradrenaline) in a form of negative feedback. It is also located on the vascular smooth muscle cells of certain blood vessels, such as those found in skin arterioles or on veins, where it sits alongside the more plentiful α1-adrenergic receptor. The α2-adrenergic receptor binds both norepinephrine released by sympathetic postganglionic fibers and epinephrine (adrenaline) released by the adrenal medulla, binding norepinephrine with slightly higher affinity. It has several general functions in common with the α1-adrenergic receptor, but also has specific effects of its own. Agonists (activators) of the α2-adrenergic receptor are frequently used in anaesthesia where
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https://en.wikipedia.org/wiki/Paratope
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In immunology, a paratope, also known as an antigen-binding site, is the part of an antibody which recognizes and binds to an antigen. It is a small region at the tip of the antibody's antigen-binding fragment and contains parts of the antibody's heavy and light chains. Each paratope is made up of six complementarity-determining regions - three from each of the light and heavy chains - that extend from a fold of anti-parallel beta sheets. Each arm of the Y-shaped antibody has an identical paratope at the end.
Paratopes make up the parts of the B-cell receptor that bind to and make contact with the epitope of an antigen. All the B-cell receptors on any one individual B cell have identical paratopes. The uniqueness of a paratope allows it to bind to only one epitope with high affinity and as a result, each B cell can only respond to one epitope. The paratopes on B-cell receptors binding to their specific epitope is a critical step in the adaptive immune response.
Design of paratopes between species
The design and structure of paratopes can differ greatly between different species. In jawed-vertebrates, V(D)J recombination can result in billions of different paratopes. The number of paratopes, however, is limited by the composition of the V, D, and J genes and the structure of the antibody. Thus, many different species have developed ways to bypass this restriction and increase the diversity of possible paratopes.
In cows, an extra-long complementarity-determining region is considered to have an essential role in diversifying paratopes. Additionally, both chickens and rabbits use gene conversion to increase the number of paratopes that are possible.
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https://en.wikipedia.org/wiki/Levator%20muscle%20of%20thyroid%20gland
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A fibrous or muscular band is sometimes found attached, above, to the body of the hyoid bone, and below to the thyroid isthmus, or its pyramidal lobe. When muscular, it is termed the Levator muscle of thyroid gland.
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https://en.wikipedia.org/wiki/Rose%20%28heraldry%29
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The rose is a common device in heraldry. It is often used both as a charge on a coat of arms and by itself as an heraldic badge. The heraldic rose has a stylized form consisting of five symmetrical lobes, five barbs, and a circular seed. The rose is one of the most common plant symbols in heraldry, together with the lily, which also has a stylistic representation in the fleur-de-lis.
The rose was the symbol of the English Tudor dynasty, and the ten-petaled Tudor rose (termed a double rose) is associated with England. Roses also feature prominently in the arms of the princely House of Lippe and on the seal of Martin Luther.
Appearance
The normal appearance of the heraldic rose is a five-petaled rose, mimicking the look of a wild rose on a hedgerow. It is shown singly and full-faced. It most commonly has yellow seeds in the center and five green barbs as backing; such a rose is blazoned as barbed and seeded proper. If the seeds and barbs are of a different colour, then the rose is barbed and seeded of that/those tinctures. The rose of Lippe shown below, for example, is blazoned a Rose Gules, barbed and seeded Or.
Some variations on the rose have been used. Roses may appear with a stem, in which case they are described as slipped or stalked. A rose with a stalk and leaves may also be referred to as a damask rose, stalked and leaved, as appearing on the Canting arms of the House of Rossetti.
Rose branches, slips, and leaves have occasionally appeared in arms alone, without the flower. A combination of two roses, one within the other, is termed a double rose, famously used by the Tudors.
A rose sometimes appears surrounded by rays, which makes it a rose-en-soleil (rose in the sun). A rose may be crowned. Roses may appear within a chaplet, a garland of leaves with four flowers. In badges, it is not uncommon for a rose to be conjoined with another device. Catherine of Aragon's famous badge was a pomegranate conjoined with the double rose of her husband, Henry VI
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https://en.wikipedia.org/wiki/Apollonian%20circles
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In geometry, Apollonian circles are two families (pencils) of circles such that every circle in the first family intersects every circle in the second family orthogonally, and vice versa. These circles form the basis for bipolar coordinates. They were discovered by Apollonius of Perga, a renowned Greek geometer.
Definition
The Apollonian circles are defined in two different ways by a line segment denoted .
Each circle in the first family (the blue circles in the figure) is associated with a positive real number , and is defined as the locus of points such that the ratio of distances from to and to equals ,
For values of close to zero, the corresponding circle is close to , while for values of close to , the corresponding circle is close to ; for the intermediate value , the circle degenerates to a line, the perpendicular bisector of . The equation defining these circles as a locus can be generalized to define the Fermat–Apollonius circles of larger sets of weighted points.
Each circle in the second family (the red circles in the figure) is associated with an angle , and is defined as the locus of points such that the inscribed angle equals ,
Scanning from 0 to π generates the set of all circles passing through the two points and .
The two points where all the red circles cross are the limiting points of pairs of circles in the blue family.
Bipolar coordinates
A given blue circle and a given red circle intersect in two points. In order to obtain bipolar coordinates, a method is required to specify which point is the right one. An isoptic arc is the locus of points that sees points under a given oriented angle of vectors i.e.
Such an arc is contained into a red circle and is bounded by points . The remaining part of the corresponding red circle is . When we really want the whole red circle, a description using oriented angles of straight lines has to be used:
Pencils of circles
Both of the families of Apollonian circles are pencils of circles.
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https://en.wikipedia.org/wiki/Laryngeal%20vestibule
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The portion of the cavity of the larynx above the vestibular fold is called the laryngeal vestibule; it is wide and triangular in shape, its base or anterior wall presenting, however, about its center the backward projection of the tubercle of the epiglottis. It contains the vestibular folds, and between these and the vocal folds are the laryngeal ventricles.
The vestibule is an opening in the lateral wall of the larynx, between the vestibular fold above and the vocal folds below. It is the inlet to another cavity in the lateral wall of larynx, the laryngeal ventricle. The vestibular fold is formed by the vestibular ligament extending from the lateral walls of the epiglottis to the arytenoid cartilage covered with mucous membrane. The vocal fold is the upper free margin of the conus elasticus which is covered by mucous membrane. The conus elasticus or lateral ligament is the lateral thickened part of the cricothyroid membrane.
Additional images
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https://en.wikipedia.org/wiki/257-gon
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In Geometry, 257-gon, also known broadly as the Dihectapentacontakaiheptagon, is a polygon with 257 sides. The sum of the interior angles of any non-self-intersecting 257-gon is 45,900°.
Regular 257-gon
The area of a regular 257-gon is (with )
A whole regular 257-gon is not visually discernible from a circle, and its perimeter differs from that of the circumscribed circle by about 24 parts per million.
Construction
The regular 257-gon (one with all sides equal and all angles equal) is of interest for being a constructible polygon: that is, it can be constructed using a compass and an unmarked straightedge. This is because 257 is a Fermat prime, being of the form 22n + 1 (in this case n = 3). Thus, the values and are 128-degree algebraic numbers, and like all constructible numbers they can be written using square roots and no higher-order roots.
Although it was known to Gauss by 1801 that the regular 257-gon was constructible, the first explicit constructions of a regular 257-gon were given by Magnus Georg Paucker (1822) and Friedrich Julius Richelot (1832). Another method involves the use of 150 circles, 24 being Carlyle circles: this method is pictured below. One of these Carlyle circles solves the quadratic equation x2 + x − 64 = 0.
Symmetry
The regular 257-gon has Dih257 symmetry, order 514. Since 257 is a prime number there is one subgroup with dihedral symmetry: Dih1, and 2 cyclic group symmetries: Z257, and Z1.
257-gram
A 257-gram is a 257-sided star polygon. As 257 is prime, there are 127 regular forms generated by Schläfli symbols {257/n} for all integers 2 ≤ n ≤ 128 as .
Below is a view of {257/128}, with 257 nearly radial edges, with its star vertex internal angles 180°/257 (~0.7°).
See also
17-gon
List of polygons
List of self-intersecting polygons
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https://en.wikipedia.org/wiki/65537-gon
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In geometry, a 65537-gon is a polygon with 65,537 (216 + 1) sides. The sum of the interior angles of any non–self-intersecting is 11796300°.
Regular 65537-gon
The area of a regular is (with )
A whole regular is not visually discernible from a circle, and its perimeter differs from that of the circumscribed circle by about 15 parts per billion.
Construction
The regular 65537-gon (one with all sides equal and all angles equal) is of interest for being a constructible polygon: that is, it can be constructed using a compass and an unmarked straightedge. This is because 65,537 is a Fermat prime, being of the form 22n + 1 (in this case n = 4).
Thus, the values and are 32768-degree algebraic numbers, and like any constructible numbers, they can be written in terms of square roots and no higher-order roots.
Although it was known to Gauss by 1801 that the regular 65537-gon was constructible, the first explicit construction of a regular 65537-gon was given by Johann Gustav Hermes (1894). The construction is very complex; Hermes spent 10 years completing the 200-page manuscript. Another method involves the use of at most 1332 Carlyle circles, and the first stages of this method are pictured below. This method faces practical problems, as one of these Carlyle circles solves the quadratic equation x2 + x − 16384 = 0 (16384 being 214).
Symmetry
The regular 65537-gon has Dih65537 symmetry, order 131074. Since 65,537 is a prime number there is one subgroup with dihedral symmetry: Dih1, and 2 cyclic group symmetries: Z65537, and Z1.
65537-gram
A 65537-gram is a 65,537-sided star polygon. As 65,537 is prime, there are 32,767 regular forms generated by Schläfli symbols {65537/n} for all integers 2 ≤ n ≤ 32768 as .
See also
Circle
Equilateral triangle
Pentagon
Heptadecagon (17-sides)
257-gon
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https://en.wikipedia.org/wiki/Corniculate%20cartilages
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The corniculate cartilages (cartilages of Santorini) are two small conical nodules consisting of elastic cartilage, which articulate with the summits of the arytenoid cartilages and serve to prolong them posteriorly and medially.
They are situated in the posterior parts of the aryepiglottic folds of mucous membrane, and are sometimes fused with the arytenoid cartilages.
Eponym
It is named by Giovanni Domenico Santorini. The word "Corniculate" has a Latin root "cornu". Cornu means horn like projections. The projections of Corniculate cartilage look like "horns" hence the name.
Additional images
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https://en.wikipedia.org/wiki/Aryepiglottic%20fold
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The aryepiglottic folds are triangular folds of mucous membrane of the larynx. They enclose ligamentous and muscular fibres. They extend from the lateral borders of the epiglottis to the arytenoid cartilages, hence the name 'aryepiglottic'. They contain the aryepiglottic muscles and form the upper borders of the quadrangular membrane. They have a role in growling as a form of phonation. They may be narrowed and cause stridor, or be shortened and cause laryngomalacia.
Structure
The aryepiglottic folds are triangular. They are narrow in front, wide behind, and slope obliquely downward and backward. They originate from the lateral borders of the epiglottis. They insert into the arytenoid cartilages.
In front, they are bounded by the epiglottis. Behind, they are bounded by the apices of the arytenoid cartilages, the corniculate cartilages, and the interarytenoid notch. Within the posterior part of each aryepiglottic fold exists a cuneiform cartilage which forms a whitish prominence, the cuneiform tubercle.
The aryepiglottic folds contain the aryepiglottic muscles. They form the upper borders of the quadrangular membrane, and the lateral borders of the laryngeal inlet.
Function
Phonation
Under certain circumstances, the aryepiglottic folds take part in phonation, for instance in the singing technique of vocal growl, such as practiced by Louis Armstrong and other jazz singers. The approximation of the aryepiglottic folds during vocalization may establish sustained co-oscillations, at relatively low frequencies, producing the growl or growling effect.
Clinical significance
Stridor
If the aryepiglottic folds narrow the laryngeal inlet, they may cause stridor.
Laryngomalacia
The aryepiglottic folds are shortened in laryngomalacia. They may be surgically removed to prevent problems eating and shortness of breath.
Gallery
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https://en.wikipedia.org/wiki/Immune%20tolerance
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Immune tolerance, or immunological tolerance, or immunotolerance, is a state of unresponsiveness of the immune system to substances or tissue that would otherwise have the capacity to elicit an immune response in a given organism. It is induced by prior exposure to that specific antigen and contrasts with conventional immune-mediated elimination of foreign antigens (see Immune response). Tolerance is classified into central tolerance or peripheral tolerance depending on where the state is originally induced—in the thymus and bone marrow (central) or in other tissues and lymph nodes (peripheral). The mechanisms by which these forms of tolerance are established are distinct, but the resulting effect is similar.
Immune tolerance is important for normal physiology. Central tolerance is the main way the immune system learns to discriminate self from non-self. Peripheral tolerance is key to preventing over-reactivity of the immune system to various environmental entities (allergens, gut microbes, etc.). Deficits in central or peripheral tolerance also cause autoimmune disease, resulting in syndromes such as systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, autoimmune polyendocrine syndrome type 1 (APS-1), and immunodysregulation polyendocrinopathy enteropathy X-linked syndrome (IPEX), and potentially contribute to asthma, allergy, and inflammatory bowel disease. And immune tolerance in pregnancy is what allows a mother animal to gestate a genetically distinct offspring with an alloimmune response muted enough to prevent miscarriage.
Tolerance, however, also has its negative tradeoffs. It allows for some pathogenic microbes to successfully infect a host and avoid elimination. In addition, inducing peripheral tolerance in the local microenvironment is a common survival strategy for a number of tumors that prevents their elimination by the host immune system.
Historical background
The phenomenon of immune tolerance was first described by Ray D. Owen
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https://en.wikipedia.org/wiki/Cloacal%20membrane
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The cloacal membrane is the membrane that covers the embryonic cloaca during the development of the urinary and reproductive organs.
It is formed by ectoderm and endoderm coming into contact with each other. As the human embryo grows and caudal folding continues, the urorectal septum divides the cloaca into a ventral urogenital sinus and dorsal anorectal canal. Before the urorectal septum has an opportunity to fuse with the cloacal membrane, the membrane ruptures, exposing the urogenital sinus and dorsal anorectal canal to the exterior. Later on, an ectodermal plug, the anal membrane, forms to create the lower third of the rectum. It ruptures in the seventh week of gestation.
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https://en.wikipedia.org/wiki/Septum%20primum
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During heart development of a human embryo, the single primitive atrium becomes divided into right and left by a , the septum primum. The septum primum () grows downward into the single atrium.
Development
The gap below it is known as the ostium primum (), and becomes increasingly small. The septum primum eventually fuses with the endocardial cushion, closing the ostium primum off completely. Meanwhile, perforations appear in the superior part of the septum primum, forming the ostium secundum (). The septum primum will eventually form part of the fossa ovalis. Blood flow between atria will continue through the foramen ovale (heart).
Clinical significance
Failure of the septum primum to fuse with the endocardial cushion can lead to an ostium primum atrial septal defect. This is the second most common type of atrial septal defect and is commonly seen in Down syndrome. Typically this defect will cause a shunt to occur from the left atrium to the right atrium. Children born with this defect may be asymptomatic, however, over time pulmonary hypertension and the resulting hypertrophy of the right side of the heart will lead to a reversal of this shunt. This reversal is called Eisenmenger's syndrome.
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https://en.wikipedia.org/wiki/Optic%20cup%20%28embryology%29
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During embryonic development of the eye, the outer wall of the bulb of the optic vesicles becomes thickened and invaginated, and the bulb is thus converted into a cup, the optic cup (or ophthalmic cup), consisting of two strata of cells. These two strata are continuous with each other at the cup margin, which ultimately overlaps the front of the lens and reaches as far forward as the future aperture of the pupil.
The optic cup is part of the diencephalon and gives rise to the retina of the eye.
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https://en.wikipedia.org/wiki/Septum%20secundum
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The septum secundum is a muscular flap that is important in heart development. It is semilunar in shape, and grows downward from the upper wall of the atrium immediately to the right of the septum primum and ostium secundum. It is important in the closure of the foramen ovale after birth.
Structure
Development
At the end of the fifth week of development, the septum secundum grows from the upper wall of the primitive atrium. It grows to the right of the septum primum, which has already started growing. It grows down towards the septum intermedium formed from the endocardial cushions. Before birth, it does not fuse with the septum intermedium, leaving a gap to form the foramen ovale. Shortly after birth, it fuses with the septum primum to form the interatrial septum, and the foramen ovale is closed. The fossa ovalis denotes the free margin of the septum secundum after birth.
Clinical significance
Sometimes, the fusion of the septum secundum to the septum intermedium is incomplete, and the upper part of the foramen remains patent. This creates an atrial septal defect (ASD).
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https://en.wikipedia.org/wiki/Macdonald%20identities
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In mathematics, the Macdonald identities are some infinite product identities associated to affine root systems, introduced by . They include as special cases the Jacobi triple product identity, Watson's quintuple product identity, several identities found by , and a 10-fold product identity found by .
and pointed out that the Macdonald identities are the analogs of the Weyl denominator formula for affine Kac–Moody algebras and superalgebras.
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https://en.wikipedia.org/wiki/Sour%20sanding
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Sour sanding, or sour sugar, is a food ingredient that is used to impart a sour flavor, made from citric or tartaric acid and sugar. It is used to coat sour candies such as lemon drops and Sour Patch Kids, or to make hard candies taste tart, such as SweeTarts.
See also
Acidulant
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https://en.wikipedia.org/wiki/Paris%27%20law
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Paris' law (also known as the Paris–Erdogan equation) is a crack growth equation that gives the rate of growth of a fatigue crack. The stress intensity factor characterises the load around a crack tip and the rate of crack growth is experimentally shown to be a function of the range of stress intensity seen in a loading cycle. The Paris equation is
where is the crack length and is the fatigue crack growth for a load cycle . The material coefficients and are obtained experimentally and also depend on environment, frequency, temperature and stress ratio. The stress intensity factor range has been found to correlate the rate of crack growth from a variety of different conditions and is the difference between the maximum and minimum stress intensity factors in a load cycle and is defined as
Being a power law relationship between the crack growth rate during cyclic loading and the range of the stress intensity factor, the Paris–Erdogan equation can be visualized as a straight line on a log-log plot, where the x-axis is denoted by the range of the stress intensity factor and the y-axis is denoted by the crack growth rate.
The ability of ΔK to correlate crack growth rate data depends to a large extent on the fact that alternating stresses causing crack growth are small compared to the yield strength. Therefore crack tip plastic zones are small compared to crack length even in very ductile materials like stainless steels.
The equation gives the growth for a single cycle. Single cycles can be readily counted for constant-amplitude loading. Additional cycle identification techniques such as rainflow-counting algorithm need to be used to extract the equivalent constant-amplitude cycles from a variable-amplitude loading sequence.
History
In a 1961 paper, P. C. Paris introduced the idea that the rate of crack growth may depend on the stress intensity factor. Then in their 1963 paper, Paris and Erdogan indirectly suggested the equation with the aside remark "
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https://en.wikipedia.org/wiki/Suslin%20tree
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In mathematics, a Suslin tree is a tree of height ω1 such that
every branch and every antichain is at most countable. They are named after Mikhail Yakovlevich Suslin.
Every Suslin tree is an Aronszajn tree.
The existence of a Suslin tree is independent of ZFC, and is equivalent to the existence of a Suslin line (shown by ) or a Suslin algebra. The diamond principle, a consequence of V=L, implies that there is a Suslin tree, and Martin's axiom MA(ℵ1) implies that there are no Suslin trees.
More generally, for any infinite cardinal κ, a κ-Suslin tree is a tree of height κ such that every branch and antichain has cardinality less than κ. In particular a Suslin tree is the same as a ω1-Suslin tree. showed that if V=L then there is a κ-Suslin tree for every infinite successor cardinal κ. Whether the Generalized Continuum Hypothesis implies the existence of an ℵ2-Suslin tree, is a longstanding open problem.
See also
Glossary of set theory
Kurepa tree
List of statements independent of ZFC
List of unsolved problems in set theory
Suslin's problem
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https://en.wikipedia.org/wiki/Sergei%20Adian
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Sergei Ivanovich Adian, also Adyan (; ; 1 January 1931 – 5 May 2020), was a Soviet and Armenian mathematician. He was a professor at the Moscow State University and was known for his work in group theory, especially on the Burnside problem.
Biography
Adian was born near Elizavetpol. He grew up there in an Armenian family. He studied at Yerevan and Moscow pedagogical institutes. His advisor was Pyotr Novikov. He worked at Moscow State University (MSU) since 1965. Alexander Razborov was one of his students.
Mathematical career
In his first work as a student in 1950, Adian proved that the graph of a function of a real variable satisfying the functional equation and having discontinuities is dense in the plane. (Clearly, all continuous solutions of the equation are linear functions.) This result was not published at the time. About 25 years later the American mathematician Edwin Hewitt from the University of Washington gave preprints of some of his papers to Adian during a visit to MSU, one of which was devoted to exactly the same result, which was published by Hewitt much later.
By the beginning of 1955, Adian had managed to prove the undecidability of practically all non-trivial invariant group properties, including the undecidability of being isomorphic to a fixed group , for any group . These results constituted his Ph.D. thesis and his first published work. This is one of the most remarkable, beautiful, and general results in algorithmic group theory and is now known as the Adian–Rabin theorem. What distinguishes the first published work by Adian, is its completeness. In spite of numerous attempts, nobody has added anything fundamentally new to the results during the past 50 years. Adian's result was immediately used by Andrey Markov Jr. in his proof of the algorithmic unsolvability of the classical problem of deciding when topological manifolds are homeomorphic.
Burnside problem
About the Burnside problem:
Very much like Fermat's Last Theorem in number theor
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https://en.wikipedia.org/wiki/Blackdamp
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Blackdamp (also known as stythe or choke damp) is an asphyxiant, reducing the available oxygen content of air to a level incapable of sustaining human or animal life. It is not a single gas but a mixture of unbreathable gases left after oxygen is removed from the air and typically consists of nitrogen, carbon dioxide and water vapour. The term is etymologically and practically related to terms for other underground mine gases such as fire damp, white damp, stink damp, and afterdamp.
Etymology
The meaning of "damp" in this term, while most commonly understood to imply humidity, presents evidence of having been separated from that newer, irrelevant meaning at least by the first decade of the 18th century, where the original relevant meaning of "vapor" derives from a Proto-Germanic origin, dampaz, which gave rise to its immediate English predecessor, the Middle Low German damp (with no record of an Old English intermediary). The proto-Germanic dampaz gave rise to many other cognates, including the Old High German damph, the Old Norse dampi, and the modern German Dampf, the last of which still translates as "vapor".
Sources
Blackdamp is encountered in enclosed environments such as mines, sewers, wells, tunnels and ships' holds. It occurs with particular frequency in abandoned or poorly ventilated coal mines. Coal, once exposed to the air of a mine, naturally begins absorbing oxygen and exuding carbon dioxide and water vapor. The amount of blackdamp exuded by a mine varies based on a number of factors, including the temperature (coal releases more carbon dioxide in the warmer months), the amount of exposed coal, and the type of coal, although all mines with exposed coal produce gas.
Hazards
Blackdamp is considered a particularly pernicious type of damp (especially in a historical context), due to its omnipresence where exposed coal is found, and slow onset of symptoms. It produces no obvious odor (unlike the hydrogen sulfide of stinkdamp), is constantly being reintro
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https://en.wikipedia.org/wiki/The%20Eleventh%20Hour%20%28book%29
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The Eleventh Hour: A Curious Mystery is an illustrated children's book by Graeme Base. In it, Horace the Elephant holds a party for his eleventh birthday, to which he invites his ten best friends (various animals) to play eleven games and share in a feast that he has prepared. However, at the time they are to eat—11:00—they are startled to find that someone has already eaten all the food. They accuse each other until, finally, they're left puzzled as to who could have eaten it all. It is left up to the reader to solve the mystery, through careful analysis of the pictures on each page and the words in the story.
The book was a joint-winner of the "Picture Book of the Year" award from The Children's Book Council of Australia.
History
Base was inspired to write the book by reading Agatha Christie novels. He travelled to Kenya and Tanzania in 1987 observing animals in game parks and collecting ideas for the book.
Style
Written in rhyme, the book includes large and lavish full-page illustrations of Horace's opulent house and the events of the party, packed with hidden details. The author invites the reader to deduce the identity of the thief by examining the illustrations and making deductions and observations. Also among the details in the illustrations are hidden messages, ciphers, and codes for amateur cryptographers (for example, one page's border consists of Morse code while another page set in the ballroom contains musical clues as to which guest is guilty). The biggest and most noticeable clue lies in a paragraph of ciphertext at the end of the book, which is to be decrypted, once the reader has discovered the identity of the thief, by means of a Caesar cipher mapping A to the first letter of the guilty animal's name. The solution to the cipher confirms the answer to the puzzle and offers an additional challenge to the reader.
The final portion of the book contains the answers to almost all of the clues in the book (including the cipher), and how to solve the
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https://en.wikipedia.org/wiki/Atlanto-occipital%20joint
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The atlanto-occipital joint (Capsula articularis atlantooccipitalis) is an articulation between the atlas bone and the occipital bone. It consists of a pair of condyloid joints. It is a synovial joint.
Structure
The atlanto-occipital joint is an articulation between the atlas bone and the occipital bone. It consists of a pair of condyloid joints. It is a synovial joint.
Ligaments
The ligaments connecting the bones are:
Two articular capsules
Posterior atlanto-occipital membrane
Anterior atlanto-occipital membrane
Capsule
The capsules of the atlantooccipital articulation surround the condyles of the occipital bone, and connect them with the articular processes of the atlas: they are thin and loose.
Function
The movements permitted in this joint are:
(a) flexion and extension around the mediolateral axis, which give rise to the ordinary forward and backward nodding of the head.
(b) slight lateral motion, lateroflexion, to one or other side around the anteroposterior axis.
Flexion is produced mainly by the action of the longi capitis and recti capitis anteriores; extension by the recti capitis posteriores major and minor, the obliquus capitis superior, the semispinalis capitis, splenius capitis, sternocleidomastoideus, and upper fibers of the trapezius.
The recti laterales are concerned in the lateral movement, assisted by the trapezius, splenius capitis, semispinalis capitis, and the sternocleidomastoideus of the same side, all acting together.
Clinical significance
Dislocation
The atlanto-occipital joint may be dislocated, especially from violent accidents such as traffic collisions. This may be diagnosed using CT scans or magnetic resonance imaging of the head and neck. Surgery may be used to fix the joint and any associated bone fractures. Neck movement may be reduced long after this injury. Such injuries may also lead to hypermobility, which may be diagnosed with radiographs. This is especially true if traction is used during treatment.
Additional
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https://en.wikipedia.org/wiki/Waveform%20buffer
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In computing, a waveform buffer is a technique for digital synthesis of repeating waveforms. It is common in PC sound cards.
The waveform amplitude values are stored in a buffer memory, which is addressed from a phase generator, with the retrieved value then used as the basis of the synthesized signal. In the phase generator, a value proportional to the desired signal frequence is periodically added to an accumulator. The high order bits of the accumulator form the output address, while the typically larger number of bits in the accumulator and addition value results in an arbitrarily high frequency resolution.
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https://en.wikipedia.org/wiki/Action%20selection
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Action selection is a way of characterizing the most basic problem of intelligent systems: what to do next. In artificial intelligence and computational cognitive science, "the action selection problem" is typically associated with intelligent agents and animats—artificial systems that exhibit complex behaviour in an agent environment. The term is also sometimes used in ethology or animal behavior.
One problem for understanding action selection is determining the level of abstraction used for specifying an "act". At the most basic level of abstraction, an atomic act could be anything from contracting a muscle cell to provoking a war. Typically for any one action-selection mechanism, the set of possible actions is predefined and fixed.
Most researchers working in this field place high demands on their agents:
The acting agent typically must select its action in dynamic and unpredictable environments.
The agents typically act in real time; therefore they must make decisions in a timely fashion.
The agents are normally created to perform several different tasks. These tasks may conflict for resource allocation (e.g. can the agent put out a fire and deliver a cup of coffee at the same time?)
The environment the agents operate in may include humans, who may make things more difficult for the agent (either intentionally or by attempting to assist.)
The agents themselves are often intended to model animals or humans, and animal/human behaviour is quite complicated.
For these reasons action selection is not trivial and attracts a good deal of research.
Characteristics of the action selection problem
The main problem for action selection is complexity. Since all computation takes both time and space (in memory), agents cannot possibly consider every option available to them at every instant in time. Consequently, they must be biased, and constrain their search in some way. For AI, the question of action selection is what is the best way to constrain this search? Fo
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https://en.wikipedia.org/wiki/American%20Institute%20of%20Biological%20Sciences
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The American Institute of Biological Sciences (AIBS) is a nonprofit scientific public charitable organization. The organization's mission is to promote the use of science to inform decision-making and advance biology for the benefit of science and society.
Overview
AIBS serves as a society of societies. AIBS has over 115 member organizations and is headquartered in Herndon, VA. Its staff work to achieve its mission by publishing the peer-reviewed journal BioScience, providing peer review and advisory support services for funding organizations, providing professional development for scientists and students, advocating for science policy and educating the public about biology. AIBS works with like-minded organizations, funding agencies, and nonprofit and for-profit entities to promote the use of science to inform decision-making.
AIBS is governed by an esteemed Board of Directors and a Council of representatives of our member organizations.
Background and history
AIBS was established in 1947 as a part of the National Academy of Sciences. The overarching goal was to unify the individuals and organizations that collectively represent the biological sciences, so that the community could address matters of common concern. In the 1950s, AIBS became an independent, member-governed, nonprofit 501(c)3 public charity scientific organization. The organization continues to work diligently to communicate biology to the scientific community, funders, policymakers, and other groups interested in exploring cross-cutting ideas in the biological sciences
Strategic priorities
AIBS works toward overarching outcomes through three strategic priorities:
Scientific Peer Advisory and Review Services for research proposals and programs sponsored by funding organizations, including the federal government, state agencies, private research foundations, other non-government organizations and educate the community about the science of peer review.
Publications and Communica
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https://en.wikipedia.org/wiki/Reactive%20planning
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In artificial intelligence, reactive planning denotes a group of techniques for action selection by autonomous agents. These techniques differ from classical planning in two aspects. First, they operate in a timely fashion and hence can cope with highly dynamic and unpredictable environments. Second, they compute just one next action in every instant, based on the current context. Reactive planners often (but not always) exploit reactive plans, which are stored structures describing the agent's priorities and behaviour. The term reactive planning goes back to at least 1988, and is synonymous with the more modern term dynamic planning.
Reactive plan representation
There are several ways to represent a reactive plan. All require a basic representational unit and a means to compose these units into plans.
Condition-action rules (productions)
A condition action rule, or if-then rule, is a rule in the form: if condition then action. These rules are called productions. The meaning of the rule is as follows: if the condition holds, perform the action. The action can be either external (e.g., pick something up and move it), or internal (e.g., write a fact into the internal memory, or evaluate a new set of rules). Conditions are normally boolean and the action either can be performed, or not.
Production rules may be organized in relatively flat structures, but more often are organized into a hierarchy of some kind. For example, subsumption architecture consists of layers of interconnected behaviors, each actually a finite state machine which acts in response to an appropriate input. These layers are then organized into a simple stack, with higher layers subsuming the goals of the lower ones. Other systems may use trees, or may include special mechanisms for changing which goal / rule subset is currently most important. Flat structures are relatively easy to build, but allow only for description of simple behavior, or require immensely complicated conditions to
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https://en.wikipedia.org/wiki/Criticism%20of%20Wikipedia
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Most criticism of Wikipedia has been directed toward its content, community of established users, and processes. Critics have questioned its factual reliability, the readability and organization of the articles, the lack of methodical fact-checking, and its political bias. Concerns have also been raised about systemic bias along gender, racial, political, corporate, institutional, and national lines. In addition, conflicts of interest arising from corporate campaigns to influence content have also been highlighted. Further concerns include the vandalism and partisanship facilitated by anonymous editing, clique behavior (from contributors as well as administrators and other top figures), social stratification between a guardian class and newer users, excessive rule-making, edit warring, and uneven policy application.
Criticism of content
The reliability of Wikipedia is often questioned. In Wikipedia: The Dumbing Down of World Knowledge (2010), journalist Edwin Black characterized the content of articles as a mixture of "truth, half-truth, and some falsehoods". Oliver Kamm, in Wisdom?: More like Dumbness of the Crowds (2007), said that articles usually are dominated by the loudest and most persistent editorial voices or by an interest group with an ideological "axe to grind".
In his article The 'Undue Weight' of Truth on Wikipedia (2012), Timothy Messer–Kruse criticized the undue-weight policy that deals with the relative importance of sources, observing that it showed Wikipedia's goal was not to present correct and definitive information about a subject but to present the majority opinion of the sources cited. In their article You Just Type in What You are Looking for: Undergraduates' Use of Library Resources vs. Wikipedia (2012) in an academic librarianship journal, the authors noted another author's point that omissions within an article might give the reader false ideas about a topic, based upon the incomplete content of Wikipedia.
Wikipedia is sometimes charac
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https://en.wikipedia.org/wiki/Superficial%20epigastric%20artery
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The superficial epigastric artery (not to be confused with the superior epigastric artery) arises from the front of the femoral artery about 1 cm below the inguinal ligament, and, passing through the femoral sheath and the fascia cribrosa, turns upward in front of the inguinal ligament, and ascends between the two layers of the superficial fascia of the abdominal wall nearly as far as the umbilicus.
It distributes branches to the superficial subinguinal lymph glands, the superficial fascia, and the integument; it anastomoses with branches of the inferior epigastric, and with its fellow of the opposite side.
Additional images
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https://en.wikipedia.org/wiki/Tongue%20rolling
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Tongue rolling is the ability to roll the lateral edges of the tongue upwards into a tube. The tongue's intrinsic muscles allow some people to form their tongues into specific shapes. Rolling the tongue into a tube shape is often described as a dominant trait with simple Mendelian inheritance, and it is commonly referenced in introductory and genetic biology courses, although there is some disagreement.
Genetics
Prevalence in human populations varies between 65% and 81%.
There is no statistically significant sexual dimorphism in this trait. A 1940 study by Alfred Sturtevant analyzed 282 people of mostly European ancestry. and observed that 67.1% of females and 62.9% of males could roll their tongues, and the remaining could not do it. A 1980 study with 992 people also found similar percentages, in 66.84% of females and 63.7% of males possessing the ability.
In some cases, the ability can be learned by practice, more easily by children, but also by adults. For this reason, studies should allow time for individuals to learn this and other abilities. This also indicates that it's not a simple hereditary trait, and there are other factors involved.
In the first paper about this trait as a genetic trait, Sturtevant concluded that the ability "is conditioned at least in part by heredity", and suggests that "it is possible, though not proved, that ability to turn up the edges of the tongue may be due to a single dominant gene, with the fairly frequent occurrence of additional complications". These findings, however, have been questioned.
Several twin studies on the issue have been conducted. A 1952 study involving 33 pairs of identical twins found that 21% of them were discordant - that is, one of the twins had the ability and the other did not. A 1971 study found that identical twins were 18% discordant, and 22% of non-identical twins were discordant, concluding that "hereditary factors strongly influences tongue rolling ability". However, a 1975 found that identica
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https://en.wikipedia.org/wiki/Chipkill
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Chipkill is IBM's trademark for a form of advanced error checking and correcting (ECC) computer memory technology that protects computer memory systems from any single memory chip failure as well as multi-bit errors from any portion of a single memory chip. One simple scheme to perform this function scatters the bits of a Hamming code ECC word across multiple memory chips, such that the failure of any single memory chip will affect only one ECC bit per word. This allows memory contents to be reconstructed despite the complete failure of one chip. Typical implementations use more advanced codes, such as a BCH code, that can correct multiple bits with less overhead.
Chipkill is frequently combined with dynamic bit-steering, so that if a chip fails (or has exceeded a threshold of bit errors), another, spare, memory chip is used to replace the failed chip. The concept is similar to that of RAID, which protects against disk failure, except that now the concept is applied to individual memory chips. The technology was developed by the IBM Corporation in the early and middle 1990s. An important RAS feature, Chipkill technology is deployed primarily on SSDs, mainframes and midrange servers.
An equivalent system from Sun Microsystems is called Extended ECC, while equivalent systems from HP are called Advanced ECC and Chipspare. A similar system from Intel, called Lockstep memory, provides double-device data correction (DDDC) functionality. Similar systems from Micron, called redundant array of independent NAND (RAIN), and from SandForce, called RAISE level 2, protect data stored on SSDs from any single NAND flash chip going bad.
A 2009 paper using data from Google's datacentres provided evidence demonstrating that in observed Google systems, DRAM errors were recurrent at the same location, and that 8% of DIMMs were affected each year. Specifically, "In more than 85% of the cases a correctable error is followed by at least one more correctable error in the same month"
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https://en.wikipedia.org/wiki/Rhomboid%20fossa
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The rhomboid fossa is a rhombus-shaped depression that is the anterior part of the fourth ventricle. Its anterior wall, formed by the back of the pons and the medulla oblongata, constitutes the floor of the fourth ventricle.
It is covered by a thin layer of grey matter continuous with that of the spinal cord; superficial to this is a thin lamina of neuroglia which constitutes the ependyma of the ventricle and supports a layer of ciliated epithelium.
Parts
The fossa consists of three parts, superior, intermediate, and inferior:
The superior part
The superior part is triangular in shape and limited laterally by the superior cerebellar peduncle; its apex, directed upward, is continuous with the cerebral aqueduct; its base is represented by an imaginary line at the level of the upper ends of the superior foveae.
The intermediate part
The intermediate part extends from this level to that of the horizontal portions of the taeniae of the ventricle; it is narrow above where it is limited laterally by the middle peduncle, but widens below and is prolonged into the lateral recesses of the ventricle.
The inferior part
The inferior part is triangular, and its downwardly directed apex, named the calamus scriptorius (as is shaped like a writing quill-nib) is continuous with the central canal of the closed part of the medulla oblongata.
The sulcus limitans forms the lateral boundary of the medial eminence.
Features
In the superior part of the rhomboid fossa it corresponds with the lateral limit of the fossa and presents a bluish-gray area, the locus coeruleus, which owes its color to an underlying patch of deeply pigmented nerve cells, termed the substantia ferruginea.
At the level of the facial colliculus the sulcus limitans widens into a flattened depression, the superior fovea, and in the inferior part of the fossa appears as a distinct dimple, the inferior fovea.
Lateral to the foveæ is a rounded elevation named the area acustica, which extends into the lateral recess
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https://en.wikipedia.org/wiki/Linkwitz%E2%80%93Riley%20filter
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A Linkwitz–Riley (L-R) filter is an infinite impulse response filter used in Linkwitz–Riley audio crossovers, named after its inventors Siegfried Linkwitz and Russ Riley. This filter type was originally described in Active Crossover Networks for Noncoincident Drivers in the Journal of the Audio Engineering Society. It is also known as a Butterworth squared filter. A Linkwitz–Riley "L-R" crossover consists of a parallel combination of a low-pass and a high-pass L-R filter. The filters are usually designed by cascading two Butterworth filters, each of which has −3 dB gain at the cut-off frequency. The resulting Linkwitz–Riley filter has −6 dB gain at the cut-off frequency. This means that, upon summing the low-pass and high-pass outputs, the gain at the crossover frequency will be 0 dB, so the crossover behaves like an all-pass filter, having a flat amplitude response with a smoothly changing phase response. This is the biggest advantage of L-R crossovers compared to even-order Butterworth crossovers, whose summed output has a +3 dB peak around the crossover frequency. Since cascading two nth-order Butterworth filters will give a (2n)th-order Linkwitz–Riley filter, theoretically any (2n)th-order Linkwitz–Riley crossover can be designed. However, crossovers of order higher than 4 may have less usability due to their complexity and the increasing size of the peak in group delay around the crossover frequency.
Common types
Second-order Linkwitz–Riley crossover (LR2, LR-2)
Second-order Linkwitz–Riley crossovers (LR2) have a 12 dB/octave (40 dB/decade) slope. They can be realized by cascading two one-pole filters, or using a Sallen Key filter topology with a Q0 value of 0.5. There is a 180° phase difference between the low-pass and high-pass output of the filter, which can be corrected by inverting one signal. In loudspeakers this is usually done by reversing the polarity of one driver if the crossover is passive. For active crossovers inversion is usually done using a
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https://en.wikipedia.org/wiki/Substantia%20innominata
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The substantia innominata also innominate substance, or substantia innominata of Meynert (Latin for unnamed substance) is a series of layers in the human brain consisting partly of gray and partly of white matter, which lies below the anterior part of the thalamus and lentiform nucleus. It is included as part of the anterior perforated substance (as it appears to be perforated by many holes which are actually blood vessels). It is part of the basal forebrain structures and includes the nucleus basalis. A portion of the substantia innominata, below the globus pallidus is considered as part of the extended amygdala.
Layers
It consists of three layers, superior, middle, and inferior.
The superior layer is named the ansa lenticularis, and its fibers, derived from the medullary lamina of the lentiform nucleus, pass medially to end in the thalamus and subthalamic region, while others are said to end in the tegmentum and red nucleus.
The middle layer consists of nerve cells and nerve fibers; fibers enter it from the parietal lobe through the external capsule, while others are said to connect it with the medial longitudinal fasciculus.
The inferior layer forms the main part of the inferior stalk of the thalamus, and connects this body with the temporal lobe and the insula.
Striatopallidal system
In the late 20th century following improved imaging by staining it was reclassified as part of the striatopallidal system, which is made up of the dorsal striatum and dorsal pallidum, and the ventral striatum and ventral pallidum.
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https://en.wikipedia.org/wiki/Spiral%20ganglion
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The spiral (cochlear) ganglion is a group of neuron cell bodies in the modiolus, the conical central axis of the cochlea. These bipolar neurons innervate the hair cells of the organ of Corti. They project their axons to the ventral and dorsal cochlear nuclei as the cochlear nerve, a branch of the vestibulocochlear nerve (CN VIII).
Structure
Neurons whose cell bodies lie in the spiral ganglion are strung along the bony core of the cochlea, and send fibers (axons) into the central nervous system (CNS). These bipolar neurons are the first neurons in the auditory system to fire an action potential, and supply all of the brain's auditory input. Their dendrites make synaptic contact with the base of hair cells, and their axons are bundled together to form the auditory portion of eighth cranial nerve. The number of neurons in the spiral ganglion is estimated to be about 35,000–50,000.
Two apparent subtypes of spiral ganglion cells exist. Type I spiral ganglion cells comprise the vast majority of spiral ganglion cells (90-95% in cats and 88% in humans), and exclusively innervate the inner hair cells. They are myelinated, bipolar neurons. Type II spiral ganglion cells make up the remainder. In contrast to Type I cells, they are unipolar and unmyelinated in most mammals. They innervate the outer hair cells, with each Type II neuron sampling many (15-20) outer hair cells. In addition, outer hair cells form reciprocal synapses onto Type II spiral ganglion cells, suggesting that the Type II cells have both afferent and efferent roles.
Development
The rudiment of the cochlear nerve appears about the end of the third week as a group of ganglion cells closely applied to the cephalic edge of the auditory vesicle. The ganglion gradually splits into two parts, the vestibular ganglion and the spiral ganglion. The axons of neurons in the spiral ganglion travel to the brainstem, forming the cochlear nerve.
Gallery
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https://en.wikipedia.org/wiki/P300-CBP%20coactivator%20family
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The p300-CBP coactivator family in humans is composed of two closely related transcriptional co-activating proteins (or coactivators):
p300 (also called EP300 or E1A binding protein p300)
CBP (also known as CREB-binding protein or CREBBP)
Both p300 and CBP interact with numerous transcription factors and act to increase the expression of their target genes.
Protein structure
p300 and CBP have similar structures. Both contain five protein interaction domains: the nuclear receptor interaction domain (RID), the KIX domain (CREB and MYB interaction domain), the cysteine/histidine regions (TAZ1/CH1 and TAZ2/CH3) and the interferon response binding domain (IBiD). The last four domains, KIX, TAZ1, TAZ2 and IBiD of p300, each bind tightly to
a sequence spanning both transactivation domains 9aaTADs of transcription factor p53.
In addition p300 and CBP each contain a protein or histone acetyltransferase (PAT/HAT) domain and a bromodomain that binds acetylated lysines and a PHD finger motif with unknown function. The conserved domains are connected by long stretches of unstructured linkers.
Regulation of gene expression
p300 and CBP are thought to increase gene expression in three ways:
by relaxing the chromatin structure at the gene promoter through their intrinsic histone acetyltransferase (HAT) activity.
recruiting the basal transcriptional machinery including RNA polymerase II to the promoter.
acting as adaptor molecules.
p300 regulates transcription by directly binding to transcription factors (see external reference for explanatory image). This interaction is managed by one or more of the p300 domains: the nuclear receptor interaction domain (RID), the CREB and MYB interaction domain (KIX), the cysteine/histidine regions (TAZ1/CH1 and TAZ2/CH3) and the interferon response binding domain (IBiD). The last four domains, KIX, TAZ1, TAZ2 and IBiD of p300, each bind tightly to a sequence spanning both transactivation domains 9aaTADs of transcription factor p53.
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https://en.wikipedia.org/wiki/Hyalin
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Hyalin is a protein released from the cortical granules of a fertilized animal egg. The released hyalin modifies the extracellular matrix of the fertilized egg to block other sperm from binding to the egg, and is known as the slow-block to polyspermy. All animals have this slow-block mechanism.
Hyalin is a large, acidic protein which aids in embryonic development. The protein has strong adhesive properties which can help with cell differentiation and as a polyspermy prevention component. It forms the hyaline layer which covers the surface of the egg after insemination.
Structure
Its physical structure has a major and minor component. One is filamentous, having flexible molecules containing a globular domain head at the end. Its conformation is retained mainly by disulfide bonds, as virtually all cysteine amino acids are found in the disulfide form, but also hydrophobic forces and salt linkages stabilize the molecule. The filament length is about 75 nm long, and the head being club-shaped with a diameter of 12 nm. An isoform of the molecule exists, having a longer filament of 125 nm instead. Both forms of these filaments often fold on themselves, making the protein heterogeneous, resulting in poorly resolved stains on a gel. This makes the exact mass uncertain, as the protein is very difficult to purify. Estimates place the mass at about 350 kDa. About 2-3% of its mass is carbohydrates. Aggregates of hyalin also form by associating the heads of the protein, and hyalin remains accociated with a high, molecular weight core protein throughout purification.
Hyalin mRNA is about 12kb in length. It encodes for approximately 25% acidic residues with only 3.5% basic residues. Within its sequence is a region containing tandem repeats of about 84 amino acids. This sequence is highly conserved between species, and is believed to be the adhesive substrate of hyalin. A recombinant part of this sequence was created and its adhesive properties were tested.
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https://en.wikipedia.org/wiki/First%20moment%20of%20area
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The first moment of area is based on the mathematical construct moments in metric spaces. It is a measure of the spatial distribution of a shape in relation to an axis.
The first moment of area of a shape, about a certain axis, equals the sum over all the infinitesimal parts of the shape of the area of that part times its distance from the axis [Σad].
First moment of area is commonly used to determine the centroid of an area.
Definition
Given an area, A, of any shape, and division of that area into n number of very small, elemental areas (dAi). Let xi and yi be the distances (coordinates) to each elemental area measured from a given x-y axis. Now, the first moment of area in the x and y directions are respectively given by:
and
The SI unit for first moment of area is a cubic metre (m3). In the American Engineering and Gravitational systems the unit is a cubic foot (ft3) or more commonly inch3.
The static or statical moment of area, usually denoted by the symbol Q, is a property of a shape that is used to predict its resistance to shear stress. By definition:
where
Qj,x – the first moment of area "j" about the neutral x axis of the entire body (not the neutral axis of the area "j");
dA – an elemental area of area "j";
y – the perpendicular distance to the centroid of element dA from the neutral axis x.
Shear stress in a semi-monocoque structure
The equation for shear flow in a particular web section of the cross-section of a semi-monocoque structure is:
q – the shear flow through a particular web section of the cross-section
Vy – the shear force perpendicular to the neutral axis x through the entire cross-section
Sx – the first moment of area about the neutral axis x for a particular web section of the cross-section
Ix – the second moment of area about the neutral axis x for the entire cross-section
Shear stress may now be calculated using the following equation:
– the shear stress through a particular web section of the cross-section
q – the
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https://en.wikipedia.org/wiki/Pierre%20Fr%C3%A9d%C3%A9ric%20Sarrus
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Pierre Frédéric Sarrus (; 10 March 1798, Saint-Affrique – 20 November 1861) was a French mathematician.
Sarrus was a professor at the University of Strasbourg, France (1826–1856) and a member of the French Academy of Sciences in Paris (1842). He is the author of several treatises, including one on the solution of numeric equations with multiple unknowns (1842); one on multiple integrals and their integrability conditions; and one on the determination of the orbits of the comets. He also discovered a mnemonic rule for solving the determinant of a 3-by-3 matrix, named Sarrus' scheme. Sarrus also demonstrated the fundamental lemma of the calculus of variations.
Sarrus numbers are pseudoprimes to base 2.
Sarrus also developed the Sarrus linkage, the first linkage capable of transforming rotary motion into perfect straight-line motion, and vice versa.
1798 births
1861 deaths
People from Saint-Affrique
19th-century French mathematicians
Linear algebraists
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https://en.wikipedia.org/wiki/Shear%20flow
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In fluid dynamics, shear flow is the flow induced by a force in a fluid. In solid mechanics, shear flow is the shear stress over a distance in a thin-walled structure.
In solid mechanics
For thin-walled profiles, such as that through a beam or semi-monocoque structure, the shear stress distribution through the thickness can be neglected. Furthermore, there is no shear stress in the direction normal to the wall, only parallel. In these instances, it can be useful to express internal shear stress as shear flow, which is found as the shear stress multiplied by the thickness of the section. An equivalent definition for shear flow is the shear force V per unit length of the perimeter around a thin-walled section. Shear flow has the dimensions of force per unit of length. This corresponds to units of newtons per meter in the SI system and pound-force per foot in the US.
Origin
When a transverse force is applied to a beam, the result is variation in bending normal stresses along the length of the beam. This variation causes a horizontal shear stress within the beam that varies with distance from the neutral axis in the beam. The concept of complementary shear then dictates that a shear stress also exists across the cross section of the beam, in the direction of the original transverse force. As described above, in thin-walled structures, the variation along the thickness of the member can be neglected, so the shear stress across the cross section of a beam that is composed of thin-walled elements can be examined as shear flow, or the shear stress multiplied by the thickness of the element.
Applications
The concept of shear flow is particularly useful when analyzing semi-monocoque structures, which can be idealized using the skin-stringer model. In this model, the longitudinal members, or stringers, carry only axial stress, while the skin or web resists the externally applied torsion and shear force. In this case, since the skin is a thin-walled structure, the interna
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https://en.wikipedia.org/wiki/Sink%20%28computing%29
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In computing, a sink, or data sink generally refers to the destination of data flow.
The word sink has multiple uses in computing. In software engineering, an event sink is a class or function that receives events from another object or function, while a sink can also refer to a node of a directed acyclic graph with no additional nodes leading out from it, among other uses.
In software engineering
An event sink is a class or function designed to receive incoming events from another object or function. This is commonly implemented in C++ as callbacks. Other object-oriented languages, such as Java and C#, have built-in support for sinks by allowing events to be fired to delegate functions.
Due to lack of formal definition, a sink is often misconstrued with a gateway, which is a similar construct but the latter is usually either an end-point or allows bi-direction communication between dissimilar systems, as opposed to just an event input point . This is often seen in C++ and hardware-related programming , thus the choice of nomenclature by a developer usually depends on whether the agent acting on a sink is a producer or consumer of the sink content.
In graph theory
In a Directed acyclic graph, a source node is a node (also known as a vertex) with no incoming connections from other nodes, while a sink node is a node without outgoing connections.
Directed acyclic graphs are used in instruction scheduling, neural networks and data compression.
In stream processing
In several computer programs employing streams, such as GStreamer, PulseAudio, or PipeWire, a source is the starting point of a pipeline which produces a stream but does not consume any, while a sink is the end point which accepts a stream without producing any.
An example is an audio pipeline in the PulseAudio sound system. An input device such as a microphone is a type of audio source, while an output device like a speaker is the audio sink.
Other uses
The word sink has been used for both in
|
https://en.wikipedia.org/wiki/Amnesic%20shellfish%20poisoning
|
Amnesic shellfish poisoning (ASP) is an illness caused by consumption of shellfish that contain the marine biotoxin called domoic acid. In mammals, including humans, domoic acid acts as a neurotoxin, causing permanent short-term memory loss, brain damage, and death in severe cases.
This toxin is produced naturally by marine diatoms belonging to the genus Pseudo-nitzschia and the species Nitzschia navis-varingica. When accumulated in high concentrations by shellfish during filter feeding, domoic acid can then be passed on to birds, marine mammals, and humans by consumption of the contaminated shellfish.
Although human illness due to domoic acid has only been associated with shellfish, the toxin can bioaccumulate in many marine organisms that consume phytoplankton, such as anchovies and sardines. Intoxication by domoic acid in nonhuman organisms is frequently referred to as domoic acid poisoning.
Symptoms and treatment
In the brain, domoic acid especially damages the hippocampus and amygdaloid nucleus. It damages the neurons by activating AMPA and kainate receptors, causing an influx of calcium. Although calcium flowing into cells is a normal event, the uncontrolled increase of calcium causes the cell to degenerate.
Gastrointestinal symptoms can appear 24 hours after ingestion of affected molluscs. They may include vomiting, nausea, diarrhea, abdominal cramps, and haemorrhagic gastritis. In more severe cases, neurological symptoms can take several hours or up to 3 days to develop. These include headache, dizziness, disorientation, vision disturbances, loss of short-term memory, motor weakness, seizures, profuse respiratory secretions, hiccups, unstable blood pressure, abnormal heart rhythms, and coma.
People poisoned with very high doses of the toxin or displaying risk factors, such as old age and kidney failure, can die. Death has occurred in four of 107 confirmed cases. In a few cases, permanent sequelae included short-term memory loss and peripheral polyne
|
https://en.wikipedia.org/wiki/Eulerian%20number
|
In combinatorics, the Eulerian number is the number of permutations of the numbers 1 to in which exactly elements are greater than the previous element (permutations with "ascents").
Leonhard Euler investigated them and associated polynomials in his 1755 book Institutiones calculi differentialis.
Other notations for are and .
Definition
The Eulerian polynomials are defined by the exponential generating function
The Eulerian numbers may be defined as the coefficients of the Eulerian polynomials:
An explicit formula for is
Basic properties
For fixed there is a single permutation which has 0 ascents: . Indeed, as for all , . This formally includes the empty collection of numbers, . And so .
For the explicit formula implies , a sequence in that reads .
Fully reversing a permutation with ascents creates another permutation in which there are ascents. Therefore . So there is also a single permutation which has ascents, namely the rising permutation . So also equals .
A lavish upper bound is . Between the bounds just discussed, the value exceeds .
For , the values are formally zero, meaning many sums over can be written with an upper index only up to . It also means that the polynomials are really of degree for .
A tabulation of the numbers in a triangular array is called the Euler triangle or Euler's triangle. It shares some common characteristics with Pascal's triangle. Values of for are:
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| 1 || 57 || 302 || 302 || 57 || 1 || || ||
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! 7
| 1 || 120 || 1191 || 2416 || 1191 || 120 || 1 || ||
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https://en.wikipedia.org/wiki/Constructive%20set%20theory
|
Axiomatic constructive set theory is an approach to mathematical constructivism following the program of axiomatic set theory.
The same first-order language with "" and "" of classical set theory is usually used, so this is not to be confused with a constructive types approach.
On the other hand, some constructive theories are indeed motivated by their interpretability in type theories.
In addition to rejecting the principle of excluded middle (), constructive set theories often require some logical quantifiers in their axioms to be set bounded, motivated by results tied to impredicativity.
Introduction
Constructive outlook
Preliminary on the use of intuitionistic logic
The logic of the set theories discussed here is constructive in that it rejects the principle of excluded middle , i.e. that the disjunction automatically holds for all propositions . As a rule, to prove the excluded middle for a proposition , i.e. to prove the particular disjunction , either or needs to be explicitly proven. When either such proof is established, one says the proposition is decidable, and this then logically implies the disjunction holds. Similarly, a predicate for in a domain is said to be decidable when the more intricate statement is provable. Non-constructive axioms may enable proofs that formally claim decidability of such (and/or ) in the sense that they prove excluded middle for (resp. the statement using the quantifier above) without demonstrating the truth of either side of the disjunction(s). This is often the case in classical logic. In contrast, axiomatic theories deemed constructive tend to not permit many classical proofs of statements involving properties that are provenly computationally undecidable.
The law of noncontradiction is a special case of the propositional form of modus ponens. Using the former with any negated statement , one valid De Morgan's law thus implies already in the more conservative minimal logic. In words, intuitionistic logic st
|
https://en.wikipedia.org/wiki/Absolute%20value%20%28algebra%29
|
In algebra, an absolute value (also called a valuation, magnitude, or norm, although "norm" usually refers to a specific kind of absolute value on a field) is a function which measures the "size" of elements in a field or integral domain. More precisely, if D is an integral domain, then an absolute value is any mapping |x| from D to the real numbers R satisfying:
It follows from these axioms that |1| = 1 and |-1| = 1. Furthermore, for every positive integer n,
|n| = |1 + 1 + ... + 1 (n times)| = |−1 − 1 − ... − 1 (n times)| ≤ n.
The classical "absolute value" is one in which, for example, |2|=2, but many other functions fulfill the requirements stated above, for instance the square root of the classical absolute value (but not the square thereof).
An absolute value induces a metric (and thus a topology) by
Examples
The standard absolute value on the integers.
The standard absolute value on the complex numbers.
The p-adic absolute value on the rational numbers.
If R is the field of rational functions over a field F and is a fixed irreducible element of R, then the following defines an absolute value on R: for in R define to be , where and
Types of absolute value
The trivial absolute value is the absolute value with |x|=0 when x=0 and |x|=1 otherwise. Every integral domain can carry at least the trivial absolute value. The trivial value is the only possible absolute value on a finite field because any non-zero element can be raised to some power to yield 1.
If an absolute value satisfies the stronger property |x + y| ≤ max(|x|, |y|) for all x and y, then |x| is called an ultrametric or non-Archimedean absolute value, and otherwise an Archimedean absolute value.
Places
If |x|1 and |x|2 are two absolute values on the same integral domain D, then the two absolute values are equivalent if |x|1 < 1 if and only if |x|2 < 1 for all x. If two nontrivial absolute values are equivalent, then for some exponent e we have |x|1e = |x|2 for all x. Raising an absolute
|
https://en.wikipedia.org/wiki/NLTSS
|
The Network Livermore Timesharing System (NLTSS, also sometimes the New Livermore Time Sharing System) is an operating system that was actively developed at Lawrence Livermore Laboratory (now Lawrence Livermore National Laboratory) from 1979 until about 1988, though it continued to run production applications until 1995. An earlier system, the Livermore Time Sharing System had been developed over a decade earlier.
NLTSS ran initially on a CDC 7600 computer, but only ran production from about 1985 until 1994 on Cray computers including the Cray-1, Cray X-MP, and Cray Y-MP models.
Characteristics
The NLTSS operating system was unusual in many respects and unique in some.
Low-level architecture
NLTSS was a microkernel message passing system. It was unique in that only one system call was supported by the kernel of the system. That system call, which might be called "communicate" (it didn't have a name because it didn't need to be distinguished from other system calls) accepted a list of "buffer tables" (e.g., see The NLTSS Message System Interface) that contained control information for message communication – either sends or receives. Such communication, both locally within the system and across a network was all the kernel of the system supported directly for user processes. The "message system" (supporting the one call and the network protocols) and drivers for the disks and processor composed the entire kernel of the system.
Mid-level architecture
NLTSS is a capability-based security client–server system. The two primary servers are the file server and the process server. The file server was a process privileged to be trusted by the drivers for local storage (disk storage,) and the process server was a process privileged to be trusted by the processor driver (software that switched time sharing control between processes in the "alternator", handled interrupts for processes besides the "communicate" call, provided access to memory and process state for the proce
|
https://en.wikipedia.org/wiki/Calcium%20lactate%20gluconate
|
Calcium lactate gluconate, also known as GLOCAL, is a soluble salt of calcium, lactic acid and gluconic acid used in effervescent calcium tablets. Its chemical formula is Ca5(C3H5O3)6·(C6H11O7)4·2H2O. It was first developed by Sandoz, Switzerland. Calcium lactate gluconate is used in the functional and fortified food industry due to its good solubility and neutral taste. In addition, it is used in various spherification techniques in molecular gastronomy. It can also be used to help neutralize HF (hydrofluoric acid) poisoning.
|
https://en.wikipedia.org/wiki/Wikipedia
|
Wikipedia is a free-content online encyclopedia written and maintained by a community of volunteers, collectively known as Wikipedians, through open collaboration and using a wiki-based editing system called MediaWiki. Wikipedia is the largest and most-read reference work in history, and has consistently been one of the 10 most popular websites. Founded by Jimmy Wales and Larry Sanger on January 15, 2001, it is hosted by the Wikimedia Foundation, an American nonprofit organization.
Initially only available in English, editions in other languages were quickly developed. Wikipedia's editions when combined, comprise more than articles, attracting around 2billion unique device visits per month and more than 15 million edits per month (about 5.8edits per second on average) .
Wikipedia has been praised for its enablement of the democratization of knowledge, extent of coverage, unique structure, and culture. It has been criticized for exhibiting systemic bias, particularly gender bias against women and geographical bias against the Global South. While the reliability of Wikipedia was frequently criticized in the 2000s, it has improved over time, receiving greater praise in the late 2010s and early 2020s, having become an important fact-checking site. It has been censored by some national governments, ranging from specific pages to the entire site. Articles on breaking news are often accessed as sources of frequently updated information about those events.
History
Nupedia
Various collaborative online encyclopedias were attempted before the start of Wikipedia, but with limited success. Wikipedia began as a complementary project for Nupedia, a free online English-language encyclopedia project whose articles were written by experts and reviewed under a formal process. It was founded on March 9, 2000, under the ownership of Bomis, a web portal company. Its main figures were Bomis CEO Jimmy Wales and Larry Sanger, editor-in-chief for Nupedia and later Wikipedia. Nupedia
|
https://en.wikipedia.org/wiki/Chain%20of%20trust
|
In computer security, a chain of trust is established by validating each component of hardware and software from the end entity up to the root certificate. It is intended to ensure that only trusted software and hardware can be used while still retaining flexibility.
Introduction
A chain of trust is designed to allow multiple users to create and use the software on the system, which would be more difficult if all the keys were stored directly in hardware. It starts with hardware that will only boot from software that is digitally signed. The signing authority will only sign boot programs that enforce security, such as only running programs that are themselves signed, or only allowing signed code to have access to certain features of the machine. This process may continue for several layers.
This process results in a chain of trust. The final software can be trusted to have certain properties because if it had been illegally modified its signature would be invalid, and the previous software would not have executed it. The previous software can be trusted, because it, in turn, would not have been loaded if its signature had been invalid. The trustworthiness of each layer is guaranteed by the one before, back to the trust anchor.
It would be possible to have the hardware check the suitability (signature) for every single piece of software. However, this would not produce the flexibility that a "chain" provides. In a chain, any given link can be replaced with a different version to provide different properties, without having to go all the way back to the trust anchor. This use of multiple layers is an application of a general technique to improve scalability and is analogous to the use of multiple certificates in a certificate chain.
Computer security
In computer security, digital certificates are verified using a chain of trust. The trust anchor for the digital certificate is the root certificate authority (CA).
The certificate hierarchy is a structure of certi
|
https://en.wikipedia.org/wiki/Belt%20transect
|
Belt transects are used in biology, more specifically in biostatistics, to estimate the distribution of organisms in relation to a certain area, such as the seashore or a meadow.
The belt transect method is similar to the line transect method but gives information on abundance as well as presence, or absence of species.
Method
The method involves laying out a transect line and then placing quadrats over the line, starting the quadrat at the first marked point of the line. Any consistent measurement size for the quadrat and length of the line can be chosen, depending on the species. With the quadrats applied, all the individuals of a species can be counted, and the species abundance can be estimated. The method is also suitable for long-term observations with a permanent installation.
|
https://en.wikipedia.org/wiki/Pauli%20group
|
In physics and mathematics, the Pauli group on 1 qubit is the 16-element matrix group consisting of the 2 × 2 identity matrix and all of the Pauli matrices
,
together with the products of these matrices with the factors and :
.
The Pauli group is generated by the Pauli matrices, and like them it is named after Wolfgang Pauli.
The Pauli group on qubits, , is the group generated by the operators described above applied to each of qubits in the tensor product Hilbert space .
As an abstract group, is the central product of a cyclic group of order 4 and the dihedral group of order 8.
The Pauli group is a representation of the gamma group in three-dimensional Euclidean space. It is not isomorphic to the gamma group; it is less free, in that its chiral element is whereas there is no such relationship for the gamma group.
|
https://en.wikipedia.org/wiki/Stabilizer%20code
|
The theory of quantum error correction plays a prominent role in the practical realization and engineering of
quantum computing and quantum communication devices. The first quantum
error-correcting codes are strikingly similar to classical block codes in their
operation and performance. Quantum error-correcting codes restore a noisy,
decohered quantum state to a pure quantum state. A
stabilizer quantum error-correcting code appends ancilla qubits
to qubits that we want to protect. A unitary encoding circuit rotates the
global state into a subspace of a larger Hilbert space. This highly entangled,
encoded state corrects for local noisy errors. A quantum error-correcting code makes quantum computation
and quantum communication practical by providing a way for a sender and
receiver to simulate a noiseless qubit channel given a noisy qubit channel
whose noise conforms to a particular error model.
The stabilizer theory of quantum error correction allows one to import some
classical binary or quaternary codes for use as a quantum code. However, when importing the
classical code, it must satisfy the dual-containing (or self-orthogonality)
constraint. Researchers have found many examples of classical codes satisfying
this constraint, but most classical codes do not. Nevertheless, it is still useful to import classical codes in this way (though, see how the entanglement-assisted stabilizer formalism overcomes this difficulty).
Mathematical background
The stabilizer formalism exploits elements of
the Pauli group in formulating quantum error-correcting codes. The set
consists of the Pauli operators:
The above operators act on a single qubit – a state represented by a vector in a two-dimensional
Hilbert space. Operators in have eigenvalues and either commute
or anti-commute. The set consists of -fold tensor products of
Pauli operators:
Elements of act on a quantum register of qubits. We
occasionally omit tensor product symbols in what follows so that
The -fold P
|
https://en.wikipedia.org/wiki/Basal%20plate%20%28placenta%29
|
During pregnancy changes in the placenta involve the disappearance of the greater portion of the stratum compactum, but the deeper part of this layer persists and is condensed to form what is known as the basal plate. Between this plate and the uterine muscular fibres are the stratum spongiosum and the boundary layer; through these and the basal plate the uterine arteries and veins pass to and from the intervillous space. Decidual septum is one of the structures derived from basal plate.
|
https://en.wikipedia.org/wiki/Stomatognathic%20system
|
The stomatognathic system is an anatomical system comprising the teeth, jaws, and associated soft tissues. It was formerly called the stomognathic system.
Stomatognathic diseases are treated by dentists, maxillofacial surgeons, ear, nose, and throat specialists, speech therapists, occupational therapists, myofunctional therapists, and physical therapists.
|
https://en.wikipedia.org/wiki/Lightweight%20software%20test%20automation
|
Lightweight software test automation is the process of creating and using relatively short and simple computer programs, called lightweight test harnesses, designed to test a software system. Lightweight test automation harnesses are not tied to a particular programming language but are most often implemented with the Java, Perl, Visual Basic .NET, and C# programming languages. Lightweight test automation harnesses are generally four pages of source code or less, and are generally written in four hours or less. Lightweight test automation is often associated with Agile software development methodology.
The three major alternatives to the use of lightweight software test automation are commercial test automation frameworks, Open Source test automation frameworks, and heavyweight test automation. The primary disadvantage of lightweight test automation is manageability. Because lightweight automation is relatively quick and easy to implement, a test effort can be overwhelmed with harness programs, test case data files, test result files, and so on. However, lightweight test automation has significant advantages. Compared with commercial frameworks, lightweight automation is less expensive in initial cost and is more flexible. Compared with Open Source frameworks, lightweight automation is more stable because there are fewer updates and external dependencies. Compared with heavyweight test automation, lightweight automation is quicker to implement and modify. Lightweight test automation is generally used to complement, not replace these alternative approaches.
Lightweight test automation is most useful for regression testing, where the intention is to verify that new source code added to the system under test has not created any new software failures. Lightweight test automation may be used for other areas of software testing such as performance testing, stress testing, load testing, security testing, code coverage analysis, mutation testing, and so on. The most widel
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