source
stringlengths 31
227
| text
stringlengths 9
2k
|
|---|---|
https://en.wikipedia.org/wiki/Polycide
|
Polycide is a silicide formed over polysilicon. Widely used in DRAMs. In a polycide MOSFET transistor process, the silicide is formed only over the polysilicon film as formation occurs prior to any polysilicon etch. Polycide processes contrast with salicide processes in which silicide is formed after the polysilicon etch. Thus, with a salicide process, silicide is formed over both the polysilicon gate and the exposed monocrystalline terminal regions of the transistor in a self-aligned fashion.
Semiconductor device fabrication
Silicon
|
https://en.wikipedia.org/wiki/Guido%20Stampacchia
|
Guido Stampacchia (26 March 1922 – 27 April 1978) was an Italian mathematician, known for his work on the theory of variational inequalities, the calculus of variation and the theory of elliptic partial differential equations.
Life and academic career
Stampacchia was born in Naples, Italy, to Emanuele Stampacchia and Giulia Campagnano. He obtained his high school certification from the Liceo-Ginnasio Giambattista Vico in Naples in classical subjects, although he showed a stronger aptitude for mathematics and physics.
In 1940 he was admitted to the Scuola Normale Superiore di Pisa for undergraduate studies in pure mathematics. He was drafted in March 1943 but nevertheless managed to take examinations during the summer before joining the resistance movement against the Germans in the defence of Rome in September. He was discharged in June 1945.
In 1944 he won a scholarship to the University of Naples which allowed him to continue his studies. In the 1945–1946 academic year he declined a specialization at the Scuola Normale in the Faculty of Sciences in favour of an assistant position at the Istituto Universitario Navale. In 1949 he was appointed as assistant with tenure to the chair of mathematical analysis, and in 1951 he obtained his "Libera docenza".
In 1952 won a national competition for the chair at the University of Palermo. He was nominated Professor on Probation at the University of Genoa later the same year and was promoted to full Professor in 1955.
He married fellow student Sara Naldini in October 1948. Children Mauro, Renata, Giulia, and Franca were born in 1949, 1951, 1955 and 1956 respectively.
Stampacchia was active in research and teaching throughout his career. He made key contributions to a number of fields, including calculus of variation, variational inequalities and differential equations. In 1967 Stampacchia was elected President of the Unione Matematica Italiana. It was about this time that his research efforts shifted toward the emerging f
|
https://en.wikipedia.org/wiki/Dissociative%20recombination
|
Dissociative recombination is a chemical process in which a positive polyatomic ion recombines with an electron, and as a result, the neutral molecule dissociates. This reaction is important for interstellar and atmospheric chemistry. On Earth, dissociative recombination rarely occurs naturally, as free electrons react with any molecule (even neutral molecules) they encounter. Even in the best laboratory conditions, dissociative recombination is hard to observe, but it is an important reaction in systems which have large populations of ionized molecules such as atmospheric-pressure plasmas.
In astrophysics, dissociative recombination is one of the main mechanisms by which molecules are broken down, and other molecules are formed. The existence of dissociative recombination is possible due to the vacuum of the interstellar medium. A typical example of dissociative recombination in astrophysics is:
CH3+ + e- -> CH2 + H
See also
Astrochemistry
Ionization
|
https://en.wikipedia.org/wiki/Sunward%20Aerospace%20Group
|
Sunward Aerospace is the short name of an incorporated company started in early 2000 producing a line of model rockets. Originally called Sunward Model Aerospace, the name is now Sunward Aerospace Group Limited. The company is located in Toronto, Ontario, Canada.
The company switched owners in October 2004 and since expanded the line of model rockets including general rockets, payload, and pyramid rockets. Sunward Aerospace also produces a line of wood kits which include a trebuchet, a catapult, a ballista and an elastic powered racer.
The company introduced additions to the line of model rockets in April 2007 and also added a paper telescope kit for the school market.
In July 2013, the company expanded Canadian operations by opening a retail hobby store in Toronto serving the Canadian market.
|
https://en.wikipedia.org/wiki/Acid%20phosphatase
|
Acid phosphatase (EC 3.1.3.2, systematic name phosphate-monoester phosphohydrolase (acid optimum)) is an enzyme that frees attached phosphoryl groups from other molecules during digestion. It can be further classified as a phosphomonoesterase. It is stored in lysosomes and functions when these fuse with endosomes, which are acidified while they function; therefore, it has an acid pH optimum. This enzyme is present in many animal and plant species.
Different forms of acid phosphatase are found in different organs, and their serum levels are used to evaluate the success of the surgical treatment of prostate cancer. In the past, they were also used to diagnose this type of cancer.
It's also used as a cytogenetic marker to distinguish the two different lineages of acute lymphoblastic leukemia (ALL) : B-ALL (a leukemia of B lymphocytes) is acid-phosphatase negative , T-ALL (originating instead from T Lymphocytes) is acid-phosphatase positive .
Acid phosphatase catalyzes the following reaction at an optimal acidic pH (below 7):
a phosphate monoester + H2O = an alcohol + phosphate
Phosphatase enzymes are also used by soil microorganisms to access organically bound phosphate nutrients. An assay on the rates of activity of these enzymes may be used to ascertain biological demand for phosphates in the soil.
Some plant roots, especially cluster roots, exude carboxylates that perform acid phosphatase activity, helping to mobilise phosphorus in nutrient-deficient soils.
Certain bacteria, such as Nocardia, can degrade this enzyme and utilize it as a carbon source.
Bone acid phosphatase
Tartrate-resistant acid phosphatase may be used as a biochemical marker of osteoclast function during the process of bone resorption.
Genes
The following genes encode the polypeptide components for various acid phosphatase isoenzymes:
ACP1
ACP2
ACPP (ACP3), prostatic acid phosphatase
ACP5, tartrate-resistant acid phosphatase
ACP6
ACPT, testicular acid phosphatase
Tissue acid phosphatase,
|
https://en.wikipedia.org/wiki/UniVBE
|
UniVBE (short for Universal VESA BIOS Extensions) is a software driver that allows DOS applications written to the VESA BIOS standard to run on almost any display device made in the last 15 years or so.
The UniVBE driver was written by SciTech Software and is also available in their product called SciTech Display Doctor.
The primary benefit is increased compatibility and performance with DOS games. Many video cards have sub-par implementations of the VESA standards, or no support at all. UNIVBE replaces the card's built-in support. Many DOS games include a version of UNIVBE because VESA issues were so widespread.
According to SciTech Software Inc, SciTech Display Doctor is licensed by IBM as the native graphics driver solution for OS/2.
History
The software started out as The Universal VESA TSR (UNIVESA), written by Kendall Bennett. It was renamed to Universal VESA BIOS Extensions (UniVBE) in version 4.2 at the request of VESA organisation, and is no longer freeware.
In version 5.1, VBE/Core 2.0 support was added.
In version 5.2, it was renamed to Scitech Display Doctor. However, UniVBE continued to be the name used for the actual driver.
Version 6 included support of VBE/Core 3.0, VBE/SCI.
Version 6.5 introduced the ability to use Scitech Display Doctor as wrapper video driver.
Version 7 supports VESA/MCCS and included Scitech GLDirect, an OpenGL emulator. This version was also ported to OS/2 and Linux (as version 1.0). However, the proposed product was never widely available. Only pre-releases were available to the public. In the Windows SDD prerelease, it included DOS UniVBE driver 7.20 beta, the Scitech Nucleus Graphics driver, GLDirect 2.0 and 3.0 beta. SDD 7 was first released on OS/2 on February 28, 2002, followed by a Windows beta on March 1, 2002.
SciTech Display Doctor 7.1 marked the final release of SDD, which was available on OS/2, among other operating systems. However, the Scitech Nucleus Graphics engine lived on as SciTech SNAP (System Neu
|
https://en.wikipedia.org/wiki/Algorithmic%20art
|
Algorithmic art or algorithm art is art, mostly visual art, in which the design is generated by an algorithm. Algorithmic artists are sometimes called algorists.
Overview
Algorithmic art, also known as computer-generated art, is a subset of generative art (generated by an autonomous system) and is related to systems art (influenced by systems theory). Fractal art is an example of algorithmic art.
For an image of reasonable size, even the simplest algorithms require too much calculation for manual execution to be practical, and they are thus executed on either a single computer or on a cluster of computers. The final output is typically displayed on a computer monitor, printed with a raster-type printer, or drawn using a plotter. Variability can be introduced by using pseudo-random numbers. There is no consensus as to whether the product of an algorithm that operates on an existing image (or on any input other than pseudo-random numbers) can still be considered computer-generated art, as opposed to computer-assisted art.
History
Roman Verostko argues that Islamic geometric patterns are constructed using algorithms, as are Italian Renaissance paintings which make use of mathematical techniques, in particular linear perspective and proportion.
Some of the earliest known examples of computer-generated algorithmic art were created by Georg Nees, Frieder Nake, A. Michael Noll, Manfred Mohr and Vera Molnár in the early 1960s. These artworks were executed by a plotter controlled by a computer, and were therefore computer-generated art but not digital art. The act of creation lay in writing the program, which specified the sequence of actions to be performed by the plotter. Sonia Landy Sheridan established Generative Systems as a program at the School of the Art Institute of Chicago in 1970 in response to social change brought about in part by the computer-robot communications revolution. Her early work with copier and telematic art focused on the differences betwee
|
https://en.wikipedia.org/wiki/Dacryon
|
The point of junction of the maxillary bone, lacrimal bone, and frontal bone is named the dacryon.
|
https://en.wikipedia.org/wiki/Frontal%20eminence
|
A frontal eminence (or tuber frontale) is either of two rounded elevations on the frontal bone of the skull. They lie about 3 cm above the supraorbital margin on each side of the frontal suture. They are the site of ossification of the frontal bone during embryological development, although may not be the first site.
The frontal eminences vary in size in different individuals, are occasionally asymmetrical, and are especially prominent in young skulls. The surface of the bone above them is smooth, and covered by the epicranial aponeurosis.
See also
Squamous part of the frontal bone
|
https://en.wikipedia.org/wiki/Sergeant%20Stubby
|
Sergeant Stubby (1916 – March 16, 1926) was a dog and the unofficial mascot of the 102nd Infantry Regiment and was assigned to the 26th (Yankee) Division in World War I. He served for 18 months and participated in 17 battles and four offensives on the Western Front. He saved his regiment from surprise mustard gas attacks, found and comforted the wounded, and allegedly once caught a German soldier by the seat of his pants, holding him there until American soldiers found him. His actions were well-documented in contemporary American newspapers.
Stubby has been called the most decorated war dog of the Great War and the only dog to be nominated and promoted to sergeant through combat. Stubby's remains are in the Smithsonian Institution.
Stubby is the subject of the 2018 animated film Sgt. Stubby: An American Hero.
Early life
Stubby was described in contemporaneous news items as a Boston Terrier or "American bull terrier" mutt. Describing him as a dog of "uncertain breed," Ann Bausum wrote that: "The brindle-patterned pup probably owed at least some of his parentage to the evolving family of Boston Terriers, a breed so new that even its name was in flux: Boston Round Heads, American... and Boston Bull Terriers." Stubby was found wandering the grounds of the Yale University campus in New Haven, Connecticut, in July 1917, while members of the 102nd Infantry were training. He hung around as the men drilled and one soldier in particular, Corporal James Robert Conroy (1892–1987), developed a fondness for him. When it came time for the outfit to ship out, Conroy hid Stubby on board the troop ship. As they were getting off the ship in France, he hid Stubby under his overcoat without detection. Upon discovery by Conroy's commanding officer, Stubby saluted him as he had been trained to in camp, and the commanding officer allowed the dog to stay on board.
Military service
Stubby served with the 102nd Infantry Regiment in the trenches in France for 18 months and participated
|
https://en.wikipedia.org/wiki/DISCUS
|
DISCUS, or distributed source coding using syndromes, is a method for distributed source coding. It is a compression algorithm used to compress correlated data sources. The method is designed to achieve the Slepian–Wolf bound by using channel codes.
History
DISCUS was invented by researchers S. S. Pradhan and K. Ramachandran, and first published in their
paper "Distributed source coding using syndromes (DISCUS): design and construction",
published in the IEEE Transactions on Information Theory in 2003.
Variations
Many variations of DISCUS are presented in related literature. One such popular scheme is the Channel Code Partitioning scheme, which is an a-priori scheme, to reach the Slepian–Wolf bound. Many papers illustrate simulations and experiments on channel code partitioning using the turbo codes, Hamming codes and irregular repeat-accumulate codes.
See also
Modulo-N code is a simpler technique for compressing correlated data sources.
Distributed source coding
External links
"Distributed source coding using syndromes (DISCUS): design and construction" by Pradhan, S.S. and Ramchandran, K.
"DISCUS: Distributed Compression for Sensor Networks"
Distributed Source Coding can also be implemented using Convolutional Codes or using Turbo Codes
Information theory
Wireless sensor network
|
https://en.wikipedia.org/wiki/Asymmetric%20induction
|
Asymmetric induction (also enantioinduction) describes the preferential formation in a chemical reaction of one enantiomer or diastereoisomer over the other as a result of the influence of a chiral feature present in the substrate, reagent, catalyst or environment. Asymmetric induction is a key element in asymmetric synthesis.
Asymmetric induction was introduced by Hermann Emil Fischer based on his work on carbohydrates. Several types of induction exist.
Internal asymmetric induction makes use of a chiral center bound to the reactive center through a covalent bond and remains so during the reaction. The starting material is often derived from chiral pool synthesis. In relayed asymmetric induction the chiral information is introduced in a separate step and removed again in a separate chemical reaction. Special synthons are called chiral auxiliaries. In external asymmetric induction chiral information is introduced in the transition state through a catalyst of chiral ligand. This method of asymmetric synthesis is economically most desirable.
Carbonyl 1,2 asymmetric induction
Several models exist to describe chiral induction at carbonyl carbons during nucleophilic additions. These models are based on a combination of steric and electronic considerations and are often in conflict with each other. Models have been devised by Cram (1952), Cornforth (1959), Felkin (1969) and others.
Cram's rule
The Cram's rule of asymmetric induction developed by Donald J. Cram in 1952 is an early concept relating to the prediction of stereochemistry in certain acyclic systems. In full the rule is:
In certain non-catalytic reactions that diastereomer will predominate, which could be formed by the approach of the entering group from the least hindered side when the rotational conformation of the C-C bond is such that the double bond is flanked by the two least bulky groups attached to the adjacent asymmetric center.
The rule indicates that the presence of an asymmetric center in a
|
https://en.wikipedia.org/wiki/Throw%20%28projector%29
|
In video projection terminology, throw is the distance between a video projector lens and the screen on which it shines. It is given as a ratio (called throw ratio), which describes the relationship between the distance to the screen and the width of the screen (assuming the image is to fill the screen fully). Throw ratio is a characteristic of the lens of the projector (although "projector throw" and "lens throw" are often used synonymously). Some projectors (typically larger, more expensive ones) are able to accept a variety of lenses, while lower cost projectors tend to have a permanent lens that is not designed to be changed. Some lenses are fixed at a specific throw ratio, while most are adjustable (zoomable) to a range of throw ratios. Distance to the screen is measured from the front of the lens.
Formula
Distance (D), Width (W), Throw Ratio (R)
If the distance and width are known, calculate the throw ratio using the formula: R = D / W
If the screen width and throw ratio are known, calculate the distance using the equivalent formula: D = W x R
Although it is often stated as a single value (or range of values), throw ratio is a comparison of D : W. To reduce this to a single number (as is typically seen in projector/lens specifications), start by dividing both sides by W, leaving us with D / W : 1. The 1 on the right means "for each one unit of width of the screen, how many units away should the projector be?" In practice the 1 is often assumed (omitted) when listing this specification.
Examples (fixed lenses)
A video projector (lens) with a throw ratio of 2.0 (or "2.0 : 1") would need to be positioned at a distance that is twice the width of the screen. So if the screen is 60" wide, the projector needs to be 120" from the screen.
A video projector (lens) with a throw ratio of 0.4 or less would be positioned relatively close to the screen, and would be considered a "short throw projector".
A video projector that must be positioned very far from the sc
|
https://en.wikipedia.org/wiki/Kaoani
|
Kaoani comes from the Japanese and . Kaoanis are small animated smilies that usually bounce up and down to look like they are floating. Kaoani originate in Japan and are also known as puffs, anime blobs, anikaos or anime emoticons.
Kaoani can take the form of animals, foodstuffs such as rice balls, colorful blobs, cartoon characters, etc. Many are animated to be performing a certain task, such as dancing, laughing, or cheering.
The file format for kaoanis is usually GIF, since it supports animations. However, it is also possible to make them in the APNG format, which is an animated PNG image. Kaoanis are mostly used on internet forums, MySpace profiles, blogs and instant messaging software to show moods or as avatars.
See also
Kaomoji
Emoticon
Smiley
Anime and manga terminology
Internet culture
|
https://en.wikipedia.org/wiki/Nullcline
|
In mathematical analysis, nullclines, sometimes called zero-growth isoclines, are encountered in a system of ordinary differential equations
where here represents a derivative of with respect to another parameter, such as time . The 'th nullcline is the geometric shape for which . The equilibrium points of the system are located where all of the nullclines intersect.
In a two-dimensional linear system, the nullclines can be represented by two lines on a two-dimensional plot; in a general two-dimensional system they are arbitrary curves.
History
The definition, though with the name ’directivity curve’, was used in a 1967 article by Endre Simonyi. This article also defined 'directivity vector' as
,
where P and Q are the dx/dt and dy/dt differential equations, and i and j are the x and y direction unit vectors.
Simonyi developed a new stability test method from these new definitions, and with it he studied differential equations. This method, beyond the usual stability examinations, provided semi-quantitative results.
|
https://en.wikipedia.org/wiki/Fucoidan
|
Fucoidan is a long chain sulfated polysaccharide found in various species of brown algae. Commercially available fucoidan is commonly extracted from the seaweed species Fucus vesiculosus, Cladosiphon okamuranus, Laminaria japonica and Undaria pinnatifida. Variant forms of fucoidan have also been found in animal species, including the sea cucumber.
Fucoidan occurs in the cell walls of the seaweed plant and serves to protect it from external stresses. The same protective benefits that are of value to the seaweed plant have also found to be of potential benefit for both human and animal health. Fucoidan extracts are utilised in a range of therapeutic health care preparations, being incorporated as high value ingredients in nutritional, medical device, skincare and dermatological products.
The bioactivity of fucoidan extracts is largely determined by the fucoidan extraction method and the seaweed species from which it is extracted. Fucoidan extraction methods, purity, bioactivity, global regulatory approvals and source seaweed species vary between fucoidan producers.
History
Fucoidan-containing seaweeds have a rich history of medicinal and therapeutic use. The earliest records have been unearthed at Monte Verde in Chile, where archaeological digs have uncovered evidence of their use dating to circa 12000 BC. Early therapeutic use was also evident in ancient Greek and Roman civilizations. In the 17th century, the English botanist John Gerard noted the use of seaweed to treat a wide variety of ailments.
Fucoidan itself was not isolated and described until the early 1900s. In 1913, Swedish Professor Harald Kylin became the first to describe the slimy film found on many seaweeds as ‘fucoidin’ or ‘fucoijin’. The substance subsequently became known as ‘fucoidan’ based on the international naming convention on sugars.
Research in the early 20th century focused on extracting crude extracts and reconciling some of the conflicting views on fucoidan. Methods of extracts and
|
https://en.wikipedia.org/wiki/SQL%20Server%20Notification%20Services
|
SQL Server Notification Services is a platform developed by Microsoft for the development and deployment of notification applications based on SQL Server technology and the Microsoft .NET Framework. Notification Services offers a scalable server engine on which to run notification applications, with multi-server capability-providing flexibility and scalability for deploying applications.
Notification Services was designed to ease the pain of developing and deploying notification applications that generate personalized, timely information to subscribers.
To design, code and test all of the components that make up a robust Notification Services Application-such as notification scheduling, failure detection, retry logic, time zone management, notification grouping, and queue management, adding Notification Services to software applications can be a daunting task.
Background
Over the years the term Notification applications has been superseded with the term Complex Event Processing (CEP). The idea is that the user defines a set of Rules (or Queries) in advance, and then push data through those rules. Should the data fit any of the criteria of the Rules then some action is fired. For example: A rule may state "If car speed through sensor is above 100 km/h, take photo and record" otherwise all other data is discarded.
This approach is much faster than the traditional OLTP design of; Insert the row(s) into the database while constantly polling the data to see if something relevant has happened. It is especially suited to situations where you have high speed inputs, a fixed set of fairly simple queries and may not need to keep all the data. e.g.: Some industries measure the voltage, current and other attributes of hundreds of electric motors in their conveyor belts, 100 times each second. Then compare each measurement to its average, plant operators are alerted should a sudden change occur.
Release history
SQL Server Notification Services was one of the many component
|
https://en.wikipedia.org/wiki/Parks%E2%80%93McClellan%20filter%20design%20algorithm
|
The Parks–McClellan algorithm, published by James McClellan and Thomas Parks in 1972, is an iterative algorithm for finding the optimal Chebyshev finite impulse response (FIR) filter. The Parks–McClellan algorithm is utilized to design and implement efficient and optimal FIR filters. It uses an indirect method for finding the optimal filter coefficients.
The goal of the algorithm is to minimize the error in the pass and stop bands by utilizing the Chebyshev approximation. The Parks–McClellan algorithm is a variation of the Remez exchange algorithm, with the change that it is specifically designed for FIR filters. It has become a standard method for FIR filter design.
History of optimal FIR filter design
In the 1960s, researchers within the field of analog filter design were using the Chebyshev approximation for filter design. During this time, it was well known that the best filters contain an equiripple characteristic in their frequency response magnitude and the elliptic filter (or Cauer filter) was optimal with regards to the Chebyshev approximation. When the digital filter revolution began in the 1960s, researchers used a bilinear transform to produce infinite impulse response (IIR) digital elliptic filters. They also recognized the potential for designing FIR filters to accomplish the same filtering task and soon the search was on for the optimal FIR filter using the Chebyshev approximation.
It was well known in both mathematics and engineering that the optimal response would exhibit an equiripple behavior and that the number of ripples could be counted using the Chebyshev approximation. Several attempts to produce a design program for the optimal Chebyshev FIR filter were undertaken in the period between 1962 and 1971. Despite the numerous attempts, most did not succeed, usually due to problems in the algorithmic implementation or problem formulation. Otto Herrmann, for example, proposed a method for designing equiripple filters with restricted band edges.
|
https://en.wikipedia.org/wiki/Remez%20algorithm
|
The Remez algorithm or Remez exchange algorithm, published by Evgeny Yakovlevich Remez in 1934, is an iterative algorithm used to find simple approximations to functions, specifically, approximations by functions in a Chebyshev space that are the best in the uniform norm L∞ sense. It is sometimes referred to as Remes algorithm or Reme algorithm.
A typical example of a Chebyshev space is the subspace of Chebyshev polynomials of order n in the space of real continuous functions on an interval, C[a, b]. The polynomial of best approximation within a given subspace is defined to be the one that minimizes the maximum absolute difference between the polynomial and the function. In this case, the form of the solution is precised by the equioscillation theorem.
Procedure
The Remez algorithm starts with the function to be approximated and a set of sample points in the approximation interval, usually the extrema of Chebyshev polynomial linearly mapped to the interval. The steps are:
Solve the linear system of equations
(where ),
for the unknowns and E.
Use the as coefficients to form a polynomial .
Find the set of points of local maximum error .
If the errors at every are of equal magnitude and alternate in sign, then is the minimax approximation polynomial. If not, replace with and repeat the steps above.
The result is called the polynomial of best approximation or the minimax approximation algorithm.
A review of technicalities in implementing the Remez algorithm is given by W. Fraser.
Choice of initialization
The Chebyshev nodes are a common choice for the initial approximation because of their role in the theory of polynomial interpolation. For the initialization of the optimization problem for function f by the Lagrange interpolant Ln(f), it can be shown that this initial approximation is bounded by
with the norm or Lebesgue constant of the Lagrange interpolation operator Ln of the nodes (t1, ..., tn + 1) being
T being the zeros of the Chebyshev p
|
https://en.wikipedia.org/wiki/Minimax%20approximation%20algorithm
|
A minimax approximation algorithm (or L∞ approximation or uniform approximation) is a method to find an approximation of a mathematical function that minimizes maximum error.
For example, given a function defined on the interval and a degree bound , a minimax polynomial approximation algorithm will find a polynomial of degree at most to minimize
Polynomial approximations
The Weierstrass approximation theorem states that every continuous function defined on a closed interval [a,b] can be uniformly approximated as closely as desired by a polynomial function.
For practical work it is often desirable to minimize the maximum absolute or relative error of a polynomial fit for any given number of terms in an effort to reduce computational expense of repeated evaluation.
Polynomial expansions such as the Taylor series expansion are often convenient for theoretical work but less useful for practical applications. Truncated Chebyshev series, however, closely approximate the minimax polynomial.
One popular minimax approximation algorithm is the Remez algorithm.
|
https://en.wikipedia.org/wiki/Systems%20modeling%20language
|
The systems modeling language (SysML) is a general-purpose modeling language for systems engineering applications. It supports the specification, analysis, design, verification and validation of a broad range of systems and systems-of-systems.
SysML was originally developed by an open source specification project, and includes an open source license for distribution and use. SysML is defined as an extension of a subset of the Unified Modeling Language (UML) using UML's profile mechanism. The language's extensions were designed to support systems engineering activities.
Contrast with UML
SysML offers several systems engineering specific improvements over UML, which has been developed as a software modeling language. These improvements include the following:
SysML's diagrams express system engineering concepts better due to the removal of UML's software-centric restrictions and adds two new diagram types, requirement and parametric diagrams. The former can be used for requirements engineering; the latter can be used for performance analysis and quantitative analysis. Consequent to these enhancements, SysML is able to model a wide range of systems, which may include hardware, software, information, processes, personnel, and facilities.
SysML is a comparatively small language that is easier to learn and apply. Since SysML removes many of UML's software-centric constructs, the overall language is smaller both in diagram types and total constructs.
SysML allocation tables support common kinds of allocations. Whereas UML provides only limited support for tabular notations, SysML furnishes flexible allocation tables that support requirements allocation, functional allocation, and structural allocation. This capability facilitates automated verification and validation (V&V) and gap analysis.
SysML model management constructs support models, views, and viewpoints. These constructs extend UML's capabilities and are architecturally aligned with IEEE-Std-1471-2000 (IEEE
|
https://en.wikipedia.org/wiki/H%C3%B6lder%27s%20theorem
|
In mathematics, Hölder's theorem states that the gamma function does not satisfy any algebraic differential equation whose coefficients are rational functions. This result was first proved by Otto Hölder in 1887; several alternative proofs have subsequently been found.
The theorem also generalizes to the -gamma function.
Statement of the theorem
For every there is no non-zero polynomial such that
where is the gamma function.
For example, define by
Then the equation
is called an algebraic differential equation, which, in this case, has the solutions and — the Bessel functions of the first and second kind respectively. Hence, we say that and are differentially algebraic (also algebraically transcendental). Most of the familiar special functions of mathematical physics are differentially algebraic. All algebraic combinations of differentially algebraic functions are differentially algebraic. Furthermore, all compositions of differentially algebraic functions are differentially algebraic. Hölder’s Theorem simply states that the gamma function, , is not differentially algebraic and is therefore transcendentally transcendental.
Proof
Let and assume that a non-zero polynomial exists such that
As a non-zero polynomial in can never give rise to the zero function on any non-empty open domain of (by the fundamental theorem of algebra), we may suppose, without loss of generality, that contains a monomial term having a non-zero power of one of the indeterminates .
Assume also that has the lowest possible overall degree with respect to the lexicographic ordering For example,
because the highest power of in any monomial term of the first polynomial is smaller than that of the second polynomial.
Next, observe that for all we have:
If we define a second polynomial by the transformation
then we obtain the following algebraic differential equation for :
Furthermore, if is the highest-degree monomial term in , then the highest-degree monomial term i
|
https://en.wikipedia.org/wiki/Photostat%20machine
|
The Photostat machine, or Photostat, was an early projection photocopier created in the decade of the 1900s by the Commercial Camera Company, which became the Photostat Corporation. The "Photostat" name, which was originally a trademark of the company, became genericized, and was often used to refer to similar machines produced by the RetinalGraph Company.
History
Background
The growth of business during the industrial revolution created the need for a more efficient means of transcription than hand copying. Carbon paper was first used in the early 19th century. By the late 1840s copying presses were used to copy outgoing correspondence. One by one, other methods appeared. These included the "manifold writer," developed from Christoph Scheiner's pantograph and used by Mark Twain; copying baths; copying books; and roller copiers. Among the most significant of them was the Blue process in the early 1870s, which was mainly used to make blueprints of architectural and engineering drawings. Stencil duplicators (more commonly known as "Mimeograph machines") surfaced in 1874, and the Cyclostyle in 1891. All were manual and most involved messy fluids.
Retinal and Photostat machines
George C. Beidler of Oklahoma City founded the RetinalGraph Company in 1906 or 1907, producing the first photographic copying machines; he later moved the company to Rochester, New York in 1909 to be closer to the Haloid Company, his main source of photographic paper and chemicals.
The RetinalGraph Company was acquired by the Haloid Company in 1935. In 1948 Haloid purchased the rights to produce Chester Carlson's xerographic equipment and in 1958 the firm was reorganized to Haloid Xerox, Inc., which in 1961 was renamed Xerox Corporation. Haloid continued selling RetinalGraph machines into the 1960s.
The Photostat brand machine, differing in operation from the RetinalGraph but with the same purpose of the photographic copying of documents, was invented in Kansas City by Oscar T. Gregory in 1
|
https://en.wikipedia.org/wiki/Inverse%20beta%20decay
|
Inverse beta decay, commonly abbreviated to IBD, is a nuclear reaction involving an electron antineutrino scattering off a proton, creating a positron and a neutron. This process is commonly used in the detection of electron antineutrinos in neutrino detectors, such as the first detection of antineutrinos in the Cowan–Reines neutrino experiment, or in neutrino experiments such as KamLAND and Borexino. It is an essential process to experiments involving low-energy neutrinos (< 60 MeV) such as those studying neutrino oscillation, reactor neutrinos, sterile neutrinos, and geoneutrinos.
Reactions
Antineutrino induced
Inverse beta decay proceeds as
+ → + ,
where an electron antineutrino () interacts with a proton () to produce a positron () and a neutron (). The IBD reaction can only be initiated when the antineutrino possesses at least 1.806 MeV of kinetic energy (called the threshold energy). This threshold energy is due to a difference in mass between the products ( and ) and the reactants ( and ) and also slightly due to a relativistic mass effect on the antineutrino. Most of the antineutrino energy is distributed to the positron due to its small mass relative to the neutron. The positron promptly undergoes matter–antimatter annihilation after creation and yields a flash of light with energy calculated as
,
where 511 keV is the electron and positron rest energy, is the visible energy from the reaction, and is the antineutrino kinetic energy. After the prompt positron annihilation, the neutron undergoes neutron capture on an element in the detector, producing a delayed flash of 2.22 MeV if captured on a proton. The timing of the delayed capture is 200–300 microseconds after IBD initiation ( in the Borexino detector). The timing and spatial coincidence between the prompt positron annihilation and delayed neutron capture provides a clear IBD signature in neutrino detectors, allowing for discrimination from background. The IBD cross section is dependent
|
https://en.wikipedia.org/wiki/Euglena%20gracilis
|
Euglena gracilis is a freshwater species of single-celled alga in the genus Euglena. It has secondary chloroplasts, and is a mixotroph able to feed by photosynthesis or phagocytosis. It has a highly flexible cell surface, allowing it to change shape from a thin cell up to 100 µm long, to a sphere of approximately 20 µm. Each cell has two flagella, only one of which emerges from the flagellar pocket (reservoir) in the anterior of the cell, and can move by swimming, or by so-called "euglenoid" movement across surfaces. E. gracilis has been used extensively in the laboratory as a model organism, particularly for studying cell biology, biochemistry. Other areas of their use range from complex biological processes as photosynthesis, photoreception, phototaxic responses, nutritional studies and the relationship of molecular structure to the biological function of subcellular particles from a fundamental point of view. Euglena gracilis, is the most studied member of the Euglenaceae.
In recent years, Euglena has been found to be an excellent tool for investigations of fundamental biology and even as an aid in clinical diagnosis since they are used to measure vitamin B12 by bioassay.
Euglena has several chloroplasts surrounded by three membranes and with pyrenoids. These chloroplasts are of green algal origin. The main storage product is paramylon, a β-1,3 polymer of glucose stored in the form of granules in the cytoplasm. A red eyespot (stigma) is located near the base of the reservoir and this filters the light and focuses it on the paraflagellar body, and is involved in the phototaxis of this alga.
Taxonomy
A morphological and molecular study of the Euglenozoa put E. gracilis in close kinship with the species Khawkinea quartana, with Peranema trichophorum basal to both, although a later molecular analysis showed that E. gracilis was, in fact, more closely related to Astasia longa than to certain other species recognized as Euglena. The transcriptome of E. gracilis wa
|
https://en.wikipedia.org/wiki/Regius%20Professor%20of%20Zoology
|
The Regius Chair of Zoology is a Regius Professorship at the University of Glasgow. It was founded in 1807 by George III of the United Kingdom as the Regius Chair of Natural History. In 1903, when the Chair of Geology was founded at Glasgow University, the title was changed to Zoology.
Regius Professors of Natural History/Regius Professors of Zoology
Lockhart Muirhead MA LLD (1807)
William Couper MA MD (1829)
Henry Darwin Rogers MA LLD (1857)
John Young MD (1866)
Sir John Graham Kerr MA LLD FRS (August 1902)
Edward Hindle MA PhD ScD FRS (1935)
Charles Maurice Yonge CBE PhD DSc FRS (1944)
David Richmond Newth BSc PhD (1965)
Keith Vickerman PhD DSc FRSE FRS (1984-1998)
1998 - 2013 vacant
2013 - now Pat Monaghan
|
https://en.wikipedia.org/wiki/Fasciculus%20Medicinae
|
Fasciculus Medicinae is a "bundle" of six independent and quite different medieval medical treatises. The collection, which existed only in two manuscripts (handwritten copies), was first printed in 1491 in Latin and came out in numerous editions over the next 25 years. Johannes de Ketham, the German physician routinely associated with the Fasciculus, was neither the author nor even the original compiler but merely an owner of one of the manuscripts. The topics of the treatises cover a wide spectrum of medieval European medical knowledge and technique, including uroscopy, astrology, bloodletting, the treatment of wounds, plague, anatomical dissection, and women’s health. The book is remarkable as the first illustrated medical work to appear in print; notable illustrations include: a urine chart, a diagram of the veins for phlebotomy, a pregnant woman, Wound Man, Disease Man and Zodiac Man. In 1495, it appeared in Italian under the title Fasiculo de Medicina.
The ten handsome full-page woodcut illustrations influenced artists for some time – even as late as 1751 when the last of William Hogarth's Four Stages of Cruelty seems to borrow from the dissection scene (above).
|
https://en.wikipedia.org/wiki/AMX192
|
AMX192 (often referred to simply as AMX) is an analog lighting communications protocol used to control stage lighting. It was developed by Strand Century in the late 1970s. Originally, AMX192 was only capable of controlling 192 discrete channels of lighting. Later, multiple AMX192 streams were supported by some lighting desks. AMX192 has mostly been replaced in favour of DMX, and is typically only found in legacy hardware.
History
The name AMX192 is derived from analog multiplexing and the maximum number of controllable lighting channels (192). AMX was developed to address a significant problems in controlling dimmers. For many years, in order to send a control signal from a lighting control unit to the dimmer units, the only method available was to provide a dedicated wire from the control unit to each dimmer (analogue control) where the voltage present on the wire was varied by the control unit to set the output level of the dimmer. In the late 1970s, the AMX192 serial analogue multiplexing standard was developed in the US, permitting one cable to control several dimmers.
At about the same time, D54 was developed in the United Kingdom, and differed from AMX192 in that it used an embedded clocking scheme. AMX192 used a separate differential clock with a driver circuit similar to RS-485, but current limited on each leg with 100Ω resistors.
See also
Dimmer
Lighting control console
Lighting control system
DMX512
RDM
External links
Strand Lighting Corporate
University of Exeter - Strand Archive
Stage lighting
Network protocols
|
https://en.wikipedia.org/wiki/Internetowa%20encyklopedia%20PWN
|
Internetowa encyklopedia PWN (Polish for Internet PWN Encyclopedia) is a free online Polish-language encyclopedia published by Wydawnictwo Naukowe PWN. It contains some 80,000 entries and 5,000 illustrations.
External links
Internetowa encyklopedia PWN
Online encyclopedias
Polish online encyclopedias
Polish Scientific Publishers PWN books
|
https://en.wikipedia.org/wiki/Perpetual%20access
|
Perpetual access is the stated continuous access of licensed electronic material after is it no longer accessible through an active paid subscription either through the library or publisher action. In many cases, the two parties involved in the license agree that it is necessary for the license to retain access to these materials after the license has lapsed. Other terms for perpetual access or similar trains of thought are ‘post-cancellation access’ and ‘continuing access.'
In the licensing of software products, a perpetual license means that a software application is sold on a one-time basis and the licensee can then use a copy of the software forever. The license holder has indefinite access to a specific version of a software program by paying for it only once.
Perpetual access is a term that is used within the library community to describe the ability to retain access to electronic journals after the contractual agreement for these materials has passed. Typically when a library licenses access to an electronic journal, the journal's content remains in the possession of the licensor. The library often purchases the rights to all back issues as well as new issues. When the license expires, access to all the journal's contents is lost. In a typical print model, the library purchases the journals and retains them for the duration of the contract but also after the contract expires. In order to retain access to journals that were released during the term of a license for digital electronic journals, the library must obtain perpetual access rights.
The ability to maintain perpetual access can be seen in the shift from print to electronic material, as apparent in both user demand and advantages of non-print material. Electronic materials rely on a relationship between library and publisher, with a distinct dynamic over the publisher's control of the licensed material. This in turn causes issues when the paid for subscription with a publisher ends and the use of
|
https://en.wikipedia.org/wiki/Zygomatico-orbital%20foramina
|
The zygomatico-orbital foramina are two canals in the skull, that allow nerves to pass through. The orifices are seen on the orbital process of the zygomatic bone.
One of these canals opens into the temporal fossa, the other on the malar surface of the bone.
The former transmits the zygomaticotemporal, the latter the zygomaticofacial nerve.
|
https://en.wikipedia.org/wiki/Directory%20harvest%20attack
|
A directory harvest attack (DHA) is a technique used by spammers in an attempt to find valid/existent e-mail addresses at a domain by using brute force. The attack is usually carried out by way of a standard dictionary attack, where valid e-mail addresses are found by brute force guessing valid e-mail addresses at a domain using different permutations of common usernames. These attacks are more effective for finding e-mail addresses of companies since they are likely to have a standard format for official e-mail aliases (i.e. jdoe@example.domain, johnd@example.domain, or johndoe@example.domain).
There are two main techniques for generating the addresses that a DHA targets. In the first, the spammer creates a list of all possible combinations of letters and numbers up to a maximum length and then appends the domain name. This would be described as a standard brute force attack. This technique would be impractical for usernames longer than 5-7 characters. For example, one would have to try 368 (nearly 3 trillion) e-mail addresses to exhaust all 8-character sequences.
The other, more targeted technique, is to create a list that combines common first name and surnames and initials (as in the example above). This would be considered a standard dictionary attack when guessing usernames for e-mail addresses. The success of a directory harvest attack relies on the recipient e-mail server rejecting e-mail sent to invalid recipient e-mail addresses during the Simple Mail Transfer Protocol (SMTP) session. Any addresses to which email is accepted are considered valid and are added to the spammer's list (which is commonly sold between spammers). Although the attack could also rely on Delivery Status Notifications (DSNs) to be sent to the sender address to notify of delivery failures, directory harvest attacks likely don't use a valid sender e-mail address.
The actual e-mail message generated to the recipient addresses will usually be a short random phrase such as "hello", s
|
https://en.wikipedia.org/wiki/Foramina%20of%20Scarpa
|
In the maxilla, occasionally two additional canals are present in the middle line of the palatine process; they are termed the foramina of Scarpa, and when present transmit the nasopalatine nerves, the left passing through the anterior, and the right through the posterior canal.
See also
Antonio Scarpa – anatomist
|
https://en.wikipedia.org/wiki/Stain
|
A stain is a discoloration that can be clearly distinguished from the surface, material, or medium it is found upon. They are caused by the chemical or physical interaction of two dissimilar materials. Accidental staining may make materials appear used, degraded or permanently unclean. Intentional staining is used in biochemical research and for artistic effect, such as wood staining, rust staining and stained glass.
Types
There can be intentional stains (such as wood stains or paint), indicative stains (such as food coloring dye, or adding a substance to make bacteria visible under a microscope), natural stains (such as rust on iron or a patina on bronze), and accidental stains such as ketchup and synthetic oil on clothing.
Different types of material can be stained by different substances, and stain resistance is an important characteristic in modern textile engineering.
Formation
The primary method of stain formation is surface stains, where the staining substance is spilled out onto the surface or material and is trapped in the fibers, pores, indentations, or other capillary structures on the surface. The material that is trapped coats the underlying material, and the stain reflects backlight according to its own color. Applying paint, spilled food, and wood stains are of this nature.
A secondary method of stain involves a chemical or molecular reaction between the material and the staining material. Many types of natural stains fall into this category.
Finally, there can also be molecular attraction between the material and the staining material, involving being held in a covalent bond and showing the color of the bound substance.
Properties
In many cases, stains are affected by heat and may become reactive enough to bond with the underlying material. Applied heat, such as from ironing, dry cleaning or sunlight, can cause a chemical reaction on an otherwise removable stain, turning it into a chemical.
Removal
Various laundry techniques exist to attempt t
|
https://en.wikipedia.org/wiki/Mandibular%20fossa
|
The mandibular fossa, also known as the glenoid fossa in some dental literature, is the depression in the temporal bone that articulates with the mandible.
Structure
In the temporal bone, the mandibular fossa is bounded anteriorly by the articular tubercle and posteriorly by the tympanic portion of the temporal bone, which separates it from the external acoustic meatus. The fossa is divided into two parts by a narrow slit, the petrotympanic fissure (Glaserian fissure). It is concave in shape to receive the condyloid process of the mandible.
Development
The mandibular fossa develops from condylar cartilage. This may be stimulated by SOX9 or ALK2, as has been seen in mouse models.
Function
The condyloid process of the mandible articulates with the temporal bone of the skull at the mandibular fossa.
Clinical significance
Problems with morphogenesis during embryonic development can lead to the mandibular fossa not forming. This may be caused by mutations to SOX9 or ALK2.
If the mandibular fossa is very shallow, this can cause problems with the strength of the temporomandibular joint. This can lead to easy subluxation of the joint and trismus (lock jaw). Deformation of the mandibular fossa, often part of temporomandibular dysplasia, causes similar problems in dogs. This may resolve spontaneously, or require surgery.
History
The mandibular fossa is also known as the glenoid fossa in some dental literature.
Other animals
The mandibular fossa is a feature of the skulls of various other animals, including dogs.
See also
Temporomandibular joint
|
https://en.wikipedia.org/wiki/Alveolar%20canals
|
The alveolar canals are apertures in the center of the infratemporal surface of the maxilla. The alveolar canals transmit the posterior superior alveolar vessels and nerves.
|
https://en.wikipedia.org/wiki/Condyloid%20fossa
|
Behind either condyle of the lateral parts of occipital bone is a depression, the condyloid fossa (or condylar fossa), which receives the posterior margin of the superior facet of the atlas when the head is bent backward; the floor of this fossa is sometimes perforated by the condyloid canal, through which an emissary vein passes from the transverse sinus.
Additional images
See also
Occipital condyle
Atlas
|
https://en.wikipedia.org/wiki/Sphenoidal%20process%20of%20palatine%20bone
|
The sphenoidal process of palatine bone is a thin, superomedially directed plate of bone. It is smaller and more inferior compared to the orbital process of palatine bone.
Anatomy
Surfaces
The superior surface articulates with the root of the pterygoid process and the under surface of the sphenoidal concha, its medial border reaching as far as the ala of the vomer; it presents a groove which contributes to the formation of the pharyngeal canal.
The medial surface is concave, and forms part of the lateral wall of the nasal cavity.
The lateral surface is divided into an articular and a non-articular portion: the former is rough, for articulation with the medial pterygoid plate; the latter is smooth, and forms part of the pterygopalatine fossa.
Borders
The anterior border forms the posterior boundary of the sphenopalatine notch.
The posterior border, serrated at the expense of the outer table, articulates with the vaginal process of the medial pterygoid plate of sphenoid bone.
The medial border articulates with ala of vomer.
The orbital and sphenoidal processes are separated from one another by the sphenopalatine notch. Sometimes the two processes are united above, and form between them a complete foramen, or the notch may be crossed by one or more spicules of bone, giving rise to two or more foramina.
Additional images
|
https://en.wikipedia.org/wiki/Orbital%20process%20of%20palatine%20bone
|
The orbital process of the palatine bone is placed on a higher level than the sphenoidal, and is directed upward and lateralward from the front of the vertical part, to which it is connected by a constricted neck. It presents five surfaces, which enclose an air cell. Of these surfaces, three are articular and two non-articular.
The articular surfaces are:
the anterior or maxillary, directed forward, lateralward, and downward, of an oblong form, and rough for articulation with the maxilla
the posterior or sphenoidal, directed backward, upward, and medialward; it presents the opening of the air cell, which usually communicates with the sphenoidal sinus; the margins of the opening are serrated for articulation with the sphenoidal concha
the medial or ethmoidal, directed forward, articulates with the labyrinth of the ethmoid.
In some cases the air cell opens on this surface of the bone and then communicates with the posterior ethmoidal cells. More rarely it opens on both surfaces, and then communicates with the posterior ethmoidal cells and the sphenoidal sinus.
The non-articular surfaces are:
the superior or orbital, directed upward and lateralward; it is triangular in shape, and forms the back part of the floor of the orbit; and
the lateral, of an oblong form, directed toward the pterygopalatine fossa; it is separated from the orbital surface by a rounded border, which enters into the formation of the inferior orbital fissure.
Additional images
|
https://en.wikipedia.org/wiki/Pyramidal%20process%20of%20palatine%20bone
|
The pyramidal process of the palatine bone projects backward and lateralward from the junction of the horizontal and vertical parts, and is received into the angular interval between the lower extremities of the pterygoid plates.
On its posterior surface is a smooth, grooved, triangular area, limited on either side by a rough articular furrow. The furrows articulate with the pterygoid plates, while the grooved intermediate area completes the lower part of the pterygoid fossa and gives origin to a few fibers of the Pterygoideus internus.
The anterior part of the lateral surface is rough, for articulation with the tuberosity of the maxilla; its posterior part consists of a smooth triangular area which appears, in the articulated skull, between the tuberosity of the maxilla and the lower part of the lateral pterygoid plate, and completes the lower part of the infratemporal fossa.
On the base of the pyramidal process, close to its union with the horizontal part, are the lesser palatine foramina for the transmission of the posterior and middle palatine nerves.
Additional images
|
https://en.wikipedia.org/wiki/Perpendicular%20plate%20of%20palatine%20bone
|
The perpendicular plate of palatine bone is the vertical part of the palatine bone, and is thin, of an oblong form, and presents two surfaces and four borders.
Surfaces
The nasal surface exhibits at its lower part a broad, shallow depression, which forms part of the inferior meatus of the nose. Immediately above this is a well-marked horizontal ridge, the conchal crest, for articulation with the inferior nasal concha; still higher is a second broad, shallow depression, which forms part of the middle meatus, and is limited above by a horizontal crest less prominent than the inferior, the ethmoidal crest, for articulation with the middle nasal concha. Above the ethmoidal crest is a narrow, horizontal groove, which forms part of the superior meatus.
The maxillary surface is rough and irregular throughout the greater part of its extent, for articulation with the nasal surface of the maxilla; its upper and back part is smooth where it enters into the formation of the pterygopalatine fossa; it is also smooth in front, where it forms the posterior part of the medial wall of the maxillary sinus. On the posterior part of this surface is a deep vertical groove, converted into the pterygopalatine canal, by articulation with the maxilla; this canal transmits the descending palatine vessels, and the anterior palatine nerve.
Borders
The anterior border is thin and irregular; opposite the conchal crest is a pointed, projecting lamina, the maxillary process, which is directed forward, and closes in the lower and back part of the opening of the maxillary sinus.
The posterior border presents a deep groove, the edges of which are serrated for articulation with the medial pterygoid plate of the sphenoid. This border is continuous above with the sphenoidal process; below it expands into the pyramidal process.
The superior border supports the orbital process in front and the sphenoidal process behind. These processes are separated by the sphenopalatine notch, which is converted
|
https://en.wikipedia.org/wiki/Horizontal%20plate%20of%20palatine%20bone
|
The horizontal plate of palatine bone is a quadrilateral part of the palatine bone, and has two surfaces and four borders.
Surfaces
The superior surface, concave from side to side, forms the back part of the floor of the nasal cavity.
The inferior surface, slightly concave and rough, forms, with the corresponding surface of the opposite bone, the posterior fourth of the hard palate. Near its posterior margin may be seen a more or less marked transverse ridge for the attachment of part of the aponeurosis of the tensor veli palatini.
Borders
The anterior border is serrated. It articulates with the palatine process of maxilla.
The posterior border is concave, free, and serves for the attachment of the soft palate. Its medial end is sharp and pointed, and, when united with that of the opposite bone, forms a projecting process, the posterior nasal spine for the attachment of the musculus uvulae.
The lateral border is united with the lower margin of the perpendicular plate, and is grooved by the lower end of the greater palatine canal.
The medial border, the thickest, is serrated for articulation with its fellow of the opposite side; its superior edge is raised into a ridge, which, united with the ridge of the opposite bone, forms the nasal crest for articulation with the posterior part of the lower edge of the vomer.
Additional images
|
https://en.wikipedia.org/wiki/Scaphoid%20fossa
|
In the pterygoid processes of the sphenoid, above the pterygoid fossa is a small, oval, shallow depression, the scaphoid fossa, which gives origin to the Tensor veli palatini.
It is not the same as and has to be distinguished from the scaphoid fossa of the external ear or pinna.
|
https://en.wikipedia.org/wiki/Pterygoid%20fossa
|
The pterygoid fossa is an anatomical term for the fossa formed by the divergence of the lateral pterygoid plate and the medial pterygoid plate of the sphenoid bone.
Structure
The lateral and medial pterygoid plates (of the pterygoid process of the sphenoid bone) diverge behind and enclose between them a V-shaped fossa, the pterygoid fossa. This fossa faces posteriorly, and contains the medial pterygoid muscle and the tensor veli palatini muscle.
See also
Pterygoid fovea
Scaphoid fossa
Pterygoid process
|
https://en.wikipedia.org/wiki/External%20occipital%20protuberance
|
Near the middle of the squamous part of occipital bone is the external occipital protuberance, the highest point of which is referred to as the inion. The inion is the most prominent projection of the protuberance which is located at the posterioinferior (rear lower) part of the human skull. The nuchal ligament and trapezius muscle attach to it.
The inion (ἰνίον, iníon, Greek for the occipital bone) is used as a landmark in the 10-20 system in electroencephalography (EEG) recording. Extending laterally from it on either side is the superior nuchal line, and above it is the faintly marked highest nuchal line.
A study of 16th-century Anatolian remains showed that the external occipital protuberance statistically tends to be less pronounced in female remains.
Additional images
See also
Internal occipital protuberance
Occipital bun
|
https://en.wikipedia.org/wiki/Anterior%20nasal%20spine
|
The anterior nasal spine, or anterior nasal spine of maxilla, is a bony projection in the skull that serves as a cephalometric landmark. The anterior nasal spine is the projection formed by the fusion of the two maxillary bones at the intermaxillary suture. It is placed at the level of the nostrils, at the uppermost part of the philtrum. It rarely fractures.
Additional images
See also
Posterior nasal spine
|
https://en.wikipedia.org/wiki/L%E1%BA%A1c%20Long%20Qu%C3%A2n
|
Lạc Long Quân (Chữ Hán:貉龍君; "Dragon King of Lạc"; also called Sùng Lãm 崇纜) is an ancient king of the Hồng Bàng dynasty of ancient Vietnam. Quân was the son of Kinh Dương Vương, the king of Xích Quỷ. He is the main figure in the Vietnamese creation myth of .
According to the myth, Lạc Long Quân married Âu Cơ, a mountain goddess. She gives birth to a sac containing 100 eggs from which 100 children were born; this is the origin of the Vietnamese peoples. One day Lạc Long Quân told Âu Cơ: "I am descended from dragons, you from goddess. We are as incompatible as water is with fire. So we cannot continue in harmony." This said, the husband and wife parted. The man went to the seawards with 50 of their children, while his wife went to the mountainous region with the other half of the clan. The eldest son, who followed his mother, later installed himself as Quân's successor.
Genealogy
Lạc Long Quân's father was Kinh Dương Vương and Lạc Long Quân's mother is Thần Long.
In Vietnamese literature
The books (from the 15th century) and ("Wonders plucked from the dust of Linh-nam", from the 14th century) mention the legend with Âu Cơ. Ngô Sĩ Liên commented on the somewhat primitive nature of the relationship between the two progenitors, given that Lạc's father Kinh Dương Vương and Âu's grandfather Đế Nghi were brothers.
Mythology
Slaying of the Ngư tinh
During Lạc Long Quân's time, the people of Van Lang was still undeveloped and isolated. In the Eastern sea, there appears a giant Fish called Ngư Tinh (, Vietnamese for "fish monster" or "fish spirit"). This fish has lived for many centuries and had a mouth so big it could swallow an entire ship containing 10 fisherman in a single gulp. Whenever the fish swim, waves would reach for the sky, drowning many ships unfortunate enough to be caught in its path, and all the people passing through the area would become the fish's next meal. Ngư Tinh lives in a big cave under the sea, above the cave is a huge mountain which divides
|
https://en.wikipedia.org/wiki/Posterior%20nasal%20spine
|
The posterior nasal spine is part of the horizontal plate of the palatine bone of the skull. It is found at the medial end of its posterior border. It is paired with the corresponding palatine bone to form a solid spine. It is the attachment of the uvula muscle.
Structure
The posterior nasal spine is found at the medial end of the posterior border of the horizontal plate of the palatine bone of the skull.
Function
The posterior nasal spine is the attachment of the uvula muscle.
Clinical applications
The posterior nasal spine is an important cephalometric landmark.
Additional images
See also
anterior nasal spine
|
https://en.wikipedia.org/wiki/Cochlear%20aqueduct
|
Medial to the opening for the carotid canal and close to its posterior border, in front of the jugular fossa, is a triangular depression; at the apex of this is a small opening, the aquaeductus cochleae (or cochlear aqueduct, or aqueduct of cochlea), which lodges a tubular prolongation of the dura mater establishing a communication between the perilymphatic space and the subarachnoid space, and transmits a vein from the cochlea to join the internal jugular vein.
Additional images
|
https://en.wikipedia.org/wiki/Sulcus%20of%20auditory%20tube
|
The lateral half of the great wing of the sphenoid bone articulates, by means of a synchondrosis, with the petrous part of the temporal bone. Between these two bones on the under surface of the skull, is a furrow, the 'sulcus of auditory tubule, for the lodgement of the cartilaginous part of the auditory tube.
|
https://en.wikipedia.org/wiki/Parietal%20eminence
|
The parietal eminence (parietal tuber, parietal tuberosity) is a convex, smooth eminence on the external surface of the parietal bone of the skull. It is the site where intramembranous ossification of the parietal bone begins during embryological development. It tends to be slightly more prominent in women than in men, so may be used to help to identify the sex of a skull.
Additional images
|
https://en.wikipedia.org/wiki/Parietal%20foramina
|
A parietal foramen is an opening in the skull for the parietal emissary vein, which drains into the superior sagittal sinus. Occasionally, a small branch of the occipital artery can also pass through it. It is located at the back part of the parietal bone, close to the upper or sagittal border. It is not always present, and its size varies considerably. Parietal foramina tend to be symmetrical, with the same number on each side.
See also
Foramina of skull
|
https://en.wikipedia.org/wiki/Articular%20tubercle
|
The articular tubercle (eminentia articularis) is a bony eminence on the temporal bone in the skull. It is a rounded eminence of the anterior root of the posterior end of the outer surface of the squama temporalis. This tubercle forms the front boundary of the mandibular fossa, and in the fresh state is covered with cartilage.
The mandibular condyle normally moves over the articular tubercle during physiologic maximal opening of the jaw. The articular tubercle is the site of attachment of the lateral ligament of the temporomandibular joint.
|
https://en.wikipedia.org/wiki/Infratemporal%20crest
|
The lateral surface of the greater wing of the sphenoid is convex, and divided by a transverse ridge, the infratemporal crest, into two portions.
The superior or temporal portion, convex from above downward, concave from before backward, forms a part of the temporal fossa, and gives attachment to the Temporalis; the inferior or infratemporal, smaller in size and concave, enters into the formation of the infratemporal fossa, and, together with the infratemporal crest, affords attachment to the Pterygoideus externus.
Additional images
|
https://en.wikipedia.org/wiki/Suprameatal%20triangle
|
In the temporal bone, between the posterior wall of the external acoustic meatus and the posterior root of the zygomatic process is the area called the suprameatal triangle, suprameatal pit, mastoid fossa, foveola suprameatica, or Macewen's triangle, through which an instrument may be pushed into the mastoid antrum.
In the adult, the antrum lies approximately 1.5 to 2 cm deep to the suprameatal triangle. This is an important landmark when performing a cortical mastoidectomy.
The triangle lies deep to the cymba conchae.
|
https://en.wikipedia.org/wiki/Petrotympanic%20fissure
|
The petrotympanic fissure (also known as the squamotympanic fissure or the glaserian fissure) is a fissure in the temporal bone that runs from the temporomandibular joint to the tympanic cavity.
The mandibular fossa is bounded, in front, by the articular tubercle; behind, by the tympanic part of the bone, which separates it from the external acoustic meatus; it is divided into two parts by a narrow slit, the petrotympanic fissure.
It opens just above and in front of the ring of bone into which the tympanic membrane is inserted; in this situation it is a mere slit about 2 mm. in length. It lodges the anterior process and anterior ligament of the malleus, and gives passage to the anterior tympanic branch of the internal maxillary artery.
Eponym
It is also known as the "Glaserian fissure", after Johann Glaser.
Contents
The contents of the fissure include communications of cranial nerve VII to the infratemporal fossa. A branch of cranial nerve VII, the chorda tympani, runs through the fissure to join with the lingual nerve providing special sensory (taste) innervation to the tongue. Anterior tympanic artery and tympanic veins also pass through the structure. Petrotympanic fissure contains some of the fibers of the anterior ligament of malleus, which run on the base of skull and eventually attach onto the spine of sphenoid bone.
See also
Chorda tympani
Petrosquamous suture
|
https://en.wikipedia.org/wiki/Pharyngeal%20tubercle
|
The pharyngeal tubercle is a part of the occipital bone of the head and neck. It is located on the lower surface of the basilar part of occipital bone. It is the site of attachment of the pharyngeal raphe.
Structure
The pharyngeal tubercle is located on the inferior surface of the basilar part of occipital bone. This about 1 cm anterior to the foramen magnum.
Attachments
The pharyngeal tubercle gives attachment to the pharyngeal raphe and, thereby, the superior pharyngeal constrictor muscle which forms it.
See also
Clivus (anatomy)
|
https://en.wikipedia.org/wiki/Ruth%E2%80%93Aaron%20pair
|
In mathematics, a Ruth–Aaron pair consists of two consecutive integers (e.g., 714 and 715) for which the sums of the prime factors of each integer are equal:
714 = 2 × 3 × 7 × 17,
715 = 5 × 11 × 13,
and
2 + 3 + 7 + 17 = 5 + 11 + 13 = 29.
There are different variations in the definition, depending on how many times to count primes that appear multiple times in a factorization.
The name was given by Carl Pomerance for Babe Ruth and Hank Aaron, as Ruth's career regular-season home run total was 714, a record which Aaron eclipsed on April 8, 1974, when he hit his 715th career home run. Pomerance was a mathematician at the University of Georgia at the time Aaron (a member of the nearby Atlanta Braves) broke Ruth's record, and the student of one of Pomerance's colleagues noticed that the sums of the prime factors of 714 and 715 were equal.
Examples
If only distinct prime factors are counted, the first few Ruth–Aaron pairs are:
(5, 6), (24, 25), (49, 50), (77, 78), (104, 105), (153, 154), (369, 370), (492, 493), (714, 715), (1682, 1683), (2107, 2108)
(The lesser of each pair is listed in ).
Counting repeated prime factors (e.g., 8 = 2×2×2 and 9 = 3×3 with 2+2+2 = 3+3), the first few Ruth–Aaron pairs are:
(5, 6), (8, 9), (15, 16), (77, 78), (125, 126), (714, 715), (948, 949), (1330, 1331)
(The lesser of each pair is listed in ).
The intersection of the two lists begins:
(5, 6), (77, 78), (714, 715), (5405, 5406).
(The lesser of each pair is listed in ).
Any Ruth–Aaron pair of square-free integers belongs to both lists with the same sum of prime factors. The intersection also contains pairs that are not square-free, for example (7129199, 7129200) = (7×112×19×443, 24×3×52×13×457). Here 7+11+19+443 = 2+3+5+13+457 = 480, and also 7+11+11+19+443 = 2+2+2+2+3+5+5+13+457 = 491.
Density
Ruth-Aaron pairs are sparse (that is, they have density 0). This was conjectured by Nelson et al. in 1974 and proven in 1978 by Paul Erdős and Pomerance.
Ruth–Aaron triplets
Ruth–
|
https://en.wikipedia.org/wiki/Suprameatal%20spine
|
The inner end of the external acoustic meatus is closed, in the recent state, by the tympanic membrane; the upper limit of its outer orifice is formed by the posterior root of the zygomatic process, immediately below which there is sometimes seen a small spine, the suprameatal spine also called the spine of Henle, situated at the upper and posterior part of the orifice.
|
https://en.wikipedia.org/wiki/Piriform%20aperture
|
The piriform aperture, pyriform aperture, or anterior nasal aperture, is a pear-shaped opening in the human skull.
Its long axis is vertical, and narrow end upward; in the recent state it is much contracted by the lateral nasal cartilage and the greater and lesser alar cartilages of the nose.
It is bounded above by the inferior borders of the nasal bones; laterally by the thin, sharp margins which separate the anterior from the nasal surfaces of the maxilla; and below by the same borders, where they curve medialward to join each other at the anterior nasal spine.
|
https://en.wikipedia.org/wiki/Ethmoidal%20spine
|
The superior surface of the body of the sphenoid bone (Fig. 145) presents in front a prominent spine, the ethmoidal spine, for articulation with the cribriform plate of the ethmoid; behind this is a smooth surface slightly raised in the middle line, and grooved on either side for the olfactory lobes of the brain.
Additional images
|
https://en.wikipedia.org/wiki/Posterior%20lacrimal%20crest
|
The posterior lacrimal crest is a vertical bony ridge on the orbital surface of the lacrimal bone. It divides the bone into two parts. It gives origin to the lacrimal part of the orbicularis oculi muscle.
Structure
The posterior lacrimal crest is a vertical bony ridge on the orbital (lateral) surface of the lacrimal bone. It divides the lacrimal bone into two parts. It is quite thin and fragile in most people.
The lacrimal groove is in front of this crest. The inner margin of it unites with the frontal process of the maxilla to complete the fossa for the lacrimal sac. The portion of the lacrimal bone behind the posterior lacrimal crest is smooth, and forms part of the medial wall of the orbit. The lacrimal crest ends below in the lacrimal hamulus (a small hook-like projection), which articulates with the lacrimal tubercle of the maxilla.
Relations
The posterior lacrimal crest is just behind the lacrimal sac, and its upper part lodges the lacrimal sac. The lower part lodges the nasolacrimal duct. Horner's muscle, part of the orbicularis oris muscle, inserts between 2 mm and 4 mm from the posterior lacrimal crest. Together with the thicker and more prominent anterior lacrimal crest, it forms the fossa for the lacrimal sac.
Variation
In most people, the posterior lacrimal crest is fairly prominent. However, in around 20% of people, it is fairly shallow. In contrast, the anterior lacrimal crest is almost always very prominent.
Function
The posterior lacrimal crest gives origin to the lacrimal part of the orbicularis oculi muscle. It also helps to protect the lacrimal sac.
Clinical significance
The posterior lacrimal crest may be vulnerable to avulsion fractures. It is generally quite thin and fragile. 25% of such avulsion fractures are related to a Le Fort III skull fracture.
Additional images
See also
Anterior lacrimal crest
|
https://en.wikipedia.org/wiki/Anterior%20lacrimal%20crest
|
The anterior lacrimal crest is a bony projection on the frontal process of the maxilla. It creates the lateral margin of the lacrimal sac fossa and is continuous with the orbital margin. The medial palpebral ligament is attached to anterior lacrimal crest. It is an important structure to avoid damaging during rhinoplasty.
Structure
The anterior lacrimal crest is a bony projection on the frontal process of the maxilla in the skull. It reaches the junction between the maxilla and the lacrimal bone.
At its junction with the orbital surface is a small tubercle, the lacrimal tubercle, which serves as a guide to the position of the lacrimal sac.
The anterior lacrimal crest is much thicker and stronger than the posterior lacrimal crest. It is one of the thickest parts of the orbit. It is nearly always quite prominent, whilst the posterior lacrimal crest may be less prominent in some people.
Relations
The lacrimal sac is directly behind the anterior lacrimal crest, which protects it as part of the fossa for the lacrimal sac.
Function
The anterior lacrimal crest is the site of insertion of the medial palpebral ligament. Some consider this a tendon of the orbicularis oris muscle. The anterior lacrimal crest also protects the lacrimal sac.
Clinical significance
Avulsion
The anterior lacrimal crest may be vulnerable to an avulsion fracture due to its connection to the medial palpebral ligament.
Rhinoplasty
The anterior lacrimal crest is vulnerable to damage during osteotomy performed during rhinoplasty, a common plastic surgery. It lies approximately 5 mm from the osteotomy incision line.
See also
Posterior lacrimal crest
Additional images
|
https://en.wikipedia.org/wiki/List%20mining
|
List mining can be defined as the use, for purposes of scientific research, of messages sent to Internet-based electronic mailing lists. List mining raises novel issues in Internet research ethics. These ethical issues are especially important for health related lists. Some questions that need to be considered by a Research Ethics Committee (or an Institutional Review Board) when reviewing research proposals that involve list mining include these:
Are participants in mailing lists "research subjects"?
Should those participants in a health related electronic mailing list who were the original sources of messages sent to such lists be regarded as "research subjects"? If so, then several ethical issues need to be considered. These include those pertaining to privacy, informed consent, whether the research is intrusive and has potential for harm, and whether the list should be perceived as "private" or "public" space.
Are participants in mailing lists "published authors"?
Should those who were the sources of messages sent to such lists be regarded as "published authors"? Or, perhaps, as "amateur authors"?
If so, there are issues of copyright and proper attribution to be considered if messages sent to such lists are cited verbatim. Even short excerpts from such messages raise such issues.
Are participants in mailing lists "members of a community"?
Participants on mailing lists such as electronic support groups may regard themselves as members of an online "community". Are they?
To provide an answer to this question, characteristics of various types of communities need to be defined and considered. For example, if one defining characteristic of a community is "self-identification as community", then virtual groups often have this characteristic. However, if "geographic localization" or "legitimate political authority" are considered to be other defining characteristics of a community, then virtual groups rarely or never possess this characteristic.
Of particular imp
|
https://en.wikipedia.org/wiki/Critical%20point%20%28set%20theory%29
|
In set theory, the critical point of an elementary embedding of a transitive class into another transitive class is the smallest ordinal which is not mapped to itself.
Suppose that is an elementary embedding where and are transitive classes and is definable in by a formula of set theory with parameters from . Then must take ordinals to ordinals and must be strictly increasing. Also . If for all and , then is said to be the critical point of .
If is V, then (the critical point of ) is always a measurable cardinal, i.e. an uncountable cardinal number κ such that there exists a -complete, non-principal ultrafilter over . Specifically, one may take the filter to be . Generally, there will be many other <κ-complete, non-principal ultrafilters over . However, might be different from the ultrapower(s) arising from such filter(s).
If and are the same and is the identity function on , then is called "trivial". If the transitive class is an inner model of ZFC and has no critical point, i.e. every ordinal maps to itself, then is trivial.
|
https://en.wikipedia.org/wiki/TestDisk
|
TestDisk is a free and open-source data recovery utility that helps users recover lost partitions or repair corrupted filesystems. TestDisk can collect detailed information about a corrupted drive, which can then be sent to a technician for further analysis. TestDisk supports DOS, Microsoft Windows (i.e. NT 4.0, 2000, XP, Server 2003, Server 2008, Vista, Windows 7, Windows 8.1, Windows 10), Linux, FreeBSD, NetBSD, OpenBSD, SunOS, and MacOS. TestDisk handles non-partitioned and partitioned media. In particular, it recognizes the GUID Partition Table (GPT), Apple partition map, PC/Intel BIOS partition tables, Sun Solaris slice and Xbox fixed partitioning scheme. TestDisk uses a command line user interface. TestDisk can recover deleted files with 97% accuracy.
Features
TestDisk can recover deleted partitions, rebuild partition tables or rewrite the master boot record (MBR).
Partition recovery
TestDisk retrieves the LBA size and CHS geometry of attached data storage devices (i.e. hard disks, memory cards, USB flash drives, and virtual disk images) from the BIOS or the operating system. The geometry information is required for a successful recovery. TestDisk reads sectors on the storage device to determine if the partition table or filesystem on it requires repair (see next section).
TestDisk is able to recognize the following partition table formats:
Apple partition map
GUID Partition Table
Humax
PC/Intel Partition Table (master boot record)
Sun Solaris slice
Xbox fixed partitioning scheme
Non-partitioned media
TestDisk can perform deeper checks to locate partitions that have been deleted from the partition table. However, it is up to the user to look over the list of possible partitions found by TestDisk and to select those that they wish to recover.
After partitions are located, TestDisk can rebuild the partition table and rewrite the MBR.
Filesystem repair
TestDisk can deal with some specific logical filesystem corruption.
File recovery
When a file is
|
https://en.wikipedia.org/wiki/SerDes
|
A Serializer/Deserializer (SerDes) is a pair of functional blocks commonly used in high speed communications to compensate for limited input/output. These blocks convert data between serial data and parallel interfaces in each direction. The term "SerDes" generically refers to interfaces used in various technologies and applications. The primary use of a SerDes is to provide data transmission over a single line or a differential pair in order to minimize the number of I/O pins and interconnects.
Generic function
The basic SerDes function is made up of two functional blocks: the Parallel In Serial Out (PISO) block (aka Parallel-to-Serial converter) and the Serial In Parallel Out (SIPO) block (aka Serial-to-Parallel converter). There are 4 different SerDes architectures: (1) Parallel clock SerDes, (2) Embedded clock SerDes, (3) 8b/10b SerDes, (4) Bit interleaved SerDes.
The PISO (Parallel Input, Serial Output) block typically has a parallel clock input, a set of data input lines, and input data latches. It may use an internal or external phase-locked loop (PLL) to multiply the incoming parallel clock up to the serial frequency. The simplest form of the PISO has a single shift register that receives the parallel data once per parallel clock, and shifts it out at the higher serial clock rate. Implementations may also make use of a double-buffered register to avoid metastability when transferring data between clock domains.
The SIPO (Serial Input, Parallel Output) block typically has a receive clock output, a set of data output lines and output data latches. The receive clock may have been recovered from the data by the serial clock recovery technique. However, SerDes which do not transmit a clock use reference clock to lock the PLL to the correct Tx frequency, avoiding low harmonic frequencies present in the data stream. The SIPO block then divides the incoming clock down to the parallel rate. Implementations typically have two registers connected as a double buff
|
https://en.wikipedia.org/wiki/MIT%20Plasma%20Science%20and%20Fusion%20Center
|
The Plasma Science and Fusion Center (PSFC) at the Massachusetts Institute of Technology (MIT) is a university research center for the study of plasmas, fusion science and technology.
It was originally founded in 1976 as the Plasma Fusion Center (PFC) at the request and with the collaboration of the U.S. Department of Energy. The original grant was for construction and operation of a tokamak reactor Alcator A, the first in a series of small, high-field tokamaks, followed by Alcator C (1978) and Alcator C-Mod (1993).
MIT's most recent tokamak, Alcator C-Mod, ran from 1993 to 2016. In 2016, the project pressure reached 2.05 atmospheres—a 15 percent jump over the previous record of 1.77 atmospheres with a plasma temperature of 35 million degrees C, sustaining fusion for 2 seconds, yielding 600 trillion fusion reactions. The run involved a 5.7 tesla magnetic field. It reached this milestone on its final day of operation.
In 2018, the PSFC began developing a conceptual design for the SPARC tokamak in collaboration with Commonwealth Fusion Systems. SPARC intends to use new YBCO superconducting magnets in order to achieve net fusion energy in a compact device.
|
https://en.wikipedia.org/wiki/NOD%20mice
|
Non-obese diabetic or NOD mice, like biobreeding rats, are used as an animal model for type 1 diabetes. Diabetes develops in NOD mice as a result of insulitis, a leukocytic infiltrate of the pancreatic islets. The onset of diabetes is associated with a moderate glycosuria and a non-fasting hyperglycemia. It is recommended to monitor for development of glycosuria from 10 weeks of age; this can be carried out using urine glucose dipsticks. NOD mice will develop spontaneous diabetes when left in a sterile environment. The incidence of spontaneous diabetes in the NOD mouse is 60–80% in females and 20–30% in males. Onset of diabetes also varies between males and females: commonly, onset is delayed in males by several weeks. The mice (as well as C57BL/6 and SJL) are known to carry IgG2c allele.
History
Non-obese diabetic (NOD) mice exhibit a susceptibility to spontaneous development of autoimmune insulin dependent diabetes mellitus (IDDM). The NOD strain and related strains were developed at Shionogi Research Laboratories in Aburahi, Japan by Makino and colleagues and first reported in 1980. The group developed the NOD strain by an outbreeding of the cataract-prone strain from JcI:ICR mice.
Susceptibility
The susceptibility to IDDM is polygenic and environment exerts a strong effect on gene penetrances. Environment including housing conditions, health status, and diet all affect development of diabetes in the mice. For instance, NOD mice maintained in different laboratories can have different levels of incidence. The incidence of disease is linked to the microbiome.
NOD mice are also susceptible to developing other autoimmune syndromes, including autoimmunine sialitis, autoimmune thyroiditis, autoimmune peripheral polyneuropathy etc. Diabetes in these mice can be prevented by a single injection of mycobacterial adjuvants such as complete Freund's adjuvant (FCA) or Bacille de Calmette et Guérin (BCG) vaccine.
Identifying IDDM susceptibility loci
Genetic Loci assoc
|
https://en.wikipedia.org/wiki/Palaeosaurus
|
Palaeosaurus (or Paleosaurus) is a genus of indeterminate archosaur known from two teeth found in the Bromsgrove Sandstone Formation and also either the Magnesian Conglomerate or the Avon Fissure Fill of Clifton, Bristol, England (originally Avon). It has had a convoluted taxonomic history.
Richard Owen's mistake of associating prosauropod skeletal remains with the carnivorous teeth which Riley and Stutchbury called Palaeosaurus, combined with Friedrich von Huene's Teratosaurus minor, which was also a combination of carnivore and prosauropod remains, led paleontologists to view prosauropods as carnivorous animals for quite a long time. This error made it into several textbooks and other dinosaur reference works.
History and classification
Nineteenth century
In the autumn of 1834, surgeon Henry Riley (1797–1848) and the curator of the Bristol Institution, Samuel Stutchbury (15 January 1798 – 12 February 1859), began to excavate "saurian remains" at the quarry of Durdham Down, at Clifton, presently a part of Bristol, which is part of the Magnesian Conglomerate. In 1834 and 1835, they briefly reported on the finds. They provided their initial description in 1836, naming two new genera: Palaeosaurus and Thecodontosaurus. In 1836 Riley and Stutchbury briefly and informally published on two new fossil teeth (the holotype tooth of P. platyodon is listed under BRSMG *Ca7448/3 and the holotype tooth of P. cylindrodon is listed under BRSMG *Ca7449/4. Both are now listed under the latter species) found in or near the city of Bristol, England, which they called Palaeosaurus cylindrodon and Palaeosaurus platyodon. Riley and Stutchbury did not mean to assign these species to Saint-Hilaire's genus of teleosaurids; they simply did not know the name had been used. Thecodontosaurus was also named in this publication. Only in 1840 do Riley and Stutchbury fully describe their two species of Palaeosaurus, each based on a single sharp tooth from the Late Triassic Period. The spelling
|
https://en.wikipedia.org/wiki/Encyclopedia%20of%20Earth
|
The Encyclopedia of Earth (abbreviated EoE) is an electronic reference about the Earth, its natural environments, and their interaction with society. The Encyclopedia is described as a free, fully searchable collection of articles written by scholars, professionals, educators, and other approved experts, who collaborate and review each other's work. The articles are written in non-technical language and are intended to be useful to students, educators, scholars, and professionals, as well as to the general public. The authors, editors, and even copy editors are attributed on the articles with links to biographical pages on those individuals.
The Encyclopedia of Earth is a component of the larger Earth Portal (part of the Digital Universe project), which is a constellation of subject-specific information portals that contain news services, structured metadata, a federated environmental search engine, and other information resources. The technology platform for the Encyclopedia of Earth is a modified version of MediaWiki, which is closed to all but approved users. Once an article is reviewed and approved it is published to a public site. The EoE was launched in September 2006 with about 360 articles, and as of November 30, 2010 had 7,678 articles.
Authoring and publishing process
Contributors to the Encyclopedia of Earth are made up of scientists, educators, and professionals within the environmental field. Contributors are vetted by the Environmental Information Coalition (EIC) Stewardship Committee, the governing body of the Encyclopedia of Earth, before they are given access to the author's wiki. Within the wiki, where they operate under their real names and are given attribution for the published articles.
Articles are written, edited, and published in a two-step process:
Content for the Encyclopedia is created, maintained, and governed by group of experts via a restricted-access wiki that uses a modified version of MediaWiki.
Upon completion, content is rev
|
https://en.wikipedia.org/wiki/.NET%20Remoting
|
.NET Remoting is a Microsoft application programming interface (API) for interprocess communication released in 2002 with the 1.0 version of .NET Framework. It is one in a series of Microsoft technologies that began in 1990 with the first version of Object Linking and Embedding (OLE) for 16-bit Windows. Intermediate steps in the development of these technologies were Component Object Model (COM) released in 1993 and updated in 1995 as COM-95, Distributed Component Object Model (DCOM), released in 1997 (and renamed ActiveX), and COM+ with its Microsoft Transaction Server (MTS), released in 2000. It is now superseded by Windows Communication Foundation (WCF), which is part of the .NET Framework 3.0.
Like its family members and similar technologies such as Common Object Request Broker Architecture (CORBA) and Java's remote method invocation (RMI), .NET Remoting is complex, yet its essence is straightforward. With the assistance of operating system and network agents, a client process sends a message to a server process and receives a reply.
Overview
.NET Remoting allows an application to make an object (termed remotable object) available across remoting boundaries, which includes different appdomains, processes or even different computers connected by a network. The .NET Remoting runtime hosts the listener for requests to the object in the appdomain of the server application. On the client end, any requests to the remotable object are proxied by the .NET Remoting runtime over Channel objects, that encapsulate the actual transport mode, including TCP streams, HTTP streams and named pipes. As a result, by instantiating proper Channel objects, a .NET Remoting application can be made to support different communication protocols without recompiling the application. The runtime itself manages the act of serialization and marshalling of objects across the client and server appdomains.
.NET Remoting makes a reference of a remotable object available to a client application,
|
https://en.wikipedia.org/wiki/Intertubercular%20plane
|
A lower transverse plane midway between the upper transverse and the upper border of the pubic symphysis; this is termed the intertubercular plane (or transtubercular), since it practically corresponds to that passing through the iliac tubercles; behind, its plane cuts the body of the fifth lumbar vertebra.
Additional images
See also
Transpyloric plane
|
https://en.wikipedia.org/wiki/Transpyloric%20plane
|
The transpyloric plane, also known as Addison's plane, is an imaginary horizontal plane, located halfway between the suprasternal notch of the manubrium and the upper border of the symphysis pubis at the level of the first lumbar vertebrae, L1. It lies roughly a hand's breadth beneath the xiphisternum or midway between the xiphisternum and the umbilicus. The plane in most cases cuts through the pylorus of the stomach, the tips of the ninth costal cartilages and the lower border of the first lumbar vertebra.
Structures crossed
The transpyloric plane is clinically notable because it passes through several important abdominal structures. It also divides the supracolic and infracolic compartments, with the liver, spleen and gastric fundus above it and the small intestine and colon below it.
Lumbar vertebra and spinal cord
The first lumbar vertebra lies at the level of the transpyloric plane. Despite the conus medullaris, the end of the spinal cord, being understood to terminate at the level of the transpyloric plane, there is significant variability. Up to 40% of people have spinal cords ending below the transpyloric plane.
Stomach
The transpyloric plane passes through the pylorus of the stomach, despite it being suspended by the lesser and greater omentum and being relatively mobile.
Duodenum
The horizontal part of the duodenum slopes upwards to the left of the vertical midline, following which the vertical ascending part of the duodenum reaches the transpyloric plane. It ends in the duodenojejunal junction, which lies approximately 2.5 cm to the left of the midline and just below the transpyloric plane.
Pancreas
The neck of pancreas lies on the transpyloric plane, whilst the body and tail are to the left and above it.
Gallbladder
The fundus of the gallbladder projects from the liver's inferior border at the intersection of the transpyloric plane and the right lateral midline.
Kidneys
Despite the right kidney lying 1 cm lower than the left (right just below and
|
https://en.wikipedia.org/wiki/Henri%20Poincar%C3%A9%20Prize
|
The Henri Poincaré Prize is awarded every three years since 1997 for exceptional achievements in mathematical physics and foundational contributions
leading to new developments in the field. The prize is sponsored by the Daniel Iagolnitzer Foundation and is awarded to approximately three scientists at the International Congress on Mathematical Physics. The prize was also established to support promising young researchers that already made outstanding contributions in mathematical physics.
Prize recipients
See also
Henri Poincaré
List of physics awards
List of mathematics awards
|
https://en.wikipedia.org/wiki/Coracoclavicular%20ligament
|
The coracoclavicular ligament is a ligament of the shoulder. It connects the clavicle to the coracoid process of the scapula.
Structure
The coracoclavicular ligament connects the clavicle to the coracoid process of the scapula. It is not part of the acromioclavicular joint articulation, but is usually described with it, since it keeps the clavicle in contact with the acromion. It consists of two fasciculi, the trapezoid ligament in front, and the conoid ligament behind. These ligaments are in relation, in front, with the subclavius muscle and the deltoid muscle; behind, with the trapezius.
Variation
The insertions of the coracoclavicular ligament can occur in slightly different places in different people. It may contain three fascicles rather than two.
Function
The coracoclavicular ligament is a strong stabilizer of the acromioclavicular joint. It is also important in the transmission of weight of the upper limb to the axial skeleton. There is very little movement at the AC joint.
Clinical significance
The coracoclavicular ligament may be damaged during a severe dislocated clavicle. Damage may be repaired with surgery.
|
https://en.wikipedia.org/wiki/Sternoclavicular%20joint
|
The sternoclavicular joint or sternoclavicular articulation is a synovial saddle joint between the manubrium of the sternum, and the clavicle, and the first costal cartilage. The joint possesses a joint capsule, and an articular disc, and is reinforced by multiple ligaments.
Structure
The joint is structurally classified as a synovial saddle joint and functionally classed as a diarthrosis and multiaxial joint. It is composed of two portions separated by an articular disc of fibrocartilage.
The joint is formed by the sternal end of the clavicle, the clavicular notch of the sternum, and (the superior surface of) the costal cartilage of the first rib. The articular surface of the clavicle is larger than that of the sternum, and is invested with a layer of cartilage, which is considerably thicker than that of the sternum.
The joint receives arterial supply via branches of the internal thoracic artery and the suprascapular artery. It is innervated via the medial supraclavicular nerve (superficially), and the nerve to subclavius (deeply).
Joint capsule
The joint capsule is thickened anteriorly and posteriorly, but is thinner superiorly and (especially) inferiorly, where it consists mostly of loose areolar connective tissue.
Articular disc
The joint features a fibrocartilaginous articular disc which completely divides the joint to form two articular compartments. the disc acts to increase the range of movement of the joint.
Ligaments
The joint is reinforced by two intrinsic and two extrinsic ligaments. The costoclavicular ligament is the main limitation to movement, and therefore the main stabilizer of the joint.
Anterior sternoclavicular ligament (intrinsic)
Posterior sternoclavicular ligament (intrinsic)
Costoclavicular ligament (extrinsic)
Interclavicular ligament (extrinsic)
Function
The sternoclavicular joint allows movement of the clavicle in three planes, predominantly in the anteroposterior and vertical planes, although some rotation also occurs. A d
|
https://en.wikipedia.org/wiki/History%20of%20machine%20translation
|
Machine translation is a sub-field of computational linguistics that investigates the use of software to translate text or speech from one natural language to another.
In the 1950s, machine translation became a reality in research, although references to the subject can be found as early as the 17th century. The Georgetown experiment, which involved successful fully automatic translation of more than sixty Russian sentences into English in 1954, was one of the earliest recorded projects. Researchers of the Georgetown experiment asserted their belief that machine translation would be a solved problem within three to five years. In the Soviet Union, similar experiments were performed shortly after.
Consequently, the success of the experiment ushered in an era of significant funding for machine translation research in the United States. The achieved progress was much slower than expected; in 1966, the ALPAC report found that ten years of research had not fulfilled the expectations of the Georgetown experiment and resulted in dramatically reduced funding.
Interest grew in statistical models for machine translation, which became more common and also less expensive in the 1980s as available computational power increased.
Although there exists no autonomous system of "fully automatic high quality translation of unrestricted text," there are many programs now available that are capable of providing useful output within strict constraints. Several of these programs are available online, such as Google Translate and the SYSTRAN system that powers AltaVista's BabelFish (which was replaced by Microsoft Bing translator in May 2012).
The beginning
The origins of machine translation can be traced back to the work of Al-Kindi, a 9th-century Arabic cryptographer who developed techniques for systemic language translation, including cryptanalysis, frequency analysis, and probability and statistics, which are used in modern machine translation. The idea of machine translation late
|
https://en.wikipedia.org/wiki/Poincar%C3%A9%20Seminars
|
The Poincaré Seminars, named for the mathematician and theoretical physicist Henri Poincaré, were founded in 2001. They are nicknamed Bourbaphy for their inspiration by the Bourbaki Seminars.
The goal of this seminar is to provide information on topics of current interest in physics. Its way of working is directly inspired by the Bourbaki Seminar in mathematics. A series of pedagogical talks aims at explaining a topic of current interest both from a theoretical and an experimental point of view, possibly complemented by a historical introduction. A booklet with the contributions of the speakers is distributed on the day of the seminar. The seminar aims at a general audience of mathematicians and physicists and does not require any specialized knowledge.
Publications
External links
English pages about Bourbaphy at the Centre National de la Recherche Scientifique
Physics conferences
|
https://en.wikipedia.org/wiki/Annales%20Henri%20Poincar%C3%A9
|
The Annales Henri Poincaré (A Journal of Theoretical and Mathematical Physics) is a peer-reviewed scientific journal which collects and publishes original research papers in the field of theoretical and mathematical physics. The emphasis is on "analytical theoretical and mathematical physics" in a broad sense. The journal is named in honor of Henri Poincaré and it succeeds two former journals, Annales de l'Institut Henri Poincaré, physique théorique and Helvetica Physical Acta (). It is published by Birkhäuser Verlag. Its first Chief Editor was Vincent Rivasseau, followed by Krzysztof Gawedzki, and the current Chief Editor is Claude-Alain Pillet.
Abstracting and indexing
According to the Journal Citation Reports, the journal had a 2020 impact factor of 1.550. The journal is published as one volume of 12 issues per year and is abstracted or indexed in the following databases: Academic OneFile, Academic Search, Current Abstracts, Current Contents/Physical, Chemical and Earth Sciences, Digital Mathematics Registry, Gale, Google Scholar, Inspec, Journal Citation Reports/Science Edition, Mathematical Reviews, OCLC, Science Citation Index, Science Citation Index Expanded (SciSearch), SCOPUS, Summon by Serial Solutions, TOC Premier, VINITI - Russian Academy of Science, Zentralblatt Math
See also
Institut Henri Poincaré
|
https://en.wikipedia.org/wiki/Rectal%20venous%20plexus
|
The rectal venous plexus (or hemorrhoidal plexus) is the venous plexus surrounding the rectum. It consists of an internal and an external rectal plexus. It is drained by the superior, middle, and inferior rectal veins. It forms a portosystemic (portocaval) anastomosis. This allows rectally administered medications to bypassing first pass metabolism.
Despite the inclusion of the term "rectal" into the name, the venous plexus is positionally, functionally, and clinically primarily related to the anal canal.
Anatomy
The rectal venous plexus consists of an external rectal plexus that is situated outside to the muscular wall, and an internal rectal plexus that is situated in the submucosa/deep to the mucosa of the rectum and proximal anal canal at the anorectal junction.
Internal rectal plexus
The internal plexus presents a series of dilated pouches which are arranged in a circle around the tube, immediately above the anal orifice, and are connected by transverse branches.
The internal plexus (sources differ) forms/is continuous distally/inferiorly with the hemorrhoids (the vascular cushions of the anal canal).
Venous drainage
According to the 42nd edition of Gray's Anatomy (2020), the internal rectal plexus is drained mostly by the superior rectal vein (→inferior mesenteric vein→splenic vein→hepatic portal vein).
According to the 8th edition of Clinically Oriented Anatomy (2017), the internal rectal plexus is drains mostly into the superior rectal vein superior/proximal to the pectinate line, and into the inferior rectal veins (→internal pudendal vein→internal iliac vein→common iliac vein→inferior vena cava) around the margin of the external anal sphincter inferior/distal to the pectinate line.
External rectal plexus
Venous drainage
The proximal/superior part mostly drains into the superior rectal vein (→inferior mesenteric vein→splenic vein→hepatic portal vein)
The middle part drains into middle rectal vein(s) (→internal iliac vein→common iliac vein→inferio
|
https://en.wikipedia.org/wiki/Frederic%20Bennett
|
Sir Frederic Mackarness Bennett (2 December 1918 – 14 September 2002) was a British journalist, author, barrister and Conservative politician who served as a Member of Parliament for 35 years. He was appointed a Privy Counsellor in 1985, and a Deputy Lieutenant for Greater London in 1990. He was also Lord of the manor of Mawddwy in Wales.
Early years
The second son of Sir Ernest Nathaniel Bennett, (died 1947) of Cwmllecoediog, Aberangell, Wales, by his wife Marguerite (née Kleinwort), Bennett was educated at Westminster School, and Lincoln's Inn, and was called to the English Bar in November 1946. He subsequently served as an Advocate in the High Court of Southern Rhodesia from March 1947, and in 1947 he made the first overland car journey from South Africa to England.
From 1947 to 1949 he was an Official Observer in the Greek Civil War, becoming diplomatic correspondent for the Birmingham Post from 1950 to 1952. Later a director in various financial and industrial institutions in the United Kingdom and overseas, he was also an underwriter at Lloyd's.
Military
In 1939 Bennett enlisted in the Middlesex Yeomanry. He was commissioned as an officer into the Royal Artillery in 1940; commended for gallantry in 1941; was Military Experimental Officer in the Petroleum Warfare Department, 1943–1946, then released to reserve with the permanent rank of Major.
Political career
At the 1945 general election, Bennett was an unsuccessful candidate in the Burslem constituency, in Staffordshire. At the 1950 general election, he stood in the Birmingham Ladywood constituency, again unsuccessfully.
The following year, at the 1951 general election, he was finally elected to the House of Commons as Member of Parliament (MP) for Reading North. When that constituency was abolished for the general election in May 1955, Bennett stood for in election in the new Reading seat, but lost by 238 votes to Labour's Ian Mikardo, the outgoing MP for the abolished Reading South constituency.
|
https://en.wikipedia.org/wiki/Jawed%20Siddiqi
|
Jawed Siddiqi FBCS is a Pakistani British computer scientist and software engineer. He is professor emeritus of software engineering at Sheffield Hallam University, England. He is the president of NCUP National Council of University Professors in the UK.
Education and academic career
Siddiqi received a BSc degree in mathematics from the University of London, followed by an MSc and PhD in computer science at the University of Aston, Birmingham. During 1991–1993, he was a visiting researcher at the Centre for Requirements and Foundation at the Oxford University Computing Laboratory (now the Oxford University Department of Computer Science), working with Professor Joseph Goguen in the area of requirements engineering. Siddiqi has been involved with the BCS Formal Aspects of Computing Science (FACS) Specialist Group for many years. Currently he is chair of the group. Siddiqi is also an executive member of the IEEE Technical Council on Software Engineering (TCSE). Siddiqi is a British computer scientist, fellow of the British Computer Society, a member of the IEEE, and a member of the ACM. He is a co-editor of Formal Methods: State of the Art and New Directions.
Fighting racism
Siddiqi has for three decades has been involved in countering racism and fighting for social justice. He was a founding member and chair of the North Staffordshire Racial Equality Council, executive member of the West Midlands Regional Board for Commission for Racial Equality, secretary of the Black Justice Project and chair of Sheffield Racial Harassment Project. He has written about and been invited to speak on countering racism particularly structural racism. He is the vice chair of The Monitoring Group (TMG). TMG works with all sections of the black and Asian communities to that are facing hostility, abuse and violence from racists. It has been involved in several high-profile cases: the Stephen Lawrence family, Sarfraz Najeib family and Zahid Mubarek family.
Public service
Siddiqi was
|
https://en.wikipedia.org/wiki/Flash%20ADC
|
A flash ADC (also known as a direct-conversion ADC) is a type of analog-to-digital converter that uses a linear voltage ladder with a comparator at each "rung" of the ladder to compare the input voltage to successive reference voltages. Often these reference ladders are constructed of many resistors; however, modern implementations show that capacitive voltage division is also possible. The output of these comparators is generally fed into a digital encoder, which converts the inputs into a binary value (the collected outputs from the comparators can be thought of as a unary value).
Benefits and drawbacks
Flash converters are high-speed compared to many other ADCs, which usually narrow in on the "correct" answer over a series of stages. However, compared to these, a flash converter is also quite simple and, apart from the analog comparators, only requires logic for the final conversion to binary.
For best accuracy, a track-and-hold circuit is often inserted in front of the ADC input. This is needed for many ADC types (like successive approximation ADC), but for flash ADCs, there is no real need for this because the comparators are the sampling devices.
A flash converter requires many comparators compared to other ADCs, especially as the precision increases. For example, a flash converter requires comparators for an n-bit conversion. The size, power consumption, and cost of all those comparators make flash converters generally impractical for precisions much greater than 8 bits (255 comparators). In place of these comparators, most other ADCs substitute more complex logic and/or analog circuitry that can be scaled more easily for increased precision.
Implementation
Flash ADCs have been implemented in many technologies, varying from silicon-based bipolar (BJT) and complementary metal–oxide FETs (CMOS) technologies to rarely used III-V technologies. This type of ADC is often used as a first medium-sized analog circuit verification.
The earliest implementations c
|
https://en.wikipedia.org/wiki/Voltage%20ladder
|
A voltage ladder is a simple electronic circuit consisting of several resistors connected in series with a voltage placed across the entire resistor network, a generalisation of a two-resistor voltage divider. Connections to the nodes provide access to the voltages available. Voltage ladders are useful for providing a set of successive voltage references, for instance for a flash analog-to-digital converter.
Operation
A voltage drop occurs across each resistor in the network causing each successive "rung" of the ladder (each node of the circuit) to have a higher voltage than the previous one.
Since the ladder is a series circuit, the current is the same throughout, and is given by the total voltage divided by the total series resistance (V/Req). The voltage drop across any one resistor is I×Rn, where I is the current calculated above, and Rn is the resistance of the resistor in question. The voltage referenced to ground at any node is simply the sum of the voltages dropped by each resistor between that node and ground.
Alternatively node voltages can be calculated using voltage division: the voltage drop across any resistor is V×Rn/Req where V is the total voltage, Req is the total (equivalent) resistance, and Rn is the resistance of the resistor in question. The voltage of a node referenced to ground is the sum of the drops across all the resistors, but it's now easier to consider all these resistors as a single equivalent resistance RT, which is simply the sum of all the resistances between the node and ground, so the node voltage is given by V×RT/Req.
|
https://en.wikipedia.org/wiki/MSN%20Chat
|
MSN Chat was the Microsoft Network version of IRCX (Internet Relay Chat extensions by Microsoft), which replaced Microsoft Chat, a set of Exchange-based IRCX servers first available in the Microsoft Comic Chat client, although Comic Chat was not required to connect.
History
Client Compatibility
According to the MSN Chat website, the following were required to use the MSN Chat Service:
Windows 95 or later
Internet Explorer 4.0 or later OR;
Netscape Navigator 4.x
The Microsoft Network Chat Control was developed as an ActiveX Component Object Model (COM) Object. ActiveX, being a Microsoft technology provided limited compatibility for other products. The other major platforms beside Internet Explorer that MSN Chat was supported on, was Netscape Navigator and MSNTV (formerly known as WebTV). To ensure the MSN Chat network was only being connected to by authorized clients, Microsoft created and implemented a SASL based Security Service Provider authentication package known as GateKeeper. This used a randomized session key to authorize users not using the Microsoft Passport (now Microsoft account) system. Microsoft used another SSP known as GateKeeperPassport, that worked from the same method but required certain attributes related to the user's account.
Defeating the "Authentication Challenge"
There have been various methods through the use of mIRC to access the MSN Chat Network. Most of the methods were through the use of the MSN Chat Control itself, yet others were more complicated.
In the beginning, shortly after the move from Microsoft Chat, the MSN Chat Network could be directly connected to through any IRC Client to irc.msn.com on port 6667. Perhaps because of abuse or other factors, such as the desire to authenticate users based on their Microsoft Passport, Microsoft implemented GateKeeper and GateKeeperPassport, and integrated both into their chat control. The weakness of GateKeeper and the fact the early MSN Chat Controls (1.0−3.0) had public functions
|
https://en.wikipedia.org/wiki/Causal%20consistency
|
Causal consistency is one of the major memory consistency models. In concurrent programming, where concurrent processes are accessing a shared memory, a consistency model restricts which accesses are legal. This is useful for defining correct data structures in distributed shared memory or distributed transactions.
Causal Consistency is “Available under Partition”, meaning that a process can read and write the memory (memory is Available) even while there is no functioning network connection (network is Partitioned) between processes; it is an asynchronous model. Contrast to strong consistency models, such as sequential consistency or linearizability, which cannot be both safe and live under partition, and are slow to respond because they require synchronisation.
Causal consistency was proposed in 1990s as a weaker consistency model for shared memory models. Causal consistency is closely related to the concept of Causal Broadcast in communication protocols. In these models, a distributed execution is represented as a partial order, based on Lamport's happened-before concept of potential causality.
Causal consistency is a useful consistency model because it matches programmers' intuitions about time, is more available than strong consistency models, yet provides more useful guarantees than eventual consistency. For instance, in distributed databases, causal consistency supports the ordering of operations, in contrast to eventual consistency. Also, causal consistency helps with the development of abstract data types such as queues or counters.
Since time and ordering are so fundamental to our intuition, it is hard
to reason about a system that does not enforce causal consistency.
However, many distributed databases lack this guarantee, even ones that
provide serialisability.
Spanner does guarantee causal consistency, but it also forces strong consistency, thus eschewing availability under partition.
More available databases that ensure causal consistenc
|
https://en.wikipedia.org/wiki/Log%20analysis
|
In computer log management and intelligence, log analysis (or system and network log analysis) is an art and science seeking to make sense of computer-generated records (also called log or audit trail records). The process of creating such records is called data logging.
Typical reasons why people perform log analysis are:
Compliance with security policies
Compliance with audit or regulation
System troubleshooting
Forensics (during investigations or in response to a subpoena)
Security incident response
Understanding online user behavior
Logs are emitted by network devices, operating systems, applications and all manner of intelligent or programmable devices. A stream of messages in time sequence often comprises a log. Logs may be directed to files and stored on disk or directed as a network stream to a log collector.
Log messages must usually be interpreted concerning the internal state of its source (e.g., application) and announce security-relevant or operations-relevant events (e.g., a user login, or a systems error).
Logs are often created by software developers to aid in the debugging of the operation of an application or understanding how users are interacting with a system, such as a search engine. The syntax and semantics of data within log messages are usually application or vendor-specific. The terminology may also vary; for example, the authentication of a user to an application may be described as a log in, a logon, a user connection or an authentication event. Hence, log analysis must interpret messages within the context of an application, vendor, system or configuration to make useful comparisons to messages from different log sources.
Log message format or content may not always be fully documented. A task of the log analyst is to induce the system to emit the full range of messages to understand the complete domain from which the messages must be interpreted.
A log analyst may map varying terminology from different log sources into a uni
|
https://en.wikipedia.org/wiki/Jacobi%20eigenvalue%20algorithm
|
In numerical linear algebra, the Jacobi eigenvalue algorithm is an iterative method for the calculation of the eigenvalues and eigenvectors of a real symmetric matrix (a process known as diagonalization). It is named after Carl Gustav Jacob Jacobi, who first proposed the method in 1846, but only became widely used in the 1950s with the advent of computers.
Description
Let be a symmetric matrix, and be a Givens rotation matrix. Then:
is symmetric and similar to .
Furthermore, has entries:
where and .
Since is orthogonal, and have the same Frobenius norm (the square-root sum of squares of all components), however we can choose such that , in which case has a larger sum of squares on the diagonal:
Set this equal to 0, and rearrange:
if
In order to optimize this effect, Sij should be the off-diagonal element with the largest absolute value, called the pivot.
The Jacobi eigenvalue method repeatedly performs rotations until the matrix becomes almost diagonal. Then the elements in the diagonal are approximations of the (real) eigenvalues of S.
Convergence
If is a pivot element, then by definition for . Let denote the sum of squares of all off-diagonal entries of . Since has exactly off-diagonal elements, we have or . Now . This implies
or ;
that is, the sequence of Jacobi rotations converges at least linearly by a factor to a diagonal matrix.
A number of Jacobi rotations is called a sweep; let denote the result. The previous estimate yields
;
that is, the sequence of sweeps converges at least linearly with a factor ≈ .
However the following result of Schönhage yields locally quadratic convergence. To this end let S have m distinct eigenvalues with multiplicities and let d > 0 be the smallest distance of two different eigenvalues. Let us call a number of
Jacobi rotations a Schönhage-sweep. If denotes the result then
.
Thus convergence becomes quadratic as soon as
Cost
Each Jacobi rotation can be do
|
https://en.wikipedia.org/wiki/Quantum%20point%20contact
|
A quantum point contact (QPC) is a narrow constriction between two wide electrically conducting regions, of a width comparable to the electronic wavelength (nano- to micrometer).
The importance of QPC lies in the fact that they prove quantisation of ballistic conductance in mesoscopic systems. The conductance of a QPC is quantized in units of , the so-called conductance quantum.
Quantum point contacts were first reported in 1988 by a Dutch team from Delft University of Technology and Philips Research and, independently, by a British team from the Cavendish Laboratory. They are based on earlier work by the British group which showed how split gates could be used to convert a two-dimensional electron gas into one-dimension, first in silicon and then in gallium arsenide.
This quantisation is reminiscent of the quantisation of the Hall conductance, but is measured in the absence of a magnetic field. The zero-field conductance quantisation and the smooth transition to the quantum Hall effect on applying a magnetic field are essentially consequences of the equipartition of current among an integer number of propagating modes in the constriction.
Fabrication
There are several different ways of fabricating a quantum point contact. It can be realized in a break-junction by pulling apart a piece of conductor until it breaks. The breaking point forms the point contact. In a more controlled way, quantum point contacts are formed in a two-dimensional electron gas (2DEG), e.g. in GaAs/AlGaAs heterostructures. By applying a voltage to suitably shaped gate electrodes, the electron gas can be locally depleted and many different types of conducting regions can be created in the plane of the 2DEG, among them quantum dots and quantum point contacts. Another means of creating a QPC is by positioning the tip of a scanning tunneling microscope close to the surface of a conductor.
Properties
Geometrically, a quantum point contact is a constriction in the transverse direction which pr
|
https://en.wikipedia.org/wiki/Quasi-bialgebra
|
In mathematics, quasi-bialgebras are a generalization of bialgebras: they were first defined by the Ukrainian mathematician Vladimir Drinfeld in 1990. A quasi-bialgebra differs from a bialgebra by having coassociativity replaced by an invertible element which controls the non-coassociativity. One of their key properties is that the corresponding category of modules forms a tensor category.
Definition
A quasi-bialgebra is an algebra over a field equipped with morphisms of algebras
along with invertible elements , and such that the following identities hold:
Where and are called the comultiplication and counit, and are called the right and left unit constraints (resp.), and is sometimes called the Drinfeld associator. This definition is constructed so that the category is a tensor category under the usual vector space tensor product, and in fact this can be taken as the definition instead of the list of above identities. Since many of the quasi-bialgebras that appear "in nature" have trivial unit constraints, ie. the definition may sometimes be given with this assumed. Note that a bialgebra is just a quasi-bialgebra with trivial unit and associativity constraints: and .
Braided quasi-bialgebras
A braided quasi-bialgebra (also called a quasi-triangular quasi-bialgebra) is a quasi-bialgebra whose corresponding tensor category is braided. Equivalently, by analogy with braided bialgebras, we can construct a notion of a universal R-matrix which controls the non-cocommutativity of a quasi-bialgebra. The definition is the same as in the braided bialgebra case except for additional complications in the formulas caused by adding in the associator.
Proposition: A quasi-bialgebra is braided if it has a universal R-matrix, ie an invertible element such that the following 3 identities hold:
Where, for every , is the monomial with in the th spot, where any omitted numbers correspond to the identity in that spot. Finally we extend this by linearity to all o
|
https://en.wikipedia.org/wiki/Quasi-Hopf%20algebra
|
A quasi-Hopf algebra is a generalization of a Hopf algebra, which was defined by the Russian mathematician Vladimir Drinfeld in 1989.
A quasi-Hopf algebra is a quasi-bialgebra for which there exist and a bijective antihomomorphism S (antipode) of such that
for all and where
and
where the expansions for the quantities and are given by
and
As for a quasi-bialgebra, the property of being quasi-Hopf is preserved under twisting.
Usage
Quasi-Hopf algebras form the basis of the study of Drinfeld twists and the representations in terms of F-matrices associated with finite-dimensional irreducible representations of quantum affine algebra. F-matrices can be used to factorize the corresponding R-matrix. This leads to applications in Statistical mechanics, as quantum affine algebras, and their representations give rise to solutions of the Yang–Baxter equation, a solvability condition for various statistical models, allowing characteristics of the model to be deduced from its corresponding quantum affine algebra. The study of F-matrices has been applied to models such as the Heisenberg XXZ model in the framework of the algebraic Bethe ansatz. It provides a framework for solving two-dimensional integrable models by using the quantum inverse scattering method.
See also
Quasitriangular Hopf algebra
Quasi-triangular quasi-Hopf algebra
Ribbon Hopf algebra
|
https://en.wikipedia.org/wiki/Quantum%20Heisenberg%20model
|
The quantum Heisenberg model, developed by Werner Heisenberg, is a statistical mechanical model used in the study of critical points and phase transitions of magnetic systems, in which the spins of the magnetic systems are treated quantum mechanically. It is related to the prototypical Ising model, where at each site of a lattice, a spin represents a microscopic magnetic dipole to which the magnetic moment is either up or down. Except the coupling between magnetic dipole moments, there is also a multipolar version of Heisenberg model called the multipolar exchange interaction.
Overview
For quantum mechanical reasons (see exchange interaction or ), the dominant coupling between two dipoles may cause nearest-neighbors to have lowest energy when they are aligned. Under this assumption (so that magnetic interactions only occur between adjacent dipoles) and on a 1-dimensional periodic lattice, the Hamiltonian can be written in the form
,
where is the coupling constant and dipoles are represented by classical vectors (or "spins") σj, subject to the periodic boundary condition .
The Heisenberg model is a more realistic model in that it treats the spins quantum-mechanically, by replacing the spin by a quantum operator acting upon the tensor product , of dimension . To define it, recall the Pauli spin-1/2 matrices
,
,
,
and for and denote , where is the identity matrix.
Given a choice of real-valued coupling constants and , the Hamiltonian is given by
where the on the right-hand side indicates the external magnetic field, with periodic boundary conditions. The objective is to determine the spectrum of the Hamiltonian, from which the partition function can be calculated and the thermodynamics of the system can be studied.
It is common to name the model depending on the values of , and : if , the model is called the Heisenberg XYZ model; in the case of , it is the Heisenberg XXZ model; if , it is the Heisenberg XXX model. The spin 1/2 Heisenberg model in
|
https://en.wikipedia.org/wiki/CARD%20%28domain%29
|
Caspase recruitment domains, or caspase activation and recruitment domains (CARDs), are interaction motifs found in a wide array of proteins, typically those involved in processes relating to inflammation and apoptosis. These domains mediate the formation of larger protein complexes via direct interactions between individual CARDs. CARDs are found on a strikingly wide range of proteins, including helicases, kinases, mitochondrial proteins, caspases, and other cytoplasmic factors.
Basic features
CARDs are a subclass of protein motif known as the death fold, which features an arrangement of six to seven antiparallel alpha helices with a hydrophobic core and an outer face composed of charged residues. Other motifs in this class include the pyrin domain (PYD), death domain (DD), and death effector domain (DED), all of which also function primarily in regulation of apoptosis and inflammatory responses.
In apoptosis
CARDs were originally characterized based on their involvement in the regulation of caspase activation and apoptosis. The basic six-helix structure of the domain appears to be conserved as far back as the ced-3 and ced-4 genes in C. elegans, the organism in which several components of the apoptotic machinery were first characterized. CARDs are present on a number of proteins that promote apoptosis, primarily caspases 1,2,4,5,9, and 15 in mammals.
In the mammalian immune response
IL-1 and IL-18 processing
A number of CARDs have been shown to play a role in regulating inflammation in response to bacterial and viral pathogens as well as to a variety of endogenous stress signals. Recently, studies on the NLR protein Ipaf-1 have provided insight into how CARDs participate in the immune response. Ipaf-1 features an N-terminal CARD, a nucleotide-binding domain, and C-terminal leucine-rich repeats (LRRs), thought to function in a similar fashion to those found in Toll-like receptors. The primary role of this molecule appears to be regulation of the prote
|
https://en.wikipedia.org/wiki/Segal%27s%20conjecture
|
Segal's Burnside ring conjecture, or, more briefly, the Segal conjecture, is a theorem in homotopy theory, a branch of mathematics. The theorem relates the Burnside ring of a finite group G to the stable cohomotopy of the classifying space BG. The conjecture was made in the mid 1970s by Graeme Segal and proved in 1984 by Gunnar Carlsson. , this statement is still commonly referred to as the Segal conjecture, even though it now has the status of a theorem.
Statement of the theorem
The Segal conjecture has several different formulations, not all of which are equivalent. Here is a weak form: there exists, for every finite group G, an isomorphism
Here, lim denotes the inverse limit, S* denotes the stable cohomotopy ring, B denotes the classifying space, the superscript k denotes the k-skeleton, and the subscript + denotes the addition of a disjoint basepoint. On the right-hand side, the hat denotes the completion of the Burnside ring with respect to its augmentation ideal.
The Burnside ring
The Burnside ring of a finite group G is constructed from the category of finite G-sets as a Grothendieck group. More precisely, let M(G) be the commutative monoid of isomorphism classes of finite G-sets, with addition the disjoint union of G-sets and identity element the empty set (which is a G-set in a unique way). Then A(G), the Grothendieck group of M(G), is an abelian group. It is in fact a free abelian group with basis elements represented by the G-sets G/H, where H varies over the subgroups of G. (Note that H is not assumed here to be a normal subgroup of G, for while G/H is not a group in this case, it is still a G-set.) The ring structure on A(G) is induced by the direct product of G-sets; the multiplicative identity is the (isomorphism class of any) one-point set, which becomes a G-set in a unique way.
The Burnside ring is the analogue of the representation ring in the category of finite sets, as opposed to the category of finite-dimensional vector spaces over a field
|
https://en.wikipedia.org/wiki/HP%20250
|
The HP 250 was a multiuser business computer by Hewlett-Packard running HP 250 BASIC language as its OS with access to HP's IMAGE database management. It was produced by the General Systems Division (GSD), but was a major repackaging of desktop workstation HP 9835 which had been sold in small business configurations. The HP 9835's processor was initially used in the first HP 250s.
The HP 250 borrowed the embedded keyboard design from the HP 300 and added a wider slide-able and tilt-able monitor with screen labeled function keys buttons physically placed just below on-screen labels (a configuration now used in ATMs and gas pumps) built into a large desk design.
Though the HP 250 had a different processor and operating system, it used similar interface cards to the HP 300, and then later also the HP 3000 models 30, 33, 40, 42, 44, and 48: HP-IB channel (GIC), Network, and serial (MUX) cards. Usually the HP250 was a small HP-IB single channel system (limited to seven HP-IB devices per GIC at a less than 1 MHz bandwidth).
Initially the HP 250 was like the HP300 as a single user, floppy based computer system. Later a multi-user ability was added, and the HP300's embedded hard drive was installed as a boot drive. Additionally, drivers were made available to connect and use more HP-IB devices: hard disc and tape drives, plus impact and matrix printers. This gave some business-growth scale-ability to the HP250 product line.
The HP 250 was advertised in 1978 and was promoted more in Europe as an easy-to-use, small space, low cost business system, and thus sold better in Europe. The next-gen HP 250 was the HP 260 which lost the table, embedded keyboard, and CRT for a small stand-alone box.
HP systems moved away from all-in-one table top designs to having the system in a remote secure location, and remotely connecting user's terminals and peripherals out to in their work area. In those days, RS-232 cables ran from desk side terminals (262x low cost terminals) to the HP 25
|
https://en.wikipedia.org/wiki/Effective%20evolutionary%20time
|
The hypothesis of effective evolutionary time attempts to explain gradients, in particular latitudinal gradients, in species diversity. It was originally named "time hypothesis".
Background
Low (warm) latitudes contain significantly more species than high (cold) latitudes. This has been shown for many animal and plant groups, although exceptions exist (see latitudinal gradients in species diversity). An example of an exception is helminths of marine mammals, which have the greatest diversity in northern temperate seas, possibly because of small population densities of hosts in tropical seas that prevented the evolution of a rich helminth fauna, or because they originated in temperate seas and had more time for speciations there. It has become more and more apparent that species diversity is best correlated with environmental temperature and more generally environmental energy. These findings are the basis of the hypothesis of effective evolutionary time. Species have accumulated fastest in areas where temperatures are highest. Mutation rates and speed of selection due to faster physiological rates are highest, and generation times which also determine speed of selection, are smallest at high temperatures. This leads to a faster accumulation of species, which are absorbed into the abundantly available vacant niches, in the tropics. Vacant niches are available at all latitudes, and differences in the number of such niches can therefore not be the limiting factor for species richness. The hypothesis also incorporates a time factor: habitats with a long undisturbed evolutionary history will have greater diversity than habitats exposed to disturbances in evolutionary history.
The hypothesis of effective evolutionary time offers a causal explanation of diversity gradients, although it is recognized that many other factors can also contribute to and modulate them.
Historical aspects
Some aspects of the hypothesis are based on earlier studies. Bernhard Rensch, for exam
|
https://en.wikipedia.org/wiki/Metatarsophalangeal%20joints
|
The metatarsophalangeal joints (MTP joints), also informally known as toe knuckles, are the joints between the metatarsal bones of the foot and the proximal bones (proximal phalanges) of the toes. They are condyloid joints, meaning that an elliptical or rounded surface (of the metatarsal bones) comes close to a shallow cavity (of the proximal phalanges).
The ligaments are the plantar and two collateral.
Movements
The movements permitted in the metatarsophalangeal joints are flexion, extension, abduction, adduction and circumduction.
See also
Bunion
Hallux rigidus (stiff big toe)
Metatarsophalangeal joint sprain (turf toe)
|
https://en.wikipedia.org/wiki/Lateral%20condyle%20of%20tibia
|
The lateral condyle is the lateral portion of the upper extremity of tibia.
It serves as the insertion for the biceps femoris muscle (small slip). Most of the tendon of the biceps femoris inserts on the fibula.
See also
Gerdy's tubercle
Medial condyle of tibia
Additional images
|
https://en.wikipedia.org/wiki/Medial%20condyle%20of%20tibia
|
The medial condyle is the medial (or inner) portion of the upper extremity of tibia.
It is the site of insertion for the semimembranosus muscle.
See also
Lateral condyle of tibia
Medial collateral ligament
Additional images
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.