source
stringlengths 31
227
| text
stringlengths 9
2k
|
|---|---|
https://en.wikipedia.org/wiki/TRPC3
|
Short transient receptor potential channel 3 (TrpC3) also known as transient receptor protein 3 (TRP-3) is a protein that in humans is encoded by the TRPC3 gene. The TRPC3/6/7 subfamily are implicated in the regulation of vascular tone, cell growth, proliferation and pathological hypertrophy. These are diacylglycerol-sensitive cation channels known to regulate intracellular calcium via activation of the phospholipase C (PLC) pathway and/or by sensing Ca2+ store depletion. Together, their role in calcium homeostasis has made them potential therapeutic targets for a variety of central and peripheral pathologies.
Function
Non-specific cation conductance elicited by the activation of TrkB by BDNF is TRPC3-dependent in the CNS. TRPC channels are almost always co-localized with mGluR1-expressing cells and likely play a role in mGluR-mediated EPSPs.
The TRPC3 channel has been shown to be preferentially expressed in non-excitable cell types, such as oligodendrocytes. However, evidence suggests that active TRPC3 channels in basal ganglia (BG) output neurons are responsible for maintaining a tonic inward depolarizing current that regulates resting membrane potential and promotes regular neuronal firing. Conversely, inhibiting TRPC3 promotes cellular hyperpolarization, which can lead to slower and more irregular neuronal firing. While it's unclear if TRPC3 channels have equal expression, other members of the TRPC family have been localized to the axon hillock, cell body, and dendritic processes of dopamine-expressing cells.
The neuromodulator, substance P, activates TRPC3/7 channels inducing cellular currents that underlie rhythmic pacemaker activity in the brainstem, enhancing the regularity and frequency of respiratory rhythms, showing homology to the mechanism described in BG neurons. Transgenic cardiomyocytes expressing TRPC3 show prolonged action potential duration when exposed to a TRPC3 agonist. The same cardiomyocytes also increase their firing rate with agonist
|
https://en.wikipedia.org/wiki/GAUSS%20%28software%29
|
GAUSS is a matrix programming language for mathematics and statistics, developed and marketed by Aptech Systems. Its primary purpose is the solution of numerical problems in statistics, econometrics, time-series, optimization and 2D- and 3D-visualization. It was first published in 1984 for MS-DOS and is available for Linux, macOS and Windows.
Examples
GAUSS has several Application Modules as well as functions in its Run-Time Library (i.e., functions that come with GAUSS without extra cost)
Qprog – Quadratic programming
SqpSolvemt – Sequential quadratic programming
QNewton - Quasi-Newton unconstrained optimization
EQsolve - Nonlinear equations solver
GAUSS Applications
A range of toolboxes are available for GAUSS at additional cost.
See also
List of numerical-analysis software
Comparison of numerical-analysis software
|
https://en.wikipedia.org/wiki/Animal%20culture
|
Animal culture can be defined as the ability of non-human animals to learn and transmit behaviors through processes of social or cultural learning.
Culture is increasingly seen as a process, involving the social transmittance of behavior among peers and between generations. It can involve the transmission of novel behaviors or regional variations that are independent of genetic or ecological factors.
The existence of culture in non-humans has been a contentious subject, sometimes forcing researchers to rethink "what it is to be human".
The notion of culture in other animals dates back to Aristotle in classical antiquity, and more recently to Charles Darwin, but the association of other animals' actions with the actual word 'culture' originated with Japanese primatologists' discoveries of socially-transmitted food behaviours in the 1940s. Evidence for animal culture is often based on studies of
feeding behaviors, vocalizations, predator avoidance, mate selection, and migratory routes.
An important area of study for animal culture is vocal learning, the ability to make new sounds through imitation. Most species cannot learn to imitate sounds. Some can learn how to use innate vocalizations in new ways. Only a few species can learn new calls. The transmission of vocal repertoires, including some types of bird vocalization, can be viewed as social processes involving cultural transmission. Some evidence suggests that the ability to engage in vocal learning depends on the development of specialized brain circuitry, detected in humans, dolphins, bats and some birds. The lack of common ancestors suggests that the basis for vocal learning has evolved independently through evolutionary convergence.
Animal culture can be an important consideration in conservation management. As of 2020, culture and sociality were included in the aspects of the management framework of the Convention on the Conservation of Migratory Species of Wild Animals (CMS).
Background
Culture
|
https://en.wikipedia.org/wiki/Less-than%20sign
|
The less-than sign is a mathematical symbol that denotes an inequality between two values. The widely adopted form of two equal-length strokes connecting in an acute angle at the left, , has been found in documents dated as far back as the 1560s. In mathematical writing, the less-than sign is typically placed between two values being compared and signifies that the first number is less than the second number. Examples of typical usage include and .
Since the development of computer programming languages, the less-than sign and the greater-than sign have been repurposed for a range of uses and operations.
Computing
The less-than sign, , is an original ASCII character (hex 3C, decimal 60).
Programming
In BASIC, Lisp-family languages, and C-family languages (including Java and C++), comparison operator < means "less than".
In Coldfusion, operator .lt. means "less than".
In Fortran, operator .LT. means "less than"; later versions allow <.
Shell scripts
In Bourne shell (and many other shells), operator -lt means "less than". Less-than sign is used to redirect input from a file. Less-than plus ampersand () is used to redirect from a file descriptor.
Double less-than sign
The double less-than sign, , may be used for an approximation of the much-less-than sign () or of the opening guillemet (). ASCII does not encode either of these signs, though they are both included in Unicode.
In Bash, Perl, and Ruby, operator (where "EOF" is an arbitrary string, but commonly "EOF" denoting "end of file") is used to denote the beginning of a here document.
In C and C++, operator represents a binary left shift.
In the C++ Standard Library, operator , when applied on an output stream, acts as insertion operator and performs an output operation on the stream.
In Ruby, operator acts as append operator when used between an array and the value to be appended.
In XPath the operator returns true if the left operand precedes the right operand in document order; otherwise it retu
|
https://en.wikipedia.org/wiki/Tamil%20radio%20on%20internet
|
Tamil radio on internet has become very popular after the Sri Lankan Tamil national radio started broadcasting their services on the Internet. This new trend has attracted millions of Tamil listeners from all over the world, specially listeners from south India and a commercial service called "Varthaga Sevai" was started. This became a very popular Sri Lankan Tamil radio service and since then other private Tamil radio stations have also started broadcasting.
Early days
The first private Tamil radio station was "Sooryan fm" who also started to stream over the Internet and captured all the Tamil listeners that the Tamil commercial service had built up. Sooryan fm quickly become very popular because of their simple Tamil. Competition for Tamil radio increased when several private Tamil radios started (Shakthi, Thalam, etc.). After Shakthi entered into Tamil TV the trend slightly changed away from radio and into television with the generation change.
Internet radio
With the introduction of Internet radio, there were no Tamil-language stations with live announcers and programmes but there were and still are many Tamil stations broadcasting only Tamil songs. The first Internet station which was very famous for broadcasting only songs was "Superstarzfm". This ceased broadcasting after a while due to financial problems. Later, some young people with SObrothers joined and created the radio station "TamilsFlashFm", which is also known as TFFm. This is the first Tamil Youth Internet radio and within three years it had become very popular and reached monthly 60,000 Tamil Listeners worldwide. This station not only broadcast songs round the clock but also hosted live on air shows with young Rj's giving the listeners the chance to request songs through Skype and MSN. The current Program Manager of TamilFlash.Fm is Sabesan Kanagaratnam.
Other radio stations followed TamilsFlashFm's lead and produced live shows on air.
Now there are other Internet radio stations which use the SH
|
https://en.wikipedia.org/wiki/Negroponte%20switch
|
The Negroponte Switch is an idea developed by Nicholas Negroponte in the 1980s, while at the Media Lab at MIT. He suggested that due to the accidents of engineering history we had ended up with static devices – such as televisions – receiving their content via signals travelling over the airways, while devices that could have been mobile and personal – such as telephones – were receiving their content over static cables. It was his idea that a better use of available communication resource would result if the information, (such as phone calls). going through the cables was to go through the air, and that going through the air (such as TV programmes) would be delivered via cables. Negroponte called this process “trading places”.
At an event organized by Northern Telecom, his co-presenter George Gilder called it the “Negroponte Switch”, and that name stuck from then on. As mobile devices came about, connections were needed for the data network, and bandwidths were required and deliverable in wired or fibre-optic systems growth. It became less sensible to use wireless broadcast to communicate with static installations. At some point the switch took place, as limited radio bandwidth was reallocated to data services for mobile equipment, and television and other media moved to cable.
Influence on internet advocacy
Cory Doctorow, author and Electronic Frontier Foundation activist, described the process of the switch as unwiring. He framed this as a move away from a global internetwork, which passes through many chokepoints where data may be controlled and inspected, toward one which uses available bandwidth frugally by passing communications in a mesh and avoiding chokepoints. He and Charles Stross wrote a short story on the process, called Unwirer.
The description of the switch in terms of a blend of civil liberty and technology was part of an effort to reimplement the Internet in the interests of the users, freedom and democracy.
Influences for change to dig
|
https://en.wikipedia.org/wiki/Ub-AMC
|
Ubiquitin-AMC is a fluorogenic substrate for a wide range of deubiquitinating enzymes (DUBs), including ubiquitin C-terminal hydrolases (UCHs) and ubiquitin specific proteases (USPs). It is a particularly useful reagent for the study of deubiquitinating activity where detection sensitivity or continuous monitoring of activity is essential.
Background
Ubiquitin-AMC is prepared by the C-terminal derivatization of ubiquitin with 7-amino-4-methylcoumarin and has been shown to be a useful and sensitive fluorogenic substrate for wide range of deubiquitinylating enzymes (DUBs), including ubiquitin C-terminal hydrolases (UCHs) and ubiquitin specific proteases (USPs).
Ubiquitin-AMC has been shown to be a sensitive substrate for UCH-L3 (Km = 0.039µM) and for Isopeptidase-T (Km = 0.17-1.4µM), and is particularly useful for studying deubiquitinylating activity where detection sensitivity or continuous monitoring of activity is essential.
Typical assay set-up: Assay substrate concentration: 0.01-1.0µM. Enzyme concentrations, UCH-L3: 10-100pM, isopeptidase-T: 10-100nM. Release of AMC fluorescence by DUB enzymes can be monitored using 380 nm excitation and 460 nm emission wavelengths.
Uses
Substrate for deubiquitinylating enzyme activity assays.
Identification/confirmation of enzyme deubiquitinylation activity.
Investigation of deconjugating enzyme substrate specificity in comparison with alternative UBL-AMC substrates (e.g. NEDD8-AMC)
|
https://en.wikipedia.org/wiki/Johnny%20Reb
|
Johnny Reb is the national personification of the common soldier of the Confederacy. During the American Civil War and afterwards, Johnny Reb and his Union counterpart Billy Yank were used in speech and literature to symbolize the common soldiers who fought in the Civil War in the 1860s. The symbolic image of Johnny Reb in Southern culture has been represented in its novels, poems, art, public statuary, photography, and written history. According to the historian Bell I. Wiley, who wrote about the common soldiers of the Northern and the Southern armies, the name appears to have its origins in the habit of Union soldiers calling out, "Hello, Johnny" or "Howdy, Reb" to Confederate soldiers on the other side of the picket line.
Johnny Reb is often pictured as a Confederate soldier in gray wool uniform with the typical kepi-style forage cap made of wool broadcloth or cotton jean cloth with a rounded, flat top, cotton lining, and leather visor. He is often shown as well with his weapons or with the Confederate flag, sometimes both.
Johnny Reb has been used as a nickname for veteran Confederate soldiers, as well as to refer to white natives of the states that formerly belonged to the Confederacy. The sobriquet is still commonly used in scholarly writing by Southern and Northern authors; for example, Robert N. Rosen, a Jewish native of South Carolina who has written extensively about the roles Southern Jews played in the Confederate States Army, refers to "Jewish Johnny Rebs". The term Johnny Reb is still sometimes used in popular writing and in news media. In 2000, The Los Angeles Times published an article by the historian Eric Foner entitled, Chief Johnny Reb, in reference to Jefferson Davis, the Confederate president. A 2018 book review by historian Drew Gilpin Faust appeared in The Wall Street Journal under the title Billy Yank and Johnny Reb.
Use in media
"Johnny Reb" is a Confederate soldier's song written in 1959 by Merle Kilgore and popularized by Johnny Hort
|
https://en.wikipedia.org/wiki/ISO%20128
|
ISO 128 is an international standard (ISO), about the general principles of presentation in technical drawings, specifically the graphical representation of objects on technical drawings.
Overview
Since 2003 the ISO 128 standard contains fifteen parts, which were initiated between 1996 and 2003. It starts with a summary of the general rules for the execution and structure of technical drawings. Further it describes basic conventions for lines, views, cuts and sections, and different types of engineering drawings, such as those for mechanical engineering, architecture, civil engineering, and shipbuilding. It is applicable to both manual and computer-based drawings, but it is not applicable to three-dimensional CAD models.
The ISO 128 replaced the previous DIN 6 standard for drawings, projections and views, which was first published in 1922 and updated in 1950 and 1968. ISO 128 itself was first published in 1982, contained 15 pages and "specified the general principles of presentation to be applied to technical drawings following the orthographic projection methods".
Several parts of this standard have been updated individually. The last parts and the standard as a whole were withdrawn by the ISO in 2001.
A thirteenth part was added in 2013.
Composition of ISO 128
The 7 parts of the ISO 128 standard are:
ISO 128-1:2020 Technical product documentation (TPD) — General principles of representation — Part 1: Introduction and fundamental requirements
ISO 128-2:2020 Technical product documentation (TPD) — General principles of representation — Part 2: Basic conventions for lines
ISO 128-3:2022 Technical product documentation (TPD) — General principles of representation — Part 3: Views, sections and cuts
ISO 128-15:2013 Technical product documentation (TPD) — General principles of presentation — Part 15: Presentation of shipbuilding drawings
ISO/TS 128-71:2010 Technical product documentation (TPD) — General principles of presentation — Part 71: Simplified repres
|
https://en.wikipedia.org/wiki/Ronald%20C.%20Read
|
Ronald Cedric Read (19 December 1924 – 7 January 2019) was a British mathematician, latterly a professor emeritus of mathematics at the University of Waterloo, Canada. He published many books and papers, primarily on enumeration of graphs, graph isomorphism, chromatic polynomials, and particularly, the use of computers in graph-theoretical research. A majority of his later work was done in Waterloo.
Read received his Ph.D. (1959) in graph theory from the University of London.
Life and career
Ronald Read served in the Royal Navy during World War II, then completed a degree in mathematics at the University of Cambridge before joining the University College of the West Indies (later the University of the West Indies) in Jamaica as the second founding member of the Mathematics Department there. In 1970 he moved his family to Canada to take up a post as Professor of Mathematics at the University of Waterloo, Ontario, Canada.
While in Jamaica he became interested in cave exploration, and in 1957 he founded the Jamaica Caving Club.
He had a lifelong interest in the making of string figures and is the inventor of the .
He was an accomplished musician and played many instruments including violin, viola, cello, double bass, piano, guitar, lute, and many early music instruments, some of which he also built. He had diplomas in Theory and in Composition from the Royal Conservatory of Music in Toronto, Canada, and composed four works for orchestra and several pieces for smaller groups. Read died in January 2019 at the age of 94.
Selected papers
An Introduction to Chromatic Polynomials. Journal of Combinatorial Theory 4 (1968) 52 - 71.
Every One A Winner; or How to avoid isomorphism search when cataloguing combinatorial configurations. Annals of Discrete Mathematics 2, North-Holland Publishing Company (1978) 107-120.
(With P. Rosenstiehl) On the Principal Edge Tripartition of a Graph. Annals of Discrete Mathematics 3, North-Holland Publishing Company, (1978) 195-226.
(Wit
|
https://en.wikipedia.org/wiki/California%20sea%20hare
|
The California sea hare (Aplysia californica) is a species of sea slug in the sea hare family, Aplysiidae. It is found in the Pacific Ocean, off the coast of California in the United States and northwestern Mexico.
Distribution
A. californica is found along the coast of California, United States, and northwestern Mexico (including the Gulf of California). Aplysia species inhabit the photic zone to graze on algae, mainly the intertidal, usually not deeper than .
Description
The maximum length recorded for the California sea hare is when crawling, thus fully extended, although most adult specimens are half this size or smaller. Adult animals can weigh up to . A closely related species, Aplysia vaccaria, the black sea hare, can grow to be larger still.
A California sea hare is typically reddish-brown to greenish-brown, but the color varies based on the algae it ingests. Each sea hare houses four tentacles, with two on the head sheltering the eyes, and two on the face surrounding the mouth. The body has two folds, called parapodia, which envelop the gills for protection but enable water to get by. Below the body is a muscle that allows for mobility, almost like a foot. The California sea hare also has an internal shell to protect its organs.
Lifecycle
Like all sea hares, the California sea hare is hermaphroditic, acting as male and female simultaneously during mating. A. californica is known to form mating chains with up to 20 animals. The eggs are yellow-green, and change after 8–9 days into a brown color before larvae hatch. Mating is most prominent during the summer following the rise of the water temperature to 17 °C.
A. californica has a generation time of 19 weeks: Days 1-37 after hatching from the egg comprise the planktonic stage, days 34-37 are the metamorphic stage, and days 45-80 are the juvenile stage. At about day 30, the larvae move on from the planktonic stage and begin to roost on algae, typically red algae. The larvae eat enough to double their w
|
https://en.wikipedia.org/wiki/Bernstein%E2%80%93Sato%20polynomial
|
In mathematics, the Bernstein–Sato polynomial is a polynomial related to differential operators, introduced independently by and , . It is also known as the b-function, the b-polynomial, and the Bernstein polynomial, though it is not related to the Bernstein polynomials used in approximation theory. It has applications to singularity theory, monodromy theory, and quantum field theory.
gives an elementary introduction, while and give more advanced accounts.
Definition and properties
If is a polynomial in several variables, then there is a non-zero polynomial and a differential operator with polynomial coefficients such that
The Bernstein–Sato polynomial is the monic polynomial of smallest degree amongst such polynomials . Its existence can be shown using the notion of holonomic D-modules.
proved that all roots of the Bernstein–Sato polynomial are negative rational numbers.
The Bernstein–Sato polynomial can also be defined for products of powers of several polynomials . In this case it is a product of linear factors with rational coefficients.
generalized the Bernstein–Sato polynomial to arbitrary varieties.
Note, that the Bernstein–Sato polynomial can be computed algorithmically. However, such computations are hard in general. There are implementations of related algorithms in computer algebra systems RISA/Asir, Macaulay2, and SINGULAR.
presented algorithms to compute the Bernstein–Sato polynomial of an affine variety together with an implementation in the computer algebra system SINGULAR.
described some of the algorithms for computing Bernstein–Sato polynomials by computer.
Examples
If then
so the Bernstein–Sato polynomial is
If then
so
The Bernstein–Sato polynomial of x2 + y3 is
If tij are n2 variables, then the Bernstein–Sato polynomial of det(tij) is given by
which follows from
where Ω is Cayley's omega process, which in turn follows from the Capelli identity.
Applications
If is a non-negative polynomial then , initially
|
https://en.wikipedia.org/wiki/Limiting%20factor
|
A limiting factor is a variable of a system that causes a noticeable change in output or another measure of a type of system. The limiting factor is in a pyramid shape of organisms going up from the producers to consumers and so on. A factor not limiting over a certain domain of starting conditions may yet be limiting over another domain of starting conditions, including that of the factor.
Overview
The identification of a factor as limiting is possible only in distinction to one or more other factors that are non-limiting. Disciplines differ in their use of the term as to whether they allow the simultaneous existence of more than one limiting factor which (may then be called "co-limiting"), but they all require the existence of at least one non-limiting factor when the terms are used. There are several different possible scenarios of limitation when more than one factor is present. The first scenario, called single limitation occurs when only one factor, the one with maximum demand, limits the System. Serial co-limitation is when one factor has no direct limiting effects on the system, but must be present to increase the limitation of a second factor. A third scenario, independent limitation, occurs when two factors both have limiting effects on the system but work through different mechanisms. Another scenario, synergistic limitation, occurs when both factors contribute to the same limitation mechanism, but in different ways.
In 1905 Frederick Blackman articulated the role of limiting factors as follows: "When a process is conditioned as to its rapidity by several separate factors the rate of the process is limited by the pace of the slowest factor." In terms of the magnitude of a function, he wrote, "When the magnitude of a function is limited by one of a set of possible factors, increase of that factor, and of that one alone, will be found to bring about an increase of the magnitude of the function."
Ecology
In population ecology, a regulating factor, al
|
https://en.wikipedia.org/wiki/Orthogonality%20%28programming%29
|
In computer programming, orthogonality means that operations change just one thing without affecting others. The term is most-frequently used regarding assembly instruction sets, as orthogonal instruction set.
Orthogonality in a programming language means that a relatively small set of primitive constructs can be combined in a relatively small number of ways to build the control and data structures of the language. It is associated with simplicity; the more orthogonal the design, the fewer exceptions. This makes it easier to learn, read and write programs in a programming language. The meaning of an orthogonal feature is independent of context; the key parameters are symmetry and consistency (for example, a pointer is an orthogonal concept).
An example from IBM Mainframe and VAX highlights this concept. An IBM mainframe has two different instructions for adding the contents of a register to a memory cell (or another register). These statements are shown below:
A Reg1, memory_cell
AR Reg1, Reg2
In the first case, the contents of Reg1 are added to the contents of a memory cell; the result is stored in Reg1. In the second case, the contents of Reg1 are added to the contents of another register (Reg2) and the result is stored in Reg1.
In contrast to the above set of statements, VAX has only one statement for addition:
ADDL operand1, operand2
In this case the two operands (operand1 and operand2) can be registers, memory cells, or a combination of both; the instruction adds the contents of operand1 to the contents of operand2, storing the result in operand1.
VAX's instruction for addition is more orthogonal than the instructions provided by IBM; hence, it is easier for the programmer to remember (and use) the one provided by VAX.
The Revised Report on the Algorithmic Language Algol 68 had this to say about "Orthogonal design":
The design of C language may be examined from the perspective of orthogonality. The C language is somewhat inconsistent in its treatmen
|
https://en.wikipedia.org/wiki/Alpha%2021264
|
The Alpha 21264 is a Digital Equipment Corporation RISC microprocessor launched on 19 October 1998. The 21264 implemented the Alpha instruction set architecture (ISA).
Description
The Alpha 21264 is a four-issue superscalar microprocessor with out-of-order execution and speculative execution. It has a peak execution rate of six instructions per cycle and could sustain four instructions per cycle. It has a seven-stage instruction pipeline.
Out of order execution
At any given stage, the microprocessor could have up to 80 instructions in various stages of execution, surpassing any other contemporary microprocessor.
Decoded instructions are held in instruction queues and are issued when their operands are available. The integer queue contained 20 entries and the floating-point queue 15. Each queue could issue as many instructions as there were pipelines.
Ebox
The Ebox executes integer, load and store instructions. It has two integer units, two load store units and two integer register files. Each integer register file contained 80 entries, of which 32 are architectural registers, 40 are rename registers and 8 are PAL shadow registers. There was no entry for register R31 because in the Alpha architecture, R31 is hardwired to zero and is read-only.
Each register file served an integer unit and a load store unit, and the register file and its two units are referred to as a "cluster". The two clusters were designated U0 and U1. This scheme was used as it reduced the number of write and read ports required to serve operands and receive results, thus reducing the physical size of the register file, enabling the microprocessor to operate at higher clock frequencies. Writes to any of the register files thus have to be synchronized, which required a clock cycle to complete, negatively impacting performance by one percent. The reduction of performance resulting from the synchronization was compensated in two ways. Firstly, the higher clock frequency achievable offset the
|
https://en.wikipedia.org/wiki/Metaprogramming
|
Metaprogramming is a programming technique in which computer programs have the ability to treat other programs as their data. It means that a program can be designed to read, generate, analyze or transform other programs, and even modify itself while running. In some cases, this allows programmers to minimize the number of lines of code to express a solution, in turn reducing development time. It also allows programs a greater flexibility to efficiently handle new situations without recompilation.
Metaprogramming can be used to move computations from run-time to compile-time, to generate code using compile time computations, and to enable self-modifying code. The ability of a programming language to be its own metalanguage is called reflection. Reflection is a valuable language feature to facilitate metaprogramming.
Metaprogramming was popular in the 1970s and 1980s using list processing languages such as LISP. LISP hardware machines were popular in the 1980s and enabled applications that could process code. They were frequently used for artificial intelligence applications.
Approaches
Metaprogramming enables developers to write programs and develop code that falls under the generic programming paradigm. Having the programming language itself as a first-class data type (as in Lisp, Prolog, SNOBOL, or Rebol) is also very useful; this is known as homoiconicity. Generic programming invokes a metaprogramming facility within a language by allowing one to write code without the concern of specifying data types since they can be supplied as parameters when used.
Metaprogramming usually works in one of three ways.
The first approach is to expose the internals of the run-time engine to the programming code through application programming interfaces (APIs) like that for the .NET IL emitter.
The second approach is dynamic execution of expressions that contain programming commands, often composed from strings, but can also be from other methods using arguments or conte
|
https://en.wikipedia.org/wiki/Lazy%20linear%20hybrid%20automaton
|
Lazy linear hybrid automata model the discrete time behavior of control systems containing finite-precision sensors and actuators interacting with their environment under bounded inertial delays. The model permits only linear flow constraints but the invariants and guards can be any computable function.
This computational model was proposed by Manindra Agrawal and P. S. Thiagarajan. This model is more realistic and also computationally amenable than the currently popular modeling paradigm of linear hybrid automaton.
External links
Formalization and theory behind the model
Reachability Analysis of Lazy Linear Hybrid Automata Research
Automata (computation)
Models of computation
|
https://en.wikipedia.org/wiki/Actinorhizal%20plant
|
Actinorhizal plants are a group of angiosperms characterized by their ability to form a symbiosis with the nitrogen fixing actinomycetota Frankia. This association leads to the formation of nitrogen-fixing root nodules.
Classification
Actinorhizal plants are dicotyledons distributed among three angiosperm orders, 8 families and 25 genera:
These three orders form a single clade within the Rosids, which is a sister taxon to the other major nitrogen-fixing order, the Fabales. All actinorhizal species are trees or shrubs, except for the genus Datisca.
Many are common plants in temperate regions like alder, bayberry, sweetfern, Avens, mountain misery and Coriaria. Some Elaeagnus species and Sea-buckthorns produce edible fruit. In tropical regions, Casuarinas are widely cultivated.
Distribution and ecology
Actinorhizal plants are found on all continents except for Antarctica. Their ability to form nitrogen-fixing nodules confers a selective advantage in poor soils. Most actinorhizal plants are therefore pioneer species that colonize young soils where available nitrogen is scarce, such as moraines, volcanic flows or sand dunes. Being among the first species to colonize these disturbed environments, actinorhizal shrubs and trees play a critical role, enriching the soil and enabling the establishment of other species in an ecological succession. Actinorhizal plants like alders are also common in the riparian forest.
Actinorhizal plants are the major contributors to nitrogen fixation in broad areas of the world, and are particularly important in temperate forest. The nitrogen fixation rate measured for some alder species is as high as 300 kg of N2/ha/year, close to the highest rate reported in legumes.
Evolutionary origin
No fossil records are available concerning nodules, but fossil pollen of plants similar to modern actinorhizal species has been found in sediments deposited 87 million years ago. The origin of the symbiotic association remains uncertain. The ability t
|
https://en.wikipedia.org/wiki/KDE%20Gear
|
The KDE Gear (also known as the KDE Applications Bundle or KDE Applications) is a set of applications and supporting libraries that are developed by the KDE community, primarily used on Linux-based operating systems but mostly multiplatform, and released on a common release schedule.
The bundle is composed of over 100 applications. Examples of prominent applications in the bundle include the file manager Dolphin, document viewer Okular, text editor Kate, archiving tool Ark and terminal emulator Konsole.
Previously the KDE Applications Bundle was part of the KDE Software Compilation.
Extragear
Software that is not part of the official KDE Applications bundle can be found in the "Extragear" section. They release on their own schedule and feature their own versioning numbers. There are many standalone applications like KTorrent, Krita or Amarok that are mostly designed to be portable between operating systems and deployable independent of a particular workspace or desktop environment. Some brands consist of multiple applications, such as Calligra Office Suite or KDE Kontact. There are several options for obtaining and installing KDE applications under Linux. Moreover, most of the KDE platform and applications have been ported to OpenBSD and NetBSD. While prior editions of KDE were often seen on other flavors of Unix, such as Solaris the popularity of the open source alternatives running on a wide range of hardware (having been ported to nearly every RISC and x86 64 processors) has made KDE projects on similar OSs less obvious.
List of applications part of the bundle
Development
Software development
KDE SDK is a collection of two dozen distinct integrated (both within the SDK but also with other KDE applications, e.g. many work with Dolphin, the default file manager) applications and components that work with/are part of KDevelop, and is suitable for general purpose software development in a range of languages. It provides the tooling used to engineer KDE, an
|
https://en.wikipedia.org/wiki/PAM%20%28cooking%20oil%29
|
PAM is a cooking spray currently owned and distributed by ConAgra Foods. Its main ingredient is canola oil.
PAM was introduced in 1959 by Leon Rubin who, with Arthur Meyerhoff, started PAM Products, Inc. to market the spray. The name PAM is an acronym for Product of Arthur Meyerhoff. In 1971, Gibraltar Industries merged with American Home Products (now Wyeth) and became part of the Boyle-Midway portfolio. When Reckitt & Colman (now Reckitt Benckiser) acquired Boyle-Midway from American Home Products in 1990, PAM became part of the American Home Foods subsidiary. In 1996, AHF was acquired from American Home Products by Hicks, Muse, Tate & Furst and C. Dean Metropoulos & Company, becoming International Home Foods, which in turn was acquired by ConAgra in 2000.
PAM is marketed in various flavors, such as butter and olive oil, meant to impart the flavor of cooking with those ingredients. Flavors such as lemon or garlic are also offered. PAM also markets high-temperature sprays formulated for use when grilling etc., and one containing flour suitable for dry-cooking as in baking. PAM is marketed as a nominally zero-calorie alternative to other oils used as lubricants when using cooking methods such as sauteing or baking (US regulations allow food products to claim to be zero-calorie if they contain fewer than 5 calories per Reference Amount Customarily Consumed and per labeled serving, and the serving size of a second spray is only 0.3 g containing about 2 calories.) Similar sprays are offered by other manufacturers.
|
https://en.wikipedia.org/wiki/Osteitis%20pubis
|
Osteitis pubis is a noninfectious inflammation of the pubis symphysis (also known as the pubic symphysis, symphysis pubis, or symphysis pubica), causing varying degrees of lower abdominal and pelvic pain. Osteitis pubis was first described in patients who had undergone suprapubic surgery, and it remains a well-known complication of invasive procedures about the pelvis. It may also occur as an inflammatory process in athletes. The incidence and cause of osteitis pubis as an inflammatory process versus an infectious process continues to fuel debate among physicians when confronted by a patient who presents complaining of abdominal pain or pelvic pain and overlapping symptoms. It was first described in 1924.
Signs and symptoms
The symptoms of osteitis pubis can include loss of flexibility in the groin region, dull aching pain in the groin, or in more severe cases, a sharp stabbing pain when running, kicking, changing directions, or even during routine activities such as standing up or getting out of a car. Tenderness on palpation is also commonly present in the adductor longus origin.
Causes
Pregnancy/childbirth
Gynecologic surgery
Urologic surgery
Athletic activities (e.g. running, football, American football, ice hockey, tennis)
Major trauma
Repeated minor trauma
Rheumatological disorders
Unknown cause
In the pre-antibiotic era, osteitis pubis was an occasional complication of pelvic surgery, and in particular, of retropubic prostatectomy.
Overload or training errors
Exercising on hard surfaces (like concrete)
Exercising on uneven ground
Beginning an exercise program after a long lay-off period
Increasing exercise intensity or duration too quickly
Exercising in worn out or ill-fitting shoes
Biomechanical inefficiencies
Faulty foot and body mechanics and gait disturbances
Poor running or walking mechanics
Tight, stiff muscles in the hips, groin, and buttocks
Muscular imbalances
Leg length differences
Diagnosis
Osteitis pubis may be diagnosed with an X
|
https://en.wikipedia.org/wiki/10%2C000
|
10,000 (ten thousand) is the natural number following 9,999 and preceding 10,001.
Name
Many languages have a specific word for this number: in Ancient Greek it is (the etymological root of the word myriad in English), in Aramaic , in Hebrew [], in Chinese (Mandarin , Cantonese , Hokkien bān), in Japanese [], in Khmer [], in Korean [], in Russian [], in Vietnamese , in Sanskrit अयुत [ayuta], in Thai [], in Malayalam [], and in Malagasy alina. In many of these languages, it often denotes a very large but indefinite number.
The classical Greeks used letters of the Greek alphabet to represent Greek numerals: they used a capital letter mu (Μ) to represent ten thousand. This Greek root was used in early versions of the metric system in the form of the decimal prefix myria-.
The Number ten thousand can also be written as 10,000 (U.K. and U.S.), 10,000 (Central America and South America, as well as mainland Europe), 10,000 (transition metric), or 10,000 (with the dot raised to the middle of the zeroes; metric).
In mathematics
In scientific notation it is written as 104 or 1 E+4 (equivalently 1 E4) in E notation.
It is the square of 100 and the square root of 100,000,000.
The value of a myriad to the power of itself, 1000010000 = 1040000.
It has a total of 25 divisors, whose geometric mean averages a whole number, 100.
It has a reduced totient of 500, and a totient of 4,000, with a total of 16 integers having a totient value of 10,000.
There are a total of 1,229 prime numbers less than ten thousand, a count that is itself prime.
A myriagon is a polygon with ten thousand edges and a total of 25 dihedral symmetry groups when including the myriagon itself, alongside 25 cyclic groups as subgroups.
In science
In astronomy,
asteroid Number: 10000 Myriostos, Provisional Designation: , Discovery Date: September 30, 1951, by A. G. Wilson:List of asteroids (9001-10000).
In climate, Summary of 10000 Years is one of several pages of the Climate Timeline Tool
|
https://en.wikipedia.org/wiki/Reef%20burials
|
Reef burials are a type of "green" or "natural" burial considered by some to be an eco-friendly alternative to traditional burial. Cremation ash is mixed with concrete to form objects that are placed on the seafloor to encourage wildlife in areas where sea life has been diminished.
Background
Reef burials are a new burial practice gaining a degree of popularity. Rather than being buried in the earth, a person's remains are cremated and the resulting ash is mixed with pH-balanced concrete to create structures which are placed on the seabed to help restore marine habitats similar to a coral reef. The concrete is mixed using fibreglass rather than metal, so that it does not rust and has the same pH balance as the sea. In areas where the seafloor or coral reefs have been destroyed the structures help to renew the sea-life by establishing new habitats for fish and crustaceans. The structures are expected to last for 500 years and are variously perforated domes called "reef balls", pyramids, or similar memorial-style shapes chosen to be appropriate to the location. Reef balls weigh between and their perforations ensure that storm pressure doesn't move them out of place on the sea floor.
Reef burials are popular amongst divers and others who love the sea. Some people feel that such burials offer the deceased a second life as part of a living reef. Loved ones are given the GPS coordinates of the resting place so that they dive to visit the site of the remains. A memorial plaque is installed with the person's name, date of birth and death. Thousands of reef balls are put into oceans each year. Large reef memorials can accommodate multiple sets of remains, so that families can be included and placed together.
Locations
In the United States there are more than thirty permitted locations for reef memorials, including off the coasts of Florida at Mexico Beach, Egg Harbor, near Atlantic City, New Jersey and Texas. In the UK, where the Crown Estate owns the UK seabed, a
|
https://en.wikipedia.org/wiki/Petrie%20Prize%20Lecture
|
The Petrie Prize Lecture is an award given in alternate years by the Canadian Astronomical Society to an outstanding astrophysicist. The award commemorates the contributions to astrophysical research of the Canadian astronomer Robert M. Petrie.
Prize Winners
Source: Canadian Astronomical Society
1970 Alastair G. W. Cameron
1971 Jesse Leonard Greenstein
1971 Carlyle Smith Beals
1977 J. Beverley Oke
1979 Geoffrey Burbidge
1981 Hubert Reeves
1983 M. J. Plavec
1985 Charles Hard Townes
1987 Henry Matthews
1989 James Peebles
1991 Peter B. Stetson
1993 Maarten Schmidt
1995 George Howard Herbig
1997 Alexei Filippenko
1999 Sidney van den Bergh
2001 James E. Gunn
2003 Martin Rees
2005 Reinhard Genzel
2007 Ewine van Dishoeck
2009 Scott Tremaine
2011 Andrew Fabian
2013 Françoise Combes
2015 Wendy Freedman
2017 Charles A. Beichman
2019 Gabriela Gonzalez
2021 Heino Falke
2023 You-Hua Chu
See also
List of astronomy awards
|
https://en.wikipedia.org/wiki/Single-cell%20variability
|
In cell biology, single-cell variability occurs when individual cells in an otherwise similar population differ in shape, size, position in the cell cycle, or molecular-level characteristics. Such differences can be detected using modern single-cell analysis techniques. Investigation of variability within a population of cells contributes to understanding of developmental and pathological processes,
Single-cell analysis
A sample of cells may appear similar, but the cells can vary in their individual characteristics, such as shape and size, mRNA expression levels, genome, or individual counts of metabolites. In the past, the only methods available for investigating such properties required a population of cells and provided an estimate of the characteristic of interest, averaged over the population, which could obscure important differences among the cells. Single-cell analysis allows scientists to study the properties of a single cell of interest with high accuracy, revealing individual differences among populations and offering new insights in molecular biology. These individual differences are important in fields such as developmental biology, where individual cells can take on different "fates" - become specialized cells such as neurons or organ tissue - during the growth of an embryo; in cancer research, where individual malignant cells can vary in their response to therapy; or in infectious disease, where only a subset of cells in a population become infected by a pathogen.
Population-level views of cells can offer a distorted view of the data by averaging out the properties of distinct subsets of cells. For example, if half the cells of a particular group are expressing high levels of a given gene, and the rest are expressing low levels, results from a population-wide analysis may appear as if all cells are expressing a medium level of the given gene. Thus, single-cell analysis allows researchers to study biological processes in finer detail and answer ques
|
https://en.wikipedia.org/wiki/CLASS%20B1359%2B154
|
CLASS B1359+154 is a quasar, or quasi-stellar object, that has a redshift of 3.235. A group of three foreground galaxies at a redshift of about 1 are behaving as gravitational lenses. The result is a rare example of a sixfold multiply imaged quasar.
See also
Twin Quasar
Einstein Cross
|
https://en.wikipedia.org/wiki/Gal4%20transcription%20factor
|
The Gal4 transcription factor is a positive regulator of gene expression of galactose-induced genes. This protein represents a large fungal family of transcription factors, Gal4 family, which includes over 50 members in the yeast Saccharomyces cerevisiae e.g. Oaf1, Pip2, Pdr1, Pdr3, Leu3.
Gal4 recognizes genes with UAS, an upstream activating sequence, and activates them. In yeast cells, the principal targets are GAL1 (galactokinase), GAL10 (UDP-glucose 4-epimerase), and GAL7 (galactose-1-phosphate uridylyltransferase), three enzymes required for galactose metabolism. This binding has also proven useful in constructing the GAL4/UAS system, a technique for controlling expression in insects. In yeast, Gal4 is by default repressed by Gal80, and activated in the presence of galactose as Gal3 binds away Gal80.
Domains
Two executive domains, DNA binding and activation domains, provide key function of the Gal4 protein conforming to most of the transcription factors.
DNA binding
Gal4 N-terminus is a zinc finger and belongs to the Zn(2)-C6 fungal family. It forms a Zn – cysteines thiolate cluster, and specifically recognizes UAS in GAL1 promoter.
Gal4 transactivation
Localised to the C-terminus, belongs to the nine amino acids transactivation domain family, 9aaTAD, together with Oaf1, Pip2, Pdr1, Pdr3, but also p53, E2A, MLL.
Regulation
Galactose induces Gal4 mediated transcription albeit Glucose causes severe repression.
As a part of the Gal4 regulation, inhibitory protein Gal80 recognises and binds to the Gal4 region (853-874 aa).
The inhibitory protein Gal80 is sequestered by regulatory protein Gal3 in Galactose dependent manner. This allows for Gal4 to work when there is galactose.
Mutants
The Gal4 loss-of-function mutant gal4-64 (1-852 aa, deletion of the Gal4 C-terminal 29 aa) lost both interaction with Gal80 and activation function.
In the Gal4 reverted mutant Gal4C-62 mutant, a sequence (QTAY N AFMN) with the 9aaTAD pattern emerged and restored activati
|
https://en.wikipedia.org/wiki/Mammotome
|
Mammotome is a Cincinnati, OH based company who pioneered a vacuum-assisted breast biopsy (VAC) device that uses image guidance such as x-ray, ultrasound and/or MRI to perform breast biopsies. A biopsy using a Mammotome® device can be done on an outpatient basis with a local anesthetic. The Mammotome brand is sold in over 45 different countries throughout the world.
Indications
A stereotaxic macro-biopsy is often indicated after suspicious elements are seen on a mammography (mass, micro-calcifications or focal abnormal changes in the tissues). It is always used to analyse those elements but can sometimes also remove it completely. It is often used when:
The mammography shows a suspicious solid mass.
The mammography shows a suspicious "islet" of micro-calcifications.
The breast tissue seems deformed.
A new mass or micro-calcification islet is spotted in a zone previously targeted by surgery.
Risks associated with the procedure
Side effects:
Common: bruising, mild discomfort during the procedure, mild bleeding and tenderness at the biopsy site.
Rare: significant bleeding or pain during biopsy, significant tenderness and bleeding at the biopsy site.
Complications:
Rare: Post-biopsy breast infection. Allergic reaction to the local anaesthetic.
Complications from biopsies can delay subsequent breast surgery.
The procedure may, rarely, fail due to inaccurate sampling of the lesion; results may underestimate the severity of the lesion although these risks do not differ from other biopsy or surgical procedures. Occasionally, even after a successful biopsy, the diagnosis may remain uncertain and require a surgical biopsy, especially when atypical or precancerous cells are found on core biopsy.
Limitations of the procedure
Lesions accompanied by diffuse calcium deposits scattered throughout the breast or located near the chest wall are difficult to target or evaluate by stereotactic biopsy. If the mammogram shows only a vague change in tissue density but no defini
|
https://en.wikipedia.org/wiki/Tarski%E2%80%93Seidenberg%20theorem
|
In mathematics, the Tarski–Seidenberg theorem states that a set in (n + 1)-dimensional space defined by polynomial equations and inequalities can be projected down onto n-dimensional space, and the resulting set is still definable in terms of polynomial identities and inequalities. The theorem—also known as the Tarski–Seidenberg projection property—is named after Alfred Tarski and Abraham Seidenberg. It implies that quantifier elimination is possible over the reals, that is that every formula constructed from polynomial equations and inequalities by logical connectives (or), (and), (not) and quantifiers (for all), (exists) is equivalent to a similar formula without quantifiers. An important consequence is the decidability of the theory of real-closed fields.
Although the original proof of the theorem was constructive, the resulting algorithm has a computational complexity that is too high for using the method on a computer. George E. Collins introduced the algorithm of cylindrical algebraic decomposition, which allows quantifier elimination over the reals in double exponential time. This complexity is optimal, as there are examples where the output has a double exponential number of connected components. This algorithm is therefore fundamental, and it is widely used in computational algebraic geometry.
Statement
A semialgebraic set in Rn is a finite union of sets defined by a finite number of polynomial equations and inequalities, that is by a finite number of statements of the form
and
for polynomials p and q. We define a projection map π : Rn +1 → Rn by sending a point (x1, ..., xn, xn +1) to (x1, ..., xn). Then the Tarski–Seidenberg theorem states that if X is a semialgebraic set in Rn +1 for some n ≥ 1, then π(X) is a semialgebraic set in Rn.
Failure with algebraic sets
If we only define sets using polynomial equations and not inequalities then we define algebraic sets rather than semialgebraic sets. For these sets the theore
|
https://en.wikipedia.org/wiki/Atmospheric%20optics%20ray-tracing%20codes
|
Atmospheric optics ray tracing codes - this article list codes for light scattering using ray-tracing technique to study atmospheric optics phenomena such as rainbows and halos. Such particles can be large raindrops or hexagonal ice crystals. Such codes are one of many approaches to calculations of light scattering by particles.
Geometric optics (ray tracing)
Ray tracing techniques can be applied to study light scattering by spherical and non-spherical particles under the condition that the size of a particle is much larger than the wavelength of light. The light can be considered as collection of separate rays with width of rays much larger than the wavelength but smaller than a particle. Rays hitting the particle undergoes reflection, refraction and diffraction. These rays exit in various directions with different amplitudes and phases. Such ray tracing techniques are used to describe optical phenomena such as rainbow of halo on hexagonal ice crystals for large particles.
Review of several mathematical techniques is provided in series of publications.
The 46° halo was first explained as being caused by refractions through ice crystals in 1679 by the French physicist Edmé Mariotte (1620–1684) in terms of light refraction
Jacobowitz in 1971 was the first to apply the ray-tracing technique to hexagonal ice crystal. Wendling et al. (1979) extended Jacobowitz's work from hexagonal ice particle with infinite length to finite length and combined Monte Carlo technique to the ray-tracing simulations.
Classification
The compilation contains information about the electromagnetic scattering by hexagonal ice crystals, large raindrops, and relevant links and applications.
Codes for light scattering by hexagonal ice crystals
Relevant scattering codes
Discrete dipole approximation codes
Codes for electromagnetic scattering by cylinders
Codes for electromagnetic scattering by spheres
External links
Scatterlib - Google Code repository of light scattering codes
See
|
https://en.wikipedia.org/wiki/Digital%20signature%20forgery
|
In a cryptographic digital signature or MAC system, digital signature forgery is the ability to create a pair consisting of a message, , and a signature (or MAC), , that is valid for , but has not been created in the past by the legitimate signer. There are different types of forgery.
To each of these types, security definitions can be associated. A signature scheme is secure by a specific definition if no forgery of the associated type is possible.
Types
The following definitions are ordered from lowest to highest achieved security, in other words, from most powerful to the weakest attack. The definitions form a hierarchy, meaning that an attacker able to mount a specific attack can execute all the attacks further down the list. Likewise, a scheme that reaches a certain security goal also reaches all prior ones.
Total break
More general than the following attacks, there is also a total break: when adversary can recover the private information and keys used by the signer, they can create any possible signature on any message.
Universal forgery (universal unforgeability, UUF)
Universal forgery is the creation (by an adversary) of a valid signature, , for any given message, . An adversary capable of universal forgery is able to sign messages they chose themselves (as in selective forgery), messages chosen at random, or even specific messages provided by an opponent.
Selective forgery (selective unforgeability, SUF)
Selective forgery is the creation of a message/signature pair by an adversary, where has been chosen by the attacker prior to the attack. may be chosen to have interesting mathematical properties with respect to the signature algorithm; however, in selective forgery, must be fixed before the start of the attack.
The ability to successfully conduct a selective forgery attack implies the ability to successfully conduct an existential forgery attack.
Existential forgery
Existential forgery (existential unforgeability, EUF) is the creation (by
|
https://en.wikipedia.org/wiki/Moduli%20stack%20of%20principal%20bundles
|
In algebraic geometry, given a smooth projective curve X over a finite field and a smooth affine group scheme G over it, the moduli stack of principal bundles over X, denoted by , is an algebraic stack given by: for any -algebra R,
the category of principal G-bundles over the relative curve .
In particular, the category of -points of , that is, , is the category of G-bundles over X.
Similarly, can also be defined when the curve X is over the field of complex numbers. Roughly, in the complex case, one can define as the quotient stack of the space of holomorphic connections on X by the gauge group. Replacing the quotient stack (which is not a topological space) by a homotopy quotient (which is a topological space) gives the homotopy type of .
In the finite field case, it is not common to define the homotopy type of . But one can still define a (smooth) cohomology and homology of .
Basic properties
It is known that is a smooth stack of dimension where is the genus of X. It is not of finite type but locally of finite type; one thus usually uses a stratification by open substacks of finite type (cf. the Harder–Narasimhan stratification), also for parahoric G over curve X see and for G only a flat group scheme of finite type over X see.
If G is a split reductive group, then the set of connected components is in a natural bijection with the fundamental group .
The Atiyah–Bott formula
Behrend's trace formula
This is a (conjectural) version of the Lefschetz trace formula for when X is over a finite field, introduced by Behrend in 1993. It states: if G is a smooth affine group scheme with semisimple connected generic fiber, then
where (see also Behrend's trace formula for the details)
l is a prime number that is not p and the ring of l-adic integers is viewed as a subring of .
is the geometric Frobenius.
, the sum running over all isomorphism classes of G-bundles on X and convergent.
for a graded vector space , provided the series on the right absolut
|
https://en.wikipedia.org/wiki/List%20of%20U.S.%20state%20and%20territory%20flowers
|
This is a list of U.S. state, federal district, and territory flowers.
See also
List of U.S. state trees
Lists of U.S. state insignia
|
https://en.wikipedia.org/wiki/Eukaryotic%20translation%20initiation%20factor%204E%20family
|
In molecular biology, the eukaryotic translation initiation factor 4E family (eIF-4E) is a family of proteins that bind to the cap structure of eukaryotic cellular mRNAs. Members of this family recognise and bind the 7-methyl-guanosine-containing (m7Gppp) cap during an early step in the initiation of protein synthesis and facilitate ribosome binding to an mRNA by inducing the unwinding of its secondary structures. A tryptophan in the central part of the sequence of human eIF-4E seems to be implicated in cap-binding.
Members of this family include EIF4E, EIF4E2, EIF4E3 and EIF4E1B.
|
https://en.wikipedia.org/wiki/Interaction%20cost
|
Interaction cost can comprise work, costs, and other expenses, required to complete a task or interaction. This applies to several categories, including:
Economy: the interaction cost of purchase includes the requirements to complete it and differs in costs for customers and vendors. The method of payment offered may factor into both transaction cost and interaction cost. Reducing steps for customers can be a service offered by the vendor. Interaction costs should be considered when clients choose vendors. Customers prefer to have a choice about their interaction cost. In self-checkout, work is moved to the customer.
Politics: Specific interaction costs can be increased by law for political gains.
User interface: In a computer menu with a graphical user interface, some designs require more clicks from the user in order to make a selection. With a dropdown menu, one click (or touch or hover) may reveal a hidden menu (sub-menu), with a second click required to select the menu option. If the entire menu were displayed all along, as in a navigation bar, only one click would be required, but the menu would occupy more screen space. Sub-menus require even more care from the user to make a desired selection.
Further reading
(German) Klaus Lange and Frank Sippel: Verwaltungsautomation und Bürgerservice: Ansätze zur Aufhebung eines Widerspruchs, Springer, Wiesbaden 1986,
(German) Torsten Blecker: Unternehmung ohne Grenzen: Konzepte, Strategien und Gestaltungsempfehlungen …, Deutscher Universitäts-Verlag 1998, P. 272, 285
|
https://en.wikipedia.org/wiki/Mockery
|
Mockery or mocking is the act of insulting or making light of a person or other thing, sometimes merely by taunting, but often by making a caricature, purporting to engage in imitation in a way that highlights unflattering characteristics. Mockery can be done in a lighthearted and gentle way, but can also be cruel and hateful, such that it "conjures images of corrosion, deliberate degradation, even subversion; thus, 'to laugh at in contempt, to make sport of' (OED)". Mockery appears to be unique to humans, and serves a number of psychological functions, such as reducing the perceived imbalance of power between authority figures and common people. Examples of mockery can be found in literature and the arts.
Etymology and function
The root word mock traces to the Old French mocquer (later moquer), meaning to scoff at, laugh at, deride, or fool, although the origin of mocquer is itself unknown. Labeling a person or thing as a mockery may also be used to imply that it or they are a poor quality or counterfeit version of some genuine other, such as the case in the usages: "mockery of man" or "the trial was a mockery of justice".
Mockery in psychology
Australian linguistics professor Michael Haugh differentiated between teasing and mockery by emphasizing that, while the two do have substantial overlap in meaning, mockery does not connote repeated provocation or the intentional withholding of desires, and instead implies a type of imitation or impersonation where a key element is that the nature of the act places a central importance on the expectation that it not be taken seriously. Specifically in examining non-serious forms of jocular mockery, Haugh summarized the literature on the features of mockery as consisting of the following:
Laughter, especially on the part of the speaker, acting as a cue that others are invited to laugh also
Phonetic practices, such as a "smile voice" and modulating "sing-song" pitch which mark actions "as laughable", denote an exaggerate
|
https://en.wikipedia.org/wiki/Armorial%20of%20Kosovo
|
This is gallery of coats or arms, seals and emblems used by the institutions of Kosovo since 10 June 1999.
National
UNMIK
Governmental
Historical
Military
Historical
Municipal
The Municipalities of Kosovo have each adopted distinct coats or arms, seals or emblems.
District of Ferizaj
District of Gjakova
District of Gjilan
District of Mitrovica
District of Peja
District of Pristina
District of Prizren
Historical
See also
Emblem of Kosovo (Armorial)
Coat of arms of Albania (Armorial)
Albanian heraldry
Flag of Kosovo (List)
Flag of Albania (List)
National symbols of Kosovo
Kosovo
National symbols of Kosovo
|
https://en.wikipedia.org/wiki/Zinc%20finger%20protein%20541
|
Zinc finger protein 541 is a protein that in humans is encoded by the ZNF541 gene.
|
https://en.wikipedia.org/wiki/Horrocks%20bundle
|
In algebraic geometry, Horrocks bundles are certain indecomposable rank 3 vector bundles (locally free sheaves) on 5-dimensional projective space, found by .
|
https://en.wikipedia.org/wiki/Palatine%20glands
|
The palatine glands form a continuous layer on the posterior surface of the mucous membrane of the soft palate and around the uvula. They are pure mucous glands.
|
https://en.wikipedia.org/wiki/Federation%20of%20European%20Biochemical%20Societies
|
The Federation of the European Biochemical Societies, frequently abbreviated FEBS, is an international scientific society promoting activities in biochemistry, molecular biology and related research areas in Europe and neighbouring regions. It was founded in 1964 and includes over 35,000 members across 39 Constituent Societies.
Present activities
FEBS activities include: publishing journals; providing grants for scientific meetings such as an annual Congress, Young Scientists’ Forum and FEBS Advanced Courses; offering travel awards to early-stage scientists to participate in these events; offering research Fellowships for pre- and post-doctoral bioscientists; promoting molecular life science education; encouraging integration of scientists working in economically disadvantaged countries of the FEBS area; and awarding prizes and medals for research excellence. FEBS collaborates with related scientific societies such as its Constituent Societies, the International Union of Biochemistry and Molecular Biology (IUBMB) and the European Molecular Biology Organization (EMBO).
Awards presented by FEBS include the Sir Hans Krebs Medal, the FEBS/EMBO Women in Science Award (presented jointly with EMBO), the Datta medal and the Theodor Bücher medal.
Journals
FEBS publishes four scientific journals: The FEBS Journal, FEBS Letters, Molecular Oncology and FEBS Open Bio. The FEBS Journal was previously entitled the European Journal of Biochemistry. Molecular Oncology and FEBS Open Bio are open-access journals.
See also
List of biochemistry awards
|
https://en.wikipedia.org/wiki/Ordered%20algebra
|
In mathematics, an ordered algebra is an algebra over the real numbers with unit e together with an associated order such that e is positive (i.e. e ≥ 0), the product of any two positive elements is again positive, and when A is considered as a vector space over then it is an Archimedean ordered vector space.
Properties
Let A be an ordered algebra with unit e and let C* denote the cone in A* (the algebraic dual of A) of all positive linear forms on A.
If f is a linear form on A such that f(e) = 1 and f generates an extreme ray of C* then f is a multiplicative homomorphism.
Results
Stone's Algebra Theorem: Let A be an ordered algebra with unit e such that e is an order unit in A, let A* denote the algebraic dual of A, and let K be the -compact set of all multiplicative positive linear forms satisfying f(e) = 1. Then under the evaluation map, A is isomorphic to a dense subalgebra of . If in addition every positive sequence of type l1 in A is order summable then A together with the Minkowski functional pe is isomorphic to the Banach algebra .
See also
Ordered vector space
Riesz space
|
https://en.wikipedia.org/wiki/Uncomputation
|
Uncomputation is a technique, used in reversible circuits, for cleaning up temporary effects on ancilla bits so that they can be re-used.
Uncomputation is a fundamental step in quantum computing algorithms. Whether or not intermediate effects have been uncomputed affects how states interfere with each other when measuring results.
The process is primarily motivated by the principle of implicit measurement., which states that discarding a register during computation is physically equivalent to measuring it. Failure to uncompute garbage registers can have unintentional consequences. For example, if we take the state where and are garbage registers. Then, if we do not apply any further operations to those registers, according to the principle of implicit measurement, the entangled state has been measured, resulting in a collapse to either or with probability . What makes this undesirable is that wave-function collapse occurs before the program terminates, and thus may not yield the expected result.
|
https://en.wikipedia.org/wiki/Michael%20G.%20Crandall
|
Michael Grain Crandall (born November 29, 1940, in Baton Rouge, Louisiana) is an American mathematician, specializing in differential equations.
Mathematical career
In 1962 Crandall earned a baccalaureate in engineering physics from University of California, Berkeley, changed to mathematics, earning a master's in 1964 and a PhD in 1965 under Heinz Cordes at Berkeley, with a thesis that solved a problem in celestial mechanics posed by Carl Ludwig Siegel; the thesis title is Two families of plane solutions of the four body problem. In 1965 he was an instructor at Berkeley, in 1966 an assistant professor at Stanford University and from 1969 at the University of California, Los Angeles (UCLA), where he was a professor from 1973 to 1976. From 1974 to 1984 he was a professor at the Mathematics Research Center at the University of Wisconsin–Madison, from 1984 to 1990 as Hille-Professor of Mathematics. From 1988 until his retirement he was a professor at the University of California, Santa Barbara. Crandall was several times a visiting professor at the University of Paris, where he received an honorary doctorate in 1999. His legacy of contributions contains all but not limited to: Banach solutions in Euclidean spaces, Fourier transforms of planar variables, PDE concepts and iterations for sequence analysis, semigroup transform solutions, differential harmonic study of divergent hyperbole, physical transformations of finite Jacobian entities, unique harmonic populations in convergent contexts, application of abstract existence principles on non-linear contexts, normalized vector sequencing in multi-dimensional parallax geometries, and the mathematical equivalence study of topographical dissimilar nodes using traditional non-linear surfacing theories to produce distinct solutions in the realm of differential multi-variable applications.
Crandall works primarily on partial differential equations, e.g., with bifurcation theory, evolution equations, generation of semigroups
|
https://en.wikipedia.org/wiki/ARF6
|
ADP-ribosylation factor 6 (ARF6) is a member of the ADP ribosylation factor family of GTP-binding proteins. ARF6 has a variety of cellular functions that are frequently involved in trafficking of biological membranes and transmembrane protein cargo. ARF6 has specifically been implicated in endocytosis of plasma membrane proteins and also, to a lesser extent, plasma membrane protein recycling.
Function
This gene encodes a member of the human ARF gene family, which is part of the Ras superfamily. The ARF genes encode small guanine nucleotide-binding proteins that stimulate the ADP-ribosyltransferase activity of cholera toxin and play a role in vesicular trafficking and as activators of phospholipase D. The product of this gene is localized to the plasma membrane, and regulates vesicular trafficking, remodelling of membrane lipids, and signaling pathways that lead to actin remodeling. A pseudogene of this gene is located on chromosome 7.
ARF6 can interact with βarrestin upon receptor activation.
Interactions
ARF6 has been shown to interact with:
ARRB1
ARFIP2
CHRM3
EXOC5
KIAA0090
Rac1
|
https://en.wikipedia.org/wiki/List%20of%20Khmu%20plant%20common%20names
|
The following list of Khmu (Kammu Yuan dialect of Luang Namtha Province, Laos) plant names is from Svantesson et al. (2013).
Flowering plants
Other plants
Fungi
See also
List of Khmu animal common names
Wildlife of Laos
|
https://en.wikipedia.org/wiki/OpenAL
|
OpenAL (Open Audio Library) is a cross-platform audio application programming interface (API). It is designed for efficient rendering of multichannel three-dimensional positional audio. Its API style and conventions deliberately resemble those of OpenGL. OpenAL is an environmental 3D audio library, which can add realism to a game by simulating attenuation (degradation of sound over distance), the Doppler effect (change in frequency as a result of motion), and material densities.
OpenAL aimed to originally be an open standard and open-source replacement for proprietary (and generally incompatible with one another) 3D audio APIs such as DirectSound and Core Audio, though in practice has largely been implemented on various platforms as a wrapper around said proprietary APIs or as a proprietary and vendor-specific fork. While the reference implementation later became proprietary and unmaintained, there are open source implementations such as OpenAL Soft available.
History
OpenAL was originally developed in 2000 by Loki Software to help them in their business of porting Windows games to Linux. After the demise of Loki, the project was maintained for a time by the free software/open source community, and implemented on NVIDIA nForce sound cards and motherboards. It was hosted (and largely developed) by Creative Technology until circa 2012.
Since 1.1 (2009), the sample implementation by Creative has turned proprietary, with the last releases in free licenses still accessible through the project's Subversion source code repository. However, OpenAL Soft is a widely used open source alternative and remains actively maintained and extended.
While the OpenAL charter says that there will be an "Architecture Review Board" (ARB) modeled on the OpenGL ARB, no such organization has ever been formed and the OpenAL specification is generally handled and discussed via email on its public mailing list.
The original mailing list, openal-devel hosted by Creative, ran from March 2003
|
https://en.wikipedia.org/wiki/Interesting%20number%20paradox
|
The interesting number paradox is a humorous paradox which arises from the attempt to classify every natural number as either "interesting" or "uninteresting". The paradox states that every natural number is interesting. The "proof" is by contradiction: if there exists a non-empty set of uninteresting natural numbers, there would be a smallest uninteresting number – but the smallest uninteresting number is itself interesting because it is the smallest uninteresting number, thus producing a contradiction.
"Interestingness" concerning numbers is not a formal concept in normal terms, but an innate notion of "interestingness" seems to run among some number theorists. Famously, in a discussion between the mathematicians G. H. Hardy and Srinivasa Ramanujan about interesting and uninteresting numbers, Hardy remarked that the number 1729 of the taxicab he had ridden seemed "rather a dull one", and Ramanujan immediately answered that it is interesting, being the smallest number that is the sum of two cubes in two different ways.
Paradoxical nature
Attempting to classify all numbers this way leads to a paradox or an antinomy of definition. Any hypothetical partition of natural numbers into interesting and uninteresting sets seems to fail. Since the definition of interesting is usually a subjective, intuitive notion, it should be understood as a semi-humorous application of self-reference in order to obtain a paradox.
The paradox is alleviated if "interesting" is instead defined objectively: for example, the smallest natural number that does not appear in an entry of the On-Line Encyclopedia of Integer Sequences (OEIS) was originally found to be 11630 on 12 June 2009. The number fitting this definition later became 12407 from November 2009 until at least November 2011, then 13794 as of April 2012, until it appeared in sequence as of 3 November 2012. Since November 2013, that number was 14228, at least until 14 April 2014. In May 2021, the number was 20067. (This definition
|
https://en.wikipedia.org/wiki/Vapochromism
|
In chemistry, Vapochromism strongly overlaps with solvatochromism since vapochromic systems are ones in which dyes change colour in response to the vapour of an organic compound or gas. Vapochromic devices are the optical branch of electronic noses. The main applications are in sensors for detecting volatile organic compounds (VOCs) in a variety of environments, including industrial, domestic and medical areas.
An example of such a device is an array consisting of a metalloporphyrin (Lewis acid), a pH indicator dye and a solvatochromic dye. The array is scanned with a flat-bed recorder, and the result are compared with a library of known VOCs. Vaporchromic materials are sometimes Pt or Au complexes, which undergo distinct color changes when exposed to VOCs.
|
https://en.wikipedia.org/wiki/Phenice%20method
|
The Phenice method is a technique of determining the sex of a human skeleton from the innominate pelvis. In the procedure, sex is determined based on three features: the ventral arc, the subpubic concavity, and the medial aspect of the ischio-pubic ramus. As a non-metric absolute method, it relies on the recognition of discrete male and female traits. This makes the method objective, easily performable, and relatively quick (although this has been challenged by those seeking to improve the method). It is considered highly accurate, up to 96%, owing to the distinct biological differences between male and female anatomy in the pelvis, making it a highly useful method for those determining the sex of a skeleton.
Uses
Determining the sex of a human skeleton has multiple uses. Within archaeology it is essential for building a biological profile of an individual, which in turn might be used to make assumptions about sex-based roles and responsibilities or contrast life histories based on sex. It is also important for reconstructing demographics of past societies to estimate population size, family size, and other factors. Within the field of heritage it may be useful in reconstructing the appearance and life of an individual for public presentation. It also has forensic uses where it can aid in the identification of bodies for legal purposes.
History of the Method
While the pelvis has long been recognised as an important piece of skeletal morphology in determining sex, the Phenice method was proposed in 1969 by T.W. Phenice. From him it takes its name. Before Phenice’s ideas the study of the pubis focussed on aspects such as the width of the pubis, the pre-auricular suculus and the greater sciatic notch among others. Phenice considered these aspects highly relative and therefore subject to the researcher. Furthermore, they required experience to identify. Phenice’s method was originally based on the differences between the area of attachment of the crux penis or crux
|
https://en.wikipedia.org/wiki/D145E
|
D145E is a point mutation on troponin C that leads to hypertrophic cardiomyopathy disease. This mutation is caused by the change of nucleotide C to A at nucleotide 435, switching the amino acid aspartic acid to glutamic acid, which is located at the C-terminal tail. Patients with this mutation have different structure on the thin filament and alter the binding of Ca2+ at the troponin C site IV. Further, D145E causes increase in development of force and activation of ATPase in the presence of Ca2+.
|
https://en.wikipedia.org/wiki/Butanediol%20fermentation
|
2,3-Butanediol fermentation is anaerobic fermentation of glucose with 2,3-butanediol as one of the end products. The overall stoichiometry of the reaction is
2 pyruvate + NADH --> 2CO2 + 2,3-butanediol.
Butanediol fermentation is typical for the facultative anaerobes Klebsiella and Enterobacter and is tested for using the Voges–Proskauer (VP) test. There are other alternative strains that can be used, talked about in details in the Alternative Bacteria Strains section below.
The metabolic function of 2,3-butanediol is not known, although some have speculated that it was an evolutionary advantage for these microorganisms to produce a neutral product that's less inhibitory than other partial oxidation products and doesn't reduce the pH as much as mixed acids.
There are many important industrial applications that butanediol can be used for, including antifreeze, food additives, antiseptic, and pharmaceuticals. It also is produced naturally in various places of the environment.
Comparison with mixed acid fermentation
2,3-butanediol fermentation produces smaller amounts of acid than mixed acid fermentation, and butanediol, ethanol, CO2 and H2 are the end products. While equal amounts of CO2 and H2 are created during mixed acid fermentation, butanediol fermentation produces more than twice the amount of CO2 because the gases are not produced only by formate hydrogen lyase like they are in the mixed acid fermentation
2,3 Butanediol is produced at varying levels in aerated fermentations as long as the dissolved oxygen level is limiting (i.e., the culture is trying to consume more oxygen than is available). The degree of oxygen limitation dictates the ratios of 2,3-butanediol to by-products produced
Industrial applications
2,3-butanediol has a variety of industrial applications and products it can produce. The levo isomer of butanediol has a low freezing point of -60 °C, which allows it to work as an antifreeze agent. Through catalytic dehydrogenation, butanediol can
|
https://en.wikipedia.org/wiki/Tyrosine%20hydroxylase%20deficiency
|
Tyrosine hydroxylase deficiency (THD) is a disorder caused by disfunction of tyrosine hydroxylase, an enzyme involved in the biosynthesis of dopamine. This condition is one of the causes of dopa-responsive dystonia.
Symptoms
Patients present with symptoms reflecting the decreased production of dopamine: hypokinetic-rigid syndrome, dystonia, complex encephalopathy. Symptom severity and age at onset are highly variable. A review published on GeneReviews and last updated in 2017 suggests the approximate subdivision of patients into three groups based on differences in severity of symptoms, nature of symptoms, and age at onset. A review published more recently, in 2021, suggests that the disease may have a more gradual and overlapping spectrum, and categorization may be imprecise.
According to the classification on GeneReviews, three approximate phenotypes could be discerned:
1. TH-deficient dopa-responsive dystonia - the mildest phenotype with onset between 1 and 12 years of age, with its initial symptoms being lower-limb dystonia and/or difficulty in walking. Symptoms may gradually worsen over the day and become less pronounced after a period of rest.
2. TH-deficient infantile parkinsonism with motor delay - the intermediate phenotype, with onset between 3 and 12 months of age. Development of motor skills is visibly delayed, and trunkal hypotonia and parkinsonism are present.
3. TH-deficient progressive infantile encephalopathy - the most severe phenotype, with onset recognisable at the fetal stage of development. There is pronounced delay of motor development, truncal hypotonia, marked hypokinesia, limb hypertonia, hyperreflexia, oculogyric crises, ptosis, intellectual disability, and paroxysmal periods of lethargy (with increased sweating and drooling) alternating with irritability.
Diagnosis
In order to diagnose tyrosine hydroxylase deficiency, a sample of the patient's cerebrospinal fluid may be obtained to assess neurotransmitter metabolites that may be
|
https://en.wikipedia.org/wiki/Outline%20of%20software
|
The following outline is provided as an overview of and topical guide to software:
Software – collection of computer programs and related data that provides the information for the functioning of a computer. It is held in various forms of memory of the computer. It comprises procedures, algorithms, and documentation concerned with the operation of a data processing system. The term was coined to contrast to the term hardware, meaning physical devices. In contrast to hardware, software "cannot be touched". Software is also sometimes used in a more narrow sense, meaning application software only. Sometimes the term includes data that has not traditionally been associated with computers, such as film, tapes, and records.
Types
Application software – end-user applications of computers such as word processors or video games, and ERP software for groups of users.
Business software
Computer-aided design
Databases
Decision-making software
Educational software
Emotion-sensitive software
Image editing
Industrial automation
Mathematical software
Medical software
Molecular modeling software
Quantum chemistry and solid state physics software
Simulation software
Spreadsheets
Telecommunications (i.e., the Internet and everything that flows on it)
Video editing software
Video games
Word processors
Middleware controls and co-ordinates distributed systems.
Programming languages – define the syntax and semantics of computer programs. For example, many mature banking applications were written in the language COBOL, invented in 1959. Newer applications are often written in more modern languages.
System software – provides the basic functions for computer usage and helps run the computer hardware and system. It includes a combination of the following:
Device driver
Operating system
Package management system
Server
Utility
Window system
Teachware – any special breed of software or other means of product dedicated to education purposes in software engineering
|
https://en.wikipedia.org/wiki/Frazil%20ice
|
Frazil ice is a collection of loose, randomly oriented ice crystals millimeter and sub-millimeter in size, with various shapes, e.g. elliptical disks, dendrites, needles and of an irregular nature. Frazil ice forms during the winter in open-water reaches of rivers as well as in lakes and reservoirs, where and when the water is in a turbulent state, which is, in turn, induced by the action of waves and currents. Turbulence causes the water column to become supercooled, as the heat exchange between the air and the water is such that the water temperature drops below its freezing point (in order of a few tenths of °C or less). The vertical mixing associated with that turbulence provides enough energy to overcome the crystals' buoyancy, thus keeping them from floating at the surface. Frazil ice also forms in oceans, where windy conditions, wave regimes and cold air also favor the establishment of a supercooled layer. Frazil ice can be found on the downwind side of leads, and in polynyas. In these environments, that ice can eventually accumulate at the water surface into what is referred to as grease ice.
Frazil ice is notorious for blocking water intakes as crystals accumulate and build up on the intake trash rack. Such blockages negatively impact water supply facilities, hydropower plants, nuclear power facilities, and vessels navigating in cold waters, and can lead to unexpected shut downs of the facility or even collapse of the trash rack.
Formation
When the water surface begins to lose heat rapidly, the water becomes supercooled. Turbulence, caused by strong winds or flow from a river, will mix the supercooled water throughout its entire depth. The supercooled water will already be encouraging the formation of small ice crystals (frazil ice) and the crystals get taken to the bottom of the water body. Ice generally floats, but due to frazil ice's small size relative to current speeds, it has an ineffective buoyancy and can be carried to the bottom very easily.
|
https://en.wikipedia.org/wiki/Lipid%20A%20deacylase
|
Lipid A deacylase (PagL) is an outer membrane protein with lipid A 3-O-deacylase activity. It forms an 8 stranded beta barrel structure.
|
https://en.wikipedia.org/wiki/Multimagic%20cube
|
In mathematics, a P-multimagic cube is a magic cube that remains magic even if all its numbers are replaced by their k th powers for 1 ≤ k ≤ P. cubes are called bimagic, cubes are called trimagic, and cubes tetramagic. A cube is said to be semi-perfect if the k th power cubes are perfect for 1 ≤ k < P, and the P th power cube is semiperfect. If all P of the power cubes are perfect, the cube is said to be perfect.
The first known example of a bimagic cube was given by John Hendricks in 2000; it is a semiperfect cube of order 25 and magic constant 195325. In 2003, C. Bower discovered two semi-perfect bimagic cubes of order 16, and a perfect bimagic cube of order 32.
MathWorld reports that only two trimagic cubes are known, discovered by C. Bower in 2003; a semiperfect cube of order 64 and a perfect cube of order 256. It also reports that he discovered the only two known tetramagic cubes, a semiperfect cube of order 1024, and perfect cube of order 8192.
|
https://en.wikipedia.org/wiki/Packetized%20elementary%20stream
|
Packetized Elementary Stream (PES) is a specification in the MPEG-2 Part 1 (Systems) (ISO/IEC 13818-1) and ITU-T H.222.0 that defines carrying of elementary streams (usually the output of an audio or video encoder) in packets within MPEG program streams and MPEG transport streams. The elementary stream is packetized by encapsulating sequential data bytes from the elementary stream inside PES packet headers.
A typical method of transmitting elementary stream data from a video or audio encoder is to first create PES packets from the elementary stream data and then to encapsulate these PES packets inside Transport Stream (TS) packets or Program Stream (PS) packets. The TS packets can then be multiplexed and transmitted using broadcasting techniques, such as those used in an ATSC and DVB.
Transport Streams and Program Streams are each logically constructed from PES packets. PES packets shall be used to convert between Transport Streams and Program Streams. In some cases the PES packets need not be modified when performing such conversions. PES packets may be much larger than the size of a Transport Stream packet.
PES packet header
Optional PES header
While above flags indicate that values are appended into variable length optional fields, they are not just simply written out. For example, PTS (and DTS) is expanded from 33 bits to 5 bytes (40 bits). If only PTS is present, this is done by catenating 0010b, most significant 3 bits from PTS, 1, following next 15 bits, 1, rest 15 bits and 1. If both PTS and DTS are present, first 4 bits for PTS are 0011 and first 4 bits for DTS are 0001. Other appended bytes have similar but different encoding.
|
https://en.wikipedia.org/wiki/BacMam
|
Baculovirus gene transfer into Mammalian cells, known from scientific research articles as BacMam, is the use of baculovirus to deliver genes to mammalian cells. Baculoviruses are insect cell viruses that can be modified to express proteins in mammalian cells. The unmodified baculovirus is able to enter those cells; however, its genes are not expressed unless a mammalian recognizable promoter is incorporated upstream of a gene of interest. Both unmodified baculovirus and its modified counterpart are unable to replicate in humans and are thus non-infectious.
Invented by Dr. Frederick M. Boyce, BacMam is a baculovirus-mediated gene transfer technique that has gained widespread use because of advantages when compared to other transfection methods, (for reviews see, Kost, T.A. et al,). In addition, BacMam has been found to have inherent flexibility over stable cell lines, which has contributed to its adoption as a standard gene transfer technique.
General properties
The BacMam gene delivery technology is a transient expression system, which facilitates the expression of toxic gene products. It has a broad range of transduction including many primary cell types and stem cells. The baculoviral genome has a large capacity for foreign gene insertion with up to 38 kb have been tried successfully. Simultaneous delivery of multiple genes to the same cell is feasible. There are little to no microscopically observable cytopathic effects of BacMam particles on mammalian cells. The level of gene expression can be adjusted by viral dose or chemical additions using histone deacetylase inhibitors. Transduction of cells is performed by liquid-only addition and therefore BacMam is amenable to automated methods. Viruses are stable when stored at 4°C in the dark for long periods of time.
Biosafety considerations
Baculoviruses are Risk Group 1 agents that have been widely used for over 25 years for insect cell protein production applications. Baculoviruses are produced in insect cell
|
https://en.wikipedia.org/wiki/Autowave%20reverberator
|
In the theory of autowave phenomena an autowave reverberator is an autowave vortex in a two-dimensional active medium.
A reverberator appears a result of a rupture in the front of a plane autowave. Such a rupture may occur, for example, via collision of the front with a nonexcitable obstacle. In this case, depending on the conditions, either of two phenomena may arise: a spiral wave, which rotates around the obstacle, or an autowave reverberator which rotates with its tip free.
Introduction
The reverberator was one of the first autowave solutions, researchers found, and, because of this historical context, it remains by nowadays the most studied autowave object.
Up until the late 20th century, the term "auto-wave reverberator" was used very active and widely in the scientific literature, written by soviet authors, because of active developing these investigations in USSR (for more details, see "A brief history of autowave researches" in Autowave). And, inasmuch as the soviet scientific literature was very often republished in English translation (see e.g.), the term "autowave reverberator" became known also in English-speaking countries.
The reverberator is often confused with another state of the active medium, which is similar to it, - with the spiral wave. Indeed, at a superficial glance, these two autowave solutions look almost identical. Moreover, the situation is further complicated by the fact that the spiral wave may under certain circumstances become the reverberator, and the reverberator may, on the contrary, become the spiral wave!
However, it must be remembered that many features of rotating autowaves were quite thoroughly studied as long ago as the 1970s, and already at that time some significant differences in properties of a spiral wave and a reverberator were revealed. Unfortunately, all the detailed knowledge from those years remains now scattered in different publications of the 1970-1990s, which became little-known now even for the new ge
|
https://en.wikipedia.org/wiki/Specific%20name%20%28zoology%29
|
In zoological nomenclature, the specific name (also specific epithet or species epithet) is the second part (the second name) within the scientific name of a species (a binomen). The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description. For example, the scientific name for humans is Homo sapiens, which is the species name, consisting of two names: Homo is the "generic name" (the name of the genus) and sapiens is the "specific name".
Historically, specific name referred to the combination of what are now called the generic and specific names. Carl Linnaeus, who formalized binomial nomenclature, made explicit distinctions between specific, generic, and trivial names. The generic name was that of the genus, the first in the binomial, the trivial name was the second name in the binomial, and the specific the proper term for the combination of the two. For example the binomial name of the tiger, Panthera tigris:
generic name = Panthera
trivial name = tigris
specific name = Panthera tigris
This was the proper usage from the 18th century into the late 20th century, although many authors seemed to be unaware of the distinctions between trivial and specific names and inconsistent and erroneous usage even appeared the International Code of Zoölogical Nomenclature.
The grammar of species names
Grammatically, a binomen (and a trinomen, also) must be treated as if it were a Latin phrase, no matter which language the words were originally taken from. (This gives some justification to the popular usage of the phrase "Latin name" instead of the more correct phrase "scientific name".) The specific name must adhere to certain conventions of Latin grammar. The specific name can be formed as:
A noun in apposition to the genus name, for example, the scientific name of the lion, Panthera leo. In these cases, the word for the genus a
|
https://en.wikipedia.org/wiki/Sporocarp%20%28fungus%29
|
The sporocarp (also known as fruiting body, fruit body or fruitbody) of fungi is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne. The fruitbody is part of the sexual phase of a fungal life cycle, while the rest of the life cycle is characterized by vegetative mycelial growth and asexual spore production.
The sporocarp of a basidiomycete is known as a basidiocarp or basidiome, while the fruitbody of an ascomycete is known as an ascocarp. Many shapes and morphologies are found in both basidiocarps and ascocarps; these features play an important role in the identification and taxonomy of fungi.
Fruitbodies are termed epigeous if they grow on the ground, while those that grow underground are hypogeous. Epigeous sporocarps that are visible to the naked eye, especially fruitbodies of a more or less agaricoid morphology, are often called mushrooms. Epigeous sporocarps have mycelia that extend underground far beyond the mother sporocarp. There is a wider distribution of mycelia underground than sporocarps above ground. Hypogeous fungi are usually called truffles or false truffles. There is evidence that hypogeous fungi evolved from epigeous fungi. During their evolution, truffles lost the ability to disperse their spores by air currents, and propagate instead by animal consumption and subsequent defecation.
In amateur mushroom hunting, and to a large degree in academic mycology as well, identification of higher fungi is based on the features of the sporocarp.
The largest known fruitbody is a specimen of Phellinus ellipsoideus (formerly Fomitiporia ellipsoidea) found on Hainan Island, part of China. It measures up to in length and is estimated to weigh between .
Ecology
A wide variety of animals feed on epigeous and hypogeous fungi. The mammals that feed on fungi are as diverse as fungi themselves and are called mycophages. Squirrels and chipmunks eat the greatest variety of fungi, but there are many other mammals that
|
https://en.wikipedia.org/wiki/Mathematical%20descriptions%20of%20the%20electromagnetic%20field
|
There are various mathematical descriptions of the electromagnetic field that are used in the study of electromagnetism, one of the four fundamental interactions of nature. In this article, several approaches are discussed, although the equations are in terms of electric and magnetic fields, potentials, and charges with currents, generally speaking.
Vector field approach
The most common description of the electromagnetic field uses two three-dimensional vector fields called the electric field and the magnetic field. These vector fields each have a value defined at every point of space and time and are thus often regarded as functions of the space and time coordinates. As such, they are often written as (electric field) and (magnetic field).
If only the electric field (E) is non-zero, and is constant in time, the field is said to be an electrostatic field. Similarly, if only the magnetic field (B) is non-zero and is constant in time, the field is said to be a magnetostatic field. However, if either the electric or magnetic field has a time-dependence, then both fields must be considered together as a coupled electromagnetic field using Maxwell's equations.
Maxwell's equations in the vector field approach
The behaviour of electric and magnetic fields, whether in cases of electrostatics, magnetostatics, or electrodynamics (electromagnetic fields), is governed by Maxwell-Heaviside's equations:
{| class="toccolours collapsible" width="400px" style="background-color:#ECFCF4; padding:6; cellpadding=6;text-align:left;border:2px solid #50C878"
|-
|text-align="center" colspan="2"|Maxwell's equations (vector fields)
|-
| || Gauss's law
|-
| || Gauss's law for magnetism
|-
| || Faraday's law
|-
| || Ampère–Maxwell law
|}
where ρ is the charge density, which can (and often does) depend on time and position, ε0 is the electric constant, μ0 is the magnetic constant, and J is the current per unit area, also a function of time and position. The equations
|
https://en.wikipedia.org/wiki/Jacobian%20conjecture
|
In mathematics, the Jacobian conjecture is a famous unsolved problem concerning polynomials in several variables. It states that if a polynomial function from an n-dimensional space to itself has Jacobian determinant which is a non-zero constant, then the function has a polynomial inverse. It was first conjectured in 1939 by Ott-Heinrich Keller, and widely publicized by Shreeram Abhyankar, as an example of a difficult question in algebraic geometry that can be understood using little beyond a knowledge of calculus.
The Jacobian conjecture is notorious for the large number of attempted proofs that turned out to contain subtle errors. As of 2018, there are no plausible claims to have proved it. Even the two-variable case has resisted all efforts. There are currently no known compelling reasons for believing the conjecture to be true, and according to van den Essen there are some suspicions that the conjecture is in fact false for large numbers of variables (indeed, there is equally also no compelling evidence to support these suspicions). The Jacobian conjecture is number 16 in Stephen Smale's 1998 list of Mathematical Problems for the Next Century.
The Jacobian determinant
Let N > 1 be a fixed integer and consider polynomials f1, ..., fN in variables X1, ..., XN with coefficients in a field k. Then we define a vector-valued function F: kN → kN by setting:
F(X1, ..., XN) = (f1(X1, ...,XN),..., fN(X1,...,XN)).
Any map F: kN → kN arising in this way is called a polynomial mapping.
The Jacobian determinant of F, denoted by JF, is defined as the determinant of the N × N Jacobian matrix consisting of the partial derivatives of fi with respect to Xj:
then JF is itself a polynomial function of the N variables X1, ..., XN.
Formulation of the conjecture
It follows from the multivariable chain rule that if F has a polynomial inverse function G: kN → kN, then JF has a polynomial reciprocal, so is a nonzero constant. The Jacobian conjecture is the following partial con
|
https://en.wikipedia.org/wiki/ISO%201
|
ISO 1 is an international standard set by the International Organization for Standardization that specifies the standard reference temperature for geometrical product specification and verification. The temperature is fixed at 20 °C, which is equal to 293.15 kelvin and 68 degrees Fahrenheit.
Due to thermal expansion, precision length measurements need to be made at (or converted to) a defined temperature. ISO 1 helps in comparing measurements by defining such a reference temperature. The reference temperature of 20 °C was adopted by the CIPM on 15 April 1931, and became ISO recommendation number 1 in 1951. It soon replaced worldwide other reference temperatures for length measurements that manufacturers of precision equipment had used before, including 0 °C, 62 °F, and 25 °C. Among the reasons for choosing 20 °C was that this was a comfortable and practical workshop temperature and that it resulted in an integer value on both the Celsius and Fahrenheit scales.
It was the first ISO standard, issued originally as ISO/R 1, a ISO Recommendation.
See also
Metre
International Organization for Standardization
|
https://en.wikipedia.org/wiki/German%20Society%20for%20Stem%20Cell%20Research
|
The German Society for Stem Cell Research (Deutsche Gesellschaft für Stammzellforschung or GSZ), established in 2003 by Juergen Hescheler, brings scientists from around Germany together and has an emphasis on basic research in stem cell biology. The main purpose of the society is to promote stem cell research. In order to achieve this goal the society promotes the stem cell research in basic research and in academic teaching by allocating available funds to support training programs, to organize seminars and conferences, as well as instigating the exchange of students and scientists on national and international level for collaborative projects and resulting publications. The German Society for Stem Cell Research aims at establishing a network of scientists in stem cell research nationwide and eventually offering a platform to provide competent and independent counsel for all questions related to stem cell research.
History
In 2003 scientists from around Germany initiated the establishment of the German Society for Stem Cell Research with emphasis on basic research in stem cell biology. The society is a non-profit organisation, financially and politically autonomous, and is registered with the district court Cologne under the number VR 14639 since November 4, 2004. Juergen Hescheler is the chairman of the organisation.
Objectives
The main purpose of the society is to promote stem cell research. In order to achieve this goal the society will promote the stem cell research in basic research and in academic teaching by allocating available funds to support training programs, to organize seminars and conferences, as well as instigating the exchange of students and scientists on the national and international level for collaborative projects and resulting publications.
The German Society for Stem Cell Research aims at establishing a network of scientists in stem cell research nationwide, and eventually bringing them under a single platform and making a competent and
|
https://en.wikipedia.org/wiki/Sleeping%20positions
|
The sleeping position is the body configuration assumed by a person during or prior to sleeping. It has been shown to have health implications, particularly for babies.
Sleeping preferences
A Canadian survey found that 39% of respondents preferring the "log" position (lying on one's side with the arms down the side) and 28% preferring to sleep on their side with their legs bent.
A Travelodge survey found that 50% of heterosexual British couples prefer sleeping back-to-back, either not touching (27%) or touching (23%). Spooning was next, with the man on the outside 20% of the time vs. 8% with the woman on the outside. 10% favoured the "lovers' knot" (facing each other with legs intertwined), though all but 2% separated before going to sleep. The "Hollywood pose" of the woman with her head and arm on the man's chest was chosen by 4%.
Health issues
Sleep position in babies
In the 1958 edition of his best-selling book The Common Sense Book of Baby and Child Care, paediatrician Dr Benjamin Spock warned against placing a baby on its back, writing, "if [an infant] vomits, he's more likely to choke on the vomitus." However, later studies have shown that placing a young baby in a prone position increases the risk of sudden infant death syndrome (SIDS). A 2005 study concluded that "systematic review of preventable risk factors for SIDS from 1970 would have led to earlier recognition of the risks of sleeping on the front and might have prevented over 10,000 infant deaths in the UK and at least 50,000 in Europe, the USA, and Australasia."
Sleep position and snoring
It is recommended that people at risk of obstructive sleep apnea sleep on their side and with a 30° or higher elevation of the upper body. Snoring, which may be (but is not necessarily) an indicator of obstructive sleep apnea, may also be alleviated by sleeping on one's side.
Sleep position and heart disease
Modern scientific studies have suggested a beneficial effect of the right lateral decubitus position on
|
https://en.wikipedia.org/wiki/Andr%C3%A9%20N%C3%A9ron
|
André Néron (November 30, 1922, La Clayette, France – April 6, 1985, Paris, France) was a French mathematician at the Université de Poitiers who worked on elliptic curves and abelian varieties. He discovered the Néron minimal model of an elliptic curve or abelian variety, the Néron differential, the Néron–Severi group, the Néron–Ogg–Shafarevich criterion, the local height and Néron–Tate height of rational points on an abelian variety over a discrete valuation ring or Dedekind domain, and classified the possible fibers of an elliptic fibration.
Life and career
He was a student of Albert Châtelet, and his PhD students were Jean-Louis Colliot-Thélène and Gérard Ligozat.
He gave invited talks at the International Congress of Mathematicians in 1954 and 1966 . In 1983 the Académie des sciences awarded him the Émile Picard Medal.
He died of cancer in 1985.
Publications
|
https://en.wikipedia.org/wiki/Glur2%20RNA%20editing
|
Within the science of molecular biology and cell biology, for human genetics, the GRIA2 gene is located on chromosome 4q32-q33. The gene product is the ionotropic AMPA glutamate receptor 2 ( also known as Glur2 or GlurB). The protein belongs to a family of ligand-activated glutamate receptors that are sensitive to alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA). Glutamate receptors function as the main excitatory neurotransmitter at many synapses in the central nervous system. L-glutamate, an excitatory neurotransmitter, binds to the Gria2 resulting in a conformational change. This leads to the opening of the channel converting the chemical signal to an electrical impulse. AMPA receptors (AMPAR) are composed of four subunits, designated as GluR1 (GRIA1), GluR2 (GRIA2), GluR3 (GRIA3), and GluR4(GRIA4) which combine to form tetramers. They are usually heterotrimeric but can be homodimeric. Each AMPAR has four sites to which an agonist (such as L-glutamate) can bind, one for each subunit.[5]
RNA editing
Editing type
Gria2 pre-mRNA undergoes a type of editing called adenosine-to-inosine (A-to-I) editing. Adenosine deaminases acting on RNA (ADARs) are the RNA editing enzymes responsible for A-to-I editing. ADARs deaminate adenosine bases to inosine bases in a site-specific manner in double-stranded RNA substrates (dsRNA). ADAR2 has been experimentally shown to be the specifically responsible
Editing site
The pre-mRNA of GRIA2 is modified at amino acid 607, found in the second transmembrane domain of the receptor subunit. This is called the Q/R site.
Editing regulation
Editing occurs in 100% of transcripts in human brain. Editing levels are lower in other tissues. Deletion analysis determined that editing requires 5' portion of intron B. The predicted minimum fragment required for editing to occur contains inverted repeat structure separated by 120 nucleotides. The inverted repeat contains 3 double stranded elements of 22-23 base pairs with distortion aft
|
https://en.wikipedia.org/wiki/Wave%20turbulence
|
In continuum mechanics, wave turbulence is a set of nonlinear waves deviated far from thermal equilibrium. Such a state is usually accompanied by dissipation. It is either decaying turbulence or requires an external source of energy to sustain it. Examples are waves on a fluid surface excited by winds or ships, and waves in plasma excited by electromagnetic waves etc.
Appearance
External sources by some resonant mechanism usually excite waves with frequencies and wavelengths in some narrow interval. For example, shaking a container with frequency ω excites surface waves
with frequency ω/2 (parametric resonance, discovered by Michael Faraday).
When wave amplitudes are small – which usually means that the wave is far from breaking – only those waves exist that are directly excited by an external source.
When, however, wave amplitudes are not very small (for surface waves: when the fluid surface is inclined by more than few degrees) waves with different frequencies start to interact. That leads to an excitation of waves with frequencies and wavelengths in wide intervals, not necessarily in resonance with an external source. In experiments with high shaking amplitudes one initially observes waves that are in resonance with one another. Thereafter, both longer and shorter waves appear as a result of wave interaction. The appearance of shorter waves is referred to as a direct cascade while longer waves are part of an inverse cascade of wave turbulence.
Statistical wave turbulence and discrete wave turbulence
Two generic types of wave turbulence should be distinguished: statistical wave turbulence (SWT) and discrete wave turbulence (DWT).
In SWT theory exact and quasi-resonances are omitted, which allows using some statistical assumptions and describing the wave system by kinetic equations and their stationary solutions – the approach developed by Vladimir E. Zakharov. These solutions are called Kolmogorov–Zakharov (KZ) energy spectra and have the form k−α, with k t
|
https://en.wikipedia.org/wiki/Cyclodendron
|
Cyclodendron was a genus of lycophytes dating from the Permian. Plants were vascularized with reproduction by spores.
Taxonomy and distribution
The type species, C. leslii, was originally described by Seward in 1903 under the name Bothrodendron leslii and based on specimens collected in Vereeniging, Atherstone Quarry and Port Alfred, South Africa. In 1928, Kräusel would reassign this species to his newly-erected genus Cyclodendron, to which he also assigned specimens from southwest Africa and Uganda. Later authors would recognize more fossils from other Permian Gondwanan localities to belong to this species, including Australia (Reids Dome beds), India and Oman (Gharif Formation).
In Brazil, the fossil of indefinite species of the genus Cyclodendron, was located on outcrop Morro Papaléo in the city of Mariana Pimentel. They are in the geopark Paleorrota in Rio Bonito Formation and date from Sakmarian at Permian.
In 2012, C. golondrinensis was described from specimens collected in the Permian-aged La Golondrina Formation of Santa Cruz Province, Argentina. It is named after the formation.
The species C. andreisii was described in 2014 based on a series of sequentially decorticated stems. The fossil specimens were discovered in the upper Permian Yaguarí Formation of Uruguay.
|
https://en.wikipedia.org/wiki/Soname
|
In Unix and Unix-like operating systems, a soname is a field of data in a shared object file. The soname is a string, which is used as a "logical name" describing the functionality of the object. Typically, that name is equal to the filename of the library, or to a prefix thereof, e.g. libc.so.6.
Name
The soname is often used to provide version backwards-compatibility information. For instance, if versions 1.0 through 1.9 of the shared library "libx" provide identical interfaces, they would all have the same soname, e.g. "libx.so.1". If the system only includes version 1.3 of that shared object, with filename "libx.so.1.3", the soname field of the shared object tells the system that it can be used to fill the dependency for a binary which was originally compiled using version 1.2.
If the application binary interface of a library changes in a backward-incompatible way, the soname would be "bumped" or incremented, e.g. from "libx.so.1" to "libx.so.2".
The GNU linker uses the -hname or -soname=name command-line options to specify the library name field. Internally, the linker will create a DT_SONAME field and populate it with name.
Given any shared object file, one can use the following command to get the information from within the library file using objdump:
$ objdump -p libx.so.1.3 | grep SONAME
SONAME libx.so.1
See also
Application programming interface (API)
Linux
|
https://en.wikipedia.org/wiki/Gesamtkatalog%20der%20Wiegendrucke
|
Der Gesamtkatalog der Wiegendrucke (English: The Union Catalogue of Incunabula) (abbreviated as GW or GKW) is an ongoing project of the Staatsbibliothek zu Berlin and appears in conjunction with the print edition of the union catalogue of incunabula. The Gesamtkatalog serves as a bibliography or collection of cradle prints or incunabula. The word incunabula stems from the Latin word incunabulum (place of birth or beginning). In the world of books, incunabula refer to books that were printed using metal type up to the year 1500. The work is based on the description of the individual prints, each complete description consists of the bibliographic note, the collation, the description in the narrower sense, the source, and the copy. The database contains all together 36,000 descriptions of incunabula, distributed over at least 3,900 articles. The Gesamtkatalog der Wiegendrucke is available in part in print and in its entirety—in draft form—via an online database.
Publications
Volumes 1-7 of the catalogue were published in Leipzig between 1925 and 1940 by Karl W. Hiersemann; they are now out of print. Volumes 1-7 also have a second edition, which was printed in 1968; these volumes are reprinted without any changes to the content, however, they do include some improvements due to the additions in printing present at the time of reproduction. The further publication of the GW from volume 8 onwards has been resumed by the German State Library in Berlin since 1972; after a break of more than 30 years and there are now 11 volumes.
See also
Incunabula Short Title Catalogue
|
https://en.wikipedia.org/wiki/Confluency
|
In cell culture biology, confluence refers to the percentage of the surface of a culture dish that is covered by adherent cells. For example, 50 percent confluence means roughly half of the surface is covered, while 100 percent confluence means the surface is completely covered by the cells, and no more room is left for the cells to grow as a monolayer. The cell number refers to, trivially, the number of cells in a given region.
Impact on research
Many cell lines exhibit differences in growth rate or gene expression depending on the degree of confluence. Cells are typically passaged before becoming fully confluent in order to maintain their proliferation phenotype. Some cell types are not limited by contact inhibition, such as immortalized cells, and may continue to divide and form layers on top of the parent cells. To achieve optimal and consistent results, experiments are usually performed using cells at a particular confluence, depending on the cell type. Extracellular export of cell free material is also dependent on the cell confluence .
Estimation
Rule of thumb
Comparing the amount of space covered by cells with unoccupied space using the naked eye can provide a rough estimate of confluency.
Hemocytometer
A hemocytometer can be used to count cells, giving the cell number.
|
https://en.wikipedia.org/wiki/Algebra%20and%20Tiling
|
Algebra and Tiling: Homomorphisms in the Service of Geometry is a mathematics textbook on the use of group theory to answer questions about tessellations and higher dimensional honeycombs, partitions of the Euclidean plane or higher-dimensional spaces into congruent tiles. It was written by Sherman K. Stein and Sándor Szabó, and published by the Mathematical Association of America as volume 25 of their Carus Mathematical Monographs series in 1994. It won the 1998 Beckenbach Book Prize, and was reprinted in paperback in 2008.
Topics
The seven chapters of the book are largely self-contained, and consider different problems combining tessellations and algebra. Throughout the book, the history of the subject as well as the state of the art is discussed, and there are many illustrations.
The first chapter concerns a conjecture of Hermann Minkowski that, in any lattice tiling of a Euclidean space by unit hypercubes (a tiling in which a lattice of translational symmetries takes any hypercube to any other hypercube) some two cubes must meet face-to-face. This result was resolved positively by Hajós's theorem in group theory, but a generalization of this question to non-lattice tilings (Keller's conjecture) was disproved shortly before the publication of the book, in part by using similar group-theoretic methods.
Following this, three chapters concern lattice tilings by polycubes. The question here is to determine, from the shape of the polycube, whether all cubes in the tiling meet face-to-face or, equivalently, whether the lattice of symmetries must be a subgroup of the integer lattice. After a chapter on the general version of this problem, two chapters consider special classes of cross and "semicross"-shaped polycubes, both with regard to tiling and then, when these shapes do not tile, with regard to how densely they can be packed. In three dimensions, this is the notorious tripod packing problem.
Chapter five considers Monsky's theorem on the impossibility of parti
|
https://en.wikipedia.org/wiki/Pickaroon
|
A pickaroon (or picaroon) is a wood-handled (may be other materials also), metal-topped log handling tool that originates from the Alpine Region where it is called "Sappie, Zapin, Sapine". It is distinguished from a pike pole by having a shorter handle, no metal point, and an opposite curve to its hook (toward the handle rather than away); and from both a cant hook and peavey by having a fixed hook facing its handle rather than a pivoting one facing away.
A pickaroon with a down-turned point on its hook is known as a sappie or hookaroon; one with an axe blade opposite its hook an axaroon, eliminating the need to carry two tools to manage logs.
See also
Picaroons Traditional Ales – A New Brunswick brewer named after the common logging tool.
|
https://en.wikipedia.org/wiki/Generalized%20Clifford%20algebra
|
In mathematics, a Generalized Clifford algebra (GCA) is a unital associative algebra that generalizes the Clifford algebra, and goes back to the work of Hermann Weyl, who utilized and formalized these clock-and-shift operators introduced by J. J. Sylvester (1882), and organized by Cartan (1898) and Schwinger.
Clock and shift matrices find routine applications in numerous areas of mathematical physics, providing the cornerstone of quantum mechanical dynamics in finite-dimensional vector spaces. The concept of a spinor can further be linked to these algebras.
The term Generalized Clifford Algebras can also refer to associative algebras that are constructed using forms of higher degree instead of quadratic forms.
Definition and properties
Abstract definition
The -dimensional generalized Clifford algebra is defined as an associative algebra over a field , generated by
and
.
Moreover, in any irreducible matrix representation, relevant for physical applications, it is required that
, and gcd. The field is usually taken to be the complex numbers C.
More specific definition
In the more common cases of GCA, the -dimensional generalized Clifford algebra of order has the property , for all j,k, and . It follows that
and
for all j,k,l = 1,...,n, and
is the th root of 1.
There exist several definitions of a Generalized Clifford Algebra in the literature.
Clifford algebra
In the (orthogonal) Clifford algebra, the elements follow an anticommutation rule, with .
Matrix representation
The Clock and Shift matrices can be represented by matrices in Schwinger's canonical notation as
.
Notably, , (the Weyl braiding relations), and (the discrete Fourier transform).
With , one has three basis elements which, together with , fulfil the above conditions of the Generalized Clifford Algebra (GCA).
These matrices, and , normally referred to as "shift and clock matrices", were introduced by J. J. Sylvester in the 1880s. (Note that the matrices
|
https://en.wikipedia.org/wiki/Dorsal%20carpal%20branch%20of%20the%20radial%20artery
|
The dorsal carpal branch of the radial artery (posterior radial carpal artery) is a small vessel which arises beneath the extensor tendons of the thumb; crossing the carpus transversely toward the medial border of the hand, it anastomoses with the dorsal carpal branch of the ulnar artery.
The dorsal branch of the radial artery also branches into the dorsalis pollicis artery; more distally it branches into the princeps pollicis artery, and anastomoses with perforating branches of the deep palmar arch
|
https://en.wikipedia.org/wiki/Graded%20poset
|
In mathematics, in the branch of combinatorics, a graded poset is a partially-ordered set (poset) P equipped with a rank function ρ from P to the set N of all natural numbers. ρ must satisfy the following two properties:
The rank function is compatible with the ordering, meaning that for all x and y in the order, if x < y then ρ(x) < ρ(y), and
The rank is consistent with the covering relation of the ordering, meaning that for all x and y, if y covers x then ρ(y) = ρ(x) + 1.
The value of the rank function for an element of the poset is called its rank. Sometimes a graded poset is called a ranked poset but that phrase has other meanings; see Ranked poset. A rank or rank level of a graded poset is the subset of all the elements of the poset that have a given rank value.
Graded posets play an important role in combinatorics and can be visualized by means of a Hasse diagram.
Examples
Some examples of graded posets (with the rank function in parentheses) are:
the natural numbers N with their usual order (rank: the number itself), or some interval [0, N] of this poset,
Nn, with the product order (sum of the components), or a subposet of it that is a product of intervals,
the positive integers, ordered by divisibility (number of prime factors, counted with multiplicity), or a subposet of it formed by the divisors of a fixed N,
the Boolean lattice of finite subsets of a set (number of elements of the subset),
the lattice of partitions of a set into finitely many parts, ordered by reverse refinement (number of parts),
the lattice of partitions of a finite set X, ordered by refinement (number of elements of X minus number of parts),
a group and a generating set, or equivalently its Cayley graph, ordered by the weak or strong Bruhat order, and ranked by word length (length of shortest reduced word).
In particular for Coxeter groups, for example permutations of a totally ordered n-element set, with either the weak or strong Bruhat order (number of adjacent inver
|
https://en.wikipedia.org/wiki/Oncogenesis%20%28journal%29
|
Oncogenesis is a peer-reviewed open access medical journal covering the molecular biology of cancer. It was established in 2012 by Douglas R. Green as a sister journal to Oncogene, of which Green was then editor-in-chief. New articles are published exclusively online by Nature Publishing Group on a weekly basis. The editor-in-chief is Jan Paul Medema (University of Amsterdam). According to the Journal Citation Reports, the journal has a 2020 impact factor of 7.485, ranking it 40th out of 242 journals in the category "Oncology".
|
https://en.wikipedia.org/wiki/Laser-powered%20phosphor%20display
|
Laser-powered phosphor display (LPD) is a large-format display technology similar to the cathode ray tube (CRT). Prysm, Inc., a video wall designer and manufacturer in Silicon Valley, California, invented and patented the LPD technology. The key components of the LPD technology are its TD2 tiles, its image processor, and its backing frame that supports LPD tile arrays. The company unveiled the LPD in January 2010.
Operation principles
LPD uses a set of movable mirrors to direct several beams of light from several ultra-violet lasers onto a screen made of a plastic-glass hybrid material coated with color phosphor stripes. The laser draws an image onto the screen by scanning line by line from top to bottom. The energy from the lasers' light activates the phosphors, which emit photons, producing an image.
The building blocks of every Prysm video wall are the Laser Phosphor Display (LPD) tiles called the TD2. Video walls are implemented using this new generation LPD TD2 tile, a virtually seamless, bezel-free building block. TD2, launched at InfoComm 2013, features increased resolution, brightness and enhanced uniformity. A variable number of TD2 tiles can be arranged in arbitrary configurations to form videowalls in various sizes and shapes.
Advantages
The main difference between the LPD and CRT technologies is that the first excites the phosphor (that emits light to produce the images) with a scanning laser beam deflected by a moving mirror, whereas the second uses an electron beam deflected by a magnetic or electrostatic field. Whereas an electron beam must be projected through a vacuum—because in a gas, liquid, or solid medium the electrons would collide with atoms of the medium and combine with them to form ions—a laser beam can pass through air, so unlike a CRT, an LPD does not require a heavy airtight vacuum envelope (typically of glass) around the space between the beam source and the phosphor screen. Also, the collisions of the laser photons with the pho
|
https://en.wikipedia.org/wiki/Robust%20optimization
|
Robust optimization is a field of mathematical optimization theory that deals with optimization problems in which a certain measure of robustness is sought against uncertainty that can be represented as deterministic variability in the value of the parameters of the problem itself and/or its solution. It is related to, but often distinguished from, probabilistic optimization methods such as chance-constrained optimization.
History
The origins of robust optimization date back to the establishment of modern decision theory in the 1950s and the use of worst case analysis and Wald's maximin model as a tool for the treatment of severe uncertainty. It became a discipline of its own in the 1970s with parallel developments in several scientific and technological fields. Over the years, it has been applied in statistics, but also in operations research, electrical engineering, control theory, finance, portfolio management logistics, manufacturing engineering, chemical engineering, medicine, and computer science. In engineering problems, these formulations often take the name of "Robust Design Optimization", RDO or "Reliability Based Design Optimization", RBDO.
Example 1
Consider the following linear programming problem
where is a given subset of .
What makes this a 'robust optimization' problem is the clause in the constraints. Its implication is that for a pair to be admissible, the constraint must be satisfied by the worst pertaining to , namely the pair that maximizes the value of for the given value of .
If the parameter space is finite (consisting of finitely many elements), then this robust optimization problem itself is a linear programming problem: for each there is a linear constraint .
If is not a finite set, then this problem is a linear semi-infinite programming problem, namely a linear programming problem with finitely many (2) decision variables and infinitely many constraints.
Classification
There are a number of classification criteri
|
https://en.wikipedia.org/wiki/Apple%20butter
|
Apple butter (Dutch: appelstroop ) is a highly concentrated form of apple sauce produced by long, slow cooking of apples with apple juice or water to a point where the sugar in the apples caramelizes, turning the apple butter a deep brown. The concentration of sugar gives apple butter a much longer shelf life as a preserve than apple sauce.
Background
The roots of apple butter lie in Limburg (Belgium and the Netherlands) and Rhineland (Germany), conceived during the Middle Ages, when the first monasteries (with large orchards) appeared. The production of the butter was a perfect way to conserve part of the fruit production of the monasteries in that region, at a time when almost every village had its own apple-butter producers. The production of apple butter was also a popular way of using apples in colonial America, well into the 19th century.
The product contains no actual dairy butter; the term butter refers only to the butter-like thick, soft consistency, and apple butter's use as a spread for breads. Sometimes seasoned with cinnamon, clove, and other spices, apple butter is usually spread on bread, used as a side dish, an ingredient in baked goods, or as a condiment. Apple butter may also be used on sandwiches to add an interesting flavor, but is not as commonly used as in historical times.
Vinegar or lemon juice is sometimes mixed in while cooking to provide a small amount of tartness to the usually sweet apple butter. The Pennsylvania Dutch often include apple butter as part of their traditional 'seven sweets and seven sours' dinner table array.
In areas of the American South, the production of apple butter is a family event, due to the large amount of labor necessary to produce apple butter in large quantities. Traditionally, apple butter was prepared in large copper kettles outside. Large paddles were used to stir the apples, and family members would take turns stirring. In Appalachian cuisine, apple butter was the only type of fruit preserve normally
|
https://en.wikipedia.org/wiki/Rosette%20sampler
|
A rosette sampler (also known as a CTD-rosette or carousel) is a device used for water sampling in deep water. Rosette samplers are used in the ocean and large inland water bodies such as the North American Great Lakes in order to investigate quality. Rosette samplers are a key piece of equipment in oceanography and have been used to collect information over many years in repeat hydrographic surveys.
Description
A rosette sampler is made of an assembly of 12 to 36 sampling bottles. Each bottle is a volume that range from a minimum value of 1.2 L to a maximum value of 30 L. All of them constitutes the rosette sampler and are clustered around a cylinder situated in the center of the assembly, where there is a sensing system called Sea-Bird or CTD, that stands for "Conductivity, Temperature and Depth", although other variables can be measured by modern CTDs (e.g. water turbidity, dissolved oxygen concentration, chlorophyll concentration and pH).
The apparatus is attached to a wire rope. A winch on board of the boat unrolls the rope during descent and rolls up it during the ascent (i.e. at the end of the samples collection). During operations in the ocean, a rosette sampler can approach the seabed at a distance from 1 to 5 m, depending on the particular sea conditions.
The opening of each sampling bottle can be automatic (by reaching a certain depth) or manual (by operator, remotely).
Applications
Water sampling is used in general for chemical analysis and ecotoxicological assessment.
A rosette sampler is preferred to Winchester sampler for collection of water sampling at depths greater than 50 m.
|
https://en.wikipedia.org/wiki/Supratrochlear%20nerve
|
The supratrochlear nerve is a branch of the frontal nerve, itself a branch of the ophthalmic nerve (CN V1) from the trigeminal nerve (CN V). It provides sensory innervation to the skin of the forehead and the upper eyelid.
Structure
Origin
The supratrochlear nerve is the smaller of the two terminal branches of the frontal nerve (the other being the supraorbital nerve). It arises midway between the base and apex of the orbit where the frontal nerve splits into said terminal branches.
Course
The supratrochlear nerve passes medially above the trochlea of the superior oblique muscle. It then travels anteriorly above the levator palpebrae superioris muscle. It exits the orbit through the supraorbital notch or foramen. It then ascends onto the forehead beneath the corrugator supercilii muscle and frontalis muscle. It finally divides into sensory branches.
The supratrochlear nerve travels with the supratrochlear artery, a branch of the ophthalmic artery.
Branches
Before exiting the orbit, the supratrochlear nerve emits a descending branch to the infratrochlear nerve.
Function
The supratrochlear nerve provides sensory innervation to the skin and conjunctiva of the upper eyelid, and the skin of the inferomedial forehead. It may also provide sensory innervation to part of the periosteum of the frontal bone.
Clinical significance
The supratrochlear nerve may be anaesthetised for surgery of parts of the scalp. This can be used for small lesions of the scalp. It can also be used for more extensive injury to the scalp. It is often anaesthetised alongside the supraorbital artery.
Etymology
The supratrochlear nerve is named for its passage above the trochlea of the superior oblique muscle.
Additional images
|
https://en.wikipedia.org/wiki/Saul%20Perlmutter
|
Saul Perlmutter (born September 22, 1959) is a U.S. astrophysicist, a professor of physics at the University of California, Berkeley, where he holds the Franklin W. and Karen Weber Dabby Chair, and head of the International Supernova Cosmology Project at the Lawrence Berkeley National Laboratory. He is a member of both the American Academy of Arts & Sciences and the American Philosophical Society, and was elected a Fellow of the American Association for the Advancement of Science in 2003. He is also a member of the National Academy of Sciences. Perlmutter shared the 2006 Shaw Prize in Astronomy, the 2011 Nobel Prize in Physics, and the 2015 Breakthrough Prize in Fundamental Physics with Brian P. Schmidt and Adam Riess for providing evidence that the expansion of the universe is accelerating. Since 2021, he has been a member of the President’s Council of Advisors on Science and Technology (PCAST).
Education
Saul Perlmutter was born one of three children in the Ashkenazi Jewish family of Daniel D. Perlmutter, professor emeritus of chemical and biomolecular engineering at University of Pennsylvania, and Felice (Feige) D. Perlmutter (née Davidson), professor emerita of Temple University’s School of Social Administration. His maternal grandfather, the Yiddish teacher Samuel Davidson (1903–1989), emigrated to Canada (and then with his wife Chaika Newman to New York) from the Bessarabian town of Floreşti in 1919.
Perlmutter spent his childhood in the Mount Airy neighborhood of Philadelphia. He went to school in nearby Germantown; first Greene Street Friends School for the elementary grades, followed by Germantown Friends School for grades 7 through 12. He graduated with an AB in physics from Harvard magna cum laude in 1981 and received his PhD in physics from Berkeley in 1986. Perlmutter's PhD thesis, titled "An Astrometric Search for a Stellar Companion to the Sun" and supervised by Richard A. Muller, described the development and use of an automated telescope to sea
|
https://en.wikipedia.org/wiki/History%20of%20the%20floppy%20disk
|
A floppy disk is a disk storage medium composed of a disk of thin and flexible magnetic storage medium encased in a rectangular plastic carrier. It is read and written using a floppy disk drive (FDD). Floppy disks were an almost universal data format from the 1970s into the 1990s, used for primary data storage as well as for backup and data transfers between computers.
In 1967, at an IBM facility in San Jose, California, work began on a drive that led to the world's first floppy disk and disk drive. It was introduced into the market in an format in 1971. The more conveniently sized 5¼-inch disks were introduced in 1976, and became almost universal on dedicated word processing systems and personal computers. This format was more slowly replaced by the 3½-inch format, first introduced in 1982. There was a significant period where both were popular. A number of other variant sizes were introduced over time, with limited market success.
Floppy disks remained a popular medium for nearly 40 years, but their use was declining by the mid- to late 1990s. The introduction of high speed computer networking and formats based on the new NAND flash technique (like USB flash drives and memory cards) led to the eventual disappearance of the floppy disk as a standard feature of microcomputers, with a notable point in this conversion being the introduction of the floppy-less iMac in 1998. After 2000, floppy disks were increasingly rare and used primarily with older hardware and especially with legacy industrial computer equipment.
The 8-inch disk
IBM's decision in the late 1960s to use semiconductor memory as the writeable control store for future systems and control units created a requirement for an inexpensive and reliable read only device and associated medium to store and ship the control store's microprogram and at system power on to load the microprogram into the control store. The objective was a read only device costing less than $200 and medium costing less than $5.
|
https://en.wikipedia.org/wiki/CA-duality
|
In quantum gravity and quantum complexity theory, the complexity equals action duality (CA-duality) is the conjecture that the gravitational action of any semiclassical state with an asymptotically anti-de Sitter background corresponds to quantum computational complexity, and that black holes produce complexity at the fastest possible rate. In technical terms, the complexity of a quantum state on a spacelike slice of the conformal field theory dual is proportional to the action of the Wheeler–DeWitt patch (WDW patch) of that spacelike slice in the bulk. The WDW patch is the union of all possible spacelike slices of the bulk with the CFT slice as its boundary.
This conjecture has been tested against several anti-de Sitter black hole backgrounds with and without shock waves, and was found to pass all the tests. The action for the WDW patch of a wormhole grows linearly in time for an exponentially long period. Dually, quantum circuit complexity has also been shown to grow linearly for an exponentially long time
|
https://en.wikipedia.org/wiki/Content%20strategy
|
Content strategy is the planning, development, and management of content—written or in other media. The term has been particularly common in web development since the late 1990s. It is a recognized field in user experience design, and it also draws from adjacent disciplines such as information architecture, content management, business analysis, digital marketing, and technical communication.
Definitions
Content strategy has been described as planning for "the creation, publication, and governance of useful, usable content." It has also been called "a repeatable system that defines the entire editorial content development process for a website development project."
In a 2007 article titled "Content Strategy: The Philosophy of Data," Rachel Lovinger describes the goal of content strategy as using "words and data to create unambiguous content that supports meaningful, interactive experiences." Here, she also provided the analogy that "content strategy is to copywriting as information architecture is to design."
The Content Strategy Alliance combines Kevin Nichols' definition with Kristina Halvorson's and defines content strategy as "getting the right content to the right user at the right time through strategic planning of content creation, delivery, and governance."
Practitioners
Content strategists are often familiar with a wide range of approaches, techniques, and tools. The perspectives that content strategists bring also depend heavily on their professional training and education. For instance, some specialize in "front-end strategy," which includes developing personas, journey mapping the user experience, aligning business strategy and user needs, developing a brand strategy, exploring different channels, and creating style guidelines and search engine optimization guidelines. Others specialize in "back-end strategy," which includes creating content models, planning taxonomies and metadata, structuring content management systems, and building systems to su
|
https://en.wikipedia.org/wiki/Szilassi%20polyhedron
|
In geometry, the Szilassi polyhedron is a nonconvex polyhedron, topologically a torus, with seven hexagonal faces.
Coloring and symmetry
The 14 vertices and 21 edges of the Szilassi polyhedron form an embedding of the Heawood graph onto the surface of a torus.
Each face of this polyhedron shares an edge with each other face. As a result, it requires seven colours to colour all adjacent faces. This example shows that, on surfaces topologically equivalent to a torus, some subdivisions require seven colors, providing the lower bound for the seven colour theorem. The other half of the theorem states that all toroidal subdivisions can be colored with seven or fewer colors.
The Szilassi polyhedron has an axis of 180-degree symmetry. This symmetry swaps three pairs of congruent faces, leaving one unpaired hexagon that has the same rotational symmetry as the polyhedron.
Complete face adjacency
The tetrahedron and the Szilassi polyhedron are the only two known polyhedra in which each face shares an edge with each other face.
If a polyhedron with f faces is embedded onto a surface with h holes, in such a way that each face shares an edge with each other face, it follows by some manipulation of the Euler characteristic that
This equation is satisfied for the tetrahedron with h = 0 and f = 4, and for the Szilassi polyhedron with h = 1 and f = 7.
The next possible solution, h = 6 and f = 12, would correspond to a polyhedron with 44 vertices and 66 edges. However, it is not known whether such a polyhedron can be realized geometrically without self-crossings (rather than as an abstract polytope). More generally this equation can be satisfied precisely when f is congruent to 0, 3, 4, or 7 modulo 12.
History
The Szilassi polyhedron is named after Hungarian mathematician Lajos Szilassi, who discovered it in 1977. The dual to the Szilassi polyhedron, the Császár polyhedron, was discovered earlier by ; it has seven vertices, 21 edges connecting every pair of vertices, and
|
https://en.wikipedia.org/wiki/Randomized%20response
|
Randomised response is a research method used in structured survey interview. It was first proposed by S. L. Warner in 1965 and later modified by B. G. Greenberg and coauthors in 1969. It allows respondents to respond to sensitive issues (such as criminal behavior or sexuality) while maintaining confidentiality. Chance decides, unknown to the interviewer, whether the question is to be answered truthfully, or "yes", regardless of the truth.
For example, social scientists have used it to ask people whether they use drugs, whether they have illegally installed telephones, or whether they have evaded paying taxes. Before abortions were legal, social scientists used the method to ask women whether they had had abortions.
The concept is somewhat similar to plausible deniability. Plausible deniability allows the subject to credibly say that they did not make a statement, while the randomized response technique allows the subject to credibly say that they had not been truthful when making a statement.
Example
With a coin
A person is asked if they had sex with a prostitute this month. Before they answer, they flip a coin. They are then instructed to answer "yes" if the coin comes up tails, and truthfully, if it comes up heads. Only they know whether their answer reflects the toss of the coin or their true experience. It is very important to assume that people who get heads will answer truthfully, otherwise the surveyor is not able to speculate.
Half the people—or half the questionnaire population—get tails and the other half get heads when they flip the coin. Therefore, half of those people will answer "yes" regardless of whether they have done it. The other half will answer truthfully according to their experience. So whatever proportion of the group said "no", the true number who did not have sex with a prostitute is double that, based on the assumption that the two halves are probably close to the same as it is a large randomized sampling. For example, if 20% of
|
https://en.wikipedia.org/wiki/Delta%20potential
|
In quantum mechanics the delta potential is a potential well mathematically described by the Dirac delta function - a generalized function. Qualitatively, it corresponds to a potential which is zero everywhere, except at a single point, where it takes an infinite value. This can be used to simulate situations where a particle is free to move in two regions of space with a barrier between the two regions. For example, an electron can move almost freely in a conducting material, but if two conducting surfaces are put close together, the interface between them acts as a barrier for the electron that can be approximated by a delta potential.
The delta potential well is a limiting case of the finite potential well, which is obtained if one maintains the product of the width of the well and the potential constant while decreasing the well's width and increasing the potential.
This article, for simplicity, only considers a one-dimensional potential well, but analysis could be expanded to more dimensions.
Single delta potential
The time-independent Schrödinger equation for the wave function of a particle in one dimension in a potential is
where is the reduced Planck constant, and is the energy of the particle.
The delta potential is the potential
where is the Dirac delta function.
It is called a delta potential well if is negative, and a delta potential barrier if is positive. The delta has been defined to occur at the origin for simplicity; a shift in the delta function's argument does not change any of the following results.
Solving the Schrödinger equation
The potential splits the space in two parts ( and ). In each of these parts the potential is zero, and the Schrödinger equation reduces to
this is a linear differential equation with constant coefficients, whose solutions are linear combinations of and , where the wave number is related to the energy by
In general, due to the presence of the delta potential in the origin, the coefficients o
|
https://en.wikipedia.org/wiki/Enrolled%20actuary
|
An enrolled actuary is an actuary enrolled by the Joint Board for the Enrollment of Actuaries under the Employee Retirement Income Security Act of 1974 (ERISA). Enrolled actuaries, under regulations of the Department of the Treasury and the Department of Labor, perform a variety of tasks with respect to pension plans in the United States under ERISA. As of July, 2020, there were approximately 3,500 enrolled actuaries.
Qualifications
The Joint Board for the Enrollment of Actuaries administers two examinations to prospective enrolled actuaries. Once the two examinations have been passed, and an individual has also obtained sufficient relevant professional experience, that individual becomes an enrolled actuary.
The first exam (EA-1) tests basic knowledge of the mathematics of compound interest, the mathematics of life contingencies, and practical demographic analysis.
The second (EA-2) examination consists of two segments, which are offered during separate exam sittings in either the fall or the spring. Segment F covers the selection of actuarial assumptions, actuarial cost methods, and the calculation of minimum (required) and maximum (tax-deductible) contributions to pension plans. Segment L tests knowledge of relevant federal pension laws (in particular, the provisions of ERISA) as they affect pension actuarial practice.
Employers
Enrolled actuaries generally work for human resource consulting firms, investment and insurance brokers, accounting firms, government organizations, and law firms. Some firms that employ enrolled actuaries combine two or more of these practice specialties.
Organizations
Many enrolled actuaries belong to one or more of the following organizations: the Society of Actuaries, the American Academy of Actuaries. the Conference of Consulting Actuaries or the American Society of Pension Professionals & Actuaries.
Notes and references
External links
Joint Board for the Enrollment of Actuaries
Actuary
Actuary
Employee Retirement I
|
https://en.wikipedia.org/wiki/Hugo%20Dingler
|
Hugo Albert Emil Hermann Dingler (July 7, 1881, Munich – June 29, 1954, Munich) was a German scientist and philosopher.
Life
Hugo Dingler studied mathematics, philosophy, and physics with Felix Klein, Hermann Minkowski, David Hilbert, Edmund Husserl, Woldemar Voigt, and Wilhem Roentgen at the universities of Göttingen and Munich. He graduated from the University of Munich with a thesis under Aurel Voss. Dingler earned his Ph.D. in mathematics, physics and astronomy in 1906. His doctoral advisor was Ferdinand von Lindemann. In 1910 Dingler's first attempt to earn a Habilitation failed. His second try in 1912 was successful. Dingler then taught as a Privatdozent and hold lectures on mathematics, philosophy and the history of science. He became a professor at the University of Munich in 1920. Dingler got a position as Professor ordinarius in Darmstadt in 1932.
In 1934, one year after the Nazis took power Dingler was dismissed from his teaching position for still unclear reasons. Dingler himself told several interviewers that this was because of his favorable writings concerning Jews. In fact both philo-semitic as well as anti-semitic statements by Dingler had been noted.
From 1934 to 1936 he again held a teaching position.
In 1940 Dingler joined the Nazi Party and was again given a teaching position. Of Dingler's 1944 book Aufbau der exakten Fundamentalwissenschaft only thirty copies survived wartime bombing.
Thought
Dingler's position is usually characterized as "conventionalist" by Karl Popper and others. Sometimes he is called a "radical conventionalist" (also referred to as "critical voluntarism" in the secondary literature), as by the early Rudolf Carnap. Dingler himself initially characterized it as "critical conventionalism", to contrast it with the "naïve conventionalism" of other philosophers such as Poincaré, but he himself later ceased to call his position conventionalist. Dingler agrees with the conventionalists that the fundamental assumptions of geom
|
https://en.wikipedia.org/wiki/Knights%20and%20Magick%20%28miniatures%29
|
Knights and Magick is a line of miniatures published by Heritage.
Contents
Knights and Magick is a large fantasy line in packs of one to six 22mm figures, presented both as general types for armies, and individual creatures and types of characters featured in the Knights and Magick rules.
Reception
Spalding Boldrick reviewed the Knights and Magick miniatures in The Space Gamer No. 42. Boldrick commented that "Unless you are looking for figures specifically for a Knights and Magick game, there are better figure lines available. Only those figure types not covered by other lines are really worth acquiring."
|
https://en.wikipedia.org/wiki/Rectoanal%20inhibitory%20reflex
|
The rectoanal inhibitory reflex (RAIR) (also known as the anal sampling mechanism, anal sampling reflex, rectosphincteric reflex, or anorectal sampling reflex) is a reflex characterized by a transient involuntary relaxation of the internal anal sphincter in response to distention of the rectum. The RAIR provides the upper anal canal with the ability to discriminate between flatus and fecal material.
The ability of the rectum to discriminate between gaseous, liquid and solid contents is essential to the ability to voluntarily control defecation. The RAIR allows for voluntary flatulation to occur without also eliminating solid waste, irrespective of the presence of fecal material in the anal canal.
Reflex arc
The physiological basis for the RAIR is poorly understood, but it is thought to involve a coordinated response by the internal anal sphincter to rectal distention with recovery of anal pressure from the distal to the proximal sphincter. Mediated by the autonomic nervous system, the afferent limb of this reflex depends upon an intact network of interstitial cells of Cajal in the internal anal sphincter. These cells, which are mediated at least in part by nitric oxide, provide inhibitory innervation of the internal anal sphincter.
Clinical significance
Impairment of this reflex can result in fecal incontinence. The absence of a RAIR is pathognomonic for Hirschsprung's disease.
See also
External anal sphincter
Levator ani
|
https://en.wikipedia.org/wiki/Iteratee
|
In functional programming, an iteratee is a composable abstraction for incrementally processing sequentially presented chunks of input data in a purely functional fashion. With iteratees, it is possible to lazily transform how a resource will emit data, for example, by converting each chunk of the input to uppercase as they are retrieved or by limiting the data to only the five first chunks without loading the whole input data into memory. Iteratees are also responsible for opening and closing resources, providing predictable resource management.
On each step, an iteratee is presented with one of three possible types of values: the next chunk of data, a value to indicate no data is available, or a value to indicate the iteration process has finished. It may return one of three possible types of values, to indicate to the caller what should be done next: one that means "stop" (and contains the final return value), one that means "continue" (and specifies how to continue), and one that means "signal an error". The latter types of values in effect represent the possible "states" of an iteratee. An iteratee would typically start in the "continue" state.
Iteratees are used in Haskell and Scala (in the Play Framework and in Scalaz), and are also available for F#. Various slightly different implementations of iteratees exist. For example, in the Play framework, they involve Futures so that asynchronous processing can be performed.
Because iteratees are called by other code which feeds them with data, they are an example of inversion of control. However, unlike many other examples of inversion of control such as SAX XML parsing, the iteratee retains a limited amount of control over the process. It cannot reverse back and look at previous data (unless it stores that data internally), but it can stop the process cleanly without throwing an exception (using exceptions as a means of control flow, rather than to signal an exceptional event, is often frowned upon by programmer
|
https://en.wikipedia.org/wiki/Hypertrophic%20decidual%20vasculopathy
|
In pathology, hypertrophic decidual vasculopathy, abbreviated HDV, is the histomorphologic correlate of gestational hypertension, as may be seen in intrauterine growth restriction (IUGR) and HELLP syndrome.
The name of the condition describes its appearance under the microscope; the smooth muscle of the decidual (or maternal) blood vessels is hypertrophic, i.e. the muscle part of the blood vessels feeding the placenta is larger due to cellular enlargement.
Morphologic features
The morphologic features of mild and moderate HDV include:
Perivascular inflammatory cells,
+/-Vascular thrombosis,
Smooth muscle hypertrophy, and
Endothelial hyperplasia.
Severe HDV is characterized by:
Atherosis - foamy macrophages within vascular wall, and
Fibrinoid necrosis of vessel wall (amorphous eosinophilic vessel wall).
See also
Fetal thrombotic vasculopathy
Gestational diabetes
Placenta
Pregnancy
|
https://en.wikipedia.org/wiki/Cooperative%20MIMO
|
In radio, cooperative multiple-input multiple-output (cooperative MIMO, CO-MIMO) is a technology that can effectively exploit the spatial domain of mobile fading channels to bring significant performance improvements to wireless communication systems. It is also called network MIMO, distributed MIMO, virtual MIMO, and virtual antenna arrays.
Conventional MIMO systems, known as point-to-point MIMO or collocated MIMO, require both the transmitter and receiver of a communication link to be equipped with multiple antennas. While MIMO has become an essential element of wireless communication standards, including IEEE 802.11n (Wi-Fi), IEEE 802.11ac (Wi-Fi), HSPA+ (3G), WiMAX (4G), and Long-Term Evolution (4G), many wireless devices cannot support multiple antennas due to size, cost, and/or hardware limitations. More importantly, the separation between antennas on a mobile device and even on fixed radio platforms is often insufficient to allow meaningful performance gains. Furthermore, as the number of antennas is increased, the actual MIMO performance falls farther behind the theoretical gains.
Cooperative MIMO uses distributed antennas on different radio devices to achieve close to the theoretical gains of MIMO. The basic idea of cooperative MIMO is to group multiple devices into a virtual antenna array to achieve MIMO communications. A cooperative MIMO transmission involves multiple point-to-point radio links, including links within a virtual array and possibly links between different virtual arrays.
The disadvantages of cooperative MIMO come from the increased system complexity and the large signaling overhead required for supporting device cooperation. The advantages of cooperative MIMO, on the other hand, are its capability to improve the capacity, cell edge throughput, coverage, and group mobility of a wireless network in a cost-effective manner. These advantages are achieved by using distributed antennas, which can increase the system capacity by decorrelating t
|
https://en.wikipedia.org/wiki/Sieve%20of%20Pritchard
|
In mathematics, the sieve of Pritchard is an algorithm for finding all prime numbers up to a specified bound.
Like the ancient sieve of Eratosthenes, it has a simple conceptual basis in number theory.
It is especially suited to quick hand computation for small bounds.
Whereas the sieve of Eratosthenes marks off each non-prime for each of its prime factors, the sieve of Pritchard avoids considering almost all non-prime numbers by building progressively larger wheels, which represent the pattern of numbers not divisible by any of the primes processed thus far.
It thereby achieves a better asymptotic complexity, and was the first sieve with a running time sublinear in the specified bound.
Its asymptotic running-time has not been improved on, and it deletes fewer composites than any other known sieve.
It was created in 1979 by Paul Pritchard.
Since Pritchard has created a number of other sieve algorithms for finding prime numbers, the sieve of Pritchard is sometimes singled out by being called the wheel sieve (by Pritchard himself) or the dynamic wheel sieve.
Overview
A prime number is a natural number that has no natural number divisors other than the number and itself.
To find all the prime numbers less than or equal to a given integer , a sieve algorithm examines a set of candidates in the range ,
and eliminates those that are not prime, leaving the primes at the end.
The sieve of Eratosthenes examines all of the range, first removing all multiples of the first prime , then of the next prime , and so on.
The sieve of Pritchard instead examines a subset of the range consisting of numbers that occur on successive wheels,
which represent the pattern of numbers left after each successive prime is processed by the sieve of Eratosthenes.
For the 'th wheel represents this pattern.
It is the set of numbers between and the product of the first prime numbers that are not divisible by any of these prime numbers (and is said to have an associated length ).
This is bec
|
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.