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https://en.wikipedia.org/wiki/Coloured%20Book%20protocols | The Coloured Book protocols were a set of communication protocols for computer networks developed in the United Kingdom in the 1970s. These protocols were designed to enable communication and data exchange between different computer systems and networks. The name originated with each protocol being identified by the colour of the cover of its specification document. The protocols were in use until the 1990s when the Internet protocol suite came into widespread use.
History
In the mid-1970s, the British Post Office Telecommunications division (BPO-T) worked with the academic community in the United Kingdom and the computer industry to develop a set of standards to enable interoperability among different computer systems based on the X.25 protocol suite for packet-switched wide area network (WAN) communication. First defined in 1975, the standards evolved through experience developing protocols for the NPL network in the late 1960s and the Experimental Packet Switched Service in the early 1970s.
The Coloured Book protocols were used on SERCnet from 1980, and SWUCN from 1982, both of which became part of the JANET academic network from 1984. The protocols were influential in the development of computer networks, particularly in the UK, gained some acceptance internationally as the first complete X.25 standard, and gave the UK "several years lead over other countries".
From late 1991, Internet protocols were adopted on the Janet network instead; they were operated simultaneously for a while, until X.25 support was phased out entirely in August 1997.
Protocols
The standards were defined in several documents, each addressing different aspects of computer network communication. They were identified by the colour of the cover:
Pink Book
The Pink Book defined protocols for transport over Ethernet. The protocol was basically X.25 level 3 running over LLC2.
Orange Book
The Orange Book defined protocols for transport over local networks using the Cambridge Ring (computer |
https://en.wikipedia.org/wiki/Wirecast | Wirecast is a live video streaming production tool by Telestream. It allows users to create live or on-demand broadcasts for the web.
Wirecast is a software video switcher, controlling real-time switching between multiple live video cameras, while dynamically mixing in other source media, such as QuickTime movies, music, audio and slides to create professional broadcast productions for live or on-demand distribution on the web.
Specifications
Can broadcast to multiple services at once
Support for multiple cameras
Chroma key (blue/green screen)
Scene transitions
Built-in lower-third titling
Desktop Presenter - makes Macintosh or Windows Desktop available as a source
H.264
3D Graphics
QuickTime Streaming Server Support
Keynote Integration
Multiple Layers
Multiple Broadcast Support, when ready to go live, it provides direct integration with a number of streaming service providers.
A direct integration with Limelight Networks, adds support for Flash streaming
Adds a built-in streaming service access from Ustream.
Encoding support for Nvidia NVENC and Intel Quick Sync Video
Support for Network Device Interface
Rendezvous Videoconferencing feature allows users to bring in live video feeds from multiple sources, including remote locations. |
https://en.wikipedia.org/wiki/Peter%E2%80%93Weyl%20theorem | In mathematics, the Peter–Weyl theorem is a basic result in the theory of harmonic analysis, applying to topological groups that are compact, but are not necessarily abelian. It was initially proved by Hermann Weyl, with his student Fritz Peter, in the setting of a compact topological group G . The theorem is a collection of results generalizing the significant facts about the decomposition of the regular representation of any finite group, as discovered by Ferdinand Georg Frobenius and Issai Schur.
Let G be a compact group. The theorem has three parts. The first part states that the matrix coefficients of irreducible representations of G are dense in the space C(G) of continuous complex-valued functions on G, and thus also in the space L2(G) of square-integrable functions. The second part asserts the complete reducibility of unitary representations of G. The third part then asserts that the regular representation of G on L2(G) decomposes as the direct sum of all irreducible unitary representations. Moreover, the matrix coefficients of the irreducible unitary representations form an orthonormal basis of L2(G). In the case that G is the group of unit complex numbers, this last result is simply a standard result from Fourier series.
Matrix coefficients
A matrix coefficient of the group G is a complex-valued function on G given as the composition
where π : G → GL(V) is a finite-dimensional (continuous) group representation of G, and L is a linear functional on the vector space of endomorphisms of V (e.g. trace), which contains GL(V) as an open subset. Matrix coefficients are continuous, since representations are by definition continuous, and linear functionals on finite-dimensional spaces are also continuous.
The first part of the Peter–Weyl theorem asserts (; ):
Peter–Weyl Theorem (Part I). The set of matrix coefficients of G is dense in the space of continuous complex functions C(G) on G, equipped with the uniform norm.
This first result resembles the Sto |
https://en.wikipedia.org/wiki/Geli%20%28software%29 | geli is a block device-layer disk encryption system written for FreeBSD, introduced in version 6.0. It uses the GEOM disk framework. It was designed and implemented by Paweł Jakub Dawidek.
Design details
geli was initially written to protect data on a user's computer in situations of physical theft of hardware, disallowing the thief access to the protected data. This has changed over time with the introduction of optional data authentication/integrity verification.
geli allows the key to consist of several information components (a user entered passphrase, random bits from a file, etc.), permits multiple keys (a user key and a company key, for example) and can attach a provider with a random, one-time key. The user passphrase is strengthened with PKCS#5.
Differences from GBDE
The geli utility is different from gbde in that it offers different features and uses a different scheme for doing cryptographic work. It supports the crypto framework within FreeBSD, allowing hardware cryptographic acceleration if available, as well as supporting more cryptographic algorithms (currently AES, Triple DES, Blowfish and Camellia) and data authentication/integrity verification via MD5, SHA1, RIPEMD160, SHA256, SHA384 or SHA512 as Hash Message Authentication Codes.
See also
GBDE
LUKS
Disk encryption
Disk encryption software
Comparison of disk encryption software |
https://en.wikipedia.org/wiki/Period-doubling%20bifurcation | In dynamical systems theory, a period-doubling bifurcation occurs when a slight change in a system's parameters causes a new periodic trajectory to emerge from an existing periodic trajectory—the new one having double the period of the original. With the doubled period, it takes twice as long (or, in a discrete dynamical system, twice as many iterations) for the numerical values visited by the system to repeat themselves.
A period-halving bifurcation occurs when a system switches to a new behavior with half the period of the original system.
A period-doubling cascade is an infinite sequence of period-doubling bifurcations. Such cascades are a common route by which dynamical systems develop chaos. In hydrodynamics, they are one of the possible routes to turbulence.
Examples
Logistic map
The logistic map is
where is a function of the (discrete) time . The parameter is assumed to lie in the interval , in which case is bounded on .
For between 1 and 3, converges to the stable fixed point . Then, for between 3 and 3.44949, converges to a permanent oscillation between two values and that depend on . As grows larger, oscillations between 4 values, then 8, 16, 32, etc. appear. These period doublings culminate at , beyond which more complex regimes appear. As increases, there are some intervals where most starting values will converge to one or a small number of stable oscillations, such as near .
In the interval where the period is for some positive integer , not all the points actually have period . These are single points, rather than intervals. These points are said to be in unstable orbits, since nearby points do not approach the same orbit as them.
quadratic map
Real version of complex quadratic map is related with real slice of the Mandelbrot set.
Kuramoto–Sivashinsky equation
The Kuramoto–Sivashinsky equation is an example of a spatiotemporally continuous dynamical system that exhibits period doubling. It is one of the most well-studied nonlin |
https://en.wikipedia.org/wiki/MASS%20syndrome | MASS syndrome is a medical disorder of the connective tissue similar to Marfan syndrome.
MASS stands for mitral valve prolapse, aortic root diameter at upper limits of normal for body size, stretch marks of the skin, and skeletal conditions similar to Marfan syndrome. It is caused by a mutation in the FBN1 gene, which encodes fibrillin-1. Fibrillin-1 is an extracellular matrix protein that is found in microfibrils; defects in the fibrillin-1 protein cause the malfunctioning of microfibrils, which results in improper stretching of ligaments, blood vessels, and skin.
Treatment options for MASS syndrome are largely determined on a case-by-case basis and generally address the symptoms as opposed to the cause of the disorder. Due to the similarities between MASS syndrome and Marfan syndrome, the treatment plans are also similar.
Other possible symptoms are mitral valve prolapse, a large aortic root diameter, and myopia. The skeletal features found in MASS syndrome include curvature of the spine (scoliosis), chest wall deformities, and joint hypermobility.
MASS syndrome and Marfan syndrome are overlapping connective tissue disorders. Both can be caused by mutations in the gene encoding a protein called fibrillin. These conditions share many of the same signs and symptoms including long limbs and fingers, chest wall abnormalities (indented chest bone or protruding chest bone), flat feet, scoliosis, mitral valve prolapse, loose or hypextensible joints, highly arched roof of the mouth, and mild dilatation of the aortic root. Unlike in Marfan syndrome, aneurysm does not develop.
Individuals with MASS syndrome do not have progressive aortic enlargement or lens dislocation, while people with Marfan syndrome do. Skin involvement in MASS syndrome is typically limited to stretch marks (striae distensae). Also, the skeletal manifestations of MASS syndrome are generally mild. |
https://en.wikipedia.org/wiki/Keiichi%20Itakura | is an organic chemist and a Professor in the Department of Molecular and Cellular Biology at the Beckman Research Institute at City of Hope National Medical Center.
Biography
Itakura was born in Tokyo, Japan on February 18, 1942. He obtained a PhD in Organic Chemistry at Tokyo Pharmaceutical College in 1970. He then accepted a fellowship with Saran A. Narang at the Division of Biological Sciences, National Research Council of Canada, to work on DNA synthesis.
In 1975, Itakura joined the City of Hope National Medical Center. There he was part of a team of scientists including Arthur Riggs who developed recombinant DNA technology. By 1976, the first artificial gene had been synthesized, by Har Gobind Khorana at MIT, and the possibility of synthesizing insulin through bacterial fermentation by incorporating a gene for insulin into a bacterium such as E. coli had been suggested.
Itakura and others succeeded in synthesizing a plasmid containing chemically synthesized lac operator in 1976, using a technique they called "linker technology".
In 1977, Itakura successfully synthesized the gene for somatostatin. Production of somatostatin, a hormone produced in the human brain, was not expected to be commercially significant. However, the work was considered a possible first step towards the creation of a synthetic insulin. Building on Khorana's work, Itakura developed a technique that reduced the time involved in successful synthesis from years to weeks. He then inserted the gene for somatostatin into E. coli. This was the first demonstration of a foreign gene inserted into E. coli.
By 1978 Herbert Boyer's biotechnology startup Genentech had contracted with Riggs and Itakura, and Boyer and Itakura had created a plasmid coded for human insulin. Genentech signed a joint-venture agreement with Eli Lilly and Company to develop and market the technology. Their product, Humulin, approved in 1982 by the FDA, was the first biotechnology product to be marketed. Genentech |
https://en.wikipedia.org/wiki/Haig%E2%80%93Simons%20income | Haig–Simons income or Schanz–Haig–Simons income is an income measure used by public finance economists to analyze economic well-being which defines income as consumption plus change in net worth. It is represented by the mathematical formula:
I = C + ΔNW
where C = consumption and ΔNW = change in net worth.
Consumption refers to the money spent on goods and services of any kind. From a perfect theory view, consumption does not include capital expenditures, and the full spending would be amortized.
History
The measure of the income tax base equal to the sum of consumption and change in net worth was first advocated by German legal scholar Georg von Schanz. His concept was further developed by the American economists Robert M. Haig and Henry C. Simons in the 1920s and 1930s.
Haig defined personal income as "the money value of the net accretion to one's economic power between two points of time," a formulation that was intended to include the taxpayer's consumption.
That was thought by Simons to be interchangeable with his own formulation:
"Personal income may be defined as "the algebraic sum of (1) the market value of rights exercised in consumption and (2) the change in the value of the store of property rights between the beginning and end of the period in question."
In this concept, all inflows and outflows of resources are considered taxable income in a broad sense, including donations and windfall gains.
Schanz–Haig–Simons income tax vs. cash-flow consumption tax
A cash-flow consumption tax is intended to confine the cash-flow tax burden to an individual's annual consumption and to remove nonconsumption expenses and current savings from the tax base. The base is calculated by combining the year's gross receipts and savings withdrawals, and then subtracting the year's business and investment expenses and the year's additions to savings. Progressive rates are applied to the resulting sum.
By contrast, the base for a theoretically correct Schanz–Haig–Simo |
https://en.wikipedia.org/wiki/Doris%20Schattschneider | Doris J. Schattschneider (née Wood) is an American mathematician, a retired professor of mathematics at Moravian College. She is known for writing about tessellations and about the art of M. C. Escher, for helping Martin Gardner validate and popularize the pentagon tiling discoveries of amateur mathematician Marjorie Rice, and for co-directing with Eugene Klotz the project that developed The Geometer's Sketchpad.
Biography
Schattschneider was born in Staten Island; her mother, Charlotte Lucile Ingalls Wood, taught Latin and was herself the daughter of a Staten Island school principal, and her father, Robert W. Wood, Jr., was an electrical engineer who worked for the New York City Bureau of Bridge Design. Her family moved to Lake Placid, New York during World War II, while her father served as an engineer for the U. S. Army; she began her schooling in Lake Placid, but returned to Staten Island after the war. She did her undergraduate studies in mathematics at the University of Rochester, and earned a Ph.D. in 1966 from Yale University under the joint supervision of Tsuneo Tamagawa and Ichirô Satake; her thesis, in abstract algebra, concerned semisimple algebraic groups. She taught at Northwestern University for a year and at the University of Illinois at Chicago Circle for three years before joining the faculty of Moravian College in 1968, where she remained for 34 years until her retirement. She was the first female editor of Mathematics Magazine, from 1981 to 1985.
She was married for 54 years to the Rev. Dr. David A. Schattschneider (1939-2016), a church historian and Dean of Moravian Theological Seminary; their daughter Laura Ellen Schattschneider is a lawyer.
Involvement with Marjorie Rice
By February 1976, Marjorie Rice had discovered a new pentagon type and its variations in shape and drew up several tessellations by these pentagon tiles. She mailed her discoveries to Martin Gardner using her own home-made notation. He, in turn, sent Rice's work to Schattsc |
https://en.wikipedia.org/wiki/Natural%20surveillance | Natural surveillance is a term used in Crime Prevention Through Environmental Design (CPTED) models for crime prevention. These models rely on the ability to influence offender decisions preceding criminal acts. Research into criminal behavior demonstrates that the decision to offend or not to offend is more influenced by cues to the perceived risk of being caught than by cues to reward or ease of entry. Consistent with this research CPTED-based strategies emphasize enhancing the perceived risk of detection and apprehension.
Natural surveillance limits the opportunity for crime by taking steps to increase the perception that people can be seen. Natural surveillance occurs by designing the placement of physical features, activities and people in such a way as to maximize visibility and foster positive social interaction. Potential offenders feel increased scrutiny and perceive few escape routes. Natural surveillance is typically free of cost, however its effectiveness to deter crime varies with the individual offender.
Jane Jacobs, North American editor, urban activist, urban planning critic, and author of The Death and Life of Great American Cities (1961), formulated the natural surveillance strategy — eyes on the street, as she called it — based on her work in New York's Greenwich Village. As people are moving around an area, they will be able to observe what is going on around them, provided the area is open and well lit. Supporting a diversity of uses within a public space is highly effective. Other ways to promote natural surveillance include low landscaping, street lights, street designs that encourage pedestrian use, removing hiding and lurking places, and placing high risk targets, such as expensive or display items, in plain view of legitimate users, such as near a receptionist or sales clerk.
Included in the design are features that maximize visibility of people, parking areas and building entrances: doors and windows that look out on to streets and park |
https://en.wikipedia.org/wiki/Woolrich%20Electrical%20Generator | The Woolrich Electrical Generator, now in Thinktank, Birmingham Science Museum, England, is the earliest electrical generator used in an industrial process. Built in February 1844 at the Magneto Works of Thomas Prime and Son, Birmingham, to a design by John Stephen Woolrich (1820–1850), it was used by the firm of Elkingtons for commercial electroplating.
Plaque
The generator stood for some time in the chapel of Aston Hall, accompanied by a plaque bearing the following inscription:
Construction
The generator in its surviving form consists of 8 axial bobbins with a magnetic field applied by 4 iron horseshoe magnets. The rectangular frame was made of wood and measured 5 foot 4 inches tall, 6 feet wide, and 2 feet long. The generator was fitted with a commutator, as electroplating requires direct current.
John Stephen Woolrich
The generator's designer, John Stephen Woolrich, was born in Lichfield, England in late 1820. The second son of John Woolrich (c.1791–1843) and his wife Mary Woolrich (formerly Egginton), he was baptised at St Mary's Church, Lichfield on 6 November 1820.
In August 1842 he was granted patent number 9431 for the use of a magneto-electrical machine (instead of batteries) in electroplating, and the use of gold sulphite and silver sulphite as electrolytes. He offered to sell the rights to Elkingtons for the enormous sum of £15,000; they declined, and after some heated correspondence eventually, in May 1845, agreed to pay Woolrich £100 initially and then £400 annually for the rest of the term of the patent. Woolrich later relicensed the patent himself to use in his own Magneto-Plating and Gilding Works in Great Charles Street, Birmingham, and in 1849 was listed as a "chemist & magneto-plater & gilder", residing at 12 James Street, just off St Paul's Square in the Jewellery Quarter.
He died at the age of 29 in early 1850, and was buried at St Bartholomew's Church, Edgbaston on 4 March 1850.
The elder John Woolrich is listed in the United Kingdom C |
https://en.wikipedia.org/wiki/Genetic%20Studies%20of%20Genius | The Genetic Studies of Genius, later known as the Terman Study of the Gifted, is the oldest and longest-running longitudinal study in the field of psychology. It was begun by Lewis Terman at Stanford University in 1921 to examine the development and characteristics of gifted children into adulthood.
The results from the study have been published in five books, a monograph, and dozens of articles. A related retrospective study of eminent men in history by Catharine Cox, though not part of the longitudinal study, was published as part of the Genetic Studies of Genius. It further inspired the ongoing Study of Mathematically Precocious Youth longitudinal study.
Origin
Terman had previously performed studies in intelligence, including his doctoral dissertation. In 1916, he adapted Alfred Binet's intelligence test for the United States and expanded its range. The result was the Stanford–Binet Intelligence Scales, which are still in use today (in an updated form). After his service in developing the Army Alpha during World War I, Terman returned to Stanford in order to start his study.
Terman had already found some bright children through his earlier research, and some of these were part of the sample in the Genetic Studies of Genius. He hired several assistants, including Florence Goodenough and Catharine Cox, to search the public schools of California for similarly gifted children. Terman initially hoped to find the 1,000 most intelligent children, but eventually found 1,444. However, Terman gradually added subjects to the study through 1928 until there were 1,528 (856 males and 672 females). Not all subjects were discovered with the Stanford–Binet. Some were selected for the study with the National Intelligence Tests and the Army Alpha. The study subjects were born between 1900 and 1925, all lived in California, were 95–99% white, and the majority came from upper- or middle-class families.
Early findings
Terman's goal was to disprove the then-current belief tha |
https://en.wikipedia.org/wiki/Elektronika%20VM-12 | Elektronika VM-12 was the first Soviet VHS-compatible videocassette recorder. It was capable to record SECAM-IIIB D/K (OIRT), PAL and black-and-white video on a 12,65-mm wide magnetic tape.
Elektronika VM-12 was 480х367х136 mm in size and weighted 10 kg.
PAL SP - 2,339±0,5% |
https://en.wikipedia.org/wiki/Beneficial%20acclimation%20hypothesis | The beneficial acclimation hypothesis (BAH) is the physiological hypothesis that acclimating to a particular environment (usually thermal) provides an organism with advantages in that environment. First formally tested by Armand Marie Leroi, Albert Bennett, and Richard Lenski in 1994, it has however been a central assumption in historical physiological work that acclimation is adaptive. Further refined by Raymond B. Huey and David Berrigan under the strong inference approach, the hypothesis has been falsified as a general rule by a series of multiple hypotheses experiments.
History and definition
Acclimation is a set of physiological responses that occurs during an individual's lifetime to chronic laboratory-induced environmental conditions (in contrast to acclimatization). It is one component of adaptation. While physiologists have traditionally assumed that acclimation is beneficial (or explicitly defined it as such), criticism of the adaptationist program by Stephen Jay Gould and Richard Lewontin led to a call for increased robustness in testing adaptationist hypotheses.
The initial definition of the BAH, as published in 1994 in the Proceedings of the National Academy of Sciences by Leroi et al., is that "acclimation to a particular environment gives an organism a performance advantage in that environment over another organism that has not had the opportunity to acclimate to that particular environment." This definition was further reworked in an article in American Zoologist 1999 by Raymond B. Huey, David Berrigan, George W. Gilchrist, and Jon C. Herron. They determined that, following Platt's strong inference approach, multiple competing hypotheses were needed to properly assess beneficial acclimation. These included:
1. Beneficial Acclimation. Acclimating to a particular environment confers fitness advantages in that environment.
2. Optimal Developmental Temperature. There is an ideal temperature to develop at so individuals reared at an optimal temp |
https://en.wikipedia.org/wiki/Scottish%20Built%20Ships%20database | The Scottish Built Ships database is a free-to-use record of over 35,000 ships built in Scotland. It was renamed from the "Clyde Built Ships" database when its scope was extended to cover the whole country's ship and boatbuilders.
With a standard format, the extent of information varies from ship to ship, and additional information is being continually added by a team of voluntary editors. The records can be easily searched from a search page.
External links
Scottish built ships database
Ships built in Scotland
Online archives
Maritime history of Scotland
Ship databases
Online databases
Databases in Scotland
Shipbuilding in Scotland |
https://en.wikipedia.org/wiki/Linear%20subspace | In mathematics, and more specifically in linear algebra, a linear subspace or vector subspace is a vector space that is a subset of some larger vector space. A linear subspace is usually simply called a subspace when the context serves to distinguish it from other types of subspaces.
Definition
If V is a vector space over a field K and if W is a subset of V, then W is a linear subspace of V if under the operations of V, W is a vector space over K. Equivalently, a nonempty subset W is a linear subspace of V if, whenever are elements of W and are elements of K, it follows that is in W.
As a corollary, all vector spaces are equipped with at least two (possibly different) linear subspaces: the zero vector space consisting of the zero vector alone and the entire vector space itself. These are called the trivial subspaces of the vector space.
Examples
Example I
In the vector space V = R3 (the real coordinate space over the field R of real numbers), take W to be the set of all vectors in V whose last component is 0.
Then W is a subspace of V.
Proof:
Given u and v in W, then they can be expressed as and . Then . Thus, u + v is an element of W, too.
Given u in W and a scalar c in R, if again, then . Thus, cu is an element of W too.
Example II
Let the field be R again, but now let the vector space V be the Cartesian plane R2.
Take W to be the set of points (x, y) of R2 such that x = y.
Then W is a subspace of R2.
Proof:
Let and be elements of W, that is, points in the plane such that p1 = p2 and q1 = q2. Then ; since p1 = p2 and q1 = q2, then p1 + q1 = p2 + q2, so p + q is an element of W.
Let p = (p1, p2) be an element of W, that is, a point in the plane such that p1 = p2, and let c be a scalar in R. Then ; since p1 = p2, then cp1 = cp2, so cp is an element of W.
In general, any subset of the real coordinate space Rn that is defined by a system of homogeneous linear equations will yield a subspace.
(The equation in example I was z = 0, and the equation in ex |
https://en.wikipedia.org/wiki/Biogenic%20sulfide%20corrosion | Biogenic sulfide corrosion is a bacterially mediated process of forming hydrogen sulfide gas and the subsequent conversion to sulfuric acid that attacks concrete and steel within wastewater environments. The hydrogen sulfide gas is biochemically oxidized in the presence of moisture to form sulfuric acid. The effect of sulfuric acid on concrete and steel surfaces exposed to severe wastewater environments can be devastating. In the USA alone, corrosion is causing sewer asset losses estimated at $14 billion per year. This cost is expected to increase as the aging infrastructure continues to fail.
Environment
Corrosion may occur where stale sewage generates hydrogen sulfide gas into an atmosphere containing oxygen gas and high relative humidity. There must be an underlying anaerobic aquatic habitat containing sulfates and an overlying aerobic aquatic habitat separated by a gas phase containing both oxygen and hydrogen sulfide at concentrations in excess of 2 ppm.
Conversion of sulfate SO42− to hydrogen sulfide H2S
Fresh domestic sewage entering a wastewater collection system contains proteins including organic sulfur compounds oxidizable to sulfates and may contain inorganic sulfates. Dissolved oxygen is depleted as bacteria begin to catabolize organic material in sewage. In the absence of dissolved oxygen and nitrates, sulfates are reduced to hydrogen sulfide as an alternative source of oxygen for catabolizing organic waste by sulfate reducing bacteria (SRB), identified primarily from the obligate anaerobic species Desulfovibrio.
Hydrogen sulfide production depends on various physicochemical, topographic and hydraulic parameters such as:
Sewage oxygen concentration. The threshold is 0.1 mg.l−1; above this value, sulfides produced in sludge and sediments are oxidized by oxygen; below this value, sulfides are emitted in the gaseous phase.
Temperature. The higher the temperature, the faster the kinetics of H2S production.
Sewage pH. It must be included between |
https://en.wikipedia.org/wiki/IATA%20airport%20code | An IATA airport code, also known as an IATA location identifier, IATA station code, or simply a location identifier, is a three-letter geocode designating many airports and metropolitan areas around the world, defined by the International Air Transport Association (IATA). The characters prominently displayed on baggage tags attached at airport check-in desks are an example of a way these codes are used.
The assignment of these codes is governed by IATA Resolution 763, and it is administered by the IATA's headquarters in Montreal, Canada. The codes are published semi-annually in the IATA Airline Coding Directory.
IATA provides codes for airport handling entities, and for certain railway stations.
Alphabetical lists of airports sorted by IATA code are available. A list of railway station codes, shared in agreements between airlines and rail lines such as Amtrak, SNCF, and , is available. However, many railway administrations have their own list of codes for their stations, such as the list of Amtrak station codes.
History
Airport codes arose out of the convenience that the practice brought pilots for location identification in the 1930s. Initially, pilots in the United States used the two-letter code from the National Weather Service (NWS) for identifying cities. This system became unmanageable for cities and towns without an NWS identifier, and the use of two letters allowed only a few hundred combinations; a three-letter system of airport codes was implemented. This system allowed for 17,576 permutations, assuming all letters can be used in conjunction with each other.
Naming conventions
National policies
United States
Since the U.S. Navy reserved "N" codes, and to prevent confusion with Federal Communications Commission broadcast call signs, which begin with "W" or "K", the airports of certain U.S. cities whose names begin with one of these letters had to adopt "irregular" airport codes:
EWR for Newark, New Jersey,
HVN for New Haven, Connecticut, ORF for N |
https://en.wikipedia.org/wiki/Tur%C3%A1n%27s%20method | In mathematics, Turán's method provides lower bounds for exponential sums and complex power sums. The method has been applied to problems in equidistribution.
The method applies to sums of the form
where the b and z are complex numbers and ν runs over a range of integers. There are two main results, depending on the size of the complex numbers z.
Turán's first theorem
The first result applies to sums sν where for all n. For any range of ν of length N, say ν = M + 1, ..., M + N, there is some ν with |sν| at least c(M, N)|s0| where
The sum here may be replaced by the weaker but simpler .
We may deduce the Fabry gap theorem from this result.
Turán's second theorem
The second result applies to sums sν where for all n. Assume that the z are ordered in decreasing absolute value and scaled so that |z1| = 1. Then there is some ν with
See also
Turán's theorem in graph theory |
https://en.wikipedia.org/wiki/Population%20health | Population health has been defined as "the health outcomes of a group of individuals, including the distribution of such outcomes within the group". It is an approach to health that aims to improve the health of an entire human population. It has been described as consisting of three components. These are "health outcomes, patterns of health determinants, and policies and interventions".
A priority considered important in achieving the aim of population health is to reduce health inequities or disparities among different population groups due to, among other factors, the social determinants of health (SDOH). The SDOH include all the factors (social, environmental, cultural and physical) that the different populations are born into, grow up and function with throughout their lifetimes which potentially have a measurable impact on the health of human populations. The population health concept represents a change in the focus from the individual-level, characteristic of most mainstream medicine. It also seeks to complement the classic efforts of public health agencies by addressing a broader range of factors shown to impact the health of different populations. The World Health Organization's Commission on Social Determinants of Health, reported in 2008, that the SDOH factors were responsible for the bulk of diseases and injuries and these were the major causes of health inequities in all countries. In the US, SDOH were estimated to account for 70% of avoidable mortality.
From a population health perspective, health has been defined not simply as a state free from disease but as "the capacity of people to adapt to, respond to, or control life's challenges and changes". The World Health Organization (WHO) defined health in its broader sense in 1946 as "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity."
Healthy People 2020
Healthy People 2020 is a web site sponsored by the US Department of Health and Human |
https://en.wikipedia.org/wiki/Ultra-high%20vacuum | Ultra-high vacuum (often spelled ultrahigh in American English, UHV) is the vacuum regime characterised by pressures lower than about . UHV conditions are created by pumping the gas out of a UHV chamber. At these low pressures the mean free path of a gas molecule is greater than approximately 40 km, so the gas is in free molecular flow, and gas molecules will collide with the chamber walls many times before colliding with each other. Almost all molecular interactions therefore take place on various surfaces in the chamber.
UHV conditions are integral to scientific research. Surface science experiments often require a chemically clean sample surface with the absence of any unwanted adsorbates. Surface analysis tools such as X-ray photoelectron spectroscopy and low energy ion scattering require UHV conditions for the transmission of electron or ion beams. For the same reason, beam pipes in particle accelerators such as the Large Hadron Collider are kept at UHV.
Overview
Maintaining UHV conditions requires the use of unusual materials for equipment. Useful concepts for UHV include:
Sorption of gases
Kinetic theory of gases
Gas transport and pumping
Vacuum pumps and systems
Vapour pressure
Typically, UHV requires:
High pumping speed — possibly multiple vacuum pumps in series and/or parallel
Minimized surface area in the chamber
High conductance tubing to pumps — short and fat, without obstruction
Use of low-outgassing materials such as certain stainless steels
Avoid creating pits of trapped gas behind bolts, welding voids, etc.
Electropolishing of all metal parts after machining or welding
Use of low vapor pressure materials (ceramics, glass, metals, teflon if unbaked)
Baking of the system to remove water or hydrocarbons adsorbed to the walls
Chilling of chamber walls to cryogenic temperatures during use
Avoiding all traces of hydrocarbons, including skin oils in a fingerprint — gloves must always be used
Hydrogen and carbon monoxide are the most common backg |
https://en.wikipedia.org/wiki/Anna%20Caulfield%20McKnight | Anna Caulfield McKnight (born Cascade, Michigan, November 22, 1866; died Grand Rapids, Michigan, June 18, 1947) was an American traveler, lecturer on art and travel, club woman, woman suffragist, and businesswoman. Her oratory and magic lantern slides taken on her travels made her a well-known lecturer in her time.
Early life
McKnight was born the daughter of John Caulfield (1838-1919), a prosperous Irish immigrant in Grand Rapids, Michigan, and his wife Esther Egan (1844-1923). The oldest of seven children, she was educated at Sacred Heart Academy in Detroit and the "Harvard Annex" (soon to be Radcliffe College) in Cambridge, Massachusetts. At the Harvard Annex she studied art history with scholar Charles Eliot Norton, who encouraged her to study in Europe. In 1892 she left for Europe, where she studied with archaeologist Giovanni Battista de Rossi and spent four years travelling.
Early lectures
Anna gave her first lectures after joining the Grand Rapids Ladies' Literary Club after her graduation from Sacred Heart Academy; friends suggested that she pursue lecturing as a career, and she went to the Harvard Annex with that in mind. In Europe she gave lectures and pursued material of interest, meeting with Pope Leo XIII for example (she later met Pope Benedict XV and Pope Pius XI). On her return to the United States, she lectured widely at institutions such as the Brooklyn Institute of Arts and Sciences, the Chicago Art Institute, and Vassar College; her lecture at the French embassy in Washington, DC so impressed President William Howard Taft that he invited Anna and her mother to visit him at his summer home on Lake Champlain. She also spoke at the 1898 biennial meeting of the General Federation of Women's Clubs in Denver, Colorado. She was appointed a member of the Fine Arts department at the Paris Exposition, 1900 by United States Commissioner-General Ferdinand Peck.
Married life
On August 20, 1907 Anna married Grand Rapids lawyer and businessman William F. M |
https://en.wikipedia.org/wiki/Cartan%27s%20theorems%20A%20and%20B | In mathematics, Cartan's theorems A and B are two results proved by Henri Cartan around 1951, concerning a coherent sheaf on a Stein manifold . They are significant both as applied to several complex variables, and in the general development of sheaf cohomology.
Theorem B is stated in cohomological terms (a formulation that Cartan (1953, p. 51) attributes to J.-P. Serre):
Analogous properties were established by Serre (1957) for coherent sheaves in algebraic geometry, when is an affine scheme. The analogue of Theorem B in this context is as follows :
These theorems have many important applications. For instance, they imply that a holomorphic function on a closed complex submanifold, , of a Stein manifold can be extended to a holomorphic function on all of . At a deeper level, these theorems were used by Jean-Pierre Serre to prove the GAGA theorem.
Theorem B is sharp in the sense that if for all coherent sheaves on a complex manifold (resp. quasi-coherent sheaves on a noetherian scheme ), then is Stein (resp. affine); see (resp. and ).
See also
Cousin problems |
https://en.wikipedia.org/wiki/Washlet | is a line of cleansing toilet seats manufactured and sold by the Japanese company Toto. They feature water spray features for genital and anal cleansing. The electronic bidet is commonplace on toilets in Japan. Released in June 1980, more than 30 million Washlets had been sold as of January 2011.
History
Toto's business model in the 1960s was to import American “wash air seats” for domestic sales. They were mainly sold to hospitals and nursing homes. Toto began domestic production in 1969, but wash air seats were initially expensive and sometimes caused scalding injuries because of poor regulation of water temperature.
Toto continued its own research and development, surveying 300 male and female employees to determine the appropriate spray positions, because there were no biometric statistics available.
Banking on the prospect that washlets would sell widely in Japan, Toto began to sell its own improved washlets in 1980. Its two models were the G series ("Gorgeous") that could store warm water, had a bidet and a dryer function, and toilet seat warming (the function of which is called "warmlet"); and the S series ("Standard)" that instantly turned cold water into warm water and was equipped with a bidet and a warmlet function. The two series have remained the basic product models to the present, along with a compact series introduced in 1993. The models initially included a regular size and an elongated size, depending on the configuration of the toilet to which washlets were attached, but were replaced by single-sized models in February 2012 with a few exceptions such as products for hotel usage.
Recognizing its pioneering role, in 2012, the initial model Washlet G was certified as item number 55 of Mechanical Engineering Heritage.
In a 1982 commercial that featured then-rising pop singer Jun Togawa, the advertising slogan “Our butt wants to be washed too” and unique background music quickly drew public attention to Toto's new product. As the commercial was |
https://en.wikipedia.org/wiki/Edith%20Elkind | Edith Elkind is an Estonian computer scientist who works as a professor of computing science at the University of Oxford and as a non-tutorial fellow of Balliol College, Oxford. She is known for her work in algorithmic game theory and computational social choice.
Education and career
As a high school student, Elkind competed for the Estonian team in the International Mathematical Olympiads in 1992 and 1993.
She earned a master's degree at Moscow State University in 1998, and completed her Ph.D. in 2005 from Princeton University. Her dissertation, Computational Issues in Optimal Auction Design, was supervised by Amit Sahai.
After completing her Ph.D., she was a postdoctoral researcher at the University of Warwick, the University of Liverpool, and the Hebrew University of Jerusalem. She became a lecturer at the University of Southampton and an assistant professor at Nanyang Technological University before moving to Oxford in 2013. She was awarded the title of professor by Oxford in 2016.
Book
With Georgios Chalkiadakis and Michael J. Wooldridge, Elkind is an author of Computational Aspects of Cooperative Game Theory (Morgan & Claypool, 2012). |
https://en.wikipedia.org/wiki/Tropical%20horticulture | Tropical horticulture is a branch of horticulture that studies and cultivates plants in the tropics, i.e., the equatorial regions of the world. The field is sometimes known by the portmanteau "TropHort".
Overview
Tropical horticulture includes plants such as perennial woody plants (arboriculture), ornamentals (floriculture), vegetables (olericulture), and fruits (pomology) including grapes (viticulture). The origin of many of these crops is not in the tropics but in temperate zones. Their adoption to tropical climatic conditions is an objective of breeding. Many important crops, however, are indigenous to the tropics. The latter embrace perennial crops such as oil palm, vegetables including okra, field crops such as rice and sugarcane, and particularly fruits including pineapple, banana, papaya, and mango.
Since the tropics represent 36 percent of the earth's surface and 20 percent of its land surface, the potential of tropical horticulture is huge. In contrast to temperate regions, environmental conditions in the tropics are defined less by seasonal temperature fluctuations and more by seasonality of precipitation. Thus the climate in the greater part of the tropics is characterized by distinct wet and dry seasons, although such variation is reduced in locations closer to the equator (±5° latitude). Temperature conditions in the tropics are affected by elevation, in which contrasting warmer and colder climate areas in the tropics can be differentiated, and highland areas in the tropics can consequently be more favourable for production of temperate plant species than are lowland areas.
Types of plants
Both vascular and non-vascular plants grow in tropical environments. Plants indigenous to the tropics are usually cold sensitive and adapted to receiving high levels of solar radiation. They are sensitive to small variations in photoperiod ("short day" plants), and can be adapted to extended drought, high precipitation and/or distinct wet and dry seasons. High ni |
https://en.wikipedia.org/wiki/Lorentz%20scalar | In a relativistic theory of physics, a Lorentz scalar is an expression, formed from items of the theory, which evaluates to a scalar, invariant under any Lorentz transformation. A Lorentz scalar may be generated from e.g., the scalar product of vectors, or from contracting tensors of the theory. While the components of vectors and tensors are in general altered under Lorentz transformations, Lorentz scalars remain unchanged.
A Lorentz scalar is not always immediately seen to be an invariant scalar in the mathematical sense, but the resulting scalar value is invariant under any basis transformation applied to the vector space, on which the considered theory is based. A simple Lorentz scalar in Minkowski spacetime is the spacetime distance ("length" of their difference) of two fixed events in spacetime. While the "position"-4-vectors of the events change between different inertial frames, their spacetime distance remains invariant under the corresponding Lorentz transformation. Other examples of Lorentz scalars are the "length" of 4-velocities (see below), or the Ricci curvature in a point in spacetime from General relativity, which is a contraction of the Riemann curvature tensor there.
Simple scalars in special relativity
The length of a position vector
In special relativity the location of a particle in 4-dimensional spacetime is given by
where is the position in 3-dimensional space of the particle, is the velocity in 3-dimensional space and is the speed of light.
The "length" of the vector is a Lorentz scalar and is given by
where is the proper time as measured by a clock in the rest frame of the particle and the Minkowski metric is given by
This is a time-like metric.
Often the alternate signature of the Minkowski metric is used in which the signs of the ones are reversed.
This is a space-like metric.
In the Minkowski metric the space-like interval is defined as
We use the space-like Minkowski metric in the rest of this article.
The length of a |
https://en.wikipedia.org/wiki/Consistent%20Overhead%20Byte%20Stuffing | Consistent Overhead Byte Stuffing (COBS) is an algorithm for encoding data bytes that results in efficient, reliable, unambiguous packet framing regardless of packet content, thus making it easy for receiving applications to recover from malformed packets. It employs a particular byte value, typically zero, to serve as a packet delimiter (a special value that indicates the boundary between packets). When zero is used as a delimiter, the algorithm replaces each zero data byte with a non-zero value so that no zero data bytes will appear in the packet and thus be misinterpreted as packet boundaries.
Byte stuffing is a process that transforms a sequence of data bytes that may contain 'illegal' or 'reserved' values (such as packet delimiter) into a potentially longer sequence that contains no occurrences of those values. The extra length of the transformed sequence is typically referred to as the overhead of the algorithm. HDLC framing is a well-known example, used particularly in PPP (see RFC 1662 § 4.2). Although HDLC framing has an overhead of <1% in the average case, it suffers from a very poor worst-case overhead of 100%; for inputs that consist entirely of bytes that require escaping, HDLC byte stuffing will double the size of the input.
The COBS algorithm, on the other hand, tightly bounds the worst-case overhead. COBS requires a minimum of 1 byte overhead, and a maximum of bytes for n data bytes (one byte in 254, rounded up). Consequently, the time to transmit the encoded byte sequence is highly predictable, which makes COBS useful for real-time applications in which jitter may be problematic. The algorithm is computationally inexpensive, and in addition to its desirable worst-case overhead, its average overhead is also low compared to other unambiguous framing algorithms like HDLC.
COBS does, however, require up to 254 bytes of lookahead. Before transmitting its first byte, it needs to know the position of the first zero byte (if any) in the following 254 by |
https://en.wikipedia.org/wiki/Roberts%27s%20triangle%20theorem | Roberts's triangle theorem, a result in discrete geometry, states that every simple arrangement of lines has at least triangular faces. Thus, three lines form a triangle, four lines form at least two triangles, five lines form at least three triangles, etc. It is named after Samuel Roberts, a British mathematician who published it in 1889.
Statement and example
The theorem states that every simple arrangement of lines in the Euclidean plane has at least triangular faces. Here, an arrangement is simple when it has no two parallel lines and no three lines through the same point.
One way to form an arrangement of lines with exactly triangular faces is to choose the lines to be tangent to a semicircle. For lines arranged in this way, the only triangles are the ones formed by three lines with consecutive points of tangency. As the lines have consecutive triples, they also have triangles.
Proof
Branko Grünbaum found the proof in Roberts's original paper "unconvincing", and credits the first correct proof of Roberts's theorem to Robert W. Shannon, in 1979. He presents instead the following more elementary argument, first published in Russian by Alexei Belov. It depends implicitly on a simpler version of the same theorem, according to which every simple arrangement of three or more lines has at least one triangular face. This follows easily by induction from the fact that adding a line to an arrangement cannot decrease the number of triangular faces: if the line cuts an existing triangle, one of the resulting two pieces is again a triangle. On the other hand, although the bound of Roberts's theorem increases with each added line, the number of triangles in any particular arrangement may sometimes remain unchanged.
If the given lines are all moved without changing their slopes, their new positions can be described by a system of real numbers, the offsets of each line from its original position. For each triangular face, there is a linear equation on the offse |
https://en.wikipedia.org/wiki/Micha%20Sharir | Micha Sharir (; born 8 June 1950 in Tel Aviv, Israel) is an Israeli mathematician and computer scientist. He is a professor at Tel Aviv University, notable for his contributions to computational geometry and combinatorial geometry, having authored hundreds of papers.
Biography
Sharir was born in Tel Aviv in 1950. As a secondary school student he won the first place in the youth mathematics olympics of the Weizmann Institute of Science and Grossman Award from the Technion. In 1970, he completed his undergraduate studies and then served in unit 8200 of the Israel Defense Forces, during his service he was involved in a research team which won the 1975 Israel Defense Prize. In 1976, Sharir completed his doctoral (Ph.D.) studies in pure mathematics under the supervision of Aldo Lazar in Tel Aviv University. Then he began his postdoctoral studies at the Courant Institute of New York University, where he worked with Jack Schwartz.
In 1980, he joined the faculty of Tel Aviv University, where he holds the Isaias Nizri Chair in Computational Geometry and Robotics . He is also a visiting research professor at the Courant Institute, where he has been the deputy head of the Robotics Lab (1985–89). At Tel Aviv University, he has served as head of the computer science department (twice), head of the school of mathematics (1997–99), and is one of the cofounders of the Minerva Center for Geometry.
Sharir was named a Fellow of the Association for Computing Machinery in 1997. He received an honorary doctorate from Utrecht University in 1996, the Feher Foundation Prize in Computer Science from the Jerusalem Institute for Israel Studies in 1999, the Landau Prize for Science and Research in 2002, and the million-dollar The EMET Prize for Art, Science and Culture in the Exact Sciences from the A.M.N. Foundation in 2007.
Sharir is an Institute for Scientific Information, ISI Highly Cited researcher.
He was involved with developing international standards in programming and informatics |
https://en.wikipedia.org/wiki/Alcohol%20dehydrogenase | Alcohol dehydrogenases (ADH) () are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of nicotinamide adenine dinucleotide (NAD+) to NADH. In humans and many other animals, they serve to break down alcohols that are otherwise toxic, and they also participate in the generation of useful aldehyde, ketone, or alcohol groups during the biosynthesis of various metabolites. In yeast, plants, and many bacteria, some alcohol dehydrogenases catalyze the opposite reaction as part of fermentation to ensure a constant supply of NAD+.
Evolution
Genetic evidence from comparisons of multiple organisms showed that a glutathione-dependent formaldehyde dehydrogenase, identical to a class III alcohol dehydrogenase (ADH-3/ADH5), is presumed to be the ancestral enzyme for the entire ADH family. Early on in evolution, an effective method for eliminating both endogenous and exogenous formaldehyde was important and this capacity has conserved the ancestral ADH-3 through time. Gene duplication of ADH-3, followed by series of mutations, led to the evolution of other ADHs.
The ability to produce ethanol from sugar (which is the basis of how alcoholic beverages are made) is believed to have initially evolved in yeast. Though this feature is not adaptive from an energy point of view, by making alcohol in such high concentrations so that they would be toxic to other organisms, yeast cells could effectively eliminate their competition. Since rotting fruit can contain more than 4% of ethanol, animals eating the fruit needed a system to metabolize exogenous ethanol. This was thought to explain the conservation of ethanol active ADH in species other than yeast, though ADH-3 is now known to also have a major role in nitric oxide signaling.
In humans, sequencing of the ADH1B gene (responsible for production of an alcohol dehydrogenase polypeptide) shows several functional variants. In one, t |
https://en.wikipedia.org/wiki/Climber%27s%20finger | Climber's finger is one of the most common climbing injuries within the sport of rock climbing, accounting for about 30% of finger injuries seen in climbers. It is an overuse injury that usually manifests in a swollen middle or ring finger due to a damaged flexor tendon pulley, normally the A2 or A4 pulley. It is particularly common after a repeated utilization of small holds. Continued climbing on an injured finger may result in increased downtime in order to recover. The injury was first described in 1988 by Dr. S.R. Bollen.
Cause
Rock climbers often support their body with bent fingers on small edges, known as "crimps", especially on more difficult routes. This can cause a characteristic injury to the pulleys (annular ligaments), named "climber's finger".
Treatment
Management of pulley injuries of the fingers is to follow the RICE method. Other treatment suggestions are listed below:
The patient is to immediately cease climbing and any other activity that puts stress on the injured finger, and consult a doctor if there is noticeable "bowstringing" on the flexor tendon or if unsure about the nature of the injury.
There are different theories out there for the preferred line of approach. Some argue for the use of NSAIDs and ice for visible swelling only.
Light massage can be used to increase blood flow to the injured area, aiding recovery. Massage tools such as acupressure rings can be beneficial in the same way.
Protein supplements may help the tendons recover faster by providing much needed building block nutrients.
When the pain and swelling is gone (depending on the grade of the injury, 1–4 weeks), the patient can begin with an active healing process – containing squeezing putty clay or a stress ball. This can be combined with mild exercise, such as finger flexions, to ensure the finger will heal properly and better prepared for future stress. The use of heating pads and cold water baths are also mentioned in several sources in order to increase blood |
https://en.wikipedia.org/wiki/Reproductive%20assurance | Reproductive assurance (fertility assurance) occurs as plants have mechanisms to assure full seed set through selfing when outcross pollen is limiting. It is assumed that self-pollination is beneficial, in spite of potential fitness costs, when there is insufficient pollinator services or outcross pollen from other individuals to accomplish full seed set.. This phenomenon has been observed since the 19th century, when Darwin observed that self-pollination was common in some plants. Constant pollen limitation may cause the evolution of automatic selfing, also known as autogamy. This occurs in plants such as weeds, and is a form of reproductive assurance. As plants pursue reproductive assurance through self-fertilization, there is an increase in homozygosity , and inbreeding depression, due to genetic load, which results in reduced fitness of selfed offspring. Solely outcrossing plants may not be successful colonizers of new regions due to lack of other plants to outcross with, so colonizing species are expected to have mechanisms of reproductive assurance - an idea first proposed by Herbert G. Baker and referred to as Baker's "law" or "rule". Baker's law predicts that reproductive assurance affects establishment of plants in many contexts, including spread by weedy plants and following long-distance dispersal, such as occurs during island colonization. As plants evolve towards increase self-fertilization, energy is redirected to seed production rather than characteristics that increased outcrossing, such as floral attractants, which is a condition known as the selfing syndrome.
Evolution
Reproductive assurance is thought to be a driver for the evolution of selfing because it would promote purging of genetic load and it contributes to the occurrence of mixed mating systems. There are a number of mechanisms that result in reproductive assurance, but delayed selfing has been the one most studied. When pollination is unsuccessful, full seed set can be obtained through |
https://en.wikipedia.org/wiki/Anterior%20clinoid%20process | The anterior clinoid process is a bilaterally paired posterior projection of the sphenoid bone at the junction of the medial end of either lesser wing of sphenoid bone with the body of sphenoid bone. The two anterior clinoid processes flank the pituitary fossa anteriorly. The free border of the tentorium cerebelli attaches onto the anterior clinoid processes. A middle clinoid process is situated medial to each anterior clinoid process, with the internal carotid artery passing between the two (i.e. medial to the anterior clinoid process.)
Anatomy
Attachments
The free border of the tentorium cerebelli extends anteriorly on either side beyond the attached border of the same side (which ends anteriorly at the posterior clinoid process) to ultimately end by attaching onto the anterior clinoid process.
Etymology
The anterior and posterior clinoid processes surround the sella turcica like the four corners of a four poster bed. Cline is Greek for bed. –oid, as usual, indicates a similarity to. The term may also come from the Greek root klinein or the Latin clinare, both meaning "sloped" as in "inclined".
Additional images |
https://en.wikipedia.org/wiki/NHS%20East%20of%20England | NHS East of England was a strategic health authority of the National Health Service in England. It operated in the East of England region, which is coterminous with the local government office region. The authority closed on 31 March 2013 as part of the Health and Social Care Act 2012.
External links
Official website
East of England
2013 disestablishments in England |
https://en.wikipedia.org/wiki/Stability%20of%20the%20Solar%20System | The stability of the Solar System is a subject of much inquiry in astronomy. Though the planets have been stable when historically observed, and will be in the short term, their weak gravitational effects on one another can add up in unpredictable ways.
For this reason (among others), the Solar System is chaotic in the technical sense of mathematical chaos theory, and even the most precise long-term models for the orbital motion of the Solar System are not valid over more than a few tens of millions of years.
The Solar System is stable in human terms, and far beyond, given that it is unlikely any of the planets will collide with each other or be ejected from the system in the next few billion years, and that Earth's orbit will be relatively stable.
Since Newton's law of gravitation (1687), mathematicians and astronomers (such as Pierre-Simon Laplace, Joseph Louis Lagrange, Carl Friedrich Gauss, Henri Poincaré, Andrey Kolmogorov, Vladimir Arnold, and Jürgen Moser) have searched for evidence for the stability of the planetary motions, and this quest led to many mathematical developments and several successive "proofs" of stability of the Solar System.
Overview and challenges
The orbits of the planets are open to long-term variations. Modeling the Solar System is a case of the n-body problem of physics, which is generally unsolvable except by numerical simulation.
Resonance
An orbital resonance happens when any two periods have a simple numerical ratio. The most fundamental period for an object in the Solar System is its orbital period, and orbital resonances pervade the Solar System. In 1867, the American astronomer Daniel Kirkwood noticed that asteroids in the asteroid belt are not randomly distributed. There were distinct gaps in the belt at locations that corresponded to resonances with Jupiter. For example, there were no asteroids at the 3:1 resonance — a distance of — or at the 2:1 resonance at . These are now known as the Kirkwood gaps. Some asteroids |
https://en.wikipedia.org/wiki/Distinction%20bias | Distinction bias, a concept of decision theory, is the tendency to view two options as more distinctive when evaluating them simultaneously than when evaluating them separately.
One writer has presented what he called "a simplistic view" of distinction bias: When asked if someone would like an apple, they may say "Yes". So, an apple is placed before them and they begin to eat it and are happy. But what if two apples were placed on the table - one was the one they would have happily eaten and the other which is slightly fresher looking. The individual will choose the fresher apple and eat it and be happy but if asked, "would you have enjoyed eating that other apple", they would likely say "No". Even though in the alternate, no-choice reality they were perfectly happy with the apple. Moreover, if presented with five apples on a table, they might examine each apple so that they would be sure they had the best one, even though the time spent making that decision would be wasted. The reason for this is that distinction bias causes individuals to "over-examine and over-value the differences between things as we scrutinize them."
Hsee and Zhang
The concept of the distinction bias was advanced by Christopher K. Hsee and Jiao Zhang of the University of Chicago as an explanation for differences in evaluations of options between joint evaluation mode and separate evaluation mode (2004). Evaluation mode is a contextual feature in decision making. Joint evaluation mode is when options are evaluated simultaneously, and separate evaluation mode is when each option is evaluated in isolation (e.g., Hsee, 1998; Hsee & Leclerc, 1998). Research shows that evaluation mode affects the evaluation of options, such that options presented simultaneously are evaluated differently from the same options presented separately.
Hsee and Zhang (2004) offered a number of potential explanations for this change in preferences from joint evaluation to separate evaluation, including the distinction |
https://en.wikipedia.org/wiki/Action%20axiom | An action axiom is an axiom that embodies a criterion for describing action. Action axioms are of the form "If a condition holds, then the following will be done".
On the action axiom
Decision theory and, hence, decision analysis are based on the maximum expected utility (MEU) action axiom. In general, the principle for action embodied by an action axiom (such as MEU) is highly defensible and its scope very broad.
The action-axiom is the basis of praxeology in the Austrian School, and it is the proposition that all specimens of the species Homo sapiens, the Homo agens, purposely utilize means over a period of time in order to achieve desired ends. In Human Action, Ludwig von Mises defined “action” in the sense of the action axiom by elucidating:
See also
Norm (artificial intelligence)
Notes
Expected utility |
https://en.wikipedia.org/wiki/Mathematics%20of%20apportionment | Mathematics of apportionment describes mathematical principles and algorithms for fair allocation of identical items among parties with different entitlements. Such principles are used to apportion seats in parliaments among federal states or political parties. See apportionment (politics) for the more concrete principles and issues related to apportionment, and apportionment by country for practical methods used around the world.
Mathematically, an apportionment method is just a method of rounding fractions to integers. As simple as it may sound, each and every method for rounding suffers from one or more paradoxes. The mathematical theory of apportionment aims to decide what paradoxes can be avoided, or in other words, what properties can be expected from an apportionment method.
The mathematical theory of apportionment was studied as early as 1907 by the mathematician Agner Krarup Erlang. It was later developed to a great detail by the mathematician Michel Balinsky and the economist Peyton Young. Besides its application to political parties, it is also applicable to fair item allocation when agents have different entitlements. It is also relevant in manpower planning - where jobs should be allocated in proportion to characteristics of the labor pool, to statistics - where the reported rounded numbers of percentages should sum up to 100%, and to bankruptcy problems.
Definitions
Input
The inputs to an apportionment method are:
A positive integer representing the total number of items to allocate. It is also called the house size, since in many cases, the items to allocate are seats in a house of representatives.
A positive integer representing the number of agents to which items should be allocated. For example, these can be federal states or political parties.
A vector of numbers representing entitlements - represents the entitlement of agent , that is, the amount of items to which is entitled (out of the total of ). These entitlements are often norma |
https://en.wikipedia.org/wiki/Aluminum%20Model%20Toys | Aluminum Model Toys (AMT) is a toy manufacturing brand founded in Troy, Michigan, in 1948 by West Gallogly Sr. AMT became known for manufacturing 1/25 scale plastic automobile dealer promotional model cars and friction motor models, and pioneered the annual 3-in-1 model kit buildable in stock, custom, or hot-rod versions. The company made a two-way deal in 1966 with Desilu Productions to produce a line of Star Trek models and to produce a 3/4 scale exterior and interior filming set of the Galileo shuttlecraft. It was also known for producing model trucks and movie and TV vehicles.
The AMT brand was bought in 1978 by the Lesney company of UK, then by competitor Ertl in 1983, then by the Round 2 company in 2012.
History
Beginning
Because Gallogly had solid connections with Ford Motor Company, he was able to place his first models exclusively in Ford dealerships, starting a long promotional relationship. Gallogly's first model was a 1947–1948 Ford Fordor sedan made of cast aluminum and painted with official Ford paint. After issuing successful Ford sedan models, the company set up shop on Eight Mile Road outside Detroit.
By 1948, injection plastic molding was already being used by Product Miniature Corporation (PMC). After the first Ford aluminum promotional model was offered, aluminum was abandoned. Different colors of plastic could now be used, so the company name was quietly changed to AMT, which deemphasized the word "aluminum". For example, AMT's 1949 and 1950 Ford and Plymouth sedans were its first plastic models, along with the 1950 Studebaker coupe. These promos often had wind-up motors which could not be seen through the shiny silver-tinted windows. They had metal chassis and diecast metal chrome-plated bumpers, which were later replaced with chrome-plated plastic. Often, official factory paint colors were applied to the models. The company's first commercial products were pre-assembled plastic promotional models, which were only available through automob |
https://en.wikipedia.org/wiki/Vehicle-to-device | Vehicle-to-device (V2D) communication is a particular type of vehicular communication system that consists in the exchange of information between a vehicle and any electronic device that may be connected to the vehicle itself.
The ever-increasing tendency of developing mobile applications for our everyday use has ultimately entered also the automotive sector. Vehicle connectivity with mobile apps have the great potential to offer a better driving experience, by providing information regarding the surrounding vehicles and infrastructure and making the interaction between the car and its driver much simpler. The fact that apps may significantly improve driving safety has attracted the attention of car users and caused a rise in the number of new apps developed specifically for the car industry. This trend has such a great influence that now manufacturers are beginning to design cars taking care of their interaction with mobile phones. For example, starting from 2017 Volvo is going to sell keyless cars, thanks to an app that makes it possible to open and start the vehicle remotely.
Another sector that could coherently benefit from this technology is car sharing.
See also
Vehicular communication systems
Vehicle-to-everything (V2X)
Vehicular ad hoc network (V2V)
Vehicle-to-grid (V2G)
Vehicle-to-vehicle (V2V) |
https://en.wikipedia.org/wiki/Human%20genome | The human genome is a complete set of nucleic acid sequences for humans, encoded as DNA within the 23 chromosome pairs in cell nuclei and in a small DNA molecule found within individual mitochondria. These are usually treated separately as the nuclear genome and the mitochondrial genome. Human genomes include both protein-coding DNA sequences and various types of DNA that does not encode proteins. The latter is a diverse category that includes DNA coding for non-translated RNA, such as that for ribosomal RNA, transfer RNA, ribozymes, small nuclear RNAs, and several types of regulatory RNAs. It also includes promoters and their associated gene-regulatory elements, DNA playing structural and replicatory roles, such as scaffolding regions, telomeres, centromeres, and origins of replication, plus large numbers of transposable elements, inserted viral DNA, non-functional pseudogenes and simple, highly repetitive sequences. Introns make up a large percentage of non-coding DNA. Some of this non-coding DNA is non-functional junk DNA, such as pseudogenes, but there is no firm consensus on the total amount of junk DNA.
Haploid human genomes, which are contained in germ cells (the egg and sperm gamete cells created in the meiosis phase of sexual reproduction before fertilization) consist of 3,054,815,472 DNA base pairs (if X chromosome is used), while female diploid genomes (found in somatic cells) have twice the DNA content.
While there are significant differences among the genomes of human individuals (on the order of 0.1% due to single-nucleotide variants and 0.6% when considering indels), these are considerably smaller than the differences between humans and their closest living relatives, the bonobos and chimpanzees (~1.1% fixed single-nucleotide variants and 4% when including indels). Size in basepairs can vary too; the telomere length decreases after every round of DNA replication.
Although the sequence of the human genome has been completely determined by DNA sequen |
https://en.wikipedia.org/wiki/Achroonema | Achroonema is a genus of bacteria with uncertain systematics.
The genus was described in 1948 by Heinrich Leonhards Skuja.
Species:
Achroonema angustatum (Koppe) Skuja
Achroonema articulatum Skuja
Achroonema gotlandicum Skuja
Achroonema inaequale Skuja
Achroonema lentum Skuja
Achroonema macromeres Skuja
Achroonema proteiforme Skuja
Achroonema simplex Skuja
Achroonema spiroideum Skuja
Achroonema splendens Skuja
Achroonema sporogenum Skuja
Achroonema subsalsum Behre |
https://en.wikipedia.org/wiki/Coronal%20radiative%20losses | In astronomy and in astrophysics, for radiative losses of the solar corona, it is meant the energy flux radiated from the external atmosphere of the Sun (traditionally divided into chromosphere, transition region and corona), and, in particular, the processes of production of the radiation coming from the solar corona and transition region, where the plasma is optically-thin. On the contrary, in the chromosphere, where the temperature decreases from the photospheric value of 6000 K to the minimum of 4400 K, the optical depth is about 1, and the radiation is thermal.
The corona extends much further than a solar radius from the photosphere and looks very complex and inhomogeneous in the X-rays images taken by satellites (see the figure on the right taken by the XRT on board Hinode).
The structure and dynamics of the corona are dominated by the solar magnetic field. There are strong evidences that even the heating mechanism, responsible for its high temperature of million degrees, is linked to the magnetic field of the Sun.
The energy flux irradiated from the corona changes in active regions, in the quiet Sun and in coronal holes; actually, part of the energy is irradiated outwards, but approximately the same amount of the energy flux is conducted back towards the chromosphere, through the steep transition region. In active regions the energy flux is about 107 erg cm−2sec−1, in the quiet Sun it is roughly 8 105 – 106 erg cm−2sec−1, and in coronal holes 5 105 - 8 105 erg cm−2sec−1, including the losses due to the solar wind.
The required power is a small fraction of the total flux irradiated from the Sun, but this energy is enough to maintain the plasma at the temperature of million degrees, since the density is very low and the processes of radiation are different from those occurring in the photosphere, as it is shown in detail in the next section.
Processes of radiation of the solar corona
The electromagnetic waves coming from the solar corona are emitted mai |
https://en.wikipedia.org/wiki/Baruch%20Barzel | Baruch Barzel (March 19, 1976) is an Israeli physicist and applied mathematician at Bar-Ilan University,
a member of the Gonda Multidisciplinary Brain Research Center and of the Bar-Ilan Data Science Institute. His main research areas are statistical physics, complex systems, nonlinear dynamics and network science.
In 2013 he introduced the concept of universality in the dynamics of complex networks, showing that complex systems from different domains condense into discrete forms, or universality classes, of dynamic behavior. In the following years, Barzel and colleagues developed a theoretical framework to predict the observed behavior of complex networked systems: their patterns of information flow; the timescales of their signal propagation; their resilience against failures and disruptions and their recoverability.
During the COVID-19 Pandemic Barzel's lab published the alternating quarantine strategy to mitigate the spread of SARS-CoV-2 alongside continuous socioeconomic activity. The strategy was implemented by several agencies in Israel and around the world.
Academic career
Barzel completed his Ph.D. in physics at the Hebrew University of Jerusalem, Israel
as a Hoffman Fellow.
He then pursued his postdoctoral training at the Center for Complex Network Research at Northeastern University
and at the Channing Division of Network Medicine, Harvard Medical School. Barzel is a recipient of the Racah prize (2007) and the Krill prize of the Wolf Foundation (2019). Barzel is also an active public lecturer on science and on Judaism, and presents a weekly corner on Jewish thought on Israeli Public Broadcasting Corporation
.
Dr. Barzel's research focuses on the dynamic behavior of complex networks, uncovering universal principles that govern the dynamics of diverse systems, such as disease spreading, gene regulatory networks, protein interactions or population dynamics.
Selected publications
J. Gao, B. Barzel and A.-L. Barabási, "Universal resilience patterns in |
https://en.wikipedia.org/wiki/Luhn%20algorithm | The Luhn algorithm or Luhn formula, also known as the "modulus 10" or "mod 10" algorithm, named after its creator, IBM scientist Hans Peter Luhn, is a simple check digit formula used to validate a variety of identification numbers.
It is described in U.S. Patent No. 2,950,048, granted on August 23, 1960.
The algorithm is in the public domain and is in wide use today. It is specified in ISO/IEC 7812-1. It is not intended to be a cryptographically secure hash function; it was designed to protect against accidental errors, not malicious attacks. Most credit cards and many government identification numbers use the algorithm as a simple method of distinguishing valid numbers from mistyped or otherwise incorrect numbers.
Description
The check digit is computed as follows:
If the number already contains the check digit, drop that digit to form the "payload". The check digit is most often the last digit.
With the payload, start from the rightmost digit. Moving left, double the value of every second digit (including the rightmost digit).
Sum the values of the resulting digits.
The check digit is calculated by , where s is the sum from step 3. This is the smallest number (possibly zero) that must be added to to make a multiple of 10. Other valid formulas giving the same value are , , and . Note that the formula will not work in all environments due to differences in how negative numbers are handled by the modulo operation.
Example for computing check digit
Assume an example of an account number 1789372997 (just the "payload", check digit not yet included):
The sum of the resulting digits is 56.
The check digit is equal to .
This makes the full account number read 17893729974.
Example for validating check digit
Drop the check digit (last digit) of the number to validate. (e.g. 17893729974 → 1789372997)
Calculate the check digit (see above)
Compare your result with the original check digit. If both numbers match, the result is valid.
Strengths and weakne |
https://en.wikipedia.org/wiki/Quantum%20Theory%3A%20Concepts%20and%20Methods | Quantum Theory: Concepts and Methods is a 1993 quantum physics textbook by Israeli physicist Asher Peres. Well-regarded among the physics community, it is known for unconventional choices of topics to include.
Contents
In his preface, Peres summarized his goals as follows:
The purpose of this book is to clarify the conceptual meaning of quantum theory, and to explain some of the mathematical methods that it utilizes. This text is not concerned with specialized topics such as atomic structure, or strong or weak interactions, but with the very foundations of the theory. This is not, however, a book on the philosophy of science. The approach is pragmatic and strictly instrumentalist. This attitude will undoubtedly antagonize some readers, but it has its own logic: quantum phenomena do not occur in a Hilbert space, they occur in a laboratory.
The book is divided into three parts. The first, "Gathering the Tools", introduces quantum mechanics as a theory of "preparations" and "tests", and it develops the mathematical formalism of Hilbert spaces, concluding with the spectral theory used to understand the quantum mechanics of continuous-valued observables. Part II, "Cryptodeterminism and Quantum Inseparability", focuses on Bell's theorem and other demonstrations that quantum mechanics is incompatible with local hidden-variable theories. (Within its substantial discussion of the failure of hidden variable theories, the book includes a FORTRAN program for testing whether a list of vectors forms a Kochen–Specker configuration.) Part III, "Quantum Dynamics and Information", covers the role of spacetime symmetry in quantum physics, the relation of quantum information to thermodynamics, semiclassical approximation methods, quantum chaos, and the treatment of measurement in quantum mechanics.
To generate the figures in his chapter on quantum chaos, including plots in phase space of chaotic motion, Peres wrote PostScript code that executed simulations in the printer itself.
T |
https://en.wikipedia.org/wiki/Atomic%20Bomb%20Casualty%20Commission | The Atomic Bomb Casualty Commission (ABCC) (Japanese:原爆傷害調査委員会, Genbakushōgaichōsaiinkai) was a commission established in 1946 in accordance with a presidential directive from Harry S. Truman to the National Academy of Sciences-National Research Council to conduct investigations of the late effects of radiation among the atomic-bomb survivors in Hiroshima and Nagasaki. As it was erected purely for scientific research and study, not as a provider of medical care and also because it was heavily supported by the United States, the ABCC was generally mistrusted by most survivors and Japanese alike. It operated for nearly thirty years before its dissolution in 1975.
History
The Atomic Bomb Casualty Commission (ABCC) was formed after the United States attack on Hiroshima and Nagasaki on August 6 and August 9, 1945. The ABCC originally began as the Joint Commission The ABCC set out to obtain first-hand technical information and make a report to let people know the opportunities for a long-term study of atomic bomb casualties. In 1946, Lewis Weed, head of the National Research Council, called together a group of scientists who agreed that a "detailed and long-range study of the biological and medical effects upon the human being" was "of the utmost importance to the United States and mankind in general." President Harry S. Truman ordered the ABCC into existence on November 26, 1946. The key members in the ABCC were Lewis Weed, National Research Council physicians Austin M. Brues and Paul Henshaw, and Army representatives Melvin A. Block, and James V. Neel who was also an MD with a Ph.D. in genetics.
The fifth person on the team was USNV Ltd. Jg Fredrick Ullrich of Naval Medical Research Center appointed by the National Research Council at the suggestion of the Surgeon General's Office.
The Atomic Bomb Casualty Commission's Work
The ABCC arrived in Japan on November 24, 1946, and familiarized themselves with the procedures of the Japanese military. They visited Hiroshi |
https://en.wikipedia.org/wiki/Biochemistry | Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology, and metabolism. Over the last decades of the 20th century, biochemistry has become successful at explaining living processes through these three disciplines. Almost all areas of the life sciences are being uncovered and developed through biochemical methodology and research. Biochemistry focuses on understanding the chemical basis which allows biological molecules to give rise to the processes that occur within living cells and between cells, in turn relating greatly to the understanding of tissues and organs, as well as organism structure and function. Biochemistry is closely related to molecular biology, which is the study of the molecular mechanisms of biological phenomena.
Much of biochemistry deals with the structures, bonding, functions, and interactions of biological macromolecules, such as proteins, nucleic acids, carbohydrates, and lipids. They provide the structure of cells and perform many of the functions associated with life. The chemistry of the cell also depends upon the reactions of small molecules and ions. These can be inorganic (for example, water and metal ions) or organic (for example, the amino acids, which are used to synthesize proteins). The mechanisms used by cells to harness energy from their environment via chemical reactions are known as metabolism. The findings of biochemistry are applied primarily in medicine, nutrition and agriculture. In medicine, biochemists investigate the causes and cures of diseases. Nutrition studies how to maintain health and wellness and also the effects of nutritional deficiencies. In agriculture, biochemists investigate soil and fertilizers, with the goal of improving crop cultivation, crop storage, and pest control. In recent decades, biochemical principles a |
https://en.wikipedia.org/wiki/Time-delay%20combination%20locks | A time-delay combination lock is most commonly a digital, electronic combination lock equipped with a delay timer that delays the unlocking of the lock by a user-definable delay period, usually less than one hour. Unlike the time lock, which unlocks at a preset time (as in the case of a bank vault), time-delay locks operate each time the safe is unlocked, but the operator must wait for the set delay period to elapse before the lock can be opened. Time delay safes are most commonly used in businesses with high cash transactions. They are used in some banks including Nationwide, HSBC, Barclays, and Halifax.
Use
Time-delay combination locks are frequently incorporated into money safes as an armed robbery deterrent. In many instances, time-delay combination locks are also equipped with a duress code which may be entered to activate the time delay whilst sending a silent alarm to a monitoring centre.
Modern time delay combination locks can have many functions such as multiple different codes, pre-set time lock settings (open and close times), pre-set vacation times (e.g. Christmas Day), dual code facility, and a full audit trail providing a detailed record of the lock history showing who opened the lock, when and how long it was open.
They also use a non-volatile memory so that no information is lost if the batteries are depleted. This will allow the safe to be opened when the batteries are changed after the pre-set time if the correct code is entered. Some electronic combination locks with a time-delay feature require the code to be entered twice: once to start the timer, and a second to unlock and open the safe entered after the delay period has expired. |
https://en.wikipedia.org/wiki/C.C.%20Lang%20%26%20Son | C. C. Lang & Son was a Baltimore-based pickle and sauerkraut manufacturing company that was founded in 1881. Located in one of the chief canning cities of the United States, the pickle and sauerkraut company supplied their own cucumbers and cabbage from the Lang Farm, located in Glen Arm, Maryland.
Started by German immigrant C.C. Lang, the business was passed down to Charles Gottlieb Lang, (1890–1956) who expanded the small business into an enterprise employing 700 persons in Maryland, Virginia, South Carolina, North Carolina, New York, Wisconsin, and Michigan.
In the 1940s this pickle and sauerkraut industry was made up of about 300 canning factories located around the country. In addition to C.C. Lang & Son, these companies include the H. J. Heinz Company and Hunt Foods, as well as California Packing Corp, Green Bay Food Company and Libby, McNeill & Libby. |
https://en.wikipedia.org/wiki/Adiantum%20%28cipher%29 | Adiantum is a cipher construction for disk encryption, which uses the ChaCha and Advanced Encryption Standard (AES) ciphers, and Poly1305 cryptographic message authentication code (MAC).
It was designed in 2018 by Paul Crowley and Eric Biggers at Google specifically for low-powered mobile devices running Android Go. It has been included in the Linux kernel since version 5.0.
HPolyC is an earlier variant of Adiantum, which uses a different construction for the Poly1305 hash function.
Adiantum is implemented in Android 10 as an alternative cipher for device encryption, particularly on low-end devices lacking hardware-accelerated support for AES. The company stated that Adiantum ran five times faster than AES-256-XTS on ARM Cortex-A7 CPUs. Google had previously exempted devices from mandatory device encryption if their specifications affected system performance if enabled. Due to the introduction of Adiantum, device encryption becomes mandatory on all Android devices beginning on Android 10. |
https://en.wikipedia.org/wiki/Computable%20real%20function | In mathematical logic, specifically computability theory, a function is sequentially computable if, for every computable sequence of real numbers, the sequence is also computable.
A function is effectively uniformly continuous if there exists a recursive function such that, if
then
A real function is computable if it is both sequentially computable and effectively uniformly continuous,
These definitions can be generalized to functions of more than one variable or functions only defined on a subset of The generalizations of the latter two need not be restated. A suitable generalization of the first definition is:
Let be a subset of A function is sequentially computable if, for every -tuplet of computable sequences of real numbers such that
the sequence is also computable. |
https://en.wikipedia.org/wiki/Computability%20in%20Europe | The Association Computability in Europe (ACiE) is an international organization of mathematicians, logicians, computer scientists, philosophers, theoretical physicists and others interested in new developments in computability and in their underlying significance for the real world. CiE aims to widen understanding and appreciation of the importance of the concepts and techniques of computability theory, and to support the development of a vibrant multi-disciplinary community of researchers focused on computability-related topics. The ACiE positions itself at the interface between applied and fundamental research, prioritising mathematical approaches to computational barriers.
The Association Computability in Europe originated as a research network called Computability in Europe (CiE) in 2003, became a conference series in 2005, and the ACiE was formed in 2008.
Association
The Association Computability in Europe was founded in Athens, Greece in 2008. Its founding president (2008 to 2015) was Professor S. Barry Cooper; its current president is Elvira Mayordomo and its current secretary general is Giuseppe Primiero.
The Association is promoting the development, particularly in Europe, of computability-related science, ranging over mathematics, computer science, and applications in various natural and engineering sciences such as physics and biology. This also includes the promotion of the study of philosophy and history of computing as it relates to questions of computability. The ACiE is an international member of the Division for Logic, Methodology and Philosophy of Science and Technology of the International Union of History and Philosophy of Science (DLMPST/IUHPST).
Past and Present Presidents
Current Members of the Association Council
The current member of the Council of the Association are
Marcella Anselmo,
Arnold Beckmann,
Paola Bonizzoni (Past President),
Olivier Bournez,
Merlin Carl,
Liesbeth De Mol (Member-at-Large Executive Committee),
Gianluca Dell |
https://en.wikipedia.org/wiki/Wilfrid%20Hodges | Wilfrid Augustine Hodges, FBA (born 27 May 1941) is a British mathematician and logician known for his work in model theory.
Life
Hodges attended New College, Oxford (1959–65), where he received degrees in both Literae Humaniores and (Christianic) Theology. In 1970 he was awarded a doctorate for a thesis in Logic. He lectured in both Philosophy and Mathematics at Bedford College, University of London. He has held visiting appointments in the department of philosophy at the University of California and in the department of mathematics at University of Colorado. Hodges was Professor of Mathematics at Queen Mary College, University of London from 1987 to 2006 and is the author of books on logic.
Honors and awards
Hodges was President of the British Logic Colloquium, of the European Association for Logic, Language and Information and of the Division of Logic, Methodology, and Philosophy of Science. In 2009 he was elected a Fellow of the British Academy.
Writing style
Hodges' books are written in an informal style. The "Notes on Notation" in his book "Model theory" end with the following characteristic sentence:
'I' means I, 'we' means we.
When this 780-page book appeared in 1993, it became one of the standard textbooks on model theory. Due to its success an abbreviated version (but with a new chapter on stability theory) was published as a paperback.
Bibliography
Only first editions are listed. |
https://en.wikipedia.org/wiki/GDPR%20fines%20and%20notices | The General Data Protection Regulation (GDPR) is a European Union regulation that specifies standards for data protection and electronic privacy in the European Economic Area, and the rights of European citizens to control the processing and distribution of personally-identifiable information.
Violators of GDPR may be fined up to €20 million, or up to 4% of the annual worldwide turnover of the preceding financial year, whichever is greater. The following is a list of fines and notices issued under the GDPR, including reasoning.
Fines and notices |
https://en.wikipedia.org/wiki/Membrane%20computing | Membrane computing (or MC) is an area within computer science that seeks to discover new computational models from the study of biological cells, particularly of the cellular membranes. It is a sub-task of creating a cellular model.
Membrane computing deals with distributed and parallel computing models, processing multisets of symbol objects in a localized manner. Thus, evolution rules allow for evolving objects to be encapsulated into compartments defined by membranes. The communications between compartments and with the environment play an essential role in the processes. The various types of membrane systems are known as P systems after Gheorghe Păun who first conceived the model in 1998.
An essential ingredient of a P system is its membrane structure, which can be a hierarchical arrangement of membranes, as in a cell, or a net of membranes (placed in the nodes of a graph), as in a tissue or a neural net. P systems are often depicted graphically with drawings.
The intuition behind the notion of a membrane is a three-dimensional vesicle from biology. However the concept itself is more general, and a membrane is seen as a separator of two regions. The membrane provides for selective communication between the two regions. As per Gheorghe Păun, the separation is of the Euclidean space into a finite “inside” and an infinite “outside”. The selective communication is where the computing comes in.
Graphical representations may have numerous elements, according to the variation of the model that is being studied. For example, a rule may produce the special symbol δ, in which case the membrane that contains it is dissolved and all its contents move up in the region hierarchy.
The variety of suggestions from biology and the range of possibilities to define the architecture and the functioning of a membrane-based multiset processing device are practically endless. Indeed, the membrane computing literature contains a very large number of models. Thus, MC is not mer |
https://en.wikipedia.org/wiki/Envy-freeness | Envy-freeness, also known as no-envy, is a criterion for fair division. It says that, when resources are allocated among people with equal rights, each person should receive a share that is, in their eyes, at least as good as the share received by any other agent. In other words, no person should feel envy.
General definitions
Suppose a certain resource is divided among several agents, such that every agent receives a share . Every agent has a personal preference relation over different possible shares. The division is called envy-free (EF) if for all and :
Another term for envy-freeness is no-envy (NE).
If the preference of the agents are represented by a value functions , then this definition is equivalent to:
Put another way: we say that agent envies agent if prefers the piece of over his own piece, i.e.:
A division is called envy-free if no agent envies another agent.
Special cases
The notion of envy-freeness was introduced by George Gamow and Marvin Stern in 1958. They asked whether it is always possible to divide a cake (a heterogeneous resource) among n children with different tastes, such that no child envies another one. For n=2 children this can be done by the Divide and choose algorithm, but for n>2 the problem is much harder. See envy-free cake-cutting.
In cake-cutting, EF means that each child believes that their share is at least as large as any other share; in the chore division, EF means that each agent believes their share is at least as small as any other share (the crucial issue in both cases is that no agent would wish to swap their share with any other agent). See chore division.
Envy-freeness was introduced to the economics problem of resource allocation by Duncan Foley in 1967. In this problem, rather than a single heterogeneous resource, there are several homogeneous resources. Envy-freeness by its own is easy to attain by just giving each person 1/n of each resource. The challenge, from an economic perspective, is to combin |
https://en.wikipedia.org/wiki/Nasan | The Nasan Clustered File System is a shared disk file system created by the company DataPlow. Nasan software enables high-speed access to shared files located on shared, storage area network (SAN)-attached storage devices by utilizing the high-performance, scalable data transfers inherent to storage area networks and the manageability of network attached storage (NAS).
Nasan derives its name from the combination of network attached storage (NAS) and storage area network (SAN). Nasan clustered file sharing is an extension of traditional LAN file sharing yet utilizes storage area networks for data transfers. Deploying a Nasan cluster entails configuring LAN file sharing, installing Nasan file system software, and connecting computers and storage devices to the SAN.
Platforms
Supports Linux and Solaris operating systems.
Supports all SAN-based, block-level storage protocols including Fibre Channel and iSCSI. |
https://en.wikipedia.org/wiki/McIlvaine%20buffer | McIlvaine buffer is a buffer solution composed of citric acid and disodium hydrogen phosphate, also known as citrate-phosphate buffer. It was introduced in 1921 by the United States agronomist Theodore Clinton McIlvaine (1875–1959) from West Virginia University, and it can be prepared in pH 2.2 to 8 by mixing two stock solutions.
Applications
McIlvaine buffer can be used to prepare a water-soluble mounting medium when mixed 1:1 with glycerol.
Contents
Preparation of McIlvaine buffer requires disodium phosphate and citric acid. One liter of 0.2M stock solution of disodium hydroxyphosphate can be prepared by dissolving 28.38g of disodium phosphate in water, and adding a quantity of water sufficient to make one liter. One liter of 0.1M stock solution of citric acid can be prepared by dissolving 19.21g of citric acid in water, and adding a quantity of water sufficient to make one liter. From these stock solutions, McIlvaine buffer can be prepared in accordance with the following table: |
https://en.wikipedia.org/wiki/Biodesulfurization | Biodesulfurization is the process of removing sulfur from crude oil through the use of microorganisms or their enzymes.
Background
Crude oil contains sulfur in its composition, with the latter being the most abundant element after carbon and hydrogen. Depending on its source, the amount of sulfur present in crude oil can range from 0.05 to 10%. Accordingly, the oil can be classified as sweet or sour if the sulfur concentration is below or above 0.5%, respectively.
The combustion of crude oil releases sulfur oxides (SOx) to the atmosphere, which are harmful to public health and contribute to serious environmental effects such as air pollution and acid rains. In addition, the sulfur content in crude oil is a major problem for refineries, as it promotes the corrosion of the equipment and the poisoning of the noble metal catalysts. The levels of sulfur in any oil field are too high for the fossil fuels derived from it (such as gasoline, diesel, or jet fuel ) to be used in combustion engines without pre-treatment to remove organosulfur compounds.
The reduction of the concentration of sulfur in crude oil becomes necessary to mitigate one of the leading sources of the harmful health and environmental effects caused by its combustion. In this sense, the European union has taken steps to decrease the sulfur content in diesel below 10 ppm, while the US has made efforts to restrict the sulfur content in diesel and gasoline to a maximum of 15 ppm. The reduction of sulfur compounds in oil fuels can be achieved by a process named desulfurization. Methods used for desulfurization include, among others, hydrodesulfurization, oxidative desulfurization, extractive desulfurization, and extraction by ionic liquids.
Despite their efficiency at reducing sulfur content, the conventional desulfurization methods are still accountable for a significant amount of the CO2 emissions associated with the crude oil refining process, releasing up to 9000 metric tons per year. Furthermore, the |
https://en.wikipedia.org/wiki/Glaucophyte | The glaucophytes, also known as glaucocystophytes or glaucocystids, are a small group of unicellular algae found in freshwater and moist terrestrial environments, less common today than they were during the Proterozoic. The stated number of species in the group varies from about 14 to 26. Together with the red algae (Rhodophyta) and the green algae plus land plants (Viridiplantae or Chloroplastida), they form the Archaeplastida.
The glaucophytes are of interest to biologists studying the evolution of chloroplasts as they may be similar to the original algal type that led to the red algae and green plants, i.e. glaucophytes may be basal Archaeplastida.
Unlike red and green algae, glaucophytes only have asexual reproduction.
Characteristics
The plastids of glaucophytes are known as 'muroplasts', 'cyanoplasts', or 'cyanelles'. Unlike the plastids in other organisms, they have a peptidoglycan layer, believed to be a relic of the endosymbiotic origin of plastids from cyanobacteria. Glaucophytes contain the photosynthetic pigment chlorophyll a. Along with red algae and cyanobacteria, they harvest light via phycobilisomes, structures consisting largely of phycobiliproteins. The green algae and land plants have lost that pigment. Like red algae, and in contrast to green algae and plants, glaucophytes store fixed carbon in the cytosol.
The most early-diverging genus is Cyanophora, which only has one or two plastids. When there are two, they are semi-connected.
Glaucophytes have mitochondria with flat cristae, and undergo open mitosis without centrioles. Motile forms have two unequal flagella, which may have fine hairs and are anchored by a multilayered system of microtubules, both of which are similar to forms found in some green algae.
Phylogeny
External
Together with red algae and Viridiplantae (green algae and land plants), glaucophytes form the Archaeplastida – a group of plastid-containing organisms that may share a unique common ancestor that established a |
https://en.wikipedia.org/wiki/Mobile%20content%20management%20system | A mobile content management system (MCMs) is a type of content management system (CMS) capable of storing and delivering content and services to mobile devices, such as mobile phones, smart phones, and PDAs. Mobile content management systems may be discrete systems, or may exist as features, modules or add-ons of larger content management systems capable of multi-channel content delivery. Mobile content delivery has unique, specific constraints including widely variable device capacities, small screen size, limitations on wireless bandwidth, sometimes small storage capacity, and (for some devices) comparatively weak device processors.
Demand for mobile content management increased as mobile devices became increasingly ubiquitous and sophisticated. MCMS technology initially focused on the business to consumer (B2C) mobile market place with ringtones, games, text-messaging, news, and other related content. Since, mobile content management systems have also taken root in business-to-business (B2B) and business-to-employee (B2E) situations, allowing companies to provide more timely information and functionality to business partners and mobile workforces in an increasingly efficient manner. A 2008 estimate put global revenue for mobile content management at US$8 billion.
Key features
Multi-channel content delivery
Multi-channel content delivery capabilities allow users not to manage a central content repository while simultaneously delivering that content to mobile devices such as mobile phones, smartphones, tablets and other mobile devices. Content can be stored in a raw format (such as Microsoft Word, Excel, PowerPoint, PDF, Text, HTML etc.) to which device-specific presentation styles can be applied.
Content access control
Access control includes authorization, authentication, access approval to each content. In many cases the access control also includes download control, wipe-out for specific user, time specific access. For the authentication, MCM shall have |
https://en.wikipedia.org/wiki/Telegony%20%28inheritance%29 | Telegony is a theory of heredity holding that offspring can inherit the characteristics of a previous mate of the female parent; thus the child of a woman might partake of traits of a previous sexual partner. Experiments in the late 19th century on several species failed to provide evidence that offspring would inherit any character from their mother's previous mates. It was superseded by the rediscovery of Mendelian inheritance and the Boveri–Sutton chromosome theory.
Etymology and description
Telegony is the idea that a female will be permanently affected the time she is first impregnated, since the fetus will pass back characteristics to her that will affect all future offspring, no matter their progeny.
The term was coined by August Weismann from the Greek words τῆλε (tèle) meaning 'far' and γονος (gonos) meaning 'offspring'.
Early perceptions
The idea of telegony goes back to Aristotle. It states that individuals can inherit traits not only from their fathers, but also from other males previously known to their mothers. In other words, it was thought that paternity could be shared.
Of a supposed Parnassos, founder of Delphi, Pausanias observes, "Like the other heroes, as they are called, he had two fathers; one they say was the god Poseidon, the human father being Cleopompus." Sometimes the result could be twins such as Castor and Pollux, one born divine and one mortal.
The more general doctrine of "maternal impressions" was also known in Ancient Israel. The book of Genesis describes Jacob inducing goats and sheep in Laban's herds to bear striped and spotted young by placing dark wooden rods with white stripes in their watering troughs. Telegony influenced early Christianity as well. The Gnostic followers of Valentinius (circa 100–160 CE) characteristically took the concept from the physiological world into the realm of psychology and spirituality by extending the supposed influence even to the thoughts of the woman. In the Gospel of Philip, a text a |
https://en.wikipedia.org/wiki/KSL%20cells | KSL cells in cell biology are an early form of mouse/murine hematopoietic stem cells. Characteristics are Kit (+), Sca-1 (+) and Lin (-). HSCs [Hematopoietic stem cells] in murine cultures show phenotypic markers as being CD34-, CD150+, and Flt3- for LTR [long-term reconstitution]. These phenotypic markers are used when purifying hematopoietic stem cells from the many other differentiated cells in the bone marrow.
Kit (CD117) is the receptor of Stem Cell Factor. Sca-1 is a murine hematopoietic stem cell antigen. Lin is a series of lineage marker antigens that identify mature murine blood cells.
Hematopoitic stem cells are of interest because of their ability to self-renew and differentiate into every types of blood cell. Transplantation of these cells in the bone marrow can be used to treat leukemia and other diseases of the blood and immune system. Murine/mouse cells lines are used as a model to research treatments before they are tested on humans.
See also
Cell biophysics
Cell disruption
Cell physiology
Cellular adaptation
Cellular microbiology
Outline of cell biology
Notes
University of Toronto, Faculty of Immunology,
J. Dick lab: Nat Immunol. 2010, 11:585; Science. 2011, 33 3:218
Rossi L, Challen GA, Sirin O, Lin KK, Goodell MA. Hematopoietic stem cell characterization and isolation. Methods Mol Biol. 2011;750:47-59.
doi: 10.1007/978-1-61779-145-1_3. PMID: 21618082; PMCID: PMC3621966.
Stem cells |
https://en.wikipedia.org/wiki/Yellowstone%20to%20Yukon%20Conservation%20Initiative | Yellowstone to Yukon Conservation Initiative or Y2Y is a transboundary Canada–United States not-for-profit organization that aims to connect and protect the Yellowstone-to-Yukon region. Its mission proposes to maintain and restore habitat integrity and connectivity along the spine of North America's Rocky Mountains stretching from the Greater Yellowstone ecosystem to Canada's Yukon Territory. It is the only organization dedicated to securing the long-term ecological health of the region.
Since 1993, more than 450 partner groups have joined forces to support the shared mission and vision. Y2Y's work is a collaborative effort of conservation groups, government agencies, Indigenous governments, landowners, wildlife scientists, planners, businesses, economists, and other individuals and groups interested in protecting native wildlife, ecological processes, and wilderness in the Rocky Mountains of North America. Existing national, state, and provincial parks and wilderness areas anchor the system, while the creation of new protected and special management areas provide the additional cores and corridors needed to complete it. This network is built upon the principles of conservation biology, various focal species assessments, the knowledge of local and traditional residents, and the requirements for sustainable economies.
Mission
Connecting and protecting habitat from Yellowstone to Yukon so people and nature can thrive.
Primary role
To achieve its vision across , Y2Y protects core wildlife habitats, keeps those habitats connected and inspires others to engage in similar work.
Y2Y highlights and focuses on local issues that have implications for the region as a whole. The organization engages in landscape-scale conservation, an approach that focuses on actions and management across large areas, such as entire watersheds.
The organization's role is to set the context for regional conservation work by providing the vision for a healthy Yellowstone to Yukon landscap |
https://en.wikipedia.org/wiki/Hypergraph%20regularity%20method | In mathematics, the hypergraph regularity method is a powerful tool in extremal graph theory that refers to the combined application of the hypergraph regularity lemma and the associated counting lemma. It is a generalization of the graph regularity method, which refers to the use of Szemerédi's regularity and counting lemmas.
Very informally, the hypergraph regularity lemma decomposes any given -uniform hypergraph into a random-like object with bounded parts (with an appropriate boundedness and randomness notions) that is usually easier to work with. On the other hand, the hypergraph counting lemma estimates the number of hypergraphs of a given isomorphism class in some collections of the random-like parts. This is an extension of Szemerédi's regularity lemma that partitions any given graph into bounded number parts such that edges between the parts behave almost randomly. Similarly, the hypergraph counting lemma is a generalization of the graph counting lemma that estimates number of copies of a fixed graph as a subgraph of a larger graph.
There are several distinct formulations of the method, all of which imply the hypergraph removal lemma and a number of other powerful results, such as Szemerédi's theorem, as well as some of its multidimensional extensions. The following formulations are due to V. Rödl, B. Nagle, J. Skokan, M. Schacht, and Y. Kohayakawa, for alternative versions see Tao (2006), and Gowers (2007).
Definitions
In order to state the hypergraph regularity and counting lemmas formally, we need to define several rather technical terms to formalize appropriate notions of pseudo-randomness (random-likeness) and boundedness, as well as to describe the random-like blocks and partitions.
Notation
denotes a -uniform clique on vertices.
is an -partite -graph on vertex partition .
is the family of all -element vertex sets that span the clique in . In particular, is a complete -partite -graph.
The following defines an important notion of relat |
https://en.wikipedia.org/wiki/Ball-jointed%20doll | A ball-jointed doll is any doll that is articulated with ball and socket joints. In contemporary usage when referring to modern dolls, and particularly when using the acronyms BJD or ABJD, it usually refers to modern Asian ball-jointed dolls. These are cast in polyurethane synthetic resin, a hard, dense plastic, and the parts strung together with a thick elastic. They are predominantly produced in Japan, South Korea and China. The BJD style has been described as both realistic and influenced by anime. They commonly range in size from about for the larger dolls, for the mini dolls, and down to for the very smallest BJDs. BJDs are primarily intended for adult collectors and customizers. They are made to be easy to customize, by painting, changing the eyes and wig, and so forth.
The modern BJD market began with the Volks line of Super Dollfie in 1999. Super Dollfie and Dollfie are registered trademarks but are sometimes erroneously used as generic blanket terms to refer to all Asian BJDs regardless of manufacturer.
History
Articulated dolls go back to at least 200 BCE, with articulated clay and wooden dolls of ancient Greece and Rome. The modern era of ball-jointed doll history began in Western Europe in the late 19th century. From the late 19th century through the early 20th century, French and German manufacturers made bisque dolls with strung bodies articulated with ball joints made of composition: a mix of pulp, sawdust, glue, and similar materials. These dolls could measure between and are now collectible antiques.
During the 1930s, the German artist Hans Bellmer created dolls with ball joints and used them in photography and other surrealistic artwork. Bellmer introduced the idea of artful doll photography, which continues today with Japanese doll artists, as well as BJD hobbyists.
Influenced by Bellmer and the rich Japanese doll tradition, Japanese artists began creating strung ball-jointed art dolls. These are commonly made entirely of bisque and are o |
https://en.wikipedia.org/wiki/%CE%92-Hydroxy%20%CE%B2-methylbutyric%20acid | β-Hydroxy β-methylbutyric acid (HMB), otherwise known as its conjugate base, , is a naturally produced substance in humans that is used as a dietary supplement and as an ingredient in certain medical foods that are intended to promote wound healing and provide nutritional support for people with muscle wasting due to cancer or HIV/AIDS. In healthy adults, supplementation with HMB has been shown to increase exercise-induced gains in muscle size, muscle strength, and lean body mass, reduce skeletal muscle damage from exercise, improve aerobic exercise performance, and expedite recovery from exercise. Medical reviews and meta-analyses indicate that HMB supplementation also helps to preserve or increase lean body mass and muscle strength in individuals experiencing age-related muscle loss. HMB produces these effects in part by stimulating the production of proteins and inhibiting the breakdown of proteins in muscle tissue. No adverse effects from long-term use as a dietary supplement in adults have been found.
HMB is sold as a dietary supplement at a cost of about per month when taking 3 grams per day. HMB is also contained in several nutritional products, including certain formulations of Ensure and Juven. HMB is also present in insignificant quantities in certain foods, such as alfalfa, asparagus, avocados, cauliflower, grapefruit, and catfish.
The effects of HMB on human skeletal muscle were first discovered by Steven L. Nissen at Iowa State University in the . HMB has not been banned by the National Collegiate Athletic Association, World Anti-Doping Agency, or any other prominent national or international athletic organization. In 2006, only about 2% of college student athletes in the United States used HMB as a dietary supplement. As of 2017, HMB has found widespread use as an ergogenic supplement among young athletes.
Uses
Available forms
HMB is sold as an over-the-counter dietary supplement in the free acid form, β-hydroxy β-methylbutyric acid (HMB-FA), a |
https://en.wikipedia.org/wiki/Intel%201103 | The 1103 is a dynamic random-access memory (DRAM) integrated circuit (IC) developed and fabricated by Intel. Introduced in October 1970, the 1103 was the first commercially available DRAM IC; and due to its small physical size and low price relative to magnetic-core memory, it replaced the latter in many applications. When it was introduced in 1970, initial production yields were poor, and it was not until the fifth stepping of the production masks that it became available in large quantities during 1971. Intel shipped the 250,000th 1103 RAM at June 1974.
Development
In 1969 William Regitz and his colleagues at Honeywell invented a three-transistor dynamic memory cell and began to canvass the semiconductor industry for a producer. The recently founded Intel Corporation responded and developed two very similar 1024-bit chips, the 1102 and 1103, under the lead of Joel Karp, working closely with William Regitz. Ultimately only the 1103 went into production.
Microsystems International became the first second source for the 1103 in 1971. Later National Semiconductor, Signetics, and Synertek manufactured the 1103 as well.
Technical details |
https://en.wikipedia.org/wiki/Flags%20of%20North%20America | This is a gallery of flags of North American countries, territories and their affiliated international organizations.
International organizations
Intercontinental organizations
Intracontinental organizations
Flags of North American sovereign states
Flags of North American dependencies and other territories
Flags of North American cities
Flags of cities with over 1 million inhabitants.
Historical flags
See also
List of sovereign states and dependent territories in North America
Subregions of North America
Lists of flags of North American countries
List of Antiguan and Barbudan flags
List of Bahamian flags
List of Barbadian flags
List of Belizean flags
List of Canadian flags
List of Costa Rican flags
List of Cuban flags
List of Dominican flags
List of Dominican Republic flags
List of Guatemalan flags
List of Haitian flags
List of Jamaican flags
List of Mexican flags
List of Nicaraguan flags
List of Trinidadian and Tobagonian flags
List of flags of the United States
North America
North America |
https://en.wikipedia.org/wiki/Linguistic%20diversity%20index | Linguistic diversity index (LDI) may refer to either Greenberg's (language) Diversity Index or the related Index of Linguistic Diversity (ILD) from Terralingua, which measures changes in the underlying LDI over time.
Greenberg's Diversity Index (LDI) is the probability that two people selected from the population at random will have different mother tongues; it therefore ranges from 0 (everyone has the same mother tongue) to 1 (no two people have the same mother tongue). The ILD measures how the LDI has changed over time; a global ILD of 0.8 indicates a 20% loss of diversity since 1970, but ratios above 1 are possible, and have appeared in regional indexes.
The computation of the diversity index is based on the population of each language as a proportion of the total population. The index cannot fully account for the vitality of languages. Also, the distinction between a language and a dialect is fluid and often political. A great number of languages are considered to be dialects of another language by some experts and separate languages by others. The index does not consider how different the languages are from each other, nor does it account for second language usage; it considers only the total number of distinct languages, and their relative frequency as mother tongues.
Rankings by country
See also
Ethnologue
Linguistic rights
List of official languages by country and territory
Number of languages by country
Notes and references
Notes |
https://en.wikipedia.org/wiki/Frontalis%20muscle | The frontalis muscle () is a muscle which covers parts of the forehead of the skull. Some sources consider the frontalis muscle to be a distinct muscle. However, Terminologia Anatomica currently classifies it as part of the occipitofrontalis muscle along with the occipitalis muscle.
In humans, the frontalis muscle only serves for facial expressions.
The frontalis muscle is supplied by the facial nerve and receives blood from the supraorbital and supratrochlear arteries.
Structure
The frontalis muscle is thin, of a quadrilateral form, and intimately adherent to the superficial fascia. It is broader than the occipitalis and its fibers are longer and paler in color. It is located on the front of the head.
The muscle has no bony attachments. Its medial fibers are continuous with those of the procerus; its intermediate fibers blend with the corrugator and orbicularis oculi muscles, thus attached to the skin of the eyebrows; and its lateral fibers are also blended with the latter muscle over the zygomatic process of the frontal bone.
From these attachments the fibers are directed upward, and join the galea aponeurotica below the coronal suture.
The medial margins of the frontalis muscles are joined together for some distance above the root of the nose; but between the occipitales there is a considerable, though variable, interval, occupied by the galea aponeurotica.
Function
In humans, the frontalis muscle only serves for facial expressions.
In the eyebrows, its primary function is to lift them (thus opposing the orbital portion of the orbicularis), especially when looking up. It also acts when a view is too distant or dim.
The frontalis muscle also serves to wrinkle the forehead.
Additional images
See also
Occipitofrontalis muscle |
https://en.wikipedia.org/wiki/First%20law%20of%20thermodynamics%20%28fluid%20mechanics%29 | In physics, the first law of thermodynamics is an expression of the conservation of total energy of a system. The increase of the energy of a system is equal to the sum of work done on the system and the heat added to that system:
where
is the total energy of a system.
is the work done on it.
is the heat added to that system.
In fluid mechanics, the first law of thermodynamics takes the following form:
where
is the Cauchy stress tensor.
is the flow velocity.
and is the heat flux vector.
Because it expresses conservation of total energy, this is sometimes referred to as the energy balance equation of continuous media. The first law is used to derive the non-conservation form of the Navier–Stokes equations.
Note
Where
is the pressure
is the identity matrix
is the deviatoric stress tensor
That is, pulling is positive stress and pushing is negative stress.
Compressible fluid
For a compressible fluid the left hand side of equation becomes:
because in general
Integral form
That is, the change in the internal energy of the substance within a volume is the negative of the amount carried out of the volume by the flow of material across the boundary plus the work done compressing the material on the boundary minus the flow of heat out through the boundary. More generally, it is possible to incorporate source terms.
Alternative representation
where is specific enthalpy, is dissipation function and is temperature. And where
i.e. internal energy per unit volume equals mass density times the sum of: proper energy per unit mass, kinetic energy per unit mass, and gravitational potential energy per unit mass.
i.e. change in heat per unit volume (negative divergence of heat flow) equals the divergence of heat conductivity times the gradient of the temperature.
i.e. divergence of work done against stress equals flow of material times divergence of stress plus stress times divergence of material flow.
i.e. stress times divergence of mat |
https://en.wikipedia.org/wiki/Permutotetraviridae | Permutotetraviridae is a family of viruses. Lepidopteran insects serve as natural hosts. The family contains one genus that has two species. Diseases associated with this family include: infection outcome varies from unapparent to lethal.
Taxonomy
Permutotetraviridae has one genus which contains two species:
Genus: Alphapermutotetravirus
Euprosterna elaeasa virus
Thosea asigna virus
Structure
Viruses in Permutotetraviridae are non-enveloped, with icosahedral geometries, and T=4 symmetry. The diameter is around 40 nm. Genomes are linear, around 5.6kb in length.
Life cycle
Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. Lepidopteran insectes serve as the natural host. Transmission routes are oral. |
https://en.wikipedia.org/wiki/Human%20penis | In human anatomy, the penis (; : penises or penes; from the Latin pēnis, initially "tail") is an external male intromittent organ that additionally serves as the urinary duct. The main parts are the root (radix); the body (corpus); and the epithelium of the penis including the shaft skin and the foreskin (prepuce) covering the glans penis. The body of the penis is made up of three columns of tissue: two corpora cavernosa on the dorsal side and corpus spongiosum between them on the ventral side. The human male urethra passes through the prostate gland, where it is joined by the ejaculatory duct, and then through the penis. The urethra traverses the corpus spongiosum, and its opening, the meatus (), lies on the tip of the glans penis. It is a passage both for urination and ejaculation of semen.
An erection is the stiffening expansion and orthogonal reorientation of the penis, which occurs during sexual arousal. Erections can occur in non-sexual situations; spontaneous non-sexual erections frequently occur during adolescence and sleep. In its flaccid state the penis is smaller, gives to pressure, and the glans is covered by the foreskin. In its fully erect state, the shaft becomes rigid and the glans becomes engorged but not rigid. An erect penis may be straight or curved and may point at an upward angle, a downward angle, or straight ahead. , the average erect human penis is long and has a circumference of . Neither age nor size of the flaccid penis accurately predicts erectile length. There are several common body modifications to the penis, including circumcision and piercings.
Anatomy
Parts
Root of the penis (radix): It is the attached part, consisting of the bulb of penis in the middle and the crus of penis, one on either side of the bulb. It lies within the superficial perineal pouch. The crus of penis is attached to the pubic arch.
Body of the penis (corpus): The pendulous part of the penis. It has two surfaces: dorsal (posterosuperior in the erect penis), |
https://en.wikipedia.org/wiki/Elliptic%20Gauss%20sum | In mathematics, an elliptic Gauss sum is an analog of a Gauss sum depending on an elliptic curve with complex multiplication. The quadratic residue symbol in a Gauss sum is replaced by a higher residue symbol such as a cubic or quartic residue symbol, and the exponential function in a Gauss sum is replaced by an elliptic function.
They were introduced by , at least in the lemniscate case when the elliptic curve has complex multiplication by , but seem to have been forgotten or ignored until the paper .
Example
gives the following example of an elliptic Gauss sum, for the case of an elliptic curve with complex multiplication by .
where
The sum is over residues mod whose representatives are Gaussian integers
is a positive integer
is a positive integer dividing
is a rational prime congruent to 1 mod 4
where is the sine lemniscate function, an elliptic function.
is the th power residue symbol in with respect to the prime of
is the field
is the field
is a primitive th root of 1
is a primary prime in the Gaussian integers with norm
is a prime in the ring of integers of lying above with inertia degree 1 |
https://en.wikipedia.org/wiki/ORCATS | ORCATS (Operational Research Computerised Allocation of Tickets to Services) is a large centralised legacy computer system used on passenger railways in Great Britain. It is used for real time reservation and revenue sharing on interavailable tickets between train operating companies (TOCs). The system is used to divide ticket revenue when a ticket or journey involves trains operated by multiple TOCs. The system was owned by British Rail, and is now managed by the Rail Delivery Group.
History
Before nationalisation, a similar function was carried out by the Railway Clearing House. |
https://en.wikipedia.org/wiki/X32%20Digital%20Mixing%20Console | The X32 Digital Mixing Console is a digital mixing console conceived and designed by German manufacturer Behringer. The console features 40-input channels, 25-bus, 32 XLR microphone input and 16 XLR output busses. The console features 25 100mm motorised faders, a user assignable control panel, Ethernet connectivity and an iPad and iPhone control application.
Behringer announces that its X32 live/recording digital console will be arriving in stores on or before July 27, 2012. |
https://en.wikipedia.org/wiki/Fax%20server | A fax server is a system installed in a local area network (LAN) server that allows computer users whose computers are attached to the LAN to send and receive fax messages.
Alternatively the term fax server is sometimes used to describe a program that enables a computer to send and receive fax messages, set of software running on a server computer which is equipped with one or more fax-capable modems (or dedicated fax boards) attached to telephone lines or, more recently, software modem emulators which use T.38 ("Fax over IP") technology to transmit the signal over an IP network. Its function is to accept documents from users, convert them into faxes, and transmit them, as well as to receive fax calls and either store the incoming documents or pass them on to users. Users may communicate with the server in several ways, through either a local network or the Internet. In a big organization with heavy fax traffic, the computer hosting the fax server may be dedicated to that function, in which case the computer itself may also be known as a fax server.
User interfaces
For outgoing faxes, several methods are available to the user:
An e-mail message (with optional attachments) can be sent to a special e-mail address; the fax server monitoring that address converts all such messages into fax format and transmits them.
The user can tell their computer to "print" a document using a "virtual printer" which, instead of producing a paper printout, sends the document to the fax server, which then transmits it.
A web interface can be used, allowing files to be uploaded, and transmitted to the fax server for faxing.
Special client software may be used.
For incoming faxes, several user interfaces may be available:
The user may be sent an e-mail message for each fax received, with the pages included as attachments, typically in either TIFF or PDF format.
Incoming faxes may be stored in a dedicated file directory, which the user can monitor.
A website may allow users to lo |
https://en.wikipedia.org/wiki/Trans-endocytosis | Trans-endocytosis is the biological process where material created in one cell undergoes endocytosis (enters) into another cell. If the material is large enough, this can be observed using an electron microscope. Trans-endocytosis from neurons to glia has been observed using time-lapse microscopy.
Trans-endocytosis also applies to molecules. For example, this process is involved when a part of the protein Notch is cleaved off and undergoes endocytosis into its neighboring cell. Without Notch trans-endocytosis, there would be too many neurons in a developing embryo. Trans-endocytosis is also involved in cell movement when the protein ephrin is bound by its receptor from a neighboring cell. |
https://en.wikipedia.org/wiki/Mediterranean%20Mathematics%20Competition | The Mediterranean Mathematics Competition (also: Peter O’Halloran Memorial) is a mathematics competition for school students, taking place annually since 1998. All countries bordering the Mediterranean Sea are allowed to participate, as well as, if invited, their neighbouring countries.
Motto
The Mediterranean Competition's goals are:
Discovery, development and challenge of mathematically gifted students
Establishment of friendly and cooperative relationships between students and teachers of various mediterranean countries
Creation of a possibility for international exchange about school practices
Support for the engagement in solving mathematical olympiad problems, as well as the dealing with other mathematical problems, also in non participating countries
Rules
The contest is conducted separately in every country. Each participating country can let an unrestricted number of students write the contest, but only the results of the top ten, according to national evaluation, can be submitted for international ranking. Every of these is awarded a certificate either of participation or merit, whereas the levels of merit - Gold, Silver, Bronze and Honorable Mention – are awarded similarly to the International Mathematical Olympiad. The participants have to be less than 20 years of age and may not have enrolled in a university study or a comparable educative scheme.
History
The Mediterranean Competition initially took place in 1998, created and until today organized by Spanish Francisco Bellot Rosado. In the first year, only three problems were to be solved. However from the second year on, the contest consisted of four problems each, with an overall contest time of four hours. |
https://en.wikipedia.org/wiki/Progerin | Progerin (UniProt# P02545-6) is a truncated version of the lamin A protein involved in the pathology of Hutchinson–Gilford progeria syndrome. Progerin is most often generated by a sporadic single point nucleotide polymorphism c.1824 C>T (GGC -> GGT, p.Gly608Gly) in the gene that codes for matured Lamin A. This mutation activates a cryptic splice site that induces a mutation in premature Lamin A with the deletion of a 50 amino acids group near the C-terminus. The endopeptidase ZMPSTE24 cannot cleave between the missing RSY - LLG amino acid sequence (as seen in the figure) during the maturation of Lamin A, due to the deletion of the 50 amino acids which included that sequence. This leaves the intact premature Lamin A bonded to the methylated carboxyl farnesyl group creating the defective protein Progerin, rather than the desired protein matured Lamin A. Approximately 90% of all Hutchinson–Gilford progeria syndrome cases are heterozygous for this deleterious single nucleotide polymorphism within exon 11 of the LMNA gene causing the post-translational modifications to produce Progerin. Lamin A constitutes a major structural component of the lamina, a scaffold of proteins found inside the nuclear membrane of a cell; progerin does not properly integrate into the lamina, which disrupts the scaffold structure and leads to significant disfigurement of the nucleus, characterized by a globular shape. Progerin activates genes that regulate stem cell differentiation via the Notch signaling pathway. Progerin increases the frequency of unrepaired double-strand breaks in DNA following exposure to ionizing radiation. Also, overexpression of progerin is correlated with an increase in non-homologous end joining relative to homologous recombination among those DNA double-strand breaks that are repaired. Furthermore, the fraction of homologous recombination events occurring by gene conversion is increased. These findings suggest that the normal untruncated nuclear lamina has an importan |
https://en.wikipedia.org/wiki/Flag%20of%20Orkney | The Flag of Orkney was the winner of a public flag consultation in February and March 2007. In the flag consultation the people of Orkney were asked for their preferred design from a short list of 5, all of which had been approved by the Court of the Lord Lyon. The chosen design was that of Duncan Tullock of Birsay, which polled 53% of the 200 votes cast by the public.
The colours red and yellow are from the Scottish and Norwegian royal coats of arms, which both use yellow and red, with a lion rampant. The flag symbolises the islands' Scottish and Norwegian heritage. The blue is taken from the flag of Scotland and also represents the sea and the maritime heritage of the islands.
Former flag of Orkney
The former flag of Orkney was adopted in 1995. In 2001, the flag of Orkney, the traditional flag of St Magnus, was declined official recognition by the Lord Lyon, the heraldic authority of Scotland, due to similarity with other national flags; as well as the flag of the Kalmar Union.
Chronology
See also
Flag of Shetland
Nordic Cross Flag
Royal Standard of Scotland
Royal Standard of Norway
Flag of Norway
List of Scottish flags
Emblems of the Kalmar Union |
https://en.wikipedia.org/wiki/Vpu%20protein | Vpu is an accessory protein that in HIV is encoded by the vpu gene. Vpu stands for "Viral Protein U". The Vpu protein acts in the degradation of CD4 in the endoplasmic reticulum and in the enhancement of virion release from the plasma membrane of infected cells. Vpu induces the degradation of the CD4 viral receptor and therefore participates in the general downregulation of CD4 expression during the course of HIV infection. Vpu-mediated CD4 degradation is thought to prevent CD4-Env binding in the endoplasmic reticulum to facilitate proper Env assembly into virions. It is found in the membranes of infected cells, but not the virus particles themselves.
The Vpu gene is found exclusively in HIV-1 and some HIV-1-related simian immunodeficiency virus (SIV) isolates, such as SIV, SIV, and SIV, but not in HIV-2 or the majority of SIV isolates. Structural similarities between Vpu and another small viral protein, M2, encoded by influenza A virus were first noted soon after the discovery of Vpu. Since then, Vpu has been shown to form cation-selective ion channels when expressed in Xenopus oocytes or mammalian cells and also when purified and reconstituted into planar lipid bilayers. Vpu also permeabilizes membranes of bacteria and mammalian cells to small molecules. Therefore, it is considered a member of the Viroporins family.
Expression
Vpu and Env are expressed from the same bicistronic mRNA in a Rev-dependent manner, presumably by leaky scanning of ribosomes through the vpu initiation codon. In fact Vpu gene overlaps at its 3′-end with the env gene. Several HIV-1 isolates were found to carry point mutations in the Vpu translation initiation codon but have otherwise intact vpu genes. Since removal of the Vpu initiation codon results in increased expression of the downstream env gene, it is possible that HIV-1 actually uses this mechanism as a molecular switch to regulate the relative expression of Vpu or Env in infected cells. The possible benefits of such a regulation |
https://en.wikipedia.org/wiki/Isomorphism-closed%20subcategory | In category theory, a branch of mathematics, a subcategory of a category is said to be isomorphism closed or replete if every -isomorphism with belongs to This implies that both and belong to as well.
A subcategory that is isomorphism closed and full is called strictly full. In the case of full subcategories it is sufficient to check that every -object that is isomorphic to an -object is also an -object.
This condition is very natural. For example, in the category of topological spaces one usually studies properties that are invariant under homeomorphisms—so-called topological properties. Every topological property corresponds to a strictly full subcategory of |
https://en.wikipedia.org/wiki/Liquid3 | Liquid 3 is an urban photobioreactor tank full of water and micro-algae installed as way to produce oxygen in cities that have high in the air. They also have sitting benches and solar energy panel next to them and can be used to fill urban pockets.
They may replace function of an adult tree. They have been used in Serbian cities, such as Belgrade. They are developed through UNDP. It contains 600 liters (159 gallons) of water and works by photosynthesis. |
https://en.wikipedia.org/wiki/Capillary%20electrophoresis%E2%80%93mass%20spectrometry | Capillary electrophoresis–mass spectrometry (CE–MS) is an analytical chemistry technique formed by the combination of the liquid separation process of capillary electrophoresis with mass spectrometry. CE–MS combines advantages of both CE and MS to provide high separation efficiency and molecular mass information in a single analysis. It has high resolving power and sensitivity, requires minimal volume (several nanoliters) and can analyze at high speed. Ions are typically formed by electrospray ionization, but they can also be formed by matrix-assisted laser desorption/ionization or other ionization techniques. It has applications in basic research in proteomics and quantitative analysis of biomolecules as well as in clinical medicine.
Since its introduction in 1987, new developments and applications have made CE-MS a powerful separation and identification technique. Use of CE–MS has increased for protein and peptides analysis and other biomolecules. However, the development of online CE–MS is not without challenges. Understanding of CE, the interface setup, ionization technique and mass detection system is important to tackle problems while coupling capillary electrophoresis to mass spectrometry.
History
The original interface between capillary zone electrophoresis and mass spectrometry was developed in 1987 by Richard D. Smith and coworkers at Pacific Northwest National Laboratory, and who also later were involved in development of interfaces with other CE variants, including capillary isotachophoresis and capillary isoelectric focusing.
Sample injection
There are two common techniques to load the sample into CE–MS system, which is similar to approaches for traditional CE: hydrodynamic and electrokinetic injection.
Hydrodynamic injection
For loading the analytes, the capillary is firstly placed into sample vial. Then there are different ways for hydrodynamic injection: it can be applied positive pressure to inlet, negative pressure to outlet or the sample inlet |
https://en.wikipedia.org/wiki/Stick%20PC | A stick PC or PC on a stick is a single-board computer in a small elongated casing resembling a stick, that can usually be plugged directly (without an HDMI cable) into an HDMI video port. A stick PC is a device which has independent CPUs or processing chips and which does not rely on another computer. It should not be confused with passive storage devices such as thumb drives.
A stick PC can be connected to a peripheral device such as a monitor, TV, or kiosk display to produce visual or audio output. Stick PCs generally have limited computing power and are not suited for intensive tasks, but can be suitable in other applications that do not require such power.
History
The stick PC was first introduced in 2003. The Gumstix, which came out that same year, used the ARM architecture system on a chip (SoC) and the Linux 2.6 kernel. Windows CE can be installed on this stick. It was based on the idea of making a PC similar in size to that of an average stick of chewing gum.
As the popularity of smart TVs and set-top boxes to view streaming services (such as the Roku) grew, companies started looking at making these small computers even smaller and easier to use.
Several stick PCs using ARM architecture SoCs were introduced around 2012, made of sticks pluggable in an HDMI port, including the Android Mini PC MK802 series from Rikomagic, using Android or Linux distributions, both based on Linux and Allwinner Technology or Rockchip SoC and Cotton Candy, using Samsung Exynos SoC.
2013-2014 saw several manufacturers come out with stick PCs. MeeGoPad released the first x86 based stick PC, featuring the Intel Atom Z3735F Processor. In April 2013, Tronsmart released the MK908, using the Rockchip RK3188 (featuring the quad-core ARM Cortex-A9 and ARM Mali-400MP GPU). On July 24, 2013, Google introduced the Google Chromecast, a streaming device similar in function and design to a stick PC. On November 19, 2014, Amazon released a smaller version of the Amazon Fire TV called the |
https://en.wikipedia.org/wiki/Murashige%20and%20Skoog%20medium | Murashige and Skoog medium (or MSO or MS0 (MS-zero)) is a plant growth medium used in the laboratories for cultivation of plant cell culture. MS0 was invented by plant scientists Toshio Murashige and Folke K. Skoog in 1962 during Murashige's search for a new plant growth regulator. A number behind the letters MS is used to indicate the sucrose concentration of the medium. For example, MS0 contains no sucrose and MS20 contains 20 g/L sucrose. Along with its modifications, it is the most commonly used medium in plant tissue culture experiments in the laboratory. However, according to recent scientific findings, MS medium is not suitable as a nutrient solution for deep water culture or hydroponics.
As Skoog's doctoral student, Murashige originally set out to find an as-yet undiscovered growth hormone present in tobacco juice. No such component was discovered; instead, analysis of juiced tobacco and ashed tobacco revealed higher concentrations of specific minerals in plant tissues than were previously known. A series of experiments demonstrated that varying the levels of these nutrients enhanced growth substantially over existing formulations. It was determined that nitrogen in particular enhanced growth of tobacco in tissue culture.
Ingredients
Major salts (macronutrients) per litre
Ammonium nitrate (NH4NO3) 1650 mg/l
Calcium chloride (CaCl2 · 2H2O) 440 mg/l
Magnesium sulfate (MgSO4 · 7H2O) 180.7 mg/l
Monopotassium phosphate (KH2PO4) 170 mg/l
Potassium nitrate (KNO3) 1900 mg/l.
Minor salts (micronutrients) per litre
Boric acid (H3BO3) 6. 2 mg/l
Cobalt chloride (CoCl2 · 6H2O) 0.025 mg/l
Ferrous sulfate (FeSO4 · 7H2O) 27.8 mg/l
Manganese(II) sulfate (MnSO4 · 4H2O) 22.3 mg/l
Potassium iodide (KI) 0.83 mg/l
Sodium molybdate (Na2MoO4 · 2H2O) 0.25 mg/l
Zinc sulfate (ZnSO4·7H2O) 8.6 mg/l
Ethylenediaminetetraacetic acid ferric sodium (FeNaEDTA) 36.70 mg/L
Copper sulfate (CuSO4 · 5H2O) 0.025 mg/l
Vitamins and organic compounds per litre
Myo-Inositol 100 mg/l
Nicotini |
https://en.wikipedia.org/wiki/Single-atom%20transistor | A single-atom transistor is a device that can open and close an electrical circuit by the controlled and reversible repositioning of one single atom. The single-atom transistor was invented and first demonstrated in 2002 by Dr. Fangqing Xie in Prof. Thomas Schimmel's Group at the Karlsruhe Institute of Technology (former University of Karlsruhe). By means of a small electrical voltage applied to a control electrode, the so-called gate electrode, a single silver atom is reversibly moved in and out of a tiny junction, in this way closing and opening an electrical contact.
Therefore, the single-atom transistor works as an atomic switch or atomic relay, where the switchable atom opens and closes the gap between two tiny electrodes called source and drain. The single-atom transistor opens perspectives for the development of future atomic-scale logics and quantum electronics.
At the same time, the device of the Karlsruhe team of researchers marks the lower limit of miniaturization, as feature sizes smaller than one atom cannot be produced lithographically. The device represents a quantum transistor, the conductance of the source-drain channel being defined by the rules of quantum mechanics. It can be operated at room temperature and at ambient conditions, i.e. neither cooling nor vacuum are required.
Few atom transistors have been developed at Waseda University and at Italian CNR by Takahiro Shinada and Enrico Prati, who observed the Anderson–Mott transition in miniature by employing arrays of only two, four and six individually implanted As or P atoms.
See also
QFET (quantum field-effect transistor) |
https://en.wikipedia.org/wiki/Solovay%E2%80%93Strassen%20primality%20test | The Solovay–Strassen primality test, developed by Robert M. Solovay and Volker Strassen in 1977, is a probabilistic test to determine if a number is composite or probably prime. The idea behind the test was discovered by M. M. Artjuhov in 1967
(see Theorem E in the paper). This test has been largely superseded by the Baillie–PSW primality test and the Miller–Rabin primality test, but has great historical importance in showing the practical feasibility of the RSA cryptosystem. The Solovay–Strassen test is essentially an Euler–Jacobi probable prime test.
Concepts
Euler proved that for any odd prime number p and any integer a,
where is the Legendre symbol. The Jacobi symbol is a generalisation of the Legendre symbol to , where n can be any odd integer. The Jacobi symbol can be computed in time O((log n)²) using Jacobi's generalization of the
law of quadratic reciprocity.
Given an odd number n we can contemplate whether or not the congruence
holds for various values of the "base" a, given that a is relatively prime to n. If n is prime then this congruence is true for all a. So if we pick values of a at random and test the congruence, then
as soon as we find an a which doesn't fit the congruence we know that n is not prime (but this does not tell us a nontrivial factorization of n). This base a is called an Euler witness for n; it is a witness for the compositeness of n. The base a is called an Euler liar for n if the congruence is true while n is composite.
For every composite odd n, at least half of all bases
are (Euler) witnesses as the set of Euler liars is a proper subgroup of . For example, for , the set of Euler liars has order 8 and , and has order 48.
This contrasts with the Fermat primality test, for which the proportion of witnesses may be much smaller. Therefore, there are no (odd) composite n without many witnesses, unlike the case of Carmichael numbers for Fermat's test.
Example
Suppose we wish to determine if n = 221 is prime. We write (n−1 |
https://en.wikipedia.org/wiki/Sociocultural%20system | A sociocultural system is a "human population viewed (1) in its ecological context and (2) as one of the many subsystems of a larger ecological system".
The term "sociocultural system" embraces three concepts: society, culture, and system. A society is a number of interdependent organisms of the same species. A culture is the learned behaviors that are shared by the members of a society, together with the material products of such behaviors. The words "society" and "culture" are fused together to form the word "sociocultural". A system is "a collection of parts which interact with each other to function as a whole". The term sociocultural system is most likely to be found in the writings of anthropologists who specialize in ecological anthropology.
In 1979, Marvin Harris outlined a universal structure of sociocultural systems. He mentioned infrastructure (production and population), structure (which is behavioural, like corporations, political organizations, hierarchies, castes), and a superstructure (which is mental, like beliefs, values, norms).
See also |
https://en.wikipedia.org/wiki/Ammonifex | Ammonifex is a Gram-negative, extremely thermophilic, strictly anaerobic and motile genus of bacteria from the family of Thermoanaerobacteraceae. |
https://en.wikipedia.org/wiki/EMX%20homeogene | The Emx gene family has two members: EMX1 and EMX2. The Emx genes are responsible for encoding these two transcription factors; the homeodomain is responsible for binding to target DNA sequences to regulate transcription. |
https://en.wikipedia.org/wiki/Krull%20dimension | In commutative algebra, the Krull dimension of a commutative ring R, named after Wolfgang Krull, is the supremum of the lengths of all chains of prime ideals. The Krull dimension need not be finite even for a Noetherian ring. More generally the Krull dimension can be defined for modules over possibly non-commutative rings as the deviation of the poset of submodules.
The Krull dimension was introduced to provide an algebraic definition of the dimension of an algebraic variety: the dimension of the affine variety defined by an ideal I in a polynomial ring R is the Krull dimension of R/I.
A field k has Krull dimension 0; more generally, k[x1, ..., xn] has Krull dimension n. A principal ideal domain that is not a field has Krull dimension 1. A local ring has Krull dimension 0 if and only if every element of its maximal ideal is nilpotent.
There are several other ways that have been used to define the dimension of a ring. Most of them coincide with the Krull dimension for Noetherian rings, but can differ for non-Noetherian rings.
Explanation
We say that a chain of prime ideals of the form
has length n. That is, the length is the number of strict inclusions, not the number of primes; these differ by 1. We define the Krull dimension of to be the supremum of the lengths of all chains of prime ideals in .
Given a prime ideal in R, we define the of , written , to be the supremum of the lengths of all chains of prime ideals contained in , meaning that . In other words, the height of is the Krull dimension of the localization of R at . A prime ideal has height zero if and only if it is a minimal prime ideal. The Krull dimension of a ring is the supremum of the heights of all maximal ideals, or those of all prime ideals. The height is also sometimes called the codimension, rank, or altitude of a prime ideal.
In a Noetherian ring, every prime ideal has finite height. Nonetheless, Nagata gave an example of a Noetherian ring of infinite Krull dimension. A ring is called |
https://en.wikipedia.org/wiki/Radioactive%20decay | Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered radioactive. Three of the most common types of decay are alpha, beta, and gamma decay. The weak force is the mechanism that is responsible for beta decay, while the other two are governed by the electromagnetism and nuclear force.
Radioactive decay is a stochastic (i.e. random) process at the level of single atoms. According to quantum theory, it is impossible to predict when a particular atom will decay, regardless of how long the atom has existed. However, for a significant number of identical atoms, the overall decay rate can be expressed as a decay constant or as half-life. The half-lives of radioactive atoms have a huge range; from nearly instantaneous to far longer than the age of the universe.
The decaying nucleus is called the parent radionuclide (or parent radioisotope), and the process produces at least one daughter nuclide. Except for gamma decay or internal conversion from a nuclear excited state, the decay is a nuclear transmutation resulting in a daughter containing a different number of protons or neutrons (or both). When the number of protons changes, an atom of a different chemical element is created.
There are 28 naturally occurring chemical elements on Earth that are radioactive, consisting of 34 radionuclides (6 elements have 2 different radionuclides) that date before the time of formation of the Solar System. These 34 are known as primordial nuclides. Well-known examples are uranium and thorium, but also included are naturally occurring long-lived radioisotopes, such as potassium-40.
History of discovery
Radioactivity was discovered in 1896 by scientists Henri Becquerel and Marie Skłodowska-Curie, while working with phosphorescent materials. These materials glow in the dark after exposure to ligh |
https://en.wikipedia.org/wiki/Machine%20element | Machine element or hardware refers to an elementary component of a machine. These elements consist of three basic types:
structural components such as frame members, bearings, axles, splines, fasteners, seals, and lubricants,
mechanisms that control movement in various ways such as gear trains, belt or chain drives, linkages, cam and follower systems, including brakes and clutches, and
control components such as buttons, switches, indicators, sensors, actuators and computer controllers.
While generally not considered to be a machine element, the shape, texture and color of covers are an important part of a machine that provide a styling and operational interface between the mechanical components of a machine and its users.
Machine elements are basic mechanical parts and features used as the building blocks of most machines. Most are standardized to common sizes, but customs are also common for specialized applications.
Machine elements may be features of a part (such as screw threads or integral plain bearings) or they may be discrete parts in and of themselves such as wheels, axles, pulleys, rolling-element bearings, or gears. All of the simple machines may be described as machine elements, and many machine elements incorporate concepts of one or more simple machines. For example, a leadscrew incorporates a screw thread, which is an inclined plane wrapped around a cylinder.
Many mechanical design, invention, and engineering tasks involve a knowledge of various machine elements and an intelligent and creative combining of these elements into a component or assembly that fills a need (serves an application).
Structural elements
Beams,
Struts,
Bearings,
Fasteners
Keys,
Splines,
Cotter pin,
Seals
Machine guardings
Mechanical elements
Engine,
Electric motor,
Actuator,
Shafts,
Couplings
Belt,
Chain,
Cable drives,
Gear train,
Clutch,
Brake,
Flywheel,
Cam,
follower systems,
Linkage,
Simple machine
Types
Shafts |
https://en.wikipedia.org/wiki/Artificial%20seawater | Artificial seawater (abbreviated ASW) is a mixture of dissolved mineral salts (and sometimes vitamins) that simulates seawater. Artificial seawater is primarily used in marine biology and in marine and reef aquaria, and allows the easy preparation of media appropriate for marine organisms (including algae, bacteria, plants and animals). From a scientific perspective, artificial seawater has the advantage of reproducibility over natural seawater since it is a standardized formula. Artificial seawater is also known as synthetic seawater and substitute ocean water.
Example
The tables below present an example of an artificial seawater (35.00‰ of salinity) preparation devised by Kester, Duedall, Connors and Pytkowicz (1967). The recipe consists of two lists of mineral salts, the first of anhydrous salts that can be weighed out, the second of hydrous salts that should be added to the artificial seawater as a solution.
While all of the compounds listed in the recipe above are inorganic, mineral salts, some artificial seawater recipes, such as Goldman and McCarthy (1978), make use of trace solutions of vitamins or organic compounds.
Standard
The International Standard for making artificial seawater can be found at ASTM International. The current standard is named ASTM D1141-98 (The original standard was ASTM D1141-52) and describes the standard practice for the preparation of substitute ocean water.
The ASTM D1141-98 standard comes in a ready-made artificial seawater form or a "Sea Salt" mix that can be prepared by engineers and hobbyists. Generally, the ready-made artificial seawater comes in 1 gallon and 5 gallon containers, whereas the "Sea Salt" mix comes in 20lb pails (makes approximately 57 gallons) and 50lb pails (makes approximately 143 gallons).
Uses and applications
There are various applications for ASTM D1141-98 synthetic seawater including corrosion studies, ocean instrument calibration and chemical processing. Typically, laboratory-grade water is used wh |
https://en.wikipedia.org/wiki/Topiary | Topiary is the horticultural practice of training perennial plants by clipping the foliage and twigs of trees, shrubs and subshrubs to develop and maintain clearly defined shapes, whether geometric or fanciful. The term also refers to plants which have been shaped in this way. As an art form it is a type of living sculpture. The word derives from the Latin word for an ornamental landscape gardener, topiarius, a creator of topia or "places", a Greek word that Romans also applied to fictive indoor landscapes executed in fresco.
The plants used in topiary are evergreen, mostly woody, have small leaves or needles, produce dense foliage, and have compact and/or columnar (e.g., fastigiate) growth habits. Common species chosen for topiary include cultivars of European box (Buxus sempervirens), arborvitae (Thuja species), bay laurel (Laurus nobilis), holly (Ilex species), myrtle (Eugenia or Myrtus species), yew (Taxus species), and privet (Ligustrum species). Shaped wire cages are sometimes employed in modern topiary to guide untutored shears, but traditional topiary depends on patience and a steady hand; small-leaved ivy can be used to cover a cage and give the look of topiary in a few months. The hedge is a simple form of topiary used to create boundaries, walls or screens.
History
Origin
European topiary dates from Roman times. Pliny's Natural History and the epigram writer Martial both credit Gaius Matius Calvinus, in the circle of Julius Caesar, with introducing the first topiary to Roman gardens, and Pliny the Younger describes in a letter the elaborate figures of animals, inscriptions, cyphers and obelisks in clipped greens at his Tuscan villa (Epistle v.6, to Apollinaris). Within the atrium of a Roman house or villa, a place that had formerly been quite plain, the art of the topiarius produced a miniature landscape (topos) which might employ the art of stunting trees, also mentioned, disapprovingly, by Pliny (Historia Naturalis xii.6).
Far Eastern topiary
The |
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