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https://en.wikipedia.org/wiki/VPg
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VPg (viral protein genome-linked) is a protein that is covalently attached to the 5′ end of positive strand viral RNA and acts as a primer during RNA synthesis in a variety of virus families including Picornaviridae, Potyviridae and Caliciviridae. There are some studies showing that a possible VPg protein is also present in astroviridae, however, experimental evidence for this has not yet been provided and requires further study. The primer activity of VPg occurs when the protein becomes uridylated, providing a free hydroxyl that can be extended by the virally encoded RNA-dependent RNA polymerase. For some virus families, VPg also has a role in translation initiation by acting like a 5' mRNA cap.
VPg was first described in initial investigations of poliovirus RNA as a protein covalently attached to the 5' end of the genome. and later seen in caliciviruses.
Attachment during RNA synthesis
VPg must undergo post-translational uridylylation before it can act as a primer for replication. 3Dpol (the RdRp) is able to synthesize Vpg-pUpU-OH by using a polyA sequence within a stem-loop structure (cis-acting replication element) of 2C-ATPase as a template. Furthermore, a 5' terminal cloverleaf is required in cis to form the 3Dpol preinitiation RNA replication complex involved in uridylylating VPg.
3CDpro (a protease) cleaves VPg from membrane-bound 3AB.
Function as a 5' cap
Studies that used proteinase K to cleave VPg from the viral genome discovered that calicivirus vesicular exa
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https://en.wikipedia.org/wiki/Kitchen%20sink%20regression
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Pejoratively, a kitchen sink regression is a statistical regression which uses a long list of possible independent variables to attempt to explain variance in a dependent variable. In economics, psychology, and other social sciences, regression analysis is typically used deductively to test hypotheses, but a kitchen sink regression does not follow this norm. Instead, the analyst throws "everything but the kitchen sink" into the regression in hopes of finding some statistical pattern.
This type of regression often leads to overfitting (i.e. misleadingly suggesting relationships between independent and dependent variables in the data, which can lead to hasty generalizations). The reason for this is that the more independent variables are included in a regression, the greater the probability that one or more will be found to be statistically significant while in fact having no causal effect on the dependent variable—that is, the more likely the results are to be afflicted with Type I error.
The kitchen sink regression is an example of the practice of data dredging.
References
Regression variable selection
Misuse of statistics
Economics catchphrases
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https://en.wikipedia.org/wiki/TOTP
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TOTP may refer to:
Top of the Pops, a British music chart television programme
Time-based one-time password, algorithm in computer security
See also
Top of the Pops (disambiguation)
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https://en.wikipedia.org/wiki/Alternative%20frequency
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Alternative frequency (or AF) is an option that allows a receiver to re-tune to a different frequency that provides the same station, when the first signal becomes too weak (e.g. when moving out of range). This is often used in car stereo systems, enabled by Radio Data System (RDS), or the U.S.-based Radio Broadcast Data System (RBDS).
Radio technology
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https://en.wikipedia.org/wiki/Multivector
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In multilinear algebra, a multivector, sometimes called Clifford number or multor, is an element of the exterior algebra of a vector space . This algebra is graded, associative and alternating, and consists of linear combinations of simple -vectors (also known as decomposable -vectors or -blades) of the form
where are in .
A -vector is such a linear combination that is homogeneous of degree (all terms are -blades for the same ). Depending on the authors, a "multivector" may be either a -vector or any element of the exterior algebra (any linear combination of -blades with potentially differing values of ).
In differential geometry, a -vector is a vector in the exterior algebra of the tangent vector space; that is, it is an antisymmetric tensor obtained by taking linear combinations of the exterior product of tangent vectors, for some integer . A differential -form is a -vector in the exterior algebra of the dual of the tangent space, which is also the dual of the exterior algebra of the tangent space.
For and , -vectors are often called respectively scalars, vectors, bivectors and trivectors; they are respectively dual to 0-forms, 1-forms, 2-forms and 3-forms.
Exterior product
The exterior product (also called the wedge product) used to construct multivectors is multilinear (linear in each input), associative and alternating. This means for vectors u, v and w in a vector space V and for scalars α, β, the exterior product has the properties:
Linear in an input:
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https://en.wikipedia.org/wiki/IGB%20Eletr%C3%B4nica
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IGB Eletrônica S.A. (Portuguese for IGB Electronics), doing business as Gradiente, is a Brazilian consumer electronics company based in Manaus, and with offices in São Paulo. The company designs and markets many product lines, including video (e.g. televisions, DVD players), audio, home theater, high end acoustics, office and mobile stereo, wireless, mobile/smart phones, and tablets for the Brazilian market.
History
The company was founded in 1964. In 1993 they founded Playtronic, a fully owned subsidiary who licensed the manufacturing of Nintendo consoles in Brazil, and while publishing games for various systems they also provided Portuguese translations of some games (among them, South Park and Shadow Man for the Nintendo 64). However, they stopped the partnership with Nintendo in 2003 because of the high price of the dollar at the time.
In 1997, Gradiente established a joint venture with Finland-based telecommunications manufacturing firm Nokia, where they were granted the license to manufacture variants of Nokia mobile phones locally under the Nokia and Gradiente brand names.
The Gradiente iPhone case
In 2000, Gradiente, now legally known as IGB Eletrônica SA, filed for the brand name "iphone" in Brazil's INPI (National Institute of Industrial Property, the trademark authority). Only by 2008 the Brazilian government granted full brand ownership for Gradiente, and currently (since January 2012), the company is selling Android-based smartphones under this name. Until 2
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https://en.wikipedia.org/wiki/2000%20Costa%20Rican%20census
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The 2000 Costa Rican census was undertaken by the National Institute of Statistics and Census (Instituto Nacional de Estadística y Censos (INEC)).
Description
According to this census, Costa Rica had 3,810,179 inhabitants in 2000, a population density of 74.6/km², and 59% of the people lived in urban areas.
Results by canton
References
Censuses in Costa Rica
2000 in Costa Rica
2000 censuses
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https://en.wikipedia.org/wiki/CLOVER2000
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CLOVER is the name of a series or class of modem modulation techniques (“waveforms”) specifically designed for use over high frequency (HF) radio systems.
CLOVER-II was the first CLOVER waveform sold commercially, developed by Ray Petit, W7GHM, and HAL Communications in 1990–92.
CLOVER-2000 is a higher-rate and wider bandwidth version of CLOVER developed in 1995.
CLOVER-400 is a special 400 Hz wide waveform that was developed for Globe Wireless.
Modulation schemes
In ARQ mode, all CCB's (CLOVER Control Blocks) use BPSK modulation and data blocks may be sent using BPSK, QPSK, 8PSK (see phase-shift keying), 8P2A, or 16P4A (see QAM) modulation. Data is sent in 255-byte blocks. The FEC broadcast mode of CLOVER-2000 is usually disabled although special formats are available for specific applications.
The coding polynomial protocol could be shared after payment in Bit Coin
Radio Interface requirements for CLOVER-2000
The CLOVER waveform offers high performance, error correction, and spectral efficiency. CLOVER is specifically designed for use over HF radio communications links. It may be used with virtually any modern HF SSB radio. However, certain special set-up and adjustment techniques are required to get maximum performance when using CLOVER.
See also
Shortwave
Radioteletype
PSK31
PACTOR
SITOR
References
External links
Signal Identification Wiki CLOVER 2000
ARRL.org CLOVER 2000
Quantized radio modulation modes
Packet radio
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https://en.wikipedia.org/wiki/MT63
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MT63 is a digital radio modulation mode for transmission in high-noise situations. It was developed by Pawel Jalocha, call sign SP9VRC, primarily for keyboard-to-keyboard conversations on HF amateur radio bands.
Description
MT63 distributes the encoding of each character over a long time period, and over several tones. This code and symbol spreading implementation is key to its robustness under less than ideal conditions. The MT63 mode is very tolerant of mistuning; most software will handle 120 Hz tuning offsets under normal conditions.
Latency
MT63 can use either a short or long interleaver. The long interleaver makes the mode more robust against interference, at the cost of increasing latency.
Media
MT63 is seeing a resurgence in its popularity on shortwave with the VOA Radiogram, but the software used to encode the text is not using the Varicode that MT63 used in its original design.
Modern software that supports MT63, such as Fldigi, uses base128, essentially the same as ASCII.
MT63 has been promoted as a modulation format for time signal stations, but this system does not use Varicode.
See also
Walsh code
Varicode
Radioteletype
Shortwave radio
PSK63
References
Related links
"MT63 Technical Information", ZL1BPU website (archived 2008)
"MT63", ZL1BPU website (archived 2008)
BARTG site - British Amateur Radio Teledata Group
Fldigi MT63
MT63 mooted as a time transfer technology
Quantized radio modulation modes
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https://en.wikipedia.org/wiki/INEC
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INEC may refer to:
Ilocos Norte Electric Cooperative
Independent National Electoral Commission, Nigeria
National Institute of Statistics and Census (disambiguation) (Portuguese and Spanish abbreviation: INEC)
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https://en.wikipedia.org/wiki/PSK63
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PSK63 (meaning Phase Shift Keying at a rate of 63 baud) is a digital radio modulation mode used primarily in the amateur radio field to conduct real-time keyboard-to-keyboard informal text chat between amateur radio operators.
History
In April 2003, Skip Teller, KH6TY, the creator of Digipan, requested an addition to Moe (AE4JY) Wheatley's PSKCore DLL to support the PSK63 mode. Subsequently, another mode - PSK125 - has been added to the PSKCore DLL.
Unlike PSK63F, PSK63 does not use forward error correction (FEC).
PSK 63 is twice as fast as PSK63F's but exactly the same speed as PSK125F.
Mode Support
PSK63 is now supported directly in KH6TY's own QuikPSK software, as well as in Digipan, AA6YQ's WinWarbler, F6CTE's MultiPSK, AE4JY's WinPSK, HB9DRV's DM780, PSK31 Deluxe, MMVARI, Fldigi, MIXW, and DL4RCK's RCKRtty. It is also supported in hardware by the Elecraft KX3.
Others are likely to follow, now that version 1.17 of the PSKCore dll supports both PSK31 and PSK63. QuikPSK, MultiPSK and PSK31 Deluxe can decode up to 24 signals simultaneously. QuickPSK has a unique additional capability to send colour thumbnail pictures (32x32 pixel, 16 colours) using the PSK63 mode.
PSK Software Core
A PSK63-only version of the PSKCore dll is also available at KH6TY's web site for use with any software that uses PSKCore to implement PSK31. Simply by replacing the original PSKCore file (it is suggested that you rename the original rather than deleting it) with the new version, the PS
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https://en.wikipedia.org/wiki/National%20Institute%20of%20Statistics%20and%20Census%20of%20Costa%20Rica
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The National Institute of Statistics and Census of Costa Rica (Instituto Nacional de Estadística y Censos de Costa Rica, or INEC, in Spanish) is the governmental institution entrusted with the running of censuses and official surveys in the country. Its main office is located in San José.
History
INEC was first called Oficina Central de Estadística about its foundation in 1861. Later, in 1951, it was called Dirección General de Estadística y Censos, until 1998, when INEC was its legal name. INEC ran its first census in 1864, and the latest was the 10th population and the 6th dwellings census, held in June 2011.
Censuses in Costa Rica
1864. First Population Census.
1883. Second Population Census.
1892. Third Population Census.
1927. Fourth Population Census.
1950. Fifth Population Census.
1963. Sixth Population Census.
1973. Seventh Population Census.
1984. Eight Population Census.
2000. Ninth Population Census.
2011. Tenth Population Census.
2022. Eleventh Population Census.
References
External links
INEC website (in spanish only)
Central American Population Center website (in spanish only). Centro Centroamericano de Población (CCP), organization in charge of demographic studies at University of Costa Rica, has information about the historical census that can be accessed online.
First Population Census.
Second Population Census.
Third Population Census.
Fourth Population Census.
Fifth Population Census.
Sixth Population Census.
Costa Rica
Demographic
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https://en.wikipedia.org/wiki/Napoleon%27s%20theorem
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In geometry, Napoleon's theorem states that if equilateral triangles are constructed on the sides of any triangle, either all outward or all inward, the lines connecting the centres of those equilateral triangles themselves form an equilateral triangle.
The triangle thus formed is called the inner or outer Napoleon triangle. The difference in the areas of the outer and inner Napoleon triangles equals the area of the original triangle.
The theorem is often attributed to Napoleon Bonaparte (1769–1821). Some have suggested that it may date back to W. Rutherford's 1825 question published in The Ladies' Diary, four years after the French emperor's death, but the result is covered in three questions set in an examination for a Gold Medal at the University of Dublin in October, 1820, whereas Napoleon died the following May.
Proofs
In the figure above, is the original triangle. are equilateral triangles constructed on its sides' exteriors, and points are the centroids of those triangles. The theorem for outer triangles states that triangle (green) is equilateral.
A quick way to see that is equilateral is to observe that becomes under a clockwise rotation of 30° around and a homothety of ratio with the same center, and that also becomes after a counterclockwise rotation of 30° around and a homothety of ratio with the same center. The respective spiral similarities are That implies and the angle between them must be 60°.
There are in fact many proofs of the theor
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https://en.wikipedia.org/wiki/Tensor%20product%20of%20Hilbert%20spaces
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In mathematics, and in particular functional analysis, the tensor product of Hilbert spaces is a way to extend the tensor product construction so that the result of taking a tensor product of two Hilbert spaces is another Hilbert space. Roughly speaking, the tensor product is the metric space completion of the ordinary tensor product. This is an example of a topological tensor product. The tensor product allows Hilbert spaces to be collected into a symmetric monoidal category.
Definition
Since Hilbert spaces have inner products, one would like to introduce an inner product, and therefore a topology, on the tensor product that arises naturally from those of the factors. Let and be two Hilbert spaces with inner products and respectively. Construct the tensor product of and as vector spaces as explained in the article on tensor products. We can turn this vector space tensor product into an inner product space by defining
and extending by linearity. That this inner product is the natural one is justified by the identification of scalar-valued bilinear maps on and linear functionals on their vector space tensor product. Finally, take the completion under this inner product. The resulting Hilbert space is the tensor product of and
Explicit construction
The tensor product can also be defined without appealing to the metric space completion. If and are two Hilbert spaces, one associates to every simple tensor product the rank one operator from to that maps a given
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https://en.wikipedia.org/wiki/PACTOR
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PACTOR is a radio modulation mode used by amateur radio operators, marine radio stations, military or government users such as the US Department of Homeland Security, and radio stations in isolated areas to send and receive digital information via radio.
PACTOR is an evolution of both AMTOR and packet radio; its name is a portmanteau of these two technologies' names.
PACTOR uses a combination of simple FSK modulation, and the ARQ protocol for robust error detection and data throughput. Generational improvements to PACTOR include PACTOR II, PACTOR III, and PACTOR IV which are capable of higher speed transmission. PACTOR is most commonly used on frequencies between 1 MHz and 30 MHz.
History
PACTOR (Latin: The mediator) was developed by Special Communications Systems GmbH (SCS) and released to the public in 1991.
PACTOR was developed in order to improve the reception of digital data when the received signal was weak or noisy. It combines the bandwidth efficiency of packet radio with the error-correction (CRC) and automatic repeat request (ARQ) of AMTOR. Amateur radio operators were instrumental in developing and implementing these digital modes.
Current uses
PACTOR radio equipment consists of an HF transceiver, a computer and a terminal node controller. Software running on the computer drives the terminal node controller. The most commonly used amateur program for this purpose is Airmail.
PACTOR is used by Amateur Bulletin board system operators to exchange public messag
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https://en.wikipedia.org/wiki/Hyperconjugation
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In organic chemistry, hyperconjugation (σ-conjugation or no-bond resonance) refers to the delocalization of electrons with the participation of bonds of primarily σ-character. Usually, hyperconjugation involves the interaction of the electrons in a sigma (σ) orbital (e.g. C–H or C–C) with an adjacent unpopulated non-bonding p or antibonding σ* or π* orbitals to give a pair of extended molecular orbitals. However, sometimes, low-lying antibonding σ* orbitals may also interact with filled orbitals of lone pair character (n) in what is termed negative hyperconjugation. Increased electron delocalization associated with hyperconjugation increases the stability of the system. In particular, the new orbital with bonding character is stabilized, resulting in an overall stabilization of the molecule. Only electrons in bonds that are in the β position can have this sort of direct stabilizing effect — donating from a sigma bond on an atom to an orbital in another atom directly attached to it. However, extended versions of hyperconjugation (such as double hyperconjugation) can be important as well. The Baker–Nathan effect, sometimes used synonymously for hyperconjugation, is a specific application of it to certain chemical reactions or types of structures.
Applications
Hyperconjugation can be used to rationalize a variety of chemical phenomena, including the anomeric effect, the gauche effect, the rotational barrier of ethane, the beta-silicon effect, the vibrational frequency o
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https://en.wikipedia.org/wiki/Domeykite
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Domeykite is a copper arsenide mineral, Cu3As. It crystallizes in the isometric system, although crystals are very rare. It typically forms as irregular masses or botryoidal forms. It is an opaque, white to gray (weathers brassy) metallic mineral with a Mohs hardness of 3 to 3.5 and a specific gravity of 7.2 to 8.1
It was first described in 1845 in the Algodones mines, Coquimbo, Chile. It was named after Polish mineralogist Ignacy Domeyko (1802–1889) by Wilhelm Haidinger.
Uses
Domeykite, being a minor copper ore, is used for obtaining copper. It can also be polished and used for ornamental purposes.
See also
List of minerals
List of minerals named after people
References
Copper(I) minerals
Arsenide minerals
Cubic minerals
Minerals in space group 220
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https://en.wikipedia.org/wiki/OSAT
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OSAT may refer to:
Open-source appropriate technology
Outsource semiconductor assembly and test, see Semiconductor consolidation
See also
Osat, in Bosnia and Herzegovina
One School at a Time (OSAAT)
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https://en.wikipedia.org/wiki/ABTS
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In biochemistry, ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) is a chemical compound used to observe the reaction kinetics of specific enzymes. A common use for it is in the enzyme-linked immunosorbent assay (ELISA) to detect the binding of molecules to each other.
It is commonly used as a substrate with hydrogen peroxide for a peroxidase enzyme (such as horseradish peroxidase) or alone with blue multicopper oxidase enzymes (such as laccase or bilirubin oxidase). Its use allows the reaction kinetics of peroxidases themselves to be followed. In this way it also can be used to indirectly follow the reaction kinetics of any hydrogen peroxide-producing enzyme, or to simply quantify the amount of hydrogen peroxide in a sample.
The formal reduction potentials for ABTS are high enough for it to act as an electron donor for the reduction of oxo species such as molecular oxygen and hydrogen peroxide, particularly at the less-extreme pH values encountered in biological catalysis. Under these conditions, the sulfonate groups are fully deprotonated and the mediator exists as a dianion.
ABTS–· + e– → ABTS2– E° = 0.67 V vs SHE
ABTS + e– → ABTS–· E° = 1.08 V vs SHE
This compound is chosen because the enzyme facilitates the reaction with hydrogen peroxide, turning it into a green and soluble end-product. Its new absorbance maximum of 420 nm light (ε = 3.6 × 104 M–1 cm–1) can easily be followed with a spectrophotometer, a common laboratory instrument.
It is sometimes u
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https://en.wikipedia.org/wiki/KIIS%20106.5
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KIIS 1065 (call sign: 2WFM) is a commercial FM radio station in Sydney, Australia, on a frequency of 106.5 MHz. KIIS 1065 is one of the flagship stations on ARN's KIIS Network. The station's headline show is The Kyle and Jackie O Show.
History
2UW
The station, now known as KIIS, began life as 2UW, commencing transmission on 13 February 1925 on 1125 kHz on the AM band. On 1 September 1935, the frequency changed to 1110 kHz and in 1978 changed again to 1107 kHz. 2UW was the home of many live radio plays and had studios for live programmes at Market Street in Sydney, near the intersection with George Street.
The management of 2UW moved the station to 365 Kent Street Sydney although for a time they retained the Market Street live audience theatre that had been used for live plays. One of its early breakfast presenters, Russ Walkington, had a character known as Gerald the Grasshopper who pre-dated Sammy Sparrow who appeared on 2UE with Gary O'Callaghan. In 1935 it became the first radio station outside the United States (and thus the first in both the British Empire and the Southern Hemisphere) to broadcast 24 hours a day. During the 1940s and 1950s the format spread throughout the country and by the end of the 1960s, almost all commercial radio stations in Australia were broadcasting day-round.
From the early 1960s, 2UW moved away from its older audience and actively pursued the youth market through the introduction of a Top 40 format in response to the music coming from th
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https://en.wikipedia.org/wiki/Unit%20propagation
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Unit propagation (UP) or Boolean Constraint propagation (BCP) or the one-literal rule (OLR) is a procedure of automated theorem proving that can simplify a set of (usually propositional) clauses.
Definition
The procedure is based on unit clauses, i.e. clauses that are composed of a single literal, in conjunctive normal form. Because each clause needs to be satisfied, we know that this literal must be true. If a set of clauses contains the unit clause , the other clauses are simplified by the application of the two following rules:
every clause (other than the unit clause itself) containing is removed (the clause is satisfied if is);
in every clause that contains this literal is deleted ( can not contribute to it being satisfied).
The application of these two rules lead to a new set of clauses that is equivalent to the old one.
For example, the following set of clauses can be simplified by unit propagation because it contains the unit clause .
Since contains the literal , this clause can be removed altogether. Since contains the negation of the literal in the unit clause, this literal can be removed from the clause. The unit clause is not removed; this would make the resulting set not equivalent to the original one; this clause can be removed if already stored in some other form (see section "Using a partial model"). The effect of unit propagation can be summarized as follows.
The resulting set of clauses is equivalent to the above one. The new unit claus
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https://en.wikipedia.org/wiki/Glide%20plane
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In geometry and crystallography, a glide plane (or transflection) is a symmetry operation describing how a reflection in a plane, followed by a translation parallel with that plane, may leave the crystal unchanged.
Glide planes are noted in the Hermann–Mauguin notation by a, b or c, depending on which axis the glide is along. (The orientation of the plane is determined by the position of the symbol in the Hermann–Mauguin designation.) If the axis is not defined, then the glide plane may be noted by g. When the glide plane is parallel to the screen, these planes may be indicated by a bent arrow in which the arrowhead indicates the direction of the glide. When the glide plane is perpendicular to the screen, these planes can be represented either by dashed lines when the glide is parallel to the plane of the screen or dotted lines when the glide is perpendicular to the plane of the screen. Additionally, a centered lattice can cause a glide plane to exist in two directions at the same time. This type of glide plane may be indicated by a bent arrow with an arrowhead on both sides when the glide plan is parallel to the plane of the screen or a dashed and double-dotted line when the glide plane is perpendicular to the plane of the screen. There is also the n glide, which is a glide along the half of a diagonal of a face, and the d glide, which is along a fourth of either a face or space diagonal of the unit cell . The latter is often called the diamond glide plane as it features in
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https://en.wikipedia.org/wiki/CTLA-4
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CTLA-4 or CTLA4 (cytotoxic T-lymphocyte-associated protein 4), also known as CD152 (cluster of differentiation 152), is a protein receptor that functions as an immune checkpoint and downregulates immune responses. CTLA-4 is constitutively expressed in regulatory T cells but only upregulated in conventional T cells after activation – a phenomenon which is particularly notable in cancers. It acts as an "off" switch when bound to CD80 or CD86 on the surface of antigen-presenting cells.
The CTLA-4 protein is encoded by the Ctla-4 gene in mice and the CTLA-4 gene in humans.
History
CTLA-4 was first identified in 1991 as a second receptor for the T cell costimulation ligand B7. In November 1995, the labs of Tak Wah Mak and Arlene H. Sharpe independently published their findings on the discovery of the function of CTLA-4 as a negative regulator of T-cell activation, by knocking out the gene in mice. Previous studies from several labs had used methods which could not definitively define the function of CTLA-4, and were contradictory.
Function
CTLA-4 is a member of the immunoglobulin superfamily that is expressed by activated T cells and transmits an inhibitory signal to T cells. CTLA-4 is homologous to the T-cell co-stimulatory protein, CD28, and both molecules bind to CD80 and CD86, also called B7-1 and B7-2 respectively, on antigen-presenting cells. CTLA-4 binds CD80 and CD86 with greater affinity and avidity than CD28 thus enabling it to outcompete CD28 for its ligands. CTLA
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https://en.wikipedia.org/wiki/Matrix%20Template%20Library
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The Matrix Template Library (MTL) is a linear algebra library for C++ programs.
The MTL uses template programming, which considerably reduces the code length. All matrices and vectors are available in all classical numerical formats: float, double, complex<float> or complex<double>.
Furthermore, generic programming allows the usage of arbitrary types as long as they provide the necessary operations. For instance one can use arbitrary integer formats (e.g. unsigned short), types for interval arithmetic (e.g. boost::interval) from the Boost C++ Libraries, quaternions (e.g. boost::quaternion), types of higher precision (e.g. GNU Multi-Precision Library) and appropriate user-defined types.
The MTL supports several implementations of dense matrices and sparse matrices. MTL2 has been developed by Jeremy Siek and Andrew Lumsdaine.
The latest version, MTL4, is developed by Peter Gottschling and Andrew Lumsdaine. It contains most of MTL2's functionality and adds new optimization techniques as meta-tuning, e.g. loop unrolling of dynamically sized containers can be specified in the function call. Platform-independent performance scalability is reached by recursive data structures and algorithms.
Generic applications can be written in a natural notation, e.g. v += A*q - w;, while the library dispatches to the appropriate algorithms: matrix vector products vs. matrix products vs. vector scalar products etcetera. The goal is to encapsulate performance issues inside the library and pro
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https://en.wikipedia.org/wiki/Laning%20and%20Zierler%20system
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The Laning and Zierler system (sometimes called "George" by its users) was the first operating algebraic compiler, that is, a system capable of accepting mathematical formulas in algebraic notation and producing equivalent machine code (the term compiler had not yet been invented and the system was referred to as "an interpretive program"). It was implemented in 1952 for the MIT WHIRLWIND by J. Halcombe Laning and Neal Zierler. It is preceded by non-algebraic compilers such as the UNIVAC A-0.
Description
The system accepted formulas in a more or less algebraic notation. It respected the standard rules for operator precedence, allowed nested parentheses, and used superscripts to indicate exponents. It was among the first programming systems to allow symbolic variable names and allocate storage automatically.
The system also automated the following tasks: floating point computation, linkage to subroutines for the basic functions of analysis (sine, etc.) and printing, and arrays and indexing.
The system accepted input on punched tape produced by a Friden Flexowriter. The character set in use at the Whirlwind installation included "upper-case" (superscript) digits and a hyphen, which were used to indicate array indices, function codes, and (integer) exponents. Like other programming notations of its time, the system accepted only single-letter variable names and multiplication was indicated by juxtaposition of operands. A raised dot was available to indicate multiplication exp
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https://en.wikipedia.org/wiki/GeoGebra
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GeoGebra (a portmanteau of geometry and algebra) is an interactive geometry, algebra, statistics and calculus application, intended for learning and teaching mathematics and science from primary school to university level. GeoGebra is available on multiple platforms, with apps for desktops (Windows, macOS and Linux), tablets (Android, iPad and Windows) and web. It is presently owned by Indian edutech firm Byju's.
History
GeoGebra's creator, Markus Hohenwarter, started the project in 2001 as part of his master's thesis at the University of Salzburg. After a successful Kickstarter campaign, GeoGebra expanded its offering to include an iPad, an Android and a Windows Store app version. In 2013, GeoGebra incorporated Xcas into its CAS view. The project is now freeware (with open-source portions) and multi-lingual, and Hohenwarter continues to lead its development at the University of Linz.
GeoGebra includes both commercial and not-for-profit entities that work together from the head office in Linz, Austria, to expand the software and cloud services available to users.
In December 2021, GeoGebra was acquired by edtech conglomerate Byju's for approximately $100 million USD.
Features
GeoGebra is an interactive mathematics software suite for learning and teaching science, technology, engineering, and mathematics from primary school up to the university level. Constructions can be made with points, vectors, segments, lines, polygons, conic sections, inequalities, implicit polynom
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https://en.wikipedia.org/wiki/Davis%E2%80%93Putnam%20algorithm
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The Davis–Putnam algorithm was developed by Martin Davis and Hilary Putnam for checking the validity of a first-order logic formula using a resolution-based decision procedure for propositional logic. Since the set of valid first-order formulas is recursively enumerable but not recursive, there exists no general algorithm to solve this problem. Therefore, the Davis–Putnam algorithm only terminates on valid formulas. Today, the term "Davis–Putnam algorithm" is often used synonymously with the resolution-based propositional decision procedure (Davis–Putnam procedure) that is actually only one of the steps of the original algorithm.
Overview
The procedure is based on Herbrand's theorem, which implies that an unsatisfiable formula has an unsatisfiable ground instance, and on the fact that a formula is valid if and only if its negation is unsatisfiable. Taken together, these facts imply that to prove the validity of φ it is enough to prove that a ground instance of ¬φ is unsatisfiable. If φ is not valid, then the search for an unsatisfiable ground instance will not terminate.
The procedure for checking validity of a formula φ roughly consists of these three parts:
put the formula ¬φ in prenex form and eliminate quantifiers
generate all propositional ground instances, one by one
check if each instance is satisfiable.
If some instance is unsatisfiable, then return that φ is valid. Else continue checking.
The last part is a SAT solver based on resolution (as seen on the ill
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https://en.wikipedia.org/wiki/Cantor%27s%20paradox
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In set theory, Cantor's paradox states that there is no set of all cardinalities. This is derived from the theorem that there is no greatest cardinal number. In informal terms, the paradox is that the collection of all possible "infinite sizes" is not only infinite, but so infinitely large that its own infinite size cannot be any of the infinite sizes in the collection. The difficulty is handled in axiomatic set theory by declaring that this collection is not a set but a proper class; in von Neumann–Bernays–Gödel set theory it follows from this and the axiom of limitation of size that this proper class must be in bijection with the class of all sets. Thus, not only are there infinitely many infinities, but this infinity is larger than any of the infinities it enumerates.
This paradox is named for Georg Cantor, who is often credited with first identifying it in 1899 (or between 1895 and 1897). Like a number of "paradoxes" it is not actually contradictory but merely indicative of a mistaken intuition, in this case about the nature of infinity and the notion of a set. Put another way, it is paradoxical within the confines of naïve set theory and therefore demonstrates that a careless axiomatization of this theory is inconsistent.
Statements and proofs
In order to state the paradox it is necessary to understand that the cardinal numbers are totally ordered, so that one can speak about one being greater or less than another. Then Cantor's paradox is:
This fact is a direct conse
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https://en.wikipedia.org/wiki/Boole%27s%20expansion%20theorem
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Boole's expansion theorem, often referred to as the Shannon expansion or decomposition, is the identity: , where is any Boolean function, is a variable, is the complement of , and and are with the argument set equal to and to respectively.
The terms and are sometimes called the positive and negative Shannon cofactors, respectively, of with respect to . These are functions, computed by restrict operator, and (see valuation (logic) and partial application).
It has been called the "fundamental theorem of Boolean algebra". Besides its theoretical importance, it paved the way for binary decision diagrams (BDDs), satisfiability solvers, and many other techniques relevant to computer engineering and formal verification of digital circuits.
In such engineering contexts (especially in BDDs), the expansion is interpreted as a if-then-else, with the variable being the condition and the cofactors being the branches ( when is true and respectively when is false).
Statement of the theorem
A more explicit way of stating the theorem is:
Variations and implications
XOR-Form The statement also holds when the disjunction "+" is replaced by the XOR operator:
Dual form There is a dual form of the Shannon expansion (which does not have a related XOR form):
Repeated application for each argument leads to the Sum of Products (SoP) canonical form of the Boolean function . For example for that would be
Likewise, application of the dual form leads to the Product of Sums
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https://en.wikipedia.org/wiki/Mires%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the mire plant communities in the British National Vegetation Classification system.
Introduction
The mire communities of the NVC were described in Volume 2 of British Plant Communities, first published in 1991, along with the heath communities.
In total, 38 mire communities have been identified.
The mire communities consist of a number of separate subgroups.
five bog plane communities (M17, M18, M19, M20 and M21)
two wet heath communities (M15 and M16)
four bog-pool communities (M1, M2, M3 and M4)
four base-poor small sedge & rush communities (M5, M6, M7 and M8)
six base-poor small sedge & Schoenus communities (M9, M10, M11, M12, M13 and M14)
seven fen-meadow / rush-pasture communities (M22, M23, M24, M25, M26, M27 and M28)
two soakaway communities (M29 and M30)
eight communities of springs and rills (M31, M32, M33, M34, M35, M36, M37 and M38)
List of mire communities
The following is a list of the communities that make up this category:
M1 Sphagnum auriculatum bog pool community
M2 Sphagnum cuspidatum/recurvum bog pool community
M3 Eriophorum angustifolium bog pool community
M4 Carex rostrata - Sphagnum recurvum mire
M5 Carex rostrata - Sphagnum squarrosum mire
M6 Carex echinata - Sphagnum recurva/auriculatum mire
M7 Carex curta - Sphagnum russowii mire
M8 Carex rostrata - Sphagnum warnstorfii mire
M9 Carex rostrata - Calligeron cuspidatum/giganteum mire
M10 Carex dioica - Pinguicula vulgaris mire Pinguiculo-Carice
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https://en.wikipedia.org/wiki/Heaths%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the heath communities in the British National Vegetation Classification system.
Introduction
The heath communities of the NVC were described, along with the mire communities, in Volume 2 of British Plant Communities, first published in 1991.
In total, 22 heath communities have been identified.
The heath communities consist of six separate subgroups:
five lowland dry heath communities, all with distinct, largely non-overlapping distributions in England and Wales (H1, H2, H6, H8 and H9)
three localised communities, with non-overlapping ranges in southern England, which are considered transitional between the above and the wetter communities classified in the NVC as mires (H3, H4 and H5)
two maritime heath communities, found exclusively on the coasts of northern and western Britain; one (H7) is more widespread than the other (H11)
four submontane heaths from upland areas in northern and western Britain; two of these (H10 and H12) are widespread, whereas the other two (H16 and H21) are more localised (confined to Scotland, and Scotland and the Lake District, respectively)
two sub-alpine communities, considered transitional between the previous and next groupings - H18, which is widespread in northern and western Britain), and H22, which is confined to Scotland
six montane heath communities with lichens and mosses, all of which are confined either to Scotland (H13, H14, H15, H17 and H20) or to Scotland and the Lake District (H19)
List o
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https://en.wikipedia.org/wiki/Mesotrophic%20grasslands%20in%20the%20British%20National%20Vegetation%20Classification%20system
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The mesotrophic grassland communities in the British National Vegetation Classification system were described in Volume 3 of British Plant Communities, first published in 1992, along with the calcicolous grassland communities and the calcifugous grasslands and montane communities.
In total, 13 mesotrophic grassland communities have been identified:
two communities in which False Oat-grass is the characteristic grass species (one of these, community MG1, is widespread throughout Britain; the other, MG2, is confined to northern England).
four communities of well-drained permanent pastures and meadows, two of which (MG5 and MG6) are widespread and the other two (MG3 and MG4) more localised
a single community (MG7) covering a variety of widespread types of Perennial Rye-grass long-term ley
three widespread communities associated with poorly drained permanent pastures (MG8, MG9, MG10)
three grass-dominated inundation communities, one of which, MG13, is widespread, the other two, MG11 and MG12, more localised
List of mesotrophic grassland communities
The following is a list of the communities that make up this category:
MG1 Arrhenatherum elatius grassland Arrhenatheretum elatioris Br.-Bl. 1919
MG2 Arrhenatherum elatius - Filipendula ulmaria tall-herb grassland Filipendulo-Arrhenatheretum elatioris Shimwell 1968a
MG3 Anthoxanthum odoratum - Geranium sylvaticum grassland
MG4 Alopecurus pratensis - Sanguisorba officinalis grassland
MG5 Cynosurus cristatus - Centaurea ni
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https://en.wikipedia.org/wiki/Calcicolous%20grasslands%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the calcicolous grassland communities in the British National Vegetation Classification system.
Introduction
The calcicolous grassland communities of the NVC were described in Volume 3 of British Plant Communities, first published in 1992, along with the mesotrophic grassland communities and the calcifugous grasslands and montane communities.
In total, 14 calcicolous grassland communities have been identified.
All but two of the calcicolous grassland communities fall into two broad groups:
seven communities which group loosely together under an umbrella of "chalk grassland" and which are found on calcareous soils in the comparatively dry climatic conditions of the lowlands of southern and eastern England (and also in northern and southern coastal areas of Wales).
five upland calcicole communities, distributed in areas of wetter climate through the uplands of Wales, northern England and Scotland.
The lowlands group comprises two subgroups:
three short-sward communities associated with heavy grazing: a widespread community (CG2) that is regarded as "typical" chalk grassland, though it also occurs widely on limestone, and its "south-west coastal" (CG1) and "eastern" (CG7) counterparts
four communities of rank, tussocky grassland associated with low levels of grazing (CG3, CG4, CG5 and CG6)
The upland group comprises the following subgroups:
a widespread short-sward community associated with heavy grazing, CG10
two localised commun
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https://en.wikipedia.org/wiki/Calcifugous%20grasslands%20and%20montane%20communities%20in%20the%20British%20National%20Vegetation%20Classification%20system
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Calcifugous grasslands and montane communities are botanical groupings in the British National Vegetation Classification system.
The calcifugous grasslands and montane communities of the NVC were described in Volume 3 of British Plant Communities, first published in 1992, along with the mesotrophic grassland communities and the calcicolous grassland communities.
In total, 21 calcifugous grasslands and montane communities have been identified.
The calcifugous grasslands and montane communities consist of the following groupings:
five grass-dominated communities which group together as "sub-montane calcifugous grasslands"; two of these, U1 and U2 are found throughout Britain, two more U4 and U5 are found throughout upland areas of Scotland, Wales and northern and western England, and one, U3, is localised in southwest England.
a sixth submontane community, U6, dominated by Heath Rush Juncus squarrosus
four communities categorised as "calcifugous vegetation of low- and middle-alpine snow-fields", all of which are confined or nearly confined to Scotland: U7, U8, U11 and U12
two moss- and rush-heaths of low- and middle-alpine plateaus U10, which is confined to Scotland, and U9 which is also found in northern England and North Wales
five communities grouped together as "mesotrophic montane swards and herb-rich banks and ledges": U13, U14, U15, U16 and U17; some of these are confined to Scotland while others extend into northern England or North Wales
four calcifuge fern c
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https://en.wikipedia.org/wiki/Aquatic%20communities%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the aquatic communities in the British National Vegetation Classification system.
Introduction
The aquatic communities of the NVC were described in Volume 4 of British Plant Communities, first published in 1995, along with the swamps and tall-herb fens.
In total, 24 aquatic communities have been identified.
The aquatic communities fall into the following six groups:
four communities of the water surface and sub-surface, in which duckweeds and/or Frogbit are the constant species; these communities (A1, A2, A3 and A4) are found in moderately-rich to eutrophic standing waters
eight free-floating or rooted and submerged, pondweed communities (A5, A6, A11, A12, A13, A14, A15 and A21)
six communities in which rooted water-lilies and pondweeds with floating leaves are the constant species (A7, A8, A9, A10, A19 and A20)
three communities in which water-crowfoots and/or starworts are the constant species (A16, A17 and A18)
two hairgrass and quillwort communities (A22 and A23)
a single community characterised by free-floating vegetation found in impoverished base-poor standing waters (A24).
List of aquatic communities
The following is a list of the communities that make up this category:
A1 Lemna gibba community Lemnetum gibbae Miyawaki & J. Tx. 1960
A2 Lemna minor community Lemnetum minoris Soó 1947
A3 Spirodela polyrhiza - Hydrocharis morsus-ranae community
A4 Hydrocharis morsus-ranae - Stratiotes aloides community
A5 Ceratophyllum d
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https://en.wikipedia.org/wiki/Swamps%20and%20tall-herb%20fens%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the swamp and tall-herb fen communities in the British National Vegetation Classification system.
Introduction
The swamp and tall-herb fen communities of the NVC were described in Volume 4 of British Plant Communities, first published in 1995, along with the aquatic communities.
In total, 28 swamp and tall-herb fen communities have been identified.
The swamp and tall-herb fen communities consist of three separate subgroups:
twenty-one swamp communities, characterised by being species-poor, each dominated by an often tall or bulky monocotyledon species, with little or nothing in the way of an understorey: S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, S14, S15, S16, S17, S18, S19, S20 and S29
two communities termed "water-margin vegetation": S22 and S23
five tall-herb fen communities, which have a more species-rich understorey than the swamps: S24, S25, S26, S27 and S28
List of swamp and tall-herb fen communities
The following is a list of the communities that make up this category:
S1 Carex elata sedge-swamp Caricetum elatae Koch 1926
S2 Cladium mariscus swamp and sedge-beds Cladietum marisci Zobrist 1933 emend. Pfeiffer 1961
S3 Carex paniculata swamp Caricetum paniculatae Wangerin 1916
S4 Phragmites australis swamp and reed-beds Phragmitetum australis (Gams 1927) Schmale 1939
S5 Glyceria maxima swamp Glycerietum maximae (Nowinski 1928) Hueck 1931 emend. Krausch 1965
S6 Carex riparia swamp Caricetum ripariae Soó 1928
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https://en.wikipedia.org/wiki/Salt-marsh%20communities%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the salt-marsh communities in the British National Vegetation Classification system.
Introduction
The salt-marsh communities of the NVC were described in Volume 5 of British Plant Communities, first published in 2000, along with the other maritime communities (those of shingle strandline and sand-dunes and maritime cliffs) and vegetation of open habitats.
In total, 28 salt-marsh communities have been identified.
The salt-marsh communities consist of four separate subgroups:
three eel-grass and tassel-weed communities of tidal flats, pools and ditches (SM1, SM2 and SM3)
thirteen communities of the lower salt-marsh (SM4, SM5, SM6, SM7, SM8, SM9, SM10, SM11, SM12, SM13, SM14, SM15 and SM26)
nine communities of the middle salt-marsh (SM16, SM17, SM18, SM19, SM20, SM21, SM22, SM23 and SM27)
three communities of the upper salt-marsh (SM24, SM25 and SM28)
Other communities occurring on salt-marshes
There are a number of other communities which occur on salt-marshes, but are not classified as salt-marsh communities within the NVC. Those listed in British Plant Communities are as follows:
List of salt-marsh communities
The following is a list of the communities that make up this category:
SM1 Zostera communities Zosterion Christiansen 1934
SM2 Ruppia maritima salt-marsh community Ruppietum maritimae Hocquette 1927
SM3 Eleocharis parvula salt-marsh community Eleocharitetum parvulae (Preuss 1911/12) Gillner 1960
SM4 Spartina maritima sa
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https://en.wikipedia.org/wiki/Shingle%2C%20strandline%20and%20sand-dune%20communities%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the shingle, strandline and sand-dune communities in the British National Vegetation Classification system.
Introduction
The shingle, strandline and sand-dune communities of the NVC were described in Volume 5 of British Plant Communities, first published in 2000, along with the other maritime communities (those of saltmarshes and maritime cliffs) and vegetation of open habitats.
In total, 19 shingle, strandline and sand-dune communities have been identified.
The shingle, strandline and sand-dune communities consist of a single community found on coastal shingle (SD1), two communities associated with strandlines (SD2 and SD3), and sixteen sand-dune communities.
The sand-dune communities fall into the following four groups:
six foredune and mobile dune communities (SD4, SD5, SD6, SD7, SD10 and SD19)
four fixed-dune grasslands (SD8, SD9, SD11 and SD12)
five dune-slack communities (SD13, SD14, SD15, SD16 and SD17)
one dune scrub community, SD18
Other communities occurring on sand-dunes
There are a number of other communities which occur on sand-dunes, but are not classified as sand-dune communities within the NVC. Those listed in British Plant Communities are as follows:
Maritime cliff communities MC5 and MC6
Open vegetation communities OV4 and OV27
Mesotrophic grassland communities MG8, MG10 and MG11
Swamp communities S4 and S19
Mire communities M15 and M16
Heath community H11
List of shingle, strandline and sand-dune communit
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https://en.wikipedia.org/wiki/Maritime%20cliff%20communities%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the maritime cliff communities in the British National Vegetation Classification system.
Introduction
The maritime cliff communities of the NVC were described in Volume 5 of British Plant Communities, first published in 2000, along with the other maritime communities (those of shingle strand-line and sand-dunes and saltmarshes) and vegetation of open habitats.
In total, 12 maritime cliff communities have been identified.
The maritime cliff communities consist of three subgroups:
five maritime cliff crevice and ledge communities (MC1, MC2, MC3, MC4 and MC5)
five maritime grassland communities of sea-cliffs (MC8, MC9, MC10, MC11 and MC12)
two communities associated with sea-bird cliffs (MC6 and MC7)
List of maritime cliff communities
The following is a list of the communities that make up this category:
MC1 Crithmum maritimum - Spergularia rupicola maritime rock-crevice community Crithmo-Spergularietum rupicolae Géhu 1964
MC2 Armeria maritima - Ligusticum scoticum maritime rock-crevice community
MC3 Rhodiola rosea - Armeria maritima maritime cliff-ledge community
MC4 Brassica oleracea maritime cliff-ledge community
MC5 Armeria maritima - Cerastium diffusum ssp. diffusum maritime therophyte community
MC6 Atriplex prostrata - Beta vulgaris ssp. maritima sea-bird cliff community Atriplici-Betetum maritimae J.-M. & J. Géhu 1969
MC7 Stellaria media - Rumex acetosa sea-bird cliff community
MC8 Festuca rubra - Armeria maritima marit
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https://en.wikipedia.org/wiki/Vegetation%20of%20open%20habitats%20in%20the%20British%20National%20Vegetation%20Classification%20system
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This article gives an overview of the plant communities formed by vegetation of open habitats in the British National Vegetation Classification system.
Introduction
The open habitat communities of the NVC were described in Volume 5 of British Plant Communities, first published in 2000, along with the three groups of maritime communities (shingle, strandline and sand-dune communities, salt-marsh communities and maritime cliff communities).
In total, 42 open habitat communities have been identified.
The open habitat communities consist of eight distinct subgroups:
six arable weed and trackside communities of light, less-fertile acid soils (OV1, OV2, OV3, OV4, OV5 and OV6)
eight arable weed and wasteland communities of fertile loams and clays (OV7, OV8, OV9, OV10, OV11, OV12, OV13 and OV14)
three arable weed communities of light, limey soils (OV15, OV16 and OV17)
six gateway, trackside and courtyard communities (OV18, OV19, OV20, OV21, OV22 and OV23)
four tall-herb weed communities (OV24, OV25, OV26 and OV27)
five communities typical of periodically inundated habitats (OV28, OV29, OV30, OV32 and OV33)
four dwarf-rush communities of ephemeral ponds (OV31, OV34, OV35 and OV36)
six communities of crevice, scree and spoil vegetation (OV37, OV38, OV39, OV40, OV41 and OV42)
List of open habitat communities
The following is a list of the communities that make up this category:
OV1 Viola arvensis - Aphanes microcarpa community
OV2 Briza minor - Silene gallica communit
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https://en.wikipedia.org/wiki/Perilymph
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Perilymph is an extracellular fluid located within the inner ear. It is found within the scala tympani and scala vestibuli of the cochlea. The ionic composition of perilymph is comparable to that of plasma and cerebrospinal fluid. The major cation in perilymph is sodium, with the values of sodium and potassium concentration in the perilymph being 138 mM and 6.9 mM, respectively. It is also named Cotunnius' liquid and liquor cotunnii for Domenico Cotugno.
Structure
The inner ear has two major parts, the cochlea and the vestibular organ. They are connected in a series of canals in the temporal bone referred to as the bony labyrinth. The bone canals are separated by the membranes in parallel spaces referred to as the membranous labyrinth. The membranous labyrinth contains endolymph, and is surrounded by perilymph. The perilymph in the bony labyrinth serves as connection to the cerebrospinal fluid of the subarachnoid space via the perilymphatic duct.
Composition
Perilymph and endolymph have unique ionic compositions suited to their functions in regulating electrochemical impulses of hair cells necessary for hearing. The electric potential of endolymph is ~80-90 mV more positive than perilymph due to a higher concentration of potassium cations (K+) in endolymph and higher sodium (Na+) in perilymph. This is referred to as the endocochlear potential.
Perilymph is the fluid contained within the bony labyrinth, surrounding and protecting the membranous labyrinth; perilymph resembl
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https://en.wikipedia.org/wiki/Alphavirus
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Alphavirus is a genus of RNA viruses, the sole genus in the Togaviridae family. Alphaviruses belong to group IV of the Baltimore classification of viruses, with a positive-sense, single-stranded RNA genome. There are 32 alphaviruses, which infect various vertebrates such as humans, rodents, fish, birds, and larger mammals such as horses, as well as invertebrates. Alphaviruses that could infect both vertebrates and arthropods are referred dual-host alphaviruses, while insect-specific alphaviruses such as Eilat virus and Yada yada virus are restricted to their competent arthropod vector. Transmission between species and individuals occurs mainly via mosquitoes, making the alphaviruses a member of the collection of arboviruses – or arthropod-borne viruses. Alphavirus particles are enveloped, have a 70 nm diameter, tend to be spherical (although slightly pleomorphic), and have a 40 nm isometric nucleocapsid.
Genome
The alphaviruses are small, spherical, enveloped viruses with a genome of a single strand of positive-sense RNA. The total genome length ranges between 11,000 and 12,000 nucleotides, and has a 5’ cap and a 3’ poly-A tail. The four non-structural protein genes are encoded in the 5′ two-thirds of the genome, while the three structural proteins are translated from a subgenomic mRNA colinear with the 3′ one-third of the genome.
There are two open reading frames (ORFs) in the genome, nonstructural and structural. The first is non-structural and encodes proteins (nsP1–nsP
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https://en.wikipedia.org/wiki/Fr%C3%A9chet%20derivative
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In mathematics, the Fréchet derivative is a derivative defined on normed spaces. Named after Maurice Fréchet, it is commonly used to generalize the derivative of a real-valued function of a single real variable to the case of a vector-valued function of multiple real variables, and to define the functional derivative used widely in the calculus of variations.
Generally, it extends the idea of the derivative from real-valued functions of one real variable to functions on normed spaces. The Fréchet derivative should be contrasted to the more general Gateaux derivative which is a generalization of the classical directional derivative.
The Fréchet derivative has applications to nonlinear problems throughout mathematical analysis and physical sciences, particularly to the calculus of variations and much of nonlinear analysis and nonlinear functional analysis.
Definition
Let and be normed vector spaces, and be an open subset of A function is called Fréchet differentiable at if there exists a bounded linear operator such that
The limit here is meant in the usual sense of a limit of a function defined on a metric space (see Functions on metric spaces), using and as the two metric spaces, and the above expression as the function of argument in As a consequence, it must exist for all sequences of non-zero elements of that converge to the zero vector Equivalently, the first-order expansion holds, in Landau notation
If there exists such an operator it is unique, so
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https://en.wikipedia.org/wiki/Psychographics
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Psychographics is defined as "market research or statistics classifying population groups according to psychological variables" The term psychographics is derived from the words “psychological” and “demographics” Two common approaches to psychographics include analysis of consumers' activities, interests, and opinions (AIO variables), and values and lifestyles (VALS).
Psychographics have been applied to the study of personality, values, opinions, attitudes, interests, and lifestyles. Psychographic segmentation is a technique for grouping populations into sub-groups according to similar psychological variables.
Psychographic studies of individuals or communities can be valuable in the fields of marketing, demographics, opinion research, prediction, and social research in general. Psychographic attributes can be contrasted with demographic variables (such as age and gender), behavioral variables (such as purchase data or usage rate), and organizational descriptors (sometimes called firmographic variables), such as industry, number of employees, and functional area.
Psychographic methods gained prominence in the 2016 US presidential election and the opposing campaigns of Hillary Clinton and Donald Trump, with the latter using them extensively in microtargeting advertisements to narrow constituencies.
Uses
Psychographics is utilized in the field of marketing and advertising to understand the preferences of consumers and to predict behavior. Private research companies cond
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https://en.wikipedia.org/wiki/KDXL
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KDXL (106.5 FM) was a student operated radio station at St. Louis Park High School in St. Louis Park, Minnesota. The station's frequency was 106.5, which it shared with the University of Minnesota's KUOM-FM in a timesharing agreement. The station was owned by Independent School District #283.
History
The station began in 1973 with a low-power signal that could only reach a portion of St. Louis Park High School; during this period, the station used the call signs WHAT, WSLP, and KTS. In 1977, the Federal Communications Commission (FCC) granted the school district a license to operate a 10-watt radio station, which took the call sign KDXL. KDXL operated at 91.7 through 1985; it changed frequencies so that it would not have a frequency close to KQRS-FM.
Independent School District #283 voted to shut down KDXL on June 25, 2018; the following day, it informed the FCC that the station would cease operations on July 1. The license was cancelled on July 16, 2018.
References
External links
Radio stations in Minnesota
Radio stations established in 1977
1977 establishments in Minnesota
Radio stations disestablished in 2018
2018 disestablishments in Minnesota
Defunct radio stations in the United States
Defunct mass media in Minnesota
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https://en.wikipedia.org/wiki/Dancing%20Links
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In computer science, dancing links (DLX) is a technique for adding and deleting a node from a circular doubly linked list. It is particularly useful for efficiently implementing backtracking algorithms, such as Knuth's Algorithm X for the exact cover problem. Algorithm X is a recursive, nondeterministic, depth-first, backtracking algorithm that finds all solutions to the exact cover problem. Some of the better-known exact cover problems include tiling, the n queens problem, and Sudoku.
The name dancing links, which was suggested by Donald Knuth, stems from the way the algorithm works, as iterations of the algorithm cause the links to "dance" with partner links so as to resemble an "exquisitely choreographed dance." Knuth credits Hiroshi Hitotsumatsu and Kōhei Noshita with having invented the idea in 1979, but it is his paper which has popularized it.
Implementation
As the remainder of this article discusses the details of an implementation technique for Algorithm X, the reader is strongly encouraged to read the Algorithm X article first.
Main ideas
The idea of DLX is based on the observation that in a circular doubly linked list of nodes,
x.left.right ← x.right;
x.right.left ← x.left;
will remove node x from the list, while
x.left.right ← x;
x.right.left ← x;
will restore x'''s position in the list, assuming that x.right and x.left have been left unmodified. This works regardless of the number of elements in the list, even if that number is 1.
Knuth observed that
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https://en.wikipedia.org/wiki/Bangstad%20syndrome
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Bangstad syndrome is a severe, inherited congenital disorder associated with abnormalities of the cell membrane.
It was characterized in 1989 by H. J. Bangstad.
Presentation
Presenting at birth, features of the disorder include moderately severe IUGR, microcephaly, craniosynostosis, moderately severe post-uterine growth retardation, deafness, deep-set eyes, cryptorchidism, truncal obesity and acanthosis nigricans, small teeth, prognathism, dislocated radial heads without generalized skeletal dysplasia, however, tall vertebrae, moderate mental retardation, hypothyroidism, insulin resistance, hypoparathyroidism.
Diagnosis
Treatment
References
External links
Congenital disorders
Genetic disorders with OMIM but no gene
Syndromes affecting head size
Syndromes affecting hearing
Diseases named for discoverer
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https://en.wikipedia.org/wiki/Switch%20London
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Switch London is a DAB ensemble operated by Switchdigital; it broadcasts from a variety of sites in and around London (Alexandra Palace, Arkley, Bluebell Hill, BT Tower, Colindale House, Crystal Palace, Guildford, Hampstead, Harrow Weald, Hemel Hempstead, Leatherhead Stoke d'Abernon, Mount Vernon, Otford, Reigate, Richmond Hill, Shepherds Bush, Shooters Hill, Sidcup, Staines, Uxbridge and Zouches Farm). It has been on air since July 2000. It is also referred to as the Greater London 2 multiplex. In their application to the Radio Authority, Switch proposed using Brookmans Park as a transmission site in its SFN, but this has not yet been implemented.
In 2010, the Otford relay site was replaced by the much more powerful Wrotham site in Kent which broadcasts at 5 kW.
Stations carried
References
See also
DRG London
CE London
Radio stations in London
Digital audio broadcasting multiplexes
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https://en.wikipedia.org/wiki/International%20Patent%20Classification
|
The International Patent Classification (IPC) is a hierarchical patent classification system used in over 100 countries to classify the content of patents in a uniform manner. It was created under the Strasbourg Agreement (1971), one of a number of treaties administered by the World Intellectual Property Organization (WIPO). The classification is updated on a regular basis by a Committee of Experts, consisting of representatives of the Contracting States of that Agreement with observers from other organisations, such as the European Patent Office.
Classification
Patent publications from all of the Contracting States (and also most others) are each assigned at least one classification symbol indicating the subject to which the invention relates and may also be assigned further classification symbols and indexing codes to give further details of the contents.
Each classification symbol is of the form A01B 1/00 (which represents "hand tools"). The first letter represents the "section" consisting of a letter from A ("Human Necessities") to H ("Electricity"). Combined with a two digit number, it represents the "class" (class A01 represents "Agriculture; forestry; animal husbandry; trapping; fishing"). The final letter makes up the "subclass" (subclass A01B represents "Soil working in agriculture or forestry; parts, details, or accessories of agricultural machines or implements, in general"). The subclass is followed by a one-to-three-digit "group" number, an oblique stroke and a
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https://en.wikipedia.org/wiki/Bicorn
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In geometry, the bicorn, also known as a cocked hat curve due to its resemblance to a bicorne, is a rational quartic curve defined by the equation
It has two cusps and is symmetric about the y-axis.
History
In 1864, James Joseph Sylvester studied the curve
in connection with the classification of quintic equations; he named the curve a bicorn because it has two cusps. This curve was further studied by Arthur Cayley in 1867.
Properties
The bicorn is a plane algebraic curve of degree four and genus zero. It has two cusp singularities in the real plane, and a double point in the complex projective plane at x=0, z=0. If we move x=0 and z=0 to the origin substituting and perform an imaginary rotation on x bu substituting ix/z for x and 1/z for y in the bicorn curve, we obtain
This curve, a limaçon, has an ordinary double point at the origin, and two nodes in the complex plane, at and .
The parametric equations of a bicorn curve are and with .
See also
List of curves
References
External links
Plane curves
Algebraic curves
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https://en.wikipedia.org/wiki/Rediffusion%20Television
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Rediffusion Television (RTV) was the first television station in Hong Kong, making it both the first British colony and the first predominantly ethnically Chinese city to have television. It began as a radio station in 1949 and became Asia Television on 24 September 1982.
History
Radio Rediffusion was officially founded in 1949 as a highly successful wired radio station run by the Rediffusion company. The radio service was highly successful with its main competitor Commercial Radio. Some of the early contents included plays, stories, concerts and Cantonese operas. The broadcasts were some of the main attraction in Hong Kong tea shops. One of the most famous broadcasters was Li Ngaw: another was Uncle Ray, the pioneering DJ.
It later became a subscription cable television station on 29 May 1957, becoming the first television station in a colony of the British Empire, as well as the first television station in a predominantly Chinese city. It initially offered a four-hour-per-day English language and Chinese language service. The installation fee during its launch was HK$25, with an equipment rental fee of $45, and a monthly subscription charge of $36.
The charge was considered expensive, at a time when the average worker in Hong Kong earned HK$100 per month. Hong Kong tea shops once again provided an outlet for the broadcasts to the working class who could not afford the subscription fees.
When competitor TVB made its first free-to-air broadcast on 19 November 1967, RTV h
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https://en.wikipedia.org/wiki/Bullet-nose%20curve
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In mathematics, a bullet-nose curve is a unicursal quartic curve with three inflection points, given by the equation
The bullet curve has three double points in the real projective plane, at and , and , and and , and is therefore a unicursal (rational) curve of genus zero.
If
then
are the two branches of the bullet curve at the origin.
References
Plane curves
Algebraic curves
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https://en.wikipedia.org/wiki/Cochleoid
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In geometry, a cochleoid is a snail-shaped curve similar to a strophoid which can be represented by the polar equation
the Cartesian equation
or the parametric equations
The cochleoid is the inverse curve of Hippias' quadratrix.
Notes
References
Cochleoid in the Encyclopedia of Mathematics
Liliana Luca, Iulian Popescu: A Special Spiral: The Cochleoid. Fiabilitate si Durabilitate - Fiability & Durability no 1(7)/ 2011, Editura "Academica Brâncuşi" , Târgu Jiu,
Roscoe Woods: The Cochlioid. The American Mathematical Monthly, Vol. 31, No. 5 (May, 1924), pp. 222–227 (JSTOR)
Howard Eves: A Graphometer. The Mathematics Teacher, Vol. 41, No. 7 (November 1948), pp. 311-313 (JSTOR)
External links
cochleoid at 2dcurves.com
Plane curves
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https://en.wikipedia.org/wiki/Folium%20of%20Descartes
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In geometry, the folium of Descartes (; named for René Descartes) is an algebraic curve defined by the implicit equation
History
The curve was first proposed and studied by René Descartes in 1638. Its claim to fame lies in an incident in the development of calculus. Descartes challenged Pierre de Fermat to find the tangent line to the curve at an arbitrary point since Fermat had recently discovered a method for finding tangent lines. Fermat solved the problem easily, something Descartes was unable to do. Since the invention of calculus, the slope of the tangent line can be found easily using implicit differentiation.
Graphing the curve
The folium of Descartes can be expressed in polar coordinates as
which is plotted on the left. This is equivalent to
Another technique is to write and solve for and in terms of . This yields the rational parametric equations:
.
We can see that the parameter is related to the position on the curve as follows:
corresponds to , : the right, lower, "wing".
corresponds to , : the left, upper "wing".
corresponds to , : the loop of the curve.
Another way of plotting the function can be derived from symmetry over . The symmetry can be seen directly from its equation (x and y can be interchanged). By applying rotation of 45° CW for example, one can plot the function symmetric over rotated x axis.
This operation is equivalent to a substitution:
and yields
Plotting in the Cartesian system of gives the folium rotated by 45° and ther
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https://en.wikipedia.org/wiki/Hippopede
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In geometry, a hippopede () is a plane curve determined by an equation of the form
where it is assumed that and since the remaining cases either reduce to a single point or can be put into the given form with a rotation. Hippopedes are bicircular, rational, algebraic curves of degree 4 and symmetric with respect to both the and axes.
Special cases
When d > 0 the curve has an oval form and is often known as an oval of Booth, and when the curve resembles a sideways figure eight, or lemniscate, and is often known as a lemniscate of Booth, after 19th-century mathematician James Booth who studied them. Hippopedes were also investigated by Proclus (for whom they are sometimes called Hippopedes of Proclus) and Eudoxus. For , the hippopede corresponds to the lemniscate of Bernoulli.
Definition as spiric sections
Hippopedes can be defined as the curve formed by the intersection of a torus and a plane, where the plane is parallel to the axis of the torus and tangent to it on the interior circle. Thus it is a spiric section which in turn is a type of toric section.
If a circle with radius a is rotated about an axis at distance b from its center, then the equation of the resulting hippopede in polar coordinates
or in Cartesian coordinates
.
Note that when a > b the torus intersects itself, so it does not resemble the usual picture of a torus.
See also
List of curves
References
Lawrence JD. (1972) Catalog of Special Plane Curves, Dover Publications. Pp. 145–146.
Booth J.
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https://en.wikipedia.org/wiki/Kampyle%20of%20Eudoxus
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The Kampyle of Eudoxus (Greek: καμπύλη [γραμμή], meaning simply "curved [line], curve") is a curve with a Cartesian equation of
from which the solution x = y = 0 is excluded.
Alternative parameterizations
In polar coordinates, the Kampyle has the equation
Equivalently, it has a parametric representation as
History
This quartic curve was studied by the Greek astronomer and mathematician Eudoxus of Cnidus (c. 408 BC – c.347 BC) in relation to the classical problem of doubling the cube.
Properties
The Kampyle is symmetric about both the x- and y-axes. It crosses the x-axis at (±a,0). It has inflection points at
(four inflections, one in each quadrant). The top half of the curve is asymptotic to as , and in fact can be written as
where
is the th Catalan number.
See also
List of curves
References
External links
Plane curves
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https://en.wikipedia.org/wiki/Serpentine%20curve
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A serpentine curve is a curve whose equation is of the form
Equivalently, it has a parametric representation
,
or functional representation
The curve has an inflection point at the origin. It has local extrema at , with a maximum value of and a minimum value of .
History
Serpentine curves were studied by L'Hôpital and Huygens, and named and classified by Newton.
Visual appearance
External links
MathWorld – Serpentine Equation
Cubic curves
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https://en.wikipedia.org/wiki/Coherence%20bandwidth
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Coherence bandwidth is a statistical measurement of the range of frequencies over which the channel can be considered "flat", or in other words the approximate maximum bandwidth or frequency interval over which two frequencies of a signal are likely to experience comparable or correlated amplitude fading. If the multipath time delay spread equals D seconds, then the coherence bandwidth in rad/s is given approximately by the equation:
Also coherence bandwidth in Hz is given approximately by the equation:
It can be reasonably assumed that the channel is flat if the coherence bandwidth is greater than the data signal bandwidth.
The coherence bandwidth varies over cellular or PCS communications paths because the multipath spread D varies from path to path.
Application
Frequencies within a coherence bandwidth of one another tend to all fade in a similar or correlated fashion. One reason for designing the CDMA IS-95 waveform with a bandwidth of approximately 1.25 MHz is because in many urban signaling environments the coherence bandwidth Bc is significantly less than 1.25 MHz. Therefore, when fading occurs it occurs only over a relatively small fraction of the total CDMA signal bandwidth. The portion of the signal bandwidth over which fading does not occur typically contains enough signal power to sustain reliable communications. This is the bandwidth over which the channel transfer function remains virtually constant.
Example
If the delay spread D over a particular cellular
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https://en.wikipedia.org/wiki/Tandemly%20arrayed%20genes
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Tandemly arrayed genes (TAGs) are a gene cluster created by tandem duplications, a process in which one gene is duplicated and the copy is found adjacent to the original. They serve to encode large numbers of genes at a time.
TAGs represent a large proportion of genes in a genome, including between 14% and 17% of the human, mouse, and rat genomes. TAG clusters may have as few as two genes, with small clusters predominating, but may consist of hundreds of genes. An example are tandem clusters of rRNA encoding genes. These genes are transcribed faster than they would be if only a single copy of the gene was available. Additionally, a single RNA gene may not be able to provide enough RNA, but tandem repeats of the gene allow sufficient RNA to be produced. For example, cells in a human embryo contain between five and ten million ribosomes, and cell number doubles within 24 hours. In order to provide the necessary ribosomes, multiple RNA polymerases must consecutively transcribe multiple rRNA genes.
In some species, such as Arabidopsis thaliana and Oryza sativa, most TAGs are the result of unequal chromosomal crossover during genetic recombination.
See also
Satellite DNA
Tandem repeats
Notes
References
Repetitive DNA sequences
Genes
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https://en.wikipedia.org/wiki/Balance%20spring
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A balance spring, or hairspring, is a spring attached to the balance wheel in mechanical timepieces. It causes the balance wheel to oscillate with a resonant frequency when the timepiece is running, which controls the speed at which the wheels of the timepiece turn, thus the rate of movement of the hands. A regulator lever is often fitted, which can be used to alter the free length of the spring and thereby adjust the rate of the timepiece.
The balance spring is a fine spiral or helical torsion spring used in mechanical watches, alarm clocks, kitchen timers, marine chronometers, and other timekeeping mechanisms to control the rate of oscillation of the balance wheel. The balance spring is an essential adjunct to the balance wheel, causing it to oscillate back and forth. The balance spring and balance wheel together form a harmonic oscillator, which oscillates with a precise period or "beat" resisting external disturbances, and is responsible for timekeeping accuracy.
The addition of the balance spring to the balance wheel around 1657 by Robert Hooke and Christiaan Huygens greatly increased the accuracy of portable timepieces, transforming early pocketwatches from expensive novelties to useful timekeepers. Improvements to the balance spring are responsible for further large increases in accuracy since that time. Modern balance springs are made of special low temperature coefficient alloys like nivarox to reduce the effects of temperature changes on the rate, and careful
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https://en.wikipedia.org/wiki/The%20Castle%20of%20the%20Otter
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The Castle of the Otter is a collection of essays and other non-fiction by Gene Wolfe, related to his Book of the New Sun tetralogy. It takes its title from an incorrect announcement of Wolfe's final volume in Locus. The Citadel of the Autarch was the actual name of the final work in the series. Wolfe liked the inaccurate title, though, and reused it as the name for a companion work of non-fiction essays and unused materials from the series (including an article about how Otter got its title).
The Castle of the Otter (1982, ) is something of a collector's item; its first edition sold out before its publication date. Originally published as a small press edition by Ziesing Brothers, it was later offered for sale through the Science Fiction Book Club.
The material in Castle of the Otter was combined with his short story collection Gene Wolfe's Book of Days to make the volume Castle of Days.
Reception
Algis Budrys "commended" the collection to readers of his review column, describing it as "a book not just about a book, but about books and literacy."
References
1982 books
Fantasy books
Essay collections
Works by Gene Wolfe
Solar Cycle
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https://en.wikipedia.org/wiki/Algodonite
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Algodonite is a copper arsenide mineral with formula: Cu6As. It is a gray white metallic mineral crystallizing in the hexagonal system. It has a Mohs hardness of 4 and a specific gravity of 8.38 - 8.72.
It was first described in 1857 from the Algodones silver mine, Coquimbo, Chile.
References
Copper minerals
Arsenide minerals
Hexagonal minerals
Minerals in space group 194
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https://en.wikipedia.org/wiki/Robbinsdale%20Area%20Schools
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Robbinsdale School District 281 is a school district centered in Robbinsdale, Minnesota, in the northwestern suburbs of Minneapolis, Minnesota, USA. The district includes all of Robbinsdale, Crystal, and New Hope, and parts of Brooklyn Center, Brooklyn Park, Plymouth, and Golden Valley.
Schools
Elementary schools
Forest Elementary (Crystal)
Lakeview Elementary (Robbinsdale)
Meadow Lake Elementary (New Hope)
Neill Elementary (Golden Valley)
Noble Elementary (Golden Valley)
Northport Elementary (Brooklyn Center)
Sonnesyn Elementary (New Hope)
Zachary Lane Elementary (Plymouth)
School of Engineering and Arts (Golden Valley)
Magnet schools
FAIR School Crystal, Grades 4-8 (located at FAIR School Crystal)
FAIR School Pilgrim Lane, K-1 (located at Pilgrim Lane Elementary, Plymouth; grades K-3 to be offered by fall 2019)
Robbinsdale Spanish Immersion School or RSI (located at Sunny Hollow Elementary, New Hope)
School of Engineering and Arts or SEA, (located at Olson Elementary, Golden Valley)
Middle schools
Plymouth Middle School (Plymouth)
Robbinsdale Middle School (Robbinsdale)
Sandburg Middle School, (Golden Valley)
(closed in 2009, reopened in 2017)
High schools
Highview Alternative Program (Golden Valley)
Robbinsdale Armstrong High School, (Plymouth)
Robbinsdale Cooper High School (New Hope)
Other facilities
Education Service Center/Bus Garage, New Hope
New Hope Learning Center, New Hope
Robbinsdale Area Learning Campus (RALC), Robbinsdale
Crystal
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https://en.wikipedia.org/wiki/Karyolysis
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Karyolysis (from Greek κάρυον karyon—kernel, seed, or nucleus), and λύσις lysis from λύειν lyein, "to separate") is the complete dissolution of the chromatin of a dying cell due to the enzymatic degradation by endonucleases. The whole cell will eventually stain uniformly with eosin after karyolysis. It is usually associated with karyorrhexis and occurs mainly as a result of necrosis, while in apoptosis after karyorrhexis the nucleus usually dissolves into apoptotic bodies.
Disintegration of the cytoplasm, pyknosis of the nuclei, and karyolysis of the nuclei of scattered transitional cells may be seen in urine from healthy individuals as well as in urine containing malignant cells. Cells with an attached tag of partially preserved cytoplasm were initially described by Papanicolaou and are sometimes called comet or decoy cells. They may have some of the characteristics of malignancy, and it is therefore important that they be recognized for what they are.
Additional images
See also
Apoptosis
Necrosis
Pyknosis
Karyorrhexis
References
Cellular processes
Cellular senescence
Programmed cell death
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https://en.wikipedia.org/wiki/HMAC-based%20one-time%20password
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HMAC-based one-time password (HOTP) is a one-time password (OTP) algorithm based on HMAC. It is a cornerstone of the Initiative for Open Authentication (OATH).
HOTP was published as an informational IETF RFC 4226 in December 2005, documenting the algorithm along with a Java implementation. Since then, the algorithm has been adopted by many companies worldwide (see below). The HOTP algorithm is a freely available open standard.
Algorithm
The HOTP algorithm provides a method of authentication by symmetric generation of human-readable passwords, or values, each used for only one authentication attempt. The one-time property leads directly from the single use of each counter value.
Parties intending to use HOTP must establish some ; typically these are specified by the authenticator, and either accepted or not by the authenticated:
A cryptographic hash method H (default is SHA-1)
A secret key K, which is an arbitrary byte string and must remain private
A counter C, which counts the number of iterations
A HOTP value length d (6–10, default is 6, and 6–8 is recommended)
Both parties compute the HOTP value derived from the secret key K and the counter C. Then the authenticator checks its locally generated value against the value supplied by the authenticated.
The authenticator and the authenticated increment the counter C independently of each other, where the latter may increase ahead of the former, thus a resynchronisation protocol is wise. does not actually require any
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https://en.wikipedia.org/wiki/Yttrocerite
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Yttrocerite is a variety of the mineral fluorite with a chemical formula CaF2+(Y,Ce)F3. It is bluish red with isometric crystals and is named for the yttrium and cerium it contains. It has a Mohs hardness of 4–5. It has been found in Sweden, several states in the United States and Norway. It is not a mineral species approved by International Mineralogical Association.
References
Marie-Nicolas Bouillet, Dictionnaire universel des sciences, des lettres et des arts, 1896.
Calcium minerals
Yttrium minerals
Fluorine minerals
Lanthanide minerals
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https://en.wikipedia.org/wiki/DPLL%20algorithm
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In logic and computer science, the Davis–Putnam–Logemann–Loveland (DPLL) algorithm is a complete, backtracking-based search algorithm for deciding the satisfiability of propositional logic formulae in conjunctive normal form, i.e. for solving the CNF-SAT problem.
It was introduced in 1961 by Martin Davis, George Logemann and Donald W. Loveland and is a refinement of the earlier Davis–Putnam algorithm, which is a resolution-based procedure developed by Davis and Hilary Putnam in 1960. Especially in older publications, the Davis–Logemann–Loveland algorithm is often referred to as the "Davis–Putnam method" or the "DP algorithm". Other common names that maintain the distinction are DLL and DPLL.
Implementations and applications
The SAT problem is important both from theoretical and practical points of view. In complexity theory it was the first problem proved to be NP-complete, and can appear in a broad variety of applications such as model checking, automated planning and scheduling, and diagnosis in artificial intelligence.
As such, writing efficient SAT solvers has been a research topic for many years. GRASP (1996-1999) was an early implementation using DPLL. In the international SAT competitions, implementations based around DPLL such as zChaff and MiniSat were in the first places of the competitions in 2004 and 2005.
Another application that often involves DPLL is automated theorem proving or satisfiability modulo theories (SMT), which is a SAT problem in which proposit
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https://en.wikipedia.org/wiki/Equilibrium%20thermodynamics
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Equilibrium Thermodynamics is the systematic study of transformations of matter and energy in systems in terms of a concept called thermodynamic equilibrium. The word equilibrium implies a state of balance. Equilibrium thermodynamics, in origins, derives from analysis of the Carnot cycle. Here, typically a system, as cylinder of gas, initially in its own state of internal thermodynamic equilibrium, is set out of balance via heat input from a combustion reaction. Then, through a series of steps, as the system settles into its final equilibrium state, work is extracted.
In an equilibrium state the potentials, or driving forces, within the system, are in exact balance. A central aim in equilibrium thermodynamics is: given a system in a well-defined initial state of thermodynamic equilibrium, subject to accurately specified constraints, to calculate, when the constraints are changed by an externally imposed intervention, what the state of the system will be once it has reached a new equilibrium. An equilibrium state is mathematically ascertained by seeking the extrema of a thermodynamic potential function, whose nature depends on the constraints imposed on the system. For example, a chemical reaction at constant temperature and pressure will reach equilibrium at a minimum of its components' Gibbs free energy and a maximum of their entropy.
Equilibrium thermodynamics differs from non-equilibrium thermodynamics, in that, with the latter, the state of the system under inv
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https://en.wikipedia.org/wiki/Thermodynamic%20state
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In thermodynamics, a thermodynamic state of a system is its condition at a specific time; that is, fully identified by values of a suitable set of parameters known as state variables, state parameters or thermodynamic variables. Once such a set of values of thermodynamic variables has been specified for a system, the values of all thermodynamic properties of the system are uniquely determined. Usually, by default, a thermodynamic state is taken to be one of thermodynamic equilibrium. This means that the state is not merely the condition of the system at a specific time, but that the condition is the same, unchanging, over an indefinitely long duration of time.
Thermodynamics sets up an idealized conceptual structure that can be summarized by a formal scheme of definitions and postulates. Thermodynamic states are amongst the fundamental or primitive objects or notions of the scheme, for which their existence is primary and definitive, rather than being derived or constructed from other concepts.
A thermodynamic system is not simply a physical system. Rather, in general, infinitely many different alternative physical systems comprise a given thermodynamic system, because in general a physical system has vastly many more microscopic characteristics than are mentioned in a thermodynamic description. A thermodynamic system is a macroscopic object, the microscopic details of which are not explicitly considered in its thermodynamic description. The number of state variables requir
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https://en.wikipedia.org/wiki/Biological%20thermodynamics
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Biological thermodynamics (Thermodynamics of biological systems) is a science that explains the nature and general laws of thermodynamic processes occurring in living organisms as nonequilibrium thermodynamic systems that convert the energy of the Sun and food into other types of energy. The nonequilibrium thermodynamic state of living organisms is ensured by the continuous alternation of cycles of controlled biochemical reactions, accompanied by the release and absorption of energy, which provides them with the properties of phenotypic adaptation and a number of others.
History
In 1935, the first scientific work devoted to the thermodynamics of biological systems was published - the book of the Hungarian-Russian theoretical biologist Erwin S. Bauer (1890-1938) "Theoretical Biology"[]. E. Bauer formulated the "Universal Law of Biology" in the following edition: "All and only living systems are never in equilibrium and perform constant work at the expense of their free energy against the equilibrium required by the laws of physics and chemistry under existing external conditions". This law can be considered the 1st law of thermodynamics of biological systems.
In 1957, German-British physician and biochemist Hans Krebs and British-American biochemist Hans Kornberg[] in the book "Energy Transformations in Living Matter" first described the thermodynamics of biochemical reactions. In their works, H. Krebs and Hans Kornberg showed how in living cells, as a result of biochemica
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https://en.wikipedia.org/wiki/Gramicidin%20S
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Gramicidin S or Gramicidin Soviet is an antibiotic that is effective against some gram-positive and gram-negative bacteria as well as some fungi.
It is a derivative of gramicidin, produced by the gram-positive bacterium Brevibacillus brevis. Gramicidin S is a cyclodecapeptide, constructed as two identical pentapeptides joined head to tail, formally written as cyclo(-Val-Orn-Leu-D-Phe-Pro-)2. That is to say, it forms a ring structure composed of five different amino acids, each one used twice within the structure. Another interesting point is that it utilizes two amino acids uncommon in peptides: ornithine as well as the atypical stereoisomer of phenylalanine. It is synthesized by gramicidin S synthetase.
Biosynthesis
Gramicidin S biosynthetic pathway consists of two-enzyme of nonribosomal peptide synthases (NRPSs), gramicidin S synthetase I (GrsA) and gramicidin S synthetase II (GrsB), to give a product as a cyclic decapeptide. Within the biosynthetic pathway, there are total of five modules that specifically recognize, activate, and condense the amino acids to gramicidin S. Starting module GrsA consists of three domains: Adenylation (A) domain where it incorporates the amino acid and activates it by adenylation using ATP, Thiolation (T) domain or peptidyl carrier protein (PCP) in which the adenylated amino acid gets covalently attached to the 4´-phosphopantetheine group and this gets loaded onto the conserved serine in the T domain, Epimerization (E) domain where it epi
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https://en.wikipedia.org/wiki/Atriphtaloid
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An atriphtaloid, also called an atriphtothlassic curve, is type of sextic plane curve. It is given by the equation
where a and b are positive numbers.
References
Sextic curves
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https://en.wikipedia.org/wiki/Butterfly%20curve%20%28transcendental%29
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The butterfly curve is a transcendental plane curve discovered by Temple H. Fay of University of Southern Mississippi in 1989.
Equation
The curve is given by the following parametric equations:
or by the following polar equation:
The term has been added for purely aesthetic reasons, to make the butterfly appear fuller and more pleasing to the eye.
Developments
In 2006, two mathematicians using Mathematica analyzed the function, and found variants where leaves, flowers or other insects became apparent.
See also
https://books.google.com/books?id=AsYaCgAAQBAJ&dq=OSCAR+RAMIREZ+POLAR+EQUATION&pg=PA732
Butterfly curve (algebraic)
Oscar’s Butterfly Polar Equation
r = (cos 5θ)2 + sin 3θ + 0.3 for 0 ≤ θ ≤ 6π
(A polar equation discovered by Oscar Ramirez, a UCLA student, in the fall of 1991.)
References
External links
Butterfly Curve plotted in WolframAlpha
Plane curves
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https://en.wikipedia.org/wiki/Quadrifolium
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The quadrifolium (also known as four-leaved clover) is a type of rose curve with an angular frequency of 2. It has the polar equation:
with corresponding algebraic equation
Rotated counter-clockwise by 45°, this becomes
with corresponding algebraic equation
In either form, it is a plane algebraic curve of genus zero.
The dual curve to the quadrifolium is
The area inside the quadrifolium is , which is exactly half of the area of the circumcircle of the quadrifolium. The perimeter of the quadrifolium is
where is the complete elliptic integral of the second kind with modulus , is the arithmetic–geometric mean and denotes the derivative with respect to the second variable.
Notes
References
External links
Interactive example with JSXGraph
Sextic curves
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https://en.wikipedia.org/wiki/Selectin
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The selectins (cluster of differentiation 62 or CD62) are a family of cell adhesion molecules (or CAMs). All selectins are single-chain transmembrane glycoproteins that share similar properties to C-type lectins due to a related amino terminus and calcium-dependent binding. Selectins bind to sugar moieties and so are considered to be a type of lectin, cell adhesion proteins that bind sugar polymers.
Structure
All three known members of the selectin family (L-, E-, and P-selectin) share a similar cassette structure: an N-terminal, calcium-dependent lectin domain, an epidermal growth factor (EGF)-like domain, a variable number of consensus repeat units (2, 6, and 9 for L-, E-, and P-selectin, respectively), a transmembrane domain (TM) and an intracellular cytoplasmic tail (cyto). The transmembrane and cytoplasmic parts are not conserved across the selectins being responsible for their targeting to different compartments. Though they share common elements, their tissue distribution and binding kinetics are quite different, reflecting their divergent roles in various pathophysiological processes.
Types
There are three subsets of selectins:
E-selectin (in endothelial cells)
L-selectin (in leukocytes)
P-selectin (in platelets and endothelial cells)
L-selectin is the smallest of the vascular selectins, expressed on all granulocytes and monocytes and on most lymphocytes, can be found in most leukocytes.
P-selectin, the largest selectin, is stored in α-granules of platelets
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https://en.wikipedia.org/wiki/Stratum%20spinosum
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The stratum spinosum (or spinous layer/prickle cell layer) is a layer of the epidermis found between the stratum granulosum and stratum basale. This layer is composed of polyhedral keratinocytes. These are joined with desmosomes. Their spiny (Latin, spinosum) appearance is due to shrinking of the microfilaments between desmosomes that occurs when stained with H&E. Keratinization begins in the stratum spinosum, although the actual keratinocytes begin in the stratum basale. They have large pale-staining nuclei as they are active in synthesizing fibrilar proteins, known as cytokeratin, which build up within the cells aggregating together forming tonofibrils. The tonofibrils go on to form the desmosomes, which allow for strong connections to form between adjacent keratinocytes. The stratum spinosum also contains Langerhans cells, which functions as a macrophage by engulfing bacteria, foreign particles, and damaged cells that occur in this layer.
Clinical significance
Diffuse hyperplasia of the stratum spinosum is termed acanthosis.
Additional images
See also
Spinous cell
References
Skin anatomy
Epithelial cells
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https://en.wikipedia.org/wiki/Stability%20%28probability%29
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In probability theory, the stability of a random variable is the property that a linear combination of two independent copies of the variable has the same distribution, up to location and scale parameters. The distributions of random variables having this property are said to be "stable distributions". Results available in probability theory show that all possible distributions having this property are members of a four-parameter family of distributions. The article on the stable distribution describes this family together with some of the properties of these distributions.
The importance in probability theory of "stability" and of the stable family of probability distributions is that they are "attractors" for properly normed sums of independent and identically distributed random variables.
Important special cases of stable distributions are the normal distribution, the Cauchy distribution and the Lévy distribution. For details see stable distribution.
Definition
There are several basic definitions for what is meant by stability. Some are based on summations of random variables and others on properties of characteristic functions.
Definition via distribution functions
Feller makes the following basic definition. A random variable X is called stable (has a stable distribution) if, for n independent copies Xi of X, there exist constants cn > 0 and dn such that
where this equality refers to equality of distributions. A conclusion drawn from this starting point is that
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https://en.wikipedia.org/wiki/Ddoc
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Ddoc is a compiler-embedded documentation generator and associated syntax, for the D programming language, designed by Walter Bright. Its emphasis is on being able to write documentation in code comments in a natural style, minimizing the need for embedded markup and thus improving the legibility of the code comments. It is similar in concept to Doxygen and Javadoc.
Code comments are associated with symbols in the code, and Ddoc uses the semantic and syntactic information available from the D compiler to fill in routine information such as parameters and return types automatically.
The code comments and symbol table information are processed by Ddoc into an internal structured format. Each of these structures corresponds to a template expressed as a macro. The template macros convert the structured format into another set of macros that express the markup. The latter set of markup macros are expanded to produce, by default, HTML.
Both the template macros and the markup macros can be overridden by the user, and can be applied via external files analogous to HTML style sheets. The template macros can be changed to customize the high level formatting, and the markup macros can be altered to produce other output forms such as XML and XHTML.
Compiler options
Several compiler options are available to cause the dmd D compiler to output an HTML documentation file:
generate documentation - output will be the same name as the D source file, with the ".d" extension
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https://en.wikipedia.org/wiki/Penge%20Urban%20District
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Penge was a civil parish and a local government district located to the southeast of London, England. It included the settlements of Penge, Anerley and part of Crystal Palace. It was part of the London postal district, Metropolitan Police District and, from 1933, the London Passenger Transport Area. In 1965 the urban district was abolished by the London Government Act 1963 and it became part of Greater London, being combined with other districts to form the London Borough of Bromley.
Background
Penge was a detached hamlet of the ancient parish of Battersea in the Brixton hundred of Surrey.
Parish in the Metropolis
Battersea became part of the area administered by the Metropolitan Board of Works in 1855 and the main part of the parish was grouped into the Wandsworth District, whilst Penge became part of the Lewisham District. It formed part of the London School Board area established in 1870. Penge became part of the Croydon Poor Law Union under the New Poor Law, thus it was part of Surrey for poor law and registration purposes and did not form part of the Metropolitan Asylums District established in 1867.
Penge remained formally part of the parish of Battersea, however it was established in 1859 that the two parts of the parish held separate funds and Penge had distinct local government arrangements. In 1866 it became a separate civil parish in its own right. In 1876 an application was made to the Local Government Board that the Vestries Act 1850 should apply to the parish
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https://en.wikipedia.org/wiki/Tarski%E2%80%93Kuratowski%20algorithm
|
In computability theory and mathematical logic the Tarski–Kuratowski algorithm is a non-deterministic algorithm that produces an upper bound for the complexity of a given formula in the arithmetical hierarchy and analytical hierarchy.
The algorithm is named after Alfred Tarski and Kazimierz Kuratowski.
Algorithm
The Tarski–Kuratowski algorithm for the arithmetical hierarchy consists of the following steps:
Convert the formula to prenex normal form. (This is the non-deterministic part of the algorithm, as there may be more than one valid prenex normal form for the given formula.)
If the formula is quantifier-free, it is in and .
Otherwise, count the number of alternations of quantifiers; call this k.
If the first quantifier is ∃, the formula is in .
If the first quantifier is ∀, the formula is in .
References
Rogers, Hartley The Theory of Recursive Functions and Effective Computability, MIT Press. ;
Mathematical logic hierarchies
Computability theory
Theory of computation
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https://en.wikipedia.org/wiki/Blum%27s%20speedup%20theorem
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In computational complexity theory, Blum's speedup theorem, first stated by Manuel Blum in 1967, is a fundamental theorem about the complexity of computable functions.
Each computable function has an infinite number of different program representations in a given programming language. In the theory of algorithms one often strives to find a program with the smallest complexity for a given computable function and a given complexity measure (such a program could be called optimal). Blum's speedup theorem shows that for any complexity measure, there exists a computable function such that there is no optimal program computing it, because every program has a program of lower complexity. This also rules out the idea there is a way to assign to arbitrary functions their computational complexity, meaning the assignment to any f of the complexity of an optimal program for f. This does of course not exclude the possibility of finding the complexity of an optimal program for certain specific functions.
Speedup theorem
Given a Blum complexity measure and a total computable function with two parameters, then there exists a total computable predicate (a boolean valued computable function) so that for every program for , there exists a program for so that for almost all
is called the speedup function. The fact that it may be as fast-growing as desired
(as long as it is computable) means that the phenomenon of always having a program of smaller complexity remains even if by "smal
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https://en.wikipedia.org/wiki/Oricon
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, established in 1999, is the holding company at the head of a Japanese corporate group that supplies statistics and information on music and the music industry in Japan and Western music. It started as, which was founded by Sōkō Koike in November 1967 and became known for its music charts. Oricon Inc. was originally set up as a subsidiary of Original Confidence and took over the latter's Oricon record charts in April 2002.
The charts are compiled from data drawn from some 39,700 retail outlets (as of April 2011) and provide sales rankings of music CDs, DVDs, electronic games, and other entertainment products based on weekly tabulations. Results are announced every Tuesday and published in Oricon Style by subsidiary Oricon Entertainment Inc. The group also lists panel survey-based popularity ratings for television commercials on its official website.
Oricon started publishing Combined Chart, which includes CD sales, digital sales, and streaming together, on December 19, 2018.
History
Original Confidence Inc., the original Oricon company, was founded by the former Snow Brand Milk Products promoter Sōkō Koike in 1967. That November, the company began publishing a singles chart on an experimental basis.
Entitled , this went official on January 4, 1968.
Like the preceding Japanese music charts provided by Tokushin Music Report which was started in 1962, early Original Confidence was an exclusive information magazine only for the people who worked in the music industry. In t
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https://en.wikipedia.org/wiki/Ron%20Davis%20%28pitcher%29
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Ronald Gene Davis (born August 6, 1955) is a former Major League Baseball pitcher who played 11 years from 1978 to 1988. Davis played for the New York Yankees and Minnesota Twins of the American League and the Chicago Cubs, Los Angeles Dodgers, and San Francisco Giants of the National League. He was selected to the American League All-Star team in 1981.
Life and career
Davis was born in Houston, Texas. Standing 6' 4", he was a hard-throwing right-handed relief pitcher. During his career he appeared in 481 games all in relief, and recorded 130 saves.
Originally drafted by the Chicago Cubs, he was traded while still in the minor leagues to the New York Yankees in 1978. While in New York he was used as the team's closer after an injury to All-Star relief pitcher Rich Gossage from a fight with teammate Cliff Johnson. Also, while with the Yankees, he was one of the first pitchers ever to be used exclusively as a middle-inning "set-up" pitcher for his team's closer. For two seasons, 1980 and 1981, Davis and Gossage were an effective tandem, and many teams have followed this pitching formula to this day.
Davis still holds the Yankee team record for most consecutive strikeouts in a single game with eight, recorded on May 4, 1981, against the California Angels. This accomplishment also gives him the team record for most strikeouts by a relief pitcher in a single game. The record was tied by Michael King on April 22, 2022, when he struck out 8 of 9 batters in relief.
During the 19
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https://en.wikipedia.org/wiki/Polyworld
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Polyworld is a cross-platform (Linux, Mac OS X) program written by Larry Yaeger to evolve Artificial Intelligence through natural selection and evolutionary algorithms.
It uses the Qt graphics toolkit and OpenGL to display a graphical environment in which a population of trapezoid agents search for food, mate, have offspring, and prey on each other. The population is typically only in the hundreds, as each individual is rather complex and the environment consumes considerable computer resources. The graphical environment is necessary since the individuals actually move around the 2-D plane and must be able to "see." Since some basic abilities, like eating carcasses or randomly generated food, seeing other individuals, mating or fighting with them, etc., are possible, a number of interesting behaviours have been observed to spontaneously arise after prolonged evolution, such as cannibalism, predators and prey, and mimicry.
Each individual makes decisions based on a neural net using Hebbian learning; the neural net is derived from each individual's genome. The genome does not merely specify the wiring of the neural nets, but also determines their size, speed, color, mutation rate and a number of other factors. The genome is randomly mutated at a set probability, which are also changed in descendant organisms.
External links
Github entry
Yaeger's page on Polyworld
Google TechTalk about Polyworld
Applications of artificial intelligence
Artificial life
Digital organisms
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https://en.wikipedia.org/wiki/Giron%2C%20Ain
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Giron () is a commune in the Ain department in eastern France.
Geography
Climate
Giron has a oceanic climate (Köppen climate classification Cfb). The average annual temperature in Giron is . The average annual rainfall is with December as the wettest month. The temperatures are highest on average in July, at around , and lowest in January, at around . The highest temperature ever recorded in Giron was on 13 August 2003; the coldest temperature ever recorded was on 12 January 1987.
Population
See also
Communes of the Ain department
References
Communes of Ain
Ain communes articles needing translation from French Wikipedia
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https://en.wikipedia.org/wiki/Chris%20Lilley%20%28computer%20scientist%29
|
Chris Lilley (born 1959 in the UK) is a British computer scientist known for co-authoring the Portable Network Graphics (PNG) format, starting the Scalable Vector Graphics (SVG) format, and his work on HTML2, CSS2, and Web fonts.
Education
Lilley was educated at Broxburn Academy in West Lothian, Scotland. In 1983, he obtained a bachelor's degree in Biochemistry at the University of Stirling, Scotland.
In 1990, he obtained a master's degree in Computing at the University of York.
Career
After his bachelor's degree in Biochemistry he worked in Haematology and Blood transfusion at the hospital laboratories of Stirling and Falkirk for a few years before eventually switching to Computer Science.
Around 1990, he worked at the Computer Graphics Unit at the University of Manchester as a technical author and electronic teaching specialist in the field of Computer Graphics and Scientific Visualization. While at Manchester he was a member of the IETF Working Group on HTML, developing HTML 2.0, and was also one of the authors of the PNG raster graphics format. In 1994 he was a consulting student on the Biocomputing course run by the GNA's Virtual School of Natural Sciences, where he obtained a postgraduate diploma in Bioinformatics. In 1993 he presented a paper at the Eurographics Workshop on Graphics and Visualisation Education in Barcelona on the potential of the World Wide Web for technical education in Computer Graphics.
In 1994 he attended the First International World Wide
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https://en.wikipedia.org/wiki/Loyettes
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Loyette () is a commune in the Ain department in eastern France.
Geography
Climate
Loyettes has a oceanic climate (Köppen climate classification Cfb). The average annual temperature in Loyettes is . The average annual rainfall is with October as the wettest month. The temperatures are highest on average in July, at around , and lowest in January, at around . The highest temperature ever recorded in Loyettes was on 13 August 2003; the coldest temperature ever recorded was on 20 December 2009.
Population
See also
Communes of the Ain department
References
Communes of Ain
Ain communes articles needing translation from French Wikipedia
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https://en.wikipedia.org/wiki/Polynucleotide
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In molecular biology, a polynucleotide () is a biopolymer composed of nucleotide monomers that are covalently bonded in a chain. DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are examples of polynucleotides with distinct biological functions. DNA consists of two chains of polynucleotides, with each chain in the form of a helix (like a spiral staircase).
Sequence
Although DNA and RNA do not generally occur in the same polynucleotide, the four species of nucleotides may occur in any order in the chain. The sequence of DNA or RNA species for a given polynucleotide is the main factor determining its function in a living organism or a scientific experiment.
Polynucleotides in organisms
Polynucleotides occur naturally in all living organisms. The genome of an organism consists of complementary pairs of enormously long polynucleotides wound around each other in the form of a double helix. Polynucleotides have a variety of other roles in organisms.
Polynucleotides in scientific experiments
Polynucleotides are used in biochemical experiments such as polymerase chain reaction (PCR) or DNA sequencing. Polynucleotides are made artificially from oligonucleotides, smaller nucleotide chains with generally fewer than 30 subunits. A polymerase enzyme is used to extend the chain by adding nucleotides according to a pattern specified by the scientist.
Prebiotic condensation of nucleobases with ribose
In order to understand how life arose, knowledge is required of the chemical p
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https://en.wikipedia.org/wiki/DNA%20polymerase%20II
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DNA polymerase II (also known as DNA Pol II or Pol II) is a prokaryotic DNA-dependent DNA polymerase encoded by the PolB gene.
DNA Polymerase II is an 89.9-kDa protein and is a member of the B family of DNA polymerases. It was originally isolated by Thomas Kornberg in 1970, and characterized over the next few years. The in vivo functionality of Pol II is under debate, yet consensus shows that Pol II is primarily involved as a backup enzyme in prokaryotic DNA replication. The enzyme has 5′→3′ DNA synthesis capability as well as 3′→5′ exonuclease proofreading activity. DNA Pol II interacts with multiple binding partners common with DNA Pol III in order to enhance its fidelity and processivity.
Discovery
DNA polymerase I was the first DNA-directed DNA polymerase to be isolated from E. coli. Several studies involving this isolated enzyme indicated that DNA pol I was most likely involved in repair replication and was not the main replicative polymerase. In order to better understand the in vivo role of DNA pol I, E. coli mutants deficient in this enzyme (termed Pol A1−) were generated in 1969 by De Lucia and Cairns. As characterized, this new mutant strain was more sensitive to ultraviolet light, corroborating the hypothesis that DNA pol I was involved in repair replication. The mutant grew at the same rate as the wild type, indicating the presence of another enzyme responsible for DNA replication. The isolation and characterization of this new polymerase involved in semicons
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https://en.wikipedia.org/wiki/Five%20Equations%20That%20Changed%20the%20World
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Five Equations That Changed the World: The Power and Poetry of Mathematics is a book by Michael Guillen, published in 1995.
It is divided into five chapters that talk about five different equations in physics and the people who have developed them.
The scientists and their equations are:
Isaac Newton (Universal Law of Gravity)
Daniel Bernoulli (Law of Hydrodynamic Pressure)
Michael Faraday (Law of Electromagnetic Induction)
Rudolf Clausius (Second Law of Thermodynamics)
Albert Einstein (Theory of Special Relativity)
The book is a light study in science and history, portraying the preludes to and times and settings of discoveries that have been the basis of further development, including space travel, flight and nuclear power. Each chapter of the book is divided into sections titled Veni, Vidi, Vici.
The reviews of the book have been mixed. Publishers Weekly called it "wholly accessible, beautifully written", Kirkus Reviews wrote that it is a "crowd-pleasing kind of book designed to make the science as palatable as possible", and Frank Mahnke wrote that Guillen "has a nice touch for the history of mathematics and physics and their impact on the world". However, in contrast, Charles Stephens panned "the superficiality of the author's treatment of scientific ideas", and the editors of The Capital Times called the book a "miserable failure" at its goal of helping the public appreciate the beauty of mathematics.
References
1995 non-fiction books
Popular physics books
Mat
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https://en.wikipedia.org/wiki/Sudarsky%27s%20gas%20giant%20classification
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Sudarsky's classification of gas giants for the purpose of predicting their appearance based on their temperature was outlined by David Sudarsky and colleagues in the paper Albedo and Reflection Spectra of Extrasolar Giant Planets and expanded on in Theoretical Spectra and Atmospheres of Extrasolar Giant Planets, published before any successful direct or indirect observation of an extrasolar planet atmosphere was made. It is a broad classification system with the goal of bringing some order to the likely rich variety of extrasolar gas-giant atmospheres.
Gas giants are split into five classes (numbered using Roman numerals) according to their modeled physical atmospheric properties. In the Solar System, only Jupiter and Saturn are within the Sudarsky classification, and both are Class I.
The appearance of planets that are not gas giants cannot be predicted by the Sudarsky system, for example terrestrial planets such as Earth and Venus, or ice giants such as Uranus (14 Earth masses) and Neptune (17 Earth masses).
Background
The appearance of extrasolar planets is largely unknown because of the difficulty in making direct observations. In addition, analogies with planets in the Solar System can apply to few of the extrasolar planets known because most are wholly unlike any of our planets, for example, the hot Jupiters.
Bodies that transit their star can be spectrographically mapped, for instance HD 189733 b. That planet has further been shown to be blue with an albedo greate
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https://en.wikipedia.org/wiki/State%20of%20Origin%20results%20and%20statistics
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State of Origin results and statistics have been accumulating since the 1980 State of Origin game. Every game played under State of Origin selection rules, including the additional 1987 exhibition match and the matches played between New South Wales and Queensland for the Super League Tri-series are detailed below unless stated otherwise.
Results
Series matches
Queensland have won 24 series. NSW have won 16. On 2 occasion have both teams drawn a series (1999, 2002). (As of 2023)
One off matches
The matches in 1980 and 1981 were one off experimental matches after New South Wales had already won the interstate series in both years. Both games count toward official statistics, but are not considered series.
After Queensland had won the 1987 State of Origin series 2–1, a further game was played in Long Beach, California to showcase rugby league to the American public. On 15 July 2003 the Australian Rugby League announced that this game was to be classified as an "official match" and that the match would count towards the players' individual statistics and overall match win–loss–draw records. However, the match does not count towards the series win–loss–draw record and the 1987 series still remains a 2–1 win to Queensland.
Super League
New South Wales and Queensland played two matches against each other under State of Origin selection rules using players from the Super League (Australia) competition. These matches were not sanctioned by the Australian Rugby League and are n
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https://en.wikipedia.org/wiki/Regency%20TR-1
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The Regency TR-1 was the first commercially manufactured transistor radio, introduced in 1954. Despite mediocre performance, about 150,000 units were sold, due to the novelty of its small size and portability. Previously, transistors had only been used in military or industrial applications, and the TR-1 demonstrated their utility for consumer electronics, offering a prescient glimpse of a future full of small, convenient hand-held devices that would develop into calculators, mobile phones, tablets and the like. Surviving specimens are sought out by collectors.
Conception
In May 1954, Texas Instruments, previously a producer of instrumentation for the oil industry and locating devices for the US Navy, was looking for an established radio manufacturer to develop and market a radio using their transistors. No major radio maker, including RCA, Philco, and Emerson, was interested. Ed Tudor, the president of Industrial Development Engineering Associates, (I.D.E.A), a builder of home antenna boosters, jumped at the opportunity to manufacture the TR-1, predicting sales of the transistor radios would be "20 million radios in three years."
The Regency Division of I.D.E.A announced the TR-1 on October 18, 1954, and put it on sale in November 1954.
Design
The Regency TR-1 circuitry was refined from the Texas Instruments drawings, reducing the number of parts, including two expensive transistors. Although this severely reduced audio output volume, it let I.D.E.A. keep the price down
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https://en.wikipedia.org/wiki/Activation-induced%20cytidine%20deaminase
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Activation-induced cytidine deaminase, also known as AICDA, AID and single-stranded DNA cytosine deaminase, is a 24 kDa enzyme which in humans is encoded by the AICDA gene. It creates mutations in DNA by deamination of cytosine base, which turns it into uracil (which is recognized as a thymine). In other words, it changes a C:G base pair into a U:G mismatch. The cell's DNA replication machinery recognizes the U as a T, and hence C:G is converted to a T:A base pair. During germinal center development of B lymphocytes, AID also generates other types of mutations, such as C:G to A:T. The mechanism by which these other mutations are created is not well understood. It is a member of the APOBEC family.
In B cells in the lymph nodes, AID causes mutations that produce antibody diversity, but that same mutation process leads to B cell lymphoma.
Function
This gene encodes a DNA-editing deaminase that is a member of the cytidine deaminase family. The protein is involved in somatic hypermutation, gene conversion, and class-switch recombination of immunoglobulin genes in B cells of the immune system.
AID is currently thought to be the master regulator of secondary antibody diversification. It is involved in the initiation of three separate immunoglobulin (Ig) diversification processes:
Somatic hypermutation (SHM), in which the antibody genes are minimally mutated to generate a library of antibody variants, some of which with higher affinity for a particular antigen than any of it
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https://en.wikipedia.org/wiki/Dirichlet%27s%20approximation%20theorem
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In number theory, Dirichlet's theorem on Diophantine approximation, also called Dirichlet's approximation theorem, states that for any real numbers and , with , there exist integers and such that and
Here represents the integer part of .
This is a fundamental result in Diophantine approximation, showing that any real number has a sequence of good rational approximations: in fact an immediate consequence is that for a given irrational α, the inequality
is satisfied by infinitely many integers p and q. This shows that any irrational number has irrationality measure at least 2. This corollary also shows that the Thue–Siegel–Roth theorem, a result in the other direction, provides essentially the tightest possible bound, in the sense that the bound on rational approximation of algebraic numbers cannot be improved by increasing the exponent beyond 2. The Thue–Siegel–Roth theorem uses advanced techniques of number theory, but many simpler numbers such as the golden ratio can be much more easily verified to be inapproximable beyond exponent 2. This exponent is referred to as the irrationality measure.
Simultaneous version
The simultaneous version of the Dirichlet's approximation theorem states that given real numbers and a natural number then there are integers such that
Method of proof
Proof by the pigeonhole principle
This theorem is a consequence of the pigeonhole principle. Peter Gustav Lejeune Dirichlet who proved the result used the same principle in other contex
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https://en.wikipedia.org/wiki/Stub%20%28electronics%29
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In microwave and radio-frequency engineering, a stub or resonant stub is a length of transmission line or waveguide that is connected at one end only. The free end of the stub is either left open-circuit, or short-circuited (as is always the case for waveguides). Neglecting transmission line losses, the input impedance of the stub is purely reactive; either capacitive or inductive, depending on the electrical length of the stub, and on whether it is open or short circuit. Stubs may thus function as capacitors, inductors and resonant circuits at radio frequencies.
The behaviour of stubs is due to standing waves along their length. Their reactive properties are determined by their physical length in relation to the wavelength of the radio waves. Therefore, stubs are most commonly used in UHF or microwave circuits in which the wavelengths are short enough that the stub is conveniently small. They are often used to replace discrete capacitors and inductors, because at UHF and microwave frequencies lumped components perform poorly due to parasitic reactance. Stubs are commonly used in antenna impedance matching circuits, frequency selective filters, and resonant circuits for UHF electronic oscillators and RF amplifiers.
Stubs can be constructed with any type of transmission line: parallel conductor line (where they are called Lecher lines), coaxial cable, stripline, waveguide, and dielectric waveguide. Stub circuits can be designed using a Smith chart, a graphical tool
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https://en.wikipedia.org/wiki/Kiddyphone
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Kiddyphone was a 1920s United Kingdom record label which issued small-sized gramophone records aimed at young children.
The label was owned by the Crystalate Gramophone Record Manufacturing Company Ltd., which also manufactured Imperial records. Some Kiddyphone releases were edited versions of recordings already issued on the Imperial label - this was also the case with Kiddyphone's sister label Mimosa.
Kiddyphone records were issued in three different sizes (7 inch, 5½ inch, and 6 inch) during the label's lifetime. As with many records of this type, the recording artists are not always credited on Kiddyphone record labels.
References
External links
Partial Kiddyphone catalog
Defunct record labels of the United Kingdom
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https://en.wikipedia.org/wiki/Shapefile
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The shapefile format is a geospatial vector data format for geographic information system (GIS) software. It is developed and regulated by Esri as a mostly open specification for data interoperability among Esri and other GIS software products. The shapefile format can spatially describe vector features: points, lines, and polygons, representing, for example, water wells, rivers, and lakes. Each item usually has attributes that describe it, such as name or temperature.
Overview
The shapefile format is a digital vector storage format for storing geographic location and associated attribute information. This format lacks the capacity to store topological information. The shapefile format was introduced with ArcView GIS version 2 in the early 1990s. It is now possible to read and write geographical datasets using the shapefile format with a wide variety of software.
The shapefile format stores the geometry as primitive geometric shapes like points, lines, and polygons. These shapes, together with data attributes that are linked to each shape, create the representation of the geographic data. The term "shapefile" is quite common, but the format consists of a collection of files with a common filename prefix, stored in the same directory. The three mandatory files have filename extensions , , and .dbf. The actual shapefile relates specifically to the file, but alone is incomplete for distribution as the other supporting files are required. Legacy GIS software may expect that
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https://en.wikipedia.org/wiki/Gene%20Loves%20Jezebel
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Gene Loves Jezebel are a British rock band formed in the early 1980s by brothers, Michael Aston and Jay Aston. Gene Loves Jezebel's best-known songs include "Heartache", "Desire (Come and Get It)" (1986), "The Motion of Love" (1987), "Jealous" (1990), and "Break the Chain" (1993), as well as alternative club hits "Bruises" (1983), "Influenza (Relapse)" (1984), "Shame", "Screaming for Emmalene" and "The Cow" (1985). "Desire" and "Heartache" were the most successful UK singles.
Early years: 1980–1989
Originally named Slavaryan by Michael , Gene Loves Jezebel was formed in 1980 with the Aston brothers, guitarist Ian Hudson, bassist Stephen Davis, and drummer Steve Snowy Evans. Essentially, Gene (Michael Aston) and Jezebel (Jay Aston) were a duo with a never-ending revolving door of back up players. The Astons grew up in Cornelly, and Michael later in Porthcawl, in Wales, and moved to London in 1981. With a new home, and shortly afterwards, the new name, the trio with bassist Julianne Regan and drummer James Chater (later replaced by John Murphy (the Associates) and then Richard Hawkins) played several live shows and were signed by Situation Two. Gene Loves Jezebel underwent numerous lineup changes between 1981 and 1985. In May 1982, Situation Two released Gene Loves Jezebel's demo and single, "Shaving My Neck". Regan exited within a year to form All About Eve. This left Ian Hudson briefly playing bass and Albie DeLuca as the guitar player until Stephen Marshall joined. "Desire"
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https://en.wikipedia.org/wiki/WKBF%20%28AM%29
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WKBF was a radio station licensed to Rock Island, Illinois, which last carried a regional Mexican format. The station's frequency was 1270 kHz, and was broadcast at a power of 5 kW. It last broadcast in Autumn 2018, and its license was cancelled on June 1, 2020. Its transmitter was located on 22nd Avenue (Old Colona Road) in Moline, alongside the Moline–East Moline border just off 53rd Street and Avenue of the Cities.
Station history
Early history
The history of the station dates to 1925, when businessman Calvin Beardsley purchased an experimental radio transmitter that operated in Cambridge, Illinois. He took the equipment and set it up at the rear of his store in Rock Island.
The station was first licensed on February 20, 1925, with the call sign WHBF, and broadcasting with 100 watts at 1350 kHz. The call letters were randomly assigned from a sequential roster of available call signs, however, they were said to stand for "Where Historic Blackhawk Fought".
Following the establishment of the Federal Radio Commission (FRC), stations were initially issued a series of temporary authorizations starting on May 3, 1927. In addition, they were informed that if they wanted to continue operating, they needed to file a formal license application by January 15, 1928, as the first step in determining whether they met the new "public interest, convenience, or necessity" standard. On May 25, 1928, the FRC issued General Order 32, which notified 164 stations, including WHBF, that "From
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