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https://en.wikipedia.org/wiki/DrayTek | DrayTek () is a network equipment manufacturer of broadband CPE (Customer Premises Equipment), including firewalls, VPN devices, routers, managed switches and wireless LAN devices. The company was founded in 1997. The earliest products included ISDN based solutions, the first being the ISDN Vigor128, a USB terminal adaptor for Windows and Mac OS. This was followed by the ISDN Vigor204 ISDN terminal adaptor/PBX and the Vigor2000, its first router. The head office is located in Hsinchu, Taiwan with regional offices and distributors worldwide.
DrayTek's products cover a wide solution range such as firewall, VPN, VoIP, xDSL/broadband devices, and management software to meet the market trend, go above and beyond customers' expectations.
DrayTek was one of the first manufacturers to bring VPN technology to low cost routers, increasing the viability of remote work. In 2004, DrayTek released the first of its VoIP (Voice-Over-IP) products. In 2006, new products for companies debuted, including larger scale firewalls and Unified Threat Management (UTM) firewalls products however the UTM Firewalls did not sell in sufficient volume and the UTM products ceased development and production.
DrayTek's product line offers business and consumer DSL modems with support for the PPPoA standard compared to the more widely supported PPPoE for use with full-featured home routers and home computers without more expensive ATM hardware. PPPoA is used primarily in the UK for ADSL lines. Most Vigor routers provide a virtual private network (VPN) feature, provides LAN-to-LAN and Remote-Dial-In Connections. In 2011, DrayTek embedded SSL VPN facilities into VigorRouter Series.
DrayTek's Initial Public Offering (IPO) on the Taiwan Stock Exchange occurred in 2004.
March 2021 DrayTek releases new WiFi 6 Access Point to market - DrayTek AP1060C
August 2021 DrayTek announces 2 new WiFi 6 Routers - DrayTek Vigor 2927ax & DrayTek Vigor 2865ax |
https://en.wikipedia.org/wiki/Test%20and%20test-and-set | In computer architecture, the test-and-set CPU instruction (or instruction sequence) is designed to implement
mutual exclusion in multiprocessor environments. Although a correct lock can be implemented with test-and-set, the test and test-and-set optimization lowers resource contention caused by bus locking, especially cache coherency protocol overhead on contended locks.
Given a lock:
boolean locked := false // shared lock variable
the entry protocol is:
procedure EnterCritical() {
do {
while ( locked == true )
skip // spin using normal instructions until the lock is free
} while ( TestAndSet(locked) == true ) // attempt actual atomic locking using the test-and-set instruction
}
and the exit protocol is:
procedure ExitCritical() {
locked := false
}
The difference to the simple test-and-set protocol is the additional spin-loop (the test in test and test-and-set) at the start of the entry protocol, which utilizes ordinary load instructions. The load in this loop executes with less overhead compared to an atomic operation (resp. a load-exclusive instruction). E.g., on a system utilizing the MESI cache coherency protocol, the cache line being loaded is moved to the Shared state, whereas a test-and-set instruction or a load-exclusive instruction moves it into the Exclusive state.
This is particularly advantageous if multiple processors are contending for the same lock: whereas an atomic instruction or load-exclusive instruction requires a coherency-protocol transaction to give that processor exclusive access to the cache line (causing that line to ping-pong between the involved processors), ordinary loads on a line in Shared state require no protocol transactions at all: processors spinning in the inner loop operate purely locally.
Cache-coherency protocol transactions are used only in the outer loop, after the initial check has ascertained that they have a reasonable likelihood of success.
If the programming language used support |
https://en.wikipedia.org/wiki/Direct%20sum | The direct sum is an operation between structures in abstract algebra, a branch of mathematics. It is defined differently, but analogously, for different kinds of structures. To see how the direct sum is used in abstract algebra, consider a more elementary kind of structure, the abelian group. The direct sum of two abelian groups and is another abelian group consisting of the ordered pairs where and . To add ordered pairs, we define the sum to be ; in other words addition is defined coordinate-wise. For example, the direct sum , where is real coordinate space, is the Cartesian plane, . A similar process can be used to form the direct sum of two vector spaces or two modules.
We can also form direct sums with any finite number of summands, for example , provided and are the same kinds of algebraic structures (e.g., all abelian groups, or all vector spaces). This relies on the fact that the direct sum is associative up to isomorphism. That is, for any algebraic structures , , and of the same kind. The direct sum is also commutative up to isomorphism, i.e. for any algebraic structures and of the same kind.
The direct sum of finitely many abelian groups, vector spaces, or modules is canonically isomorphic to the corresponding direct product. This is false, however, for some algebraic objects, like nonabelian groups.
In the case where infinitely many objects are combined, the direct sum and direct product are not isomorphic, even for abelian groups, vector spaces, or modules. As an example, consider the direct sum and direct product of (countably) infinitely many copies of the integers. An element in the direct product is an infinite sequence, such as (1,2,3,...) but in the direct sum, there is a requirement that all but finitely many coordinates be zero, so the sequence (1,2,3,...) would be an element of the direct product but not of the direct sum, while (1,2,0,0,0,...) would be an element of both. Often, if a + sign is used, all but finitely many c |
https://en.wikipedia.org/wiki/G%C3%B6del%20metric | The Gödel metric, also known as the Gödel solution or Gödel universe, is an exact solution, found in 1949 by Kurt Gödel, of the Einstein field equations in which the stress–energy tensor contains two terms: the first representing the matter density of a homogeneous distribution of swirling dust particles (dust solution), and the second associated with a negative cosmological constant (see Lambdavacuum solution).
This solution has many unusual properties—in particular, the existence of closed time-like curves that would allow time travel in a universe described by the solution. Its definition is somewhat artificial, since the value of the cosmological constant must be carefully chosen to correspond to the density of the dust grains, but this spacetime is an important pedagogical example.
Definition
Like any other Lorentzian spacetime, the Gödel solution represents the metric tensor in terms of a local coordinate chart. It may be easiest to understand the Gödel universe using the cylindrical coordinate system (see below), but this article uses the chart originally used by Gödel. In this chart, the metric (or, equivalently, the line element) is
where is a non-zero real constant that gives the angular velocity of the surrounding dust grains about the y-axis, measured by a "non-spinning" observer riding on one of the dust grains. "Non-spinning" means that the observer does not feel centrifugal forces, but in this coordinate system, it would rotate about an axis parallel to the y-axis. In this rotating frame, the dust grains remain at constant values of x, y, and z. Their density in this coordinate diagram increases with x, but their density in their own frames of reference is the same everywhere.
Properties
To investigate the properties of the Gödel solution, the frame field can be assumed (dual to the co-frame read from the metric as given above),
This framework defines a family of inertial observers that are 'comoving with the dust grains'. The computation of the |
https://en.wikipedia.org/wiki/Salvia%20%27Celestial%20Blue%27 | Salvia 'Celestial Blue' (also known as celestial blue sage or Las Pilitas sage), is a hybrid cross between Salvia clevelandii (Cleveland sage or chaparral sage) and S. pachyphylla (Rose's sage or mountain desert sage), and possibly involving Salvia 'Pozo Blue' — which is itself a cross between S. clevelandii and S. leucophylla (purple sage). The hybrid parents are native to California.
The plant is a perennial evergreen, with a rounded growth habit and a moderate growth rate. It can tolerate full sun and is adaptable to numerous soil conditions, and is cold hardy down to 15°F.
The foliage smells of musk, and the large, pale violet to periwinkle blue flowers are attractive to bees, hummingbirds, and butterflies. An extremely drought- and heat-tolerant plant, introduced by Las Pilitas, a California native plant nursery, in 1999. It is cultivated in gardens and public landscapes. |
https://en.wikipedia.org/wiki/Diffusing%20update%20algorithm | The diffusing update algorithm (DUAL) is the algorithm used by Cisco's EIGRP routing protocol to ensure that a given route is recalculated globally whenever it might cause a routing loop. It was developed by J.J. Garcia-Luna-Aceves at SRI International. The full name of the algorithm is DUAL finite-state machine (DUAL FSM). EIGRP is responsible for the routing within an autonomous system, and DUAL responds to changes in the routing topology and dynamically adjusts the routing tables of the router automatically.
EIGRP uses a feasibility condition to ensure that only loop-free routes are ever selected. The feasibility condition is conservative: when the condition is true, no loops can occur, but the condition might under some circumstances reject all routes to a destination although some are loop-free.
When no feasible route to a destination is available, the DUAL algorithm invokes a diffusing computation to ensure that all traces of the problematic route are eliminated from the network. At which point the normal Bellman–Ford algorithm is used to recover a new route.
Operation
DUAL uses three separate tables for the route calculation. These tables are created using information exchanged between the EIGRP routers. The information is different than that exchanged by link-state routing protocols. In EIGRP, the information exchanged includes the routes, the "metric" or cost of each route, and the information required to form a neighbor relationship (such as AS number, timers, and K values). The three tables and their functions in detail are as follows:
Neighbor table contains information on all other directly connected routers. A separate table exists for each supported protocol (IP, IPX, etc.). Each entry corresponds to a neighbour with the description of network interface and address. In addition, a timer is initialized to trigger the periodic detection of whether the connection is alive. This is achieved through "Hello" packets. If a "Hello" packet is not recei |
https://en.wikipedia.org/wiki/Artin%27s%20conjecture%20on%20primitive%20roots | In number theory, Artin's conjecture on primitive roots states that a given integer a that is neither a square number nor −1 is a primitive root modulo infinitely many primes p. The conjecture also ascribes an asymptotic density to these primes. This conjectural density equals Artin's constant or a rational multiple thereof.
The conjecture was made by Emil Artin to Helmut Hasse on September 27, 1927, according to the latter's diary. The conjecture is still unresolved as of 2023. In fact, there is no single value of a for which Artin's conjecture is proved.
Formulation
Let a be an integer that is not a square number and not −1. Write a = a0b2 with a0 square-free. Denote by S(a) the set of prime numbers p such that a is a primitive root modulo p. Then the conjecture states
S(a) has a positive asymptotic density inside the set of primes. In particular, S(a) is infinite.
Under the conditions that a is not a perfect power and that a0 is not congruent to 1 modulo 4 , this density is independent of a and equals Artin's constant, which can be expressed as an infinite product
.
Similar conjectural product formulas exist for the density when a does not satisfy the above conditions. In these cases, the conjectural density is always a rational multiple of CArtin.
Example
For example, take a = 2. The conjecture claims that the set of primes p for which 2 is a primitive root has the above density CArtin. The set of such primes is
S(2) = {3, 5, 11, 13, 19, 29, 37, 53, 59, 61, 67, 83, 101, 107, 131, 139, 149, 163, 173, 179, 181, 197, 211, 227, 269, 293, 317, 347, 349, 373, 379, 389, 419, 421, 443, 461, 467, 491, ...}.
It has 38 elements smaller than 500 and there are 95 primes smaller than 500. The ratio (which conjecturally tends to CArtin) is 38/95 = 2/5 = 0.4.
Partial results
In 1967, Christopher Hooley published a conditional proof for the conjecture, assuming certain cases of the generalized Riemann hypothesis.
Without the generalized Riemann hypothesis, there is |
https://en.wikipedia.org/wiki/Hermite%20interpolation | In numerical analysis, Hermite interpolation, named after Charles Hermite, is a method of polynomial interpolation, which generalizes Lagrange interpolation. Lagrange interpolation allows computing a polynomial of degree less than that takes the same value at given points as a given function. Instead, Hermite interpolation computes a polynomial of degree less than such that the polynomial and its first derivatives have the same values at given points as a given function and its first derivatives.
Hermite's method of interpolation is closely related to the Newton's interpolation method, in that both are derived from the calculation of divided differences. However, there are other methods for computing a Hermite interpolating polynomial. One can use linear algebra, by taking the coefficients of the interpolating polynomial as unknowns, and writing as linear equations the constraints that the interpolating polynomial must satisfy. For another method, see .
Statement of the problem
Hermite interpolation consists of computing a polynomial of degree as low as possible that matches an unknown function both in observed value, and the observed value of its first derivatives. This means that values
must be known. The resulting polynomial has a degree less than . (In a more general case, there is no need for to be a fixed value; that is, some points may have more known derivatives than others. In this case the resulting polynomial has a degree less than the number of data points.)
Let us consider a polynomial of degree less than with indeterminate coefficients; that is, the coefficients of are new variables. Then, by writing the constraints that the interpolating polynomial must satisfy, one gets a system of linear equations in unknowns.
In general, such a system has exactly one solution. Charles Hermite proved that this is effectively the case here, as soon as the are pairwise different, and provided a method for computing it, which is described below. |
https://en.wikipedia.org/wiki/Otolith | An otolith (, ear + , , a stone), also called statoconium or otoconium or statolith, is a calcium carbonate structure in the saccule or utricle of the inner ear, specifically in the vestibular system of vertebrates. The saccule and utricle, in turn, together make the otolith organs. These organs are what allows an organism, including humans, to perceive linear acceleration, both horizontally and vertically (gravity). They have been identified in both extinct and extant vertebrates.
Counting the annual growth rings on the otoliths is a common technique in estimating the age of fish.
Description
Endolymphatic infillings such as otoliths are structures in the saccule and utricle of the inner ear, specifically in the vestibular labyrinth of all vertebrates (fish, amphibians, reptiles, mammals and birds). In vertebrates, the saccule and utricle together make the otolith organs. Both statoconia and otoliths are used as gravity, balance, movement, and directional indicators in all vertebrates and have a secondary function in sound detection in higher aquatic and terrestrial vertebrates. They are sensitive to gravity and linear acceleration. Because of their orientation in the head, the utricle is sensitive to a change in horizontal movement, and the saccule gives information about vertical acceleration (such as when in an elevator).
Similar balance receptors called statocysts can be found in many invertebrate groups but are not contained in the structure of an inner ear. Mollusk statocysts are of a similar morphology to the displacement-sensitive organs of vertebrates; however, the function of the mollusk statocyst is restricted to gravity detection and possibly some detection of angular momentum. These are analogous structures, with similar form and function but not descended from a common structure.
Statoconia (also called otoconia) are numerous grains, often spherical in shape, between 1 and 50 µm; collectively. Statoconia are also sometimes termed a statocyst. Oto |
https://en.wikipedia.org/wiki/Flag%20%28programming%29 | In computer programming, flag can refer to one or more bits that are used to store a binary value or a Boolean variable for signaling special code conditions, such as file empty or full queue statuses.
Flags may be found as members of a defined data structure, such as a database record, and the meaning of the value contained in a flag will generally be defined in relation to the data structure it is part of. In many cases, the binary value of a flag will be understood to represent one of several possible states or statuses. In other cases, the binary values may represent one or more attributes in a bit field, often related to abilities or permissions, such as "can be written to" or "can be deleted". However, there are many other possible meanings that can be assigned to flag values. One common use of flags is to mark or designate data structures for future processing.
Within microprocessors and other logic devices, flags are commonly used to control or indicate the intermediate or final state or outcome of different operations. Microprocessors typically have, for example, a status register that is composed of such flags, and the flags are used to indicate various post-operation conditions, such as when there has been an arithmetic overflow. The flags can be utilized in subsequent operations, such as in processing conditional jump instructions. For example a je (Jump if Equal) instruction in the X86 assembly language will result in a jump if the Z (zero) flag was set by some previous operation.
A command line switch is also referred to as a flag. Command line programs often start with an option parser that translates command line switches into flags in the sense of this article.
See also
Bit field
Control register
Enumerated type
FLAGS register (computing)
Flag byte
Program status word
Semaphore (programming)
Status register |
https://en.wikipedia.org/wiki/Perpendicular%20recording | Perpendicular recording (or perpendicular magnetic recording, PMR), also known as conventional magnetic recording (CMR), is a technology for data recording on magnetic media, particularly hard disks. It was first proven advantageous in 1976 by Shun-ichi Iwasaki, then professor of the Tohoku University in Japan, and first commercially implemented in 2005. The first industry-standard demonstration showing unprecedented advantage of PMR over longitudinal magnetic recording (LMR) at nanoscale dimensions was made in 1998 at IBM Almaden Research Center in collaboration with researchers of Data Storage Systems Center (DSSC) – a National Science Foundation (NSF) Engineering Research Center (ERCs) at Carnegie Mellon University (CMU).
Advantages
Perpendicular recording can deliver more than three times the storage density of traditional longitudinal recording. In 1986, Maxell announced a floppy disk using perpendicular recording that could store . Perpendicular recording was later used by Toshiba in 3.5" floppy disks in 1989 to permit 2.88 MB of capacity (ED or extra-high density), but they failed to succeed in the marketplace. Since about 2005, the technology has come into use for hard disk drives. Hard disk technology with longitudinal recording has an estimated limit of due to the superparamagnetic effect, though this estimate is constantly changing. Perpendicular recording is predicted to allow information densities of up to around . , drives with densities of were available commercially. In 2016 the commercially available density was at least . In late 2021 the Seagate disk with the highest density was a consumer-targeted 2.5" BarraCuda. It used density. Other disks from the manufacturer used and .
Technology
The main challenge in designing magnetic information storage media is to retain the magnetization of the medium despite thermal fluctuations caused by the superparamagnetic limit. If the thermal energy is too high, there may be enough energy to reverse th |
https://en.wikipedia.org/wiki/Springburn%20Museum | Springburn Museum was set up in the reading room of the Springburn Library, Glasgow, Scotland, as the first independent community museum in the city, presenting material on the industrial heritage of the area.
The Museum was opened by Tom Weir in 1986. It continued to provide a community based resource for historical reference throughout the 1990s. After encountering financial difficulties, the Museum closed in 2001. Subsequently, a more limited display in Springburn Library is complemented by an online entity.
Plans for redeveloping Springburn Winter Gardens announced in 2020 would include some artefacts formerly exhibited at the Museum. |
https://en.wikipedia.org/wiki/Integrated%20amplifier | An integrated amplifier (pre/main amp) is an electronic device containing an audio preamplifier and power amplifier in one unit, as opposed to separating the two. Most modern audio amplifiers are integrated and have several inputs for devices such as CD players, DVD players, and auxiliary sources.
Vintage integrated amplifiers commonly have dedicated inputs for phonograph, tuner, tape recorder and/or an auxiliary input. Except for the phono input, all of the inputs are line level, thus, they are interchangeable. The phono preamplifier stage provides RIAA equalization.
See also
Audiophile
High-end audio
High fidelity
Valve audio amplifier |
https://en.wikipedia.org/wiki/Fibred%20category | Fibred categories (or fibered categories) are abstract entities in mathematics used to provide a general framework for descent theory. They formalise the various situations in geometry and algebra in which inverse images (or pull-backs) of objects such as vector bundles can be defined. As an example, for each topological space there is the category of vector bundles on the space, and for every continuous map from a topological space X to another topological space Y is associated the pullback functor taking bundles on Y to bundles on X. Fibred categories formalise the system consisting of these categories and inverse image functors. Similar setups appear in various guises in mathematics, in particular in algebraic geometry, which is the context in which fibred categories originally appeared. Fibered categories are used to define stacks, which are fibered categories (over a site) with "descent". Fibrations also play an important role in categorical semantics of type theory, and in particular that of dependent type theories.
Fibred categories were introduced by , and developed in more detail by .
Background and motivations
There are many examples in topology and geometry where some types of objects are considered to exist on or above or over some underlying base space. The classical examples include vector bundles, principal bundles, and sheaves over topological spaces. Another example is given by "families" of algebraic varieties parametrised by another variety. Typical to these situations is that to a suitable type of a map between base spaces, there is a corresponding inverse image (also called pull-back) operation taking the considered objects defined on to the same type of objects on . This is indeed the case in the examples above: for example, the inverse image of a vector bundle on is a vector bundle on .
Moreover, it is often the case that the considered "objects on a base space" form a category, or in other words have maps (morphisms) between them. In |
https://en.wikipedia.org/wiki/Alfred%20O%27Rahilly | Alfred O'Rahilly, KSG (1 October 1884 – 1 August 1969) was an academic with controversial views on both electromagnetism and religion. He briefly served in politics, as a Teachta Dála (TD) for Cork City, and was later the president of University College Cork. He also became a priest following the death of his wife.
Education and academia
Born (with the last name Rahilly) in Listowel, County Kerry, Ireland to Thomas Francis Rahilly of Ballylongford, County Kerry and Julia Mary Rahilly (née Curry) of Glin, County Limerick.
He was first educated at St Michael's College, Listowel and at Blackrock College in Dublin. O'Rahilly first earned University College Cork degrees in mathematical physics (BA 1907, MA 1908).
He studied scholastic philosophy at Stonyhurst College in Lancashire following his master's degree, then returned to UCC for a BSc (1912). In 1914, he was appointed assistant lecturer in the Department of Mathematics and Mathematical Physics at UCC, and then in 1917 he was made Professor of Mathematical Physics.
In 1919 he received a doctorate from the Pontifical Gregorian University in Rome. He became Registrar of UCC in 1920, and held the post until 1943 when he became President of the University. O'Rahilly founded Cork University Press in 1925. He spent a year, in 1927, at Harvard studying social and political theory.
In 1938, he published a controversial book surveying electromagnetic theory called Electromagnetics (Longman, Green and Company), republished in 1956 by Dover as Electromagnetic theory, a critical examination of fundamentals.
In 1939, UCC conferred on him the degree D.Litt., and in 1940 the National University of Ireland awarded him a DSc.
The O'Rahilly Building was one of the major developments on the UCC campus in the 1990s and was named in honour of O'Rahilly.
Politics and public life
After the 1916 Easter Rising, O'Rahilly publicly supported Sinn Féin and was elected to Cork City Council as a Sinn Féin and Transport Workers candi |
https://en.wikipedia.org/wiki/Charles%20Darwin%27s%20education | Charles Darwin's education gave him a foundation in the doctrine of Creation prevalent throughout the West at the time, as well as knowledge of medicine and theology. More significantly, it led to his interest in natural history, which culminated in his taking part in the second voyage of HMS Beagle and the eventual inception of his theory of natural selection. Although Darwin changed his field of interest several times in these formative years, many of his later discoveries and beliefs were foreshadowed by the influences he had as a youth.
Background and influences
A child of the early 19th century, Charles Robert Darwin grew up in a conservative era when repression of revolutionary Radicalism had displaced the 18th century Enlightenment. The Church of England dominated the English scientific establishment. The Church saw natural history as revealing God's underlying plan and as supporting the existing social hierarchy. It rejected Enlightenment philosophers such as David Hume who had argued for naturalism and against belief in God.
The discovery of fossils of extinct species was explained by theories such as catastrophism. Catastrophism claimed that animals and plants were periodically annihilated as a result of natural catastrophes and then replaced by new species created ex nihilo (out of nothing). The extinct organisms could then be observed in the fossil record, and their replacements were considered to be immutable.
Darwin's extended family of Darwins and Wedgwoods was strongly Unitarian. One of Darwin's grandfathers, Erasmus Darwin, was a successful physician, and was followed in this by his sons Charles Darwin, who died in 1778 while still a promising medical student at the University of Edinburgh, and Doctor Robert Waring Darwin, Darwin's father, who named his son Charles Robert Darwin, honouring his deceased brother.
Erasmus was a freethinker who hypothesized that all warm-blooded animals sprang from a single living "filament" long, long ago. He furt |
https://en.wikipedia.org/wiki/Now%20I%20Lay%20Me%20Down%20to%20Sleep | Now I lay me down to sleep is a Christian children's bedtime prayer from the 18th century.
Text
Perhaps the earliest version was written by George Wheler in his 1698 book The Protestant Monastery, which reads:
Upon lying down, and going to sleep.
Here I lay me down to sleep.
To thee, O Lord, I give my Soul to keep,
Wake I ever, Or, Wake I never;
To thee O Lord, I give my Soul to keep for ever.
A later version printed in The New England Primer goes:
Now I lay me down to sleep,
I pray the Lord my Soul to keep[;]
If I should die before I 'wake,
I pray the Lord my Soul to take.
Other versions
Grace Bridges, 1932:
Now I lay me down to sleep,
I pray my lord my soul to keep,
In the morn when I awake
Please teach me the path of life to take.
Now I lay me down to sleep,
I pray the Lord my soul to keep;
His Love to guard me through the night,
And wake me in the morning's light amen.
Now I lay me down to sleep,
I pray the Lord my soul to keep;
Please angels watch me through the night,
And keep me safe till morning light.
Now I lay me down to sleep,
I pray the Lord my soul to keep;
Angels watch me through the night,
And wake me with the morning light.
Amen
Now I wake to see the light,
As God has kept me through the night;
And now I lift my voice to pray,
That Thou wilt keep me through the day.
Now I lay me down to sleep,
I pray the Lord my soul to keep,
See me safely through the night,
And wake me with the morning light. Amen.
It is sometimes combined with the "Black Paternoster", one version of which goes:
Matthew, Mark, Luke and John,
Bless the bed that I lie on.
Four corners to my bed,
Four angels round my head;
One to watch and one to pray
And two to bear my soul away.
In popular culture
Music
Musician Will Wood uses the line "As I lay me down to sleep" in their song "Tomcat Disposables"
American thrash metal band Megadeth uses this prayer in their 1991 song "Go to Hell".
The final verse of Ron Miller's "Heaven Help Us All", first recorded and released by S |
https://en.wikipedia.org/wiki/Ames%20strain | The Ames strain is one of 89 known strains of the anthrax bacterium (Bacillus anthracis). It was isolated from a diseased 14-month-old Beefmaster heifer that died in Sarita, Texas in 1981. The strain was isolated at the Texas Veterinary Medical Diagnostic Laboratory and a sample was sent to the United States Army Medical Research Institute of Infectious Diseases (USAMRIID). Researchers at USAMRIID mistakenly believed the strain came from Ames, Iowa because the return address on the package was the USDA's National Veterinary Services Laboratories in Ames and mislabeled the specimen.
The Ames strain came to wide public attention during the 2001 anthrax attacks when seven letters containing it were mailed to media outlets and US Senators on September 18, 2001, and October 9, 2001.
Because of its virulence, the Ames strain is used by the United States for developing vaccines and testing their effectiveness. Use of the Ames strain started in the 1980s, after work on weaponizing the Vollum 1B strain ended and all weaponized stocks were destroyed after the end of the U.S. biological warfare program in 1969.
Virulence
Virulence plasmids
Researchers have identified two specific virulence plasmids in B. anthracis, with the Ames strain expressing greater virulence compared to other strains. The virulence of B. anthracis results from two plasmids, pXO1 and pXO2. Plasmid pXO2 encodes an antiphagocytic poly-D-glutamic acid capsule, which allows B. anthracis to evade the host immune system. Plasmid pXO1 encodes three toxin proteins: edema factor (EF), lethal factor (LF) and protective antigen (PA). Variation in virulence can be explained by the presence or absence of plasmids; for example, isolates missing either pXO1 or pXO2 are considered attenuated, meaning they will not cause significant infection. One possible mechanism that may be responsible for the regulation of virulence is the copy number of plasmids per cell. The number of plasmids among isolates varies, with as m |
https://en.wikipedia.org/wiki/Tomoe | , commonly translated as "comma", is a comma-like swirl symbol used in Japanese (roughly equivalent to a heraldic badge or charge in European heraldry). It closely resembles the usual form of a .
The appears in many designs with various uses. The simplest, most common patterns of the device contain from one to four , and are reminiscent of similar designs that have been found in wide distribution around the world. When circumscribed in a circle, it often appears in a set of three, with this design known as the .
Etymology
The character 巴 (Chinese pronunciation bā) has several meanings, ranging from a Sichuan toponym to a crust formed by dryness, parts of the body such as hands or cheeks, and, as a verb, bearing the sense of "to hope", "expect" or "be anxious over". The Chinese character used to depict, according to Bernhard Karlgren's interpretation of the small seal script graph, a python. The Japanese word itself may be of Mongolic origin, since it bears comparison with Middle Mongol "twisted horse headdress", from the verb (plait, twist), and Ordos Mongolian t'omok ('a little bag hung on a horse's head'). In this latter connection Tang ceramic figures of horses show small sacks tethered to the lower neck, perhaps to stop the horse from throwing its head back.
One view is that the word refers to a picture of a , or drawings on the latter, the in question, in archaic Japanese , being a round leather arm protector, like the bracer or gauntlet tab of European archery. Roy Andrew Miller describes it as "a small hollow sack or bulb of sewn leather with leather tie straps, sometimes embossed with a comma like decorative device () of continental origin". It was worn on the left elbow or wrist of an archer either to prevent chafing from the bowstring (: 弦) twanging back to position on the release of an arrow, or to strike fear into the enemy from the sharp sound caused by the bowstring hitting the wrist guard. The 'tomo picture' () can therefore be interpre |
https://en.wikipedia.org/wiki/Cowboy%20coding | Cowboy coding is software development where programmers have autonomy over the development process. This includes control of the project's schedule, languages, algorithms, tools, frameworks and coding style. Typically, little to no coordination exists with other developers or stakeholders.
A cowboy coder can be a lone developer or part of a group of developers working with minimal process or discipline. Usually it occurs when there is little participation by business users, or fanned by management that controls only non-development aspects of the project, such as the broad targets, timelines, scope, and visuals (the "what", but not the "how").
"Cowboy coding" commonly sees usage as a derogatory term when contrasted with more structured software development methodologies.
Disadvantages
In cowboy coding, the lack of formal software project management methodologies may be indicative (though not necessarily) of a project's small size or experimental nature. Software projects with these attributes may exhibit:
Lack of release structure
Lack of estimation or implementation planning might cause a project to be delayed. Sudden deadlines or pushes to release software may encourage the use of "quick and dirty" techniques that will require further attention later.
Inexperienced developers
Cowboy coding can be common at the hobbyist or student level where developers might initially be unfamiliar with the technologies, such as testing, version control and/or build tools, usually more than just the basic coding a software project requires.
This can result in underestimating time required for learning, causing delays in the development process. Inexperience might also lead to disregard of accepted standards, making the project source difficult to read or causing conflicts between the semantics of the language constructs and the result of their output.
Uncertain design requirements
Custom software applications, even when using a proven development cycle, can experience prob |
https://en.wikipedia.org/wiki/Probabilistic%20latent%20semantic%20analysis | Probabilistic latent semantic analysis (PLSA), also known as probabilistic latent semantic indexing (PLSI, especially in information retrieval circles) is a statistical technique for the analysis of two-mode and co-occurrence data. In effect, one can derive a low-dimensional representation of the observed variables in terms of their affinity to certain hidden variables, just as in latent semantic analysis, from which PLSA evolved.
Compared to standard latent semantic analysis which stems from linear algebra and downsizes the occurrence tables (usually via a singular value decomposition), probabilistic latent semantic analysis is based on a mixture decomposition derived from a latent class model.
Model
Considering observations in the form of co-occurrences of words and documents, PLSA models the probability of each co-occurrence as a mixture of conditionally independent multinomial distributions:
with being the words' topic. Note that the number of topics is a hyperparameter that must be chosen in advance and is not estimated from the data. The first formulation is the symmetric formulation, where and are both generated from the latent class in similar ways (using the conditional probabilities and ), whereas the second formulation is the asymmetric formulation, where, for each document , a latent class is chosen conditionally to the document according to , and a word is then generated from that class according to . Although we have used words and documents in this example, the co-occurrence of any couple of discrete variables may be modelled in exactly the same way.
So, the number of parameters is equal to . The number of parameters grows linearly with the number of documents. In addition, although PLSA is a generative model of the documents in the collection it is estimated on, it is not a generative model of new documents.
Their parameters are learned using the EM algorithm.
Application
PLSA may be used in a discriminative setting, via Fisher ke |
https://en.wikipedia.org/wiki/Insteon | Insteon is a proprietary home automation (domotics) system that enables light switches, lights, thermostats, leak sensors, remote controls, motion sensors, and other electrically powered devices to interoperate through power lines, radio frequency (RF) communications, or both. It employed a dual-mesh networking topology in which all devices are peers and each device independently transmits, receives, confirm and repeats messages. Like other home automation systems, it had been associated with the Internet of things.
In mid-April of 2022, the company appeared to have abruptly shut down.
Corporate history
Insteon-based products were launched in 2005 by Smartlabs, the company which holds the trademark for Insteon. A Smartlabs subsidiary, also named Insteon, was created to market the technology. or by CEO Joe Dada. Dada had previously founded Smarthome in 1992, a home automation product catalog company, and operator of the Smarthome.com e-commerce site. In the late 1990s, Dada acquired two product engineering firms which undertook extensive product development efforts to create networking technology based on both power-line and RF communications. In 2004, the company filed for patent protection for the resultant technology, called Insteon, and it was released in 2005.
In 2012, the company released the first network-controlled light bulb using Insteon-enabled technology, and at that point Dada spun Insteon off from Smarthome.
In 2017, SmartLabs and the Insteon trademark were acquired by Richmond Capital Partners.
The company produced over 200 products featuring the technology.
As of April 15 2022, there are reports that Insteon has shut down its servers and closed. On April 16, reports emerged of users finding their Insteon Hubs offline. The company forums, web servers and API servers went offline. The company's CEO Rob Lilleness appeared to have scrubbed any references to Insteon from his LinkedIn page, and other employees also appeared to indicate on their |
https://en.wikipedia.org/wiki/Secure%20telephone | A secure telephone is a telephone that provides voice security in the form of end-to-end encryption for the telephone call, and in some cases also the mutual authentication of the call parties, protecting them against a man-in-the-middle attack. Concerns about massive growth of telephone tapping incidents led to growing demand for secure telephones.
The practical availability of secure telephones is restricted by several factors; notably politics, export issues, incompatibility between different products (the devices on each side of the call have to use the same protocol), and high (though recently decreasing) price of the devices.
Well-known products
The best-known product on the US government market is the STU-III family. However, this system has now been replaced by the Secure Terminal Equipment (STE) and SCIP standards which defines specifications for the design of equipment to secure both data and voice. The SCIP standard was developed by the NSA and the US DOD to derive more interoperability between secure communication equipment. A new family of standard secure phones has been developed based on Philip Zimmermann's VoIP encryption standard ZRTP.
VoIP and direct connection phones
As the popularity of VoIP grows, secure telephony is becoming more widely used. Many major hardware and software providers offer it as a standard feature at no extra cost.
Examples include the Gizmo5 and Twinkle. Both of the former work with offerings from the founder of PGP, Phil Zimmermann, and his VoIP secure protocol, ZRTP. ZRTP is implemented in, amongst others, Ripcord Networks product SecurePC with up to NSA Suite B compliant Elliptic Curve math libraries. ZRTP is also being made available for mobile GSM CSD as a new standard for non-VoIP secure calls.
The U.S. National Security Agency is developing a secure phone based on Google's Android called Fishbowl.
Historically significant products
Scramblers were used to secure voice traffic during World War II, but were ofte |
https://en.wikipedia.org/wiki/IMSI-catcher | An international mobile subscriber identity-catcher, or IMSI-catcher, is a telephone eavesdropping device used for intercepting mobile phone traffic and tracking location data of mobile phone users. Essentially a "fake" mobile tower acting between the target mobile phone and the service provider's real towers, it is considered a man-in-the-middle (MITM) attack. The 3G wireless standard offers some risk mitigation due to mutual authentication required from both the handset and the network. However, sophisticated attacks may be able to downgrade 3G and LTE to non-LTE network services which do not require mutual authentication.
IMSI-catchers are used in a number of countries by law enforcement and intelligence agencies, but their use has raised significant civil liberty and privacy concerns and is strictly regulated in some countries such as under the German Strafprozessordnung (StPO / Code of Criminal Procedure). Some countries do not have encrypted phone data traffic (or very weak encryption), thus rendering an IMSI-catcher unnecessary.
Overview
A virtual base transceiver station (VBTS) is a device for identifying the temporary mobile subscriber identity (TMSI), international mobile subscriber identity (IMSI) of a nearby GSM mobile phone and intercepting its calls, some are even advanced enough to detect the international mobile equipment identity (IMEI). It was patented and first commercialized by Rohde & Schwarz in 2003. The device can be viewed as simply a modified cell tower with a malicious operator, and on 4 January 2012, the Court of Appeal of England and Wales held that the patent is invalid for obviousness.
IMSI-catchers are often deployed by court order without a search warrant, the lower judicial standard of a pen register and trap-and-trace order being preferred by law enforcement. They can also be used in search and rescue operation for missing persons. Police departments have been reluctant to reveal use of these programs and contracts with vendors |
https://en.wikipedia.org/wiki/Nidogen-1 | Nidogen-1 (NID-1), formerly known as entactin, is a protein that in humans is encoded by the NID1 gene. Both nidogen-1 and nidogen-2 are essential components of the basement membrane alongside other components such as type IV collagen, proteoglycans (heparan sulfate and glycosaminoglycans), laminin and fibronectin.
Function
Nidogen-1 is a member of the nidogen family of basement membrane glycoproteins. The protein interacts with several other components of basement membranes. Structurally it (along with perlecan) connects the networks formed by collagens and laminins to each other. It may also play a role in cell interactions with the extracellular matrix.
Clinical significance
Mutations in NID1 cause autosomal dominant Dandy–Walker malformation with occipital encephalocele (ADDWOC).
Interactions
Nidogen-1 has been shown to interact with FBLN1. |
https://en.wikipedia.org/wiki/Kruskal%E2%80%93Szekeres%20coordinates | In general relativity, Kruskal–Szekeres coordinates, named after Martin Kruskal and George Szekeres, are a coordinate system for the Schwarzschild geometry for a black hole. These coordinates have the advantage that they cover the entire spacetime manifold of the maximally extended Schwarzschild solution and are well-behaved everywhere outside the physical singularity. There is no misleading coordinate singularity at the horizon.
The Kruskal–Szekeres coordinates also apply to space-time around a spherical object, but in that case do not give a description of space-time inside the radius of the object. Space-time in a region where a star is collapsing into a black hole is approximated by the Kruskal–Szekeres coordinates (or by the Schwarzschild coordinates). The surface of the star remains outside the event horizon in the Schwarzschild coordinates, but crosses it in the Kruskal–Szekeres coordinates. (In any "black hole" which we observe, we see it at a time when its matter has not yet finished collapsing, so it is not really a black hole yet.) Similarly, objects falling into a black hole remain outside the event horizon in Schwarzschild coordinates, but cross it in Kruskal–Szekeres coordinates.
Definition
Kruskal–Szekeres coordinates on a black hole geometry are defined, from the Schwarzschild coordinates , by replacing t and r by a new timelike coordinate T and a new spacelike coordinate :
for the exterior region outside the event horizon and:
for the interior region . Here is the gravitational constant multiplied by the Schwarzschild mass parameter, and this article is using units where = 1.
It follows that on the union of the exterior region, the event horizon and the interior region the Schwarzschild radial coordinate (not to be confused with the Schwarzschild radius ), is determined in terms of Kruskal–Szekeres coordinates as the (unique) solution of the equation:
Using the Lambert W function the solution is written as:
.
Moreover one sees immediately |
https://en.wikipedia.org/wiki/Telecentre | A telecentre is a public place where people can access computers, the Internet, and other digital technologies that enable them to gather information, create, learn, and communicate with others while they develop essential digital skills. Telecentres exist in almost every country, although they sometimes go by a different names including public internet access center (PIAP), village knowledge center, infocenter, Telecottage, Electronic Village Hall, community technology center (CTC), community multimedia center (CMC), multipurpose community telecentre (MCT), Common/Citizen Service Centre (CSC) and school-based telecentre. While each telecentre is different, their common focus is on the use of digital technologies to support community, economic, educational, and social development—reducing isolation, bridging the digital divide, promoting health issues, creating economic opportunities, and reaching out to youth for example.
Evolution of the telecentre movement
The telecentre movement's origins can be traced to Europe's telecottage and Electronic Village Halls (originally in Denmark) and Community Technology Centers (CTCs) in the United States, both of which emerged in the 1980s as a result of advances in computing. At a time when computers were available but not yet a common household good, public access to computers emerged as a solution. Today, although home ownership of computers is widespread in the United States and other industrialized countries, there remains a need for free public access to computing, whether it is in CTCs, telecottages or public libraries to ensure that everyone has access to technologies that have become essential.
There are also CTCs located in most of the states of Australia, they are also known as Community Resource Centres (often abbreviated to CRC) that provide technology, resources, training and educational programs to communities in regional, rural and remote areas.
Types
Beyond the differences in names, public ICT access centers |
https://en.wikipedia.org/wiki/Kernel%20density%20estimation | In statistics, kernel density estimation (KDE) is the application of kernel smoothing for probability density estimation, i.e., a non-parametric method to estimate the probability density function of a random variable based on kernels as weights. KDE answers a fundamental data smoothing problem where inferences about the population are made, based on a finite data sample. In some fields such as signal processing and econometrics it is also termed the Parzen–Rosenblatt window method, after Emanuel Parzen and Murray Rosenblatt, who are usually credited with independently creating it in its current form. One of the famous applications of kernel density estimation is in estimating the class-conditional marginal densities of data when using a naive Bayes classifier, which can improve its prediction accuracy.
Definition
Let (x1, x2, ..., xn) be independent and identically distributed samples drawn from some univariate distribution with an unknown density ƒ at any given point x. We are interested in estimating the shape of this function ƒ. Its kernel density estimator is
where K is the kernel — a non-negative function — and is a smoothing parameter called the bandwidth. A kernel with subscript h is called the scaled kernel and defined as . Intuitively one wants to choose h as small as the data will allow; however, there is always a trade-off between the bias of the estimator and its variance. The choice of bandwidth is discussed in more detail below.
A range of kernel functions are commonly used: uniform, triangular, biweight, triweight, Epanechnikov, normal, and others. The Epanechnikov kernel is optimal in a mean square error sense, though the loss of efficiency is small for the kernels listed previously. Due to its convenient mathematical properties, the normal kernel is often used, which means , where ϕ is the standard normal density function.
The construction of a kernel density estimate finds interpretations in fields outside of density estimation. For example |
https://en.wikipedia.org/wiki/Intragenomic%20conflict | Intragenomic conflict refers to the evolutionary phenomenon where genes have phenotypic effects that promote their own transmission in detriment of the transmission of other genes that reside in the same genome. The selfish gene theory postulates that natural selection will increase the frequency of those genes whose phenotypic effects cause their transmission to new organisms, and most genes achieve this by cooperating with other genes in the same genome to build an organism capable of reproducing and/or helping kin to reproduce. The assumption of the prevalence of intragenomic cooperation underlies the organism-centered concept of inclusive fitness. However, conflict among genes in the same genome may arise both in events related to reproduction (a selfish gene may "cheat" and increase its own presence in gametes or offspring above the expected according to fair Mendelian segregation and fair gametogenesis) and altruism (genes in the same genome may disagree on how to value other organisms in the context of helping kin because coefficients of relatedness diverge between genes in the same genome).
Nuclear genes
Autosomic genes usually have the same mode of transmission in sexually reproducing species due to the fairness of Mendelian segregation, but conflicts among alleles of autosomic genes may arise when an allele cheats during gametogenesis (segregation distortion) or eliminates embryos that don't contain it (lethal maternal effects). An allele may also directly convert its rival allele into a copy of itself (homing endonucleases). Finally, mobile genetic elements completely bypass Mendelian segregation, being able to insert new copies of themselves into new positions in the genome (transposons).
Segregation distortion
In principle, the two parental alleles have equal probabilities of being present in the mature gamete. However, there are several mechanisms that lead to an unequal transmission of parental alleles from parents to offspring. One example is a gen |
https://en.wikipedia.org/wiki/Auf%20Wiedersehen%20Monty | Auf Wiedersehen Monty (German for "Goodbye Monty") is a computer game for the ZX Spectrum, Commodore 64, Amstrad CPC, MSX and Commodore 16. Released in 1987, it is the fourth game in the Monty Mole series. It was written by Peter Harrap and Shaun Hollingworth with music by Rob Hubbard and Ben Daglish.
Gameplay
The player controls Monty as he travels around Europe collecting money in order to buy a Greek island - Montos, where he can safely retire. Gameplay is in the style of a flick-screen platform game, similar to many such games of the 1980s such as Technician Ted and Jet Set Willy. Some screens (such as those representing the Eiffel Tower and the Pyrenees) bear some relation to their real-life counterparts but most are just typical platform game screens.
Auf Wiedersehen Monty contains many features and peculiarities for the player to discover. Examples include being suddenly attacked by a bull's head in Spain after collecting a red cape (presumably a reference to bullfighting), a car being dropped in one of two places on entering a screen representing Düsseldorf in West Germany, a chef's hat found in Sweden (a reference to the Swedish Chef of Muppets fame; also, the two rooms representing Sweden are subtitled Bjorn and Borg), and a record in Luxembourg that when collected makes Monty breakdance to the game's title music (this may be a reference to Radio Luxembourg).
It is possible to get to areas of the game more quickly by flying from an airport using air tickets which can be collected throughout the game. Some parts of the game can only be reached in this manner.
As well as money, there are other miscellaneous objects to collect in the game for points. This was important as the player needs a certain number of points to get to Montos. These are often particular to the country Monty is visiting (such as berets in France). Bottles of wine or a glass of beer in West Germany cause Monty to briefly become drunk and his control to become slightly erratic leading |
https://en.wikipedia.org/wiki/Linear%20multistep%20method | Linear multistep methods are used for the numerical solution of ordinary differential equations. Conceptually, a numerical method starts from an initial point and then takes a short step forward in time to find the next solution point. The process continues with subsequent steps to map out the solution. Single-step methods (such as Euler's method) refer to only one previous point and its derivative to determine the current value. Methods such as Runge–Kutta take some intermediate steps (for example, a half-step) to obtain a higher order method, but then discard all previous information before taking a second step. Multistep methods attempt to gain efficiency by keeping and using the information from previous steps rather than discarding it. Consequently, multistep methods refer to several previous points and derivative values. In the case of linear multistep methods, a linear combination of the previous points and derivative values is used.
Definitions
Numerical methods for ordinary differential equations approximate solutions to initial value problems of the form
The result is approximations for the value of at discrete times :
where is the time step (sometimes referred to as ) and is an integer.
Multistep methods use information from the previous steps to calculate the next value. In particular, a linear multistep method uses a linear combination of and to calculate the value of for the desired current step. Thus, a linear multistep method is a method of the form
with . The coefficients and determine the method. The designer of the method chooses the coefficients, balancing the need to get a good approximation to the true solution against the desire to get a method that is easy to apply. Often, many coefficients are zero to simplify the method.
One can distinguish between explicit and implicit methods. If , then the method is called "explicit", since the formula can directly compute . If then the method is called "implicit", since the value of de |
https://en.wikipedia.org/wiki/Fault%20tolerance | Fault tolerance is the property that enables a system to continue operating properly in the event of the failure of one or more faults within some of its components. If its operating quality decreases at all, the decrease is proportional to the severity of the failure, as compared to a naively designed system, in which even a small failure can cause total breakdown. Fault tolerance is particularly sought after in high-availability, mission-critical, or even life-critical systems. The ability of maintaining functionality when portions of a system break down is referred to as graceful degradation.
A fault-tolerant design enables a system to continue its intended operation, possibly at a reduced level, rather than failing completely, when some part of the system fails. The term is most commonly used to describe computer systems designed to continue more or less fully operational with, perhaps, a reduction in throughput or an increase in response time in the event of some partial failure. That is, the system as a whole is not stopped due to problems either in the hardware or the software. An example in another field is a motor vehicle designed so it will continue to be drivable if one of the tires is punctured, or a structure that is able to retain its integrity in the presence of damage due to causes such as fatigue, corrosion, manufacturing flaws, or impact.
Within the scope of an individual system, fault tolerance can be achieved by anticipating exceptional conditions and building the system to cope with them, and, in general, aiming for self-stabilization so that the system converges towards an error-free state. However, if the consequences of a system failure are catastrophic, or the cost of making it sufficiently reliable is very high, a better solution may be to use some form of duplication. In any case, if the consequence of a system failure is so catastrophic, the system must be able to use reversion to fall back to a safe mode. This is similar to roll-back r |
https://en.wikipedia.org/wiki/Nucleic%20acid%20double%20helix | In molecular biology, the term double helix refers to the structure formed by double-stranded molecules of nucleic acids such as DNA. The double helical structure of a nucleic acid complex arises as a consequence of its secondary structure, and is a fundamental component in determining its tertiary structure. The term entered popular culture with the publication in 1968 of The Double Helix: A Personal Account of the Discovery of the Structure of DNA by James Watson.
The DNA double helix biopolymer of nucleic acid is held together by nucleotides which base pair together. In B-DNA, the most common double helical structure found in nature, the double helix is right-handed with about 10–10.5 base pairs per turn. The double helix structure of DNA contains a major groove and minor groove. In B-DNA the major groove is wider than the minor groove. Given the difference in widths of the major groove and minor groove, many proteins which bind to B-DNA do so through the wider major groove.
History
The double-helix model of DNA structure was first published in the journal Nature by James Watson and Francis Crick in 1953, (X,Y,Z coordinates in 1954) based on the work of Rosalind Franklin and her student Raymond Gosling, who took the crucial X-ray diffraction image of DNA labeled as "Photo 51", and Maurice Wilkins, Alexander Stokes, and Herbert Wilson, and base-pairing chemical and biochemical information by Erwin Chargaff. Before this, Linus Pauling—who had already accurately characterised the conformation of protein secondary structure motifs—and his collaborator Robert Corey had posited, erroneously, that DNA would adopt a triple-stranded conformation.
The realization that the structure of DNA is that of a double-helix elucidated the mechanism of base pairing by which genetic information is stored and copied in living organisms and is widely considered one of the most important scientific discoveries of the 20th century. Crick, Wilkins, and Watson each received one-third |
https://en.wikipedia.org/wiki/Volterra%20integral%20equation | In mathematics, the Volterra integral equations are a special type of integral equations. They are divided into two groups referred to as the first and the second kind.
A linear Volterra equation of the first kind is
where f is a given function and x is an unknown function to be solved for. A linear Volterra equation of the second kind is
In operator theory, and in Fredholm theory, the corresponding operators are called Volterra operators. A useful method to solve such equations, the Adomian decomposition method, is due to George Adomian.
A linear Volterra integral equation is a convolution equation if
The function in the integral is called the kernel. Such equations can be analyzed and solved by means of Laplace transform techniques.
For a weakly singular kernel of the form with , Volterra integral equation of the first kind can conveniently be transformed into a classical Abel integral equation.
The Volterra integral equations were introduced by Vito Volterra and then studied by Traian Lalescu in his 1908 thesis, Sur les équations de Volterra, written under the direction of Émile Picard. In 1911, Lalescu wrote the first book ever on integral equations.
Volterra integral equations find application in demography as Lotka's integral equation, the study of viscoelastic materials,
in actuarial science through the renewal equation, and in fluid mechanics to describe the flow behavior near finite-sized boundaries.
Conversion of Volterra equation of the first kind to the second kind
A linear Volterra equation of the first kind can always be reduced to a linear Volterra equation of the second kind, assuming that . Taking the derivative of the first kind Volterra equation gives us:Dividing through by yields:Defining and completes the transformation of the first kind equation into a linear Volterra equation of the second kind.
Numerical solution using trapezoidal rule
A standard method for computing the numerical solution of a linear Volterra equation |
https://en.wikipedia.org/wiki/Schering%20AG | Schering AG was a research-centered German multinational pharmaceutical company headquartered in Wedding, Berlin, which operated as an independent company from 1851 to 2006. In 2006, it was bought by Bayer AG and merged to form the Bayer subsidiary Bayer Schering Pharma AG, which was renamed Bayer HealthCare Pharmaceuticals in 2011. Schering was listed on the Frankfurt Stock Exchange and had 26,000 employees as of 2004.
The American pharmaceutical company Schering-Plough, formerly the Schering Corporation, was originally the US subsidiary of Schering AG, and merged with Merck & Co. in 2009.
History
In 1851, Ernst Christian Friedrich Schering opened the Grüne Apotheke (Green Pharmacy) in Berlin's Chausseestraße, and in 1871, converted into the name Chemische Fabrik auf Actien (formerly E. Schering). This date is the company's date of incorporation.
The company grew strongly in the following years. In 1913, the company employed 935 workers, 112 master craftsman and 180 office employees. In addition to the Berlin site, two factories were also located in Russia (Moscow and Wydriza (Idritsa)) with over 1,000 workers and a plant in Great Britain. Turnover at the time was about 10 million German gold mark, created with the production of photochemicals and pharmaceuticals. Important products produced were salicylic acid, the antigout preparation atophan, various sleeping and disinfecting agents.
At the beginning of the 1920s, Schering took over the wash and colouring company located in the Berlin district Köpenick. In 1922, the management acquired the majority of shares in the chemical factory Chemischen Fabrik auf Actien (formerly E. Schering) from the Upper Silesian . By 1929, Schering had built a new production site in Berlin-Grünau, Cöpenicker Strasse, on a former storage area of the Kahlbaum chemical factory.
In 1937, the companies Kokswerke und Chemische Fabriken AG and the Chemischen Fabrik auf Actien amalgamated with the sister company Schering-Kahlbaum AG and |
https://en.wikipedia.org/wiki/Fresenius%20%28company%29 | Fresenius SE & Co. KGaA is a European multinational health care company based in Bad Homburg vor der Höhe, Germany. It provides products and services for dialysis in hospitals, as well as inpatient and outpatient medical care. The company is involved in hospital management and in engineering and services for medical centers and other health care facilities.
The company is ranked 411th in the Forbes Global 2000 list in 2023.
In March 2022, it announced plans to merge with InterWell Health and Cricket Health to form a new company, which will operate under the InterWell Health brand, focused on services for the earlier stages of kidney disease.
Operations
There are four divisions:
Fresenius Medical Care, a publicly traded company of which Fresenius owns 30.8%, focuses on patients with chronic kidney failure. With its North American headquarters in Waltham, Massachusetts, it holds a 38% market share in the dialysis market in the United States.
Fresenius Helios is the largest hospital operator and provider of inpatient and outpatient in Germany. The Helios Kliniken has more than 110 hospitals and more than 30,000 beds, treating over 4 million patients annually.
Fresenius Kabi is a supplier of essential drugs, clinical nutrition products, and medical devices. It produces generic versions of intravenous oncology products such as Paclitaxel, Irinotecan, Oxaliplatin, Gemcitabine, Cytarabine, Carboplatin, Topotecan, Docetaxel, and Epirubicin.
Fresenius Vamed develops and manages health care facilities.
Structure
Fresenius SE & Co. KGaA
Fresenius Medical Care
NxStage Medical, Inc.
Fresenius Helios
Helios Kliniken GmbH
Humaine Kliniken
IDC Salud Holding S.L.U. (Quirónsalud)
Damp Group
Fresenius Kabi AG
Labesfal SA
Fresenius Kabi Oncology Plc
Dabur Pharma Ltd
APP Pharmaceuticals, Inc
Fenwal Holdings, Inc.
Fresenius Vamed
Calea UK
History
The company was founded by Eduard Fresenius in 1912.
In 1946, Fresenius died. Else Kröner, his foster-daughter and |
https://en.wikipedia.org/wiki/Germania%20%28personification%29 | Germania (; ) is the personification of the German nation or the Germans as a whole. Like many other national personification symbols, she appeared first during the Roman Era. During the Medieval era, she was usually portrayed as one of the lands or provinces ruled by the emperors of the Holy Roman Empire, and not as the most prominent but in a subordinate position to imperial power and other provinces. Around 1500, together with the birth of the Holy Roman Empire of the German Nation, Emperor Maximilian I and his humanists reinvented her as Mother of the Nation.
She is also commonly associated with the Romantic Era and the Revolutions of 1848, though the figure was later used by Imperial Germany.
Description
"Germania" is the Latin name of the country called "Deutschland" in the spoken language of its own inhabitants, though used as the country's name in various other languages, such as "Germany" in English. In the country itself, the use of the Latin "Germania" was mainly literary and poetical, linked with patriotic and nationalist feelings, like "Helvetia" for Switzerland, "Hibernia" for Ireland, "Caledonia" for Scotland, "Lusitania" for Portugal etc.
Germania as personification is usually depicted as a robust woman with long, flowing, reddish-blonde hair and wearing armour. She often wields the Reichsschwert (imperial sword), and possesses a medieval-style shield that sometimes bears the image of a black eagle on a gold field. Additionally, she is sometimes shown as carrying or wearing the Imperial Crown of the Holy Roman Empire.
In post-1918 images, the banner she holds is the black-red-gold flag of modern Germany, but in depictions from 1871 to 1918 it is the black-white-red flag of the German Empire.
Meanings of some symbols
History
Roman era
The figure of Germania appeared in Roman times, usually on coins, at first as a captive Amazon subdued by the Romans. Sometimes, however, she appeared in a more dignified form as manifestation of a more integ |
https://en.wikipedia.org/wiki/Dym%20equation | In mathematics, and in particular in the theory of solitons, the Dym equation (HD) is the third-order partial differential equation
It is often written in the equivalent form for some function v of one space variable and time
The Dym equation first appeared in Kruskal and is attributed to an unpublished paper by Harry Dym.
The Dym equation represents a system in which dispersion and nonlinearity are coupled together. HD is a completely integrable nonlinear evolution equation that may be solved by means of the inverse scattering transform. It obeys an infinite number of conservation laws; it does not possess the Painlevé property.
The Dym equation has strong links to the Korteweg–de Vries equation. C.S. Gardner, J.M. Greene, Kruskal and R.M. Miura applied [Dym equation] to the solution of corresponding problem in Korteweg–de Vries equation. The Lax pair of the Harry Dym equation is associated with the Sturm–Liouville operator.
The Liouville transformation transforms this operator isospectrally into the Schrödinger operator.
Thus by the inverse Liouville transformation solutions of the Korteweg–de Vries equation are transformed
into solutions of the Dym equation. An explicit solution of the Dym equation, valid in a finite interval, is found by an auto-Bäcklund transform
Notes |
https://en.wikipedia.org/wiki/COQ7 | Mitochondrial 5-demethoxyubiquinone hydroxylase (DMQ hydroxylase), also known as coenzyme Q7, hydroxylase, is an enzyme that in humans is encoded by the COQ7 gene. The clk-1 (clock-1) gene encodes this protein that is necessary for ubiquinone biosynthesis in the worm Caenorhabditis elegans and other eukaryotes. The mouse version of the gene is called mclk-1 and the human, fruit fly and yeast homolog COQ7 (coenzyme Q biosynthesis protein 7).
CLK-1 is not to be confused with the unrelated human protein CLK1 which plays a role in RNA splicing.
Structure
The protein has two repeats of approximately 90 amino acids, that contain two conserved motifs predicted to be important for coordination of iron. The structure and function of the gene are highly conserved among different species.
The C. elegans protein contains 187 amino acid residues (20 kilodaltons), the human homolog 217 amino acid residues (24 kilodaltons, gene consisting of six exons spanning 11 kb and located on chromosome 16).
Mitochondrial function
Ubiquinone is a small redox active lipid that is found in most cellular membranes where it acts as a cofactor in numerous cellular redox processes, including mitochondrial electron transport. As a cofactor, ubiquinone is often involved in processes that produce reactive oxygen species (ROS). In addition, ubiquinone is one of the main endogenous antioxidants of the cell. The CLK-1 enzyme is responsible for the hydroxylation of 5-demethoxyubiquinone to 5-hydroxyubiquinone.
It has been shown that mutations in the gene are associated with increased lifespan. Defects of the gene slow down a variety of developmental and physiological processes, including the cell cycle, embryogenesis, post-embryonic growth, rhythmic behaviors and aging.
Nuclear function
CLK-1 and COQ7 predominantly localise to mitochondria to participate in the ubiquinone biosynthetic pathway which is found there. However, a small pool of CLK-1 and COQ7 translocates to the nucleus in response |
https://en.wikipedia.org/wiki/Comb%20drive | Comb-drives are microelectromechanical actuators, often used as linear actuators, which utilize electrostatic forces that act between two electrically conductive combs. Comb drive actuators typically operate at the micro- or nanometer scale and are generally manufactured by bulk micromachining or surface micromachining a silicon wafer substrate.
The attractive electrostatic forces are created when a voltage is applied between the static and moving combs causing them to be drawn together. The force developed by the actuator is proportional to the change in capacitance between the two combs, increasing with driving voltage, the number of comb teeth, and the gap between the teeth. The combs are arranged so that they never touch (because then there would be no voltage difference). Typically the teeth are arranged so that they can slide past one another until each tooth occupies the slot in the opposite comb.
Restoring springs, levers, and crankshafts can be added if the motor's linear operation is to be converted to rotation or other motions.
The force can be derived by first starting with the energy stored in a capacitor and then differentiating in the direction of the force. The energy in a capacitor is given by:
Using the capacitance for a parallel plate capacitor, the force is:
= applied electric potential,
= relative permittivity of dielectric,
= permittivity of free space (8.85 pF/m),
= total number of fingers on both sides of electrodes,
= thickness in the out-of-plane direction of the electrodes,
= gap between electrodes.
Structure of Comb-drives
• rows of interlocking teeth
• half fixed
• half part of movable assembly
• electrically isolated
• electrostatic attraction/repulsion
– CMOS drive voltage
• many teeth increased force
– typically 10μm long and strong
Scaling Issues
Comb drives cannot scale to large gap distances (equivalently actuation distance), since development of effective forces at large gaps distances would requir |
https://en.wikipedia.org/wiki/Civil%20defense%20Geiger%20counters | Geiger counter is a colloquial name for any hand-held radiation measuring device in civil defense, but most civil defense devices were ion-chamber radiological survey meters capable of measuring only high levels of radiation that would be present after a major nuclear event.
Most Geiger and ion-chamber survey meters were issued by governmental civil defense organizations in several countries from the 1950s in the midst of the Cold War in an effort to help prepare citizens for a nuclear attack.
Many of these same instruments are still in use today by some states, Texas amongst them, under the jurisdiction of the Texas Bureau of Radiation Control. They are regularly maintained, calibrated and deployed to fire departments and other emergency services.
US models
CD Counters came in a variety of different models, each with specific capabilities. Each of these models has an analog meter from 1 to 5, with 1/10 tick marks. Thus, at X10, the meter reads from 1 to 50.
CD meters were produced by a number of different firms under contract. Victoreen, Lionel, Electro Neutronics, Nuclear Measurements, Chatham Electronics, International Pump and Machine Works, Universal Atomics, Anton Electronic Laboratories; Landers, Frary, & Clark; El Tronics, Jordan, and Nuclear Chicago are among the many manufacturers contracted.
Regardless of producer, most counters exhibit the same basic physical characteristics, albeit with slight variations between some production runs: a yellow case with black knobs and meter bezels. Most US meters had a "CD" sticker on the side of the case.
True Geiger counters
These are instruments which use the Geiger principle of detection.
Type CD V-700
The CD V-700 is a Geiger counter employing a probe equipped with a Geiger–Müller tube manufactured by several companies under contract to US federal civil defense agencies in the 1950s and 1960s. This unit is quite sensitive and can be used to measure low levels of gamma radiation and detect beta radiation. |
https://en.wikipedia.org/wiki/Megahertz%20myth | The megahertz myth, or in more recent cases the gigahertz myth, refers to the misconception of only using clock rate (for example measured in megahertz or gigahertz) to compare the performance of different microprocessors. While clock rates are a valid way of comparing the performance of different speeds of the same model and type of processor, other factors such as an amount of execution units, pipeline depth, cache hierarchy, branch prediction, and instruction sets can greatly affect the performance when considering different processors. For example, one processor may take two clock cycles to add two numbers and another clock cycle to multiply by a third number, whereas another processor may do the same calculation in two clock cycles. Comparisons between different types of processors are difficult because performance varies depending on the type of task. A benchmark is a more thorough way of measuring and comparing computer performance.
The myth started around 1984 when comparing the Apple II with the IBM PC. The argument was that the IBM computer was five times faster than the Apple II, as its Intel 8088 processor had a clock speed roughly 4.7 times the clock speed of the MOS Technology 6502 used in the latter. However, what really matters is not how finely divided a machine's instructions are, but how long it takes to complete a given task. Consider the LDA # (Load Accumulator Immediate) instruction. On a 6502 that instruction requires two clock cycles, or 2 μs at 1 MHz. Although the 4.77 MHz 8088's clock cycles are shorter, the LDA # needs at least 4 of them, so it takes 4 / 4.77 MHz = 0.84 μs at least. So, at best, that instruction runs only a little more than 2 times as fast on the original IBM PC than on the Apple II.
History
Background
The x86 CISC based CPU architecture which Intel introduced in 1978 was used as the standard for the DOS based IBM PC, and developments of it still continue to dominate the Microsoft Windows market. An IBM RISC based arch |
https://en.wikipedia.org/wiki/Business%20activity%20monitoring | Business activity monitoring (BAM) is software that aids the monitoring of business activities that are implemented in computer systems.
The term was originally coined by analysts at Gartner, Inc. and refers to the aggregation, analysis, and presentation of real-time information about activities inside organizations, customers, and partners. A business activity can either be a business process that is orchestrated by a business process management (BPM) software, or a series of activities spanning across multiple systems and applications. BAM is intended to provide a summary of business activities to operations managers and upper management.
Description
Business activity monitoring provides real-time information about the status and results of various operations, processes, and transactions. The main benefits of BAM are to enable an enterprise to make better informed business decisions, quickly address problem areas, and re-position organizations to take full advantage of emerging opportunities.
One of the most visible features of BAM is the presentation of information on dashboards containing the key performance indicators (KPIs) used to provide assurance and visibility of activity and performance. This information is used by technical and business operations to provide visibility, measurement, and assurance of key business activities. It can also be exploited by event correlation to detect and warn against impending problems.
Although BAM systems usually use a computer dashboard display to present data, BAM is distinct from the dashboards used by business intelligence (BI) insofar as events are processed in real-time or near real-time and pushed to the dashboard in BAM systems, whereas BI dashboards refresh at predetermined intervals by polling or querying databases. Depending on the refresh interval selected, BAM and BI dashboards can be similar or vary considerably.
Some products provide trouble notification functions, which allows them to interact automatic |
https://en.wikipedia.org/wiki/Sparklies | Sparklies is a form of interference on analogue satellite television transmissions.
Sparklies are black or white 'hard' interference dots (as opposed to the 'soft' interference patterns of terrestrial television), caused either by too weak or too strong a signal. When within the satellite's rated reception footprint, sparklies are most likely to be caused by a misaligned dish, or LNBs which are too high- or too low-gain for the dish and receiver.
The term "sparklies" is used by British Sky Broadcasting (BSkyB) and a number of hardware makers including Amstrad and Pace.
Sparklies do not occur on digital satellite systems; similar problems with digital signals cause MPEG artifacts.
See also
Salt and pepper noise |
https://en.wikipedia.org/wiki/Radical%20axis | In Euclidean geometry, the radical axis of two non-concentric circles is the set of points whose power with respect to the circles are equal. For this reason the radical axis is also called the power line or power bisector of the two circles. In detail:
For two circles with centers and radii the powers of a point with respect to the circles are
Point belongs to the radical axis, if
If the circles have two points in common, the radical axis is the common secant line of the circles.
If point is outside the circles, has equal tangential distance to both the circles.
If the radii are equal, the radical axis is the line segment bisector of .
In any case the radical axis is a line perpendicular to
On notations
The notation radical axis was used by the French mathematician M. Chasles as axe radical.
J.V. Poncelet used .
J. Plücker introduced the term .
J. Steiner called the radical axis line of equal powers () which led to power line ().
Properties
Geometric shape and its position
Let be the position vectors of the points . Then the defining equation of the radical line can be written as:
From the right equation one gets
The pointset of the radical axis is indeed a line and is perpendicular to the line through the circle centers.
( is a normal vector to the radical axis !)
Dividing the equation by , one gets the Hessian normal form. Inserting the position vectors of the centers yields the distances of the centers to the radical axis:
,
with .
( may be negative if is not between .)
If the circles are intersecting at two points, the radical line runs through the common points. If they only touch each other, the radical line is the common tangent line.
Special positions
The radical axis of two intersecting circles is their common secant line.
The radical axis of two touching circles is their common tangent.
The radical axis of two non intersecting circles is the common secant of two convenient equipower circles (see below).
Orthogonal circles
|
https://en.wikipedia.org/wiki/Fortinet | Fortinet is a cybersecurity company with headquarters in Sunnyvale, California. The company develops and sells security solutions like firewalls, endpoint security and intrusion detection systems. Fortinet has offices located all over the world.
Brothers Ken Xie and Michael Xie founded Fortinet in 2000. The company's first and main product was FortiGate, a physical firewall. The company later added wireless access points, sandbox and messaging security. The company went public in November 2009.
History
Early history
In 2000, Ken Xie and his brother Michael Xie co-founded Appligation Inc. The company was renamed ApSecure in December 2000 and later renamed again to Fortinet, based on the phrase "Fortified Networks."
Fortinet introduced its first product, FortiGate, in 2002, followed by anti-spam and anti-virus software. The company raised $13 million in private funding from 2000 to early 2003. Fortinet's first channel program was established in October 2003. The company began distributing its products in Canada in December 2003 and in the UK in February 2004. By 2004, Fortinet had offices in Asia, Europe, and North America.
In April 2005, a German court issued a preliminary injunction against Fortinet's UK subsidiary in relation to source code for its GPL-licensed elements. The dispute ended a month later after Fortinet agreed to make the source code available upon request.
Growth and expansion
Fortinet became profitable in the third quarter of 2008. Later that year, the company acquired the intellectual property of IPLocks, a database security and auditing company. In August 2009, Fortinet acquired the intellectual property and other assets of Woven Systems, an Ethernet switching company.
According to market research firm IDC, by November 2009, Fortinet held over 15 percent of the unified threat management market. Also in 2009, CRN Magazines survey-based annual report card placed Fortinet first in network security hardware, up from seventh in 2007. In November |
https://en.wikipedia.org/wiki/Power%20of%20a%20point | In elementary plane geometry, the power of a point is a real number that reflects the relative distance of a given point from a given circle. It was introduced by Jakob Steiner in 1826.
Specifically, the power of a point with respect to a circle with center and radius is defined by
If is outside the circle, then ,
if is on the circle, then and
if is inside the circle, then .
Due to the Pythagorean theorem the number has the simple geometric meanings shown in the diagram: For a point outside the circle is the squared tangential distance of point to the circle .
Points with equal power, isolines of , are circles concentric to circle .
Steiner used the power of a point for proofs of several statements on circles, for example:
Determination of a circle, that intersects four circles by the same angle.
Solving the Problem of Apollonius
Construction of the Malfatti circles: For a given triangle determine three circles, which touch each other and two sides of the triangle each.
Spherical version of Malfatti's problem: The triangle is a spherical one.
Essential tools for investigations on circles are the radical axis of two circles and the radical center of three circles.
The power diagram of a set of circles divides the plane into regions within which the circle minimizing the power is constant.
More generally, French mathematician Edmond Laguerre defined the power of a point with respect to any algebraic curve in a similar way.
Geometric properties
Besides the properties mentioned in the lead there are further properties:
Orthogonal circle
For any point outside of the circle there are two tangent points on circle , which have equal distance to . Hence the circle with center through passes , too, and intersects orthogonal:
The circle with center and radius intersects circle orthogonal.
If the radius of the circle centered at is different from one gets the angle of intersection between the two circles applying the Law of c |
https://en.wikipedia.org/wiki/Xinu | Xinu Is Not Unix (Xinu, a recursive acronym), is an operating system for embedded systems, originally developed by Douglas Comer for educational use at Purdue University in the 1980s. The name is both recursive, and is Unix spelled backwards. It has been ported to many hardware platforms, including the DEC PDP-11 and VAX systems, Motorola 68k (Sun-2 and Sun-3 workstations, AT&T UNIX PC, MECB), Intel x86, PowerPC G3, MIPS, ARM architecture and AVR (atmega328p/Arduino). Xinu was also used for some models of Lexmark printers.
Despite its name suggesting some similarity to Unix, Xinu is a different type of operating system, written with no knowledge of the Unix source code, or compatibility goals. It uses different abstractions, and system calls, some with names matching those of Unix, but different semantics.
History
Xinu first ran on the LSI-11 platform. A Motorola 68000 port was done by Derrick Burns in 1984. A VAX port was done in 1986 by Comer and Tom Stonecypher, an IBM PC compatible port in 1988 by Comer and Timothy Fossum, a second Motorola 68000 (Sun 3) port circa 1988 by Shawn Ostermann and Steve Chapin, a Macintosh platform port in 1989 by Comer and Steven Munson, an Intel 80486 version by John Lin in 1995, a SPARC port by Jim Griffioen, and a PowerPC port in 2005 and MIPS port of Embedded Xinu in 2006 by Dennis Brylow.
Later developments
Dennis Brylow at Marquette University has ported Xinu to both the PowerPC and MIPSEL processor architectures. Porting Xinu to reduced instruction set computing (RISC) architectures greatly simplified its implementation, increasing its ability to be used as a tool for teaching and research.
MIPSEL was chosen as a target architecture due to the proliferation of the MIPSEL-based WRT54GL router and the cool incentive that motivates some students to become involved in projects. The first embedded Xinu systems laboratory based on the WRT54GL router was developed at Marquette University. In collaboration with the Marquette Xinu |
https://en.wikipedia.org/wiki/Cluster%20decay | Cluster decay, also named heavy particle radioactivity, heavy ion radioactivity or heavy cluster decay, is a rare type of nuclear decay in which an atomic nucleus emits a small "cluster" of neutrons and protons, more than in an alpha particle, but less than a typical binary fission fragment. Ternary fission into three fragments also produces products in the cluster size. The loss of protons from the parent nucleus changes it to the nucleus of a different element, the daughter, with a mass number Ad = A − Ae and atomic number Zd = Z − Ze, where Ae = Ne + Ze.
For example:
→ +
This type of rare decay mode was observed in radioisotopes that decay predominantly by alpha emission, and it occurs only in a small percentage of the decays for all such isotopes.
The branching ratio with respect to alpha decay is rather small (see the Table below).
Ta and Tc are the half-lives of the parent nucleus relative to alpha decay and cluster radioactivity, respectively.
Cluster decay, like alpha decay, is a quantum tunneling process: in order to be emitted, the cluster must penetrate a potential barrier. This is a different process than the more random nuclear disintegration that precedes light fragment emission in ternary fission, which may be a result of a nuclear reaction, but can also be a type of spontaneous radioactive decay in certain nuclides, demonstrating that input energy is not necessarily needed for fission, which remains a fundamentally different process mechanistically.
Theoretically, any nucleus with Z > 40 for which the released energy (Q value) is a positive quantity, can be a cluster-emitter. In practice, observations are severely restricted to limitations imposed by currently available experimental techniques which require a sufficiently short half-life, Tc < 1032 s, and a sufficiently large branching ratio B > 10−17.
In the absence of any energy loss for fragment deformation and excitation, as in cold fission phenomena or in alpha decay, the total kinetic e |
https://en.wikipedia.org/wiki/Abel%20polynomials | The Abel polynomials are a sequence of polynomials named after Niels Henrik Abel, defined by the following equation:
This polynomial sequence is of binomial type: conversely, every polynomial sequence of binomial type may be obtained from the Abel sequence using umbral calculus.
Examples
For , the polynomials are
For , the polynomials are |
https://en.wikipedia.org/wiki/European%20Vegetarian%20Union | The European Vegetarian Union (EVU) is a non-profit, non-governmental umbrella organisation for vegan and vegetarian societies and groups in Europe. The union works in the areas of vegetarianism, nutrition, health, consumer protection, climate and environment, and food labelling.
History
The EVU distributed the 1995 film Devour the Earth about the global consequences of meat consumption. The film was produced by the Vegetarian Society, written by Tony Wardle and narrated by Paul McCartney.
In October 2011, Renato Pichler, Board Member of the EVU, reported that the French government's Décret 2011-1227 and associated (September 30, 2011) effectively outlaws the serving of vegan meals at any public or private school in France. Similar decrees are proposed for kindergartens, hospitals, prisons and retirement homes.
Purpose
The main activities of the EVU are:
To support and represent member societies on a European level, and to offer a platform for close cooperation;
To raise public awareness of, and promote vegetarianism, vegetarian/plant-based issues and the benefits of a vegetarian/plant-based lifestyle;
To lobby governments, European institutions and organisations for greater recognition of plant-based issues in policy decisions; and
To promote transparent food labelling in the interest of all vegetarian and vegan consumers across Europe and the rest of the world.
Labelling
V-Label
EVU has acted as the background organisation for the V-Label in the past. Some of EVU's member organisations certify products with the label. The label was launched in 1995 and redesigned in 2023 to better differentiate between the vegan and the vegetarian label.
Other labels in the European Union
The European Vegetarian Union has tried to legally define the use of the labels "vegetarian" and "vegan" on food items. They have argued that the vegan label on a product should have a clear and standard meaning. They have put forth two main requirements:
"The deliberate use |
https://en.wikipedia.org/wiki/Rice%20bran%20oil | Rice bran oil is the oil extracted from the hard outer brown layer of rice called bran. It is known for its high smoke point of and mild flavor, making it suitable for high-temperature cooking methods such as stir frying and deep frying. It is popular as a cooking oil in East Asia, the Indian subcontinent, and Southeast Asia including India, Nepal, Bangladesh, Indonesia, Japan, Southern China and Malaysia.
Composition and properties
Rice bran oil has a composition similar to that of peanut oil, with 38% monounsaturated, 37% polyunsaturated, and 25% saturated fatty acids.
A component of rice bran oil is the γ-oryzanol, at around 2% of crude oil content. Thought to be a single compound when initially isolated, γ-oryzanol is now known to be a mixture of steryl and other triterpenyl esters of ferulic acids. Also present are tocopherols and tocotrienols (two types of vitamin E) and phytosterols.
Fatty acid composition
Physical properties of crude and refined rice bran oil
Research
Rice bran oil consumption has been found to significantly decrease total cholesterol (TC), LDL-C and triglyceride (TG) levels.
Uses
Rice bran oil is an edible oil which is used in various forms of food preparation. It is also the basis of some vegetable ghee. Rice bran wax, obtained from rice bran oil, is used as a substitute for carnauba wax in cosmetics, confectionery, shoe creams, and polishing compounds.
Isolated γ-oryzanol from rice bran oil is available in China as an over-the-counter drug, and in other countries as a dietary supplement. There is no meaningful evidence supporting its efficacy for treating any medical condition.
Comparison to other vegetable oils
See also
Cereal germ
Bran
Rice germ oil
Wheat germ oil
Wheat bran oil
Yushō disease |
https://en.wikipedia.org/wiki/Wastebasket%20taxon | Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the purpose of classifying organisms that do not fit anywhere else. They are typically defined by either their designated members' often superficial similarity to each other, or their lack of one or more distinct character states or by their not belonging to one or more other taxa. Wastebasket taxa are by definition either paraphyletic or polyphyletic, and are therefore not considered valid taxa under strict cladistic rules of taxonomy. The name of a wastebasket taxon may in some cases be retained as the designation of an evolutionary grade, however.
The term was coined in a 1985 essay by Steven Jay Gould.
Examples
There are many examples of paraphyletic groups, but true "wastebasket" taxa are those that are known not to, and perhaps not intended to, represent natural groups, but are nevertheless used as convenient groups of organisms. The acritarchs are perhaps the most famous example. Wastebasket taxa are often old (and perhaps not described with the systematic rigour and precision that is possible in the light of accumulated knowledge of diversity) and populous; further characteristics are reviewed by.
The Flacourtiaceae, a now-defunct family of flowering plants – the Angiosperm Phylogeny Group has placed its tribes and genera in various other families, especially the Achariaceae and Salicaceae.
The obsolete kingdom Protista is composed of all eukaryotes that are not animals, plants or fungi, leaving to the protists all single-celled eukaryotes.
The Tricholomataceae is a fungal group, at one point composed of the white-, yellow-, or pink-spored genera in the Agaricales not already classified as belonging to the Amanitaceae, Lepiotaceae, Hygrophoraceae, Pluteaceae, or Entolomataceae.
Carnosauria and Thecodontia are fossil groups, banded together back when the limited fossil record did not allow for a more deta |
https://en.wikipedia.org/wiki/Oligodynamic%20effect | The oligodynamic effect (from Greek oligos, "few", and dynamis, "force") is a biocidal effect of metals, especially heavy metals, that occurs even in low concentrations.
In modern times, the effect was observed by Carl Nägeli, although he did not identify the cause. Brass doorknobs and silverware both exhibit this effect to an extent.
Mechanism
The metals react with thiol (-SH) or amine (-NH(1,2,3)) groups of proteins, a mode of action to which microorganisms may develop resistance. Such resistance may be transmitted by plasmids.
List of uses
Aluminium
Aluminium triacetate (Burow's solution) is used as an astringent mild antiseptic.
Antimony
Orthoesters of diarylstibinic acids are fungicides and bactericides, used in paints, plastics, and fibers. Trivalent organic antimony was used in therapy for schistosomiasis.
Arsenic
For many decades, arsenic was used medicinally to treat syphilis. It is still used in sheep dips, rat poisons, wood preservatives, weed killers, and other pesticides. Arsenic is poisonous if it enters the human body.
Barium
Barium polysulfide is a fungicide and acaricide used in fruit and grape growing.
Bismuth
Bismuth compounds have been used because of their astringent, antiphlogistic, bacteriostatic, and disinfecting actions. In dermatology bismuth subgallate is still used in vulnerary salves and powders as well as in antimycotics. In the past, bismuth has also been used to treat syphilis and malaria.
Boron
Boric acid esters derived from glycols (example, organo-borate formulation, Biobor JF) are being used for the control of microorganisms in fuel systems containing water.
Copper
Brass vessels release a small amount of copper ions into stored water, thus killing fecal bacterial counts as high as 1 million bacteria per milliliter.
Copper sulfate mixed with lime (Bordeaux mixture) is used as a fungicide and antihelminthic. Copper sulfate is used chiefly to destroy green algae (algicide) that grow in reservoirs, stock ponds, swi |
https://en.wikipedia.org/wiki/Trapped-ion%20quantum%20computer | A trapped-ion quantum computer is one proposed approach to a large-scale quantum computer. Ions, or charged atomic particles, can be confined and suspended in free space using electromagnetic fields. Qubits are stored in stable electronic states of each ion, and quantum information can be transferred through the collective quantized motion of the ions in a shared trap (interacting through the Coulomb force). Lasers are applied to induce coupling between the qubit states (for single qubit operations) or coupling between the internal qubit states and the external motional states (for entanglement between qubits).
The fundamental operations of a quantum computer have been demonstrated experimentally with the currently highest accuracy in trapped-ion systems. Promising schemes in development to scale the system to arbitrarily large numbers of qubits include transporting ions to spatially distinct locations in an array of ion traps, building large entangled states via photonically connected networks of remotely entangled ion chains, and combinations of these two ideas. This makes the trapped-ion quantum computer system one of the most promising architectures for a scalable, universal quantum computer. As of April 2018, the largest number of particles to be controllably entangled is 20 trapped ions.
History
The first implementation scheme for a controlled-NOT quantum gate was proposed by Ignacio Cirac and Peter Zoller in 1995, specifically for the trapped-ion system. The same year, a key step in the controlled-NOT gate was experimentally realized at NIST Ion Storage Group, and research in quantum computing began to take off worldwide.
In 2021, researchers from the University of Innsbruck presented a quantum computing demonstrator that fits inside two 19-inch server racks, the world's first quality standards-meeting compact trapped-ion quantum computer.
Paul trap
The electrodynamic quadrupole ion trap currently used in trapped-ion quantum computing research was in |
https://en.wikipedia.org/wiki/Yves%20Meyer | Yves F. Meyer (; born 19 July 1939) is a French mathematician. He is among the progenitors of wavelet theory, having proposed the Meyer wavelet. Meyer was awarded the Abel Prize in 2017.
Biography
Born in Paris in a Jewish family, Yves Meyer studied at the Lycée Carnot in Tunis; he won the French General Student Competition (Concours Général) in Mathematics, and was placed first in the entrance examination for the École Normale Supérieure in 1957. He obtained his Ph.D. in 1966, under the supervision of Jean-Pierre Kahane. The Mexican historian Jean Meyer is his cousin.
Yves Meyer taught at the Prytanée national militaire during his military service (1960–1963), then was a teaching assistant at the Université de Strasbourg (1963–1966), a professor at Université Paris-Sud (1966–1980), a professor at École Polytechnique (1980–1986), a professor at Université Paris-Dauphine (1985–1995), a senior researcher at the Centre national de la recherche scientifique (CNRS) (1995–1999), an invited professor at the Conservatoire National des Arts et Métiers (2000), a professor at École Normale Supérieure de Cachan (1999–2003), and has been a professor emeritus at Ecole Normale Supérieure de Cachan since 2004.
He was awarded the 2010 Gauss Prize for fundamental contributions to number theory, operator theory and harmonic analysis, and his pivotal role in the development of wavelets and multiresolution analysis. He also received the 2017 Abel Prize "for his pivotal role in the development of the mathematical theory of wavelets."
Publications
Awards and recognitions
He is a member of the Académie des Sciences since 1993.
Meyer was an Invited Speaker at the ICM in 1970 in Nice, in 1983 in Warsaw, and in 1990 in Kyoto.
In 2010, Yves Meyer was awarded the Carl Friedrich Gauss Prize.
In 2012 he became a fellow of the American Mathematical Society.
In 2017 he was awarded the Abel Prize for his pivotal role in developing the mathematical theory of wavelets.
In 2020 he receive |
https://en.wikipedia.org/wiki/MIL-STD-498 | MIL-STD-498, Military Standard Software Development and Documentation, was a United States military standard whose purpose was to "establish uniform requirements for software development and documentation." It was released Nov. 8, 1994, and replaced DOD-STD-2167A, DOD-STD-2168, DOD-STD-7935A, and DOD-STD-1703. It was meant as an interim standard, to be in effect for about two years until a commercial standard was developed.
Unlike previous efforts like the seminal DOD-STD-2167A which was mainly focused on the risky new area of software development, MIL-STD-498 was the first attempt at comprehensive description of the systems development life-cycle. MIL-STD-498 was the baseline for certain ISO and IEEE standards that followed it. It also contains much of the material that the subsequent professionalization of project management covered in the Project Management Body of Knowledge (PMBOK). The document "MIL-STD-498 Overview and Tailoring Guidebook" is 98 pages. The "MIL-STD-498 Application and Reference Guidebook" is 516 pages. Associated to these were document templates, or Data Item Descriptions, described below, bringing documentation and process order that could scale to projects of the size humans were then conducting (aircraft, battleships, canals, dams, factories, satellites, submarines, etcetera).
It was one of the few military standards that survived the "Perry Memo", then U.S. Secretary of Defense William Perry's 1994 memorandum commanding the discontinuation of defense standards. However, it was canceled on May 27, 1998, and replaced by the essentially identical demilitarized version EIA J-STD-016 as a process example guide for IEEE 12207. Several programs outside of the U.S. military continued to use the standard due to familiarity and perceived advantages over alternative standards, such as free availability of the standards documents and presence of process detail including contractually-usable Data Item Descriptions.
In military airborne softwar |
https://en.wikipedia.org/wiki/Cyberinfrastructure | United States federal research funders use the term cyberinfrastructure to describe research environments that support advanced data acquisition, data storage, data management, data integration, data mining, data visualization and other computing and information processing services distributed over the Internet beyond the scope of a single institution. In scientific usage, cyberinfrastructure is a technological and sociological solution to the problem of efficiently connecting laboratories, data, computers, and people with the goal of enabling derivation of novel scientific theories and knowledge.
Origin
The term National Information Infrastructure had been popularized by Al Gore in the 1990s. This use of the term "cyberinfrastructure" evolved from the same thinking that produced Presidential Decision Directive NSC-63 on Protecting America's Critical Infrastructures (PDD-63). PDD-63 focuses on the security and vulnerability of the nation's "cyber-based information systems" as well as the critical infrastructures on which America's military strength and economic well-being depend, such as the electric power grid, transportation networks, potable water and wastewater infrastructures.
The term "cyberinfrastructure" was used in a press briefing on PDD-63 on May 22, 1998 with Richard A. Clarke, then national coordinator for security, infrastructure protection, and counter-terrorism, and Jeffrey Hunker, who had just been named director of the critical infrastructure assurance office. Hunker stated:
"One of the key conclusions of the President's commission that laid the intellectual framework for the President's announcement today was that while we certainly have a history of some real attacks, some very serious, to our cyber-infrastructure, the real threat lay in the future. And we can't say whether that's tomorrow or years hence. But we've been very successful as a country and as an economy in wiring together our critical infrastructures. This is a development that's |
https://en.wikipedia.org/wiki/S%20cell | S cells are cells which release secretin, found in the jejunum and duodenum. They are stimulated by a drop in pH to 4 or below in the small intestine's lumen. The released secretin will increase the secretion of bicarbonate (HCO3−) into the lumen, via the pancreas. This is primarily accomplished by an increase in cyclic AMP that activates CFTR to release chloride anions into the lumen. The luminal Cl− is then involved in a bicarbonate transporter protein exchange, in which the chloride is reabsorbed by the cell and HCO3− is secreted into the lumen. S cells are also one of the main producers of cyclosamatin.
Human cells
Digestive system |
https://en.wikipedia.org/wiki/Jesse%20Gelsinger | Jesse Gelsinger (June 18, 1981 – September 17, 1999) was the first person publicly identified as having died in a clinical trial for gene therapy. Gelsinger suffered from ornithine transcarbamylase deficiency, an X-linked genetic disease of the liver, the symptoms of which include an inability to metabolize ammonia – a byproduct of protein breakdown. The disease is usually fatal at birth, but Gelsinger had a milder form of the disease, in which the ornithine transcarbamylase gene is mutated in only part of the patient's cells, a condition known as somatic mosaicism. As his deficiency was partial, Gelsinger managed to survive on a restricted diet and special medications.
Gelsinger joined a clinical trial run by the University of Pennsylvania that aimed at developing a treatment for infants born with the severe form of the disease. On September 13, 1999, Gelsinger was injected with an adenoviral vector carrying a corrected gene to test the safety of the procedure. He died four days later at the age of 18, on September 17, apparently having suffered a massive immune response triggered by the use of the viral vector to transport the gene into his cells, leading to multiple organ failure and brain death.
A Food and Drug Administration (FDA) investigation concluded that the scientists involved in the trial, including the co-investigator James Wilson (Director of the Institute for Human Gene Therapy), broke several rules of conduct:
Inclusion of Gelsinger as a substitute for another volunteer who dropped out, despite Gelsinger's having high ammonia levels that should have led to his exclusion from the trial.
Failure by the university to report that two patients had experienced serious side effects from the gene therapy.
Failure to disclose, in the informed-consent documentation, the deaths of monkeys given a similar treatment.
The University of Pennsylvania later issued a rebuttal, but the university and Children's National Medical Center each agreed to pay more than $5 |
https://en.wikipedia.org/wiki/Totally%20positive%20matrix | In mathematics, a totally positive matrix is a square matrix in which all the minors are positive: that is, the determinant of every square submatrix is a positive number. A totally positive matrix has all entries positive, so it is also a positive matrix; and it has all principal minors positive (and positive eigenvalues). A symmetric totally positive matrix is therefore also positive-definite. A totally non-negative matrix is defined similarly, except that all the minors must be non-negative (positive or zero). Some authors use "totally positive" to include all totally non-negative matrices.
Definition
Let
be an n × n matrix. Consider any and any p × p submatrix of the form
where:
Then A is a totally positive matrix if:
for all submatrices that can be formed this way.
History
Topics which historically led to the development of the theory of total positivity include the study of:
the spectral properties of kernels and matrices which are totally positive,
ordinary differential equations whose Green's function is totally positive (by M. G. Krein and some colleagues in the mid-1930s),
the variation diminishing properties (started by I. J. Schoenberg in 1930),
Pólya frequency functions (by I. J. Schoenberg in the late 1940s and early 1950s).
Examples
For example, a Vandermonde matrix whose nodes are positive and increasing is a totally positive matrix.
See also
Compound matrix |
https://en.wikipedia.org/wiki/Collapsar | A collapsar is a star which has undergone gravitational collapse. When a star no longer has enough fuel for significant fusion reactions, there are three possible outcomes, depending on the star's mass: If it is less than the Chandrasekhar limit (1.4 solar masses), the star will stabilize and shrink, becoming a white dwarf; between the Chandrasekhar limit and the Tolman–Oppenheimer–Volkoff limit (approximately 3 solar masses), it will become a neutron star; and above the Tolman–Oppenheimer–Volkoff limit, the star will become a black hole. However, it is theorized that the high density of neutron star cores allow for quark matter and, as a result, a star that is more massive than even the Tolman–Oppenheimer–Volkoff limit, yet still isn't a black hole.
See also
List of collapsars
Shell collapsar
Gamma-ray burst
Compact star |
https://en.wikipedia.org/wiki/Beam%27s%20eye%20view | Beam's eye view (abbreviated BEV) is an imaging technique used in radiation therapy for quality assurance and planning of external beam radiotherapy (EBRT). These are primarily used to ensure that the relative orientation of the patient and the treatment machine are correct. The BEV image will typically include the images of the patient's anatomy and the beam modifiers, such as jaws or multi-leaf collimators (MLCs).
Generation of Beam's Eye Views
Physical Construction:
BEV's can be generated by exposing a high energy film (similar to photographic film) or an Electronic Portal Imaging Device (EPID) with the treatment beam itself after it passes through the patient and any beam modifiers (such as blocks). Although this type of image is an excellent indication of the basic quality of the treatment plan, the quality of film images can be poor.
A BEV can be created using a radiation therapy simulator which mimics the treatment geometry (couch angle, gantry angle, etc.) using an X-ray source instead of the higher energy treatment source. The jaws and blocks can be imaged on the same film as the patient's landmarks.
Artificial Reconstruction: The BEV can be created using a Digitally Reconstructed Radiograph (or DRR) that is created from a computed tomography (or CT) data set. This image would contain the same treatment plan information, but the patient image is reconstructed from the CT image data using a physics model. |
https://en.wikipedia.org/wiki/Miller%20Puckette | Miller Smith Puckette (born 1959) is the associate director of the Center for Research in Computing and the Arts as well as a professor of music at the University of California, San Diego, where he has been since 1994.
Puckette is known for authoring Max, a graphical development environment for music and multimedia synthesis, which he developed while working at IRCAM in the late 1980s. He is also the author of Pure Data (Pd), a real-time performing platform for audio, video and graphical programming language for the creation of interactive computer music and multimedia works, written in the 1990s with input from many others in the computer music and free software communities.
Biography
An alumnus of St. Andrew's-Sewanee School in Tennessee, Miller Puckette got involved in computer music in 1979 at MIT with Barry Vercoe. In 1979 he became a Putnam Fellow.
He earned a Ph.D. in mathematics from Harvard University in 1986 after completing an undergraduate degree at MIT in 1980. He was a member of the MIT Media Lab from its opening in 1985 until 1987 before continuing his research at IRCAM, and since 1997 has been a part of the Global Visual Music project.
He used Max to complete his first work, which is called Pluton from the second work of Manoury' series called Sonus ex Machina.
He is the 2008 SEAMUS Award Recipient.
On May 11, 2011, he received the title of Doctor Honoris Causa from the University of Mons.
On July 21, 2012, he received an Honorary Degree from Bath Spa University in recognition of his extraordinary contribution to computer music research.
He was the recipient of the Gold Medal at the 1975 Math Olympiads and the Silver Medal at the 1976 Math Olympiads.
Selected publications
For a full list, see: http://msp.ucsd.edu/publications.html
Puckette, Miller (2004) “Who Owns our Software?: A first-person case study” Proceedings, ISEA, pp. 200–202, republished in September 2009 issue of Montréal: Communauté électroacoustique canadienne / Canadian Electro |
https://en.wikipedia.org/wiki/Stylometry | Stylometry is the application of the study of linguistic style, usually to written language. It has also been applied successfully to music, paintings, and chess.
Stylometry is often used to attribute authorship to anonymous or disputed documents. It has legal as well as academic and literary applications, ranging from the question of the authorship of Shakespeare's works to forensic linguistics and has methodological similarities with the analysis of text readability.
Stylometry may be used to unmask pseudonymous or anonymous authors, or to reveal some information about the author short of a full identification. Authors may use adversarial stylometry to resist this identification by eliminating their own stylistic characteristics without changing the meaningful content of their communications. It can defeat analyses that do not account for its possibility, but the ultimate effectiveness of stylometry in an adversarial environment is uncertain: stylometric identification may not be reliable, but nor can non-identification be guaranteed; adversarial stylometry's practice itself may be detectable.
History
Stylometry grew out of earlier techniques of analyzing texts for evidence of authenticity, author identity, and other questions.
The modern practice of the discipline received publicity from the study of authorship problems in English Renaissance drama. Researchers and readers observed that some playwrights of the era had distinctive patterns of language preferences, and attempted to use those patterns to identify authors of uncertain or collaborative works. Early efforts were not always successful: in 1901, one researcher attempted to use John Fletcher's preference for " 'em", the contractional form of "them", as a marker to distinguish between Fletcher and Philip Massinger in their collaborations—- but he mistakenly employed an edition of Massinger's works in which the editor had expanded all instances of " 'em" to "them".
The basics of stylometry were |
https://en.wikipedia.org/wiki/Thrombospondin | Thrombospondins (TSPs) are a family of secreted glycoproteins with antiangiogenic functions. Due to their dynamic role within the extracellular matrix they are considered matricellular proteins. The first member of the family, thrombospondin 1 (THBS1), was discovered in 1971 by Nancy L. Baenziger.
Types
The thrombospondins are a family of multifunctional proteins. The family consists of thrombospondins 1-5 and can be divided into 2 subgroups: A, which contains TSP-1 and TSP-2, and B, which contains TSP-3, TSP-4 and TSP-5 (also designated cartilage oligomeric protein or COMP). TSP-1 and TSP-2 are homotrimers, consisting of three identical subunits, whereas TSP-3, TSP-4 and TSP-5 are homopentamers.
TSP-1 and TSP-2 are produced by immature astrocytes during brain development, which promotes the development of new synapses.
Thrombospondin 1
Thrombospondin 1 (TSP-1) is encoded by THBS1. It was first isolated from platelets that had been stimulated with thrombin, and so was designated 'thrombin-sensitive protein'. Since its first recognition, functions for TSP-1 have been found in multiple biological processes including angiogenesis, apoptosis, activation of TGF-beta and Immune regulation. As such, TSP-1 is designated a multifunctional protein.
TSP-1 has multiple receptors, among which CD36, CD47 and integrins are of particular note.
TSP-1 is antiangiogenic, inhibiting the proliferation and migration of endothelial cells by interactions with CD36 expressed on their surface of these cells. Inhibitory peptides and fragments of TSP1 bind to CD36, leading to the expression of FAS ligand (FasL), which activates its specific, ubiquitous receptor, Fas. This leads to the activation of caspases and apoptosis of the cell. Since tumors overexpressing TSP-1 typically grow slower, exhibit less angiogenesis, and have fewer metastases, TSP1 is an attractive target for cancer treatment. Because TSP1 is extremely large (~120 kDa monomer), not very abundant and exerts multiple actio |
https://en.wikipedia.org/wiki/Hazard%20pointer | In a multithreaded computing environment, hazard pointers are one approach to solving the problems posed by dynamic memory management of the nodes in a lock-free data structure. These problems generally arise only in environments that don't have automatic garbage collection.
Any lock-free data structure that uses the compare-and-swap primitive must deal with the ABA problem. For example, in a lock-free stack represented as an intrusively linked list, one thread may be attempting to pop an item from the front of the stack (A → B → C). It remembers the second-from-top value "B", and then performs compare_and_swap(target=&head, newvalue=B, expected=A). Unfortunately, in the middle of this operation, another thread may have done two pops and then pushed A back on top, resulting in the stack (A → C). The compare-and-swap succeeds in swapping `head` with `B`, and the result is that the stack now contains garbage (a pointer to the freed element "B").
Furthermore, any lock-free algorithm containing code of the form
Node* currentNode = this->head; // assume the load from "this->head" is atomic
Node* nextNode = currentNode->next; // assume this load is also atomic
suffers from another major problem, in the absence of automatic garbage collection. In between those two lines, it is possible that another thread may pop the node pointed to by this->head and deallocate it, meaning that the memory access through currentNode on the second line reads deallocated memory (which may in fact already be in use by some other thread for a completely different purpose).
Hazard pointers can be used to address both of these problems. In a hazard-pointer system, each thread keeps a list of hazard pointers indicating which nodes the thread is currently accessing. (In many systems this "list" may be probably limited to only one or two elements.) Nodes on the hazard pointer list must not be modified or deallocated by any other thread.
When a thread wishes to remove a node, it places |
https://en.wikipedia.org/wiki/Malacia | Malacia is abnormal softening of a biological tissue, most often cartilage. The word is derived from Greek μαλακός, malakos = soft. Usually the combining form -malacia suffixed to another combining form that denotes the affected tissue assigns a more specific name to each such disorder, as follows:
Osteomalacia (rickets), a bone disorder from vitamin D deficiency
Chondromalacia, softening of cartilage (often refers to chondromalacia patellae when mentioned without further specification)
Chondromalacia patellae, a disorder of cartilage under the kneecap
Bronchomalacia, a disorder of the bronchial tubes' cartilage
Laryngomalacia, a disorder of the larynx's cartilage
Tracheomalacia, a disorder of the trachea's cartilage
Keratomalacia, an eye disorder from vitamin A deficiency
Myelomalacia, a disorder of the spinal cord
Cerebral softening (encephalomalacia), localized softening of brain tissue
External links
Definition at MedineNet.com
Medical terminology |
https://en.wikipedia.org/wiki/Internal%20conversion%20coefficient | In nuclear physics, the internal conversion coefficient describes the rate of internal conversion.
The internal conversion coefficient may be empirically determined by the following formula:
There is no valid formulation for an equivalent concept for E0 (electric monopole) nuclear transitions.
There are theoretical calculations that can be used to derive internal conversion coefficients. Their accuracy is not generally under dispute, but since the quantum mechanical models they depend on only take into account electromagnetic interactions between the nucleus and electrons, there may be unforeseen effects.
Internal conversion coefficients can be looked up from tables, but this is time-consuming. Computer programs have been developed (see the BrIcc Program) which present internal conversion coefficients quickly and easily.
Theoretical calculations of interest are the Rösel, Hager-Seltzer, and the Band, superseded by the Band-Raman calculation called BrIcc.
The Hager-Seltzer calculations omit the M and higher-energy shells on the grounds (usually valid) that those orbitals have little electron density at the nucleus and can be neglected. To first approximation this assumption is valid, upon comparing several internal conversion coefficients for different isotopes for transitions of about 100 keV.
The Band and Band-Raman calculations assume that the M shell may contribute to internal conversion to a non-negligible extent, and incorporates a general term (called "N+") which takes into account the small effect of any higher shells there may be, while the Rösel calculation works like the Band, but does not assume that all shells contribute and so generally terminates at the N shell.
Additionally, the Band-Raman calculation can now consider ("frozen orbitals") or neglect ("no hole") the effect of the electron vacancy; the frozen-orbitals approximation is considered generally superior. |
https://en.wikipedia.org/wiki/Recrudescence | Recrudescence is the recurrence of an undesirable condition. In medicine, it is usually defined as the recurrence of symptoms after a period of remission or quiescence, in which sense it can sometimes be synonymous with relapse. In a narrower sense, it can also be such a recurrence with higher severity than before the remission. "Relapse" conventionally has a specific (albeit somewhat illogical) meaning when used in relation to malaria (see below).
Malaria
In malaria, recurrence can take place due to recrudescence; or relapse; or re-infection (via mosquito transmission). Relapse means that a recurrence has been precipitated by a dormant stage in the liver called a "hypnozoite". Thus, relapse is applied only for those plasmodial species that have hypnozoites in the life cycle, such as Plasmodium vivax and P. ovale. On the other hand, recrudescence means that circulating, multiplying parasites are detected after having persisted in the bloodstream (or elsewhere) at undetectable levels for a period of time, as merozoites (as opposed to hypnozoites). This term is applied for Plasmodium species that are not associated with hypnozoite-mediated recurrences, such as P. falciparum, P. malariae, and P. knowlesi. Recrudescence is also used for malarial recurrence caused by drug-resistant strains of P. vivax and P. ovale where parasites remained in the bloodstream despite treatment.
Melioidosis
In melioidosis, a recurrent infection can be due to re-infection and relapse. Re-infection is a recurrence of symptoms due to an infection with a new strain of Burkholderia pseudomallei following the eradication therapy of melioidosis. Meanwhile, relapse are those who presented with melioidosis symptoms due to failure to clear the infection in the bloodstream after completion of eradication therapy. On the other hand, recrudescence is the recurrence of melioidosis symptoms during the eradication therapy.
Bovine viral diarrhoea
The bovine viral diarrhoea virus (bovine virus diarrhea) i |
https://en.wikipedia.org/wiki/Neighbor%20Discovery%20Protocol | The Neighbor Discovery Protocol (NDP), or simply Neighbor Discovery (ND), is a protocol of the Internet protocol suite used with Internet Protocol Version 6 (IPv6). It operates at the link layer of the Internet model, and is responsible for gathering various information required for network communication, including the configuration of local connections and the domain name servers and gateways.
The protocol defines five ICMPv6 packet types to perform functions for IPv6 similar to the Address Resolution Protocol (ARP) and Internet Control Message Protocol (ICMP) Router Discovery and Router Redirect protocols for IPv4. It provides many improvements over its IPv4 counterparts (RFC 4861, section 3.1). For example, it includes Neighbor Unreachability Detection (NUD), thus improving robustness of packet delivery in the presence of failing routers or links, or mobile nodes.
The Inverse Neighbor Discovery (IND) protocol extension (RFC 3122) allows nodes to determine and advertise an IPv6 address corresponding to a given link-layer address, similar to Reverse ARP for IPv4.
The Secure Neighbor Discovery Protocol (SEND), a security extension of NDP, uses Cryptographically Generated Addresses (CGA) and the Resource Public Key Infrastructure (RPKI) to provide an alternative mechanism for securing NDP with a cryptographic method that is independent of IPsec. Neighbor Discovery Proxy (ND Proxy) (RFC 4389) provides a service similar to IPv4 Proxy ARP and allows bridging multiple network segments within a single subnet prefix when bridging cannot be done at the link layer.
Functions
NDP defines five ICMPv6 packet types for the purpose of router solicitation, router advertisement, neighbor solicitation, neighbor advertisement, and network redirects.
Router Solicitation (Type 133) Hosts inquire with Router Solicitation messages to locate routers on an attached link. Routers which forward packets not addressed to them generate Router Advertisements immediately upon receipt of thi |
https://en.wikipedia.org/wiki/T-norm | In mathematics, a t-norm (also T-norm or, unabbreviated, triangular norm) is a kind of binary operation used in the framework of probabilistic metric spaces and in multi-valued logic, specifically in fuzzy logic. A t-norm generalizes intersection in a lattice and conjunction in logic. The name triangular norm refers to the fact that in the framework of probabilistic metric spaces t-norms are used to generalize the triangle inequality of ordinary metric spaces.
Definition
A t-norm is a function T: [0, 1] × [0, 1] → [0, 1] that satisfies the following properties:
Commutativity: T(a, b) = T(b, a)
Monotonicity: T(a, b) ≤ T(c, d) if a ≤ c and b ≤ d
Associativity: T(a, T(b, c)) = T(T(a, b), c)
The number 1 acts as identity element: T(a, 1) = a
Since a t-norm is a binary algebraic operation on the interval [0, 1], infix algebraic notation is also common, with the t-norm usually denoted by .
The defining conditions of the t-norm are exactly those of a partially ordered abelian monoid on the real unit interval [0, 1]. (Cf. ordered group.) The monoidal operation of any partially ordered abelian monoid L is therefore by some authors called a triangular norm on L.
Classification of t-norms
A t-norm is called continuous if it is continuous as a function, in the usual interval topology on [0, 1]2. (Similarly for left- and right-continuity.)
A t-norm is called strict if it is continuous and strictly monotone.
A t-norm is called nilpotent if it is continuous and each x in the open interval (0, 1) is nilpotent, that is, there is a natural number n such that x ... x (n times) equals 0.
A t-norm is called Archimedean if it has the Archimedean property, that is, if for each x, y in the open interval (0, 1) there is a natural number n such that x ... x (n times) is less than or equal to y.
The usual partial ordering of t-norms is pointwise, that is,
T1 ≤ T2 if T1(a, b) ≤ T2(a, b) for all a, b in [0, 1].
As functions, pointwise larger t-norms are sometimes call |
https://en.wikipedia.org/wiki/List%20of%20common%20household%20pests | This is a list of common household pests – undesired animals that have a history of living, invading, causing damage, eating human foods, acting as disease vectors or causing other harms in human habitation.
Mammals
Mice
Field mice
House mice
Possums
Brushtail possum
Ringtail possum
Rats
Black rats
Brown rats
Wood rats
Cotton rats
Invertebrates
Ants
Argentine ants
Carpenter ants
Fire ants
Odorous house ants
Pharaoh ants
Thief ants
Bed bugs
Beetles
Woodworms
Death watch beetles
Furniture beetles
Weevils
Maize weevil
Rice weevil
Carpet beetles
Fur beetles
Varied carpet beetles
Spider beetles
Mealworm beetles
Centipedes
House centipedes
Cockroaches
Brown-banded cockroaches
German cockroaches
American cockroaches
Oriental cockroaches
Dust mites
Earwigs
Crickets
House crickets
Flies
Bottle flies
Blue bottle flies
Green bottle flies
House flies
Fruit flies
Mosquitoes
Moths
Almond moths
Indianmeal moths
Clothes moths
Common clothes moths
Brown house moths
Paper Lice
Red spiders
Silverfish
Spiders
Termites
Dampwood termites
Subterranean termites
Woodlouse
See also
Home-stored product entomology
List of notifiable diseases
Noxious weed
Pest (organism) |
https://en.wikipedia.org/wiki/Saprobiont | Saprobionts are organisms that digest their food externally and then absorb the products. This process is called saprotrophic nutrition. Fungi are examples of saprobiontic organisms, which are a type of decomposer.
Saprobiontic organisms feed off dead and/or decaying biological materials. Digestion is accomplished by excretion of digestive enzymes which break down cell tissues, allowing saprobionts to extract the nutrients they need while leaving the indigestible waste. This is called extracellular digestion. This is very important in ecosystems, for the nutrient cycle.
Saprobionts should not be confused with detritivores, another class of decomposers which digest internally.
These organisms can be good sources of extracellular enzymes for industrial processes such as the production of fruit juice. For instance, the fungus Aspergillus niger is used to produce pectinase, an enzyme which is used to break down pectin in juice concentrates, making the juice appear more translucent. |
https://en.wikipedia.org/wiki/Mimic%20function | A mimic function changes a file so it assumes the statistical properties of another file . That is, if is the probability of some substring occurring in , then a mimic function , recodes so that approximates for all strings of length less than some . It is commonly considered to be one of the basic techniques for hiding information, often called steganography.
The simplest mimic functions use simple statistical models to pick the symbols in the output. If the statistical model says that item occurs with probability and item occurs with probability , then a random number is used to choose between outputting or with probability or respectively.
Even more sophisticated models use reversible Turing machines. |
https://en.wikipedia.org/wiki/Multi-adjoint%20logic%20programming | Multi-adjoint logic programming defines syntax and semantics of a logic programming program in such a way that the underlying maths justifying the results are a residuated lattice and/or MV-algebra.
The definition of a multi-adjoint logic program is given, as usual in fuzzy logic programming, as a set of weighted rules and facts of a given formal language F. Notice that we are allowed to use different implications in our rules.
Definition: A multi-adjoint logic program is a set P of rules of the form <(A ←i B), δ> such that:
1. The rule (A ←i B) is a formula of F;
2. The confidence factor δ is an element (a truth-value) of L;
3. The head A is an atom;
4. The body B is a formula built from atoms B1, …, Bn (n ≥ 0) by the use of conjunctors, disjunctors, and aggregators.
5. Facts are rules with body ┬.
6. A query (or goal) is an atom intended as a question ?A prompting the system.
Implementations
Implementations of Multi-adjoint logic programming:
Rfuzzy,
Floper,
and more we do not remember now.
Programming languages |
https://en.wikipedia.org/wiki/Waterproofing | Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments or underwater to specified depths.
Water-resistant and waterproof often refer to resistance to penetration of water in its liquid state and possibly under pressure, whereas damp proof refers to resistance to humidity or dampness. Permeation of water vapour through a material or structure is reported as a moisture vapor transmission rate (MVTR).
The hulls of boats and ships were once waterproofed by applying tar or pitch. Modern items may be waterproofed by applying water-repellent coatings or by sealing seams with gaskets or o-rings.
Waterproofing is used in reference to building structures (such as basements, decks, or wet areas), watercraft, canvas, clothing (raincoats or waders), electronic devices and paper packaging (such as cartons for liquids).
In construction
In construction, a building or structure is waterproofed with the use of membranes and coatings to protect contents and structural integrity. The waterproofing of the building envelope in construction specifications is listed under 07 - Thermal and Moisture Protection within MasterFormat 2004, by the Construction Specifications Institute, and includes roofing and waterproofing materials.
In building construction, waterproofing is a fundamental aspect of creating a building envelope, which is a controlled environment. The roof covering materials, siding, foundations, and all of the various penetrations through these surfaces must be water-resistant and sometimes waterproof. Roofing materials are generally designed to be water-resistant and shed water from a sloping roof, but in some conditions, such as ice damming and on flat roofs, the roofing must be waterproof. Many types of waterproof membrane systems are available, including felt paper or tar paper wi |
https://en.wikipedia.org/wiki/Attribute-oriented%20programming | Attribute-oriented programming (@OP) is a technique for embedding metadata, namely attributes, within program code.
Attribute-oriented programming in various languages
Java
With the inclusion of Metadata Facility for Java (JSR-175) into the J2SE 5.0 release it is possible to utilize attribute-oriented programming right out of the box.
XDoclet library makes it possible to use attribute-oriented programming approach in earlier versions of Java.
C#
The C# language has supported attributes from its very first release. These attributes was used to give run-time information and are not used by a preprocessor. Currently with source generators, you can use attributes to drive generation of additional code at compile-time.
UML
The Unified Modeling Language (UML) supports a kind of attribute called stereotypes.
Hack
The Hack programming language supports attributes. Attributes can be attached to various program entities, and information about those attributes can be retrieved at run-time via reflection.
Tools
Annotation Processing Tool (apt)
Spoon, an Annotation-Driven Java Program Transformer
XDoclet, a Javadoc-Driven Program Generator |
https://en.wikipedia.org/wiki/Sperm%20heteromorphism | Sperm heteromorphism is the simultaneous production of two or more distinguishable types of sperm by a single male. The sperm types might differ in size, shape and/or chromosome complement. Sperm heteromorphism is also called sperm polymorphism or sperm dimorphism (for species with two sperm types). Typically, only one sperm type is capable of fertilizing eggs. Fertile types have been called "eusperm" or "eupyrene sperm" and infertile types "parasperm" or "apyrene sperm".
One interpretation of sperm polymorphism is the "kamikaze sperm" hypothesis (Baker and Bellis, 1988), which has been widely discredited in humans. The kamikaze sperm hypothesis states that the polymorphism of sperm is due to a subdivision of sperm into different functional groups. There are those that defend the egg from fertilization by other male sperm, and those that fertilize the egg. However, there is no evidence that the polymorphism of human sperm is for the purpose of antagonizing rival sperm.
Distribution
Sperm heteromorphism is known from several different groups of animals.
Insects
Lepidoptera (i.e. butterflies and moths): Almost all known species produce two sperm types. The fertilizing type has a longer tail and contains a nucleus. The other type is shorter and lacks a nucleus, meaning it contains no genetic information at all.
Drosophila (fruit-flies): the D. obscura group of species in the genus Drosophila is sperm heteromorphic. As with the Lepidoptera, there is a long, fertile type and a short, infertile type. However, the infertile type has a nucleus with a normal, haploid chromosome complement. It is not known why the shorter sperm are infertile, though it has been suggested that the slightly wider head of the infertile type might prevent it from entering the micropyle of the egg.
Diosidae (stalk-eyed flies): several species have a long, fertile type and a shorter infertile type.
Carabidae (ground beetles): some species produce large, infertile sperm that may contain up to 10 |
https://en.wikipedia.org/wiki/How%20to%20Lie%20with%20Statistics | How to Lie with Statistics is a book written by Darrell Huff in 1954, presenting an introduction to statistics for the general reader. Not a statistician, Huff was a journalist who wrote many how-to articles as a freelancer.
The book is a brief, breezy illustrated volume outlining the misuse of statistics and errors in the interpretation of statistics, and how errors create incorrect conclusions.
In the 1960s and 1970s, it became a standard textbook introduction to the subject of statistics for many college students. It has become one of the best-selling statistics books in history, with over one and a half million copies sold in the English-language edition. It has also been widely translated.
Themes of the book include "Correlation does not imply causation" and "Using random sampling". It also shows how statistical graphs can be used to distort reality, for example by truncating the bottom of a line or bar chart, so that differences seem larger than they are, or by representing one-dimensional quantities on a pictogram by two- or three-dimensional objects to compare their sizes, so that the reader forgets that the images do not scale the same way the quantities do.
The original edition contained illustrations by artist Irving Geis. In a UK edition, Geis' illustrations were replaced by cartoons by Mel Calman.
See also
Lies, damned lies, and statistics
Notes |
https://en.wikipedia.org/wiki/Pseudopotential | In physics, a pseudopotential or effective potential is used as an approximation for the simplified description of complex systems. Applications include atomic physics and neutron scattering. The pseudopotential approximation was first introduced by Hans Hellmann in 1934.
Atomic physics
The pseudopotential is an attempt to replace the complicated effects of the motion of the core (i.e. non-valence) electrons of an atom and its nucleus with an effective potential, or pseudopotential, so that the Schrödinger equation contains a modified effective potential term instead of the Coulombic potential term for core electrons normally found in the Schrödinger equation.
The pseudopotential is an effective potential constructed to replace the atomic all-electron potential (full-potential) such that core states are eliminated and the valence electrons are described by pseudo-wavefunctions with significantly fewer nodes. This allows the pseudo-wavefunctions to be described with far fewer Fourier modes, thus making plane-wave basis sets practical to use. In this approach usually only the chemically active valence electrons are dealt with explicitly, while the core electrons are 'frozen', being considered together with the nuclei as rigid non-polarizable ion cores. It is possible to self-consistently update the pseudopotential with the chemical environment that it is embedded in, having the effect of relaxing the frozen core approximation, although this is rarely done. In codes using local basis functions, like Gaussian, often effective core potentials are used that only freeze the core electrons.
First-principles pseudopotentials are derived from an atomic reference state, requiring that the pseudo- and all-electron valence eigenstates have the same energies and amplitude (and thus density) outside a chosen core cut-off radius .
Pseudopotentials with larger cut-off radius are said to be softer, that is more rapidly convergent, but at the same time less transferable, that i |
https://en.wikipedia.org/wiki/Nikolai%20Aleksandrovich%20Kozyrev | Nikolai Alexandrovich Kozyrev (; 2 September 1908 – 27 February 1983) was a Soviet Russian astronomer and astrophysicist.
Biography
He was born in St. Petersburg, and by 1928 he had graduated from the Leningrad State University. In 1931 he began working at the Pulkovo Observatory, located to the south of Leningrad. He was considered to be one of the most promising astrophysicists in Russia. Kozyrev was a victim of the Stalinist purges of the Pulkovo Observatory. Started by the accusations of a disgruntled graduate student, most of the observatory staff died as a result. Kozyrev was arrested in November 1936 and sentenced to 10 years for counterrevolutionary activity. In January 1941, he was given another 10-year sentence for "hostile propaganda". While incarcerated, he was allowed to work in engineering-type jobs. Due to the lobbying by his colleagues, he won an early release from detention in December 1946. As a result of his imprisonment he was mentioned in The Gulag Archipelago by Alexandr Solzhenitsyn.
During his imprisonment, Kozyrev attempted to continue working on purely theoretical physics. He considered the problem of the energy source of stars and formulated a theory. But in his isolation, he was unaware of the discovery of nuclear energy. After his release, Kozyrev refused to believe the theory that stars are powered by nuclear fusion.
Publications
He is most noted for his observation of the transient lunar phenomenon in the crater Alphonsus on the Moon. In 1958 he observed a patch of white within the crater, and a spectrum of the area appeared to reveal an emission cloud of carbon particles. Transient lunar phenomenon had long recorded what appeared to be temporary emissions on the lunar surface, and Kozyrev's observation was the first observation of the kind, and appeared to provide confirmation that the Moon was volcanically active.
In 1953, Kozyrev attempted to analyze the phenomenon of ashen light, a nocturnal air glow on Venus whose existence r |
https://en.wikipedia.org/wiki/Spermatheca | The spermatheca (pronounced plural: spermathecae ), also called receptaculum seminis (plural: receptacula seminis), is an organ of the female reproductive tract in insects, e.g. ants, bees, some molluscs, oligochaeta worms and certain other invertebrates and vertebrates. Its purpose is to receive and store sperm from the male or, in the case of hermaphrodites, the male component of the body. Spermathecae can sometimes be the site of fertilisation when the oocytes are sufficiently developed.
Some species of animal have multiple spermathecae. For example, certain species of earthworms have four pairs of spermathecae—one pair each in the 6th, 7th, 8th, and 9th segments. The spermathecae receive and store the spermatozoa of another earthworm during copulation. They are lined with epithelium and are variable in shape: some are thin, heavily coiled tubes, while others are vague outpocketings from the main reproductive tract. It is one of the many variations in sexual reproduction.
The nematode Caenorhabditis elegans has two spermathecae, one at the end of each gonad. The C. elegans spermatheca is made up of 24 smooth muscle-like cells that form a stretchable tubular structure. Actin filaments line the spermatheca in a circumferential manner. The C. elegans spermatheca is used as a model to study mechanotransduction.
An apiculturist may examine the spermatheca of a dead queen bee to find out whether it had received sperm from a male. In many species of stingless bees, especially Melipona bicolor, the queen lays her eggs during the provisioning and oviposition process and the spermatheca fertilizes the egg as it passes along the oviduct. The haplo-diploid system of sex determination makes it possible for the queen to choose the sex of the egg.
See also
Cyphopods, sperm receptacles in female millipedes
Female sperm storage
Reproductive system of gastropods |
https://en.wikipedia.org/wiki/Directory%20System%20Agent | A Directory System Agent (DSA) is the element of an X.500 directory service that provides User Agents with access to a portion of the directory (usually the portion associated with a single Organizational Unit). X.500 is an international standard developed by the International Organization for Standardization (ISO) and the International Telecommunication Union (ITU-T). The model and function of a directory system agent are specified in ITU-T Recommendation X.501.
Active Directory
In Microsoft's Active Directory the DSA is a collection of servers and daemon processes that run on Windows Server systems that provide various means for clients to access the Active Directory data store.
Clients connect to an Active Directory DSA using various communications protocols:
LDAP version 3.0—used by Windows 2000 and Windows XP clients
LDAP version 2.0
Security Account Manager (SAM) interface—used by Windows NT clients
MAPI RPC interface—used by Microsoft Exchange Server and other MAPI clients
A proprietary RPC interface—used by Active Directory DSAs to communicate with one another and replicate data amongst themselves |
https://en.wikipedia.org/wiki/Linear%20actuator | A linear actuator is an actuator that creates linear motion (i.e., in a straight line), in contrast to the circular motion of a conventional electric motor. Linear actuators are used in machine tools and industrial machinery, in computer peripherals such as disk drives and printers, in valves and dampers, and in many other places where linear motion is required. Hydraulic or pneumatic cylinders inherently produce linear motion. Many other mechanisms are used to generate linear motion from a rotating motor.
Types
Mechanical actuators
Mechanical linear actuators typically operate by conversion of rotary motion into linear motion. Conversion is commonly made via a few simple types of mechanism:
Screw: leadscrew, screw jack, ball screw and roller screw actuators all operate on the principle of the simple machine known as the screw. By rotating the actuator's nut, the screw shaft moves in a line.
Wheel and axle: Hoist, winch, rack and pinion, chain drive, belt drive, rigid chain and rigid belt actuators operate on the principle of the wheel and axle. A rotating wheel moves a cable, rack, chain or belt to produce linear motion.
Cam: Cam actuators function on a principle similar to that of the wedge, but provide relatively limited travel. As a wheel-like cam rotates, its eccentric shape provides thrust at the base of a shaft.
Some mechanical linear actuators only pull, such as hoists, chain drive and belt drives. Others only push (such as a cam actuator). Pneumatic and hydraulic cylinders, or lead screws can be designed to generate force in both directions.
Mechanical actuators typically convert rotary motion of a control knob or handle into linear displacement via screws and/or gears to which the knob or handle is attached. A jackscrew or car jack is a familiar mechanical actuator. Another family of actuators are based on the segmented spindle. Rotation of the jack handle is converted mechanically into the linear motion of the jack head. Mechanical actuators ar |
https://en.wikipedia.org/wiki/Hypomyces%20lactifluorum | Hypomyces lactifluorum, the lobster mushroom, contrary to its common name, is neither a mushroom nor a crustacean, but rather a parasitic ascomycete fungus that grows on certain species of mushrooms, turning them a reddish orange color that resembles the outer shell of a cooked lobster. H. lactifluorum specifically attacks members of the genera Lactarius and Lactifluus (milk-caps), and Russula (brittlegills), such as Russula brevipes and Lactifluus piperatus in North America. At maturity, H. lactifluorum thoroughly covers its host, rendering it unidentifiable. Lobster mushrooms are widely eaten and enjoyed freshly foraged and cooked. They are commercially marketed and sometimes found in grocery stores; they have been made available at markets in Oregon. They have a seafood-like flavor and a firm, dense texture.
A study from Quebec found that the infected lobster mushroom mostly contains the DNA of the parasitic fungus with only trace amounts of Russula brevipes DNA. This study also measured intermediate products of chemical reactions, or metabolites, in infected and non-infected mushrooms. Metabolites help determine how fungi look and taste, and whether they are fit to eat. They found that through the course of its infection, the parasitic fungus completely alters the diversity and amount of metabolites in Russula brevipes.
While edible, field guides note the hypothetical possibility that H. lactifluorum could parasitize a toxic host and that individuals should avoid consuming lobster mushrooms with unknown hosts, although no instances of toxicity have been recorded. During the course of infection, the chemicals get converted into other more flavorful compounds, making lobster mushrooms more edible. Lactarius piperatus has a spicy, hot flavor but that flavor is counteracted by the parasite H. lactifluorum, making it more edible and delicious. One author notes that he has personally never experienced any trouble from consuming them and another notes that there ha |
https://en.wikipedia.org/wiki/Chromosome%20regions | Several chromosome regions have been defined by convenience in order to talk about gene loci. Most important is the distinction between chromosome region p and chromosome region q. The p region is represented in the shorter arm of the chromosome (p is for petit, French for small) while the q region is in the larger arm (chosen as next letter in alphabet after p). These are virtual regions that exist in all chromosomes.
These are listed as follows:
Chromatids
Arms
Centromere
Kinetochore
Telomere
Sub telomere
satellite chromosome or trabant.
NOR region
During cell division, the molecules that compose chromosomes (DNA and proteins) suffer a condensation process (called the chromatin reticulum condensation) that forms a compact and small complex called a chromatid. The complexes containing the duplicated DNA molecules, the sister chromatids, are attached to each other by the centromere(where the Kinetochore assembles).
If the chromosome is a submetacentric chromosome (One arm big and the other arm small) then the centromere divides each chromosome into two regions: the smaller one, which is the p region, and the bigger one, the q region. The sister chromatids will be distributed to each daughter cell at the end of the cell division. Whereas if the chromosome is isobrachial (centromere at centre and arms of equal length), the p and q system is meaningless.
At either end of a chromosome is a telomere, a cap of DNA that protects the rest of the chromosome from damage. The telomere has repetitive junk DNA and hence any enzymatic damage will not affect the coded regions. The areas of the p and q regions close to the telomeres are the subtelomeres, or subtelomeric regions. The areas closer to the centromere are the pericentronomic regions. Finally, the interstitial regions are the parts of the p and q regions that are close to neither the centromere nor the telomeres, but are roughly in the middle of p or q.
See also
Satellite chromosome |
https://en.wikipedia.org/wiki/Beat%20%28acoustics%29 | In acoustics, a beat is an interference pattern between two sounds of slightly different frequencies, perceived as a periodic variation in volume whose rate is the difference of the two frequencies.
With tuning instruments that can produce sustained tones, beats can be readily recognized. Tuning two tones to a unison will present a peculiar effect: when the two tones are close in pitch but not identical, the difference in frequency generates the beating. The volume varies like in a tremolo as the sounds alternately interfere constructively and destructively. As the two tones gradually approach unison, the beating slows down and may become so slow as to be imperceptible. As the two tones get further apart, their beat frequency starts to approach the range of human pitch perception, the beating starts to sound like a note, and a combination tone is produced.
Mathematics and physics of beat tones
This phenomenon is best known in acoustics or music, though it can be found in any linear system: "According to the law of superposition, two tones sounding simultaneously are superimposed in a very simple way: one adds their amplitudes". If a graph is drawn to show the function corresponding to the total sound of two strings, it can be seen that maxima and minima are no longer constant as when a pure note is played, but change over time: when the two waves are nearly 180 degrees out of phase the maxima of one wave cancel the minima of the other, whereas when they are nearly in phase their maxima sum up, raising the perceived volume.
It can be proven with the help of a sum-to-product trigonometric identity (see List of trigonometric identities) that the envelope of the maxima and minima form a wave whose frequency is half the difference between the frequencies of the two original waves. Consider two sine waves of unit amplitude:
If the two original frequencies are quite close (for example, a difference of approximately twelve hertz), the frequency of the cosine of the rig |
https://en.wikipedia.org/wiki/Extension%20by%20new%20constant%20and%20function%20names | In mathematical logic, a theory can be extended with
new constants or function names under certain conditions with assurance that the extension will introduce
no contradiction. Extension by definitions is perhaps the best-known approach, but it requires
unique existence of an object with the desired property. Addition of new names can also be done
safely without uniqueness.
Suppose that a closed formula
is a theorem of a first-order theory . Let be a theory obtained from by extending its language with new constants
and adding a new axiom
.
Then is a conservative extension of , which means that the theory has the same set of theorems in the original language (i.e., without constants ) as the theory .
Such a theory can also be conservatively extended by introducing a new functional symbol:
Suppose that a closed formula is a theorem of a first-order theory , where we denote . Let be a theory obtained from by extending its language with a new functional symbol (of arity ) and adding a new axiom . Then is a conservative extension of , i.e. the theories and prove the same theorems not involving the functional symbol ).
Shoenfield states the theorem in the form for a new function name, and constants are the same as functions
of zero arguments. In formal systems that admit ordered tuples, extension by multiple constants as shown here
can be accomplished by addition of a new constant tuple and the new constant names
having the values of elements of the tuple.
See also
Conservative extension
Extension by definition |
https://en.wikipedia.org/wiki/Glume | In botany, a glume is a bract (leaf-like structure) below a spikelet in the inflorescence (flower cluster) of grasses (Poaceae) or the flowers of sedges (Cyperaceae). There are two other types of bracts in the spikelets of grasses: the lemma and palea.
In grasses, two bracts known as "glumes" form the lowermost organs of a spikelet (there are usually two but one is sometimes reduced; or rarely, both are absent). Glumes may be similar in form to the lemmas, the bracts at the base of each floret.
In sedges, by contrast, a glume is a scale at the base of each flower in a spikelet. |
https://en.wikipedia.org/wiki/Gumstix | Gumstix is an American multinational corporation headquartered in Redwood City, California. It develops and manufactures small system boards comparable in size to a stick of gum. In 2003, when it was first fully functional, it used ARM architecture system on a chip (SoC) and an operating system based on Linux 2.6 kernel. It has an online tool called Geppetto that allows users to design their own boards. In August 2013 it started a crowd-funding service to allow a group of users that want to get a custom design manufactured to share the setup costs.
See also
Arduino
Embedded system
Raspberry Pi
Stick PC |
https://en.wikipedia.org/wiki/Code%20point | A code point, codepoint or code position is a unique position in a quantized n-dimensional space that has been assigned a semantic meaning.
In other words, a code point is a particular position in a table, where the position has been assigned a meaning. The table has discrete positions (1, 2, 3, 4, but not fractions) and may be one dimensional (a column), two dimensional (like cells in a spreadsheet), three dimensional (sheets in a workbook), etc... in any number of dimensions.
Code points are used in a multitude of formal information processing and telecommunication standards. For example ITU-T Recommendation T.35 contains a set of country codes for telecommunications equipment (originally fax machines) which allow equipment to indicate its country of manufacture or operation. In T.35, Argentina is represented by the code point 0x07, Canada by 0x20, Gambia by 0x41, etc.
In character encoding
Code points are commonly used in character encoding, where a code point is a numerical value that maps to a specific character. In character encoding code points usually represent a single grapheme—usually a letter, digit, punctuation mark, or whitespace—but sometimes represent symbols, control characters, or formatting. The set of all possible code points within a given encoding/character set make up that encoding's codespace.
For example, the character encoding scheme ASCII comprises 128 code points in the range 0hex to 7Fhex, Extended ASCII comprises 256 code points in the range 0hex to FFhex, and Unicode comprises code points in the range 0hex to 10FFFFhex. The Unicode code space is divided into seventeen planes (the basic multilingual plane, and 16 supplementary planes), each with (= 216) code points. Thus the total size of the Unicode code space is 17 × = .
In Unicode
For Unicode, the particular sequence of bits is called a code unit – for the UCS-4 encoding, any code point is encoded as 4-byte (octet) binary numbers, while in the UTF-8 encoding, different code |
https://en.wikipedia.org/wiki/Oenothera%20biennis | Oenothera biennis, the common evening-primrose, is a species of flowering plant in the family Onagraceae, native to eastern and central North America, from Newfoundland west to Alberta, southeast to Florida, and southwest to Texas, and widely naturalized elsewhere in temperate and subtropical regions. Evening primrose oil is produced from the plant.
Other common names include evening star, sundrop, weedy evening primrose, German rampion, hog weed, King's cure-all and fever-plant.
Description
Oenothera biennis usually has a life span of two years (biennial) growing to tall in the seeding year. The leaves are lanceolate, long and wide, produced in a tight rosette the first year, and spirally on a stem the second year. However, plants with annual life cycles are documented, and have been selected for under experimental conditions in environments with low competition.
Growing Cycle
Most commonly, O. biennis grows as a low, spreading herb in the first year, just a few centimetres tall, with its leaves spreading out in a rosette to cover the ground, whilst storing energy in a thick root. In the second year, it grows up much taller, to around 1.6M tall, on a semi-woody stem, which then flowers and seeds. This will usually die at first frosts, but occasionally grows another stem in the third year.
Blooming and Fruiting
Blooming lasts from late spring to late summer. The flowers are hermaphrodite, produced on a tall spike and only last until the following noon. They open visibly fast every evening producing an interesting spectacle, hence the name "evening primrose".
The blooms are yellow, diameter, with four bilobed petals. The flower structure has a bright nectar guide pattern, invisible to the naked eye. This pattern is apparent under ultraviolet light and visible to its pollinators, moths, butterflies, and bees.
The fruit is a capsule long and broad, containing numerous long seeds, released when the capsule splits into four sections at maturity.
Ecology
T |
https://en.wikipedia.org/wiki/Universal%20Personal%20Telecommunications | Universal personal telecommunications (UPT) was a special segment of the international telephone number space which had been set aside for universal personal telephone numbers. This service had been allocated country code +87810 and was completed by a 10-digit subscriber number which provided 10 billion unique numbers. The International Telecommunication Union (ITU) introduced this concept in 2001, referring to it as "global number portability" (not to be confused with number portability).
The delegation of UPT was requested by VisionNG Chairman Herwart Wermescher and was confirmed by Counsellor, SG2 of ITU-TSB Richard Hill on May 21, 2002.
The UPT number allocation was withdrawn in 2022.
The UPT service
The UPT standards have been developed to allow a UPT number to be associated with any device on any network, anywhere in the world. An individual should be able to enter an access code to make or receive calls on any device and can be provisioned as a global mobile telephone number.
UPT allowed ad hoc sharing of physical devices and was intended to be independent of geography or network provider. From the +87810 numbering space, operators could offer their customers next generation services – voice, data, email, SMS, web and location-based services – using a single "number for life" that transcended national boundaries and traditional ways of thinking about communications.
Initially, UPT number blocks were allocated to VoIP, but as technology advanced, UPT was more and more seen as a numbering and addressing solution for Digital Identity and Internet of Things marketplace.
In February 2016, the ITU approved the assignment of a Mobile Country Code and Network Code associated to the UPT Country Code. This allowed for the provision of 10 billion unique IMSI's for the deployment of Global Mobile Services.
UPT service profile
The UPT service profile was a record that contained all information related to a UPT user, which information is required to provide that use |
https://en.wikipedia.org/wiki/Shared-cost%20service | Shared-cost service is a type of telephone call billing where the charge for calling a particular telephone number is partially, but not entirely, paid for by the recipient.
Shared cost numbers normally enable non-geographical or long-distance calls that are priced to the caller as if they were local while the difference is paid by the called party.
See also
Universal International Shared Cost Number, an international shared-cost numbering scheme
External links
ITU ISCS page
Telephone numbers |
https://en.wikipedia.org/wiki/Orthomode%20transducer | An orthomode transducer (OMT) is a waveguide component that is commonly referred to as a polarisation duplexer. Orthomode is a contraction of orthogonal mode. Orthomode transducers serve either to combine or to separate two orthogonally polarized microwave signal paths. One of the paths forms the uplink, which is transmitted over the same waveguide as the received signal path, or downlink path. Such a device may be part of a very small aperture terminal (VSAT) antenna feed or a terrestrial microwave radio feed; for example, OMTs are often used with a feed horn to isolate orthogonal polarizations of a signal and to transfer transmit and receive signals to different ports.
VSAT and satellite Earth station applications
For VSAT modems the transmission and reception paths are at 90° to each other, or in other words, the signals are orthogonally polarized with respect to each other. This orthogonal shift between the two signal paths provides approximately an isolation of 40 dB in the Ku band and Ka band radio frequency bands.
Hence this device serves in an essential role as the junction element of the outdoor unit (ODU) of a VSAT modem. It protects the receiver front-end element (the low-noise block converter, LNB) from burn-out by the power of the output signal generated by the block up converter (BUC). The BUC is also connected to the feed horn through a wave guide port of the OMT junction device.
Orthomode transducers are used in dual-polarized VSATs, in sparsely populated areas, radar antennas, radiometers, and communications links. They are usually connected to the antenna's down converter or LNB and to the high-power amplifier (HPA), attached to a transmitting antenna.
When the transmitted and received radio signal to and from the antenna have two different polarizations (horizontal and vertical), they are said to be orthogonal. This means that the modulation planes of the two radio signal waves are at 90 degrees to each other. The OMT device is used to separ |
https://en.wikipedia.org/wiki/Electron%20transfer | Electron transfer (ET) occurs when an electron relocates from an atom or molecule to another such chemical entity. ET is a mechanistic description of certain kinds of redox reactions involving transfer of electrons.
Electrochemical processes are ET reactions. ET reactions are relevant to photosynthesis and respiration and commonly involve transition metal complexes. In organic chemistry ET is a step in some commercial polymerization reactions. It is foundational to photoredox catalysis.
Classes of electron transfer
Inner-sphere electron transfer
In inner-sphere ET, the two redox centers are covalently linked during the ET. This bridge can be permanent, in which case the electron transfer event is termed intramolecular electron transfer. More commonly, however, the covalent linkage is transitory, forming just prior to the ET and then disconnecting following the ET event. In such cases, the electron transfer is termed intermolecular electron transfer. A famous example of an inner sphere ET process that proceeds via a transitory bridged intermediate is the reduction of [CoCl(NH3)5]2+ by [Cr(H2O)6]2+. In this case, the chloride ligand is the bridging ligand that covalently connects the redox partners.
Outer-sphere electron transfer
In outer-sphere ET reactions, the participating redox centers are not linked via any bridge during the ET event. Instead, the electron "hops" through space from the reducing center to the acceptor. Outer sphere electron transfer can occur between different chemical species or between identical chemical species that differ only in their oxidation state. The latter process is termed self-exchange. As an example, self-exchange describes the degenerate reaction between permanganate and its one-electron reduced relative manganate:
[MnO4]− + [Mn*O4]2− → [MnO4]2− + [Mn*O4]−
In general, if electron transfer is faster than ligand substitution, the reaction will follow the outer-sphere electron transfer.
Often occurs when one/both re |
https://en.wikipedia.org/wiki/Heliotrope%20%28instrument%29 | The heliotrope is an instrument that uses a mirror to reflect sunlight over great distances to mark the positions of participants in a land survey. The heliotrope was invented in 1821 by the German mathematician Carl Friedrich Gauss. The word "heliotrope" is taken from the Greek: helios (), meaning "sun", and tropos (), meaning "turn".
History
Heliotropes were used in surveys from in 1821 through the late 1980s, when GPS measurements replaced the use of the heliotrope in long distance surveys. Colonel Sir George Everest introduced the use of heliotropes into the Great Trigonometric Survey in India around 1831, and the US Coast and Geographic Survey used heliotropes to survey the United States. The Indian specification for heliotropes was updated in 1981, and the American military specification for heliotropes (MIL-H-20194E) was retired on 8 December 1995.
Surveyors used the heliotrope as a specialized form of survey target; it was employed during large triangulation surveys where, because of the great distance between stations (usually twenty miles or more), a regular target would be indistinct or invisible. Heliotropes were often used as survey targets at ranges of over 100 miles. In California, in 1878, a heliotrope on Mount Saint Helena was surveyed by B.A. Colonna of the USCGS from Mount Shasta, a distance of 192 miles (309 km).
The heliotrope was limited to use on sunny days and was further limited (in regions of high temperatures) to mornings and afternoons when atmospheric aberration least affected the instrument-man's line of sight. The heliotrope operator was called a "heliotroper" or "flasher" and would sometimes employ a second mirror for communicating with the instrument station through heliography, a signalling system using impulsed reflecting surfaces. The inventor of the heliograph, a similar instrument specialized for signaling, was inspired by observing the use of heliotropes in the survey of India.
See also
Heliograph, a similar instrument |
https://en.wikipedia.org/wiki/Thyroid%20cartilage | The thyroid cartilage is the largest of the nine cartilages that make up the laryngeal skeleton, the cartilage structure in and around the trachea that contains the larynx. It does not completely encircle the larynx (only the cricoid cartilage encircles it).
Structure
The thyroid cartilage is a hyaline cartilage structure that sits in front of the larynx and above the thyroid gland. The cartilage is composed of two halves, which meet in the middle at a peak called the laryngeal prominence, also called the Adam's apple. In the midline above the prominence is the superior thyroid notch. A counterpart notch at the bottom of the cartilage is called the inferior thyroid notch.
The two halves of the cartilage that make out the outer surfaces extend obliquely to cover the sides of the trachea. The posterior edge of each half articulates with the cricoid cartilage inferiorly at a joint called the cricothyroid joint. The most posterior part of the cartilage also has two projections upwards and downwards. The upper projection is called the superior horn (), and the lower is called the inferior horn. The superior horn is long and narrow, backward, and medialward, and ends in a conical extremity, which gives attachment to the lateral thyrohyoid ligament. The inferior horn is short and thick; it is directed downward, with a slight inclination forward and medialward, and presents, on the medial side of its tip, a small oval articular facet for articulation with the side of the cricoid cartilage.
The entire superior edge of the thyroid cartilage is attached to the hyoid bone by the thyrohyoid membrane. The thyroid cartilage is found between the levels of the C4 to C5 vertebrae.
The oblique line is a line on the thyroid cartilage. It marks the upper lateral borders of the thyroid gland. Two muscles originate along the line, the thyrohyoid muscle and inferior pharyngeal constrictor. The sternothyroid inserts along the line.
Movement of the cartilage at this joint produces a cha |
https://en.wikipedia.org/wiki/Lamina%20%28anatomy%29 | Lamina is a general anatomical term meaning "plate" or "layer". It is used in both gross anatomy and microscopic anatomy to describe structures.
Some examples include:
The laminae of the thyroid cartilage: two leaf-like plates of cartilage that make up the walls of the structure.
The vertebral laminae: plates of bone that form the posterior walls of each vertebra, enclosing the spinal cord.
The laminae of the thalamus: the layers of thalamus tissue.
The lamina propria: a connective tissue layer under the epithelium of an organ.
The nuclear lamina: a dense fiber network inside the nucleus of cells.
The lamina affixa: a layer of epithelium growing on the surface of the thalamus.
Lamina cribrosa with two different meanings. |
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