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https://en.wikipedia.org/wiki/Gravitational-wave%20astronomy | Gravitational-wave astronomy is an emerging field of science, concerning the observations of gravitational waves (minute distortions of spacetime predicted by Albert Einstein's theory of general relativity) to collect relatively unique data and make inferences about objects such as neutron stars and black holes, events such as supernovae, and processes including those of the early universe shortly after the Big Bang.
Introduction
Gravitational waves are waves of the intensity of gravity generated by the accelerated masses of an orbital binary system that propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1893 and then later by Henri Poincaré in 1905 as waves similar to electromagnetic waves but the gravitational equivalent.
Gravitational waves were later predicted in 1916 by Albert Einstein on the basis of his general theory of relativity as ripples in spacetime. Later he refused to accept gravitational waves. Gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation. Newton's law of universal gravitation, part of classical mechanics, does not provide for their existence, since that law is predicated on the assumption that physical interactions propagate instantaneously (at infinite speed) – showing one of the ways the methods of Newtonian physics are unable to explain phenomena associated with relativity.
The first indirect evidence for the existence of gravitational waves came in 1974 from the observed orbital decay of the Hulse–Taylor binary pulsar, which matched the decay predicted by general relativity as energy is lost to gravitational radiation. In 1993, Russell A. Hulse and Joseph Hooton Taylor Jr. received the Nobel Prize in Physics for this discovery.
Direct observation of gravitational waves was not made until 2015, when a signal generated by the merger of two black holes was received by the LIGO gravitational wave de |
https://en.wikipedia.org/wiki/Anomaly%20matching%20condition | In quantum field theory, the anomaly matching condition by Gerard 't Hooft states that the calculation of any chiral anomaly for the flavor symmetry must not depend on what scale is chosen for the calculation if it is done by using the degrees of freedom of the theory at some energy scale. It is also known as the 't Hooft condition and the 't Hooft UV-IR anomaly matching condition.
't Hooft anomalies
There are two closely related but different types of obstructions to formulating a quantum field theory that are both called anomalies: chiral, or Adler–Bell–Jackiw anomalies, and 't Hooft anomalies.
If we say that the symmetry of the theory has a 't Hooft anomaly, it means that the symmetry is exact as a global symmetry of the quantum theory, but there is some impediment to using it as a gauge in the theory.
As an example of a 't Hooft anomaly, we consider quantum chromodynamics with massless fermions: This is the gauge theory with massless Dirac fermions. This theory has the global symmetry , which is often called the flavor symmetry, and this has a 't Hooft anomaly.
Anomaly matching for continuous symmetry
The anomaly matching condition by G. 't Hooft proposes that a 't Hooft anomaly of continuous symmetry can be computed both in the high-energy and low-energy degrees of freedom (“UV” and “IR”) and give the same answer.
Example
For example, consider the quantum chromodynamics with Nf massless quarks. This theory has the flavor symmetry This flavor symmetry becomes anomalous when the background gauge field is introduced. One may use either the degrees of freedom at the far low energy limit (far “IR” ) or the degrees of freedom at the far high energy limit (far “UV”) in order to calculate the anomaly. In the former case one should only consider massless fermions or Nambu–Goldstone bosons which may be composite particles, while in the latter case one should only consider the elementary fermions of the underlying short-distance theory. In both cases, the an |
https://en.wikipedia.org/wiki/Lead%20compound | A lead compound (, i.e. a "leading" compound, not to be confused with various compounds of the metallic element lead) in drug discovery is a chemical compound that has pharmacological or biological activity likely to be therapeutically useful, but may nevertheless have suboptimal structure that requires modification to fit better to the target; lead drugs offer the prospect of being followed by back-up compounds. Its chemical structure serves as a starting point for chemical modifications in order to improve potency, selectivity, or pharmacokinetic parameters. Furthermore, newly invented pharmacologically active moieties may have poor druglikeness and may require chemical modification to become drug-like enough to be tested biologically or clinically.
Terminology
Lead compounds are sometimes called developmental candidates. This is because the discovery and selection of lead compounds occurs prior to preclinical and clinical development of the candidate.
Discovering lead compounds
Discovery of a drugable target
Before lead compounds can be discovered, a suitable target for rational drug design must be selected on the basis of biological plausibility or identified through screening potential lead compounds against multiple targets. Drug libraries are often tested by high-throughput screenings (active compounds are designated as "hits") which can screen compounds for their ability to inhibit (antagonist) or stimulate (agonist) a receptor of interest as well as determine their selectivity for them.
Development of a lead compound
A lead compound may arise from a variety of different sources. Lead compounds are found by characterizing natural products, employing combinatorial chemistry, or by molecular modeling as in rational drug design. Chemicals identified as hits through high-throughput screening may also become lead compounds. Once a lead compound is selected it must undergo lead optimization, which involves making the compound more "drug-like." This is where Li |
https://en.wikipedia.org/wiki/Gayab | Gayab () () is a 2004 Indian Hindi supernatural black comedy thriller film, directed by Prawaal Raman and produced by Ram Gopal Varma. It stars Tusshar Kapoor and Antara Mali as the lead protagonists. The film was declared a below average at the box office and was remade in Tamil as Jithan.
Plot
Vishnu Prasad (Tusshar Kapoor) is an unappreciated nerd. His mother nags him and his father ignores him. He is in love with his neighbour Mohini (Antara Mali), but she already has a boyfriend - Sameer (Raman Trikha). Vishnu sees Mohini in a cafe with Sameer. As Sameer goes to get drinks, Mohini's eyes meet Vishnu's. A shy and nervous Vishnu accidentally winks at Mohini which angers Sameer into hitting him. Vishnu bursts into tears. Sad and depressed from his life he goes to a beach.
Angry at God for the life he has given him, Vishnu asks the statue to make him disappear from the world as no one likes him. When he reaches home, he discovers that God took his wish literally and turned him invisible. Excited and happy, Vishnu gets many opportunities to spy on Mohini and get her boyfriend in trouble. He realises that he cannot wear any other clothes than the ones he was wearing on the day he received the boon because those were the only clothes that turned invisible with him. When Vishnu sees his father is worried about him and also because of a nagging wife, he tells his father about his secret and calms him down. He plays the role of an invisible ghost to teach his mother a lesson. His mother gets scared thinking that the ghost is of her late father-in-law and faints. Vishnu thinks that he needs money to impress Mohini. So, he robs a bank and brings her all the cash but Mohnini is shocked and terrified. Vishnu decides to tell her everything. Mohini flies in a rage and tells Vishnu to leave her alone as she is in love with Sameer.
Alone and heartbroken, Vishnu gets drunk and wanders the streets. The media makes up incredible stories after the bank robbery done by an "invis |
https://en.wikipedia.org/wiki/Smart%20card%20application%20protocol%20data%20unit | In the context of smart cards, an application protocol data unit (APDU) is the communication unit between a smart card reader and a smart card. The structure of the APDU is defined by ISO/IEC 7816-4 Organization, security and commands for interchange.
APDU message command-response pair
There are two categories of APDUs: command APDUs and response APDUs. A command APDU is sent by the reader to the card – it contains a mandatory 4-byte header (CLA, INS, P1, P2) and from 0 to 65 535 bytes of data. A response APDU is sent by the card to the reader – it contains from 0 to 65 536 bytes of data, and 2 mandatory status bytes (SW1, SW2). |
https://en.wikipedia.org/wiki/Injury%20prevention | Injury prevention is an effort to prevent or reduce the severity of bodily injuries caused by external mechanisms, such as accidents, before they occur. Injury prevention is a component of safety and public health, and its goal is to improve the health of the population by preventing injuries and hence improving quality of life. Among laypersons, the term "accidental injury" is often used. However, "accidental" implies the causes of injuries are random in nature. Researchers prefer the term "unintentional injury" to refer to injuries that are nonvolitional but often preventable. Data from the U.S. Centers for Disease Control show that unintentional injuries are a significant public health concern: they are by far the leading cause of death from ages 1 through 44. During these years, unintentional injuries account for more deaths than the next three leading causes of death combined. Unintentional injuries also account for the top ten sources of nonfatal emergency room visits for persons up to age 9 and nine of the top ten sources of nonfatal emergency room visits for persons over the age of 9.
Injury prevention strategies cover a variety of approaches, many of which are classified as falling under the "3 Es" of injury prevention: education, engineering modifications, and enforcement/enactment of policies. Some organizations and researchers have variously proposed the addition of equity, empowerment, emotion, empathy, evaluation, and economic incentives to this list.
Measuring effectiveness
Injury prevention research can be challenging because the usual outcome of interest is deaths or injuries prevented and it is difficult to measure how many people did not get hurt who otherwise would have. Education efforts can be measured by changes in knowledge, attitudes, and beliefs and behaviors before and after an intervention; however, tying these changes back into reductions in morbidity and mortality is often problematic. Effectiveness of injury prevention interven |
https://en.wikipedia.org/wiki/Biomimetic%20material | Biomimetic materials are materials developed using inspiration from nature. This may be useful in the design of composite materials. Natural structures have inspired and innovated human creations. Notable examples of these natural structures include: honeycomb structure of the beehive, strength of spider silks, bird flight mechanics, and shark skin water repellency. The etymological roots of the neologism "biomimetic" derive from Greek, since means "life" and means "imitative".
Tissue engineering
Biomimetic materials in tissue engineering are materials that have been designed such that they elicit specified cellular responses mediated by interactions with scaffold-tethered peptides from extracellular matrix (ECM) proteins; essentially, the incorporation of cell-binding peptides into biomaterials via chemical or physical modification. Amino acids located within the peptides are used as building blocks by other biological structures. These peptides are often referred to as "self-assembling peptides", since they can be modified to contain biologically active motifs. This allows them to replicate information derived from tissue and to reproduce the same information independently. Thus, these peptides act as building blocks capable of conducting multiple biochemical activities, including tissue engineering. Tissue engineering research currently being performed on both short chain and long chain peptides is still in early stages.
Such peptides include both native long chains of ECM proteins as well as short peptide sequences derived from intact ECM proteins. The idea is that the biomimetic material will mimic some of the roles that an ECM plays in neural tissue. In addition to promoting cellular growth and mobilization, the incorporated peptides could also mediate by specific protease enzymes or initiate cellular responses not present in a local native tissue.
In the beginning, long chains of ECM proteins including fibronectin (FN), vitronectin (VN), and laminin (LN) |
https://en.wikipedia.org/wiki/Nerve%20guidance%20conduit | A nerve guidance conduit (also referred to as an artificial nerve conduit or artificial nerve graft, as opposed to an autograft) is an artificial means of guiding axonal regrowth to facilitate nerve regeneration and is one of several clinical treatments for nerve injuries. When direct suturing of the two stumps of a severed nerve cannot be accomplished without tension, the standard clinical treatment for peripheral nerve injuries is autologous nerve grafting. Due to the limited availability of donor tissue and functional recovery in autologous nerve grafting, neural tissue engineering research has focused on the development of bioartificial nerve guidance conduits as an alternative treatment, especially for large defects. Similar techniques are also being explored for nerve repair in the spinal cord but nerve regeneration in the central nervous system poses a greater challenge because its axons do not regenerate appreciably in their native environment.
The creation of artificial conduits is also known as entubulation because the nerve ends and intervening gap are enclosed within a tube composed of biological or synthetic materials. Whether the conduit is in the form of a biologic tube, synthetic tube or tissue-engineered conduit, it should facilitate neurotropic and neurotrophic communication between the proximal and distal ends of the nerve gap, block external inhibitory factors, and provide a physical guidance for axonal regrowth. The most basic objective of a nerve guidance conduit is to combine physical, chemical, and biological cues under conditions that will foster tissue formation.
Materials that have been used to make biologic tubes include blood vessels and skeletal muscles, while nonabsorbable and bioabsorbable synthetic tubes have been made from silicone and polyglycolide respectively. Tissue-engineered nerve guidance conduits are a combination of many elements: scaffold structure, scaffold material, cellular therapies, neurotrophic factors and biomimet |
https://en.wikipedia.org/wiki/Tinguiririca%20fauna | The fossil Tinguiririca fauna, entombed in volcanic mudflows and ash layers at the onset of the Oligocene, about 33-31.5 million years ago, represents a unique snapshot of the history of South America's endemic fauna, which was extinguished when the former island continent was joined to North America by the rising Isthmus of Panama. The fossil-bearing sedimentary layers of the Abanico Formation were first discovered in the valley of the Tinguiririca River, high in the Andes of central Chile. The faunal assemblage lends its name to the Tinguirirican stage in the South American land mammal age (SALMA) classification.
Description
The endemic fauna bridges a massive gap in the history of those mammals that were unique to South America. Paleontologists knew the earlier sloth and anteater forebears of 40 mya, but no fossils from this previously poorly sampled transitional age had been seen. Fossils of the Tinguiririca fauna include the chinchilla-like earliest rodents discovered in South America, a wide range of the hoofed herbivores called notoungulates, a shrew-like marsupial and ancestors of today's sloth and armadillos. Many of the herbivores have teeth adapted to grass-eating; though no plant fossils have been recovered, the high-crowned hypsodont teeth, protected by tough enamel well below the gumline, identifies grazers suited to a gritty diet. "The proportion of hypsodont taxa relative to other dental types generally increases with the amount of open habitat," John Flynn explained in Scientific American (May 2007) "and the Tinguiririca level of hysodonty surpasses even that observed for mammals living in modern, open habitats such as the Great Plains of North America." Statistical analyses of the number of species categorized by body size ("cenogram" analysis, an aspect of body size scaling) and of their broad ecological niches ("macroniche" analysis) bears out the existence of dry grasslands. Previously, no grassland ecosystem anywhere had been identified prior |
https://en.wikipedia.org/wiki/Clasp-knife%20response | Clasp-knife response refers to a Golgi tendon reflex with a rapid decrease in resistance when attempting to flex a joint, usually during a neurological examination. It is one of the characteristic responses of an upper motor neuron lesion. It gets its name from the resemblance between the motion of the limb and the sudden closing of a claspknife after sufficient pressure is applied.
Cause
When a joint is passively flexed, the resisting force comes from the stretch reflex (or sometimes called tendon reflex) resulting from the extensor muscle being stretched. In upper motor neuron lesions, muscle tonus may increase and resistance of muscle to stretch increases. However, if sufficient force is applied, limb resistance suddenly decreases, presumably mediated by the Golgi tendon reflex (also call autogenic inhibition).
Mechanism
This reflex is observed in patients with upper motor neuron lesions. It was frequently attributed to the action of the golgi tendon organ, likely because of early studies showing that tendon organs are activated by strong muscle stretch and inhibit motor neurons of the stretched muscle. It was thought that this was a protective reflex, preventing application of so much force that muscles become damaged. More recent work strongly suggests that tendon organs are not involved in the clasp knife reflex, but that other sensory receptors in muscles are responsible.
Example
Passive flexion of elbow meets immediate resistance due to stretch reflex in the triceps muscle. Further stretch activates inverse stretch reflex. The resistance to flexion suddenly collapses, and the elbow flexes. Continued passive flexion stretches the muscle and the sequence may be repeated.
As the muscle tone increases, resistance against flexion of the limb increases as well. However, when flexion is continued, further stretching of the triceps muscle activates an inverse stretch reflex that relaxes the muscle due to autogenic inhibition.
See also
Hypertonia |
https://en.wikipedia.org/wiki/Michel%20Talagrand | Michel Pierre Talagrand (born 15 February 1952) is a French mathematician. Docteur ès sciences since 1977, he has been, since 1985, Directeur de Recherches at CNRS and a member of the Functional Analysis Team of the Institut de Mathématique of Paris. Talagrand was elected as correspondent of the Académie des sciences of Paris in March 1997, and then as a full member in November 2004, in the Mathematics section.
Talagrand studies mainly functional analysis and probability theory and their applications.
Scientific activity
Talagrand has been interested in probability with minimal structure. He has obtained a complete characterization of bounded Gaussian processes in very general settings, and also new methods
to bound stochastic processes. He discovered new aspects of the isoperimetric and concentration of measure phenomena for product spaces, by obtaining inequalities which make use of new kind of distances between a point and a subset of a product space. These inequalities show in great generality that a random quantity which depends on many independent variables, without depending too much on one of them, does have only small fluctuations. These inequalities helped to solve most classical problems in probability theory on Banach spaces, and have also transformed the abstract theory of stochastic processes. These inequalities have been successfully used in many applications involving stochastic quantities, like for instance in statistical mechanics (disordered systems), theoretical computer science,
random matrices, and statistics (empirical processes).
The recent works of Talagrand concern spin glasses mean fields models. His objective is to give a mathematical foundation to numerous remarkable works of physicists in this domain. Talagrand showed for instance recently the validity of the Parisi formula.
Awards
Peccot-Vimont Prize of the French Collège de France (1980)
Servant Prize of the French Académie des sciences (1985)
Invited Speaker to the Internation |
https://en.wikipedia.org/wiki/Named%20data%20networking | Named Data Networking (NDN) (related to content-centric networking (CCN), content-based networking, data-oriented networking or information-centric networking (ICN)) is a proposed Future Internet architecture inspired by years of empirical research into network usage and a growing awareness of unsolved problems in contemporary internet architectures like IP. NDN has its roots in an earlier project, Content-Centric Networking (CCN), which Van Jacobson first publicly presented in 2006. The NDN project is investigating Jacobson's proposed evolution from today's host-centric network architecture IP to a data-centric network architecture (NDN). The belief is that this conceptually simple shift will have far-reaching implications for how people design, develop, deploy, and use networks and applications.
NDN has three core concepts that distinguish NDN from other network architectures. First, applications name data and data names will directly be used in network packet forwarding; consumer applications request desired data by its name, so communications in NDN are consumer-driven. Second, NDN communications are secured in a data-centric manner, that is, each piece of data (called a Data packet) will be cryptographically signed by its producer and sensitive payload or name components can also be encrypted for the purpose of privacy; in this way, consumers can verify the packet regardless of how the packet is fetched. Third, NDN adopts a stateful forwarding plane where forwarders will keep a state for each data request (called an Interest packet) and erase the state when a corresponding Data packet comes back; NDN's stateful forwarding allows intelligent forwarding strategies and eliminates loops.
Its premise is that the Internet is primarily used as an information distribution network, which is not a good match for IP, and that the future Internet's "thin waist" should be based on named data rather than numerically addressed hosts. The underlying principle is that a comm |
https://en.wikipedia.org/wiki/Amalgamation%20property | In the mathematical field of model theory, the amalgamation property is a property of collections of structures that guarantees, under certain conditions, that two structures in the collection can be regarded as substructures of a larger one.
This property plays a crucial role in Fraïssé's theorem, which characterises classes of finite structures that arise as
ages of countable homogeneous structures.
The diagram of the amalgamation property appears in many areas of mathematical logic. Examples include in modal logic as an incestual accessibility relation, and in lambda calculus as a manner of reduction having the Church–Rosser property.
Definition
An amalgam can be formally defined as a 5-tuple (A,f,B,g,C) such that A,B,C are structures having the same signature, and f: A → B, g: A → C are embeddings. Recall that f: A → B is an embedding if f is an injective morphism which induces an isomorphism from A to the substructure f(A) of B.
A class K of structures has the amalgamation property if for every amalgam with A,B,C ∈ K and A ≠ Ø, there exist both a structure D ∈ K and embeddings f': B → D, g': C → D such that
A first-order theory has the amalgamation property if the class of models of has the amalgamation property. The amalgamation property has certain connections to the quantifier elimination.
In general, the amalgamation property can be considered for a category with a specified choice of the class of morphisms (in place of embeddings). This notion is related to the categorical notion of a pullback, in particular, in connection with the strong amalgamation property (see below).
Examples
The class of sets, where the embeddings are injective functions, and if they are assumed to be inclusions then an amalgam is simply the union of the two sets.
The class of free groups where the embeddings are injective homomorphisms, and (assuming they are inclusions) an amalgam is the quotient group , where * is the free product.
The class of finite linear orderings |
https://en.wikipedia.org/wiki/Notice%20and%20notice | A "notice and notice" system is used by some internet service providers (ISPs) in relation to the uploading and downloading activities of a user of a peer-to-peer file sharing network, otherwise known as "P2P". It may occur when an ISP receives notification from a rights holder to a copyrighted work that one of its subscribers is allegedly hosting or sharing infringing material. The ISP may then be required to forward the notice to the subscriber, and to monitor that subscriber's activities for a period of time. The ISP is not required to reveal the subscriber's personal information, nor does the ISP take any further steps to ensure that the allegedly infringing material is removed.
It is used primarily in Canada, where copyright legislation permits the download of copyrighted material, but makes it illegal to upload the same material. This was legislated with bill C-60 in 2005.
In contrast with the Notice and Takedown system in American law, Notice and Notice attempts to protect both parties' interests. This helps to ensure that non-infringing material is not removed under the guise of copyright protection. |
https://en.wikipedia.org/wiki/Ascofuranone | Ascofuranone is an antibiotic produced by various ascomycete fungi including Acremonium sclerotigenum that inhibits the Trypanosoma brucei alternative oxidase and is a lead compound in efforts to produce other drugs targeting this enzyme for the treatment of sleeping sickness. The compound is effective both in vitro cell culture and in infections in mice.
Ascofuranone has also been reported to have anti-tumor activity, and modulate the immune system.
Biosynthesis
The proposed biosynthesis of ascofuranone was reported by Kita et al., as well as by Abe et al. The prenylation of orsellinic acid, followed by terminal cyclization through epoxidation is how ascofuranone can be synthesized. Compound (1), ilicicolinic acid B, was found to be produced from polyketide synthase (PKS) StBA and that AscCABD are responsible for the biosynthesis of ilicicolin A (3). Ilicicolin B (2) was found to be produced by expressing AscC (polyketide synthase) which is then followed by expression of AscA (prenyltransferase). AscD (flavin-dependent halogenase, flavin binding enzyme) is able to catalyze the chlorination of ilicicolinic acid B (2) to yield ilicicolin A (3).
Expodiation of (3) by AscE (P450 monooxygenase) leads to the formation of ilicicolin A epoxide (4). Ilicicolin A epoxide can then be hydroxylated by AscH at C-16 (P450 monooygenase) to yield intermediate (5) which can then be cyclized by AscI (eight-transmembrane protein, TPC) into ascofuranol (6), specifically through 6-endo-tet cyclization. Finally, ascofuranol (6) can be oxidized by AscJ (NAD(P)-dependent alcohol dehydrogenase) leading to the formation of ascofuranone. |
https://en.wikipedia.org/wiki/Enzootic | Enzootic is the non-human equivalent of endemic and means, in a broad sense, "belonging to" or "native to", "characteristic of", or "prevalent in" a particular geography, race, field, area, or environment; native to an area or scope.
It also has two specific meanings:
an organism being "enzootic" means native to a place or a specific fauna
in epizoology, an infection is said to be "enzootic" in a population when the infection is maintained in the population without the need for external inputs (cf. Endemic).
See also
Epizootic
Biodiversity |
https://en.wikipedia.org/wiki/Asymmetric%20bacterium | Asymmetric bacteria are bacteria that undergo "non-symmetrical" life cycles. This especially includes those that differentiate temporally, such as prosthecate bacteria.
History
Cell division asymmetries have appeared alongside the evolution of complex developmental processes. While bacteria were historically considered symmetric simple cells, this idea has been overturned by novel technology and observation techniques. However, asymmetric bacteria remain difficult to detect. Asymmetrical growth aids in determining the age of bacteria, because it gives rise to an old pole, or region of inert cell wall material found at the ends of a rod-shaped bacterial cell. Following the "old pole" of the cell wall material allows an observer to create a bacterial lineage.
Types of asymmetry
Bacteria exhibit three different types of asymmetry: conditional asymmetry, reproductive asymmetry, and morphological asymmetry.
Conditional asymmetry is well defined in the case of endospore formation, which is triggered by stressful environmental conditions such as increased heat, pH change, and nutrient depletion. This type of asymmetry is usually seen in Bacilli and Clostridia.
Reproductive asymmetry is classically linked to bacterial budding, where a mother cell concentrates cell wall material to one area and a daughter cell begins to bud from that thickening. Cell growth which gives rise to reproductive asymmetry occurs in three phases: stalk elongation, daughter cell elongation, and septum formation.
Morphological asymmetry is classified by polar elongation. In this type of asymmetrical growth, the daughter cell receives most of the new cell wall material.
Examples
Bacillus subtilis
Caulobacter crescentus |
https://en.wikipedia.org/wiki/Routing%20Assets%20Database | The Routing Assets Database (RADb), formerly known as the Routing Arbiter Database is a public database in which the operators of Internet networks publish authoritative declarations of routing policy for their Autonomous System (AS) which are, in turn, used by the operators of other Internet networks to configure their inbound routing policy filters. The RADb, operated by the University of Michigan's Merit Network, was the first such database, but others followed in its wake, forming a loose confederation of Internet routing registries, containing sometimes-overlapping, and sometimes-conflicting, routing policy data, expressed in Routing Policy Specification Language (RPSL) syntax.
History
The RADb was developed in the early 1990s as part of the National Science Foundation (NSF)-funded Routing Arbiter Project. The Routing Policy Specification Language was subsequently retroactively formalized in RFC 2280, in January, 1998.
Usage
Historically, most larger Internet service providers, and all within the European RIPE NCC region require customers to be registered in an Internet Routing Registry prior to propagating BGP announcements of their routes. This has not been a rigorously-enforced operational standard, however, and has declined since a peak in the early 2000s.
Security
The Internet Routing Registry system is an artifact of the 1990s era of the Internet, as the Internet's economy and governance were in transition from an academic mode to a commercial mode, and predate the era of ubiquitous cryptography. The RADb initially relied upon a trust model, in which write access to the database was not strictly controlled. A write-permissions access model was subsequently added, in which individuals or roles representing each Autonomous System had authority to write records related to that AS, including which IP address blocks it would originate routing advertisements for, and which other Autonomous Systems were allowed to advertise transit routing paths to it. Th |
https://en.wikipedia.org/wiki/Integro-differential%20equation | In mathematics, an integro-differential equation is an equation that involves both integrals and derivatives of a function.
General first order linear equations
The general first-order, linear (only with respect to the term involving derivative) integro-differential equation is of the form
As is typical with differential equations, obtaining a closed-form solution can often be difficult. In the relatively few cases where a solution can be found, it is often by some kind of integral transform, where the problem is first transformed into an algebraic setting. In such situations, the solution of the problem may be derived by applying the inverse transform to the solution of this algebraic equation.
Example
Consider the following second-order problem,
where
is the Heaviside step function. The Laplace transform is defined by,
Upon taking term-by-term Laplace transforms, and utilising the rules for derivatives and integrals, the integro-differential equation is converted into the following algebraic equation,
Thus,
.
Inverting the Laplace transform using contour integral methods then gives
.
Alternatively, one can complete the square and use a table of Laplace transforms ("exponentially decaying sine wave") or recall from memory to proceed:
.
Applications
Integro-differential equations model many situations from science and engineering, such as in circuit analysis. By Kirchhoff's second law, the net voltage drop across a closed loop equals the voltage impressed . (It is essentially an application of energy conservation.) An RLC circuit therefore obeys
where is the current as a function of time, is the resistance, the inductance, and the capacitance.
The activity of interacting inhibitory and excitatory neurons can be described by a system of integro-differential equations, see for example the Wilson-Cowan model.
The Whitham equation is used to model nonlinear dispersive waves in fluid dynamics.
Epidemiology
Integro-differential equations ha |
https://en.wikipedia.org/wiki/Prosthecate%20bacteria | Prosthecate bacteria are a non-phylogenetically related group of Gram-negative bacteria that possess appendages, termed prosthecae. These cellular appendages are neither pili nor flagella, as they are extensions of the cellular membrane and contain cytosol. One notable group of prosthecates is the genus Caulobacter.
Function of prostheca
Prosthecates are generally chemoorganotrophic aerobes that can grow in nutrient-poor habitats, being able to survive at nutrient levels on the order of parts-per-million for which reason they are often found in aquatic habitats. These bacteria will attach to surfaces with their prosthecae, allowing a greater surface area with which to take up nutrients (and release waste products). Some prosthecates will grow in nutrient-poor soils as aerobic heterotrophs.
See also
Caulobacter
Oligotrophic
Flagella
Pilus
External links
Poindexter, Jeanne S. Dimorphic Prosthecate Bacteria: The Genera Caulobacter, Asticcacaulis, Hyphomicrobium, Pedomicrobium, Hyphomonas and Thiodendron. |
https://en.wikipedia.org/wiki/Static%20light%20scattering | Static light scattering is a technique in physical chemistry that measures the intensity of the scattered light to obtain the average molecular weight Mw of a macromolecule like a polymer or a protein in solution. Measurement of the scattering intensity at many angles allows calculation of the root mean square radius, also called the radius of gyration Rg. By measuring the scattering intensity for many samples of various concentrations, the second virial coefficient, A2, can be calculated.
Static light scattering is also commonly utilized to determine the size of particle suspensions in the sub-μm and supra-μm ranges, via the Lorenz-Mie (see Mie scattering) and Fraunhofer diffraction formalisms, respectively.
For static light scattering experiments, a high-intensity monochromatic light, usually a laser, is launched into a solution containing the macromolecules. One or many detectors are used to measure the scattering intensity at one or many angles. The angular dependence is required to obtain accurate measurements of both molar mass and size for all macromolecules of radius above 1–2% of the incident wavelength. Hence simultaneous measurements at several angles relative to the direction of the incident light, known as multi-angle light scattering (MALS) or multi-angle laser light scattering (MALLS), are generally regarded as the standard implementation of static light scattering. Additional details on the history and theory of MALS may be found in multi-angle light scattering.
To measure the average molecular weight directly without calibration from the light scattering intensity, the laser intensity, the quantum efficiency of the detector, and the full scattering volume and solid angle of the detector need to be known. Since this is impractical, all commercial instruments are calibrated using a strong, known scatterer like toluene since the Rayleigh ratio of toluene and a few other solvents were measured using an absolute light scattering instrument.
Theory
Fo |
https://en.wikipedia.org/wiki/Branch%20trace | Branch trace is a computer program debugging tool or analysis technique. It is an abbreviated instruction trace in which only the successful branch instructions are recorded. On IBM System/360 this was implemented as part of Program-Event Recording (PER) but was seldom used at the application programming level. Program Event Recording hardware was used and due to the overhead of this tool, it was removed from customer-available MVS systems.
Branch tracing is also available for Pentium 4, Xeon and later Intel processors. There are dedicated processor commands to enable branch tracing and save executed branches into special Intel Branch Trace Store (BTS) area of resident memory. The Branch Trace Store can be also configured to be a circular buffer, so that last executed branches are recorded. Branch tracing on Intel processors using the Branch Trace Store can cause 40x application run-time slow down. For the Intel Core M and the 5th Generation of Intel Processors, Intel PT (Processor Trace) has been introduced, which aims to provide a full control flow trace. Intel PT is said to have only a minimum impact on the program's execution (< 5%).
Use
With the availability and reference to a compiler listing of the program together with a branch trace, the full path of executed instructions can be reconstructed. With a lot more effort, the full path can even be reconstructed with a memory dump (containing the program storage) and a branch trace.
Alternatives
A more comprehensive trace of all the instructions (including instructions between branches) can be obtained by the use of an instruction set simulator (where available on some platforms). A full instruction trace can provide additional information such as address/length and value of memory alterations.
See also
Basic block
Instruction set simulator
Program animation
Trace cache |
https://en.wikipedia.org/wiki/List%20of%20Italian%20flags | This is a list of flags used in Italy. For more information about the national flag, visit the article Flag of Italy.
National flags
Military flags
Army rank flags
Naval rank flags
Standards
Historical flags
Roman Empire Vexilloids
Preunification era
Napoleonic era
Unification and Kingdom of Italy
Italian Republic
Regional flags
Official regional flags
Ordinary regions
Autonomous regions
Flags of historical and cultural regions
Proposed regional flags
Provincial flags
Municipal flags
Political flags
Ethnic groups flags
House flags
Citations |
https://en.wikipedia.org/wiki/Skin%20flora | Skin flora, also called skin microbiota, refers to microbiota (communities of microorganisms) that reside on the skin, typically human skin.
Many of them are bacteria of which there are around 1,000 species upon human skin from nineteen phyla. Most are found in the superficial layers of the epidermis and the upper parts of hair follicles.
Skin flora is usually non-pathogenic, and either commensal (are not harmful to their host) or mutualistic (offer a benefit). The benefits bacteria can offer include preventing transient pathogenic organisms from colonizing the skin surface, either by competing for nutrients, secreting chemicals against them, or stimulating the skin's immune system. However, resident microbes can cause skin diseases and enter the blood system, creating life-threatening diseases, particularly in immunosuppressed people.
A major non-human skin flora is Batrachochytrium dendrobatidis, a chytrid and non-hyphal zoosporic fungus that causes chytridiomycosis, an infectious disease thought to be responsible for the decline in amphibian populations.
Species variety
Bacteria
The estimate of the number of species present on skin bacteria has been radically changed by the use of 16S ribosomal RNA to identify bacterial species present on skin samples direct from their genetic material. Previously such identification had depended upon microbiological culture upon which many varieties of bacteria did not grow and so were hidden to science.
Staphylococcus epidermidis and Staphylococcus aureus were thought from cultural based research to be dominant. However 16S ribosomal RNA research finds that while common, these species make up only 5% of skin bacteria. However, skin variety provides a rich and diverse habitat for bacteria. Most come from four phyla: Actinomycetota (51.8%), Bacillota (24.4%), Pseudomonadota (16.5%), and Bacteroidota (6.3%).
There are three main ecological areas: sebaceous, moist, and dry. Propionibacteria and Staphylococci species were t |
https://en.wikipedia.org/wiki/Protocol%20converter | A protocol converter is a device used to convert standard or proprietary protocol of one device to the protocol suitable for the other device or tools to achieve the desired interoperability. Protocols are software installed on the routers, which convert the data formats, data rate and protocols of one network into the protocols of the network in which data is navigating. There are varieties of protocols used in different fields like power generation, transmission and distribution, oil and gas, automation, utilities, and remote monitoring applications. The major protocol translation messages involve conversion of data messages, events, commands, and time synchronization.
General architecture
The general architecture of a protocol converter includes an internal master protocol communicating to the external slave devices and the data collected is used to update the internal database of the converter. When the external master requests for data, the internal slave collects data from the database and send it to the external master. There will be different schemes for handling the spontaneous reporting of events and commands. There can be different physical medium for communication on protocol-X & Y, which include RS-232, RS-485, Ethernet, etc.
Applications of protocol converters
Protocol Converter applications vary from industry to industry. The protocol converter can be a software converter, hardware converter, or an integrated converter depending on the protocols.
Some of the key applications are:
Substation automation
Building automation
Process automation
The major protocols used in each area of application are listed under List of automation protocols.
Latency and engineering issues in using protocol converters
Protocol Converters are generally used for transforming data and commands from one device or application to another. This necessarily involves transformation of data, commands, their representation, encoding and framing to achieve the conversion. |
https://en.wikipedia.org/wiki/Film%20temperature | In fluid thermodynamics, the film temperature () is an approximation of the temperature of a fluid inside a convection boundary layer. It is calculated as the arithmetic mean of the temperature at the surface of the solid boundary wall () and the free-stream temperature ():
The film temperature is often used as the temperature at which fluid properties are calculated when using the Prandtl number, Nusselt number, Reynolds number or Grashof number to calculate a heat transfer coefficient, because it is a reasonable first approximation to the temperature within the convection boundary layer.
Somewhat confusing terminology may be encountered in relation to boilers and heat exchangers, where the same term is used to refer to the limit (hot) temperature of a fluid in contact with a hot surface. |
https://en.wikipedia.org/wiki/Isomorphism-closed%20subcategory | In category theory, a branch of mathematics, a subcategory of a category is said to be isomorphism closed or replete if every -isomorphism with belongs to This implies that both and belong to as well.
A subcategory that is isomorphism closed and full is called strictly full. In the case of full subcategories it is sufficient to check that every -object that is isomorphic to an -object is also an -object.
This condition is very natural. For example, in the category of topological spaces one usually studies properties that are invariant under homeomorphisms—so-called topological properties. Every topological property corresponds to a strictly full subcategory of |
https://en.wikipedia.org/wiki/Pro-oxidant | Pro-oxidants are chemicals that induce oxidative stress, either by generating reactive oxygen species or by inhibiting antioxidant systems. The oxidative stress produced by these chemicals can damage cells and tissues, for example, an overdose of the analgesic paracetamol (acetaminophen) can fatally damage the liver, partly through its production of reactive oxygen species.
Some substances can serve as either antioxidants or pro-oxidants, depending on conditions. Some of the important conditions include the concentration of the chemical and if oxygen or transition metals are present. While thermodynamically very favored, reduction of molecular oxygen or peroxide to superoxide or hydroxyl radical respectively is spin forbidden. This greatly reduces the rates of these reactions, thus allowing aerobic life to exist. As a result, the reduction of oxygen typically involves either the initial formation of singlet oxygen, or spin–orbit coupling through a reduction of a transition-series metal such as manganese, iron, or copper. This reduced metal then transfers the single electron to molecular oxygen or peroxide.
Metals
Transition metals can serve as pro-oxidants. For example, chronic manganism is a classic "pro-oxidant" disease. Another disease associated with the chronic presence of a pro-oxidant transition-series metal is hemochromatosis, associated with elevated iron levels. Similarly, Wilson's disease is associated with elevated tissue levels of copper. Such syndromes tend to be associated with common symptomology. Thus, all are occasional symptoms of (e.g) hemochromatosis, another name for which is "bronze diabetes". The pro-oxidant herbicide paraquat, Wilson's disease, and striatal iron have similarly been linked to human Parkinsonism. Paraquat also produces Parkinsonian-like symptoms in rodents.
Fibrosis
Fibrosis or scar formation is another pro-oxidant-related symptom. E.g., interocular copper or vitreous chalicosis is associated with severe vitr |
https://en.wikipedia.org/wiki/Ligand%20dependent%20pathway | There are two types of pathway for substitution of ligands in a complex. The ligand dependent pathway is the one whereby the chemical properties of the ligand affect the rate of substitution. Alternatively, there is the ligand independent pathway, which is where the ligand does not have an effect.
This is of vital importance in the world of inorganic chemistry and complex ions. |
https://en.wikipedia.org/wiki/Wooden%20ship%20model | Wooden ship models or wooden model ships are scale representations of ships, constructed mainly of wood. This type of model has been built for over two thousand years.
Basic types of wooden ship model construction
There are five basic types of construction used in building a wooden ship model hull:
Solid wood hull sawn and carved from a single block of wood.
Gluing together two thinner blocks of wood so that a block is formed with the seam vertical, so that the seam will show running down that surface of the block which is to be the deck. No advantage is gained by having the seam show along the sides of the hull.
Bread and Butter Cutting four or five thinner slabs of wood (the Bread) to be glued (the Butter) later into a laminated block. In this case, the slabs will be oriented so that they sit one on top of the other.
Plank on bulkhead, a technique in which a series of shaped bulkheads are placed along the keel to form a shaped stage which will be covered with planks to form the hull of the model.
Plank on frame In this technique, the model is built just as the full-size wooden ship is constructed. The keel is laid down in a manner which keeps it straight and true.. The sternpost and stem are erected, deadwood and strengthening pieces inserted, and a series of shaped frames are built and erected along the keel to form the internal framework of the model. The planks are then applied over the frame to form the external covering.
Scale conversion factors
Instead of using plans made specifically for models, many model shipwrights use the actual blueprints for the original vessel.
One can take drawings for the original ship to a blueprint service and have them blown up, or reduced to bring them to the new scale.
For instance, if the drawings are in 1/4" scale and you intend to build in 3/16", tell the service to reduce them 25%.
You can use the conversion table below to determine the percentage of change. You can easily work directly from the original drawings howe |
https://en.wikipedia.org/wiki/SL2%28R%29 | {{DISPLAYTITLE:SL2(R)}}
In mathematics, the special linear group SL(2, R) or SL2(R) is the group of 2 × 2 real matrices with determinant one:
It is a connected non-compact simple real Lie group of dimension 3 with applications in geometry, topology, representation theory, and physics.
SL(2, R) acts on the complex upper half-plane by fractional linear transformations. The group action factors through the quotient PSL(2, R) (the 2 × 2 projective special linear group over R). More specifically,
PSL(2, R) = SL(2, R) / {±I},
where I denotes the 2 × 2 identity matrix. It contains the modular group PSL(2, Z).
Also closely related is the 2-fold covering group, Mp(2, R), a metaplectic group (thinking of SL(2, R) as a symplectic group).
Another related group is SL±(2, R), the group of real 2 × 2 matrices with determinant ±1; this is more commonly used in the context of the modular group, however.
Descriptions
SL(2, R) is the group of all linear transformations of R2 that preserve oriented area. It is isomorphic to the symplectic group Sp(2, R) and the special unitary group SU(1, 1). It is also isomorphic to the group of unit-length coquaternions. The group SL±(2, R) preserves unoriented area: it may reverse orientation.
The quotient PSL(2, R) has several interesting descriptions, up to Lie group isomorphism:
It is the group of orientation-preserving projective transformations of the real projective line
It is the group of conformal automorphisms of the unit disc.
It is the group of orientation-preserving isometries of the hyperbolic plane.
It is the restricted Lorentz group of three-dimensional Minkowski space. Equivalently, it is isomorphic to the indefinite orthogonal group SO+(1,2). It follows that SL(2, R) is isomorphic to the spin group Spin(2,1)+.
Elements of the modular group PSL(2, Z) have additional interpretations, as do elements of the group SL(2, Z) (as linear transforms of the torus), and these interpretations can also be viewed in light of the |
https://en.wikipedia.org/wiki/LAIM%20Working%20Group | The LAIM (Log Anonymization and Information Management) Working Group is a NSF and ONR funded research group at the National Center for Supercomputing Applications under the direction of Adam Slagell . Work from this group focuses upon log anonymization and Internet privacy. The LAIM group, established in 2005, has released 3 different log anonymization tools: CANINE, Scrub-PA, and FLAIM. FLAIM is their only tool still under active development.
External links
LAIM Working Group Official Home
CANINE Home Page
Scrub-PA Home Page
Official FLAIM Home Page
CRAWDAD entry on FLAIM at Dartmouth
Anonymity
Computer security organizations
Internet privacy organizations
Privacy organizations
Organizations established in 2005 |
https://en.wikipedia.org/wiki/Polar%20wind | The polar wind or plasma fountain is a permanent outflow of plasma from the polar regions of Earth's magnetosphere, caused by the interaction between the solar wind and the Earth's atmosphere. The solar wind ionizes gas molecules in the upper atmosphere to such high energy that some of them reach escape velocity and pour into space. A considerable percentage of these ions remain bound inside Earth's magnetic field, where they form part of the radiation belts.
The term was coined in 1968 in a pair of articles by Banks and Holzer and by Ian Axford. Since the process by which the ionospheric plasma flows away from the Earth along magnetic field lines is similar to the flow of solar plasma away from the sun's corona (the solar wind), Axford suggested the term "polar wind." The idea for the polar wind originated with the desire to solve the paradox of the terrestrial helium budget. This paradox consists of the fact that helium in the Earth's atmosphere seems to be produced (via radioactive decay of uranium and thorium) faster than it is lost by escaping from the upper atmosphere. The realization that some helium could be ionized, and therefore escape the earth along open magnetic field lines near the magnetic poles (the 'polar wind'), is one possible solution to the paradox.
Further research came from the Retarding Ion Mass Spectrometer instrument on the Dynamics Explorer spacecraft, in the 1980s. Recently, the SCIFER sounding rocket was launched into the plasma heating region of the fountain. |
https://en.wikipedia.org/wiki/Arsenical | Arsenicals are chemical compounds that contain arsenic. In a military context, the term arsenical refer to toxic arsenic compounds that are used as chemical warfare agents. This include blister agents, blood agents and vomiting agents. Historically, they were used extensively as insecticides, especially lead arsenate.
Examples
Blister agents
Ethyldichloroarsine
Lewisite
Methyldichloroarsine
Phenyldichloroarsine
Blood agents
Arsine
Vomiting agents
Adamsite
Diphenylchlorarsine
Diphenylcyanoarsine
Phenyldichloroarsine |
https://en.wikipedia.org/wiki/Cape%20foot | A Cape foot is a unit of length defined as 1.0330 English feet (and equal to 12.396 English inches, or 0.31485557516 meters) found in documents of belts and diagrams relating to landed property. It was identically equal to the Rijnland voet and was introduced into South Africa by the Dutch settlers in the seventeenth and eighteenth century.
Its relationship to the English foot was clarified in 1859 by an Act of the government of the Cape Colony, South Africa. It was used for land surveying and title deeds in rural areas of South Africa apart from Natal and was also for urban surveying and title deeds in the Transvaal. There were 144 square Cape feet in one Cape rood and 600 Cape roods (86,400 square Cape feet) in one morgen.
Its use ceased when South Africa adopted the metric system in 1977, though it has not yet been entirely replaced in pre-existing title deeds. |
https://en.wikipedia.org/wiki/Naturescaping | Naturescaping (or nature scaping) is a method of landscape design and landscaping that allows people and nature to coexist with landscaping. By incorporating certain native plants into one's yard, one can attract beneficial insects, birds, and other creatures, and help keep our rivers and streams healthy.
Extensive urban growth and urban sprawl over the last century has had a significant impact on habitat that birds and other wildlife once called home. Homeowners with yards and gardens have a unique opportunity to curtail this loss of habitat by creating their own backyard wildlife garden, a wildlife sanctuary.
Origins
Naturescaping takes some of its principles from the US Environmental Protection Agency's (EPA) "GreenScaping" or "Beneficial Landscaping" programs — which strive to reduce water, energy, and chemical usage. Naturescaping is an organic discipline of this practice, that is easily adapted to backyards.
The EPA has worked together with the Department of Homeland Security to encourage energy independence and reduce needs for hazardous materials. Water and energy use in residential landscaping accounts for x% (please cite correct figure) of the total water and energy use in the country. The EPA has found that one hour of lawn mowing contributes as much smog pollution as driving 10 cars for one hour (about 650 miles).
Since the 1995 Oklahoma City federal building bombing with explosives made from fertilizer, the distribution and use of household and garden chemicals has been more closely scrutinized. By providing alternatives, their use can be reduced.
History
Most universities throughout the country, that have agricultural programs, also have university cooperative extensions. These programs include Master Gardeners. The practice of naturescaping is being taught at several of these universities.
Current acceptance
The practice has spawned many non-profit groups to form near universities teaching this practice. Many include some form of the phrase |
https://en.wikipedia.org/wiki/Chronemics | Chronemics is an anthropological, philosophical, and linguistic subdiscipline that describes how time is perceived, coded, and communicated across a given culture. It is one of several subcategories to emerge from the study of nonverbal communication. According to the Encyclopedia of Special Education, "Chronemics includes time orientation, understanding and organisation, the use of and reaction to time pressures, the innate and learned awareness of time, by physically wearing or not wearing a watch, arriving, starting, and ending late or on time." A person's perception and values placed on time plays a considerable role in their communication process. The use of time can affect lifestyles, personal relationships, and work life. Across cultures, people usually have different time perceptions, and this can result in conflicts between individuals. Time perceptions include punctuality, interactions, and willingness to wait.
Definition
Chronemics is the study of the use of time in nonverbal communication. Time perceptions include punctuality, willingness to wait, and interactions. The use of time can affect lifestyles, daily agendas, speed of speech, movements, and how long people are willing to listen.
Thomas J. Bruneau, a professor in communication at Radford University who focused his studies on nonverbal communication, interpersonal communication, and intercultural communication, coined the term "chronemics" in the late 1970s to help define the function of time in human interaction:
Time can be used as an indicator of status. For example, in most companies the boss can interrupt progress to hold an impromptu meeting in the middle of the work day, yet the average worker would have to make an appointment to see the boss.
The way in which different cultures perceive time can influence communication as well.
Monochronic time
A monochronic time system means that things are done one at a time and time is segmented into small precise units. Under this system, time |
https://en.wikipedia.org/wiki/List%20of%20U.S.%20state%20crustaceans | , seven U.S. states and the Capital city have designated state crustaceans:
Louisiana has the freshwater crawfish Procambarus clarkii.
Maryland has the blue crab, Callinectes sapidus.
Oregon has the Dungeness crab, Metacarcinus magister.
Alabama has the brown shrimp, Peneaus aztecus.
Maine has the lobster, Homarus americanus.
Texas has the Texas Gulf shrimp, Penaeus aztecus, P. setiferus, and P. duorarum.
Utah has the brine shrimp.
The District of Columbia has the Hay's Spring amphipod.
Louisiana
In 1983, the state of Louisiana designated the Louisiana crawfish, Procambarus clarkii, as their state crustacean. The native range of P. clarkii is along the Gulf Coast from northern Mexico to the Florida panhandle, as well as inland, to southern Illinois and Ohio. It is most commonly found in warm fresh water, such as slowly flowing rivers, marshes, reservoirs, irrigation systems and rice paddies. P. clarkii grows quickly, and is capable of reaching weights over , and lengths of .
Harvests of P. clarkii account for a large majority of the crawfish produced in the United States. In 1990, Louisiana produced 90% of the crawfish in the world and consumed 70% of it locally, but by 2003, Asian farms and fisheries produced more, outpacing American production rapidly. By 2018, P. clarkii crawfish production in the Americas represented just 4% of total global P. clarkii supply. However, Louisiana crawfish remain in demand locally. In 2018, 93% of crawfish farms in the US were located in Louisiana. Louisiana crawfish are usually boiled in a large pot with heavy seasoning (salt, cayenne pepper, lemon, garlic, bay leaves, etc.) and other items such as potatoes, corn on the cob, onions, garlic, and sausage. There are many differing methods used to season a crawfish boil and an equal number of opinions on which one is correct.
Maryland
The blue crab, Callinectes sapidus was chosen as the state crustacean of Maryland in 1989. C. sapidus is a crab found in the waters of the w |
https://en.wikipedia.org/wiki/History%20of%20polio | The history of polio (poliomyelitis) infections began during prehistory. Although major polio epidemics were unknown before the 20th century, the disease has caused paralysis and death for much of human history. Over millennia, polio survived quietly as an endemic pathogen until the 1900s when major epidemics began to occur in Europe. Soon after, widespread epidemics appeared in the rest of the world. By 1910, frequent epidemics became regular events throughout the developed world primarily in cities during the summer months. At its peak in the 1940s and 1950s, polio would paralyze or kill over half a million people worldwide every year.
The fear and the collective response to these epidemics would give rise to extraordinary public reaction and mobilization spurring the development of new methods to prevent and treat the disease and revolutionizing medical philanthropy. Although the development of two polio vaccines has eliminated wild poliomyelitis in all but two countries (Afghanistan and Pakistan), the legacy of poliomyelitis remains in the development of modern rehabilitation therapy and in the rise of disability rights movements worldwide.
Early history
Ancient Egyptian paintings and carvings depict otherwise healthy people with withered limbs, and children walking with canes at a young age. It is theorized that the Roman Emperor Claudius was stricken as a child, and this caused him to walk with a limp for the rest of his life. Perhaps the earliest recorded case of poliomyelitis is that of Sir Walter Scott. In 1773, Scott was said to have developed "a severe teething fever which deprived him of the power of his right leg". At the time, polio was not known to medicine. A retrospective diagnosis of polio is considered to be strong due to the detailed account Scott later made, and the resultant lameness of his right leg had an important effect on his life and writing.
The symptoms of poliomyelitis have been described by many names. In the early nineteenth cen |
https://en.wikipedia.org/wiki/Virtual%20temperature | In atmospheric thermodynamics, the virtual temperature () of a moist air parcel is the temperature at which a theoretical dry air parcel would have a total pressure and density equal to the moist parcel of air.
The virtual temperature of unsaturated moist air is always greater than the absolute air temperature, however, as the existence of suspended cloud droplets reduces the virtual temperature.
The virtual temperature effect is also known as the vapor buoyancy effect. It has been described to increase Earth's thermal emission by warming the tropical atmosphere.
Introduction
Description
In atmospheric thermodynamic processes, it is often useful to assume air parcels behave approximately adiabatically, and approximately ideally. The specific gas constant for the standardized mass of one kilogram of a particular gas is variable, and described mathematically as
where is the molar gas constant, and is the apparent molar mass of gas in kilograms per mole. The apparent molar mass of a theoretical moist parcel in Earth's atmosphere can be defined in components of water vapor and dry air as
with being partial pressure of water, dry air pressure, and and representing the molar masses of water vapor and dry air respectively. The total pressure is described by Dalton's law of partial pressures:
Purpose
Rather than carry out these calculations, it is convenient to scale another quantity within the ideal gas law to equate the pressure and density of a dry parcel to a moist parcel. The only variable quantity of the ideal gas law independent of density and pressure is temperature. This scaled quantity is known as virtual temperature, and it allows for the use of the dry-air equation of state for moist air. Temperature has an inverse proportionality to density. Thus, analytically, a higher vapor pressure would yield a lower density, which should yield a higher virtual temperature in turn.
Derivation
Consider a moist air parcel containing masses and of dr |
https://en.wikipedia.org/wiki/Pierre-Paul%20Grass%C3%A9 | Pierre-Paul Grassé (November 27, 1895 in Périgueux (Dordogne) – July 9, 1985) was a French zoologist, writer of over 300 publications including the influential 52-volume Traité de Zoologie. He was an expert on termites and one of the last proponents of neo-Lamarckian evolution.
Biography
Education
Grassé began his studies in Périgueux where his parents owned a small business. He went on to study medicine at the University of Bordeaux and studied biology in parallel, including the lectures of the entomologist Jean de Feytaud (1881–1973). Mobilized during World War I, he was forced to interrupt his studies during four years. By the end of the war he was a military surgeon.
Grassé continued his studies in Paris, focusing exclusively on science. He obtained his Licence in Biology and frequented the laboratory of biologist Étienne Rabaud (1868–1956). He abandoned his preparations for the agrégation to accept a position as professor in the École Nationale Supérieure Agronomique de Montpellier (1921), where the department of zoology was led by François Picard (1879–1939). There he frequented several phytogeographers like Charles Flahault (1852–1935), Josias Braun-Blanquet (1884–1980), Georges Kuhnholtz-Lordat (1888–1965) and Marie Louis Emberger (1897–1969). He became the assistant of Octave Duboscq (1868–1943) who oriented the young Grassé toward the study of protozoan parasites. After the departure of Duboscq to Paris, Grassé worked for Eugène Bataillon (1864–1953) and there discovered techniques for experimental embryology.
In 1926, Grassé became vice-director of the École supérieure de sériciculture. He submitted his theses, Contribution à l'étude des flagellés parasites, in 1926, and it was published in the Archives de zoologie expérimentale et générale.
Teaching and research
In 1929, Grassé became professor of zoology at the Université de Clermont-Ferrand. He supervised the theses of several students on insects. He conducted his first field research trip in A |
https://en.wikipedia.org/wiki/Eugenio%20Elia%20Levi | Eugenio Elia Levi (18 October 1883 – 28 October 1917) was an Italian mathematician, known for his fundamental contributions in group theory, in the theory of partial differential operators and in the theory of functions of several complex variables. He was a younger brother of Beppo Levi and was killed in action during First World War.
Work
Research activity
He wrote 33 papers, classified by his colleague and friend Mauro Picone according to the scheme reproduced in this section.
Differential geometry
Group theory
He wrote only three papers in group theory: in the first one, discovered what is now called Levi decomposition, which was conjectured by Wilhelm Killing and proved by Élie Cartan in a special case.
Function theory
In the theory of functions of several complex variables he introduced the concept of pseudoconvexity during his investigations on the domain of existence of such functions: it turned out to be one of the key concepts of the theory.
Cauchy and Goursat problems
Boundary value problems
His researches in the theory of partial differential operators lead to the method of the parametrix, which is basically a way to construct fundamental solutions for elliptic partial differential operators with variable coefficients: the parametrix is widely used in the theory of pseudodifferential operators.
Calculus of variations
Publications
The full scientific production of Eugenio Elia Levi is collected in reference .
, reprinted also in , volume I. A a well-known memoir in Group theory: it was presented to the members of the Accademia delle Scienze di Torino during the session of April 2, 1905, by Luigi Bianchi.
. A short note announcing the results of paper .
. An important paper whose results were previously announced in the short note with the same title. It was also translated in Russian by N. D. Ajzenstat, currently available from the All-Russian Mathematical Portal: .
. An important paper in the theory of functions of several complex variables, w |
https://en.wikipedia.org/wiki/Aspera%20European%20Astroparticle%20network | ASPERA (or AStroParticle European Research Area) is a network of national government agencies responsible for coordinating and funding national research efforts in astroparticle physics.
Members
ASPERA comprises the following agencies: FNRS (Belgium), FWO (Belgium), MEYS (Czech Republic), CEA (France), CNRS (France), BMBF (Germany), PTDESY (Germany), DEMOKRITOS (Greece), INFN (Italy), FOM (Netherlands), FCT (Portugal), FECYT (Spain), MEC (Spain), SNF (Switzerland), VR (Sweden), STFC (United Kingdom) and the European organization CERN.
History
ASPERA started in July 2006 and is funded by the European Commission over a three-year period.
ASPERA has come about through the existence of ApPEC (Astroparticle Physics European Coordination/Consortium) which was founded in 2001 when six European scientific agencies took the initiative to coordinate and encourage Astroparticle Physics in Europe.
Roadmap
One of the most important achievements of ASPERA was to produce a common European Roadmap for the future, in the field of astroparticle physics.
Published in September 2008 in Brussels, the Roadmap presents the "Magnificent Seven", which are the Seven large infrastructures expected in the next 10 years to answer some of the most exciting questions about the Universe such as: What is dark matter? What is the origin of cosmic rays? What is the role of violent cosmic processes? Can we detect gravitational waves?
CTA, The Cherenkov Telescope Array, a large array of Cherenkov Telescopes for detection of cosmic high-energy gamma rays
KM3NeT, a cubic kilometre-scale neutrino telescope in the Mediterranean Sea
Ton-scale detectors for dark matter searches, such as EURECA
A ton-scale detector for the determination of the fundamental nature and mass of neutrinos
A Megaton-scale detector for proton decay’s search, neutrino astrophysics & investigation of neutrino properties
A large array for the detection of charged cosmic rays
A third-generation underground gravitational ant |
https://en.wikipedia.org/wiki/Astroparticle%20Physics%20%28journal%29 | Astroparticle Physics is a peer-reviewed scientific journal covering experimental and theoretical research in the interacting fields of cosmic ray physics, astronomy and astrophysics, cosmology, and particle physics. It was established in 1992 and is published monthly by North-Holland, an imprint of Elsevier. According to the Journal Citation Reports, the journal has a 2020 impact factor of 2.724. |
https://en.wikipedia.org/wiki/Line%20discipline | A line discipline (LDISC) is a layer in the terminal subsystem in some Unix-like systems. The terminal subsystem consists of three layers: the upper layer to provide the character device interface, the lower hardware driver to communicate with the hardware or pseudo terminal, and the middle line discipline to implement behavior common to terminal devices.
The line discipline glues the low level device driver code with the high level generic interface routines (such as read(2), write(2) and ioctl(2)), and is responsible for implementing the semantics associated with the device. The policy is separated from the device driver so that the same serial hardware driver can be used by devices that require different data handling.
For example, the standard line discipline processes the data it receives from the hardware driver and from applications writing to the device according to the requirements of a terminal on a Unix-like system. On input, it handles special characters such as the interrupt character (typically Control-C) and the erase and kill characters (typically backspace or delete, and Control-U, respectively) and, on output, it replaces all the LF characters with a CR/LF sequence.
A serial port could also be used for a dial-up Internet connection using a serial modem and PPP. In this case, a PPP line discipline would be used; it would accumulate input data from the serial line into PPP input packets, delivering them to the networking stack rather than to the character device, and would transmit packets delivered to it by the networking stack on the serial line.
Some Unix-like systems use STREAMS to implement line disciplines. |
https://en.wikipedia.org/wiki/Leukocyte%20extravasation | Leukocyte extravasation (also commonly known as leukocyte adhesion cascade or diapedesis – the passage of cells through the intact vessel wall) is the movement of leukocytes out of the circulatory system and towards the site of tissue damage or infection. This process forms part of the innate immune response, involving the recruitment of non-specific leukocytes. Monocytes also use this process in the absence of infection or tissue damage during their development into macrophages.
Overview
Leukocyte extravasation occurs mainly in post-capillary venules, where haemodynamic shear forces are minimised. This process can be understood in several steps:
Chemoattraction
Rolling adhesion
Tight adhesion
(Endothelial) Transmigration
It has been demonstrated that leukocyte recruitment is halted whenever any of these steps is suppressed.
White blood cells (leukocytes) perform most of their functions in tissues. Functions include phagocytosis of foreign particles, production of antibodies, secretion of inflammatory response triggers (histamine and heparin), and neutralization of histamine. In general, leukocytes are involved in the defense of an organism and protect it from disease by promoting or inhibiting inflammatory responses.
Leukocytes use the blood as a transport medium to reach the tissues of the body. Here is a brief summary of each of the four steps currently thought to be involved in leukocyte extravasation:
Chemoattraction
Upon recognition of and activation by pathogens, resident macrophages in the affected tissue release cytokines such as IL-1, TNFα and chemokines. IL-1, TNFα and C5a cause the endothelial cells of blood vessels near the site of infection to express cellular adhesion molecules, including selectins. Circulating leukocytes are localised towards the site of injury or infection due to the presence of chemokines.
Rolling adhesion
Like velcro, carbohydrate ligands on the circulating leukocytes bind to selectin molecules on the inner wall of the |
https://en.wikipedia.org/wiki/Piecewise%20linear%20continuation | Simplicial continuation, or piecewise linear continuation (Allgower and Georg), is a one-parameter continuation method which is well suited to small to medium embedding spaces. The algorithm has been generalized to compute higher-dimensional manifolds by (Allgower and Gnutzman) and (Allgower and Schmidt).
The algorithm for drawing contours is a simplicial continuation algorithm, and since it is easy to visualize, it serves as a good introduction to the algorithm.
Contour plotting
The contour plotting problem is to find the zeros (contours) of ( a smooth scalar valued function) in the square ,
The square is divided into small triangles, usually by introducing points at the corners of a regular square mesh , , making a table of the values of at each corner , and then dividing each square into two triangles. The value of at the corners of the triangle defines a unique Piecewise Linear interpolant to over each triangle. One way of writing this interpolant on the triangle with corners
is as the set of equations
The first four equations can be solved for (this maps the original triangle to a right unit triangle), then the remaining equation gives the interpolated value of . Over the whole mesh of triangles, this piecewise linear interpolant is continuous.
The contour of the interpolant on an individual triangle is a line segment (it is an interval on the intersection of two planes). The equation for the line can be found, however the points where the line crosses the edges of the triangle are the endpoints of the line segment.
The contour of the linear interpolant over a triangle
The contour of the piecewise linear interpolant is a set of curves made up of these line segments. Any point on the edge connecting and can be written as
with in , and the linear interpolant over the edge is
So setting
and
Since this only depends on values on the edge, every triangle which shares this edge will produce the same point, so the contour wil |
https://en.wikipedia.org/wiki/Sum-free%20set | In additive combinatorics and number theory, a subset A of an abelian group G is said to be sum-free if the sumset A + A is disjoint from A. In other words, A is sum-free if the equation has no solution with .
For example, the set of odd numbers is a sum-free subset of the integers, and the set {N + 1, ..., 2N } forms a large sum-free subset of the set {1, ..., 2N }. Fermat's Last Theorem is the statement that, for a given integer n > 2, the set of all nonzero nth powers of the integers is a sum-free set.
Some basic questions that have been asked about sum-free sets are:
How many sum-free subsets of {1, ..., N } are there, for an integer N? Ben Green has shown that the answer is , as predicted by the Cameron–Erdős conjecture.
How many sum-free sets does an abelian group G contain?
What is the size of the largest sum-free set that an abelian group G contains?
A sum-free set is said to be maximal if it is not a proper subset of another sum-free set.
Let be defined by is the largest number such that any subset of with size n has a sum-free subset of size k. The function is subadditive, and by the Fekete subadditivity lemma, exists. Erdős proved that , and conjectured that equality holds. This was proved by Eberhard, Green, and Manners.
See also
Erdős–Szemerédi theorem
Sum-free sequence |
https://en.wikipedia.org/wiki/Weyl%E2%80%93Brauer%20matrices | In mathematics, particularly in the theory of spinors, the Weyl–Brauer matrices are an explicit realization of a Clifford algebra as a matrix algebra of matrices. They generalize the Pauli matrices to dimensions, and are a specific construction of higher-dimensional gamma matrices. They are named for Richard Brauer and Hermann Weyl, and were one of the earliest systematic constructions of spinors from a representation theoretic standpoint.
The matrices are formed by taking tensor products of the Pauli matrices, and the space of spinors in dimensions may then be realized as the column vectors of size on which the Weyl–Brauer matrices act.
Construction
Suppose that V = Rn is a Euclidean space of dimension n. There is a sharp contrast in the construction of the Weyl–Brauer matrices depending on whether the dimension n is even or odd.
Let = 2 (or 2+1) and suppose that the Euclidean quadratic form on is given by
where (pi, qi) are the standard coordinates on Rn.
Define matrices 1, 1', P, and Q by
.
In even or in odd dimensionality, this quantization procedure amounts to replacing the ordinary p, q coordinates with non-commutative coordinates constructed from P, Q in a suitable fashion.
Even case
In the case when n = 2k is even, let
for i = 1,2,...,k (where the P or Q is considered to occupy the i-th position). The operation is the tensor product of matrices. It is no longer important to distinguish between the Ps and Qs, so we shall simply refer to them all with the symbol P, and regard the index on Pi as ranging from i = 1 to i = 2k. For instance, the following properties hold:
, and for all unequal pairs i and j. (Clifford relations.)
Thus the algebra generated by the Pi is the Clifford algebra of euclidean n-space.
Let A denote the algebra generated by these matrices. By counting dimensions, A is a complete 2k×2k matrix algebra over the complex numbers. As a matrix algebra, therefore, it acts on 2k-dimensional column vectors (with complex entr |
https://en.wikipedia.org/wiki/1%3A35%20scale | 1:35 scale is the most popular scale for model military vehicles, with an extensive lineup of models and aftermarket parts available from a wide variety of manufacturers.
The roots of 1:35 as a military modelling scale lie in early motorized plastic tank kits. To accommodate electric motors and gearboxes, these models needed to be made in a larger scale. There were many companies making such tanks, but it was Tamiya's example that made 1:35 a de facto standard.
Company chairman Shunsaku Tamiya explains the origins of the scale in his book Master Modeler:
After the success of the Panther, I thought it would be a good idea for us to produce other tanks from different countries in the same scale. I measured the Panther and it turned out to be about 1/35 of the size of the original. This size had been chosen simply because it would accommodate a couple of B-type batteries. Tamiya's 1/35 series tanks eventually got to be known around the world, but this is the slightly haphazard origin of their rather awkward scale.
Early kits in the scale, built around bulky motorization components, often sacrificed scale appearance and detail, but their large size and potential for intricate superdetailing appealed to hobbyists.
Over the years, kits have become more and more detailed and accurate, and nowadays there is a whole industry in 1:35 dedicated to offering aftermarket detail parts for kits. After a new kit is released, companies like Aber and Eduard usually make detail sets available for it, allowing modellers to replace kit parts with more accurate photoetched alternatives.
In terms of model range, 1:35 is typically limited to military land vehicles and figures. Some helicopter kits also exist in the scale, whereas large airplane kits are more commonly done in 1:32 scale. In recent years, there have been some aeroplane releases in 1:35 as well, typically of vehicles operating in close contact with ground forces, such as the Fieseler Storch liaison aircraft or the Horsa |
https://en.wikipedia.org/wiki/Direct%20methods%20%28crystallography%29 | In crystallography, direct methods are a family of methods for estimating the phases of the Fourier transform of the scattering density from the corresponding magnitudes. The methods generally exploit constraints or statistical correlations between the phases of different Fourier components that result from the fact that the scattering density must be a positive real number.
In two dimensions, it is relatively easy to solve the phase problem directly, but not so in three dimensions. The key step was taken by Hauptman and Karle, who developed a practical method to employ the Sayre equation for which they were awarded the 1985 Nobel prize in Chemistry. The Nobel Prize citation was "for their outstanding achievements in the development of direct methods for the determination of crystal structures."
At present, direct methods are the preferred method for phasing crystals of small molecules having up to 1000 atoms in the asymmetric unit. However, they are generally not feasible by themselves for larger molecules such as proteins.
Several software packages implement direct methods.
See also
Direct methods (electron microscopy)
Phase problem
X-ray crystallography |
https://en.wikipedia.org/wiki/Belt%20problem | The belt problem is a mathematics problem which requires finding the length of a crossed belt that connects two circular pulleys with radius r1 and r2 whose centers are separated by a distance P. The solution of the belt problem requires trigonometry and the concepts of the bitangent line, the vertical angle, and congruent angles.
Solution
Clearly triangles ACO and ADO are congruent right angled triangles, as are triangles BEO and BFO. In addition, triangles ACO and BEO are similar. Therefore angles CAO, DAO, EBO and FBO are all equal. Denoting this angle by (denominated in radians), the length of the belt is
This exploits the convenience of denominating angles in radians that the length of an arc = the radius × the measure of the angle facing the arc.
To find we see from the similarity of triangles ACO and BEO that
For fixed P the length of the belt depends only on the sum of the radius values r1 + r2, and not on their individual values.
Pulley problem
There are other types of problems similar to the belt problem. The pulley problem, as shown, is similar to the belt problem; however, the belt does not cross itself. In the pulley problem the length of the belt is
where r1 represents the radius of the larger pulley, r2 represents the radius of the smaller one, and:
Applications
The belt problem is used in the design of aeroplanes, bicycle gearing, cars, and other items with pulleys or belts that cross each other. The pulley problem is also used in the design of conveyor belts found in airport luggage belts and automated factory lines.
See also
Tangent lines to circles |
https://en.wikipedia.org/wiki/Chow%27s%20lemma | Chow's lemma, named after Wei-Liang Chow, is one of the foundational results in algebraic geometry. It roughly says that a proper morphism is fairly close to being a projective morphism. More precisely, a version of it states the following:
If is a scheme that is proper over a noetherian base , then there exists a projective -scheme and a surjective -morphism that induces an isomorphism for some dense open
Proof
The proof here is a standard one.
Reduction to the case of irreducible
We can first reduce to the case where is irreducible. To start, is noetherian since it is of finite type over a noetherian base. Therefore it has finitely many irreducible components , and we claim that for each there is an irreducible proper -scheme so that has set-theoretic image and is an isomorphism on the open dense subset of . To see this, define to be the scheme-theoretic image of the open immersion
Since is set-theoretically noetherian for each , the map is quasi-compact and we may compute this scheme-theoretic image affine-locally on , immediately proving the two claims. If we can produce for each a projective -scheme as in the statement of the theorem, then we can take to be the disjoint union and to be the composition : this map is projective, and an isomorphism over a dense open set of , while is a projective -scheme since it is a finite union of projective -schemes. Since each is proper over , we've completed the reduction to the case irreducible.
can be covered by finitely many quasi-projective -schemes
Next, we will show that can be covered by a finite number of open subsets so that each is quasi-projective over . To do this, we may by quasi-compactness first cover by finitely many affine opens , and then cover the preimage of each in by finitely many affine opens each with a closed immersion in to since is of finite type and therefore quasi-compact. Composing this map with the open immersions and , we see that each is a closed s |
https://en.wikipedia.org/wiki/Penicillium%20expansum | Penicillium expansum is a psychrophilic blue mold that is common throughout the world in soil. It causes Blue Mold of apples, one of the most prevalent and economically damaging post-harvest diseases of apples.
Though primarily known as a disease of apples, this plant pathogen can infect a wide range of hosts, including pears, strawberries, tomatoes, corn, and rice. Penicillium expansum produces the carcinogenic metabolite patulin, a neurotoxin that is harmful when consumed. Patulin is produced by the fungus as a virulence factor as it infects the host. Patulin levels in foods are regulated by the governments of many developed countries. Patulin is a particular health concern for young children, who are often heavy consumers of apple products. The fungus can also produce the mycotoxin citrinin.
Hosts and disease development
Penicillium expansum has a wide host range, causing similar symptoms on fruits which include apples, pears, cherries, and citrus . Initial infection most often occurs at sites of fruit injury, such as bruises or puncture wounds. Although infections may start in the field, infected spots often become evident post-harvest, and expand while fruit is in storage. Infected areas are clearly delineated and light brown, and soft decaying tissue can be easily "scooped" out of the surrounding healthy tissue., Spore masses later appear on the surfaces of infected fruit, initially appearing as white mycelium, then turning blue to blue-green in color as the asexual spores mature. Fruit affected by P. expansum typically has an earthy, musty odor. Lesions measure 1–1.25 inches in diameter eight to ten weeks after infection if kept under cold storage conditions. Age factors into P. expansum infection, in that overripe or mature fruits are most susceptible to infection, while those picked underripe are less likely to become infected.
In apples, the colors of the lesions may vary with variety, from lighter-brown on green and yellow apple varieties to dark-bro |
https://en.wikipedia.org/wiki/Peronospora%20trifoliorum | Peronospora trifoliorum, commonly known as downy mildew of alfalfa, is an oomycete plant pathogen infecting alfalfa.
Hosts and symptoms
Peronospora trifoliorum commonly infects numerous strains and varieties of alfalfa. On alfalfa, the primary symptoms of Peronospora trifoliorum are chlorotic leaf blotches that range from light green to yellow-green to gray-green; rolled or downturned leaves; and thickened, stunted stems ending in rosette-like growths. The main method of identifying the disease is by the moldy, downy growth on the underside of leaves that appears white, gray, or light purple as this is a diagnostic sign of downy mildew of alfalfa (Davis, Frate, and Putnam, 2017). Only seedlings and young tissue are susceptible to infection which, with proper cultural controls, can limit the development and progression of the disease. There is also the potential for secondary infection, which can occur every five days during ideal conditions (Goldberg, 2000).
Peronospora trifoliorum has been reported from Trifolium repens but it is uncommon.
Environment
Peronospora trifoliorum prefers high humidity and moderate to warm temperatures. Peak spore production and infection occurs around 65°F, though the pathogen is active in temperatures between 40 and 85°F (Goldberg, 2000). This means that Peronospora trifoliorum is primarily seen during cool, wet periods in the summer or warmer, dry periods in the spring and fall, and is usually found in the midwestern and southern United States (UW-Extension, 2006). Since Peronospora trifoliorum is an oomycete, free moisture is needed for the disease to spread as well as to infect tissue (Goldberg, 2000). The disease may overwinter in dead leaf debris, in crown buds, or in seeds (UW-Extension, 2006: Pacific Northwest Extension, 2019).
Management
Growing resistant varieties of alfalfa is the most common form of control used against Peronospora trifoliorum (Samac, Rhodes, and Lamp, 2015). A form of cultural control, resistant varieti |
https://en.wikipedia.org/wiki/Nearly%20neutral%20theory%20of%20molecular%20evolution | The nearly neutral theory of molecular evolution is a modification of the neutral theory of molecular evolution that accounts for the fact that not all mutations are either so deleterious such that they can be ignored, or else neutral. Slightly deleterious mutations are reliably purged only when their selection coefficient are greater than one divided by the effective population size. In larger populations, a higher proportion of mutations exceed this threshold for which genetic drift cannot overpower selection, leading to fewer fixation events and so slower molecular evolution.
The nearly neutral theory was proposed by Tomoko Ohta in 1973. The population-size-dependent threshold for purging mutations has been called the "drift barrier" by Michael Lynch, and used to explain differences in genomic architecture among species.
Origins of the nearly neutral theory
According to the neutral theory of molecular evolution, the rate at which molecular changes accumulate between species should be equal to the rate of neutral mutations and hence relatively constant across species. However, this is a per-generation rate. Since larger organisms have longer generation times, the neutral theory predicts that their rate of molecular evolution should be slower. However, molecular evolutionists found that rates of protein evolution were fairly independent of generation time.
Noting that population size is generally inversely proportional to generation time, Tomoko Ohta proposed that if most amino acid substitutions are slightly deleterious, this would increase the rate of effectively neutral mutation rate in small populations, which could offset the effect of long generation times. However, because noncoding DNA substitutions tend to be more neutral, independent of population size, their rate of evolution is correctly predicted to depend on population size / generation time, unlike the rate of non-synonymous changes.
In this case, the faster rate of neutral evolution in proteins |
https://en.wikipedia.org/wiki/MNOS%20%28operating%20system%29 | MNOS (MobilNaya Operatsionnaya Sistema, МобильНая Операционная Система (МНОС), or Portable Operating System) is a Unix-like operating system developed in the Soviet Union.
Overview
The system is derived from Version 6 Unix and then modified to incorporate features of Berkeley Software Distribution (BSD) Unix. From 1983 until 1986, it enjoyed popularity in the Soviet Union and other Eastern Bloc countries, due to its small size and faster performance than that of other Version 7 Unix (and later BSD Unix-based) alternatives.
Its development began in the IPK Minavtoproma in Moscow in 1981, and continued in cooperation with other institutes, including Kurchatov Institute. MNOS and its alternative, DEMOS version 1.x, were gradually merged from 1986 until 1990 resulting in the joint OS, DEMOS version 2.x. MNOS became the first fully bilingual version of Unix, and uses a proprietary 8-bit Cyrillic script character set, U-code, which was dropped in favor of KOI-8 in the process of merging with DEMOS.
The origin of the version qualifier RL is Rabochaya Loshadka (The working horsy)
See also
DEMOS
MOS (operating system)
Computing in the Soviet Union
Soviet inventions
Unix variants
Discontinued operating systems |
https://en.wikipedia.org/wiki/Whewell%20equation | The Whewell equation of a plane curve is an equation that relates the tangential angle () with arclength (), where the tangential angle is the angle between the tangent to the curve and the -axis, and the arc length is the distance along the curve from a fixed point. These quantities do not depend on the coordinate system used except for the choice of the direction of the -axis, so this is an intrinsic equation of the curve, or, less precisely, the intrinsic equation. If a curve is obtained from another by translation then their Whewell equations will be the same.
When the relation is a function, so that tangential angle is given as a function of arclength, certain properties become easy to manipulate. In particular, the derivative of the tangential angle with respect to arclength is equal to the curvature. Thus, taking the derivative of the Whewell equation yields a Cesàro equation for the same curve.
The concept is named after William Whewell, who introduced it in 1849, in a paper in the Cambridge Philosophical Transactions. In his conception, the angle used is the deviation from the direction of the curve at some fixed starting point, and this convention is sometimes used by other authors as well. This is equivalent to the definition given here by the addition of a constant to the angle or by rotating the curve.
Properties
If the curve is given parametrically in terms of the arc length , then is determined by
which implies
Parametric equations for the curve can be obtained by integrating:
Since the curvature is defined by
the Cesàro equation is easily obtained by differentiating the Whewell equation.
Examples |
https://en.wikipedia.org/wiki/Cascade%20effect%20%28ecology%29 | An ecological cascade effect is a series of secondary extinctions that are triggered by the primary extinction of a key species in an ecosystem. Secondary extinctions are likely to occur when the threatened species are: dependent on a few specific food sources, mutualistic (dependent on the key species in some way), or forced to coexist with an invasive species that is introduced to the ecosystem. Species introductions to a foreign ecosystem can often devastate entire communities, and even entire ecosystems. These exotic species monopolize the ecosystem's resources, and since they have no natural predators to decrease their growth, they are able to increase indefinitely. Olsen et al. showed that exotic species have caused lake and estuary ecosystems to go through cascade effects due to loss of algae, crayfish, mollusks, fish, amphibians, and birds. However, the principal cause of cascade effects is the loss of top predators as the key species. As a result of this loss, a dramatic increase (ecological release) of prey species occurs. The prey is then able to overexploit its own food resources, until the population numbers decrease in abundance, which can lead to extinction. When the prey's food resources disappear, they starve and may go extinct as well. If the prey species is herbivorous, then their initial release and exploitation of the plants may result in a loss of plant biodiversity in the area. If other organisms in the ecosystem also depend upon these plants as food resources, then these species may go extinct as well. An example of the cascade effect caused by the loss of a top predator is apparent in tropical forests. When hunters cause local extinctions of top predators, the predators' prey's population numbers increase, causing an overexploitation of a food resource and a cascade effect of species loss. Recent studies have been performed on approaches to mitigate extinction cascades in food-web networks.
Current example
One example of the cascade ef |
https://en.wikipedia.org/wiki/Mtrace | mtrace is the memory debugger included in the GNU C Library.
Use
Note that mtrace tool works only with single threaded applications. One thread could temporarily remove the hook while another thread could malloc memory at the sametime leading to missed allocations in a multithreaded application!
The function mtrace installs handlers for malloc, realloc and free; the function muntrace disables these handlers. Their prototypes, defined in the header file mcheck.h, are
void mtrace(void);
void muntrace(void);
The handlers log all memory allocations and frees to a file defined by the environment variable MALLOC_TRACE (if the variable is unset, describes an invalid filename, or describes a filename the user does not have permissions to, the handlers are not installed).
A perl script called mtrace, not to be confused with the function of the same name, is also distributed with the GNU C Library; the script parses through the output file and reports all allocations that were not freed.
Usage example
Bad Source Code
The following is an example of bad source code. The problem with the program is that it allocates memory, but doesn't free the memory before exiting.
#include <stdlib.h>
int main(void) {
int * a;
a = malloc(sizeof(int)); /* allocate memory and assign it to the pointer */
return 0; /* we exited the program without freeing memory */
/* we should have released the allocated memory with the statement “free(a)” */
}
MTrace Usage
Set the environment variable MALLOC_TRACE to the pathname of the desired output file. Setting environment variables is slightly different in each shell. In Bourne Shell-compatible shells, like Bash, the command is as follows:
$ MALLOC_TRACE=/home/YourUserName/path/to/program/MallocTraceOutputFile.txt
$ export MALLOC_TRACE
Include mcheck.h in the source code. This is done, for example, by adding the following line to the top of a C or C++ file, as shown below:
#include <mcheck.h>
Call the function mtrace() befor |
https://en.wikipedia.org/wiki/Normative%20social%20influence | Normative social influence is a type of social influence that leads to conformity. It is defined in social psychology as "...the influence of other people that leads us to conform in order to be liked and accepted by them." The power of normative social influence stems from the human identity as a social being, with a need for companionship and association.
Normative social influence involves a change in behaviour that is deemed necessary in order to fit in a particular group. The need for a positive relationship with the people around leads us to conformity. This fact often leads to people exhibiting public compliance—but not necessarily private acceptance—of the group's social norms in order to be accepted by the group. Social norms refers to the unwritten rules that govern social behavior. These are customary standards for behavior that are widely shared by members of a culture.
In many cases, normative social influence serves to promote social cohesion. When a majority of group members conform to social norms, the group generally becomes more stable. This stability translates into social cohesion, which allows group members to work together toward a common understanding, or "good," but also has the unintended impact of making the group members less individualistic.
Research
Classic research
In 1955, Solomon Asch conducted his classic conformity experiments in an attempt to discover if people still conform when the right answer is obvious. Specifically, he asked participants in his experiment to judge the similarity of lines, an easy task by objective standards. Using accomplices to the plot, also known as confederates, Asch created the illusion that an entire group of participants believed something that was clearly false (i.e., that dissimilar lines were actually similar). In this situation, participants conformed over 36% of the time on trials where the confederates gave blatantly false answers. When asked to make the judgments in private, participants g |
https://en.wikipedia.org/wiki/Polarization%20spectroscopy | Polarization spectroscopy comprises a set of spectroscopic techniques based on polarization properties of light (not necessarily visible one; UV, X-ray, infrared, or in any other frequency range of the electromagnetic radiation). By analyzing the polarization properties of light, decisions can be made about the media that emitted the light (or the media the light passes/scatters through). Alternatively, a source of polarized light may be used to probe a media; in this case, the changes in the light polarization (compared to the incidental light) allow inferences about the media's properties.
In general, any kind of anisotropy in the media results in some sort of change in polarization. Such an anisotropy can be either inherent to the media (e.g., in the case of a crystal substance), or imposed externally (e.g., in the presence of magnetic field in plasma or by another laser beam).
See also
Faraday effect
Plasma diagnostics
Stark effect
Zeeman effect |
https://en.wikipedia.org/wiki/Ng%C3%B4%20B%E1%BA%A3o%20Ch%C3%A2u | Ngô Bảo Châu (, born June 28, 1972) is a Vietnamese-French mathematician at the University of Chicago, best known for proving the fundamental lemma for automorphic forms (proposed by Robert Langlands and Diana Shelstad). He is the first Vietnamese national to have received the Fields Medal.
Early life
Ngô Bảo Châu was born in 1972, the son of an intellectual family in Hanoi, North Vietnam. His father, professor Ngô Huy Cẩn, is full professor of physics at the Vietnam National Institute of Mechanics. His mother, Trần Lưu Vân Hiền, is a physician and associate professor at an herbal medicine hospital in Hanoi.
The beginning of Châu's schooling was at an experimental elementary school that had been founded by the revolutionary pedagogue Hồ Ngọc Đại, but when his father returned from the Soviet Union with his doctoral degree, he decided that Châu would learn more in traditional schools and enrolled him in the "chuyên toán" (special classes for gifted students in mathematics) at the Trưng Vương Middle School.
At age 15, Châu entered the special mathematics class at the High School for Gifted Students, Hanoi University of Science (Khối chuyên Tổng Hợp – Đại học Khoa Học Tự Nhiên Hà Nội), formerly known as the A0-class. In grades 11 and 12, Châu participated in the 29th and 30th International Mathematical Olympiads (IMO) and became the first Vietnamese student to win two IMO gold medals, of which the first one was won with a perfect score (42/42).
After high school, Châu expected to study in Budapest, but in the aftermath of the fall of Communism in Eastern Europe, the new Hungarian government halted scholarships to students from Vietnam. After visiting Châu's father, Paul Germain, secretary of the French Academy of Sciences, arranged for Châu to study in France. He was offered a scholarship by the French government for undergraduate study at the Paris VI University, then in 1992, he entered the École Normale Supérieure. He obtained a PhD in 1997 from the Universite Par |
https://en.wikipedia.org/wiki/LOCOS | LOCOS, short for LOCal Oxidation of Silicon, is a microfabrication process where silicon dioxide is formed in selected areas on a silicon wafer having the Si-SiO2 interface at a lower point than the rest of the silicon surface. As of 2008 it was largely superseded by shallow trench isolation.
This technology was developed to insulate MOS transistors from each other and limit transistor cross-talk. The main goal is to create a silicon oxide insulating structure that penetrates under the surface of the wafer, so that the Si-SiO2 interface occurs at a lower point than the rest of the silicon surface. This cannot be easily achieved by etching field oxide. Thermal oxidation of selected regions surrounding transistors is used instead. The oxygen penetrates in depth of the wafer, reacts with silicon and transforms it into silicon oxide. In this way, an immersed structure is formed. For process design and analysis purposes, the oxidation of silicon surfaces can be modeled effectively using the Deal–Grove model. |
https://en.wikipedia.org/wiki/Financial%20result | The financial result is the difference between earnings before interest and taxes and earnings before taxes. It is determined by the earning or the loss which results from financial affairs.
Interpretation
For most industrial companies the financial result is negative, as the interest charged on borrowing generally exceeds income from investments (dividends). If a company records a positive financial Result over several periods, then one has to ask how much capital is invested at which interest rate, and if this capital would not bear a greater yield if it were invested in the company's growth. In case of constant, positive financial results a company also has to deal with increasing demands for special distributions to its shareholders.
Calculation formula
In mathematical terms financial result is defined as follows:
Advantages
The advantages of the use of financial result as a key performance indicator
The financial result provides information about financing costs.
Information may be gained about non-consolidated companies.
Disadvantages
The disadvantages of the use of financial result as a Key performance indicator
Operating components may be included in the financial result (e.g.: the income from financing activities).
Investment income as a component of the financial result does not provide any information on the risk inherent in this investment.
The financial result may vary strongly over time. |
https://en.wikipedia.org/wiki/Direct%20Media%20Interface | In computing, Direct Media Interface (DMI) is Intel's proprietary link between the northbridge (or CPU) and southbridge (e.g. Platform Controller Hub family) chipset on a computer motherboard. It was first used between the 9xx chipsets and the ICH6, released in 2004. Previous Intel chipsets had used the Intel Hub Architecture to perform the same function, and server chipsets use a similar interface called Enterprise Southbridge Interface (ESI). While the "DMI" name dates back to ICH6, Intel mandates specific combinations of compatible devices, so the presence of a DMI interface does not guarantee by itself that a particular northbridge–southbridge combination is allowed.
DMI shares many characteristics with PCI Express, using multiple lanes and differential signaling to form a point-to-point link. Most implementations use a ×4 link, while some mobile systems (e.g. 915GMS, 945GMS/GSE/GU and the Atom N450) use a ×2 link, halving the bandwidth. The original implementation provides 10 Gbit/s (1 GB/s) in each direction using a ×4 link. The DMI provides support for concurrent traffic and isochronous data transfer capabilities.
Versions
DMI 1.0, introduced in 2004.
DMI 2.0, introduced in 2011, doubles the data transfer rate to 2 GB/s with a ×4 link. It is used to link an Intel CPU with the Intel Platform Controller Hub (PCH), which supersedes the historic implementation of a separate northbridge and southbridge.
DMI 3.0, released in August 2015, allows the 8 GT/s transfer rate per lane, for a total of four lanes and 3.93 GB/s for the CPU–PCH link. It is used by two-chip variants of the Intel Skylake microprocessors, which are used in conjunction with Intel 100 Series chipsets; some low power (Skylake-U onwards) and ultra low power (Skylake-Y onwards) mobile Intel processors have the PCH integrated into the physical package as a separate die, referred to as OPI (On Package DMI interconnect Interface) and effectively following the system on a chip (SoC) design layou |
https://en.wikipedia.org/wiki/CSPD%20%28molecule%29 | CSPD ([3-(1-chloro-3'-methoxyspiro[adamantane-4,4'-dioxetane]-3'-yl)phenyl] dihydrogen phosphate) is a chemical substance with formula C18H22ClO7P. It is a component of enhanced chemiluminescence enzyme-linked immunosorbent assay (ELISA) kits, used for the detection of minute amounts of various substances such as proteins.
Properties
The molecule CSPD has the following functional groups in the structure: phosphate group, phenyl group, spiro group, methyl ether group, and chlorine group. The ones worth noting are the ones above. None of these groups carry a charge. If there was a charge this would have had a change in the compound's pH, 3D structure, mass and bond angles.
The toxin CSPD effect persister cell formation using MqsR (MqsR, a crucial regulator for quorum sensing and biofilm formation, is a GCU-specific mRNA interferase in Escherichia coli) and persister cells are cells that avoid stress and are characterized by reduced metabolism and other factors. |
https://en.wikipedia.org/wiki/Biochemical%20systems%20theory | Biochemical systems theory is a mathematical modelling framework for biochemical systems, based on ordinary differential equations (ODE), in which biochemical processes are represented using power-law expansions in the variables of the system.
This framework, which became known as Biochemical Systems Theory, has been developed since the 1960s by Michael Savageau, Eberhard Voit and others for the systems analysis of biochemical processes. According to Cornish-Bowden (2007) they "regarded this as a general theory of metabolic control, which includes both metabolic control analysis and flux-oriented theory as special cases".
Representation
The dynamics of a species is represented by a differential equation with the structure:
where Xi represents one of the nd variables of the model (metabolite concentrations, protein concentrations or levels of gene expression). j represents the nf biochemical processes affecting the dynamics of the species. On the other hand, ij (stoichiometric coefficient), j (rate constants) and fjk (kinetic orders) are two different kinds of parameters defining the dynamics of the system.
The principal difference of power-law models with respect to other ODE models used in biochemical systems is that the kinetic orders can be non-integer numbers. A kinetic order can have even negative value when inhibition is modeled. In this way, power-law models have a higher flexibility to reproduce the non-linearity of biochemical systems.
Models using power-law expansions have been used during the last 35 years to model and analyze several kinds of biochemical systems including metabolic networks, genetic networks and recently in cell signalling.
See also
Dynamical systems
Ludwig von Bertalanffy
Systems theory |
https://en.wikipedia.org/wiki/Mason%27s%20invariant | In electronics, Mason's invariant, named after Samuel Jefferson Mason, is a measure of the quality of transistors.
"When trying to solve a seemingly difficult problem, Sam said to concentrate on the easier ones first; the rest, including the hardest ones, will follow," recalled Andrew Viterbi, co-founder and former vice-president of Qualcomm. He had been a thesis advisee under Samuel Mason at MIT, and this was one lesson he especially remembered from his professor. A few years earlier, Mason had heeded his own advice when he defined a unilateral power gain for a linear two-port device, or U. After concentrating on easier problems with power gain in feedback amplifiers, a figure of merit for all three-terminal devices followed that is still used today as Mason's Invariant.
Origin
In 1953, transistors were only five years old, and they were the only successful solid-state three-terminal active device. They were beginning to be used for RF applications, and they were limited to VHF frequencies and below. Mason wanted to find a figure of merit to compare transistors, and this led him to discover that the unilateral power gain of a linear two-port device was an invariant figure of merit.
In his paper Power Gain in Feedback Amplifiers published in 1953, Mason stated in his introduction, "A vacuum tube, very often represented as a simple transconductance driving a passive impedance, may lead to relatively simple amplifier designs in which the input impedance (and hence the power gain) is effectively infinite, the voltage gain is the quantity of interest, and the input circuit is isolated from the load. The transistor, however, usually cannot be characterized so easily." He wanted to find a metric to characterize and measure the quality of transistors since up until then, no such measure existed. His discovery turned out to have applications beyond transistors.
Derivation of U
Mason first defined the device being studied with the three constraints listed below.
T |
https://en.wikipedia.org/wiki/GF%282%29 | (also denoted , or ) is the finite field of two elements (GF is the initialism of Galois field, another name for finite fields). Notations and may be encountered although they can be confused with the notation of -adic integers.
is the field with the smallest possible number of elements, and is unique if the additive identity and the multiplicative identity are denoted respectively and , as usual.
The elements of may be identified with the two possible values of a bit and to the boolean values true and false. It follows that is fundamental and ubiquitous in computer science and its logical foundations.
Definition
GF(2) is the unique field with two elements with its additive and multiplicative identities respectively denoted and .
Its addition is defined as the usual addition of integers but modulo 2 and corresponds to the table below:
If the elements of GF(2) are seen as boolean values, then the addition is the same as that of the logical XOR operation.
Since each element equals its opposite, subtraction is thus the same operation as addition.
The multiplication of GF(2) is again the usual multiplication modulo 2 (see the table below), and on boolean variables corresponds to the logical AND operation.
GF(2) can be identified with the field of the integers modulo , that is, the quotient ring of the ring of integers Z by the ideal 2Z of all even numbers: .
Properties
Because GF(2) is a field, many of the familiar properties of number systems such as the rational numbers and real numbers are retained:
addition has an identity element (0) and an inverse for every element;
multiplication has an identity element (1) and an inverse for every element but 0;
addition and multiplication are commutative and associative;
multiplication is distributive over addition.
Properties that are not familiar from the real numbers include:
every element x of GF(2) satisfies and therefore ; this means that the characteristic of GF(2) is 2;
every element x of GF( |
https://en.wikipedia.org/wiki/Mebetoys | Meccanica Bessana Toys (mostly known for its acronym and tradename Mebetoys), was an Italian toy manufacturer that produced die-cast scale model cars during the 1960s and 1970s.
The company was purchased by Mattel in 1969, which continued commercialising Mebetoy as one of its brands. Mebetoy's main competition in Italy was the earlier trailblazer Mercury, Polistil and the rarer Ediltoys.
History
Mebetoys was started by Ugo and Martino Besana in 1959 in Oleggio Castello, Italy. Their brother Mario Besana joined the company in 1967, one year after the company started. A diecast car line was started that same year, rather late compared to the entry of many other companies in the early-to-mid-1950s. In detail and proportion, Mebetoys joined superior model producers of French Solido and fellow Italian Polistil, in many ways these became the triumvirate of diecast models on the European continent, though Danish Tekno and Italian Rio Models also were important. Models were exact to scale with many moving parts, and generally more sophisticated than venerable British producers Corgi and Dinky Toys.
Model details
Mebetoys models were known for well-done castings. Some were very clever model selections such as the Autobianchi A66 Elaf petroleum with a roof luggage rack carrying two large plastic oil barrels, or the Porsche 912 Rally (a 911 in rally form) with rock guards in thin yellow plastic strips covering the front windshield and hood and also featuring red and chrome body and bumper supports which extended from front to rear bumper. This car, in 1:43 scale, was topped off, literally, with three spare tires on the roof. Mebetoys Innocenti Mini (Italian-made mini) appeared in several different guises – including with skis and sled on its roof rack. Other models were unique because they were not offered elsewhere, like the ISO Fidia S4 grand touring sedan. Politoys had the Rivolta and Corgi and Matchbox made the Grifo ubiquitous, but nobody else made the Fidia S4. Mod |
https://en.wikipedia.org/wiki/Frictionless%20plane | The frictionless plane is a concept from the writings of Galileo Galilei. In his 1638 The Two New Sciences, Galileo presented a formula that predicted the motion of an object moving down an inclined plane. His formula was based upon his past experimentation with free-falling bodies. However, his model was not based upon experimentation with objects moving down an inclined plane, but from his conceptual modeling of the forces acting upon the object. Galileo understood the mechanics of the inclined plane as the combination of horizontal and vertical vectors; the result of gravity acting upon the object, diverted by the slope of the plane.
However, Galileo's equations do not contemplate friction, and therefore do not perfectly predict the results of an actual experiment. This is because some energy is always lost when one mass applies a non-zero normal force to another. Therefore, the observed speed, acceleration and distance traveled should be less than Galileo predicts. This energy is lost in forms like sound and heat. However, from Galileo's predictions of an object moving down an inclined plane in a frictionless environment, he created the theoretical foundation for extremely fruitful real-world experimental prediction.
Frictionless planes do not exist in the real world. However, if they did, one can be almost certain that objects on them would behave exactly as Galileo predicts. Despite their nonexistence, they have considerable value in the design of engines, motors, roadways, and even tow-truck beds, to name a few examples.
The effect of friction on an object moving down an inclined plane can be calculated as
where is the force of friction exerted by the object and the inclined plane on each other, parallel to the surface of the plane, is the normal force exerted by the object and the plane on each other, directed perpendicular to the plane, and is the coefficient of kinetic friction.
Unless the inclined plane is in a vacuum, a (usually) small amount of |
https://en.wikipedia.org/wiki/Honeywell%20316 | The Honeywell 316 was a popular 16-bit minicomputer built by Honeywell starting in 1969. It is part of the Series 16, which includes the Models 116 (1965, discrete), 316 (1969), 416 (1966), 516 (1966) and DDP-716 (1969). They were commonly used for data acquisition and control, remote message concentration, clinical laboratory systems, Remote Job Entry and time-sharing. The Series-16 computers are all based on the DDP-116 designed by Gardner Hendrie at Computer Control Company, Inc. (3C) in 1964.
The 516 and later the 316 were used as Interface Message Processors (IMP) for the American ARPANET and the British NPL Network.
History
Computer Control Company developed a computer series named Digital Data Processor, of which it built two models:
DDP-116 - the first of the Series 16
DDP-124 - part of a trio of 24-bit systems: DDP-24, 124, 224.
Honeywell bought the company after the 24 trio, and built the balance of the Series 16.
The H-316 was used by Charles H. Moore to develop the first complete, stand-alone implementation of Forth at NRAO. The Honeywell 516 was used in the NPL network, and the 516 and later the 316 were used as Interface Message Processors (IMP) for the ARPANET. It could also be configured as a Terminal IMP (TIP), which added support for up to 63 teletype machines through a multi-line controller.
The original Prime computers were designed to be compatible with the Series-16 minicomputers.
The Honeywell 316 also had industrial applications. A 316 was used at Bradwell nuclear power station in Essex as the primary reactor temperature-monitoring computer until summer 2000, when the internal 160k disk failed. Two PDP-11/70s, which had previously been secondary monitors, were moved to primary.
Hardware description
The 316 succeeded the earlier DDP-516 model and was promoted by Honeywell as suitable for industrial process control, data-acquisition systems, and as a communications concentrator and processor. The computer processor was made from small- |
https://en.wikipedia.org/wiki/Tetrad%20formalism | The tetrad formalism is an approach to general relativity that generalizes the choice of basis for the tangent bundle from a coordinate basis to the less restrictive choice of a local basis, i.e. a locally defined set of four linearly independent vector fields called a tetrad or vierbein. It is a special case of the more general idea of a vielbein formalism, which is set in (pseudo-)Riemannian geometry. This article as currently written makes frequent mention of general relativity; however, almost everything it says is equally applicable to (pseudo-)Riemannian manifolds in general, and even to spin manifolds. Most statements hold simply by substituting arbitrary for . In German, "" translates to "four", and "" to "many".
The general idea is to write the metric tensor as the product of two vielbeins, one on the left, and one on the right. The effect of the vielbeins is to change the coordinate system used on the tangent manifold to one that is simpler or more suitable for calculations. It is frequently the case that the vielbein coordinate system is orthonormal, as that is generally the easiest to use. Most tensors become simple or even trivial in this coordinate system; thus the complexity of most expressions is revealed to be an artifact of the choice of coordinates, rather than a innate property or physical effect. That is, as a formalism, it does not alter predictions; it is rather a calculational technique.
The advantage of the tetrad formalism over the standard coordinate-based approach to general relativity lies in the ability to choose the tetrad basis to reflect important physical aspects of the spacetime. The abstract index notation denotes tensors as if they were represented by their coefficients with respect to a fixed local tetrad. Compared to a completely coordinate free notation, which is often conceptually clearer, it allows an easy and computationally explicit way to denote contractions.
The significance of the tetradic formalism appear in the E |
https://en.wikipedia.org/wiki/OnStream | OnStream Holdings of the Netherlands was spun off from Philips in 1998 and went bankrupt for a second time in 2003.
As a result of its first bankruptcy in 2001, the company was split into two parts, OnStream Data and OnStream MST. The "Data" division manufactured magnetic tape products and the "MST" division produced the thin film tape heads. MST also produced microsieves and microelectromechanical systems products. After the second OnStream bankruptcy in 2003, the MST division was reborn as fluXXion, a maker of high-tech filtering products. fluXXion had some success in filtering beer and other food products but went bankrupt in 2011.
Prior to the first bankruptcy, the CEO was William B. Beierwaltes, a tape systems pioneer and founder of Colorado Memory Systems.
The company's magnetic tape data storage technology was called Advanced Digital Recording (ADR). Tape drives based on this technology were relatively high in data capacity and low in price. |
https://en.wikipedia.org/wiki/Peter%20L.%20Hagelstein | Peter L. Hagelstein is an associate professor of electrical engineering at the Massachusetts Institute of Technology (MIT), affiliated with the Research Laboratory of Electronics (RLE).
Hagelstein received a B.S. and M.S. in 1976 and Ph.D. in electrical engineering in 1981, from MIT.
Hagelstein began his career at the Lawrence Livermore National Laboratory, working on high-energy laser and plasma physics from 1981 to 1985. While working in the Lawrence Livermore National Laboratory, he pioneered the work that later produced the first X-ray laser, which would later become important for the US Strategic Defense Initiative, popularly referred to as the "Star Wars" program. His work on X-ray lasers was honored with the Ernest Orlando Lawrence Award in 1984. Following this time, he took up an academic appointment at MIT in 1986.
In 1989, he started investigating cold fusion (also called low-energy nuclear reactions) with the hope of making a breakthrough similar to the X-ray laser. In the period between 1989 and 2004, the field became discredited in the eyes of many scientists. Hagelstein continued his research activity in the field, chairing the Tenth International Conference on Cold Fusion in 2003. On November 14th, 2017, he gave a 90 minute presentation reviewing relevant experiments and describing possible mechanisms.
Following the cold fusion episode, his primary research has shifted to solid-state physics, including the development of new thermoelectric materials. In addition, he is active in education, writing a textbook on quantum and statistical mechanics. |
https://en.wikipedia.org/wiki/Encyclopedia%20of%20Life | The Encyclopedia of Life (EOL) is a free, online encyclopedia intended to document all of the 1.9 million living species known to science. It is compiled from existing trusted databases curated by experts and with the assistance of non-experts throughout the world. It aims to build one "infinitely expandable" page for each species, including video, sound, images, graphics, as well as text. In addition, the Encyclopedia incorporates content from the Biodiversity Heritage Library, which digitizes millions of pages of printed literature from the world's major natural history libraries. The project was initially backed by a US$50 million funding commitment, led by the MacArthur Foundation and the Sloan Foundation, who provided US$20 million and US$5 million, respectively. The additional US$25 million came from five cornerstone institutions—the Field Museum, Harvard University, the Marine Biological Laboratory, the Missouri Botanical Garden, and the Smithsonian Institution. The project was initially led by Jim Edwards and the development team by David Patterson. Today, participating institutions and individual donors continue to support EOL through financial contributions.
Overview
EOL went live on 26 February 2008 with 30,000 entries. The site immediately proved to be extremely popular, and temporarily had to revert to demonstration pages for two days when over 11 million views of it were requested.
The site relaunched on 5 September 2011 with a redesigned interface and tools. The new version – referred to as EOLv2 – was developed in response to requests from the general public, citizen scientists, educators and professional biologists for a site that was more engaging, accessible and personal. EOLv2 is redesigned to enhance usability and encourage contributions and interactions among users. It is also internationalized with interfaces provided for English, German, Spanish, French, Galician, Serbian, Macedonian, Arabic, Chinese, Korean and Ukrainian language speakers |
https://en.wikipedia.org/wiki/Tower%20Mounted%20Amplifier | A Tower Mounted Amplifier (TMA), or Mast Head Amplifier (MHA), is a low-noise amplifier (LNA) mounted as close as practical to the antenna in mobile masts or base transceiver stations. A TMA reduces the base transceiver station noise figure (NF) and therefore improves its overall sensitivity; in other words the mobile mast is able to receive weaker signals.
The power to feed the amplifier (in the top of the mast) is usually a DC component on the same coaxial cable that feeds the antenna, otherwise an extra power cable has to be run to the TMA/MHA to supply it with power.
Benefits in mobile communications
In two way communications systems, there are occasions when one way, one link, is weaker than the other, normally referenced as unbalanced links. This can be fixed by making the transmitter on that link stronger or the receiver more sensitive to weaker signals.
TMAs are used in mobile networks to improve the sensitivity of the uplink in mobile phone masts. Since the transmitter in a mobile phone it cannot be easily modified to transmit stronger signals. Improving the uplink translates into a combination of better coverage and mobile transmitting at less power, which in turn implies a lower drain from its batteries, thus a longer battery charge.
There are occasions when the cable between the antenna and the receiver is so lossy (too thin or too long) that the signal weakens from the antenna before reaching the receiver; therefore it may be decided to install TMAs from the start to make the system viable. In other words, the TMA can only partially correct, or palliate, the link imbalance.
Drawbacks/pitfalls
If the received signal is not weak, installing a TMA will not deliver its intended benefit.
If the received signal is strong enough, it may cause the TMA to create its own interference which is passed on to the receiver.
In some mobile networks (e.g. IS-95 or WCDMA - aka European 3G -), it is not simple to detect and correct unbalanced links since the li |
https://en.wikipedia.org/wiki/Uzel%20%28computer%29 | Uzel was the Soviet Union's first digital computer used on submarines, to assist in tracking multiple targets and calculate torpedo solutions. Uzel's design team was headed by two American defectors to the Soviet Union, Alfred Sarant (a.k.a. Philip Staros) and Joel Barr (a.k.a. Joseph Berg). An upgraded version of the Uzel computer is still in use on the Kilo class submarine today. |
https://en.wikipedia.org/wiki/Light-gated%20ion%20channel | Light-gated ion channels are a family of ion channels regulated by electromagnetic radiation. Other gating mechanisms for ion channels include voltage-gated ion channels, ligand-gated ion channels, mechanosensitive ion channels, and temperature-gated ion channels. Most light-gated ion channels have been synthesized in the laboratory for study, although two naturally occurring examples, channelrhodopsin and anion-conducting channelrhodopsin, are currently known. Photoreceptor proteins, which act in a similar manner to light-gated ion channels, are generally classified instead as G protein-coupled receptors.
Mechanism
Light-gated ion channels function in a similar manner to other gated ion channels. Such transmembrane proteins form pores through lipid bilayers to facilitate the passage of ions. These ions move from one side of the membrane to another under the influence of an electrochemical gradient. When exposed to a stimulus, a conformational change occurs in the transmembrane region of the protein to open or close the ion channel. In the specific case of light-gated ion channels, the transmembrane proteins are usually coupled with a smaller molecule that acts as a photoswitch, whereby photons bind to the switching molecule, to then alter the conformation of the proteins, so that the pore changes from a closed state to an open state, or vice versa, thereby increasing or decreasing ion conductance. Retinal is a good example of a molecular photoswitch and is found in the naturally occurring channelrhodopsins.
Synthetic isoforms
Once channelrhosopsin had been identified and characterized, the channel's ion selectivity was modified in order to control membrane potential through optogenetic control. Directed mutations of the channel changed the charges lining the pore, resulting in a pore which instead excluded cations in favor of anions.
Other types of gated ion channels, ligand-gated and voltage-gated, have been synthesized with a light-gated component in an atte |
https://en.wikipedia.org/wiki/Toxic%20cough%20syrup | Since the 1990s, several mass poisonings from toxic cough syrup have occurred in developing countries. In these cases, an ingredient in cough syrup, glycerine (glycerol), was replaced with diethylene glycol, a cheaper alternative to glycerine for industrial applications. Diethylene glycol is nephrotoxic and can result in multiple organ dysfunction syndrome (MODS), especially in children.
History
There have been poisonings in Panama, China, Haiti, Bangladesh, Argentina, Nigeria, India (twice), Pakistan, Indonesia, Uzbekistan and The Gambia between 1992 and 2022, due to contaminated cough syrup and other medications that incorporated inexpensive diethylene glycol instead of glycerine.
Bangladesh
Discovering and tracing a toxic syrup to its source has been difficult for health care providers and governmental agencies due to difficult communication between the governments of developed countries and developing countries. For example, Michael L. Bennish, an American pediatrician who works in developing countries, had been volunteering in Bangladesh as a physician and had noticed a number of deaths that seemed to coincide with the distribution of the government-issued cough syrup. The government rebuffed his attempts at investigating the medication. In response, Bennish smuggled bottles of the syrup in his suitcase when returning to the United States, allowing pharmaceutical laboratories in Massachusetts to identify the poisonous diethylene glycol, which can appear very similar to the less dangerous glycerine. Bennish went on to author a 1995 article in the British Medical Journal about his experience, writing that, given the amount of medication prescribed, death tolls "must [already] be in the tens of thousands".
Indonesia
In 2022, deaths of nearly 100 children in Indonesia, were reported to be linked to cough syrup and liquid medication. The syrup contained "unacceptable amounts" of diethylene glycol and ethylene glycol, linked to acute kidney injuries (AKI). In Oct |
https://en.wikipedia.org/wiki/Subcarrier%20multiplexing | Subcarrier Multiplexing (SCM) is a method for combining (multiplexing) many different communications signals so that they can be transmitted along a single optical fiber. SCM (also known as SCMA, SubCarrier Multiple Access) is used in passive optical network (PON) access infrastructures as a variant of wavelength division multiplexing (WDM).
SCM follows a different approach compared to WDM. In WDM an optical carrier is modulated with a baseband signal of typically hundred of Mbit/s. In an SCMA infrastructure, the baseband data is first modulated on a GHz wide subcarrier, that is subsequently modulated on the optical carrier. This way each signal occupies a different portion of the optical spectrum surrounding the centre frequency of the optical carrier. At the receiving side, as normally happens in a commercial radio service, the receiver is tuned to the correct subcarrier frequency, filtering out the other subcarriers.
The operation of multiplexing and demultiplexing the single subcarriers is carried out electronically. The conversion into the optical carrier is done at the multiplexer side. This gives an advantage over a pure WDM access, due to the lower cost of the electrical components if compared with an optical multiplexer.
SCM has the disadvantage of being limited in maximum subcarrier frequencies and data rates by the available bandwidth of the electrical and optical components. Therefore, SCM must be used in conjunction with WDM in order to take advantage of most of the available fiber bandwidth, but it can be used effectively for lower-speed, lower-cost multiuser systems. |
https://en.wikipedia.org/wiki/Photodisintegration | Photodisintegration (also called phototransmutation, or a photonuclear reaction) is a nuclear process in which an atomic nucleus absorbs a high-energy gamma ray, enters an excited state, and immediately decays by emitting a subatomic particle. The incoming gamma ray effectively knocks one or more neutrons, protons, or an alpha particle out of the nucleus. The reactions are called (γ,n), (γ,p), and (γ,α).
Photodisintegration is endothermic (energy absorbing) for atomic nuclei lighter than iron and sometimes exothermic (energy releasing) for atomic nuclei heavier than iron. Photodisintegration is responsible for the nucleosynthesis of at least some heavy, proton-rich elements via the p-process in supernovae of type Ib, Ic, or II.
This causes the iron to further fuse into the heavier elements.
Photodisintegration of deuterium
A photon carrying 2.22 MeV or more energy can photodisintegrate an atom of deuterium:
{| border="0"
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| ||+ || ||→ || ||+ ||
|}
James Chadwick and Maurice Goldhaber used this reaction to measure the proton-neutron mass difference. This experiment proves that a neutron is not a bound state of a proton and an electron, as had been proposed by Ernest Rutherford.
Photodisintegration of beryllium
A photon carrying 1.67 MeV or more energy can photodisintegrate an atom of beryllium-9 (100% of natural beryllium, its only stable isotope):
{| border="0"
|- style="height:2em;"
| ||+ || ||→ ||2|| ||+ ||
|}
Antimony-124 is assembled with beryllium to make laboratory neutron sources and startup neutron sources. Antimony-124 (half-life 60.20 days) emits β− and 1.690MeV gamma rays (also 0.602MeV and 9 fainter emissions from 0.645 to 2.090 MeV), yielding stable tellurium-124. Gamma rays from antimony-124 split beryllium-9 into two alpha particles and a neutron with an average kinetic energy of 24keV, intermediate neutrons. The other products are two alpha particles.
{| border="0"
|- style="height:2em;"
| ||→ ||||+ || ||+ ||
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Other iso |
https://en.wikipedia.org/wiki/Acousto-optic%20deflector | An acousto-optic deflector (AOD) is a device that uses the interaction between sound waves and light waves to deflect or redirect a laser beam. AODs are essentially the same as acousto-optic modulators (AOMs). In both an AOM and an AOD, the amplitude and frequency of different orders are adjusted as light is diffracted.
Operation
In the operation of an acousto-optic deflector the power driving the acoustic transducer is kept on, at a constant level, while the acoustic frequency is varied to deflect the beam to different angular positions. The acousto-optic deflector makes use of the acoustic frequency dependent diffraction angle, where a change in the angle as a function of the change in frequency given as,
where is the optical wavelength and is the velocity of the acoustic wave.
Impact
AOM technology has made Bose–Einstein condensation practical, for which the 2001 Nobel Prize in Physics was awarded to Eric A. Cornell, Wolfgang Ketterle and Carl E. Wieman. Another application of acoustic-optical deflection is optical trapping of small molecules.
See also
Acousto-optic modulator
Acousto-optics
Acousto-optical spectrometer
Nonlinear optics
Sonoluminescence |
https://en.wikipedia.org/wiki/Kempner%20function | In number theory, the Kempner function is defined for a given positive integer to be the smallest number such that divides the For example, the number does not divide , , but does
This function has the property that it has a highly inconsistent growth rate: it grows linearly on the prime numbers but only grows sublogarithmically at the factorial numbers.
History
This function was first considered by François Édouard Anatole Lucas in 1883, followed by Joseph Jean Baptiste Neuberg in 1887. In 1918, A. J. Kempner gave the first correct algorithm for
The Kempner function is also sometimes called the Smarandache function following Florentin Smarandache's rediscovery of the function
Properties
Since is always at A number greater than 4 is a prime number if and only That is, the numbers for which is as large as possible relative to are the primes. In the other direction, the numbers for which is as small as possible are the factorials: for
is the smallest possible degree of a monic polynomial with integer coefficients, whose values over the integers are all divisible
For instance, the fact that means that there is a cubic polynomial whose values are all zero modulo 6, for instance the polynomial
but that all quadratic or linear polynomials (with leading coefficient one) are nonzero modulo 6 at some integers.
In one of the advanced problems in The American Mathematical Monthly, set in 1991 and solved in 1994, Paul Erdős pointed out that the function coincides with the largest prime factor of for "almost all" (in the sense that the asymptotic density of the set of exceptions is zero).
Computational complexity
The Kempner function of an arbitrary number is the maximum, over the prime powers dividing , of .
When is itself a prime power , its Kempner function may be found in polynomial time by sequentially scanning the multiples of until finding the first one whose factorial contains enough multiples The same algorithm can be extended t |
https://en.wikipedia.org/wiki/Guild%20%28ecology%29 | A guild (or ecological guild) is any group of species that exploit the same resources, or that exploit different resources in related ways. It is not necessary that the species within a guild occupy the same, or even similar, ecological niches.
Details
Guilds are defined according to the locations, attributes, or activities of their component species. For example, the mode of acquiring nutrients, the mobility, and the habitat zones that the species occupy or exploit can be used to define a guild. The number of guilds occupying an ecosystem is termed its disparity. Members of a guild within a given ecosystem could be competing for resources, such as space or light, while cooperating in resisting wind stresses, attracting pollinators, or detecting predators, such as happens among savannah-dwelling antelope and zebra.
A guild does not typically have strict, or even clearly defined boundaries, nor does it need to be taxonomically cohesive. A broadly defined guild will almost always have constituent guilds; for example, grazing guilds will have some species that concentrate on coarse, plentiful forage, while others concentrate on low-growing, finer plants. Each of those two sub-guilds may be regarded as guilds in appropriate contexts, and they might, in turn, have sub-guilds in more closely selective contexts. Some authorities even speak of guilds in terms of a fractal resource model. This concept arises in several related contexts, such as the metabolic theory of ecology, the scaling pattern of occupancy, and spatial analysis in ecology, all of which are fundamental concepts in defining guilds.
An ecological guild is not to be confused with a taxocene, a group of phylogenetically related organisms in a community that do not necessarily share the same or similar niches (for example, "the insect community"). Nor is a guild the same as a trophic species, which is a functional group of taxa sharing the same set of predators and prey within a food web.
Microbial guilds
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https://en.wikipedia.org/wiki/Purple%20Earth%20hypothesis | The Purple Earth hypothesis is an astrobiological hypothesis first proposed by Indian-American molecular biologist Shiladitya DasSarma in 2007, that the earliest photosynthetic life forms of Early Earth were based on the simpler molecule retinal rather than the more complex porphyrin-based chlorophyll, making the surface biosphere appear purplish rather its current greenish color. The time would date somewhere between 3.5 to 2.4 billion years ago, prior to the Great Oxygenation Event and Huronian glaciation.
Retinal-containing cell membrane exhibits a single light absorption peak centered in the energy-rich green-yellow region of the visible spectrum, but transmit and reflects red and blue light, resulting in a magenta color. Chlorophyll pigments, in contrast, absorb red and blue light, but little or no green light, which results in the characteristic green color of plants, green algae, cyanobacteria and other organisms with chlorophyllic organelles. The simplicity of retinal pigments in comparison to the more complex chlorophyll, their association with isoprenoid lipids in the cell membrane, as well as the discovery of archaeal membrane components in ancient sediments on the Early Earth are consistent with an early appearance of life forms with purple membrane prior to the turquoise of the Canfield ocean and later green photosynthetic organisms.
Evidence
The discovery of archaeal membrane components in ancient sediments on the Early Earth support the PEH.
Modern examples of retinal-based photosynthesis
An example of retinal-based organisms that exist today are photosynthetic microbes collectively called Haloarchaea. Many Haloarchaea contain the retinal derivative protein bacteriorhodopsin in their cell membrane, which carries out photon-driven proton pumping, generating a proton-motive gradient across the membrane and driving ATP synthesis. The process is a form of anoxygenic photosynthesis that does not involve carbon fixation, and the haloarchaeal membrane |
https://en.wikipedia.org/wiki/Commercially%20useful%20enzymes | Commercially useful enzymes (CUEs) are enzymes which have commercial uses. Microbial enzymes have well-known applications as biocatalysts in several areas of industry, such as biotechnology, agriculture, pharmaceuticals, etc. Metagenomic data provide a unique resource for discovering novel commercially useful enzymes (CUEs) from yet unidentified microbes belonging to complex microbial communities in diverse ecosystems.
Classification
A set of 510 CUEs was manually curated using publicly available information and classified into nine broad application categories based on their function. By comprehensive homology-based mining of ten diverse publicly available metagenomic data sources, several novel CUEs, homologous to those in the set of known CUEs, were identified. Using this strategy, a comprehensive Metagenomic BioMining Engine (MetaBioME) platform to facilitate homology-based computational identification of homologs for known CUEs from metagenomic datasets is developed. This is a useful resource to identify novel homologs to the existing known CUEs and to also identify new ones, both of which can be used as leads for further experimental verification.
This is available at MetaBioME. |
https://en.wikipedia.org/wiki/Abstract%20family%20of%20languages | In computer science, in particular in the field of formal language theory,
an abstract family of languages is an abstract mathematical notion generalizing characteristics common to the regular languages, the context-free languages and the recursively enumerable languages, and other families of formal languages studied in the scientific literature.
Formal definitions
A formal language is a set for which there exists a finite set of abstract symbols such that , where * is the Kleene star operation.
A family of languages is an ordered pair , where
is an infinite set of symbols;
is a set of formal languages;
For each in there exists a finite subset such that ; and
for some in .
A trio is a family of languages closed under homomorphisms that do not introduce the empty word, inverse homomorphisms, and intersections with a regular language.
A full trio, also called a cone, is a trio closed under arbitrary homomorphism.
A (full) semi-AFL is a (full) trio closed under union.
A (full) AFL is a (full) semi-AFL closed under concatenation and the Kleene plus.
Some families of languages
The following are some simple results from the study of abstract families of languages.
Within the Chomsky hierarchy, the regular languages, the context-free languages, and the recursively enumerable languages are all full AFLs. However, the context sensitive languages and the recursive languages are AFLs, but not full AFLs because they are not closed under arbitrary homomorphisms.
The family of regular languages are contained within any cone (full trio). Other categories of abstract families are identifiable by closure under other operations such as shuffle, reversal, or substitution.
Origins
Seymour Ginsburg of the University of Southern California and Sheila Greibach of Harvard University presented the first AFL theory paper at the IEEE Eighth Annual Symposium on Switching and Automata Theory in 1967.
Notes |
https://en.wikipedia.org/wiki/NCAR%20LSM%201.0 | The National Center for Atmospheric Research Land Surface Model (LSM) is a unidimensional computational model developed by Gordon Bonan that describes ecological processes joined in many ecosystem models, hydrological processes found in hydrological models and flow of surface common in surface models using atmospheric models.
In this way, the model examines interactions especially biogeophysics (sensible and latent heat, momentum, albedo, emission of long waves) and biogeochemistry (CO2) of the land-atmosphere the effect of surface of the land in the climate and composition of the atmosphere.
This model has a simplified treatment of the surface flows that reproduce at the very least computational cost the essential characteristics of the important interactions of the land-atmosphere for climatic simulations.
As the types of surface vegetated for some species are several, have a standardization of types of covering being enclosed surfaces covered with water as lakes (amongst others); thus the model wheel for each point of independent form, with the same average of the atmospheric interactions. The model functions in a space grating that can vary of a point until global. |
https://en.wikipedia.org/wiki/Peer%20Distributed%20Transfer%20Protocol | The Peer Distributed Transfer Protocol is an Internet file transfer protocol for distributing files from a central server across a peer-to-peer network. It is conceptually similar to BitTorrent but allows for streaming media. The protocol has been assigned port 6086 by the Internet Assigned Numbers Authority. The primary implementation is DistribuStream.
External links
PDTP protocol web site
PowerPoint Presentation
Network protocols |
https://en.wikipedia.org/wiki/Miracle%20Warriors%3A%20Seal%20of%20the%20Dark%20Lord | Miracle Warriors: Seal of the Dark Lord, known as in Japan, is a role-playing video game released initially on the Japanese PC-88 and then ported to various other systems, including a Master System port developed by Sega, which was released internationally.
Gameplay
Each screen of the game consists of four parts. In the lower left are all character statistics. It lists all characters in the party. Each character has a life bar and experience bar. A single character can gain experience by hitting enemies. Once the experiences is full, a new level is reached. The experience bar is emptied and both bars are extended, resulting in more maximum life for the character and more experience needed to gain a new level. On the lower right are statistics for the entire party (for example the amount of money).
The upper right section varies from screen to screen. While traveling the world, a town or a maze, a map is shown where the player can navigate. If the player invokes the main menu, it will be shown there. In battle it shows the battle menu. The upper left section also varies. While traveling the world or a cave it shows the party members and their surroundings. In battle it shows the foe and in town it shows persons to which the player can talk and their dialogue.
Once the player encounters an enemy, the screen switches to battle mode. In the battle mode, the player can choose one character to attack per turn. This character will also be subjected to the attack of the enemy, unless the enemy uses a spell that attacks multiple players. Some enemies can use flame spells to attack all party members or sleep spells that can put multiple party members to sleep. Every time a party member is put to sleep they take damage. They can wake up and be put to sleep many times during a battle, taking damage each time they fall asleep again. Once every party member is sleeping, the enemy will use a flame spell to attack every party member at once. As an alternative to attack, a play |
https://en.wikipedia.org/wiki/Q-Pochhammer%20symbol | In mathematical area of combinatorics, the q-Pochhammer symbol, also called the q-shifted factorial, is the product
with
It is a q-analog of the Pochhammer symbol , in the sense that
The q-Pochhammer symbol is a major building block in the construction of q-analogs; for instance, in the theory of basic hypergeometric series, it plays the role that the ordinary Pochhammer symbol plays in the theory of generalized hypergeometric series.
Unlike the ordinary Pochhammer symbol, the q-Pochhammer symbol can be extended to an infinite product:
This is an analytic function of q in the interior of the unit disk, and can also be considered as a formal power series in q. The special case
is known as Euler's function, and is important in combinatorics, number theory, and the theory of modular forms.
Identities
The finite product can be expressed in terms of the infinite product:
which extends the definition to negative integers n. Thus, for nonnegative n, one has
and
Alternatively,
which is useful for some of the generating functions of partition functions.
The q-Pochhammer symbol is the subject of a number of q-series identities, particularly the infinite series expansions
and
which are both special cases of the q-binomial theorem:
Fridrikh Karpelevich found the following identity (see for the proof):
Combinatorial interpretation
The q-Pochhammer symbol is closely related to the enumerative combinatorics of partitions. The coefficient of in
is the number of partitions of m into at most n parts.
Since, by conjugation of partitions, this is the same as the number of partitions of m into parts of size at most n, by identification of generating series we obtain the identity
as in the above section.
We also have that the coefficient of in
is the number of partitions of m into n or n-1 distinct parts.
By removing a triangular partition with n − 1 parts from such a partition, we are left with an arbitrary partition with at most n parts. This gives a weight-p |
https://en.wikipedia.org/wiki/Boolardy | Boolardy Station is a remote former sheep and cattle station in the Mid West (Murchison) region of Western Australia, about north-north-east of Pindar and west-south-west of Meekatharra. It is within the Shire of Murchison and situated on pastoral lease no. 3114/406 (Crown lease 146/1966). The area of the lease is .
In 2009 the CSIRO (Commonwealth Scientific and Industrial Research Organisation) purchased the property for , in order to provide the location of the Murchison Radio-astronomy Observatory, while the owners continued running the property as a cattle station until around 2014.
Description
An area of within the station was composed of reserves and crown land. In 2011 a report stated that the soil had a low level of erosion, with 87% of the land being described as nil or minor. The perennial vegetation condition was fair, with 39% of vegetation cover being described as poor or very poor.
The property was an important pastoral property in the Murchison region, with the Boolardy Homestead used as offices of the Murchison Road Board for many years.
The station's western boundary is bordered by Wooleen Station.
The various stone buildings of Boolardy Station were classified by the National Trust of Western Australia on 2 September 1985.
History
Robert Austin and Kenneth Brown explored the region in 1854, noting the rich grassy plains of Boolardy and importantly, the Ngatta water hole. However, the potential of the area was not appreciated until 1873 when John Perks and Edward Wittenoom explored the area north of the water hole while searching for sheep grazing country. The water hole is about south of the main homestead.
Perks and Wittenoom subsequently took up the initial lease and the first cattle and sheep were taken overland to Nookawarra in 1876, but as the site lacked suitable feed for horses, they moved to the Boolardy site. The lease was later associated with various members of the pioneering Wittenoom and Lefroy families, particularly |
https://en.wikipedia.org/wiki/Interleaved%20polling%20with%20adaptive%20cycle%20time | Interleaved polling with adaptive cycle time (IPACT) is an algorithm designed by Glen Kramer, Biswanath Mukherjee and Gerry Pesavento of the Advanced Technology Lab at the University of California, Davis in 2002. IPACT is a dynamic bandwidth allocation algorithm for use in Ethernet passive optical networks (EPONs).
IPACT uses the Gate and Report messages provided by the EPON Multi-Point Control Protocol (MPCP) to allocate bandwidth to Optical Network Units (ONUs). If the optical line terminal grants bandwidth to an ONU and waits until it has received that particular ONU's transmission before granting bandwidth to another ONU, then time equivalent to a whole messaging round-trip is wasted during which the upstream may remain idle. IPACT eliminates this idle time by sending downstream grant messages to succeeding ONUs while receiving transmissions from previously granted ONUs. It accomplishes this by calculating the time at which a transmission grant allocated to a previous ONU ends. |
https://en.wikipedia.org/wiki/List%20of%20HDL%20simulators | HDL simulators are software packages that simulate expressions written in one of the hardware description languages, such as VHDL, Verilog, SystemVerilog.
This page is intended to list current and historical HDL simulators, accelerators, emulators, etc.
Proprietary simulators
Some commercial proprietary simulators (such as ModelSim) are available in student, or evaluation/demo editions. These editions generally have many features disabled, arbitrary limits on simulation design size, but are sometimes offered free of charge.
Free and open-source simulators
Verilog simulators
VHDL simulators
Key
See also
Verilog
SystemVerilog
VHDL
SystemC
Waveform viewer |
https://en.wikipedia.org/wiki/Bandwidth%20guaranteed%20polling | Bandwidth Guaranteed Polling (BGP) in computing and telecommunications is a dynamic bandwidth allocation algorithm for Ethernet passive optical networks designed by Maode Ma et al. at the National University of Singapore. This is an instance of an algorithm that allocates bandwidth based on fixed weights.
BGP divides a window of time into fixed-sized slots, a number of which are allocated to each Optical Network Unit (ONU). The number allocated depends upon the ONU customer's service level agreement (SLA). If an ONU does not wish to use its entire allocated time slot, it may inform the OLT about this. The OLT may then decide to reallocate the remaining time slot to another ONU which does not have an SLA.
The BGP algorithm may not be entirely compatible with the MPCP standard. This is because the MPCP does not provide any way for the ONU to inform the OLT about the fraction of the time slot that it wishes to use. |
https://en.wikipedia.org/wiki/Impulse%20invariance | Impulse invariance is a technique for designing discrete-time infinite-impulse-response (IIR) filters from continuous-time filters in which the impulse response of the continuous-time system is sampled to produce the impulse response of the discrete-time system. The frequency response of the discrete-time system will be a sum of shifted copies of the frequency response of the continuous-time system; if the continuous-time system is approximately band-limited to a frequency less than the Nyquist frequency of the sampling, then the frequency response of the discrete-time system will be approximately equal to it for frequencies below the Nyquist frequency.
Discussion
The continuous-time system's impulse response, , is sampled with sampling period to produce the discrete-time system's impulse response, .
Thus, the frequency responses of the two systems are related by
If the continuous time filter is approximately band-limited (i.e. when ), then the frequency response of the discrete-time system will be approximately the continuous-time system's frequency response for frequencies below π radians per sample (below the Nyquist frequency 1/(2T) Hz):
for
Comparison to the bilinear transform
Note that aliasing will occur, including aliasing below the Nyquist frequency to the extent that the continuous-time filter's response is nonzero above that frequency. The bilinear transform is an alternative to impulse invariance that uses a different mapping that maps the continuous-time system's frequency response, out to infinite frequency, into the range of frequencies up to the Nyquist frequency in the discrete-time case, as opposed to mapping frequencies linearly with circular overlap as impulse invariance does.
Effect on poles in system function
If the continuous poles at , the system function can be written in partial fraction expansion as
Thus, using the inverse Laplace transform, the impulse response is
The corresponding discrete-time system's impulse response is th |
https://en.wikipedia.org/wiki/List%20of%20palindromic%20places | A palindromic place is a city or town whose name can be read the same forwards or backwards. An example of this would be Navan in Ireland. Some of the entries on this list are only palindromic if the next administrative division they are a part of is also included in the name, such as Adaven, Nevada.
Issues
Because the names here come from a variety of languages, several issues arise.
Unbalanced diacritics
Diacritics are marks placed on or near letters to give them a modified pronunciation. Some languages treat such as completely different letters; others treat them as variants of the base letter. The latter group is summarized here. Only place names where the language of the country is in the latter group are included here when diacritics make for an apparent non-palindrome.
Turkic vowels
Some Turkic languages (Turkish, Azerbaijan, Kazakh) have two or more vowels that resemble the I. They are differentiated by the number of dots above the letter: zero, one, or two. These dots appear on both lower and upper case letters. For places in Turkey, Azerbaijan, and Kazakhstan, only those vowels that have the same number of dots will be considered equal here.
ʻOkina in Polynesian languages
The ʻokina is a consonant found in several Polynesian languages. It is pronounced as a glottal stop and is often represented by an apostrophe when the correct character ʻ is not available. Because English wordplay generally ignores apostrophes, it is common to ignore ʻokinas in deciding whether a Polynesian name is a palindrome. However, this list does not follow that rule. Unbalanced ʻokinas will not be found in this list. However that rule has not been applied consistently to the Arabic hamza, which also represents a glottal stop.
Palindromic place names
Palindromatic place names in the Latin alphabet are:
12 letters
Adaven, Nevada, United States
Adanac, Canada (Nipissing District, Ontario)
Adanac, Canada (Parry Sound District, Ontario)
Adanac, Canada (Saskatchewan)
11 letters
Wa |
https://en.wikipedia.org/wiki/Conway%20base%2013%20function | The Conway base 13 function is a function created by British mathematician John H. Conway as a counterexample to the converse of the intermediate value theorem. In other words, it is a function that satisfies a particular intermediate-value property—on any interval (a, b), the function f takes every value between f(a) and f(b)—but is not continuous.
In 2018, a much simpler function with the property that every open set is mapped onto the full real line was constructed by Aksel Bergfeldt. This function is also nowhere continuous.
Purpose
The Conway base 13 function was created as part of a "produce" activity: in this case, the challenge was to produce a simple-to-understand function which takes on every real value in every interval, that is, it is an everywhere surjective function. It is thus discontinuous at every point.
Sketch of definition
Every real number x can be represented in base 13 in a unique canonical way; such representations use the digits 0–9 plus three additional symbols, say {A, B, C}. For example, the number 54349589 has a base-13 representation B34C128.
If instead of {A, B, C}, we judiciously choose the symbols {+, −, .}, something interesting happens: some numbers in base 13 will have representations that look like well-formed decimals in base 10: for example, the number 54349589 has a base-13 representation of −34.128. Of course, most numbers will not be intelligible in this way; for example, the number 3629265 has the base-13 representation 9+0−−7.
Conway's base-13 function takes in a real number x and considers its base-13 representation as a sequence of symbols . If from some position onward, the representation looks like a well-formed decimal number r, then f(x) = r. Otherwise, f(x) = 0. (Well-formed means that it starts with a + or − symbol, contains exactly one decimal-point symbol, and otherwise contains only the digits 0–9). For example, if a number x has the representation 8++2.19+0−−7+3.141592653..., then f(x) = +3.1415926 |
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