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https://en.wikipedia.org/wiki/Newman%E2%80%93Penrose%20formalism
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The Newman–Penrose (NP) formalism is a set of notation developed by Ezra T. Newman and Roger Penrose for general relativity (GR). Their notation is an effort to treat general relativity in terms of spinor notation, which introduces complex forms of the usual variables used in GR. The NP formalism is itself a special case of the tetrad formalism, where the tensors of the theory are projected onto a complete vector basis at each point in spacetime. Usually this vector basis is chosen to reflect some symmetry of the spacetime, leading to simplified expressions for physical observables. In the case of the NP formalism, the vector basis chosen is a null tetrad: a set of four null vectors—two real, and a complex-conjugate pair. The two real members often asymptotically point radially inward and radially outward, and the formalism is well adapted to treatment of the propagation of radiation in curved spacetime. The Weyl scalars, derived from the Weyl tensor, are often used. In particular, it can be shown that one of these scalars— in the appropriate frame—encodes the outgoing gravitational radiation of an asymptotically flat system.
Newman and Penrose introduced the following functions as primary quantities using this tetrad:
Twelve complex spin coefficients (in three groups) which describe the change in the tetrad from point to point: .
Five complex functions encoding Weyl tensors in the tetrad basis: .
Ten functions encoding Ricci tensors in the tetrad basis: (real); (complex).
In many situations—especially algebraically special spacetimes or vacuum spacetimes—the Newman–Penrose formalism simplifies dramatically, as many of the functions go to zero. This simplification allows for various theorems to be proven more easily than using the standard form of Einstein's equations.
In this article, we will only employ the tensorial rather than spinorial version of NP formalism, because the former is easier to understand and more popular in relevant papers. One can refe
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https://en.wikipedia.org/wiki/Articulation%20of%20head%20of%20rib
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The articulations of the heads of the ribs (or costocentral articulations) constitute a series of gliding or arthrodial joints, and are formed by the articulation of the heads of the typical ribs with the costal facets on the contiguous margins of the bodies of the thoracic vertebrae and with the intervertebral discs between them; the first, eleventh and twelfth ribs each articulate with a single vertebra.
Two convex facets from the head attach to two adjacent vertebrae, at the inferior costal facet of the superior vertebra, and the superior costal facet of the inferior vertebra respectively. This forms the synovial planar (gliding) joint.
The ligaments of the joints are:
Intra-articular ligament of head of rib
Radiate ligament of head of rib
Additional images
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https://en.wikipedia.org/wiki/Costovertebral%20joints
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The costovertebral joints are the joints that connect the ribs to the vertebral column.
The articulation of the head of rib connects the head of the rib and the bodies of vertebrae.
The costotransverse joint connects the rib with the transverse processes of vertebrae.
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https://en.wikipedia.org/wiki/BB84
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BB84 is a quantum key distribution scheme developed by Charles Bennett and Gilles Brassard in 1984. It is the first quantum cryptography protocol. The protocol is provably secure assuming a perfect implementation, relying on two conditions: (1) the quantum property that information gain is only possible at the expense of disturbing the signal if the two states one is trying to distinguish are not orthogonal (see no-cloning theorem); and (2) the existence of an authenticated public classical channel. It is usually explained as a method of securely communicating a private key from one party to another for use in one-time pad encryption.
The proof of BB84 depends on a perfect implementation. Side channel attacks exist, taking advantage of non-quantum sources of information. Since this information is non-quantum, it can be intercepted without measuring or cloning quantum particles.
Description
In the BB84 scheme, Alice wishes to send a private key to Bob. She begins with two strings of bits, and , each bits long. She then encodes these two strings as a tensor product of qubits:
where and are the -th bits of and respectively. Together, give us an index into the following four qubit states:
Note that the bit is what decides which basis is encoded in (either in the computational basis or the Hadamard basis). The qubits are now in states that are not mutually orthogonal, and thus it is impossible to distinguish all of them with certainty without knowing .
Alice sends over a public and authenticated quantum channel to Bob. Bob receives a state , where represents both the effects of noise in the channel and eavesdropping by a third party we'll call Eve. After Bob receives the string of qubits, both Bob and Eve have their own states. However, since only Alice knows , it makes it virtually impossible for either Bob or Eve to distinguish the states of the qubits. Also, after Bob has received the qubits, we know that Eve cannot be in possession of a cop
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https://en.wikipedia.org/wiki/Saint%20Patrick%27s%20Saltire
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Saint Patrick's Saltire or Saint Patrick's Cross is a red saltire (X-shaped cross) on a white field. In heraldic language, it may be blazoned "argent, a saltire gules". The Saint Patrick's Flag (Bratach Naomh Pádraig) is a flag composed of Saint Patrick's Saltire. The origin of the saltire is disputed. Its association with Saint Patrick dates from the 1780s, when the Anglo-Irish Order of Saint Patrick adopted it as an emblem. This was a British chivalric order established in 1783 by George III. It has been suggested that it derives from the arms of the powerful Geraldine or FitzGerald dynasty. Some Irish nationalists and others reject its use to represent Ireland as a "British invention" "for a people who had never used it".
After its adoption by the Order of Saint Patrick, it began to be used by other institutions. When the Acts of Union 1800 joined the Kingdom of Ireland with the Kingdom of Great Britain, the saltire was added to the British flag to form the Union Flag still used by the United Kingdom. The saltire has occasionally served unofficially to represent Northern Ireland and also appears in some royal events.
Origins
An early possible mention of a Saint Patrick's flag is from the journal of John Glanville, writing about the Anglo-Dutch fleet that sailed to Cádiz, Spain, in 1625. Lord Delaware deposed in writing to the Lieutenant General about his simple foretop (white, red or blue) precedence flags to be flown:
The Order of Saint Patrick, an Anglo-Irish chivalric order, was created in 1783. The order was a means of rewarding those in high office who supported the Anglo-Irish government of Ireland. On its badge was a red saltire on a white background, which it called the "Cross of St Patrick":
The use of a saltire in association with St Patrick was controversial because it differed from the usual crosses by custom worn on St Patrick's Day. In particular, the previous crosses associated with Saint Patrick were not X-shaped. Some contemporary response
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https://en.wikipedia.org/wiki/Human%20%CE%B2-globin%20locus
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The human β-globin locus is composed of five genes located on a short region of chromosome 11, responsible for the creation of the beta parts (roughly half) of the oxygen transport protein Haemoglobin. This locus contains not only the beta globin gene but also delta, gamma-A, gamma-G, and epsilon globin. Expression of all of these genes is controlled by single locus control region (LCR), and the genes are differentially expressed throughout development.
The order of the genes in the beta-globin cluster is: 5' - epsilon – gamma-G – gamma-A – delta – beta - 3'.
The arrangement of the genes directly reflects the temporal differentiation of their expression during development, with the early-embryonic stage version of the gene located closest to the LCR. If the genes are rearranged, the gene products are expressed at improper stages of development.
Expression of these genes is regulated in embryonic erythropoiesis by many transcription factors, including KLF1, which is associated with the upregulation of adult hemoglobin in adult definitive erythrocytes, and KLF2, which is vital to the expression of embryonic hemoglobin.
HBB complex
Many CRMs have been mapped within the cluster of genes encoding β-like globins expressed in embryonic (HBE1), fetal (HBG1 and HBG2), and adult (HBB and HBD) erythroid cells. All are marked by DNase I hypersensitive sites and footprints, and many are bound by GATA1 in peripheral blood derived erythroblasts (PBDEs). A DNA segment located between the HBG1 and HBD genes is one of the DNA segments bound by BCL11A and several other proteins to negatively regulate HBG1 and HBG2. It is sensitive to DNase I but is not conserved across mammals. An enhancer located 3′ of the HBG1 gene is bound by several proteins in PBDEs and K562 cells and is sensitive to DNase I, but shows almost no signal for mammalian constraint.
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https://en.wikipedia.org/wiki/1%3A18%20scale%20diecast
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1:18 scale diecast replicas are 1/18th the size of the real vehicle. Most popular in this category are 1:18 scale automobile replicas – usually made out of Zamak zinc diecasting alloy with plastic parts. "1:18 scale" is the colloquial reference to this class of toy or replica.
Description
Virtually all 1:18 scale models produced in recent years have opening doors, hoods, and trunks along with functional steering wheels which turn the front wheels. Tires are often mounted on workable 'springy' suspension systems. Normally the hood / bonnet lifts to reveal a detailed and accurate engine bay (whether this is a separate cast piece or simply a portion of the cast and painted body located between the fenders).
Higher end models are equipped with genuine leather interiors, accurate engine detail, operational sunroofs, movable windshield wipers, adjustable seats, operational gear levers and other realistic accessories. Most models are approximately long by wide by tall, depending on what vehicle is being represented. Such detail is common to 1:18 scales and larger. Typically, and according to local law, companies that produce model cars will have licensing arrangements with real car manufacturers to make replicas of their cars, both in current production or of discontinued models.
History
How 1:18 scale became a standard in diecast, especially during the 1990s, is somewhat of a question, but some of the first 1:18 scale cars appeared made in tin in the United States and Japan after World War II. These, however, were not precise in detail or proportion, but became popular in the late 1950s and early 1960s. Before World War II, some vehicle appeared in this size. Also rather by chance, other manufacturers, like Marx in the 1960s and 1970s simply made 1:18 scale large plastic toys. Plastic models in the United States, though, normally were produced in 1:25 scale.
The first zinc alloy metal cars in this scale (and also 1:24 scale) from European Manufacturers appeared ar
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https://en.wikipedia.org/wiki/Synexpression
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Synexpression is a type of non-random eukaryotic gene organization. Genes in a synexpression group may not be physically linked, but they are involved in the same process and they are coordinately expressed. It is expected that genes that function in the same process be regulated coordinately. Synexpression groups in particular represent genes that are simultaneously up- or down-regulated, often because their gene products are required in stoichiometric amounts or are protein-complex subunits. It is likely that these gene groups share common cis- and trans-acting control elements to achieve coordinate expression.
Synexpression groups are determined mainly by analysis of expression profiles compiled by the use of DNA microarrays. The use of this technology helps researchers monitor changes in expression patterns for large numbers of genes in a given experiment. Analysis of DNA microarray expression profiles has led to the discovery of a number of genes that are tightly co-regulated.
Identification
The identification of synexpression groups has affected the way some scientists view evolutionary change in higher eukaryotes. Since groups of genes involved in the same biological process often share one or more common control elements, it has been suggested that the differential expression of these synexpression groups in different tissues of organisms can contribute to co-evolution tissues, organs, and appendages. Today it is commonly believed that it is not primarily the gene products themselves that evolve, but that it is the control networks for groups of genes that contribute most to the evolution of higher eukaryotes.
Development
Developmental processes provide an example of how changes in synexpression control networks could significantly affect an organism's capacity to evolve and adapt effectively. In animals, it is often beneficial for appendages to co-evolve, and it has been observed that fore-and hind-limbs share expression of Hox genes early in me
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https://en.wikipedia.org/wiki/Margent
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Margent is a vertical arrangement of flowers, leaves or hanging vines used as a decorative ornament in architecture and furniture design in the 16th, 17th and 18th centuries. This motif was developed as a complement to other decorative ornaments, hanging as "drops" at the ends of a festoon or swag. Also used to accentuate the vertical lines of window frames and centered in ornamental panels.
The term margent is an archaic word meaning "margin", a border or edge; especially handwriting on the edges of a printed book (or marginalia). Related to the word "marches", the area between two regions.
Shakespeare uses the word in Act II, Scene I of A Midsummer Night's Dream:
These are the forgeries of jealousy
And never, since the middle summer's spring,
Met we on hill, in dale, forest or mead,
By paved fountain or by rushy brook,
Or in the beached margent of the sea,
To dance our ringlets to the whistling wind,
But with thy brawls thou hast disturb'd our sport.
—Titania, the queen of the fairies
Beached Margent of the Sea is also the name of a painting by Canadian artist, F.M. Bell-Smith (1846–1923).
See also
Marginalia
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https://en.wikipedia.org/wiki/Deoxycytidine%20triphosphate
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Deoxycytidine triphosphate (dCTP) is a nucleoside triphosphate that contains the pyrimidine base cytosine. The triphosphate group contains high-energy phosphoanhydride bonds, which liberate energy when hydrolized.
DNA polymerase enzymes use this energy to incorporate deoxycytidine into a newly synthesized strand of DNA. A chemical equation can be written that represents the process:
(DNA)n + dCTP ↔ (DNA)n-C + PPi
That is, dCTP has the PPi (pyrophosphate) cleaved off and the dCMP is incorporated into the DNA strand at the 3' end.
Subsequent hydrolysis of the PPi drives the equilibrium of the reaction toward the right side, i.e. incorporation of the nucleotide in the growing DNA chain.
Like other nucleoside triphosphates, manufacturers recommend that dCTP be stored in aqueous solution at −20 °C.
See also
DNA replication
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https://en.wikipedia.org/wiki/Distributed%20minimum%20spanning%20tree
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The distributed minimum spanning tree (MST) problem involves the construction of a minimum spanning tree by a distributed algorithm, in a network where nodes communicate by message passing. It is radically different from the classical sequential problem, although the most basic approach resembles Borůvka's algorithm. One important application of this problem is to find a tree that can be used for broadcasting. In particular, if the cost for a message to pass through an edge in a graph is significant, an MST can minimize the total cost for a source process to communicate with all the other processes in the network.
The problem was first suggested and solved in time in 1983 by Gallager et al., where is the number of vertices in the graph. Later, the solution was improved to and finally
where D is the network, or graph diameter. A lower bound on the time complexity of the solution has been eventually shown to be
Overview
The input graph is considered to be a network, where vertices are independent computing nodes and edges are communication links. Links are weighted as in the classical problem.
At the beginning of the algorithm, nodes know only the weights of the links which are connected to them. (It is possible to consider models in which they know more, for example their neighbors' links.)
As the output of the algorithm, every node knows which of its links belong to the minimum spanning tree and which do not.
MST in message-passing model
The message-passing model is one of the most commonly used models in distributed computing. In this model, each process is modeled as a node of a graph. Each communication channel between two processes is an edge of the graph.
Two commonly used algorithms for the classical minimum spanning tree problem are Prim's algorithm and Kruskal's algorithm. However, it is difficult to apply these two algorithms in the distributed message-passing model. The main challenges are:
Both Prim's algorithm and Kruskal's algorithm requ
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https://en.wikipedia.org/wiki/Rheophile
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A rheophile is an animal that prefers to live in fast-moving water.
Examples of rheophilic animals
Insects
Many aquatic insects living in riffles require current to survive.
Epeorus sylvicola, a rheophilic mayfly species (Ephemeroptera)
Some African (Elattoneura) and Asian threadtail (Prodasineura) species
Birds
Dippers (Cinclus)
Grey wagtail (Motacilla cinerea) and mountain wagtail (Motacilla clara)
A few swifts often nest behind waterfalls, including American black swift (Cypseloides niger), giant swiftlet (Hydrochous gigas), great dusky swift (Cypseloides senex) and white-collared swift (Streptoprocne zonaris)
Some waterfowl, including African black duck (Anas sparsa), blue duck (Hymenolaimus malacorhynchos), Brazilian merganser (Mergus octosetaceus), bronze-winged duck (Speculanas specularis), harlequin duck (Histrionicus histrionicus), Salvadori's teal (Salvadorina waigiuensis) and torrent duck (Merganetta armata)
Fish
A very large number of rheophilic fish species are known and include members of at least 419 genera in 60 families. Examples include:
Many species in the family Balitoridae, also known as the hill stream loaches.
Many species in the family Loricariidae from South and Central America
Many Chiloglanis species, which are freshwater catfish from Africa
The family Gyrinocheilidae.
Rheophilic cichlid genera/species:
The Lamena group in the genus Paretroplus from Madagascar.
Oxylapia polli from Madagascar.
Retroculus species from the Amazon Basin and rivers in the Guianas in South America.
Steatocranus species from the Congo River Basin in Africa.
Teleocichla species from the Amazon Basin in South America.
Teleogramma species from the Congo River Basin in Africa.
Mylesinus, Myleus, Ossubtus, Tometes and Utiaritichthys, which are serrasalmids from tropical South America
The Danube streber (Zingel streber), family Percidae.
Molluscs
Ancylus fluviatilis
Aylacostoma species
Lymnaea ovata
Amphibians
Neurergus strauchii, a newt from Turkey
Pach
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https://en.wikipedia.org/wiki/Decipherment%20of%20ancient%20Egyptian%20scripts
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The writing systems used in ancient Egypt were deciphered in the early nineteenth century through the work of several European scholars, especially Jean-François Champollion and Thomas Young. Ancient Egyptian forms of writing, which included the hieroglyphic, hieratic and demotic scripts, ceased to be understood in the fourth and fifth centuries AD, as the Coptic alphabet was increasingly used in their place. Later generations' knowledge of the older scripts was based on the work of Greek and Roman authors whose understanding was faulty. It was thus widely believed that Egyptian scripts were exclusively ideographic, representing ideas rather than sounds, and even that hieroglyphs were an esoteric, mystical script rather than a means of recording a spoken language. Some attempts at decipherment by Islamic and European scholars in the Middle Ages and early modern times acknowledged the script might have a phonetic component, but perception of hieroglyphs as purely ideographic hampered efforts to understand them as late as the eighteenth century.
The Rosetta Stone, discovered in 1799 by members of Napoleon Bonaparte's campaign in Egypt, bore a parallel text in hieroglyphic, demotic and Greek. It was hoped that the Egyptian text could be deciphered through its Greek translation, especially in combination with the evidence from the Coptic language, the last stage of the Egyptian language. Doing so proved difficult, despite halting progress made by Antoine-Isaac Silvestre de Sacy and Johan David Åkerblad. Young, building on their work, observed that demotic characters were derived from hieroglyphs and identified several of the phonetic signs in demotic. He also identified the meaning of many hieroglyphs, including phonetic glyphs in a cartouche containing the name of an Egyptian king of foreign origin, Ptolemy V. He was convinced, however, that phonetic hieroglyphs were used only in writing non-Egyptian words. In the early 1820s Champollion compared Ptolemy's cartouche w
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https://en.wikipedia.org/wiki/Discrimination%20testing
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Discrimination testing is a technique employed in sensory analysis to determine whether there is a detectable difference among two or more products. The test uses a group of assessors (panellists) with a degree of training appropriate to the complexity of the test to discriminate from one product to another through one of a variety of experimental designs. Though useful, these tests typically do not quantify or describe any differences, requiring a more specifically trained panel under different study design to describe differences and assess significance of the difference.
Statistical basis
The statistical principle behind any discrimination test should be to reject a null hypothesis (H0) that states there is no detectable difference between two (or more) products. If there is sufficient evidence to reject H0 in favor of the alternative hypothesis, HA: There is a detectable difference, then a difference can be recorded. However, failure to reject H0 should not be assumed to be sufficient evidence to accept it. H0 is formulated on the premise that all of the assessors guessed when they made their response. The statistical test chosen should give a probability value that the result was arrived at through pure guesswork. If this probability is sufficiently low (usually below 0.05 or 5%) then H0 can be rejected in favor of HA.
Tests used to decide whether or not to reject H0 include binomial, χ2 (Chi-squared), t-test etc.
Types of test
A number of tests can be classified as discrimination tests. If it's designed to detect a difference then it's a discrimination test. The type of test determines the number of samples presented to each member of the panel and also the question(s) they are asked to respond to.
Schematically, these tests may be described as follows; A & B are used for knowns, X and Y are used for different unknowns, while (AB) means that the order of presentation is unknown:
Paired comparison XY or (AB) – two unknown samples, known to be different, tes
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https://en.wikipedia.org/wiki/Book%20on%20Numbers%20and%20Computation
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The Book on Numbers and Computation (), or the Writings on Reckoning, is one of the earliest known Chinese mathematical treatises. It was written during the early Western Han dynasty, sometime between 202 BC and 186 BC. It was preserved among the Zhangjiashan Han bamboo texts and contains similar mathematical problems and principles found in the later Eastern Han period text of The Nine Chapters on the Mathematical Art.
Discovery
The text was found in tomb M247 of the burial grounds near Zhangjiashan, Jiangling County, in Hubei province, excavated in December–January 1983–1984. This tomb belonged to an anonymous civil servant in early West Han dynasty. In the tomb were 1200 bamboo strips written in ink. Originally the strips were bound together with string, but the string had rotted away and it took Chinese scholars 17 years to piece together the strips. As well as the mathematical work the strips covered government statutes, law reports and therapeutic gymnastics.
On the back of the sixth strip, the top has a black square mark, followed by the three characters 筭數書, which serve as the title of the rolled up book.
Content
The Suàn shù shū consists of 200 strips of bamboo written in ink, 180 strips are intact, the others have rotted. They consist of 69 mathematical problems from a variety of sources, two names Mr Wáng and Mr Yáng were found, probably two of the writers. Each problem has a question, an answer, followed by a method. The problems cover elementary arithmetic; fractions; inverse proportion; factorization of numbers; geometric progressions, in particular interest rate calculations and handling of errors; conversion between different units; the false position method for finding roots and the extraction of approximate square roots; calculation of the volume of various 3-dimensional shapes; relative dimensions of a square and its inscribed circle; calculation of unknown side of rectangle, given area and one side. All the calculations about circumference an
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https://en.wikipedia.org/wiki/Nucleon%20spin%20structure
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Nucleon spin structure describes the partonic structure of nucleon (proton and neutron) intrinsic angular momentum (spin). The key question is how the nucleon's spin, whose magnitude is 1/2ħ, is carried by its constituent partons (quarks and gluons). It was originally expected before the 1980s that quarks carry all of the nucleon spin, but later experiments contradict this expectation. In the late 1980s, the European Muon Collaboration (EMC) conducted experiments that suggested the spin carried by quarks is not sufficient to account for the total spin of the nucleons. This finding astonished particle physicists at that time, and the problem of where the missing spin lies is sometimes referred to as the proton spin crisis.
Experimental research on these topics has been continued by the Spin Muon Collaboration (SMC) and the COMPASS experiment at CERN, experiments E142, E143, E154 and E155 at SLAC, HERMES at DESY, experiments at JLab and RHIC, and others. Global analysis of data from all major experiments confirmed the original EMC discovery and showed that the quark spin did contribute about 30% to the total spin of the nucleon. A major topic of modern particle physics is to find the missing angular momentum, which is believed to be carried either by gluon spin, or by gluon and quark orbital angular momentum. This fact is expressed by the sum rule,
The gluon spin components are being measured by many experiments. Quark and gluon angular momenta will be studied by measuring so-called generalized parton distributions (GPD) through deeply virtual compton scattering (DVCS) experiments, conducted at CERN (COMPASS) and at Jefferson Lab, among other laboratories.
External links
Polarized colliders may prove to be the key in mapping out proton spin structure
Dr. Deshpande research webpage
Spin Muon Collaboration
HERMES
COMPASS
The Spin Structure of the Nucleon - Status and Recent Results
Standard Model
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https://en.wikipedia.org/wiki/Upper-atmospheric%20models
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Upper-atmospheric models are simulations of the Earth's atmosphere between 20 and 100 km (65,000 and 328,000 feet) that comprises the stratosphere, mesosphere, and the lower thermosphere. Whereas most climate models simulate a region of the Earth's atmosphere from the surface to the stratopause, there also exist numerical models which simulate the wind, temperature and composition of the Earth's tenuous upper atmosphere, from the mesosphere to the exosphere, including the ionosphere. This region is affected strongly by the 11 year Solar cycle through variations in solar UV/EUV/Xray radiation and solar wind leading to high latitude particle precipitation and aurora. It has been proposed that these phenomena may have an effect on the lower atmosphere, and should therefore be included in simulations of climate change. For this reason there has been a drive in recent years to create whole atmosphere models to investigate whether or not this is the case.
Jet stream perturbation model
A jet stream perturbation model is employed by Weather Logistics UK, which simulates the diversion of the air streams in the upper atmosphere. North Atlantic air flow modelling is simulated by combining a monthly jet stream climatology input calculated at 20 to 30°W, with different blocking high patterns. The jet stream input is generated by thermal wind balance calculations at 316mbars (6 to 9 km aloft) in the mid-latitude range from 40 to 60°N. Long term blocking patterns are determined by the weather forecaster, who identifies the likely position and strength of North Atlantic Highs from synoptic charts, the North Atlantic Oscillation (NAO) and El Niño-Southern Oscillation (ENSO) patterns. The model is based on the knowledge that low pressure systems at the surface are steered by the fast ribbons (jet streams) of air in the upper atmosphere. The jet stream - blocking interaction model simulation examines the sea surface temperature field using data from NOAA tracked along the ocean on a
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https://en.wikipedia.org/wiki/WYSIWYS
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In cryptography, What You See Is What You Sign (WYSIWYS) is a property of digital signature systems that ensures the semantic content of signed messages can not be changed, either by accident or intent.
Mechanism of WYSIWYS
When digitally signing a document, the integrity of the signature relies not just on the soundness of the digital signature algorithms that are used, but also on the security of the computing platform used to sign the document. The WYSIWYS property of digital signature systems aims to tackle this problem by defining a desirable property that the visual representation of a digital document should be consistent across computing systems, particularly at the points of digital signature and digital signature verification.
It is relatively easy to change the interpretation of a digital document by implementing changes on the computer system where the document is being processed, and the greater the semantic distance, the easier it gets. From a semantic perspective this creates uncertainty about what exactly has been signed. WYSIWYS is a property of a digital signature system that ensures that the semantic interpretation of a digitally signed message cannot be changed, either by accident or by intent. This property also ensures that a digital document to be signed can not contain hidden semantic content that can be revealed after the signature has been applied. Though a WYSIWYS implementation is only as secure as the computing platform it is running on, various methods have been proposed to make WYSIWYS more robust.
The term WYSIWYS was coined by Peter Landrock and Torben Pedersen to describe some of the principles in delivering secure and legally binding digital signatures for Pan-European projects.
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https://en.wikipedia.org/wiki/Ocean%20acoustic%20tomography
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Ocean acoustic tomography is a technique used to measure temperatures and currents over large regions of the ocean. On ocean basin scales, this technique is also known as acoustic thermometry. The technique relies on precisely measuring the time it takes sound signals to travel between two instruments, one an acoustic source and one a receiver, separated by ranges of . If the locations of the instruments are known precisely, the measurement of time-of-flight can be used to infer the speed of sound, averaged over the acoustic path. Changes in the speed of sound are primarily caused by changes in the temperature of the ocean, hence the measurement of the travel times is equivalent to a measurement of temperature. A change in temperature corresponds to about change in sound speed. An oceanographic experiment employing tomography typically uses several source-receiver pairs in a moored array that measures an area of ocean.
Motivation
Seawater is an electrical conductor, so the oceans are opaque to electromagnetic energy (e.g., light or radar). The oceans are fairly transparent to low-frequency acoustics, however. The oceans conduct sound very efficiently, particularly sound at low frequencies, i.e., less than a few hundred hertz. These properties motivated Walter Munk and Carl Wunsch to suggest "acoustic tomography" for ocean measurement in the late 1970s. The advantages of the acoustical approach to measuring temperature are twofold. First, large areas of the ocean's interior can be measured by remote sensing. Second, the technique naturally averages over the small scale fluctuations of temperature (i.e., noise) that dominate ocean variability.
From its beginning, the idea of observations of the ocean by acoustics was married to estimation of the ocean's state using modern numerical ocean models and the techniques assimilating data into numerical models. As the observational technique has matured, so too have the methods of data assimilation and th
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https://en.wikipedia.org/wiki/Leader%20%28spark%29
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In electromagnetism, a leader is a hot, highly conductive channel of plasma that plays a critical part during dielectric breakdown within a long electric spark.
Mechanism
When a gas is subjected to high voltage stress, the electric field is often quite non-uniform near one, or both, of the high voltage electrodes making up a spark gap. Breakdown initially begins with the formation of corona discharges near the electrode with the highest electrical stress. If the electrical field is further increased, longer length cold discharges (called streamers or burst corona) sporadically form near the stressed electrode. Streamers attract multiple electron avalanches into a single channel, propagating forward quickly via photon emission which leads to photoelectrons producing new avalanches. Streamers redistribute charge within the surrounding gas, temporarily forming regions of excess charge (space charges) in the regions surrounding the discharges.
If the electrical field is sufficiently high, the individual currents from multitudes of streamers combine to create a hot, highly conductive path that projects from the electrode, going some distance into the gap. The projecting channel of hot plasma is called a leader, and it can have an electrical conductivity approaching that of an electric arc. The leader effectively projects the electrical field from the nearby electrode further into the gap, similar to introducing a short length of wire into the gap. The tip of the conductive leader now forms a new region from which streamers can extend even further into the gap. As new streamer discharges feed the tip of the leader, the streamer currents help to keep the leader hot and conductive. Under sufficiently high voltages, the leader will continue to extend itself further into the gap, doing so in a series of jumps until the entire gap has been bridged. Although leaders are most often associated with the initial formative stages of a lightning stroke, they are characteristic of t
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https://en.wikipedia.org/wiki/VP/CSS
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VP/CSS was a time-sharing operating system developed by National CSS. It began life in 1968 as a copy of IBM's CP/CMS, which at the time was distributed to IBM customers at no charge, in source code form, without support, as part of the IBM Type-III Library. Through extensive in-house development, in what today would be termed a software fork, National CSS took VP/CSS in a different direction from CP/CMS. Although the two systems would eventually share many capabilities, their technical implementations diverged in substantive ways.
VP/CSS ran on IBM and IBM plug compatible hardware owned by NCSS (and by a few customers with site licenses, including Bank of America and Standard Oil of California). After an initial period running on the IBM System/360-67 platform used by CP/CMS, VP/CSS was ported to the System/370 series, made possible when IBM added virtual memory capabilities to the S/370 series in 1972.
VP/CSS was notable for supporting very large numbers of interactive users per machine, when compared with other IBM mainframe operating systems. Technical, operations, and commercial factors all played a role in making National CSS a commercially viable service business.
Architecture
VP/CSS shared the basic architecture and concepts of CP/CMS, which were revolutionary for their time. A control program (called CP in CP/CMS, VP in VP/CSS) created multiple independent virtual machines (VMs), implementing a full virtualization of the underlying hardware – meaning that each time-sharing user was provided with a private virtual machine. Each appeared to be an entire, stand-alone computer, capable of running any software that could run on the bare machine, including other operating systems. (This concept was pioneered with IBM's research system CP-40 in the first version of CP/CMS.)
This design was a departure from IBM's other monolithic operating systems. Isolating users from each other improved system stability: a bug in one user's software could not crash another u
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https://en.wikipedia.org/wiki/Rectangular%20potential%20barrier
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In quantum mechanics, the rectangular (or, at times, square) potential barrier is a standard one-dimensional problem that demonstrates the phenomena of wave-mechanical tunneling (also called "quantum tunneling") and wave-mechanical reflection. The problem consists of solving the one-dimensional time-independent Schrödinger equation for a particle encountering a rectangular potential energy barrier. It is usually assumed, as here, that a free particle impinges on the barrier from the left.
Although classically a particle behaving as a point mass would be reflected if its energy is less than a particle actually behaving as a matter wave has a non-zero probability of penetrating the barrier and continuing its travel as a wave on the other side. In classical wave-physics, this effect is known as evanescent wave coupling. The likelihood that the particle will pass through the barrier is given by the transmission coefficient, whereas the likelihood that it is reflected is given by the reflection coefficient. Schrödinger's wave-equation allows these coefficients to be calculated.
Calculation
The time-independent Schrödinger equation for the wave function reads
where is the Hamiltonian, is the (reduced)
Planck constant, is the mass, the energy of the particle and
is the barrier potential with height and width .
is the Heaviside step function, i.e.,
The barrier is positioned between and . The barrier can be shifted to any position without changing the results. The first term in the Hamiltonian, is the kinetic energy.
The barrier divides the space in three parts (). In any of these parts, the potential is constant, meaning that the particle is quasi-free, and the solution of the Schrödinger equation can be written as a superposition of left and right moving waves (see free particle). If
where the wave numbers are related to the energy via
The index on the coefficients and denotes the direction of the velocity vector. Note that, if the energy of the
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https://en.wikipedia.org/wiki/Fleming%E2%80%93Viot%20process
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In probability theory, a Fleming–Viot process (F–V process) is a member of a particular subset of probability measure-valued Markov processes on compact metric spaces, as defined in the 1979 paper by Wendell Helms Fleming and Michel Viot. Such processes are martingales and diffusions.
The Fleming–Viot processes have proved to be important to the development of a mathematical basis for the theories behind allele drift.
They are generalisations of the Wright–Fisher process and arise as infinite population limits of suitably rescaled variants of Moran processes.
See also
Coalescent theory
Voter model
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https://en.wikipedia.org/wiki/Palatal%20obturator
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A palatal obturator is a prosthesis that totally occludes an opening such as an oronasal fistula (in the roof of the mouth). They are similar to dental retainers, but without the front wire. Palatal obturators are typically short-term prosthetics used to close defects of the hard/soft palate that may affect speech production or cause nasal regurgitation during feeding. Following surgery, there may remain a residual orinasal opening on the palate, alveolar ridge, or vestibule of the larynx. A palatal obturator may be used to compensate for hypernasality and to aid in speech therapy targeting correction of compensatory articulation caused by the cleft palate. In simpler terms, a palatal obturator covers any fistulas (or "holes") in the roof of the mouth that lead to the nasal cavity, providing the wearer with a plastic/acrylic, removable roof of the mouth, which aids in speech, eating, and proper air flow.
Palatal obturators are not to be confused with palatal lifts or other prosthetic devices. A palatal obturator may be used in cases of a deficiency in tissue, when a remaining opening in the palate occurs. In some cases it may be downsized gradually so that tissue can strengthen over time and compensate for the decreasing size of the obturator. The palatal lift however, is used when there is not enough palatal movement. It raises the palate and reduces the range of movement necessary to provide adequate closure to separate the nasal cavity from the oral cavity. Speech bulbs and palatal lifts aid in velopharyngeal closure and do not obturate a fistula. A speech bulb, yet another type of prosthetic device often confused with a palatal obturator, contains a pharyngeal section, which goes behind the soft palate.
Palatal obturators are needed by individuals with cleft palate, those who have had tumors removed or have had traumatic injuries to their palate.
Types of palatal obturators
A palatal plate is a prosthetic device, generally consisting of an acrylic plate and
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https://en.wikipedia.org/wiki/Okorokov%20effect
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The Okorokov effect () or resonant coherent excitation, occurs when heavy ions move in crystals under channeling conditions. V. Okorokov predicted this effect in 1965 and it was first observed by Sheldon Datz in 1978.
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https://en.wikipedia.org/wiki/ISO%2031-10
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ISO 31-10 is the part of international standard ISO 31 that defines names and symbols for quantities and units related to nuclear reactions and ionizing radiations. It gives names and symbols for 70 quantities and units. Where appropriate, conversion factors are also given.
Its definitions include:
00031-10
Radioactivity quantities
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https://en.wikipedia.org/wiki/Global%20network%20positioning
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Global network positioning is a coordinates-based mechanism in a peer-to-peer network architecture which predicts Internet network distance (i.e. round-trip propagation and transmission delay). The mechanism is based on absolute coordinates computed from modeling the Internet as a geometric space. Since end hosts maintain their own coordinates, the approach allows end hosts to compute their inter-host distances as soon as they discover each other. Moreover, coordinates are very efficient in summarizing inter-host distances, making the approach very scalable.
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https://en.wikipedia.org/wiki/Medical%20terminology
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Medical terminology is a language used to precisely describe the human body including all its components, processes, conditions affecting it, and procedures performed upon it. Medical terminology is used in the field of medicine
Medical terminology has quite regular morphology, the same prefixes and suffixes are used to add meanings to different roots. The root of a term often refers to an organ, tissue, or condition. For example, in the disorder known as hypertension, the prefix "hyper-" means "high" or "over", and the root word "tension" refers to pressure, so the word "hypertension" refers to abnormally high blood pressure. The roots, prefixes and suffixes are often derived from Greek or Latin, and often quite dissimilar from their English-language variants. This regular morphology means that once a reasonable number of morphemes are learnt it becomes easy to understand very precise terms assembled from these morphemes. Much medical language is anatomical terminology, concerning itself with the names of various parts of the body.
Discussion
In forming or understanding a word root, one needs a basic comprehension of the terms and the source language. The study of the origin of words is called etymology. For example, if a word was to be formed to indicate a condition of kidneys, there are two primary roots – one from Greek (νεφρός nephr(os)) and one from Latin (ren(es)). Renal failure would be a condition of kidneys, and nephritis is also a condition, or inflammation, of the kidneys. The suffix -itis means inflammation, and the entire word conveys the meaning inflammation of the kidney. To continue using these terms, other combinations will be presented for the purpose of examples: The term supra-renal is a combination of the prefix supra- (meaning "above"), and the word root for kidney, and the entire word means "situated above the kidneys". The word "nephrologist" combines the root word for kidney to the suffix -ologist with the resultant meaning of "one who st
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https://en.wikipedia.org/wiki/Journal%20of%20Electronic%20Materials
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The Journal of Electronic Materials is a monthly peer-reviewed scientific journal that publishes studies, research, developments, and applications of materials that produce electronics. The editor-in-chief is Shadi Shahedipour-Sandvik, SUNY Polytechnic Institute.The IEEE/TMS Journal of Electronic Materials (JEM) is jointly sponsored by the IEEE Electron Devices Society and The Minerals, Metals and Materials Society. It is published by Springer on behalf of IEEE and TMS.
The journal also investigates the latest uses for semiconductors, magnetic alloys, dielectrics, nanoscale materials, and photonic materials. It also publishes methodologies for investigating the chemical properties, physical properties, and the electronic, and optical properties of these materials. Also, the specific materials science involves transistors, nanotechnology, electronic packaging, detectors, emitters, metallization, superconductivity, and energy applications.
Publishing formats include review papers and selected conference papers. Specialists and non-specialists, interested in this journal's topical coverage, are the target audience .
Abstracting and indexing services
According to the Journal Citation Reports, the Journal of Electronic Materials has a 2020 impact factor of 1.938.
The following databases provide indexing and abstracting services:
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https://en.wikipedia.org/wiki/Hydroxybenzotriazole
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Hydroxybenzotriazole (abbreviated HOBt) is an organic compound that is a derivative of benzotriazole. It is a white crystalline powder, which as a commercial product contains some water (~11.7% wt as the HOBt monohydrate crystal). Anhydrous HOBt is explosive.
It is mainly used to suppress the racemization of single-enantiomer chiral molecules and to improve the efficiency of peptide synthesis.
Use in peptide synthesis
Automated peptide synthesis involves the condensation of the amino group of protected amino acids with the activated ester. HOBt is used to produce such activated esters. These esters are insoluble (like the N-hydroxysuccinimide esters) and react with amines at ambient temperature to give amides.
HOBt is also used for the synthesis of amides from carboxylic acids aside from amino acids. These substrates may not be convertible to the acyl chlorides. For instance amide derivatives of ionophoric antibiotics have been prepared in this way.
Safety
Due to reclassification as UN0508, a class 1.3C explosive, hydroxybenzotriazole and its monohydrate crystal are no longer allowed to be transported by sea or air as per 49CFR (USDOT hazardous materials regulations). However, UNECE draft proposal ECE/TRANS/WP.15/AC.1/HAR/2009/1 has been circulated to UN delegates and, if implemented, would amend current regulations thus allowing for the monohydrate crystal to be shipped under the less-stringent code of UN3474 as a class 4.1 desensitized explosive.
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https://en.wikipedia.org/wiki/ARKive
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ARKive was a global initiative with the mission of "promoting the conservation of the world's threatened species, through the power of wildlife imagery", which it did by locating and gathering films, photographs and audio recordings of the world's species into a centralised digital archive. Its priority was the completion of audio-visual profiles for the c. 17,000 species on the IUCN Red List of Threatened Species.
The project was an initiative of Wildscreen, a UK-registered educational charity, based in Bristol. The technical platform was created by Hewlett-Packard, as part of the HP Labs' Digital Media Systems research programme.
ARKive had the backing of leading conservation organisations, including BirdLife International, Conservation International, International Union for Conservation of Nature (IUCN), the United Nations' World Conservation Monitoring Centre (UNEP-WCMC), and the World Wide Fund for Nature (WWF), as well as leading academic and research institutions, such as the Natural History Museum; Royal Botanic Gardens, Kew; and the Smithsonian Institution. It was a member of the Institutional Council of the Encyclopedia of Life.
Two ARKive layers for Google Earth, featuring endangered species and species in the Gulf of Mexico were produced by Google Earth Outreach. The first of these was launched in April 2008 by Wildscreen's Patron, Sir David Attenborough.
The website closed on 15 February 2019; its collection of images and videos remains securely stored for future generations.
History
The project formally was launched on 20 May 2003 by its patron, the UK-based natural history presenter, Sir David Attenborough, a long-standing colleague and friend of its chief instigator, the late Christopher Parsons, a former Head of the BBC Natural History Unit. Parsons never lived to see the fruition of the project, succumbing to cancer in November 2002 at the age of 70.
Parsons identified a need to provide a centralised safe haven for wildlife films and photogr
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https://en.wikipedia.org/wiki/Miles%20and%20Misra%20method
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The Miles and Misra Method (or surface viable count) is a technique used in Microbiology to determine the number of colony forming units in a bacterial suspension or homogenate.
The technique was first described in 1938 by Miles, Misra and Irwin who at the time were working at the LSHTM. The Miles and Misra method has been shown to be precise.
Materials
A calibrated dropping pipette, or automatic pipette, delivering drops of 20μl.
Petri dishes containing nutrient agar or other appropriate medium.
Phosphate Buffered Saline (PBS) or other appropriate diluent.
Bacterial suspension or homogenate.
Method
The inoculum / suspension is serially diluted by adding 1x of suspension to 9x of diluent. When the quantity of bacteria is unknown, dilutions should be made to at least 10−8.
Three plates are needed for each dilution series, for statistical reasons an average of at least 3 counts are needed.
The surface of the plates need to be sufficiently dry to allow a 20μl drop to be absorbed in 15–20 minutes.
Plates are divided into equal sectors (it is possible to use up to 8 per plate). The sectors are labelled with the dilutions.
In each sector, 1 x 20 μl of the appropriate dilution is dropped onto the surface of the agar and the drop allowed to spread naturally. In the original description of the method a drop from a height of 2.5 cm spread over an area of 1.5-2.0 cm. It is important to avoid touching the surface of the agar with the pipette.
The plates are left upright on the bench to dry before inversion and incubation at 37 °C for 18 – 24 hours (or appropriate incubation conditions considering the organism and agar used).
Each sector is observed for growth, high concentrations will give a confluent growth over the area of the drop, or a large number of small/merged colonies. Colonies are counted in the sector where the highest number of full-size discrete colonies can be seen (usually sectors containing between 2-20 colonies are counted).
The following equation is use
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https://en.wikipedia.org/wiki/Mix%20network
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Mix networks are routing protocols that create hard-to-trace communications by using a chain of proxy servers known as mixes which take in messages from multiple senders, shuffle them, and send them back out in random order to the next destination (possibly another mix node). This breaks the link between the source of the request and the destination, making it harder for eavesdroppers to trace end-to-end communications. Furthermore, mixes only know the node that it immediately received the message from, and the immediate destination to send the shuffled messages to, making the network resistant to malicious mix nodes.
Each message is encrypted to each proxy using public key cryptography; the resulting encryption is layered like a Russian doll (except that each "doll" is of the same size) with the message as the innermost layer. Each proxy server strips off its own layer of encryption to reveal where to send the message next. If all but one of the proxy servers are compromised by the tracer, untraceability can still be achieved against some weaker adversaries.
The concept of mix networks was first described by David Chaum in 1981. Applications that are based on this concept include anonymous remailers (such as Mixmaster), onion routing, garlic routing, and key-based routing (including Tor, I2P, and Freenet).
History
David Chaum published the concept of Mix Networks in 1979 in his paper: "Untraceable electronic mail, return addresses, and digital pseudonyms". The paper was for his master's degree thesis work, shortly after he was first introduced to the field of cryptography through the work of public key cryptography, Martin Hellman, Whitfield Diffie and Ralph Merkle. While public key cryptography encrypted the security of information, Chaum believed there to be personal privacy vulnerabilities in the meta data found in communications. Some vulnerabilities that enabled the compromise of personal privacy included time of messages sent and received, size of mes
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https://en.wikipedia.org/wiki/Haskins%20Laboratories
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Haskins Laboratories, Inc. is an independent 501(c) non-profit corporation, founded in 1935 and located in New Haven, Connecticut, since 1970. Haskins has formal affiliation agreements with both Yale University and the University of Connecticut; it remains fully independent, administratively and financially, of both Yale and UConn. Haskins is a multidisciplinary and international community of researchers that conducts basic research on spoken and written language. A guiding perspective of their research is to view speech and language as emerging from biological processes, including those of adaptation, response to stimuli, and conspecific interaction. Haskins Laboratories has a long history of technological and theoretical innovation, from creating systems of rules for speech synthesis and development of an early working prototype of a reading machine for the blind to developing the landmark concept of phonemic awareness as the critical preparation for learning to read an alphabetic writing system.
Research tools and facilities
Haskins Laboratories is equipped, in-house, with a comprehensive suite of tools and capabilities to advance its mission of research into language and literacy. As of 2014, these included:
Anechoic chamber
Electroencephalography
BioSemi 264 electrode, 24 bit Active Two System
EGI 128 electrode, Geodesic EEG System 300
Electromagnetic articulography (EMMA)
Carstens AG501
NDI WAVE
Eye tracking: HL is equipped with 3 SR Research eye-trackers.
2 Model Eyelink 1000 systems.
1 Model Eyelink 1000plus system.
Magnetic resonance imaging: Haskins has access to MRI scanners through agreements with the University of Connecticut and the Yale School of Medicine. On-site, HL has a Linux computer cluster dedicated to analysis of MRI data.
Motion capture: HL is equipped with a Vicon motion capture system with one Basler high-speed digital camera, six Vicon MX T-20 cameras and a Vicon MX Giganet for synching camera data and connecting cameras to t
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https://en.wikipedia.org/wiki/Duggan%E2%80%93Schwartz%20theorem
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The Duggan–Schwartz theorem (named after John Duggan and Thomas Schwartz) is a result about voting systems designed to choose a nonempty set of winners from the preferences of certain individuals, where each individual ranks all candidates in order of preference. It states that for three or more candidates, at least one of the following must hold:
The system is not anonymous (some voters are treated differently from others).
The system is imposed (some candidates can never win).
Every voter's top preference is in the set of winners.
The system can be manipulated by either an optimistic voter, one who can cast a ballot that would elect some candidate to a higher rank than all of those candidates who would have been elected if that voter had voted honestly; or by a pessimistic voter, one who can cast a ballot that would exclude some candidate to a lower rank than all of those candidates who were elected due that voter voting strategically.
The first two conditions are considered forbidden in any fair election, and the third condition requires many candidates to "tie" for the win. The general conclusion, then, is the same as that usually given to the Gibbard–Satterthwaite theorem: voting systems can be manipulated. The result essentially holds even if ties are allowed in the ballots; in that case, there exists at least one "weak dictator" such that at least one of the candidates tied at the top of that voter's ballot is a winner.
The Gibbard–Satterthwaite theorem is a similar theorem that deals with voting systems that elect a single winner. Likewise, Arrow's impossibility theorem deals with voting systems that yield a complete preference order of the candidates, rather than choosing only winners.
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https://en.wikipedia.org/wiki/MADI
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Multichannel Audio Digital Interface (MADI) standardized as AES10 by the Audio Engineering Society (AES) defines the data format and electrical characteristics of an interface that carries multiple channels of digital audio. The AES first documented the MADI standard in AES10-1991 and updated it in AES10-2003 and AES10-2008. The MADI standard includes a bit-level description and has features in common with the two-channel AES3 interface.
MADI supports serial digital transmission over coaxial cable or fibre-optic lines of 28, 56, 32, or 64 channels; and sampling rates to 96 kHz and beyond with an audio bit depth of up to 24 bits per channel. Like AES3 and ADAT Lightpipe, it is a unidirectional interface from one sender to one receiver.
Development and applications
MADI was developed by AMS Neve, Solid State Logic, Sony and Mitsubishi and is widely used in the audio industry, especially in the professional audio sector. It provides advantages over other audio digital interface protocols and standards such as AES3, ADAT Lightpipe, TDIF (Tascam Digital Interface), and S/PDIF (Sony/Philips Digital Interface). These advantages include:
Support for a greater number of channels per line
Use of coaxial and optical fiber media that support transmission of audio signals over 100 meters, up to 3000 meters over multi-mode and 40,000 meters over single-mode optical fiber
The original specification (AES10-1991) defined the MADI link as a 56-channel transport for linking large-format mixing consoles to digital multitrack recording devices. Large broadcast studios also adopted it for routing multi-channel audio throughout their facilities. The 2003 revision (AES10-2003) adds a 64-channel capability by removing varispeed operation and supports 96 kHz sampling frequency with reduced channel capacity. The latest AES10-2008 standard includes minor clarifications and updates to correspond to the current AES3 standard.
Audio over Ethernet of various types is the primary alternativ
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https://en.wikipedia.org/wiki/Proofing%20%28baking%20technique%29
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In cooking, proofing (also called proving) is a step in the preparation of yeast bread and other baked goods in which the dough is allowed to rest and rise a final time before baking. During this rest period, yeast ferments the dough and produces gases, thereby leavening the dough.
In contrast, proofing or blooming yeast (as opposed to proofing the dough) may refer to the process of first suspending yeast in warm water, a necessary hydration step when baking with active dry yeast. Proofing can also refer to the process of testing the viability of dry yeast by suspending it in warm water with carbohydrates (sugars). If the yeast is still alive, it will feed on the sugar and produce a visible layer of foam on the surface of the water mixture.
Fermentation rest periods are not always explicitly named, and can appear in recipes as "Allow dough to rise." When they are named, terms include "bulk fermentation", "first rise", "second rise", "final proof" and "shaped proof".
Dough processes
The process of making yeast-leavened bread involves a series of alternating work and rest periods. Work periods occur when the dough is manipulated by the baker. Some work periods are called mixing, kneading, and folding, as well as division, shaping, and panning. Work periods are typically followed by rest periods, which occur when dough is allowed to sit undisturbed. Particular rest periods include, but are not limited to, autolyse, bulk fermentation and proofing. Proofing, also sometimes called final fermentation, is the specific term for allowing dough to rise after it has been shaped and before it is baked.
Some breads begin mixing with an autolyse. This refers to a period of rest after the initial mixing of flour and water, a rest period that occurs sequentially before the addition of yeast, salt and other ingredients. This rest period allows for better absorption of water and helps the gluten and starches to align. The autolyse is credited to Raymond Calvel, who recommende
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https://en.wikipedia.org/wiki/Four-Phase%20Systems
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Four-Phase Systems was a computer company, founded by Lee Boysel and others, which built one of the earliest computers using semiconductor main memory and MOS LSI logic. The company was incorporated in February 1969 and had moderate commercial success. It was acquired by Motorola in 1981.
History
The idea behind Four-Phase Systems began when Boysel was designing MOS components at Fairchild Semiconductor in 1967. Boysel wrote a manifesto explaining how a computer could be built from a small number of MOS chips. Fairchild made Boysel head of a MOS design group, which he used to design parts satisfying the requirements of his putative computer. After doing this, Boysel left to start Four-Phase in October 1968, initially with two other engineers from his Fairchild group as well as others. Boysel was not sued by Fairchild, perhaps because of chaos caused by a change in Fairchild management at that time. When the company was incorporated in February 1969, he was joined by other engineers from the Fairchild group. Robert Noyce, co-founder of Intel, was an early board member.
Boysel arranged for chips to be fabricated by Cartesian, a wafer-processing company founded by another engineer from Fairchild. Four-Phase showed its system at the Fall Joint Computer Conference in 1970. By June 1971, Four-Phase IV/70 computers were in use at four different customers, and by March 1973, they had shipped 347 systems to 131 customers. The company enjoyed a substantial level of success, having revenues of $178 million by 1979.
In 1982, Four-Phase was sold to Motorola for a $253 million stock exchange (equivalent to $ today). The former location of the business on N De Anza Blvd is now Apple's Infinite Loop campus.
System
The Four-Phase CPU used a 24-bit word size. It fit on a single card and was composed of three AL1 chips, three read-only-memory (ROM) chips, and three random logic chips. A memory card used Four-Phase's 1K RAM chips. The system also included a built-in v
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https://en.wikipedia.org/wiki/Vehicular%20ad%20hoc%20network
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Vehicular ad hoc networks (VANETs) are created by applying the principles of mobile ad hoc networks (MANETs) – the spontaneous creation of a wireless network of mobile devices – to the domain of vehicles. VANETs were first mentioned and introduced in 2001 under "car-to-car ad-hoc mobile communication and networking" applications, where networks can be formed and information can be relayed among cars. It was shown that vehicle-to-vehicle and vehicle-to-roadside communications architectures will co-exist in VANETs to provide road safety, navigation, and other roadside services.
VANETs are a key part of the intelligent transportation systems (ITS) framework. Sometimes, VANETs are referred as Intelligent Transportation Networks. They are understood as having evolved into a broader "Internet of vehicles". which itself is expected to ultimately evolve into an "Internet of autonomous vehicles".
While, in the early 2000s, VANETs were seen as a mere one-to-one application of MANET principles, they have since then developed into a field of research in their own right. By 2015, the term VANET became mostly synonymous with the more generic term inter-vehicle communication (IVC), although the focus remains on the aspect of spontaneous networking, much less on the use of infrastructure like Road Side Units (RSUs) or cellular networks.
Applications
VANETs support a wide range of applications – from simple one hop information dissemination of, e.g., cooperative awareness messages (CAMs) to multi-hop dissemination of messages over vast distances.
Most of the concerns of interest to mobile ad hoc networks (MANETs) are of interest in VANETs, but the details differ. Rather than moving at random, vehicles tend to move in an organized fashion. The interactions with roadside equipment can likewise be characterized fairly accurately. And finally, most vehicles are restricted in their range of motion, for example by being constrained to follow a paved highway.
Example applications of V
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https://en.wikipedia.org/wiki/VerilogCSP
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In integrated circuit design, VerilogCSP is a set of macros added to Verilog HDL to support Communicating Sequential Processes (CSP) channel communications. These macros are intended to be used in designing digital asynchronous circuits.
VerilogCSP also describes nonlinear pipelines and high-level channel timing properties, such as forward and backward latencies, minimum cycle time, and slack.
External links
VerilogCSP Homepage
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https://en.wikipedia.org/wiki/Geodesics%20as%20Hamiltonian%20flows
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In mathematics, the geodesic equations are second-order non-linear differential equations, and are commonly presented in the form of Euler–Lagrange equations of motion. However, they can also be presented as a set of coupled first-order equations, in the form of Hamilton's equations. This latter formulation is developed in this article.
Overview
It is frequently said that geodesics are "straight lines in curved space". By using the Hamilton–Jacobi approach to the geodesic equation, this statement can be given a very intuitive meaning: geodesics describe the motions of particles that are not experiencing any forces. In flat space, it is well known that a particle moving in a straight line will continue to move in a straight line if it experiences no external forces; this is Newton's first law. The Hamiltonian describing such motion is well known to be with p being the momentum. It is the conservation of momentum that leads to the straight motion of a particle. On a curved surface, exactly the same ideas are at play, except that, in order to measure distances correctly, one must use the Riemannian metric. To measure momenta correctly, one must use the inverse of the metric. The motion of a free particle on a curved surface still has exactly the same form as above, i.e. consisting entirely of a kinetic term. The resulting motion is still, in a sense, a "straight line", which is why it is sometimes said that geodesics are "straight lines in curved space". This idea is developed in greater detail below.
Geodesics as an application of the principle of least action
Given a (pseudo-)Riemannian manifold M, a geodesic may be defined as the curve that results from the application of the principle of least action. A differential equation describing their shape may be derived, using variational principles, by minimizing (or finding the extremum) of the energy of a curve. Given a smooth curve
that maps an interval I of the real number line to the manifold M, one writes the
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https://en.wikipedia.org/wiki/Thomas%20Jech
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Thomas J. Jech (, ; born January 29, 1944, in Prague) is a mathematician specializing in set theory who was at Penn State for more than 25 years.
Life
He was educated at Charles University (his advisor was Petr Vopěnka) and from 2000 is at the Institute of Mathematics of the Academy of Sciences of the Czech Republic.
Work
Jech's research also includes mathematical logic, algebra, analysis, topology, and measure theory.
Jech gave the first published proof of the consistency of the existence of a Suslin line.
With Karel Prikry, he introduced the notion of precipitous ideal. He gave several models where the axiom of choice failed, for example one with ω1 measurable. The concept of a Jech–Kunen tree is named after him and Kenneth Kunen.
Bibliography
Lectures in set theory, with particular emphasis on the method of forcing, Springer-Verlag Lecture Notes in Mathematics 217 (1971) ()
The axiom of choice, North-Holland 1973 (Dover paperback edition )
(with K. Hrbáček) Introduction to set theory, Marcel Dekker, 3rd edition 1999 ()
Multiple forcing, Cambridge University Press 1986 ()
Set Theory: The Third Millennium Edition, revised and expanded, 2006, Springer Science & Business Media, . 1st ed. 1978; 2nd (corrected) ed. 1997
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https://en.wikipedia.org/wiki/Villin-1
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Villin-1 is a 92.5 kDa tissue-specific actin-binding protein associated with the actin core bundle of the brush border. Villin-1 is encoded by the VIL1 gene. Villin-1 contains multiple gelsolin-like domains capped by a small (8.5 kDa) "headpiece" at the C-terminus consisting of a fast and independently folding three-helix bundle that is stabilized by hydrophobic interactions. The headpiece domain is a commonly studied protein in molecular dynamics due to its small size and fast folding kinetics and short primary sequence.
Structure
Villin-1 is made up of seven domains, six homologous domains make up the N-terminal core and the remaining domain makes up the C-terminal cap. Villin contains three phosphatidylinositol 4,5-biphosphate (PIP2) binding sites, one of which is located at the head piece and the other two in the core. The core domain is approximately 150 amino acid residues grouped in six repeats. On this core is an 87 residue, hydrophobic, C-terminal headpiece
The headpiece (HP67) is made up of a compact, 70 amino acid folded protein at the C-terminus. This headpiece contains an F-actin binding domain. Residues K38, E39, K65, 70-73:KKEK, G74, L75 and F76 surround a hydrophobic core and are believed to be involved in the binding of F-actin to villin-1. Residues E39 and K70 form a salt bridge buried within the headpiece which serves to connect N and C terminals. This salt bridge may also orient and fix the C-terminal residues involved in F-actin binding as in the absence of this salt bridge no binding occurs. A hydrophobic “cap” is formed by residue W64 side chains, which is completely conserved throughout the villin family. Below this cap is a crown of alternative positive and negative charged localities.
Villin can undergo post-translational modifications like tyrosine phosphorylation. Villin-1 has the ability to dimerize and the dimerization site is located at the amino end of the protein.
Expression
Villin-1 is an actin binding protein expressed
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https://en.wikipedia.org/wiki/Rop%20protein
|
Rop (also known as repressor of primer, or as RNA one modulator (ROM)) is a small dimeric protein responsible for keeping the copy number of ColE1 family and related bacterial plasmids low in E. coli by increasing the speed of pairing between the preprimer RNA, RNA II, and its antisense RNA, RNA I. Structurally, Rop is a homodimeric four-helix bundle protein formed by the antiparallel interaction of two helix-turn-helix monomers. The Rop protein's structure has been solved to high resolution. Due to its small size and known structure, Rop has been used in protein design work to rearrange its helical topology and reengineer its loop regions. In general, the four-helix bundle has been extensively used in de novo protein design work as a simple model to understand the relationship between amino acid sequence and structure.
External links
Rop protein from Proteopedia
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https://en.wikipedia.org/wiki/Richard%20Sears%20McCulloh
|
Richard Sears McCulloh (18 March 1818 – 1894) was an American civil engineer and professor of mechanics and thermodynamics at the Washington and Lee University, Lexington, Virginia.
Career
McCulloh was born on 18 March 1818 in Baltimore, Maryland, United States.
He graduated from the College of New Jersey in 1836, then studied chemistry in Philadelphia with James Curtis Booth from 1838 to 1839.
From 1846 to 1849 he worked for the U.S. Mint in Philadelphia.
He was elected to the American Philosophical Society in 1846. McCulloh was appointed professor of natural philosophy at Princeton University on 24 October 1849, and then professor of natural and experimental philosophy at Columbia College on 3 April 1854.
During the American Civil War, McCulloh disappeared from New York after the draft riots and in October 1863 McCulloh went to Richmond, Virginia to become the consulting chemist of the Confederate Nitre and Mining Bureau.
In response, Columbia College expelled him from his professorship.
While in Richmond, he helped "the Confederacy in making a chemical weapon".
His experiments in creating a lethal gas were proved successful in February 1865, but before the weapon could be used in practice Richmond fell in April 1865. McCulloh fled the city but was captured two months later off the coast of Florida, and for almost two years was imprisoned in the Virginia State Penitentiary.
After being released, in 1866 McCulloh was appointed to the new "McCormick Professorship of Experimental Philosophy & Applied Mathematics" at Washington and Lee College.
He resigned later during financial retrenchment.
In 1869 he was a member of a faculty committee that created an expensive plan for expanding the Washington College curriculum dramatically.
In January 1870 he was a Professor of Natural Philosophy at Washington College.
In 1878, McCulloh received an honorary doctorate of law degree from Washington and Lee University.
Work
McCulloh was interested in a range of practical and
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https://en.wikipedia.org/wiki/Wolong%20National%20Nature%20Reserve
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Wolong National Nature Reserve (), also officially known as Wolong Special Administrative Region (), is a protected area located in Wenchuan County, Sichuan Province, People's Republic of China.
Established in 1963 with an initial size of about 20,000 hectares, the reserve was further expanded in 1975, covering an area of about 200,000 hectares in the Qionglai Mountains region. There are over 4,000 different species recorded in the reserve. According to China's Third National Giant Panda Survey, Wolong National Nature Reserve houses about 150 wild giant pandas. The reserve is also a home to many other endangered species including: snow leopards, red pandas, golden monkeys, white-lipped deer and many precious plants. Before the devastating 2008 Wenchuan earthquake Wolong received up to 200,000 visitors every year.
As one of the Sichuan Giant Panda Sanctuaries, Wolong National Nature Reserve has been a UNESCO World Heritage Site since 2006.
Background
In June 1980, the Chinese government started its cooperation with the World Wide Fund for Nature and the "China Conservation and Research Center for the Giant Panda" (CCRCGP) was established to ensure a future for the giant pandas. The aim was to increase the number of pandas in captive-breeding programs, however with the ultimate goal to return a larger number of pandas to their original, natural habitats. When the cooperation started giant pandas were still listed as an endangered species by the IUCN.
In 2016, the IUCN reclassified the giant panda from being "endangered" to the new classification "vulnerable", affirming decade-long efforts to save the panda.
Location
A mountain stream runs through the Wolong Valley (where the reserve is); the stream is heavily armoured with boulders and smaller rounded stones. Stream waters are rather alkaline with pH levels in the range of 8.91. (Hogan, 2007) Water quality turbidity is quite high due to extensive sand and gravel mining in stream.
According to a 2001 researc
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https://en.wikipedia.org/wiki/Interleukin%20receptor
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Interleukin receptors are a family of cytokine receptors for interleukins. They belong to the immunoglobulin superfamily.
Types
There are two main families of Interleukin receptors, Type 1 and Type 2.
Type 1
Type 1 interleukin receptors include:
Interleukin-1 receptor
Interleukin-2 receptor
Interleukin-3 receptor
Interleukin-4 receptor
Interleukin-5 receptor
Interleukin-6 receptor
Interleukin-7 receptor
Interleukin-9 receptor
Interleukin-11 receptor
Interleukin-12 receptor
Interleukin-13 receptor
Interleukin-15 receptor
Interleukin-18 receptor
Interleukin-21 receptor
Interleukin-23 receptor
Interleukin-27 receptor
Type 2
Type 2 interleukin receptors are Type II cytokine receptors. They include:
Interleukin-10 receptor
Interleukin-20 receptor
Interleukin-22 receptor
Interleukin-28 receptor
Other
Interleukin-8 receptor, RANTES receptors (CCR1, CCR3, CCR5), MIP-1 receptor, PF4 receptor, M-CSF receptor and NAP-2 receptor belong to GPCR chemokine receptor family.
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https://en.wikipedia.org/wiki/TNF%20receptor%20superfamily
|
The tumor necrosis factor receptor superfamily (TNFRSF) is a protein superfamily of cytokine receptors characterized by the ability to bind tumor necrosis factors (TNFs) via an extracellular cysteine-rich domain. With the exception of nerve growth factor (NGF), all TNFs are homologous to the archetypal TNF-alpha. In their active form, the majority of TNF receptors form trimeric complexes in the plasma membrane. Accordingly, most TNF receptors contain transmembrane domains (TMDs), although some can be cleaved into soluble forms (e.g. TNFR1), and some lack a TMD entirely (e.g. DcR3). In addition, most TNF receptors require specific adaptor protein such as TRADD, TRAF, RIP and FADD for downstream signalling. TNF receptors are primarily involved in apoptosis and inflammation, but they can also take part in other signal transduction pathways, such as proliferation, survival, and differentiation. TNF receptors are expressed in a wide variety of tissues in mammals, especially in leukocytes.
The term death receptor refers to those members of the TNF receptor superfamily that contain a death domain, such as TNFR1, Fas receptor, DR4 and DR5. They were named after the fact that they seemed to play an important role in apoptosis (programmed cell death), although they are now known to play other roles as well.
In the strict sense, the term TNF receptor is often used to refer to the archetypal members of the superfamily, namely TNFR1 and TNFR2, which recognize TNF-alpha.
Members
There are 27 family members, numerically classified as TNFRSF#, where # denotes the member number, sometimes followed a letter.
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https://en.wikipedia.org/wiki/Scaffold%20%28programming%29
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Scaffolding, as used in computing, refers to one of two techniques:
Code generation:
It is a technique related to database access in some model–view–controller frameworks.
Project generation:
It is a technique supported by various programming tools.
Code generation
Scaffolding is a technique supported by some model–view–controller frameworks, in which the programmer can specify how the application database may be used. The compiler or framework uses this specification, together with pre-defined code templates, to generate the final code that the application can use to create, read, update and delete database entries, effectively treating the templates as a "scaffold" on which to build a more powerful application.
Scaffolding is an evolution of database code generators from earlier development environments, such as Oracle's CASE Generator, and many other 4GL client-server software development products.
Scaffolding was made popular by the Ruby on Rails framework. It has been adapted to other software frameworks, including OutSystems Platform, Express Framework, Blitz.js, Play framework, Django, web2py, MonoRail, Brail, Symfony, Laravel, CodeIgniter, Yii, CakePHP, Phalcon PHP, Model-Glue, PRADO, Grails, Catalyst, Mojolicious, Seam Framework, Spring Roo, JHipster, ASP.NET Dynamic Data, KumbiaPHP and ASP.NET MVC framework's Metadata Template Helpers.
Run-time vs. design-time scaffolding
Scaffolding can occur at two different phases of the program lifecycle: design time and run time. Design time scaffolding produces files of code that can later be modified by the programmer to customize the way the application database is used. However, for large-scale applications this approach may be difficult to maintain due to the sheer number of files produced, and the fact that the design of the files was largely fixed when they were generated or copied from the original templates. Alternatively, run time scaffolding produces code on the fly. It allows changes to the design o
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https://en.wikipedia.org/wiki/Departure%20function
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In thermodynamics, a departure function is defined for any thermodynamic property as the difference between the property as computed for an ideal gas and the property of the species as it exists in the real world, for a specified temperature T and pressure P. Common departure functions include those for enthalpy, entropy, and internal energy.
Departure functions are used to calculate real fluid extensive properties (i.e. properties which are computed as a difference between two states). A departure function gives the difference between the real state, at a finite volume or non-zero pressure and temperature, and the ideal state, usually at zero pressure or infinite volume and temperature.
For example, to evaluate enthalpy change between two points h(v1,T1) and h(v2,T2) we first compute the enthalpy departure function between volume v1 and infinite volume at T = T1, then add to that the ideal gas enthalpy change due to the temperature change from T1 to T2, then subtract the departure function value between v2 and infinite volume.
Departure functions are computed by integrating a function which depends on an equation of state and its derivative.
General expressions
General expressions for the enthalpy H, entropy S and Gibbs free energy G are given by
Departure functions for Peng–Robinson equation of state
The Peng–Robinson equation of state relates the three interdependent state properties pressure P, temperature T, and molar volume Vm. From the state properties (P, Vm, T), one may compute the departure function for enthalpy per mole (denoted h) and entropy per mole (s):
where is defined in the Peng-Robinson equation of state, Tr is the reduced temperature, Pr is the reduced pressure, Z is the compressibility factor, and
Typically, one knows two of the three state properties (P, Vm, T), and must compute the third directly from the equation of state under consideration. To calculate the third state property, it is necessary to know three constants for the
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https://en.wikipedia.org/wiki/Defensive%20computing
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Defensive computing is a form of practice for computer users to help reduce the risk of computing problems, by avoiding dangerous computing practices. The primary goal of this method of computing is to be able to anticipate and prepare for potentially problematic situations prior to their occurrence, despite any adverse conditions of a computer system or any mistakes made by other users. This can be achieved through adherence to a variety of general guidelines, as well as the practice of specific computing techniques.
Strategies for defensive computing could be divided into two categories, network security and the backup and restoration of data.
Network security
Users put their computers at risk when accessing the Internet and other networks. The use of either of these allows others to gain access to a user's system and important information. By implementing certain strategies, defensive users aim to reduce the risk associated with network access.
Firewall
A firewall is a collection of security measures that protects a computer from harmful inbound and outbound traffic on the Internet and prevents the unauthorized access of computer systems. These security measures are integrated into the form of special software that runs autonomously either on individual computer systems, or externally through built in software within routers and modems.
Not all firewall software will protect computers from sending unauthorized or harmful outbound traffic.
An important defensive computing strategy is to seek and implement quality firewall software that filters both inbound and outbound traffic.
Anti-malware software
A basic strategy for all defensive computer users is to install and use anti-malware software.
Firewalls may not completely protect a computer. Malicious software may be able to get through a firewall and onto a system. Anti-Malware such as anti-virus, anti-phishing and email filtering software offer some protection against harmful software that reside within a
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https://en.wikipedia.org/wiki/Faug%C3%A8re%27s%20F4%20and%20F5%20algorithms
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In computer algebra, the Faugère F4 algorithm, by Jean-Charles Faugère, computes the Gröbner basis of an ideal of a multivariate polynomial ring. The algorithm uses the same mathematical principles as the Buchberger algorithm, but computes many normal forms in one go by forming a generally sparse matrix and using fast linear algebra to do the reductions in parallel.
The Faugère F5 algorithm first calculates the Gröbner basis of a pair of generator polynomials of the ideal. Then it uses this basis to reduce the size of the initial matrices of generators for the next larger basis:
If Gprev is an already computed Gröbner basis (f2, …, fm) and we want to compute a Gröbner basis of (f1) + Gprev then we will construct matrices whose rows are m f1 such that m is a monomial not divisible by the leading term of an element of Gprev.
This strategy allows the algorithm to apply two new criteria based on what Faugère calls signatures of polynomials. Thanks to these criteria, the algorithm can compute Gröbner bases for a large class of interesting polynomial systems, called regular sequences, without ever simplifying a single polynomial to zero—the most time-consuming operation in algorithms that compute Gröbner bases. It is also very effective for a large number of non-regular sequences.
Implementations
The Faugère F4 algorithm is implemented
in FGb, Faugère's own implementation, which includes interfaces for using it from C/C++ or Maple,
in Maple computer algebra system, as the option method=fgb of function Groebner[gbasis]
in the Magma computer algebra system,
in the SageMath computer algebra system,
Study versions of the Faugère F5 algorithm is implemented in
the SINGULAR computer algebra system;
the SageMath computer algebra system.
in SymPy Python package.
Applications
The previously intractable "cyclic 10" problem was solved by F5, as were a number of systems related to cryptography; for example HFE and C*.
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https://en.wikipedia.org/wiki/New%20Zealand%20torpedo
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Tetronarce fairchildi, commonly known as the New Zealand torpedo, is a species of electric ray of the family Torpedinidae found only around New Zealand, at depths of between 5 and 1,100 m. This species is placed in the genus Tetronarce.
In June 2018 the New Zealand Department of Conservation classified the T. fairchildi as "Data Deficient" under the New Zealand Threat Classification System.
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https://en.wikipedia.org/wiki/Provider%20model
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The provider model is a design pattern formulated by Microsoft for use in the ASP.NET Starter Kits and formalized in .NET version 2.0. It is used to allow an application to choose from one of multiple implementations or "condiments" in the application configuration, for example, to provide access to different data stores to retrieve login information, or to use different storage methodologies such as a database, binary to disk, XML, etc.
The .NET extensible provider model allows a "component" to have multiple implementations using an abstract factory pattern approach. Providers are a subclass of the ProviderBase class and typically instantiated using a factory method.
The provider model in ASP.NET 2.0 provides extensibility points for developers to plug their own implementation of a feature into the runtime. Both the membership and role features in ASP.NET 2.0 follow the provider pattern by specifying an interface, or contract. The provider model begins with the abstract class ProviderBase. ProviderBase exists to enforce the contract that all providers need public Name and Description properties, as well as a public Initialize method. Inheriting from ProviderBase are the MembershipProvider and RoleProvider abstract classes. These classes add additional properties and methods to define the interface for their specific areas of functionality.
Strategy pattern renaming
It has been argued that the provider model is merely another name for the already existing strategy pattern, and that this should, therefore, be the preferred terminology for describing the design pattern at hand.
See also
Strategy pattern
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https://en.wikipedia.org/wiki/Nuclear%20graphite
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Nuclear graphite is any grade of graphite, usually synthetic graphite, manufactured for use as a moderator or reflector within a nuclear reactor. Graphite is an important material for the construction of both historical and modern nuclear reactors, due to its extreme purity and ability to withstand extremely high temperature.
History
Nuclear fission, the creation of a nuclear chain reaction in uranium, was discovered in 1939 following experiments by Otto Hahn and Fritz Strassman, and the interpretation of their results by physicists such as Lise Meitner and Otto Frisch. Shortly thereafter, word of the discovery spread throughout the international physics community.
In order for the fission process to chain react, the neutrons created by uranium fission must be slowed down by interacting with a neutron moderator (an element with a low atomic weight, that will "bounce", when hit by a neutron) before they will be captured by other uranium atoms. By late 1939, it became well known that the two most promising moderators were heavy water and graphite.
In February 1940, using funds that were allocated partly as a result of the Einstein-Szilard letter to President Roosevelt, Leo Szilard purchased several tons of graphite from the Speer Carbon Company and from the National Carbon Company (the National Carbon Division of the Union Carbide and Carbon Corporation in Cleveland, Ohio) for use in Enrico Fermi's first fission experiments, the so-called exponential pile. Fermi writes that "The results of this experiment was [sic] somewhat discouraging" presumably due to the absorption of neutrons by some unknown impurity. So, in December 1940 Fermi and Szilard met with Herbert G. MacPherson and V. C. Hamister at National Carbon to discuss the possible existence of impurities in graphite. During this conversation it became clear that minute quantities of boron impurities were the source of the problem.
As a result of this meeting, over the next two years, MacPherson and Hamiste
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https://en.wikipedia.org/wiki/Janos%20Galambos
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Janos Galambos (Galambos János in Hungarian, 1 September 1940 – 19 December 2019) was a Hungarian mathematician affiliated with Temple University in Philadelphia, Pennsylvania, USA.
Education and career
Galambos earned his Ph.D. in 1963 from Eötvös Loránd University, under the supervision of Alfréd Rényi. He remained at the Eötvös Loránd University as an assistant professor from 1964 to 1965. He was lecturer at the University of Ghana from 1965 to 1969 and at University of Ibadan from 1969 to 1970. In 1970, Galambos joined the faculty of Temple University in Philadelphia and remained there until his retirement in 2012.
Galambos worked on probability theory, number theory, order statistics, and many other sub-specialties, and published hundreds of papers and many books.
In 1993 he was elected external member of the Hungarian Academy of Sciences, and in 2001 he became a corresponding member of the Royal Academy of Engineering of Spain.
Selected books
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https://en.wikipedia.org/wiki/SNePS
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SNePS is a knowledge representation, reasoning, and acting (KRRA) system developed and maintained by Stuart C. Shapiro and colleagues at the State University of New York at Buffalo.
SNePS is simultaneously a logic-based, frame-based, and network-based KRRA system. It uses an assertional model of knowledge, in that a SNePS knowledge base (KB) consists of a set of assertions (propositions) about various entities. Its intended model is of an intensional domain of mental entities—the entities conceived of by some agent, and the propositions believed by it. The intensionality is primarily accomplished by the absence of a built-in equality operator, since any two syntactically different terms might have slightly different Fregean senses.
SNePS has three styles of inference: formula-based, derived from its logic-based personality; slot-based, derived from its frame-based personality; and path-based, derived from its network-based personality. However, all three are integrated, operating together.
SNePS may be used as a stand-alone KRR system. It has also been used, along with its integrated acting component, to implement the mind of intelligent agents (cognitive robots), in accord with the GLAIR agent architecture (a layered cognitive architecture). The SNePS Research Group often calls its agents Cassie.
SNePS as a Logic-Based System
As a logic-based system, a SNePS KB consists of a set of terms, and functions and formulas over those terms. The set of logical connectives and quantifiers extends the usual set used by first-order logics, all taking one or more arbitrarily-sized sets of arguments. In accord with the intended use of SNePS to represent the mind of a natural-language-competent intelligent agent, propositions are first-class entities of the intended domain, so formulas are actually proposition-denoting functional terms. SNePSLOG, the input-output language of the logic-based face of SNePS, looks like a naive logic in that function symbols (including "pre
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https://en.wikipedia.org/wiki/The%20Ruins%20%28novel%29
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The Ruins is a 2006 horror novel by American author Scott Smith, set on Mexico's Yucatan Peninsula. The book fits specifically into the survival horror genre, which is marked by people doing whatever it takes to conquer their environment and stay alive. The novel was released on July 18, 2006 ().
A film adaptation of the novel was released in the United States and Canada on April 4, 2008.
Plot summary
Four American tourists — Eric, his girlfriend Stacy, her best friend and former roommate Amy, and Amy's boyfriend Jeff, a medical student — are vacationing in Mexico. They befriend a German tourist named Mathias, and a trio of Greeks who go by the Spanish nicknames Pablo, Juan, and Don Quixote. Jeff volunteers the group to accompany Mathias as he attempts to find his brother Henrich, who went missing after having followed a girl he'd met to an archaeological dig. As they leave the hotel, Pablo joins them, leaving a note and a map for Juan and Don Quixote.
The six of them head down to the rural Yucatan in search of Henrich. The driver of the pickup truck who takes them to the outskirts of Coba tells Amy that the place to which they are going is "not good," and offers to drive the group somewhere else. Amy does not quite get the message and leaves anyway. Near a Mayan village, they discover a disguised trail which leads to a large hill covered in vines and surrounded by bare earth. The group approach the hill, and are confronted by armed men from the village. Jeff attempts to communicate with them in Spanish, but they do not respond. After Amy steps on the vine-covered hill when attempting to take a picture of the entire group, the men force the group to stay on the vine-covered hill.
At the top of the hill is an abandoned campsite with tents, and a makeshift windlass and rope leading down a mine shaft. Much of the camp is overgrown with the same vines that cover the hill. Believing they may be able to escape down the far side of the hill, Jeff and Mathias go down
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https://en.wikipedia.org/wiki/Kelvin%20equation
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The Kelvin equation describes the change in vapour pressure due to a curved liquid–vapor interface, such as the surface of a droplet. The vapor pressure at a convex curved surface is higher than that at a flat surface. The Kelvin equation is dependent upon thermodynamic principles and does not allude to special properties of materials. It is also used for determination of pore size distribution of a porous medium using adsorption porosimetry. The equation is named in honor of William Thomson, also known as Lord Kelvin.
Formulation
The original form of the Kelvin equation, published in 1871, is:
where:
= vapor pressure at a curved interface of radius
= vapor pressure at flat interface () =
= surface tension
= density of vapor
= density of liquid
, = radii of curvature along the principal sections of the curved interface.
This may be written in the following form, known as the Ostwald–Freundlich equation:
where is the actual vapour pressure,
is the saturated vapour pressure when the surface is flat,
is the liquid/vapor surface tension, is the molar volume of the liquid, is the universal gas constant, is the radius of the droplet, and is temperature.
Equilibrium vapor pressure depends on droplet size.
If the curvature is convex, is positive, then
If the curvature is concave, is negative, then
As increases, decreases towards , and the droplets grow into bulk liquid.
If the vapour is cooled, then decreases, but so does . This means increases as the liquid is cooled. and may be treated as approximately fixed, which means that the critical radius must also decrease.
The further a vapour is supercooled, the smaller the critical radius becomes. Ultimately it can become as small as a few molecules, and the liquid undergoes homogeneous nucleation and growth.
The change in vapor pressure can be attributed to changes in the Laplace pressure. When the Laplace pressure rises in a droplet, the droplet tends to evaporate more easily.
When a
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https://en.wikipedia.org/wiki/Tetrafluorohydrazine
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Tetrafluorohydrazine or perfluorohydrazine, , is a colourless, nonflammable, reactive inorganic gas. It is a fluorinated analog of hydrazine.
Tetrafluorohydrazine is manufactured from nitrogen trifluoride using an iron catalyst or iron(II) fluoride.
Properties
Tetrafluorohydrazine is in equilibrium with its radical monomer nitrogen difluoride.
At room temperature is mostly associated with only 0.7% in the form of at 5mm Hg pressure. When the temperature rises to 225 °C, it mostly dissociates with 99% in the form of .
The energy needed to break the N-N bond in is 20.8 kcal/mol, with an entropy change of 38.6 eu. For comparison, the dissociation energy of the N-N bond is 14.6 kcal/mol in , 10.2 kcal/mol in , and 60 kcal/mol in . The enthalpy of formation of (ΔHf) is 34.421 kJ/mol.
Uses
Tetrafluorohydrazine is used in some chemical syntheses, as a precursor or a catalyst. It was considered for use as a high-energy liquid oxidizer in some never-flown rocket fuel formulas in 1959. Tetrafluorohydrazine is used in organic synthesis and as an oxidizing agent for rocket fuels.
Safety
Tetrafluorohydrazine is a highly hazardous chemical that explodes in the presence of organic materials.
It is a toxic chemical which irritates skin, eyes and lungs. It is a neurotoxin and may cause methemoglobinemia. May be fatal if inhaled or absorbed through skin. Vapors may be irritating and corrosive. It is a strong oxidizing agent. Contact with this chemical may cause burns and severe injury. Fire produces irritating, corrosive and toxic gases. Vapors from liquefied gas are initially heavier than air and spread across the ground.
Tetrafluorohydrazine explodes or ignites on contact with reducing agents at room temperature, including hydrogen, hydrocarbons, alcohols, thiols, amines, ammonia, hydrazines, dicyanogen, nitroalkanes, alkylberylliums, silanes, boranes or powdered metals. Prolonged exposure of the container of tetrafluorohydrazine to high heat may cause it to rupture vi
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https://en.wikipedia.org/wiki/AIMACO
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AIMACO is an acronym for AIr MAterial COmpiler. It began around 1959 as the definition of a high level programming language influenced by the FLOW-MATIC language, developed by UNIVAC, and the COMTRAN (COMmercial TRANslator) programming language, developed by IBM. AIMACO, along with FLOW-MATIC and COMTRAN, were precursors to the COBOL programming language and influenced its development.
A committee chaired by a representative of AMC (the Air Material Command, predecessor to the Air Force Materiel Command) and composed of industry representatives from IBM and United States Steel, as well as members of AMC Programming Services, developed the draft AIMACO language definition. Even though the word "compiler" was part of its name, no compiler was ever written for it; although at least two were specified or designed.
The original intention of AMC was that all programming for AMC systems worldwide would be written in AIMACO and compiled on a UNIVAC in AMC headquarters at Wright-Patterson Air Force Base, Dayton, Ohio. This would be for software whether it was intended to operate on UNIVAC or IBM computers. An alternative compiler was designed by AMC Programming Services persons to compile systems on IBM computers for operation on IBM computers.
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https://en.wikipedia.org/wiki/Afroinsectiphilia
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The Afroinsectiphilia (African insectivores) is a clade that has been proposed based on the results of recent molecular phylogenetic studies. Many of the taxa within it were once regarded as part of the order Insectivora, but Insectivora is now considered to be polyphyletic and obsolete. This proposed classification is based on molecular studies only, and there is no morphological evidence for it.
The golden moles, otter shrews and tenrecs are part of this clade. Some also regard the elephant shrews and aardvarks as part of it, although these two orders were traditionally seen as primitive ungulates. The sister group of the Afroinsectiphilia is the Paenungulata, which were also traditionally regarded as ungulates.
If the clade of Afrotheria is genuine, then the Afroinsectiphilia are the closest relatives of the Pseudoungulata (here regarded as part of Afroinsectiphilia) and the Paenungulata. In a classification governed by morphological data, both the Pseudoungulata and Paenungulata are seen as true ungulates, thus not related to Afroinsectiphilia. However, DNA research is thought to provide a more fundamental classification.
Additionally, there might be some dental synapomorphies uniting afroinsectiphilians: p4 talonid and trigonid of similar breadth,
a prominent p4 hypoconid, presence of a P4 metacone and absence of parastyles on M1–2. Additional features uniting ptolemaiidans and tubulidentates specifically include hypsodont molars that wear down to a flat surface; a long and shallow mandible with an elongated symphyseal region; and trigonids and talonids that are separated by lateral constrictions.
Taxonomy
INFRACLASS EUTHERIA: placental mammals
Superorder Afrotheria
Clade Afroinsectiphilia
Order Afrosoricida
Suborder Tenrecomorpha
Family Potamogalidae: otter shrews; 3 species in 2 genera
Family Tenrecidae: tenrecs; 31 extant species in 8 genera
†Incertae familiae: Genus Plesiorycteropus; extinct aardvark-like tenrec relatives from the Late Pleistoce
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https://en.wikipedia.org/wiki/Insite
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Insite is a supervised drug injection site in the Downtown Eastside (DTES) neighbourhood of Vancouver, British Columbia, Canada The DTES had 4700 chronic drug users in 2000 and has been considered to be the centre of an "injection drug epidemic". The site provides a supervised and health-focused location for injection drug use, primarily heroin. The clinic does not supply any drugs. Medical staff are present to provide addiction treatment, mental health assistance, and first aid in the event of an overdose or wound. In 2017, the site recorded 175,464 visits (an average of 480 injection room visits per day) by 7,301 unique users; 2,151 overdoses occurred with no fatalities, due to intervention by medical staff. The site also offers a free checking service so clients can check their substances for fentanyl and carfentanil. Health Canada has provided $500,000 per year to operate the site, and the BC Ministry of Health contributed $1,200,000 to renovate the site and cover operating costs. Insite also serves as a resource for those seeking to use a harm reduction approach for people who inject drugs around the world. In recent months and years, delegations from a number of countries are on record touring the facility, including various U.S. states, Colombia and Brazil. 95% of drug users who use Insite also inject on the street according to a British Columbia health official.
Operation
Insite is operated in tandem by Vancouver Coastal Health and the Portland Hotel Society. Between September 2003 and July 2008, the site operated under a special exemption of Section 56 of the Controlled Drugs and Substances Act, granted by the Liberal government via Health Canada. It is the first safe consumption site in North America. The site was slated to close on September 12, 2006, as the exemption was for a three-year pilot project. The Conservative minority government granted a temporary extension, then added another six-month extension that was to end in mid-2008. A constitutional
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https://en.wikipedia.org/wiki/MetaEdit%2B
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MetaEdit+ is an environment for creating and using Domain-Specific Modeling languages.
Research History
The research behind the genesis of MetaEdit+ was carried out at the University of Jyväskylä, as part of the MetaPHOR project. A metamodeling and modeling tool, MetaEdit, had been created by the earlier SYTI project in the late 1980s and early 1990s, in co-operation with a company, MetaCase.
Both MetaEdit and MetaEdit+ were described in a large number of publications from the MetaPHOR research group (including,).
Tool History
MetaEdit allowed graphical metamodeling using Object-Property-Role-Relationship (OPRR) data model, definition of the DSM language notation with a graphical symbol editor, and the definition of code generators using a Domain-Specific Language. These three elements together formed a metamodel file, which configured MetaEdit to support that modeling language.
MetaEdit 1.0 was released as shareware in 1993.
MetaEdit 1.1 was released as commercial software in 1993.
MetaEdit 1.2 was released in 1995.
The original MetaEdit was limited to supporting one modeling language at a time, one user at a time, and one representational paradigm - graphical diagrams. MetaEdit+ was designed to extend this to multiple integrated modeling languages, multiple simultaneous users, and multiple representational paradigms - diagrams, matrices and tables.
MetaEdit+ 2.0, the first version of MetaEdit+, was released by MetaCase in 1995 for Windows.
MetaEdit+ 2.5 was released in 1996, adding full multi-user facilities and support for Solaris and HP-UX.
MetaEdit+ 3.0 was released in 1999, with support for Linux and significant new functionality added in three Service Releases over the next few years.
MetaEdit+ 4.0 was released in 2004, with new Diagram and Symbol Editors, support for ports, and interoperability via SOAP and XML. Two Service Releases adding new functionality and support for Mac OS X.
MetaEdit+ 4.5 was released in 2006, adding graphical metamo
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https://en.wikipedia.org/wiki/Beta%20hairpin
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The beta hairpin (sometimes also called beta-ribbon or beta-beta unit) is a simple protein structural motif involving two beta strands that look like a hairpin. The motif consists of two strands that are adjacent in primary structure, oriented in an antiparallel direction (the N-terminus of one sheet is adjacent to the C-terminus of the next), and linked by a short loop of two to five amino acids. Beta hairpins can occur in isolation or as part of a series of hydrogen bonded strands that collectively comprise a beta sheet.
Researchers such as Francisco Blanco et al. have used protein NMR to show that beta-hairpins can be formed from isolated short peptides in aqueous solution, suggesting that hairpins could form nucleation sites for protein folding.
Classification
Beta hairpins were originally categorized solely by the number of amino acid residues in their loop sequences, such that they were named one-residue, two-residue, etc. This system, however, is somewhat ambiguous as it does not take into account whether the residues that signal the end of the hairpin are singly or doubly hydrogen bonded to one another. An improved means of classification has since been proposed by Milner-White and Poet. Beta hairpins are broken into four distinct classes as depicted in the publication's Figure 1. Each class begins with the smallest possible number of loop residues and progressively increases the loop size by removing hydrogen bonds in the beta sheet. The primary hairpin of class 1 is a one-residue loop where the bound residues share two hydrogen bonds. One hydrogen bond is then removed to create a three-residue loop, which is the secondary hairpin of class 1. Singly bound residues are counted in the loop sequence but also signal the end of the loop, thus defining this hairpin as a three-residue loop. This single hydrogen bond is then removed to create the tertiary hairpin; a five-residue loop with doubly bound residues. This pattern continues indefinitely and defines all
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https://en.wikipedia.org/wiki/National%20Institute%20of%20Aeronautics%20and%20Space
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The National Institute of Aeronautics and Space (, LAPAN) was the Indonesian government's space agency. It was established on 27 November 1963, by former Indonesian president Sukarno, after one year's existence of a previous, informal space agency organization. LAPAN is responsible for long-term civilian and military aerospace research.
For over two decades, LAPAN managed satellites, including the domain-developed small scientific-technology satellite LAPAN-TUBsat and the Palapa series of telecommunication satellites, which were built by Hughes (now Boeing Satellite Systems) and launched from the US on Delta rockets, or from French Guiana using Ariane 4 and Ariane 5 rockets. LAPAN has also developed sounding rockets and has been trying to develop small orbital space launchers. The LAPAN A1, in 2007, and LAPAN A2, in 2015, satellites were launched by India.
With the enactment of Presidential Decree No. 33/2021 on 5 May 2021, LAPAN is due to be disbanded along with government research agencies such as the Agency of Assessment and Application of Technology (Indonesian: Badan Pengkajian dan Penerapan Teknologi, BPPT), National Nuclear Energy Agency (Indonesian: Badan Tenaga Nuklir Nasional, BATAN), and Indonesian Institute of Sciences (Indonesian: Lembaga Ilmu Pengetahuan Indonesia, LIPI). All of those agencies fused into newly formed National Research and Innovation Agency (Indonesian: Badan Riset dan Inovasi Nasional, BRIN). As of September 2021, the disbandment process is still on process and expected to be finished on 1 January 2022.
On 1 September 2021, LAPAN was finally dissolved as an independent agency and transformed into the space and aeronautics research organization of BRIN, signaling the beginning of the institutional integration of the former LAPAN into BRIN.
History
On 31 May 1962, Indonesia commenced aeronautics exploration when the Aeronautics Committee was established by the Indonesian prime minister, Djuanda, who was also the head of Indonesian A
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https://en.wikipedia.org/wiki/Edmund%20Montgomery
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Edmund Duncan Montgomery (March 19, 1835 – April 17, 1911) was a Scottish-American philosopher, scientist and physician. He was the husband of German-American sculptor Elisabet Ney.
Early life
Montgomery was born on the 19th of March, 1835, in Edinburgh, Scotland. His parentage is unknown, but the Elisabet Ney Museum relates the possibility that he was the son of Isabella Davidson (or Montgomery) and a prominent Scottish jurist, Duncan McNeill, 1st Baron Colonsay. He and his mother lived in Paris and Frankfurt, supplemented by a trust fund for him.
By the time he entered his teens, he began to be interested in the philosophical works of Arthur Schopenhauer. While still living in Frankfurt and only 13 years old, he participated in the Revolutions of 1848 in the German states.
Education
In 1852, Montgomery studied medicine at the University of Heidelberg, where he did lab work under Robert Bunsen and came under the influence of Christian Kapp, Ludwig Andreas Feuerbach and Jacob Moleschott. He later attended lectures by Johannes Peter Müller at the University of Berlin during his 1855–1856 enrollment. While studying in Bonn 1856–1857, he attended influential lectures of Hermann von Helmholtz.
Medical practice
Montgomery received his MD degree from the University of Würzburg on February 18, 1858.
Montgomery interned at Prague and Vienna. He served his residency at the German Hospital, Dalston (London) and Bermondsay Dispensary. While doing biological research, he became Curator of the St Thomas' Hospital and Demonstrator of Morbid Anatomy. He was elected to the Royal College of Physicians of London in 1862.
After being diagnosed with tuberculosis in 1863, Montgomery left the Royal College of Physicians of London and established medical practices on the resort island of Madeira (1863–1865), in Menton (1866) on the French Riviera, and also in Rome (1867) and Munich (1868), while continuing to do his research. A life annuity allowed him to retire from medic
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https://en.wikipedia.org/wiki/MAX%20%28operating%20system%29
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MaX, also known as Madrid_linux is a linux distribution created with funds from the Conserjería de Educación, Juventud y Deporte of the Comunidad de Madrid adapted for use in educational environments. The main features of this operating system are simplicity, stability and a huge collection of software.
History
Start
MaX started out simply as an educational distribution made for lower performance computers, since most of the computers in the schools of the Comunidad de Madrid had only 32 bits and very little RAM, so they had problems with the main operating systems. Later, more members were joining the Max Group and were receiving suggestions for improvements, additions. In 2013 they already had 60 members, including professors of all kinds.
Desktop and Support
During the first versions of MaX it was used with the KDE desktop environment and only supported 32-bit computers of the i486 architecture, until MaX version 3, where the processor architecture was changed to i386, also 32-bit. In MaX version 4, the desktop environment was changed to GNOME, one of the most widely used in Linux, and in version 5 support for 64-bit computers with x86_64 architecture was added. In version 7, the desktop environment was changed to Xfce. In version 9 the desktop environment was changed again to Mate, and in version 11 support for 32-bit computers ended.
Activities performed
The MaX team has participated in events of schools, such as 'Program-me at IES Clara del Rey, with the purpose of supporting new talents; or with IES Príncipe Felipe at MediaLab Prado, to encourage diffusion of MaX.
Conferences
MaX has held many conferencess over the years, almost annually, to present future versions of MaX, create workshops, or hold install parties. The conference was held online in 2021.
Characteristics
Community
The community of users actively participates, testing the system, reporting problems, contributing with improvement proposals, helping other users or sharing with their peers
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https://en.wikipedia.org/wiki/Molinux
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Molinux was an operating system based on Ubuntu sponsored by the autonomous community of Castilla-La Mancha and the Fundación Ínsula Barataria.
The name "Molinux" derives from the Spanish word molino, meaning "mill" or "windmill". Each version of Molinux is named after a character from the classic Spanish novel Don Quixote, by Miguel de Cervantes.
Project information
Molinux was an initiative begun in 2005 by the government of Castilla-La Mancha to introduce the Castile-La Mancha community to the forefront of the Information Society. The Molinux project is intended to attack the digital divide by reducing the cost of software and offering an easy-to-use operating system.
The sponsoring regional government's commitment to the open source philosophy is such that they have committed not to impose the use of Molinux. "The advantage is that the software is free to compete with anyone, and the user can choose between using this or any other software."
Latest version
Molinux 6.2 (codename "Merlín") was launched on 2010-12-24. It was based on Ubuntu 10.10.
Main features
Based on Ubuntu "Lucid" 10.04
Linux kernel 2.6.32
GNOME 2.30
OpenOffice.org 3.2
Mozilla Firefox 3.6
X.Org Server 1.7
The distribution's artistic team has delivered new desktop backgrounds depicting images from the autonomous community and some abstract designs, as well as brand new icons for the panels, menus and desktop. An interesting new feature is a new backup manager that automates backing up of data to external devices or over the local network.
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https://en.wikipedia.org/wiki/Sommerfeld%20radiation%20condition
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In applied mathematics, and theoretical physics the Sommerfeld radiation condition is a concept from theory of differential equations and scattering theory used for choosing a particular solution to the Helmholtz equation. It was introduced by Arnold Sommerfeld in 1912
and is closely related to the limiting absorption principle (1905) and the limiting amplitude principle (1948).
The boundary condition established by the principle essentially chooses a solution of some wave equations which only radiates outwards from known sources. It, instead, of allowing arbitrary inbound waves from the infinity propagating in instead detracts from them.
The theorem most underpinned by the condition only holds true in three spatial dimensions. In two it breaks down because wave motion doesn't retain its power as one over radius squared. On the other hand, in spatial dimensions four and above, power in wave motion falls off much faster in distance.
Formulation
Arnold Sommerfeld defined the condition of radiation for a scalar field satisfying the Helmholtz equation as
"the sources must be sources, not sinks of energy. The energy which is radiated from the sources must scatter to infinity; no energy may be radiated from infinity into ... the field."
Mathematically, consider the inhomogeneous Helmholtz equation
where is the dimension of the space, is a given function with compact support representing a bounded source of energy, and is a constant, called the wavenumber. A solution to this equation is called radiating if it satisfies the Sommerfeld radiation condition
uniformly in all directions
(above, is the imaginary unit and is the Euclidean norm). Here, it is assumed that the time-harmonic field is If the time-harmonic field is instead one should replace with in the Sommerfeld radiation condition.
The Sommerfeld radiation condition is used to solve uniquely the Helmholtz equation. For example, consider the problem of radiation due to a point source in three
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https://en.wikipedia.org/wiki/Xtraview%20Encryption%20System
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Xtraview Video Encryption System refers to the now-defunct patented "encryption" system used on Xtraview and a number of other Top Up TV services, including Setanta Sports, Television X, Babestation and Red Hot TV.
Unlike the other encryption system used by Top Up TV, Mediaguard, the Xtraview Video Encryption System was not a true encryption system. Instead, an MHEG application directed the user's set-top box to a hidden videostream when a correct PIN is entered. Unlike traditional channel encryption methods, Xtraview did not require a viewing card. This is an advantage over digital terrestrial television in the UK, where the vast majority of set-top boxes have no ability to decrypt pay channels.
Access to a channel protected using the Xtraview technology was granted by calling a premium rate telephone number. During the call, users were asked to give a number displayed on screen. In response, they were given a PIN to unlock the service.
a similar system is in use by Babestation Xtreme, Red Hot TV, Television X and briefly by the now defunct TView on digital terrestrial television.
Criticism
The PIN system has been subject to widespread hacking. Without encryption, the system was easily circumvented by set-top boxes that are able to access individual videostreams when individual stream PIDs are entered. More recently, the PIN algorithm itself was cracked, allowing others to access the service.
Another downfall is that because the application is MHEG generated, if the set-top box was switched off, access to these channels was lost. It is also stated on-screen before purchase that not all boxes are compatible. Another factor is that a few cheaper boxes do not have MHEG support at all, and therefore cannot access the service.
External links
Top Up TV Homepage
Digital rights management systems
Television technology
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https://en.wikipedia.org/wiki/Necklace%20%28combinatorics%29
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In combinatorics, a k-ary necklace of length n is an equivalence class of n-character strings over an alphabet of size k, taking all rotations as equivalent. It represents a structure with n circularly connected beads which have k available colors.
A k-ary bracelet, also referred to as a turnover (or free) necklace, is a necklace such that strings may also be equivalent under reflection. That is, given two strings, if each is the reverse of the other, they belong to the same equivalence class. For this reason, a necklace might also be called a fixed necklace to distinguish it from a turnover necklace.
Formally, one may represent a necklace as an orbit of the cyclic group acting on n-character strings over an alphabet of size k, and a bracelet as an orbit of the dihedral group. One can count these orbits, and thus necklaces and bracelets, using Pólya's enumeration theorem.
Equivalence classes
Number of necklaces
There are
different k-ary necklaces of length n, where is Euler's totient function. This follows directly from Pólya's enumeration theorem applied to the action of the cyclic group acting on the set of all functions .
There are also
different necklaces of length n with exactly k different colored beads, where are the Stirling number of the second kind. (The variable k is overloaded and it is unclear whether k refers to the alphabet size or to the number of distinct elements in the necklace.)
and are related via the Binomial coefficients:
and
Number of bracelets
There are a total of
different k-ary bracelets of length n, where Nk(n) is the number of k-ary necklaces of length n. This follows from Pólya's method applied to the action of the dihedral group .
Case of distinct beads
For a given set of n beads, all distinct, the number of distinct necklaces made from these beads, counting rotated necklaces as the same, is = (n − 1)!. This is because the beads can be linearly ordered in n! ways, and the n circular shifts of s
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https://en.wikipedia.org/wiki/Brodifacoum
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Brodifacoum is a highly lethal 4-hydroxycoumarin vitamin K antagonist anticoagulant poison. In recent years, it has become one of the world's most widely used pesticides. It is typically used as a rodenticide, but is also used to control larger pests such as possums.
Brodifacoum has an especially long half-life in the body, which ranges up to nine months, requiring prolonged treatment with antidotal vitamin K for both human and pet poisonings. It has one of the highest risks of secondary poisoning to both mammals and birds. Significant experience in brodifacoum poisonings has been gained in many human cases where it has been used in attempted suicides, necessitating long periods of vitamin K treatment. In March 2018, cases of severe coagulopathy and bleeding associated with synthetic cannabinoid use contaminated with brodifacoum were reported in five states of the US.
Chemical synthesis
Brodifacoum is a derivative of the 4-hydroxy-coumarin group. Compounds numbers are found next to their respective compounds in the image below. Compound 1 is the starting ester needed to synthesize brodifacoum. To obtain this starting Compound 1, a simple Wittig condensation of ethyl chloroacetate with 4’-bromobiphenylcarboxaldehyde is accomplished. Compound 1 is transformed into Compound 2 by consecutive hydrolysis, halogenation to form an acid chloride, and then reacted with the required lithium anion. This is done using KOH and EtOH for hydrolysis, and then adding SOCl2 for chlorination to form the acid chloride which reacts with the addition of lithium anion. Compound 2 is then transformed using organocopper chemistry to yield Compound 3 with good stereoselectivity of about 98%. Typically, a Friedel-Crafts type cyclization would then be used to obtain the two-ring system portion of Compound 4, but this results in low yield. Instead, trifluoromethanesulfonic acid in dry benzene catalyzes the cyclization with good yield. The ketone is then reduced with sodium borohydride yieldi
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https://en.wikipedia.org/wiki/Oskar%20Kraus
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Oskar Kraus (24 July 1872 – 26 September 1942) was a Czech philosopher and jurist.
Life
Oskar Kraus, who converted from the Jewish to the Protestant faith, was born in Prague, the son of Hermann Kraus and Clara Reitler-Eidlitz. In 1899 he married Bertha Chitz.
In 1890 he began to study jurisprudence and philosophy under Friedrich Jodl and Anton Marty, who introduced him into Franz Brentano's philosophy. Kraus made his Doctor of Philosophy in 1895 and attained the habilitation in philosophy in 1902. In 1909 he became Professor extraordinarius and in 1916 Professor ordinarius. After the Germans occupied Czechoslovakia in 1939, Kraus was put into a concentration camp; however, after he was released he fled to Great Britain. At the University Edinburgh he held Gifford Lectures in 1941. In 1942 he died, aged 70, in Oxford, of cancer.
Family:
Wally Oskarovich Kraus (1930 – 21 October 1981) — son, died in an accident
Yuriy Voldemarovich Kraus (b. 30 March 1966 in Tallinn)
Work
During World War I, Kraus worked on topics in relation to war and ethics and wrote important works in the field of public international law.
Influenced by Brentano, Kraus developed an a priori value theory, which was formulated in opposition to Marxian value theory. He also applied this method on economics.
Based on his ideas on law and duty he developed a juristic hermeneutics in the field of jurisprudence, and criticized historism and positivism.
Kraus was also known for his criticism of the theory of relativity, which was according to him an accumulation of "absurdities" (like the constancy of the speed of light) and "mathematical fictions".
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https://en.wikipedia.org/wiki/HEC-RAS
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HEC-RAS is simulation software used in computational fluid dynamics – specifically, to model the hydraulics of water flow through natural rivers and other channels. Prior to the 2016 update to Version 5.0, the program was one-dimensional, meaning that there is no direct modeling of the hydraulic effect of cross section shape changes, bends, and other two- and three-dimensional aspects of flow. The release of Version 5.0 introduced two-dimensional modeling of flow as well as sediment transfer modeling capabilities. The program was developed by the United States Army Corps of Engineers in order to manage the rivers, harbors, and other public works under their jurisdiction; it has found wide acceptance by many others since its public release in 1995.
The Hydrologic Engineering Center (HEC) in Davis, California, developed the River Analysis System (RAS) to aid hydraulic engineers in channel flow analysis and floodplain determination. It includes numerous data entry capabilities, hydraulic analysis components, data storage and management capabilities, and graphing and reporting capabilities.
Functionality
The basic computational procedure of HEC-RAS for steady flow is based on the solution of the one-dimensional energy equation. Energy losses are evaluated by friction and contraction / expansion. The momentum equation may be used in situations where the water surface profile is rapidly varied. These situations include hydraulic jumps, hydraulics of bridges, and evaluating profiles at river confluences.
For unsteady flow, HEC-RAS solves the full, dynamic, 1-D Saint Venant Equation using an implicit, finite difference method. The unsteady flow equation solver was adapted from Dr. Robert L. Barkau's UNET package.
HEC-RAS is equipped to model a network of channels, a dendritic system or a single river reach. Certain simplifications must be made in order to model some complex flow situations using the HEC-RAS one-dimensional approach. It is capable of modeling subcrit
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https://en.wikipedia.org/wiki/Plated-wire%20memory
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Plated-wire memory is a variation of core memory developed by Bell Laboratories in 1957. Its primary advantage was that it could be machine-assembled, which potentially led to lower prices than the almost always hand-assembled core.
Instead of threading individual ferrite cores on wires, plated-wire memory used a grid of wires coated with a thin layer of iron–nickel alloy called permalloy. The magnetic field normally stored in the ferrite core was instead stored on the wire itself. Operation was generally similar to core memory, with the wire itself acting as the data line, and the magnetic domains providing the individual bit locations defined by address (word) lines running on either side of (and perpendicular to) the data wire.
Early versions operated in a destructive read mode, requiring a write after read to restore data. Non-destructive read mode was possible, but this required much greater uniformity of the magnetic coating.
Improvements in semiconductor RAM chips provided the higher storage densities and higher speeds needed for large-scale application such as mainframe computers, replacing previous types of memory, including both core and plated-wire memory.
Plated-wire memory has been used in a number of applications, typically in aerospace. It was used in the UNIVAC 1110 and UNIVAC 9000 series computers, the Viking program that sent landers to Mars, the Voyager space probes, a prototype guidance computer for the Minuteman-III, the Space Shuttle Main Engine controllers, the KH-9 Hexagon reconnaissance satellite, and in the Hubble Space Telescope.
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https://en.wikipedia.org/wiki/Hardware%20keylogger
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Hardware keyloggers are used for keystroke logging, a method of capturing and recording computer users' keystrokes, including sensitive passwords. They can be implemented via BIOS-level firmware, or alternatively, via a device plugged inline between a computer keyboard and a computer. They log all keyboard activity to their internal memory.
Description
Hardware keyloggers have an advantage over software keyloggers as they can begin logging from the moment a computer is turned on (and are therefore able to intercept passwords for the BIOS or disk encryption software).
All hardware keylogger devices have to have the following:
A microcontroller - this interprets the datastream between the keyboard and computer, processes it, and passes it to the non-volatile memory
A non-volatile memory device, such as flash memory - this stores the recorded data, retaining it even when power is lost
Generally, recorded data is retrieved by typing a special password into a computer text editor. The hardware keylogger plugged in between the keyboard and computer detects that the password has been typed and then presents the computer with "typed" data to produce a menu. Beyond text menu some keyloggers offer a high-speed download to speed up retrieval of stored data; this can be via USB mass-storage enumeration or with a USB or serial download adapter.
Typically the memory capacity of a hardware keylogger may range from a few kilobytes to several gigabytes, with each keystroke recorded typically consuming a byte of memory.
Types of hardware keyloggers
A regular hardware keylogger is used for keystroke logging by means of a hardware circuit that is attached somewhere in between the computer keyboard and the computer. It logs all keyboard activity to its internal memory which can be accessed by typing in a series of pre-defined characters. A hardware keylogger has an advantage over a software solution; because it is not dependent on the computer's operating system it will not i
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https://en.wikipedia.org/wiki/Association%20of%20the%20British%20Pharmaceutical%20Industry
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The Association of the British Pharmaceutical Industry (ABPI) is the trade association for over 120 companies in the UK producing prescription medicines for humans, founded in 1891. It is the British equivalent of America's PhRMA; however, the member companies research, develop, manufacture and supply medicines prescribed for the National Health Service.
History
The organisation was founded in London in 1891 and originally known as the "Drug Club". It was re-named the Association of the British Pharmaceutical Industry in 1948. A rival institution to represent wholesalers, the "Northern Wholesale Druggists' Association", was formed in 1902 and lasted until 1966.
Management and offices
A board of management of members oversee the ABPI. The Board is made up of individuals who are elected by members to represent the industry and up to five people who are co-opted by the Board. Elections commence every January for elected seats to ensure that the Board is fully representative and has access to the broadest range of skills and expertise possible.
The ABPI's head office is in London with three regional offices in Cardiff, Belfast and Edinburgh.
Membership
Membership of the Association of the British Pharmaceutical Industry is not open to individuals, only companies. Members fall into three categories:
Full members who hold marketing authorisation for manufacture or supply of a prescription medicine for human use and who undertake business in the UK
Research affiliate members who carry out business in the UK and are involved in research and/or development of medicines for human use but do not have a UK sales operation, for example contract research organisations or contract manufacturing organizations
General affiliate members who operate in the UK, have a business interest in the industry and will typically provide products or services to the industry, although not producing prescription medicines, for example law firms
Functions
The ABPI represents the views of t
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https://en.wikipedia.org/wiki/Cell%20physiology
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Cell physiology is the biological study of the activities that take place in a cell to keep it alive. The term physiology refers to normal functions in a living organism. Animal cells, plant cells and microorganism cells show similarities in their functions even though they vary in structure.
General characteristics
There are two types of cells: prokaryotes and eukaryotes.
Prokaryotes were the first of the two to develop and do not have a self-contained nucleus. Their mechanisms are simpler than later-evolved eukaryotes, which contain a nucleus that envelops the cell's DNA and some organelles.
Prokaryotes
Prokaryotes have DNA located in an area called the nucleoid, which is not separated from other parts of the cell by a membrane. There are two domains of prokaryotes: bacteria and archaea. Prokaryotes have fewer organelles than eukaryotes. Both have plasma membranes and ribosomes (structures that synthesize proteins and float free in cytoplasm). Two unique characteristics of prokaryotes are fimbriae (finger-like projections on the surface of a cell) and flagella (threadlike structures that aid movement).
Eukaryotes
Eukaryotes have a nucleus where DNA is contained. They are usually larger than prokaryotes and contain many more organelles. The nucleus, the feature of a eukaryote that distinguishes it from a prokaryote, contains a nuclear envelope, nucleolus and chromatin. In cytoplasm, endoplasmic reticulum (ER) synthesizes membranes and performs other metabolic activities. There are two types, rough ER (containing ribosomes) and smooth ER (lacking ribosomes). The Golgi apparatus consists of multiple membranous sacs, responsible for manufacturing and shipping out materials such as proteins. Lysosomes are structures that use enzymes to break down substances through phagocytosis, a process that comprises endocytosis and exocytosis. In the mitochondria, metabolic processes such as cellular respiration occur. The cytoskeleton is made of fibers that support the str
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https://en.wikipedia.org/wiki/Sea%2C%20Lake%2C%20and%20Overland%20Surge%20from%20Hurricanes
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Sea, Lake, and Overland Surge from Hurricanes (SLOSH) is a computerized model developed by the Federal Emergency Management Agency (FEMA), United States Army Corps of Engineers (USACE), and the National Weather Service (NWS), to estimate storm surge depths resulting from historical, hypothetical, or predicted hurricanes. The model functions by taking into account a storm's pressure, size, forward speed, forecast track, wind speeds, and topographical data.
SLOSH is used to evaluate the threat from storm surge, and emergency managers use this data to determine which areas must be evacuated. SLOSH output is used by the National Hurricane Program (NHP) when conducting Hurricane Evacuation Studies as a hazard analysis tool for assisting with the creation of state and local hurricane evacuation plans or zones. SLOSH model results are combined with roadway network and traffic flow information, rainfall amounts, river flow, or wind-driven waves to determine a final analysis of at-risk areas.
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https://en.wikipedia.org/wiki/Stubline%20transmitter
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Stubline transmitter is a broadcasting facility for mediumwave and shortwave near Zvečka, Serbia. The mediumwave transmitter broadcast on 684 kHz and, until its destruction on May 30, 1999, it was one of the strongest in Europe having used 2000 kilowatts of power.
The station was rebuilt with a 225.5 metres tall mast, but nowadays uses less power.
See also
List of tallest structures in Serbia
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https://en.wikipedia.org/wiki/Military%20meteorology
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Military meteorology is meteorology applied to military purposes, by armed forces or other agencies. It is one of the most common fields of employment for meteorologists.
World War II brought great advances in meteorology as large-scale military land, sea, and air campaigns were highly dependent on weather, particularly forecasts provided by the Royal Navy, Met Office and USAAF for the Normandy landing and strategic bombing.
University meteorology departments grew rapidly as the military services sent cadets to be trained as weather officers. Wartime technological developments such as radar also proved to be valuable meteorological observing systems. More recently, the use of satellites in space has contributed extensively to military meteorology.
Military meteorologists currently operate with a wide variety of military units, from aircraft carriers to special forces.
Military meteorology in the United States
United States Navy/Marine Corps
Chain of command
Naval Meteorology and Oceanography Command
Fleet Numerical Meteorology and Oceanography Center
Enlisted
Enlisted meteorology and oceanography forecasters are called aerographer's mates.
Officer
Naval meteorology and oceanography officers are restricted line officers in the Information Dominance Corps.
Notable military meteorologists
Capt Homer A. McCrerey, USNA Class of 1942, fleet meteorologist and oceanographer (FNMOC) (1967–1972)
Gp Capt James Martin Stagg, military meteorologist for Operation Overlord 1944
See also
U.S. Air Force 557th Weather Wing
U.S. Air Force Special Operations Weather Technician
Navy Operational Global Atmospheric Prediction System
Weather forecasting for Operation Overlord
Further reading
John F. Fuller (1974), Weather and War, Military Airlift Command, U.S. Air Force
Thomas Haldane, War History of the Australian Meteorological Service in the Royal Australian Air Force April 1941 to July 1946, accessed at Australian Science and Technology Heritage Centre, University o
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https://en.wikipedia.org/wiki/Expander%20mixing%20lemma
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The expander mixing lemma intuitively states that the edges of certain -regular graphs are evenly distributed throughout the graph. In particular, the number of edges between two vertex subsets and is always close to the expected number of edges between them in a random -regular graph, namely .
d-Regular Expander Graphs
Define an -graph to be a -regular graph on vertices such that all of the eigenvalues of its adjacency matrix except one have absolute value at most The -regularity of the graph guarantees that its largest absolute value of an eigenvalue is In fact, the all-1's vector is an eigenvector of with eigenvalue , and the eigenvalues of the adjacency matrix will never exceed the maximum degree of in absolute value.
If we fix and then -graphs form a family of expander graphs with a constant spectral gap.
Statement
Let be an -graph. For any two subsets , let be the number of edges between S and T (counting edges contained in the intersection of S and T twice). Then
Tighter Bound
We can in fact show that
using similar techniques.
Biregular Graphs
For biregular graphs, we have the following variation, where we take to be the second largest eigenvalue.
Let be a bipartite graph such that every vertex in is adjacent to vertices of and every vertex in is adjacent to vertices of . Let with and . Let . Then
Note that is the largest eigenvalue of .
Proofs
Proof of First Statement
Let be the adjacency matrix of and let be the eigenvalues of (these eigenvalues are real because is symmetric). We know that with corresponding eigenvector , the normalization of the all-1's vector. Define and note that . Because is symmetric, we can pick eigenvectors of corresponding to eigenvalues so that forms an orthonormal basis of .
Let be the matrix of all 1's. Note that is an eigenvector of with eigenvalue and each other , being perpendicular to , is an eigenvector of with eigenvalue 0. For a vertex subset , let be the column
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https://en.wikipedia.org/wiki/Brian%20Schmidt
|
Brian Paul Schmidt (born 24 February 1967) is the Vice-Chancellor of the Australian National University (ANU). He was previously a Distinguished Professor, Australian Research Council Laureate Fellow and astrophysicist at the University's Mount Stromlo Observatory and Research School of Astronomy and Astrophysics. He is known for his research in using supernovae as cosmological probes. He currently holds an Australian Research Council Federation Fellowship and was elected a Fellow of the Royal Society (FRS) in 2012. Schmidt shared both the 2006 Shaw Prize in Astronomy and the 2011 Nobel Prize in Physics with Saul Perlmutter and Adam Riess for providing evidence that the expansion of the universe is accelerating, making him the only Montana-born Nobel laureate.
Early life and education
Schmidt, an only child, was born in Missoula, Montana, where his father Dana C. Schmidt was a fisheries biologist. When he was 13, his family relocated to Anchorage, Alaska.
Schmidt attended Bartlett High School in Anchorage, Alaska, and graduated in 1985. He has said that he wanted to be a meteorologist "since I was about five-years-old [but] ... I did some work at the USA National Weather Service up in Anchorage and didn't enjoy it very much. It was less scientific, not as exciting as I thought it would be—there was a lot of routine. But I guess I was just a little naive about what being a meteorologist meant." His decision to study astronomy, which he had seen as "a minor pastime", was made just before he enrolled at university. Even then, he was not fully committed: he said "I'll do astronomy and change into something else later", and just never made that change.
He graduated with a BS (Physics) and BS (Astronomy) from the University of Arizona in 1989. He received his AM (Astronomy) in 1992 and then PhD (Astronomy) in 1993 from Harvard University. Schmidt's PhD thesis was supervised by Robert Kirshner and used Type II Supernovae to measure the Hubble Constant.
While at Harva
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https://en.wikipedia.org/wiki/Nucleotidase
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A nucleotidase is a hydrolytic enzyme that catalyzes the hydrolysis of a nucleotide into a nucleoside and a phosphate.
A nucleotide + H2O = a nucleoside + phosphate
For example, it converts adenosine monophosphate to adenosine, and guanosine monophosphate to guanosine.
Nucleotidases have an important function in digestion in that they break down consumed nucleic acids.
They can be divided into two categories, based upon the end that is hydrolyzed:
: 5'-nucleotidase - NT5C, NT5C1A, NT5C1B, NT5C2, NT5C3
: 3'-nucleotidase - NT3
5'-Nucleotidases cleave off the phosphate from the 5' end of the sugar moiety. They can be classified into various kinds depending on their substrate preferences and subcellular localization. Membrane-bound 5'-nucleotidases display specificity toward adenosine monophosphates and are involved predominantly in the salvage of preformed nucleotides and in signal transduction cascades involving purinergic receptors. Soluble 5'-nucleotidases are all known to belong to the haloacid dehalogenase superfamily of enzymes, which are two domain proteins characterised by a modified Rossman fold as the core and variable cap or hood. The soluble forms are further subclassified based on the criterion mentioned above. mdN and cdN are mitochondrial and cytosolic 5'-3'-pyrimidine nucleotidases. cN-I is a cytosolic nucleotidase(cN) characterized by its affinity toward AMP as its substrate. cN-II is identified by its affinity toward either IMP or GMP or both. cN-III is a pyrimidine 5'-nucleotidase. A new class of nucleotidases called IMP-specific 5'-nucleotidase has been recently defined. 5'-Nucleotidases are involved in varied functions like cell–cell communication, nucleic acid repair, purine salvage pathway for the synthesis of nucleotides, signal transduction, membrane transport, etc.
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https://en.wikipedia.org/wiki/Nine%20dots%20puzzle
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The nine dots puzzle is a mathematical puzzle whose task is to connect nine squarely arranged points with a pen by four (or fewer) straight lines without lifting the pen.
The puzzle has appeared under various other names over the years.
History
In 1867, in the French chess journal Le Sphinx, an intellectual precursor to the nine dots puzzle appeared credited to Sam Loyd. Said chess puzzle corresponds to a "64 dots puzzle", i.e., marking all dots of an 8-by-8 square lattice, with an added constraint.
In 1907, the nine dots puzzle appears in an interview with Sam Loyd in The Strand Magazine:
"[...] Suddenly a puzzle came into my mind and I sketched it for him. Here it is. [...] The problem is to draw straight lines to connect these eggs in the smallest possible number of strokes. The lines may pass through one egg twice and may cross. I called it the Columbus Egg Puzzle."
In the same year, the puzzle also appeared in A. Cyril Pearson's puzzle book. It was there named a charming puzzle and involved nine dots.
Both versions of the puzzle thereafter appeared in newspapers. From at least 1908, Loyd's egg-version ran as advertising for Elgin Creamery Co in Washington, DC., renamed to The Elgin Creamery Egg Puzzle. From at least 1910, Pearson's "nine dots"-version appeared in puzzle sections.
In 1914, Sam Loyd's Cyclopedia of Puzzles is published posthumously by his son (also named Sam Loyd). The puzzle is therein explained as follows:
The funny old King is now trying to work out a second puzzle, which is to draw a continuous line through the center of all of the eggs so as to mark them off in the fewest number of strokes. King Puzzlepate performs the feat in six strokes, but from Tommy's expression we take it to be a very stupid answer, so we expect our clever puzzlists to do better; [...]
Sam Loyd's naming of the puzzle is an allusion to the story of Egg of Columbus.
In the 1941 compilation The Puzzle-Mine: Puzzles Collected from the Works of the Late Henry
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https://en.wikipedia.org/wiki/Elaeagnus%20multiflora
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Elaeagnus multiflora, the cherry elaeagnus, cherry silverberry, goumi, gumi, or natsugumi, is a species of Elaeagnus native to China, Korea, and Japan.
Elaeagnus multiflora is a deciduous or semi-evergreen shrub or small tree growing to tall, with a trunk up to diameter with dark brown bark. The shoots are densely covered in minute red-brown scales. The leaves are ovate to elliptic, long and broad, green above, and silvery to orange-brown below with dense small scales.
The flowers are solitary or in pairs in the leaf axils, fragrant, with a four-lobed pale yellowish-white corolla long; flowering is in mid-spring.
The fruit is a round to oval drupe long, silvery-scaled orange, ripening red dotted with silver or brown, pendulous on a peduncle. When ripe in mid- to late summer, the fruit is juicy and edible, with a sweet but astringent taste somewhat similar to that of rhubarb. The skin of the fruit is thin and fragile, making it difficult to transport, thus reducing its viability as a food crop.
As with other species in the genus Elaeagnus, E. multiflora plants are actinorhizal, growing in symbiosis with the bacterium Frankia in the soil. These bacteria fix atmospheric nitrogen, making it available in usable form for the host plant, and indirectly for other nearby plants. This feature allows the plant to grow in poorer soils than it could otherwise.
Uses
This species is occasionally grown in Europe and North America as an ornamental plant and for its fruit. It is an established exotic species in parts of the eastern United States.
In China, the leaves of the tree are used as a medicinal plant and a natural remedy for cough, diarrhea, itch, foul sores, and, even, cancer.
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https://en.wikipedia.org/wiki/Neutral%20buoyancy
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Neutral buoyancy occurs when an object's average density is equal to the density of the fluid in which it is immersed, resulting in the buoyant force balancing the force of gravity that would otherwise cause the object to sink (if the body's density is greater than the density of the fluid in which it is immersed) or rise (if it is less). An object that has neutral buoyancy will neither sink nor rise.
In scuba diving, the ability to maintain neutral buoyancy through controlled breathing, accurate weighting, and management of the buoyancy compensator is an important skill. A scuba diver maintains neutral buoyancy by continuous correction, usually by controlled breathing, as neutral buoyancy is an unstable condition for a compressible object in a liquid.
History
The mathematician Archimedes discovered much of how buoyancy works more than 2000 years ago. In his research, Archimedes discovered that an object is buoyed up by a force equal to the weight of the water displaced by the object. In other words, an inflatable boat that displaces 100 pounds (45 kilograms) of water is supported by the same amount of force. An object that floats in a fluid is known as being positively buoyant. An object that sinks to the bottom is negatively buoyant, while an object that remains in balance at the same level in the fluid is neutrally buoyant. Ways to adjust buoyancy were developed to produce equipment such as the inflatable life jacket, which is filled with gas and helps to reduce a person's average density, assisting in floating and swimming, as well as certain diving equipment (including submarines and submersibles) which have adjustable volume air chambers to regulate buoyancy.
Uses
Buoyancy is important in many fields. Boats, ships and seaplanes are engineered in a way that ensures that they remain afloat. Submarines have controllable buoyancy to make them submerge and rise on demand. Many objects were developed with buoyancy in mind, such as life preservers and pontoons.
B
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https://en.wikipedia.org/wiki/RTI%20International
|
Research Triangle Institute, trading as RTI International, is a nonprofit organization headquartered in the Research Triangle Park in North Carolina, USA. RTI provides research and technical services. It was founded in 1958 with $500,000 in funding from local businesses and the three North Carolina universities that form the Research Triangle. RTI research has covered topics like HIV/AIDS, healthcare, education curriculum and the environment. The US Agency for International Development accounts for about 35 percent of RTI's research revenue.
History
In 1954, a building contractor, met with the North Carolina state treasurer and the president of Wachovia to discuss building a research park in North Carolina to attract new industries to the region. They obtained support for the concept from the state governor, Luther Hodges, and the three universities that form the research triangle: University of North Carolina at Chapel Hill, Duke University and North Carolina State University. The Research Triangle Institute (now RTI International) was formed by the park's founders as the research park's first tenant in 1958. The following January, they announced that $1.425 million had been raised by the Research Triangle Foundation to fund the park and that $500,000 of it had been set aside for RTI International.
RTI started with three divisions: Isotope Development, Operational Sciences and Statistics Research. Its first contract was a $4,500 statistical study of morbidity data from Tennessee. In RTI's first year of operation, it had 25 staff and $240,000 in research contracts. Its early work was focused on statistics, but within a few years RTI expanded into radioisotopes, organic chemistry and polymers. In 1960, the institute had its first international research contract for an agricultural census in Nigeria. RTI won contracts with the Department of Education, Defense Department, NASA and the Atomic Energy Commission, growing to $3.4 million in contracts in 1964 and $85 mil
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https://en.wikipedia.org/wiki/Cumulative%20prospect%20theory
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Cumulative prospect theory (CPT) is a model for descriptive decisions under risk and uncertainty which was introduced by Amos Tversky and Daniel Kahneman in 1992 (Tversky, Kahneman, 1992). It is a further development and variant of prospect theory. The difference between this version and the original version of prospect theory is that weighting is applied to the cumulative probability distribution function, as in rank-dependent expected utility theory but not applied to the probabilities of individual outcomes. In 2002, Daniel Kahneman received the Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel for his contributions to behavioral economics, in particular the development of Cumulative Prospect Theory (CPT).
Outline of the model
The main observation of CPT (and its predecessor prospect theory) is that people tend to think of possible outcomes usually relative to a certain reference point (often the status quo) rather than to the final status, a phenomenon which is called framing effect. Moreover, they have different risk attitudes towards gains (i.e. outcomes above the reference point) and losses (i.e. outcomes below the reference point) and care generally more about potential losses than potential gains (loss aversion). Finally, people tend to overweight extreme events, but underweight "average" events. The last point is in contrast to Prospect Theory which assumes that people overweight unlikely events, independently of their relative outcomes.
CPT incorporates these observations in a modification of expected utility theory by replacing final wealth with payoffs relative to the reference point, replacing the utility function with a value function that depends on relative payoff, and replacing cumulative probabilities with weighted cumulative probabilities.
In the general case, this leads to the following formula for subjective utility of a risky outcome described by probability measure :
where is the value function (typical form shown in F
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https://en.wikipedia.org/wiki/Viral%20culture
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Viral culture is a laboratory technique in which samples of a virus are placed to different cell lines which the virus being tested for its ability to infect. If the cells show changes, known as cytopathic effects, then the culture is positive.
Traditional viral culture has been generally superseded by shell vial culture, in which the sample is centrifuged onto a single layer of cells and viral growth is measured by antigen detection methods. This greatly reduces the time to detection for slow growing viruses such as cytomegalovirus, for which the method was developed. In addition, the centrifugation step in shell vial culture enhances the sensitivity of this method because after centrifugation, the viral particles of the sample are in close proximity to the cells.
Human and monkey cells are used in both traditional viral culture and shell vial culture.
Human virus types that can be identified by viral culture include adenovirus, cytomegalovirus, enteroviruses, herpes simplex virus, influenza virus, parainfluenza virus, rhinovirus, respiratory syncytial virus, varicella zoster virus, measles and mumps. For these, the final identification method is generally by immunofluorescence, with exception of cytomegalovirus and rhinovirus, whose identification in a viral culture are determined by cytopathic effects.
Preliminary research (i.e. not yet peer reviewed at the time of writing, 29 September 2020) exploring the potential suitability of viral culture testing of SARS-CoV-2 has been conducted.
See also
Cell culture
Instruments used in microbiology
Laboratory diagnosis of viral infections
Viral plaque
Viral disease testing
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https://en.wikipedia.org/wiki/Pre-embryo
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In human embryonic development a pre-embryo is a conceptus before implantation in the uterus.
Pre-embryo in human embryonic development
The word pre-embryo sometimes is used in ethical contexts to refer to a human conceptus at least between fertilization and implantation, though this term has not been adopted by the scientific community. A conceptus between fertilization and implantation is also frequently classified as a pre-implantation embryo.
Even after implantation begins, a pre-embryo may exist up until formation of the primitive streak. Implantation begins at about six days after fertilization, and lasts for about a week, during which time formation of the primitive streak occurs.
Use of the term pre-embryo, in the context of human development, has drawn criticism from opponents of embryo research, and from scientists who have considered this categorization invalid or unnecessary. One rationale that has been advanced for distinguishing an early fertilized human conceptus from an embryo is that there is a potential for the conceptus to split into identical twins prior to implantation, and so (the argument goes) the conceptus cannot be regarded before implantation as a single human being. However, the conceptus before implantation exhibits self-actuated activity, which has led to the assertion that it is an embryo. Further, identical twinning is an instance of asexual reproduction whereby a conceptus, without ceasing to be what it is (a new human being), provides a cell or cells as a new conceptus, entirely separated or partially separated (a 'siamese' twin) from the original conceptus, but in any event self-actuated in its development from the moment that the act of asexual reproduction (twinning) is complete. By this asexual reproduction, the parents of the original conceptus in effect become grandparents to the identical twin so conceived.
In the United States, a report by the National Institutes of Health stated that a conceptus could be both a pre-
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https://en.wikipedia.org/wiki/Compartmentalization%20%28information%20security%29
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Compartmentalization, in information security, whether public or private, is the limiting of access to information to persons or other entities on a need-to-know basis to perform certain tasks.
It originated in the handling of classified information in military and intelligence applications. It dates back to antiquity, and was successfully used to keep the secret of Greek fire.
The basis for compartmentalization is the idea that, if fewer people know the details of a mission or task, the risk or likelihood that such information will be compromised or fall into the hands of the opposition is decreased. Hence, varying levels of clearance within organizations exist. Yet, even if someone has the highest clearance, certain "compartmentalized" information, identified by codewords referring to particular types of secret information, may still be restricted to certain operators, even with a lower overall security clearance. Information marked this way is said to be codeword–classified. One famous example of this was the Ultra secret, where documents were marked "Top Secret Ultra": "Top Secret" marked its security level, and the "Ultra" keyword further restricted its readership to only those cleared to read "Ultra" documents.
Compartmentalization is now also used in commercial security engineering as a technique to protect information such as medical records.
Example
An example of compartmentalization was the Manhattan Project. Personnel at Oak Ridge constructed and operated centrifuges to isolate uranium-235 from naturally occurring uranium, but most did not know exactly what they were doing. Those that knew did not know why they were doing it. Parts of the weapon were separately designed by teams who did not know how the parts interacted.
See also
Information sensitivity
Principle of least privilege
Read into
Sensitive compartmented information
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https://en.wikipedia.org/wiki/Compartmentalization%20%28psychology%29
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Compartmentalization is a form of psychological defense mechanism in which thoughts and feelings that seem to conflict are kept separated or isolated from each other in the mind. Those with post traumatic stress disorder may use compartmentalization to separate positive and negative self aspects. It may be a form of mild dissociation; example scenarios that suggest compartmentalization include acting in an isolated moment in a way that logically defies one's own moral code, or dividing one's unpleasant work duties from one's desires to relax. Its purpose is to avoid cognitive dissonance, or the mental discomfort and anxiety caused by a person having conflicting values, cognitions, emotions, beliefs, etc. within themselves.
Compartmentalization allows these conflicting ideas to co-exist by inhibiting direct or explicit acknowledgement and interaction between separate compartmentalized self-states.
Psychoanalytic views
Psychoanalysis considers that whereas isolation separates thoughts from feeling, compartmentalization separates different (incompatible) cognitions from each other. As a secondary, intellectual defense, it may be linked to rationalization. It is also related to the phenomenon of neurotic typing, whereby everything must be classified into mutually exclusive and watertight categories.
It has been said that when thinking about death people end up compartmentalizing, and they are in a mode of denial and acceptance about it, but they both have the result of making the thinking individual very passive.
Otto Kernberg has used the term "bridging interventions" for the therapist's attempts to straddle and contain contradictory and compartmentalized components of the patient's mind.
Vulnerability
Compartmentalization can be positive, negative, and integrated depending on the context and person. Compartmentalization may lead to hidden vulnerabilities related to self-organization and self-esteem in those who use it as a major defense mechanism. When a negativ
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https://en.wikipedia.org/wiki/Leptoid
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A leptoid is a type of elongated food-conducting cell like phloem in the stems of some mosses, such as the family Polytrichaceae. They surround strands of water-conducting hydroids. They have some structural and developmental similarities to the sieve elements of seedless vascular plants. At maturity they have inclined end cell walls with small pores and degenerate nuclei. The conduction cells of mosses, leptoids and hydroids, appear similar to those of fossil protracheophytes. However they're not thought to represent an intermediate stage in the evolution of plant vascular tissues but to have had an independent evolutionary origin.
See also
Hydroid, a related water-transporting cell analogous the xylem of vascular plants
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https://en.wikipedia.org/wiki/Microfold%20cell
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Microfold cells (or M cells) are found in the gut-associated lymphoid tissue (GALT) of the Peyer's patches in the small intestine, and in the mucosa-associated lymphoid tissue (MALT) of other parts of the gastrointestinal tract. These cells are known to initiate mucosal immunity responses on the apical membrane of the M cells and allow for transport of microbes and particles across the epithelial cell layer from the gut lumen to the lamina propria where interactions with immune cells can take place.
Unlike their neighbor cells, M cells have the unique ability to take up antigen from the lumen of the small intestine via endocytosis, phagocytosis, or transcytosis. Antigens are delivered to antigen-presenting cells, such as dendritic cells, and B lymphocytes. M cells express the protease cathepsin E, similar to other antigen-presenting cells. This process takes place in a unique pocket-like structure on their basolateral side. Antigens are recognized via expression of cell surface receptors such as glycoprotein-2 (GP2) that detect and specifically bind to bacteria. Cellular prion protein (PrP) is another example of a cell surface receptor on M cells.
M cells lack microvilli but, like other epithelial cells, they are characterized by strong cell junctions. This provides a physical barrier that constitutes an important line of defense between the gut contents and the immune system of the host. Despite the epithelial barrier, some antigens are able to infiltrate the M cell barrier and infect the nearby epithelial cells or enter the gut.
Structure
M cells are distinguished from other intestinal epithelial cells by their morphological differences. They are characterized by their short microvilli or lack of these protrusions on the cell surface. When they present microvilli, they are short, irregular, and present on the apical surface or pocket-like invagination on the basolateral surface of these cells. When they lack microvilli, they are characterized by their microfol
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https://en.wikipedia.org/wiki/Swainsonine
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Swainsonine is an indolizidine alkaloid. It is a potent inhibitor of Golgi alpha-mannosidase II, an immunomodulator, and a potential chemotherapy drug. As a toxin in locoweed (likely its primary toxin) it also is a significant cause of economic losses in livestock industries, particularly in North America. It was first isolated from Swainsona canescens.
Pharmacology
Swainsonine inhibits glycoside hydrolases, specifically N-linked glycosylation. Disruption of Golgi alpha-mannosidase II with swainsonine induces hybrid-type glycans. These glycans have a Man5GlcNAc2 core with processing on the 3-arm that resembles so-called complex-type glycans.
The pharmacological properties of this product have not been fully investigated.
Sources
Some plants do not produce the toxic compound itself; they are host of endophytic fungi which produces swainsonine.
Biosynthesis
The biosynthesis of swainsonine has been investigated in the fungus Rhizoctonia leguminicola, and it initially involves the conversion of lysine into pipecolic acid. The pyrrolidine ring is then formed via retention of the carbon atom of the pipecolate's carboxyl group, as well as the coupling of two more carbon atoms from either acetate or malonate to form a pipecolylacetate. The retention of the carboxyl carbon is striking, since it is normally lost in the biosynthesis of most other alkaloids.
The resulting oxoindolizidine is then reduced to (1R,8aS)- 1-hydroxyindolizidine, which is subsequently hydroxylated at the C2 carbon atom to yield 1,2-dihydroxyindolizidine. Finally, an 8-hydroxyl group is introduced through epimerization at C-8a to yield swainsonine. Schneider et al. have suggested that oxidation occurs at C-8a to give an iminium ion. Reduction from the β face would then yield the R configuration of swainsonine, as opposed to the S configuration of slaframine, another indolizidine alkaloid whose biosynthesis is similar to that of swainsonine during the first half of the pathway and also shown
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https://en.wikipedia.org/wiki/Telmac%20TMC-600
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The Telmac TMC-600 was a Finnish microcomputer introduced in 1982 by Telercas Oy, a Finnish importer of RCA microchips.
Only 600 units were produced, making it very rare today. The TMC-600 was the only commercially available BASIC-based home computer designed and manufactured in Finland.
Specifications
RCA 1802A (COSMAC) CPU at 3,579 MHz
Cassette tape interface (DIN-5)
VIS (Video Interface System): CDP1869 and CDP1870 companion ICs
8 kB RAM (expandable to 30 kB) and 1.5 KB of video RAM
80 × 72 pixels graphical display resolution
40 x 24 character display resolution
CDP1869 one channel sound
Telercas SBASIC
Ports: TV RF, composite video (DIN-5), Centronics, expansion
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https://en.wikipedia.org/wiki/Frequency%20domain%20sensor
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Frequency domain (FD) sensor is an instrument developed for measuring soil moisture content. The instrument has an oscillating circuit, the sensing part of the sensor is embedded in the soil, and the operating frequency will depend on the value of soil's dielectric constant.
Types of sensors
Capacitance probe, or fringe capacitance sensor. Capacitance probes use capacitance to measure the dielectric permittivity of the soil. The volume of water in the total volume of soil most heavily influences the dielectric permittivity of the soil because the dielectric constant of water (80) is much greater than the other constituents of the soil (mineral soil: 4, organic matter: 4, air: 1). Thus, when the amount of water changes in the soil, the probe will measure a change in capacitance (from the change in dielectric permittivity) that can be directly correlated with a change in water content. Circuitry inside some commercial probes change the capacitance measurement into a proportional millivolt output. Other configuration are like the neutron probe where an access tube made of PVC is installed in the soil. The probe consists of sensing head at fixed depth. The sensing head consists of an oscillator circuit, the frequency is determined by an annular electrode, fringe-effect capacitor, and the dielectric constant of the soil.
Electrical impedance sensor, which consists of soil probes and using electrical impedance measurement. The most common configuration is based on the standing wave principle (Gaskin & Miller, 1996). The device comprises a 100 MHz sinusoidal oscillator, a fixed impedance coaxial transmission line, and probe wires which is buried in the soil. The oscillator signal is propagated along the transmission line into the soil probe, and if the probe's impedance differs from that of the transmission line, a proportion of the incident signal is reflected back along the line towards the signal source.
Benefits and limitations
Compared to time domain reflect
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https://en.wikipedia.org/wiki/Apical%20ectodermal%20ridge
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The apical ectodermal ridge (AER) is a structure that forms from the ectodermal cells at the distal end of each limb bud and acts as a major signaling center to ensure proper development of a limb. After the limb bud induces AER formation, the AER and limb mesenchyme—including the zone of polarizing activity (ZPA)—continue to communicate with each other to direct further limb development.
The position of the limb bud, and hence the AER, is specified by the expression boundaries of Hox genes in the embryonic trunk. At these positions, the induction of cell outgrowth is thought to be mediated by a positive feedback loop of fibroblast growth factors (FGFs) between the intermediate mesoderm, the lateral plate mesoderm and the surface ectoderm. FGF8 in the intermediate mesoderm signals to the lateral mesoderm, restricting the expression of FGF10 through intermediate Wnt signals. Then, FGF10 in the lateral plate mesoderm signals to the surface ectoderm to create the AER, which expresses FGF8.
The AER is known to express FGF2, FGF4, FGF8, and FGF9, while the limb bud mesenchyme expresses FGF2 and FGF10. Embryo manipulation experiments have shown that some of these FGFs alone are sufficient for mimicking the AER.
Structure
Morphologically, the AER emerges as a thickening of the ectoderm at the distal rim of the limb bud. This distinct structure runs along the anterior-posterior axis of the limb bud and subsequently separates the dorsal side of the limb from its ventral side.
In the wing bud in chick embryos, the AER becomes anatomically distinguishable at the late stage of development 18HH (corresponding to 3 day-old embryos), when the distal ectodermal cells of the bud acquire a columnar shape distinguishing them from the cuboidal ectoderm. At stage 20HH (corresponding to 3.5 day-old embryos), the AER appears as a strip of pseudostratified epithelium which is maintained until 23-24HH (corresponding to 4-4.5 day-old embryos). Afterwards, the AER progressively decrease
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