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https://en.wikipedia.org/wiki/Muscone | Muscone is a macrocyclic ketone, an organic compound that is the primary contributor to the odor of musk.
The chemical structure of muscone was first elucidated by Leopold Ružička. It is a 15-membered ring ketone with one methyl substituent in the 3-position. It is an oily liquid that is found naturally as the (−)-enantiomer, (R)-3-methylcyclopentadecanone. Muscone has been synthesized as the pure (−)-enantiomer as well as the racemate. It is very slightly soluble in water and miscible with alcohol.
Natural muscone is obtained from musk, a glandular secretion of the musk deer, which has been used in perfumery and medicine for thousands of years. Since obtaining natural musk requires killing the endangered animal, nearly all muscone used in perfumery today is synthetic. It has the characteristic smell of being "musky".
One asymmetric synthesis of (−)-muscone begins with commercially available (+)-citronellal, and forms the 15-membered ring via ring-closing metathesis:
A more recent enantioselective synthesis involves an intramolecular aldol addition/dehydration reaction of a macrocyclic diketone. Muscone is now produced synthetically for use in perfumes and for scenting consumer products.
Isotopologues of muscone have been used in a study of the mechanism of olfaction. Global replacement of all hydrogens in muscone was achieved by heating muscone with Rh/C in D2O at 150 °C. It was found that the human musk-recognizing receptor, OR5AN1, identified using a heterologous olfactory receptor expression system and robustly responding to muscone, fails to distinguish between muscone and the so-prepared isotopologue in vitro. OR5AN1 is reported to bind to muscone and related musks such as civetone through hydrogen-bond formation from tyrosine-258 along with hydrophobic interactions with surrounding aromatic residues in the receptor. |
https://en.wikipedia.org/wiki/Dragon%27s%20Breath%20%28dessert%29 | Dragon's Breath is a frozen dessert made from cereal dipped in liquid nitrogen. When placed in the eater's mouth, it produces vapors which comes out of the nose and mouth, giving the dessert its name.
Description
Dragon's Breath is made using colorful cereal balls described as having a flavor similar to Froot Loops. The cereal is dipped in liquid nitrogen and served in a cup. The eater uses a stick to skewer the balls. Once in the eater's mouth, the cold of the liquid nitrogen combines with the warmth of the mouth to release visible vapors out of the nose and mouth.
According to Glutto Digest, Dragon's Breath was originally invented and served at “minibar” by José Andrés in 2008. After Andrés stopped serving it at his LA restaurant “The Bazaar” in 2009, it spread throughout Taiwan, Korea, and the Philippines over the following years.
According to The Straits Times, Dragon's Breath first appeared in the Philippines and South Korea circa 2015, but gained popularity when Los Angeles-based chain, Chocolate Chair, added it to its menu.
Dragon's Breath is noted for the spectacle of its consumption more than its flavor, with several publications commenting on its compatibility with Instagram trends.
Safety
Liquid nitrogen is used in several foods and drinks to quickly freeze them or for the vapors it produces. Its consumption poses several dangers to humans. The extreme cold temperature can cause damage to human tissue, and the displacement of oxygen by nitrogen can cause asphyxiation.
At a shop in Singapore in 2016, a woman was burned when the dessert stuck to her gums.
In October 2017, two children at the Pensacola Interstate Fair in Florida were injured while handling or consuming Dragon's Breath. A 14-year-old suffered a burn on her thumb from contact with the frozen dessert. Another child suffered second degree burns on the roof of her mouth. Following complaints, the fair's general manager announced the vendor would not be allowed to sell Dragon's Breath at |
https://en.wikipedia.org/wiki/Active%20matter | Active matter is matter composed of large numbers of active "agents", each of which consumes energy in order to move or to exert mechanical forces. Such systems are intrinsically out of thermal equilibrium. Unlike thermal systems relaxing towards equilibrium and systems with boundary conditions imposing steady currents, active matter systems break time reversal symmetry because energy is being continually dissipated by the individual constituents. Most examples of active matter are biological in origin and span all the scales of the living, from bacteria and self-organising bio-polymers such as microtubules and actin (both of which are part of the cytoskeleton of living cells), to schools of fish and flocks of birds. However, a great deal of current experimental work is devoted to synthetic systems such as artificial self-propelled particles. Active matter is a relatively new material classification in soft matter: the most extensively studied model, the Vicsek model, dates from 1995.
Research in active matter combines analytical techniques, numerical simulations and experiments. Notable analytical approaches include hydrodynamics, kinetic theory, and non-equilibrium statistical physics. Numerical studies mainly involve self-propelled-particles models, making use of agent-based models such as molecular dynamics algorithms or lattice-gas models, as well as computational studies of hydrodynamic equations of active fluids. Experiments on biological systems extend over a wide range of scales, including animal groups (e.g., bird flocks, mammalian herds, fish schools and insect swarms), bacterial colonies, cellular tissues (e.g. epithelial tissue layers, cancer growth and embryogenesis), cytoskeleton components (e.g., in vitro motility assays, actin-myosin networks and molecular-motor driven filaments). Experiments on synthetic systems include self-propelled colloids (e.g., phoretically propelled particles), driven granular matter (e.g. vibrated monolayers), swarming r |
https://en.wikipedia.org/wiki/Erd%C5%91s%20sumset%20conjecture | In additive combinatorics, the Erdős sumset conjecture is a conjecture which states that if a subset of the natural numbers has a positive upper density then there are two infinite subsets and of such that contains the sumset . It was posed by Paul Erdős, and was proven in 2019 in a paper by Joel Moreira, Florian Richter and Donald Robertson.
See also
List of conjectures by Paul Erdős
Notes
Conjectures
Conjectures that have been proved
Paul Erdős
Combinatorics |
https://en.wikipedia.org/wiki/AmigaOS | AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early versions of AmigaOS required the Motorola 68000 series of 16-bit and 32-bit microprocessors. Later versions were developed by Haage & Partner (AmigaOS 3.5 and 3.9) and then Hyperion Entertainment (AmigaOS 4.0-4.1). A PowerPC microprocessor is required for the most recent release, AmigaOS 4.
AmigaOS is a single-user operating system based on a preemptive multitasking kernel, called Exec.
It includes an abstraction of the Amiga's hardware, a disk operating system called AmigaDOS, a windowing system API called Intuition, and a desktop environment and file manager called Workbench.
The Amiga intellectual property is fragmented between Amiga Inc., Cloanto, and Hyperion Entertainment. The copyrights for works created up to 1993 are owned by Cloanto. In 2001, Amiga Inc. contracted AmigaOS 4 development to Hyperion Entertainment, and in 2009 they granted Hyperion an exclusive, perpetual, worldwide license to AmigaOS 3.1 in order to develop and market AmigaOS 4 and subsequent versions.
On December 29, 2015, the AmigaOS 3.1 source code leaked to the web; this was confirmed by the licensee, Hyperion Entertainment.
Components
AmigaOS is a single-user operating system based on a preemptive multitasking kernel, called Exec. AmigaOS provides an abstraction of the Amiga's hardware, a disk operating system called AmigaDOS, a windowing system API called Intuition and a desktop file manager called Workbench.
A command-line interface (CLI), called AmigaShell, is also integrated into the system, though it also is entirely window-based. The CLI and Workbench components share the same privileges. Notably, AmigaOS lacks any built-in memory protection.
AmigaOS is formed from two parts, namely, a firmware component called Kickstart and a software port |
https://en.wikipedia.org/wiki/Theta%2A | Theta* is an any-angle path planning algorithm that is based on the A* search algorithm. It can find near-optimal paths with run times comparable to those of A*.
Description
For the simplest version of Theta*, the main loop is much the same as that of A*. The only difference is the function. Compared to A*, the parent of a node in Theta* does not have to be a neighbour of the node as long as there is a line-of-sight between the two nodes.
Pseudocode
Adapted from.function theta*(start, goal)
// This main loop is the same as A*
gScore(start) := 0
parent(start) := start
// Initializing open and closed sets. The open set is initialized
// with the start node and an initial cost
open := {}
open.insert(start, gScore(start) + heuristic(start))
// gScore(node) is the current shortest distance from the start node to node
// heuristic(node) is the estimated distance of node from the goal node
// there are many options for the heuristic such as Euclidean or Manhattan
closed := {}
while open is not empty
s := open.pop()
if s = goal
return reconstruct_path(s)
closed.push(s)
for each neighbor of s
// Loop through each immediate neighbor of s
if neighbor not in closed
if neighbor not in open
// Initialize values for neighbor if it is
// not already in the open list
gScore(neighbor) := infinity
parent(neighbor) := Null
update_vertex(s, neighbor)
return Null
function update_vertex(s, neighbor)
// This part of the algorithm is the main difference between A* and Theta*
if line_of_sight(parent(s), neighbor)
// If there is line-of-sight between parent(s) and neighbor
// then ignore s and use the path from parent(s) to neighbor
if gScore(parent(s)) + c(parent(s), neighbor) < gScore(neighbor)
// c( |
https://en.wikipedia.org/wiki/Diode-or%20circuit | A diode-OR circuit is used in electronics to isolate two or more voltage sources. There are two typical implementations:
When a DC supply voltage needs to be generated from one of a number of different sources, for example when terminating a parallel SCSI bus, a very simple circuit like this can be used:
In digital electronics a diode-OR circuit is used to derive a simple Boolean logic function. This kind of circuit was once very common in diode–transistor logic but has been largely replaced by CMOS in modern electronics:
Logic gates |
https://en.wikipedia.org/wiki/Seed%20dispersal | In spermatophyte plants, seed dispersal is the movement, spread or transport of seeds away from the parent plant. Plants have limited mobility and rely upon a variety of dispersal vectors to transport their seeds, including both abiotic vectors, such as the wind, and living (biotic) vectors such as birds. Seeds can be dispersed away from the parent plant individually or collectively, as well as dispersed in both space and time. The patterns of seed dispersal are determined in large part by the dispersal mechanism and this has important implications for the demographic and genetic structure of plant populations, as well as migration patterns and species interactions. There are five main modes of seed dispersal: gravity, wind, ballistic, water, and by animals. Some plants are serotinous and only disperse their seeds in response to an environmental stimulus. These modes are typically inferred based on adaptations, such as wings or fleshy fruit. However, this simplified view may ignore complexity in dispersal. Plants can disperse via modes without possessing the typical associated adaptations and plant traits may be multifunctional.
Benefits
Seed dispersal is likely to have several benefits for different plant species. Seed survival is often higher away from the parent plant. This higher survival may result from the actions of density-dependent seed and seedling predators and pathogens, which often target the high concentrations of seeds beneath adults. Competition with adult plants may also be lower when seeds are transported away from their parent.
Seed dispersal also allows plants to reach specific habitats that are favorable for survival, a hypothesis known as directed dispersal. For example, Ocotea endresiana (Lauraceae) is a tree species from Latin America which is dispersed by several species of birds, including the three-wattled bellbird. Male bellbirds perch on dead trees in order to attract mates, and often defecate seeds beneath these perches where the see |
https://en.wikipedia.org/wiki/Pierre%20Gagnaire | Pierre Gagnaire (born 9 April 1950 in Apinac, Loire) is a French chef, and the head chef and owner of the eponymous Pierre Gagnaire restaurant at 6 rue Balzac in Paris (in the 8th arrondissement). Gagnaire is an iconoclastic chef at the forefront of the fusion cuisine movement. Beginning his career in St. Etienne where he won three Michelin Stars, Gagnaire tore at the conventions of classic French cooking by introducing jarring juxtapositions of flavours, tastes, textures, and ingredients.
On his website, Gagnaire gives his mission statement as the wish to run a restaurant which is 'facing tomorrow but respectful of yesterday' ("tourné vers demain mais soucieux d'hier").
In Europe
The restaurant, Pierre Gagnaire, specializes in modern French cuisine and has garnered three Michelin stars. Gagnaire is also head chef of Sketch in London. In 2005, both restaurants were ranked in the S.Pellegrino World's 50 Best Restaurants by industry magazine Restaurant, with Pierre Gagnaire ranking third for three consecutive years (2006, 2007, and 2008).
In the United States
In December 2009, Gagnaire made his United States debut with Twist, a new restaurant at the Mandarin Oriental in Las Vegas, which has since received a Forbes Five-Star Award but has since closed.
Media appearances
Pierre Gagnaire has made appearances on Fuji TV's Iron Chef. He represented France in the 1995 Iron Chef World Cup in Tokyo, with the other chefs chosen being Italy's Gianfranco Vissani and Hong Kong's Xu Cheng as well as Iron Chef Japanese Rokusaburo Michiba representing Japan. He also appeared in the "France Battle Special" at Château de Brissac, where he battled Iron Chef French Hiroyuki Sakai.
Awards
In 2015, Gagnaire won a Best Chef in the World award.
Restaurants
Paris, Pierre Gagnaire, 1996–
Paris, Gaya rive gauche par Pierre Gagnaire, 2005–
Berlin, Les Solistes by Pierre Gagnaire, 2013–2016 (closed)
Bordeaux, La Grande Maison
Châtelaillon, Gaya Cuisine De Bords de Mer
Courchevel, Pie |
https://en.wikipedia.org/wiki/RNR3 | RNA, ribosomal 3, also known as RNR3, is a human gene. It is a minor isoform of large subunit of ribonucleotide-diphosphate reductase; the RNR complex catalyzes rate-limiting step in dNTP synthesis, regulated by DNA replication and DNA damage checkpoint pathways via localization of small subunits; RNR3 has a paralog, RNR1, that arose from the whole genome duplication. |
https://en.wikipedia.org/wiki/Congruence%20relation | In abstract algebra, a congruence relation (or simply congruence) is an equivalence relation on an algebraic structure (such as a group, ring, or vector space) that is compatible with the structure in the sense that algebraic operations done with equivalent elements will yield equivalent elements. Every congruence relation has a corresponding quotient structure, whose elements are the equivalence classes (or congruence classes) for the relation.
Basic example
The prototypical example of a congruence relation is congruence modulo on the set of integers. For a given positive integer , two integers and are called congruent modulo , written
if is divisible by (or equivalently if and have the same remainder when divided by ).
For example, and are congruent modulo ,
since is a multiple of 10, or equivalently since both and have a remainder of when divided by .
Congruence modulo (for a fixed ) is compatible with both addition and multiplication on the integers. That is,
if
and
then
and
The corresponding addition and multiplication of equivalence classes is known as modular arithmetic. From the point of view of abstract algebra, congruence modulo is a congruence relation on the ring of integers, and arithmetic modulo occurs on the corresponding quotient ring.
Definition
The definition of a congruence depends on the type of algebraic structure under consideration. Particular definitions of congruence can be made for groups, rings, vector spaces, modules, semigroups, lattices, and so forth. The common theme is that a congruence is an equivalence relation on an algebraic object that is compatible with the algebraic structure, in the sense that the operations are well-defined on the equivalence classes.
Example: Groups
For example, a group is an algebraic object consisting of a set together with a single binary operation, satisfying certain axioms. If is a group with operation , a congruence relation on is an equivalence relatio |
https://en.wikipedia.org/wiki/Polyozellus | Polyozellus is a fungal genus in the family Thelephoraceae, a grouping of mushrooms known collectively as the leathery earthfans. Previously considered a monotypic genus, it now contains the Polyozellus multiplex species complex. The genus name is derived from the Greek poly meaning many, and oz, meaning branch. It is commonly known as the blue chanterelle, the clustered blue chanterelle, or, in Alaska, the black chanterelle. The distinctive fruit body of this species comprises blue- to purple-colored clusters of vase- or spoon-shaped caps with veiny wrinkles on the undersurface that run down the length of the stem.
Polyozellus has had a varied taxonomic history and has been reclassified several times at both the family and genus level. The range of Polyozellus includes North America and eastern Asia, where it grows on the ground of coniferous forests, usually under spruce and fir trees. It contains edible species, and has been harvested for commercial purposes.
History and taxonomy
The first published description of the species was written by botanist Lucien M. Underwood in 1899, based on a specimen found the previous year in the woods of Mount Desert, Maine. Although he called the new species a Cantharellus, he noted that "the plant is a remarkable one and from its habit might well form a distinct genus since it has little in common with Cantharellus except its fold-like gills." In 1910, William Murrill transferred it to the new genus Polyozellus; Murrill thought the compound structure of the stem to be a sufficiently unique characteristic to warrant it being separated from Cantharellus species, which have simpler stem structures. In 1920, specimens from a Japanese collection compiled by A. Yasuda were sent to mycologist Curtis Gates Lloyd, who believed the fungus to be a new species and named it Phyllocarbon yasudai.
No further collections of the fungus were reported until 1937, when it was found in Quebec, Canada. The next year, Paul Shope considered the g |
https://en.wikipedia.org/wiki/Fluorescence%20intermittency | Fluorescence intermittency, or blinking, is the phenomenon of random switching between ON (bright) and OFF (dark) states of the emitter under its continuous excitation. It is a common property of the nanoscale emitters (molecular fluorophores, colloidal quantum dots) related to the competition between the radiative and non-radiative relaxation pathways.
The peculiar feature of such blinking in most cases is the power-law (in contrast to exponential) statistics of the ON and OFF time distributions, meaning that the measurements of the time-averaged intensity of a single emitter is not reproducible in different experiments and implying a complex dynamics of the involved process. In other words, in one experiment the emitter can blink frequently, while in another it may stay ON (or OFF) for almost entire length of the experiment (even for extremely long measurement times).
For CdSe-ZnS core-shell nanocrystals, "charge trapping" is the dominant theory explaining observed power-law blinking kinetics. Charge carrier trapping describes the transfer of a charge carrier from a delocalized electronic state of the nanocrystal to a localized state.
See also
Fluorescence intermittency in colloidal nanocrystals |
https://en.wikipedia.org/wiki/Spiral%20plater | A spiral plater is an instrument used to dispense a liquid sample onto a Petri dish in a spiral pattern. Commonly used as part of a CFU count procedure for the purpose of determining the number of microbes in the sample. In this setting, after spiral plating, the Petri dish is incubated for several hours after which the number of colony forming microbes (CFU) is determined. Spiral platers are also used for research, clinical diagnostics and as a method for covering a Petri dish with bacteria before placing antibiotic discs for AST.
Mode of action
The spiral plater rotates the dish while simultaneously dispensing the liquid and either linearly moving the dish or the dispensing tip. This creates the common spiral pattern. If all movements are done in constant speed, the spiral created would have a lower concentration on the outside of the plate than on the inside. More advanced spiral platers provide different options for spiral patterns such as constant concentration (by slowing down the spinning and / or the lateral movements) or exponential concentration (by speeding up the spinning and / or the lateral movements).
In food and cosmetic testing
Spiral plating is used extensively for microbiological testing of food, milk and milk products and cosmetics. It is an approved method by the FDA. The advantage of spiral plating is less plates used versus plating manually because different concentrations are present on each plate. This also makes it harder to count the colonies and requires special techniques and equipment.
Stand-alone vs. Add-on
Spiral platers are either available as stand-alone instruments that are fed manually with plates and samples or fed automatically using dedicated stackers. Alternatively spiral platers are available as integrated devices as part of larger automated platforms. In this case a larger workflow is often automated, e.g. plating, incubation and counting. |
https://en.wikipedia.org/wiki/Log%20shipping | Log shipping is the process of automating the backup of transaction log files on a primary (production) database server, and then restoring them onto a standby server. This technique is supported by Microsoft SQL Server, 4D Server, MySQL, and PostgreSQL. Similar to replication, the primary purpose of log shipping is to increase database availability by maintaining a backup server that can replace a production server quickly. Other databases such as Adaptive Server Enterprise and Oracle Database support the technique but require the Database Administrator to write code or scripts to perform the work.
Although the actual failover mechanism in log shipping is manual, this implementation is often chosen due to its low cost in human and server resources, and ease of implementation. In comparison, SQL server clusters enable automatic failover, but at the expense of much higher storage costs. Compared to database replication, log shipping does not provide as much in terms of reporting capabilities, but backs up system tables along with data tables, and locks the standby server from users' modifications. A replicated server can be modified (e.g. views) and is therefore unsuitable for failover purposes. |
https://en.wikipedia.org/wiki/Milner%E2%80%93Rado%20paradox | In set theory, a branch of mathematics, the Milner – Rado paradox, found by , states that every ordinal number less than the successor of some cardinal number can be written as the union of sets where is of order type at most κn for n a positive integer.
Proof
The proof is by transfinite induction. Let be a limit ordinal (the induction is trivial for successor ordinals), and for each , let be a partition of satisfying the requirements of the theorem.
Fix an increasing sequence cofinal in with .
Note .
Define:
Observe that:
and so .
Let be the order type of . As for the order types, clearly .
Noting that the sets form a consecutive sequence of ordinal intervals, and that each is a tail segment of , then: |
https://en.wikipedia.org/wiki/List%20of%20podcast%20clients | A podcast client, or podcatcher, is a computer program used to stream or download podcasts, usually via an RSS or XML feed.
While podcast clients are best known for streaming and downloading podcasts, many are also capable of downloading video, newsfeeds, text, and pictures. Some of these podcast clients can also automate the transfer of received audio files to a portable media player. Although many include a directory of high-profile podcasts, they generally allow users to manually subscribe directly to a feed by providing the URL.
The core concepts had been developing since 2000, the first commercial podcast client software was developed in 2001.
Podcasts were made popular when Apple added podcatching to its iTunes software and iPod portable media player in June 2005. Apple Podcasts is currently included in all Apple devices, such as iPhone, iPad and Mac computers.
Podcast clients
See also
Comparison of audio player software |
https://en.wikipedia.org/wiki/Clearfield%2C%20Inc. | Clearfield, Inc. manufactures and distributes passive connectivity products. Their fiber management and enclosure platform consolidates, distributes, and protects fiber through inside plant facilities, to outside plant facilities, to the home, and to the drop-off points in between. Clearfield's products service the wireless, cable, and telephone service providers, municipal-owned utilities, and non-traditional providers. Clearfield was founded in 2008 and is headquartered in Minneapolis, Minnesota.
History
1981–2008
Clearfield's history began in the late 1980s with the merging of Americable and Computer System Products. Moving forward under the business name Americable, in 2003 the company was purchased by APA Enterprises. In 2007, APA Enterprises changed course after several consecutive years of profit losses. In June 2007, Cheri Beranek took the new role of CEO. Under the new leadership, APA Enterprises redefined itself with a new vision by rebranding the company as Clearfield at the start of 2008.
2008–Present
Clearfield reported its first profitable quarter on September, 30th 2008. The company moved into its 60% larger Minneapolis Headquarters in January 2015.
Organization
Clearfield, Inc. manufacturers its fiber optic components out of its corporate office in Minneapolis, Minnesota and out of its satellite plant in Tijuana, Mexico.
Awards
Clearfield rated #14 in the top 25 small businesses in America in 2013
Eureka! Award for ingenuity and innovation
External links
Clearfield's Official Website |
https://en.wikipedia.org/wiki/Paola%20Loreti | Paola Loreti is an Italian mathematician, and a professor of mathematical analysis at Sapienza University of Rome.
She is known for her research on Fourier analysis, control theory, and non-integer representations. The Komornik–Loreti constant, the smallest non-integer base for which the representation of 1 is unique, is named after her and Vilmos Komornik.
Loreti earned a laurea from Sapienza University in 1984. Her dissertation, Programmazione dinamica ed equazione di Bellman [dynamic programming and the Bellman equation] was supervised by Italo Capuzzo-Dolcetta.
With Vilmos Komornik, Loreti is the author of the book Fourier Series in Control Theory (Springer, 2005). |
https://en.wikipedia.org/wiki/Miroslav%20Fiedler | Miroslav Fiedler (7 April 1926 – 20 November 2015) was a Czech mathematician known for his contributions to linear algebra, graph theory and algebraic graph theory.
His article, "Algebraic Connectivity of Graphs", published in the Czechoslovak Math Journal in 1973, established the use of the eigenvalues of the Laplacian matrix of a graph to create tools for measuring algebraic connectivity in algebraic graph theory. Fiedler is honored by the Fiedler eigenvalue (the second smallest eigenvalue of the graph Laplacian), with its associated Fiedler eigenvector, as the names for the quantities that characterize algebraic connectivity. Since Fiedler's original contribution, this structure has become essential to large areas of research in network theory, flocking, distributed control, clustering, multi-robot applications and image segmentation. |
https://en.wikipedia.org/wiki/Cray%20MTA | The Cray MTA, formerly known as the Tera MTA, is a supercomputer architecture based on thousands of independent threads, fine-grain communication and synchronization between threads, and latency tolerance for irregular computations.
Each MTA processor (CPU) has a high-performance ALU with many independent register sets, each running an independent thread. For example, the Cray MTA-2 uses 128 register sets and thus 128 threads per CPU/ALU. All MTAs to date use a barrel processor arrangement, with a thread switch on every cycle, with blocked (stalled) threads skipped to avoid wasting ALU cycles. When a thread performs a memory read, execution blocks until data returns; meanwhile, other threads continue executing. With enough threads (concurrency), there are nearly always runnable threads to "cover" for blocked threads, and the ALUs stay busy. The memory system uses full/empty bits to ensure correct ordering. For example, an array is initially written with "empty" bits, and any thread reading a value from blocks until another thread writes a value. This ensures correct ordering, but allows fine-grained interleaving and provides a simple programming model. The memory system is also "randomized", with adjacent physical addresses going to different memory banks. Thus, when two threads access memory simultaneously, they rarely conflict unless they are accessing the same location.
A goal of the MTA is that porting codes from other machines is straightforward, but gives good performance. A parallelizing FORTRAN compiler can produce high performance for some codes with little manual intervention. Where manual porting is required, the simple and fine-grained synchronization model often allows programmers to write code the "obvious" way yet achieve good performance. A further goal is that programs for the MTA will be scalable that is, when run on an MTA with twice as many CPUs, the same program will have nearly twice the performance. Both of these are challenges |
https://en.wikipedia.org/wiki/Nonextensive%20entropy | Entropy is considered to be an extensive property, i.e., that its value depends on the amount of material present. Constantino Tsallis has proposed a nonextensive entropy (Tsallis entropy), which is a generalization of the traditional Boltzmann–Gibbs entropy.
The rationale behind the theory is that Gibbs-Boltzmann entropy leads to systems that have a strong dependence on initial conditions. In reality most materials behave quite independently of initial conditions.
Nonextensive entropy leads to nonextensive statistical mechanics, whose typical functions are power laws, instead of the traditional exponentials.
See also
Tsallis entropy
Statistical mechanics
Entropy and information
Thermodynamic entropy
Information theory |
https://en.wikipedia.org/wiki/Suslin%20operation | In mathematics, the Suslin operation 𝓐 is an operation that constructs a set from a collection of sets indexed by finite sequences of positive integers.
The Suslin operation was introduced by and . In Russia it is sometimes called the A-operation after Alexandrov. It is usually denoted by the symbol 𝓐 (a calligraphic capital letter A).
Definitions
A Suslin scheme is a family of subsets of a set indexed by finite sequences of non-negative integers. The Suslin operation applied to this scheme produces the set
Alternatively, suppose we have a Suslin scheme, in other words a function from finite sequences of positive integers to sets . The result of the Suslin operation is the set
where the union is taken over all infinite sequences
If is a family of subsets of a set , then is the family of subsets of obtained by applying the Suslin operation to all collections as above where all the sets are in .
The Suslin operation on collections of subsets of has the property that . The family is closed under taking countable unions or intersections, but is not in general closed under taking complements.
If is the family of closed subsets of a topological space, then the elements of are called Suslin sets, or analytic sets if the space is a Polish space.
Example
For each finite sequence , let be the infinite sequences that extend .
This is a clopen subset of .
If is a Polish space and is a continuous function, let .
Then is a Suslin scheme consisting of closed subsets of and . |
https://en.wikipedia.org/wiki/Topological%20game | In mathematics, a topological game is an infinite game of perfect information played between two players on a topological space. Players choose objects with topological properties such as points, open sets, closed sets and open coverings. Time is generally discrete, but the plays may have transfinite lengths, and extensions to continuum time have been put forth. The conditions for a player to win can involve notions like topological closure and convergence.
It turns out that some fundamental topological constructions have a natural counterpart in topological games; examples of these are the Baire property, Baire spaces, completeness and convergence properties, separation properties, covering and base properties, continuous images, Suslin sets, and singular spaces. At the same time, some topological properties that arise naturally in topological games can be generalized beyond a game-theoretic context: by virtue of this duality, topological games have been widely used to describe new properties of topological spaces, and to put known properties under a different light. There are also close links with selection principles.
The term topological game was first introduced by Claude Berge,
who defined the basic ideas and formalism in analogy with topological groups. A different meaning for topological game, the concept of “topological properties defined by games”, was introduced in the paper of Rastislav Telgársky,
and later "spaces defined by topological games";
this approach is based on analogies with matrix games, differential games and statistical games, and defines and studies topological games within topology. After more than 35 years, the term “topological game” became widespread, and appeared in several hundreds of publications. The survey paper of Telgársky
emphasizes the origin of topological games from the Banach–Mazur game.
There are two other meanings of topological games, but these are used less frequently.
The term topological game introduced by Leon P |
https://en.wikipedia.org/wiki/Parasoft%20Virtualize | Parasoft Virtualize is a service virtualization product that can create, deploy, and manage simulated test environments for software development and software testing purposes. These environments simulate the behavior of dependent resources that are unavailable, difficult to access, or difficult to configure for development or testing. It simulates the behavior of dependent resources such as mainframes, ERP systems, databases, web services, third-party information systems, or other systems that are out of direct developer/tester control.
The product is used in conjunction with hardware/OS virtualization to provide developers and testers with the resources they need to execute their development and testing tasks earlier, faster, or more completely. Its technologies for automating continuous testing are used as part of continuous delivery, continuous integration, and continuous release.
Background
In 2002, Parasoft released technology to "create service implementation stubs which emulate critical functionality that cannot be made available for testing.". This technology was introduced in Parasoft SOAtest. Since 2002, the technology was extended with "intelligent stubs [that] emulate the behaviour of a running system, allowing the developer to test services in the context of an application's actual behaviour and not on the live running system.". In 2009, the technology was extended with "application behavior virtualization," which can "create copies of both applications and back-end systems so a developer can reference such applications or systems when developing software."
The technology was extended and released as a separate product in 2011.
Parasoft created a free community edition in 2017 that allows individual users and small projects to use service virtualization at no cost.
Industry recognition
Parasoft Virtualize was awarded the 2012 Jolt Awards Grand Prize by a panel of Dr. Dobb's Journal-appointed judges. This annual award showcases products that have " |
https://en.wikipedia.org/wiki/Mirror%20%28programming%29 | In computer programming, a mirror is a reflection mechanism that is completely decoupled from the object whose structure is being introspected. This is as opposed to traditional reflection, for example in Java, where one introspects an object using methods from the object itself (e.g. getClass()).
Mirrors adhere to the qualities of encapsulation, stratification and ontological correspondence.
Benefits
Decoupling the reflection mechanism from the objects themselves allows for a few benefits:
The object's interface is not polluted, so there is no danger of breaking reflection by overriding a reflective method.
There can be different mirror systems.
The mirror system can be removed entirely (potentially allowing for optimizations).
A mirror system can operate on remote code, since it is not coupled with a particular machine.
Languages that use mirrors
Dart, via its reflect function.
Inko, via its std::mirror module.
Rubinius (Ruby implementation), via its Rubinius::Mirror.reflect method.
Scala
Swift, via its reflect function. |
https://en.wikipedia.org/wiki/Protylopus | Protylopus is an extinct genus of camel that lived during middle to late Eocene some 50-40 million years ago in North America.
Along with being the oldest camel known, it was also the smallest, reaching a length of , and probably weighing around . Based on its teeth, it probably fed on the soft leaves of forest plants. Protylopus's front legs were shorter than the hind legs, and ended in four-toed feet. The hind legs also ended in four toes, but most of the weight was carried by the third and fourth, so it may have raised itself up on its back legs like the modern day gerenuk antelope to feed. The shape of the toes suggests that the animal possessed hooves, rather than the foot-pads of modern camels. |
https://en.wikipedia.org/wiki/Rabi%20problem | The Rabi problem concerns the response of an atom to an applied harmonic electric field, with an applied frequency very close to the atom's natural frequency. It provides a simple and generally solvable example of light–atom interactions and is named after Isidor Isaac Rabi.
Classical Rabi problem
In the classical approach, the Rabi problem can be represented by the solution to the driven damped harmonic oscillator with the electric part of the Lorentz force as the driving term:
where it has been assumed that the atom can be treated as a charged particle (of charge e) oscillating about its equilibrium position around a neutral atom. Here xa is its instantaneous magnitude of oscillation, its natural oscillation frequency, and its natural lifetime:
which has been calculated based on the dipole oscillator's energy loss from electromagnetic radiation.
To apply this to the Rabi problem, one assumes that the electric field E is oscillatory in time and constant in space:
and xa is decomposed into a part ua that is in-phase with the driving E field (corresponding to dispersion) and a part va that is out of phase (corresponding to absorption):
Here x0 is assumed to be constant, but ua and va are allowed to vary in time. However, if the system is very close to resonance (), then these values will be slowly varying in time, and we can make the assumption that , and , .
With these assumptions, the Lorentz force equations for the in-phase and out-of-phase parts can be rewritten as
where we have replaced the natural lifetime with a more general effective lifetime T (which could include other interactions such as collisions) and have dropped the subscript a in favor of the newly defined detuning , which serves equally well to distinguish atoms of different resonant frequencies. Finally, the constant
has been defined.
These equations can be solved as follows:
After all transients have died away, the steady-state solution takes the simple f |
https://en.wikipedia.org/wiki/Method%20of%20Chester%E2%80%93Friedman%E2%80%93Ursell | In asymptotic analysis, the method of Chester–Friedman–Ursell is a technique to find asymptotic expansions for contour integrals. It was developed as an extension of the steepest descent method for getting uniform asymptotic expansions in the case of coalescing saddle points. The method was published in 1957 by Clive R. Chester, Bernard Friedman and Fritz Ursell.
Method
Setting
We study integrals of the form
where is a contour and
are two analytic functions in the complex variable and continuous in .
is a large number.
Suppose we have two saddle points of with multiplicity that depend on a parameter . If now an exists, such that both saddle points coalescent to a new saddle point with multiplicity , then the steepest descent method no longer gives uniform asymptotic expansions.
Procedure
Suppose there are two simple saddle points and of and suppose that they coalescent in the point .
We start with the cubic transformation of , this means we introduce a new complex variable and write
where the coefficients and will be determined later.
We have
so the cubic transformation will be analytic and injective only if and are neither nor . Therefore and must correspond to the zeros of , i.e. with and . This gives the following system of equations
we have to solve to determine and . A theorem by Chester–Friedman–Ursell (see below) says now, that the cubic transform is analytic and injective in a local neighbourhood around the critical point .
After the transformation the integral becomes
where is the new contour for and
The function is analytic at for and also at the coalescing point for . Here ends the method and one can see the integral representation of the complex Airy function.
Chester–Friedman–Ursell note to write not as a single power series but instead as
to really get asymptotic expansions.
Theorem by Chester–Friedman–Ursell
Let and be as above. The cubic transformation
with the above derived values for and , s |
https://en.wikipedia.org/wiki/Circle%20packing%20in%20an%20isosceles%20right%20triangle | Circle packing in a right isosceles triangle is a packing problem where the objective is to pack unit circles into the smallest possible isosceles right triangle.
Minimum solutions (lengths shown are length of leg) are shown in the table below. Solutions to the equivalent problem of maximizing the minimum distance between points in an isosceles right triangle, were known to be optimal for and were extended up to .
In 2011 a heuristic algorithm found 18 improvements on previously known optima, the smallest of which was for . |
https://en.wikipedia.org/wiki/Ecological%20goods%20and%20services | Ecological goods and services (EG&S) are the economical benefits (goods and services) arising from the ecological functions of ecosystems. Such benefits accrue to all living organisms, including animals and plants, rather than to humans alone. However, there is a growing recognition of the importance to society that ecological goods and services provide for health, social, cultural, and economic needs.
Introduction
Examples of ecological goods include clean air, and abundant fresh water. Examples of ecological services include purification of air and water, maintenance of biodiversity, decomposition of wastes, soil and vegetation generation and renewal, pollination of crops and natural vegetation, groundwater recharge through wetlands, seed dispersal, greenhouse gas mitigation, and aesthetically pleasing landscapes. The products and processes of ecological goods and services are complex and occur over long periods of time. They are a sub-category of public goods.
The concern over ecological goods and services arises because we are losing them at an unsustainable rate, and therefore land use managers must devise a host of tools to encourage the provision of more ecological goods and services. Rural and suburban settings are especially important, as lands that are developed and converted from their natural state lose their ecological functions. Therefore, ecological goods and services provided by privately held lands become increasingly important.
Markets
A market may be created wherein ecological goods and services are demanded by society and supplied by public and private landowners. Some believe that public lands alone are not adequate to supply this market, and that privately held lands are needed to close this gap. What has emerged is the notion that rural landowners who provide ecological goods and services to society through good stewardship practices on their land should be duly compensated. The main tool to accomplish this to date has been to pay farmers |
https://en.wikipedia.org/wiki/Connection%20Machine | A Connection Machine (CM) is a member of a series of massively parallel supercomputers that grew out of doctoral research on alternatives to the traditional von Neumann architecture of computers by Danny Hillis at Massachusetts Institute of Technology (MIT) in the early 1980s. Starting with CM-1, the machines were intended originally for applications in artificial intelligence (AI) and symbolic processing, but later versions found greater success in the field of computational science.
Origin of idea
Danny Hillis and Sheryl Handler founded Thinking Machines Corporation (TMC) in Waltham, Massachusetts, in 1983, moving in 1984 to Cambridge, MA. At TMC, Hillis assembled a team to develop what would become the CM-1 Connection Machine, a design for a massively parallel hypercube-based arrangement of thousands of microprocessors, springing from his PhD thesis work at MIT in Electrical Engineering and Computer Science (1985). The dissertation won the ACM Distinguished Dissertation prize in 1985, and was presented as a monograph that overviewed the philosophy, architecture, and software for the first Connection Machine, including information on its data routing between central processing unit (CPU) nodes, its memory handling, and the programming language Lisp applied in the parallel machine. Very early concepts contemplated just over a million processors, each connected in a 20-dimensional hypercube, which was later scaled down.
Designs
Each CM-1 microprocessor has its own 4 kilobits of random-access memory (RAM), and the hypercube-based array of them was designed to perform the same operation on multiple data points simultaneously, i.e., to execute tasks in single instruction, multiple data (SIMD) fashion. The CM-1, depending on the configuration, has as many as 65,536 individual processors, each extremely simple, processing one bit at a time. CM-1 and its successor CM-2 take the form of a cube 1.5 meters on a side, divided equally into eight smaller cubes. Each subcub |
https://en.wikipedia.org/wiki/Countdown | A countdown is a sequence of backward counting to indicate the time remaining before an event is scheduled to occur. NASA commonly employs the terms "L-minus" and "T-minus" during the preparation for and anticipation of a rocket launch, and even "E-minus" for events that involve spacecraft that are already in space, where the "T" could stand for "Test" or "Time", and the "E" stands for "Encounter", as with a comet or some other space object.
Other events for which countdowns are commonly used include the detonation of an explosive, the start of a race, the start of the New Year, or any anxiously anticipated event. An early use of a countdown once signaled the start of a Cambridge University rowing race.
One of the first known associations with rockets was in the 1929 German science fiction movie Frau im Mond (English: Woman in the Moon) written by Thea von Harbou and directed by Fritz Lang in an attempt to increase the drama of the launch sequence of the story's lunar-bound rocket.
Rocketry
A countdown is a carefully devised set of procedures ending with the ignition of a rocket's engine. Depending on the type of vehicle used, countdowns can start from 72 to 96 hours before launch time.
During countdown:
Aerospace personnel bring the rocket vehicle to the launch site and load it with payload and propellants;
Launch-center computers communicate with sensors in the rocket, which monitor important systems on the launch vehicle and payload;
Launch personnel monitor the weather and wait for the launch window;
Security personnel prevent unauthorized persons from entering the "keep-out" area.
The procedures for each launch are written carefully. For the Space Shuttle, a five-volume set, Shuttle Countdown (KSC S0007), often referred to as "S0007", was used. Rosie Carver, a technical writer for United Launch Alliance, has created at least 15,000 procedures for more than 300 missions since the Solar Maximum Mission, which launched Feb. 14, 1980. These documents ar |
https://en.wikipedia.org/wiki/XF-73 | XF-73 (Exeporfinium chloride) is an experimental drug candidate. It is an anti-microbial that works via weakening bacteria cell walls. It is a potential treatment for methicillin-resistant Staphylococcus aureus (MRSA) and possibly Clostridium difficile. It is being developed by Destiny Pharma Ltd.
Structurally, it is a dicationic porphyrin.
It has completed a phase I clinical trial for nasal decolonisation of MRSA—being tested against 5 bacterial strains. It seems unlikely to cause MRSA to develop resistance to it.
In 2014, a phase 1 clinical trial for nasal administration was run.
, another phase 1 clinical trial (for nasal administration) completed recruiting in 2016 but no results have been posted. |
https://en.wikipedia.org/wiki/Surreal%20number | In mathematics, the surreal number system is a totally ordered proper class containing not only the real numbers but also infinite and infinitesimal numbers, respectively larger or smaller in absolute value than any positive real number. Research on the Go endgame by John Horton Conway led to the original definition and construction of surreal numbers. Conway's construction was introduced in Donald Knuth's 1974 book Surreal Numbers: How Two Ex-Students Turned On to Pure Mathematics and Found Total Happiness.
The surreals share many properties with the reals, including the usual arithmetic operations (addition, subtraction, multiplication, and division); as such, they form an ordered field. If formulated in von Neumann–Bernays–Gödel set theory, the surreal numbers are a universal ordered field in the sense that all other ordered fields, such as the rationals, the reals, the rational functions, the Levi-Civita field, the superreal numbers (including the hyperreal numbers) can be realized as subfields of the surreals. The surreals also contain all transfinite ordinal numbers; the arithmetic on them is given by the natural operations. It has also been shown (in von Neumann–Bernays–Gödel set theory) that the maximal class hyperreal field is isomorphic to the maximal class surreal field.
History of the concept
Research on the Go endgame by John Horton Conway led to the original definition and construction of the surreal numbers. Conway's construction was introduced in Donald Knuth's 1974 book Surreal Numbers: How Two Ex-Students Turned On to Pure Mathematics and Found Total Happiness. In his book, which takes the form of a dialogue, Knuth coined the term surreal numbers for what Conway had called simply numbers. Conway later adopted Knuth's term, and used surreals for analyzing games in his 1976 book On Numbers and Games.
A separate route to defining the surreals began in 1907, when Hans Hahn introduced Hahn series as a generalization of formal power series, and Ha |
https://en.wikipedia.org/wiki/T-structure | In the branch of mathematics called homological algebra, a t-structure is a way to axiomatize the properties of an abelian subcategory of a derived category. A t-structure on consists of two subcategories of a triangulated category or stable infinity category which abstract the idea of complexes whose cohomology vanishes in positive, respectively negative, degrees. There can be many distinct t-structures on the same category, and the interplay between these structures has implications for algebra and geometry. The notion of a t-structure arose in the work of Beilinson, Bernstein, Deligne, and Gabber on perverse sheaves.
Definition
Fix a triangulated category with translation functor . A t-structure on is a pair of full subcategories, each of which is stable under isomorphism, which satisfy the following three axioms.
If X is an object of and Y is an object of , then
If X is an object of , then X[1] is also an object of . Similarly, if Y is an object of , then Y[-1] is also an object of .
If A is an object of , then there exists a distinguished triangle such that X is an object of and Y is an object of .
It can be shown that the subcategories and are closed under extensions in . In particular, they are stable under finite direct sums.
Suppose that is a t-structure on . In this case, for any integer n, we define to be the full subcategory of whose objects have the form , where is an object of . Similarly, is the full subcategory of objects , where is an object of . More briefly, we define
With this notation, the axioms above may be rewritten as:
If X is an object of and Y is an object of , then
and .
If A is an object of , then there exists a distinguished triangle such that X is an object of and Y is an object of .
The heart or core of the t-structure is the full subcategory consisting of objects contained in both and , that is,
The heart of a t-structure is an abelian category (whereas a triangulated category is additive b |
https://en.wikipedia.org/wiki/OpenMediaVault | OpenMediaVault (OMV) is a free Linux distribution designed for network-attached storage (NAS). The project's lead developer is Volker Theile, who instituted it in 2009. OMV is based on the Debian operating system, and is licensed through the GNU General Public License v3.
Background
By the end of 2009, Volker Theile was the only active developer of FreeNAS, a NAS operating system that Olivier Cochard-Labbé started developing from m0n0wall in 2005. m0n0wall is a variation of the FreeBSD operating system, and Theile decided he wanted to rewrite FreeNAS for Linux. The project team had known for months that FreeNAS needed a major rewrite in order to support crucial features. Since Cochard-Labbé preferred to stay with a FreeBSD-based system, he and Theile agreed that Theile would develop his Linux version under a different name; that name was initially coreNAS, but within a matter of days Theile discarded it in favour of OpenMediaVault.
Meanwhile, FreeNAS still needed to be rewritten and maintained. To accomplish this, Cochard-Labbé handed development over to iXsystems, an American company that developed the TrueOS (Discontinued in 2020) operating system.
Technical design
Theile chose Debian because the large number of programs in its package management system meant that he wouldn't have to spend time repackaging software himself. OpenMediaVault makes a few changes to the Debian operating system. It provides a Web-based user interface for administration and customisation, and a plug-in API for implementing new features. One can install plug-ins through the Web interface.
Features
Multi-language, Web-based graphical user interface
Protocols: CIFS (via Samba), FTP, NFS (versions 3 and 4), SSH, rsync, iSCSI, AFP and TFTP
Software-RAID (levels 0, 1, 4, 5, 6, and 10, plus JBOD)
Monitoring: Syslog, Watchdog, S.M.A.R.T., SNMP (v1, 2c, and 3) (read-only)
Statistic reports via e-mail
Statistic graphs for the CPU-workload, LAN transfer rates, hard disk usage and RAM al |
https://en.wikipedia.org/wiki/Gdium | The Gdium is a subnotebook / netbook computer produced by EMTEC. The Gdium product is distinguished by its unique Loongson MIPS processor and the use of a USB key as a primary storage device. The Gdium netbook is marketed as an interface device to the Gdium "learning community"—a website that provides hardware support, MIPS builds of open-source software, Linux computing tips, and educational resources targeted towards teachers and students within the K-12 demographic.
Technical overview
The EMTEC Gdium Liberty 1000 is built on an STMicroelectronics Loongson 2F MIPS microprocessor and uses a proprietary form-factored USB key, called the G-Key, as its primary storage medium. The G-Key, which fits in a specially designed USB slot recessed within the unit, is available in 8GB and 16GB capacities. The key generates no noise, and is less susceptible to mechanical shock damage than hard drives. It also includes an SD card reader, which provides support for MMC, SD and SDHC cards as supplemental storage.
The Gdium uses Mandriva as its sole operating system and boots in approximately 30 seconds. The desktop uses the Metacity window manager with a lxplanel and idesk-based interface. Like most modern Linux distributions, open-source software applications such as OpenOffice.org, Mozilla Firefox, Thunderbird, and The GIMP are included in the default installation. There are no compilations of Microsoft Windows, OS X, or Ubuntu available for the MIPS architecture, but e.g. Debian offers packages compiled for MIPS.
The EMTEC Gdium Liberty 1000 specifications are as follows:
Screen size: 10" (254 mm)
Resolution: 1024 x 600
CPU: 900 MHz 64-bit Loongson 2F by STMicroelectronics
Operating system: Mandriva G-Linux
Video chipset: Silicon Motion SM502 (16MB dedicated video memory)
RAM: 512MB DDR2 (supports up to 1GB, not user upgradeable)
Primary Storage: 16GB to 32GB USB G-Key (removable)
Webcam: 0.3 or 1.3 Mpx
Keyboard: 240mm long and 96.8mm wide.
Wireless LAN: IEEE 802.11b/g
LAN: |
https://en.wikipedia.org/wiki/SYSV%20checksum | The SYSV checksum algorithm was a commonly used, legacy checksum algorithm.
It has been implemented in UNIX System V and is also available through the sum command line utility.
This algorithm is useless on a security perspective, and is weaker than the CRC-32 cksum for error detection.
Description of the algorithm
The main part of this algorithm is simply adding up all bytes in a 32-bit sum. As a result, this algorithm has the characteristics of a simple sum:
re-arranging the same bytes in another order (e.g. moving text from one place to another place) does not change the checksum.
increasing one byte and decreasing another byte by the same amount does not change the checksum.
adding or removing zero bytes does not change the checksum.
As a result, many common changes to text data are not detected by this method.
The FreeBSD pseudocode for this algorithm is:
s = sum of all bytes;
r = s % 2^16 + (s % 2^32) / 2^16;
cksum = (r % 2^16) + r / 2^16;
The last part folds the value into 16 bits. |
https://en.wikipedia.org/wiki/Mark%20Schnitzer | Mark Schnitzer is a Professor jointly in the Biology and Applied Physics departments at Stanford University and an Investigator of the Howard Hughes Medical Institute and is a recipient of a Paul Allen grant. His current research focuses on techniques for imaging individual neurons in vivo, including using fluorescent imaging and highly parallel processing techniques. In 2003, he was named to the MIT Technology Review's "TR100" list of young innovators. |
https://en.wikipedia.org/wiki/Brachyptery | Brachyptery is an anatomical condition in which an animal has very reduced wings. Such animals or their wings may be described as "brachypterous". Another descriptor for very small wings is microptery.
Brachypterous wings generally are not functional as organs of flight and often seem to be totally functionless and vestigial. In some species, however, flightless wings may have other functions, such as aposematic display in some Orthoptera and Phasmatodea. Brachyptery occurs commonly among insects. An insect species might evolve towards brachyptery by reducing its flight muscles and their associated energy demands, or by avoiding the hazards of flight in windy conditions on oceanic islands, in which flying insects are prone to drowning. Brachyptery also is common in ectoparasitic insects that have no use for wings, and inquiline insects with socially parasitic life strategies that do not require functional wings.
In some species of insects, brachyptery occurs in some members (say in only one sex, or only some castes), whereas fully functional wings occur in macropterous individuals. When brachyptery is sex-specific, females are often the sex with reduced wings, including reduced wing musculature. This may be to free energy for reproduction, or may be because some insect males (such as cockroaches) use their wings in courtship displays. Other forms of brachyptery may depend on the temperature at which the insect grew and developed. In winter, for example, some species of aphids grow reduced wings, whereas in summer they grow fully developed wings.
Some animals, like fleas and worker ants, display an extreme form of brachyptery called aptery, in which no wings grow at all.
See also
Aptery (no wings)
Flightless bird (including birds with reduced, ornamental or non-functional wings) |
https://en.wikipedia.org/wiki/Indian%20hedgehog%20%28protein%29 | Indian hedgehog homolog (Drosophila), also known as IHH, is a protein which in humans is encoded by the IHH gene. This cell signaling protein is in the hedgehog signaling pathway. The several mammalian variants of the Drosophila hedgehog gene (which was the first named) have been named after the various species of hedgehog; the Indian hedgehog is honored by this one. The gene is not specific to Indian hedgehogs.
Function
The Indian hedgehog protein is one of three proteins in the mammalian hedgehog family, the others being desert hedgehog (DHH) and sonic hedgehog (SHH). It is involved in chondrocyte differentiation, proliferation and maturation especially during endochondral ossification. It regulates its effects by feedback control of parathyroid hormone-related peptide (PTHrP).
Indian Hedge Hog, (Ihh) is one of three signaling molecules from the Hedgehog (Hh) gene family. Genes of the Hh family, Sonic Hedgehog (Shh), Desert Hedgehog (Dhh) and Ihh regulate several fetal developmental processes. The Ihh homolog is involved in the formation of chondrocytes during the development of limbs. The protein is released by small, non-proliferating, mature chondrocytes during endochondral ossification. Recently, Ihh mutations are shown to cause brachydactyly type A1 (BDA1), the first Mendelian autosomal dominant disorder in humans to be recorded. There are seven known mutations to Ihh that cause BDA1. Of particular interest, are mutations involving the E95 residue, which is thought to be involved with proper signaling mechanisms between Ihh and its receptors. In a mouse model, mice with mutations to the E95 residue were found to have abnormalities to their digits.
Ihh may also be involved in endometrial cell differentiation and implantation. Studies have shown progesterone to upregulate Ihh expression in the murine endometrium, suggesting a role in implantation. Ihh is suspected to be involved in the downstream regulation of other signaling molecules that are known to pla |
https://en.wikipedia.org/wiki/OR%20gate | The OR gate is a digital logic gate that implements logical disjunction. The OR gate outputs "true" if any of its inputs are "true"; otherwise it outputs "false". The input and output states are normally represented by different voltage levels.
Description
Any OR gate can be constructed with two or more inputs. It outputs a 1 if any of these inputs are 1, or outputs a 0 only if all inputs are 0. The inputs and outputs are binary digits ("bits") which have two possible logical states. In addition to 1 and 0, these states may be called true and false, high and low, active and inactive, or other such pairs of symbols.
Thus it performs a logical disjunction (∨) from mathematical logic. The gate can be represented with the plus sign (+) because it can be used for logical addition. Equivalently, an OR gate finds the maximum between two binary digits, just as the AND gate finds the minimum.
Together with the AND gate and the NOT gate, the OR gate is one of three basic logic gates from which any Boolean circuit may be constructed. All other logic gates may be made from these three gates; any function in binary mathematics may be implemented with them.
It is sometimes called the inclusive OR gate to distinguish it from XOR, the exclusive OR gate. The behavior of OR is the same as XOR except in the case of a 1 for both inputs. In situations where this never arises (for example, in a full-adder) the two types of gates are interchangeable. This substitution is convenient when a circuit is being implemented using simple integrated circuit chips which contain only one gate type per chip.
Symbols
There are two logic gate symbols currently representing the OR gate: the American (ANSI or 'military') symbol and the IEC ('European' or 'rectangular') symbol. The DIN symbol is deprecated.
The "≥1" on the IEC symbol indicates that the output is activated by at least one active input.
Hardware description and pinout
OR gates are basic logic gates, and are available in TTL and CMO |
https://en.wikipedia.org/wiki/Float%20voltage | Float voltage is the voltage at which a battery is maintained after being fully charged to maintain that capacity by compensating for self-discharge of the battery. The voltage could be held constant for the entire duration of the cell's operation (such as in an automotive battery) or could be held for a particular phase of charging by the charger. The appropriate float voltage varies significantly with the chemistry and construction of the battery, and ambient temperature.
With the appropriate voltage for the battery type and with proper temperature compensation, a float charger may be kept connected indefinitely without damaging the battery.
However, it should be understood that the concept of a float voltage does not apply equally to all battery chemistries. For instance, lithium ion cells have to be float charged with extra care because if they are float charged at just a little over optimum voltage, which is generally the full output voltage of the lithium cell, the chemical system within the cell will be damaged to some extent. Some lithium ion variants are less tolerant than others, but generally overheating, which shortens cell life is likely, and fire and explosion possible other outcomes. It is important to make certain that the battery cell involved can be safely float charged, and that in the absence of protection from a battery management system, that the charger circuit goes into float charge status when full charge is achieved.
Lead-acid batteries
Accepted average float voltages for lead-acid batteries at 25 °C can be found in following table:
Temperature compensation
Compensation per cell of approximately −3.9 mV/°C (−2.17 mV/°F) of temperature rise is necessary.
Example 1
A 12 V (6-cell) battery at 30 °C (86 °F) (+5 °C change):
Example 2
A 12 V (6-cell) battery at 20 °C (68 °F) (−5 °C change):
Not compensating for temperature will shorten battery life by over- or undercharging.
See also |
https://en.wikipedia.org/wiki/Goody%20Goody%20Gum%20Drops | Goody Goody Gum Drops is a New Zealand flavour of ice cream made by Tip Top. It is pastel green-coloured, bubble gum flavoured ice cream that is laced with gumdrops. It is considered iconic to New Zealand, and perception of the flavour is polarised among New Zealanders. Some people consider it to be a "national delicacy", while others consider it a "national disgrace".
History
Goody Goody Gum Drops was invented in 1983 by general director of Tip Top, Murray Taylor. According to Taylor, having a good distribution of gumdrops in the ice cream is difficult and "Very few ice-cream makers in the world would have attempted it".
In 2008, Tip Top created a variant of the ice cream flavour on a stick as a limited edition. At the time it was described as a technical triumph. According to Taylor, it took two years for the stick version to be created, due to distribution of the gumdrops being a problem. At first they all came out as a big lump, and Danish consultants created a mathematical model of the normal distribution of the gumdrops, saying that the goal could not be achieved. To mark the launch of the product, a television advertising campaign starting from 16 November saw 'Goody' and 'Stick' fall in love at a supermarket checkout. Their romance included a candle-lit dinner, ice cream at the beach, and an "encounter for Stick with a low-hanging branch on a bike ride through the countryside". The stick ice cream came back to stores in 2019, this time larger in size, compared to the original . Tip Top's Facebook post announcing the return gathered 1,600 comments in a day.
In November 2008, it was reported that, for the year, consumers had consumed 50 million gumdrops in the ice cream. In 2016, TipTop collaborated with Griffin's to create a Goody Goody Gum Drop flavour of the Griffin's Squiggles biscuit. In December 2017, Goody Goody Gum Drops "started to disappear" from stores and later returned. In 2019, Primo, a flavoured milk producer, created a Goody Goody Gum Dro |
https://en.wikipedia.org/wiki/Visual%20artifact | Visual artifacts (also artefacts) are anomalies apparent during visual representation as in digital graphics and other forms of imagery, especially photography and microscopy.
In digital graphics
Image quality factors, different types of visual artifacts
Compression artifacts
Digital artifacts, visual artifacts resulting from digital image processing
Noise
Screen-door effect, also known as fixed-pattern noise (FPN), a visual artifact of digital projection technology
Ghosting (television)
Screen burn-in
Distortion
Silk screen effect
Rainbow effect
Screen tearing
Moiré pattern
Color banding
In video entertainment
Many people who use their computers as a hobby experience artifacting due to a hardware or software malfunction. The cases can differ but the usual causes are:
Temperature issues, such as failure of cooling fan.
Unsuited video card (graphics card) drivers.
Drivers that have values that the graphics card is not suited with.
Overclocking beyond the capabilities of the particular video card.
Software bugs in the application or operating system.
The differing cases of visual artifacting can also differ between scheduled task(s).
In photography
These effects can occur in both analog and digital photography.
Chromatic aberration due to optical dispersion through a lens, leading to color fringes at high-contrast boundaries in a photograph
Purple fringing
Motion blur
Near-camera reflection, visual artifacts caused by the backscatter of light by unfocused particles
In microscopy
In microscopy, an artifact is an apparent structural detail that is caused by the processing of the specimen and is thus not a legitimate feature of the specimen. In light microscopy, artifacts may be produced by air bubbles trapped under the slide's cover slip.
In electron microscopy, distortions may be produced in the drying out of the specimen. Staining can cause the appearance of solid chemical deposits that may be seen as structures inside the cell. Different |
https://en.wikipedia.org/wiki/Integrin%20alpha%202 | Integrin alpha-2, or CD49b (cluster of differentiation 49b), is a protein which in humans is encoded by the CD49b gene.
The CD49b protein is an integrin alpha subunit. It makes up half of the α2β1 integrin duplex. Integrins are heterodimeric integral membrane glycoproteins composed of a distinct alpha chain and a common beta chain. They are found on a wide variety of cell types including T cells (the NKT cells), NK cells, fibroblasts and platelets. Integrins are involved in cell adhesion and also participate in cell-surface-mediated signalling.
Expression of CD49b in conjunction with LAG-3 has been used to identify type 1 regulatory (Tr1) cells.
The DX5 monoclonal antibody recognizes mouse CD49b.
Interactions
CD49b has been shown to interact with MMP1. |
https://en.wikipedia.org/wiki/Intestinal%20infectious%20diseases | Intestinal infectious diseases include a large number of infections of the bowels including: cholera, typhoid fever, paratyphoid fever, other types of salmonella infections, shigellosis, botulism, gastroenteritis, and amoebiasis among others.
Typhoid and paratyphoid resulted in 221,000 deaths in 2013 down from 259,000 deaths in 1990. Other diseases which result in diarrhea caused another 1.3 million additional deaths in 2013 down from 2.6 million deaths in 1990. |
https://en.wikipedia.org/wiki/Linux%20console | The Linux console is a system console internal to the Linux kernel. A system console is the device which receives all kernel messages and warnings and which allows logins in single user mode. The Linux console provides a way for the kernel and other processes to send text output to the user, and to receive text input from the user. The user typically enters text with a computer keyboard and reads the output text on a computer monitor. The Linux kernel supports virtual consoles – consoles that are logically separate, but which access the same physical keyboard and display. The Linux console (and Linux virtual consoles) are implemented by the VT (virtual terminal) subsystem of the Linux kernel, and do not rely on any user space software. This is in contrast to a terminal emulator, which is a user space process that emulates a terminal, and is typically used in a graphical display environment.
The Linux console was one of the first features of the kernel and was originally written by Linus Torvalds in 1991 (see history of Linux). There are two main implementations: framebuffer and text mode. The framebuffer implementation is the default in modern Linux distributions, and together with kernel mode setting, provides kernel-level support for display hardware and features such as showing graphics while the system is booting. The legacy text mode implementation was used in PC-compatible systems with CGA, EGA, MDA and VGA graphics cards. Non-x86 architectures used framebuffer mode because their graphics cards did not implement text mode. The Linux console uses fixed-size bitmap, monospace fonts, usually defaulting to 8x16 pixels per character.
The Linux console is an optional kernel feature, and most embedded Linux systems do not enable it. These systems typically provide an alternative user interface (e.g. web based), or boot immediately into a graphical user interface and use this as the primary means of interacting with the user. Other implementations of the Linux conso |
https://en.wikipedia.org/wiki/Vector%20radiative%20transfer | In spectroscopy and radiometry, vector radiative transfer (VRT) is a method of modelling the propagation of polarized electromagnetic radiation in low density media. In contrast to scalar radiative transfer (RT), which models only the first Stokes component, the intensity, VRT models all four components through vector methods.
For a single frequency, , the VRT equation for a scattering media can be written as follows:
where s is the path, is the propagation vector, K is the extinction matrix, is the absorption vector, B is the Planck function and Z is the scattering phase matrix.
All the coefficient matrices, K, and Z, will vary depending on the density of absorbers/scatterers present and must be calculated from their density-independent quantities, that is the attenuation coefficient vector, , is calculated from the mass absorption coefficient vector times the density of the absorber.
Moreover, it is typical for media to have multiple species causing extinction, absorption and scattering, thus these coefficient matrices must be summed up over all the different species.
Extinction is caused both by simple absorption as well as from scattering out of the line-of-sight, , therefore we calculate the extinction matrix from the combination of the absorption vector and the scattering phase matrix:
where I is the identity matrix.
The four-component radiation vector, where I, Q, U and V are the first through fourth elements of the Stokes parameters, respectively, fully describes the polarization state of the electromagnetic radiation.
It is this vector-nature that considerably complicates the equation.
Absorption will be different for each of the four components, moreover, whenever the radiation is scattered, there can be a complex transfer between the different Stokes components—see polarization mixing—thus the scattering phase function has 4*4=16 components. It is, in fact, a rank-two tensor. |
https://en.wikipedia.org/wiki/List%20of%20cluster%20management%20software | List of software for cluster management.
Free and open source
HA
Apache Mesos, from the Apache Software Foundation
Kubernetes, founded by Google Inc, from the Cloud Native Computing Foundation
Heartbeat, from Linux-HA
Docker Swarm
Red Hat cluster suite
OpenShift and OKD, from Red Hat
Nomad, from HashiCorp
Rancher, from Rancher Labs
TrinityX from ClusterVision Solutions
Corosync Cluster Engine
OpenSVC
K3s (“Lightweight Kubernetes“), from Rancher Labs
non-HA
oneSIS
OpenHPC
OpenSAF, founded by Motorola, from OpenSAF Foundation, implements Service Availability Forum
Rocks Cluster Distribution
Stacki, from StackIQ
YARN, distributed with Apache Hadoop
xCAT
Warewulf
Foreman
Proprietary
Amazon Elastic Container Service
Borg, used at Google
Bright Cluster Manager, from Bright Computing
CycleCloud, from Cycle Computing acquired By Microsoft
IBM Tivoli System Automation for Multiplatforms, from IBM
Microsoft Cluster Server, from Microsoft
Twine, from Facebook
HPE Performance Cluster Manager - HPCM, from Hewlett Packard Enterprise Company
Dell/EMC - Remote Cluster Manager (RCM)
Aspen Systems Inc - Aspen Cluster Management Environment (ACME)
Evidian SafeKit
IBM PowerHA system mirror
Veritas Cluster Server
See also
Comparison of cluster software |
https://en.wikipedia.org/wiki/Boy%27s%20surface | In geometry, Boy's surface is an immersion of the real projective plane in 3-dimensional space found by Werner Boy in 1901. He discovered it on assignment from David Hilbert to prove that the projective plane could not be immersed in 3-space.
Boy's surface was first parametrized explicitly by Bernard Morin in 1978. Another parametrization was discovered by Rob Kusner and Robert Bryant. Boy's surface is one of the two possible immersions of the real projective plane which have only a single triple point.
Unlike the Roman surface and the cross-cap, it has no other singularities than self-intersections (that is, it has no pinch-points).
Parametrization
Boy's surface can be parametrized in several ways. One parametrization, discovered by Rob Kusner and Robert Bryant, is the following: given a complex number w whose magnitude is less than or equal to one (), let
and then set
we then obtain the Cartesian coordinates x, y, and z of a point on the Boy's surface.
If one performs an inversion of this parametrization centered on the triple point, one obtains a complete minimal surface with three ends (that's how this parametrization was discovered naturally). This implies that the Bryant–Kusner parametrization of Boy's surfaces is "optimal" in the sense that it is the "least bent" immersion of a projective plane into three-space.
Property of Bryant–Kusner parametrization
If w is replaced by the negative reciprocal of its complex conjugate, then the functions g1, g2, and g3 of w are left unchanged.
By replacing in terms of its real and imaginary parts , and expanding resulting parameterization, one may obtain a parameterization of Boy's surface in terms of rational functions of and . This shows that Boy's surface is not only an algebraic surface, but even a rational surface. The remark of the preceding paragraph shows that the generic fiber of this parameterization consists of two points (that is that almost every point of Boy's surface may be obtained by two |
https://en.wikipedia.org/wiki/Surfactant%20protein%20C | Surfactant protein C (SP-C), is one of the pulmonary surfactant proteins. In humans this is encoded by the SFTPC gene.
It is a membrane protein.
Structure
SFTPC is a 197-residue protein made up of two halves: a unique N-terminal propeptide domain and a C-terminal BRICHOS domain. The around 100-aa long propeptide domain actually contains not only the cleaved part, but also the mature peptide. It can be further broken down into a 23-aa helical transmembrane propeptide proper, the mature secreted SP-C (24-58), and a linker (59-89) that connects to the BRICHOS domain.
The propeptide of pulmonary surfactant C has an N-terminal alpha-helical segment whose suggested function was stabilization of the protein structure, since the mature peptide can irreversibly transform from its native alpha-helical structure to beta-sheet aggregates and form amyloid fibrils. The correct intracellular trafficking of proSP-C has also been reported to depend on the propeptide.
The structure of the BRICHOS domain has been solved. Mutations in this domain also lead to amyloid fibrils made up of the mature peptide, suggesting a chaperone activity.
Clinical significance
Mutations are associated with surfactant metabolism dysfunction type 2.
Humans and animals born lacking SP-C tend to develop progressive interstitial lung disease.
Recombinant SP-C is used in Venticute, an artificial lung surfactant.
A process to mass-produce an analogue called rSP-C33Le by fusion with spidroin has been described. |
https://en.wikipedia.org/wiki/NCAPD2 | Condensin complex subunit 1 also known as chromosome-associated protein D2 (CAP-D2) or non-SMC condensin I complex subunit D2 (NCAPD2) or XCAP-D2 homolog is a protein that in humans is encoded by the NCAPD2 gene. CAP-D2 is a subunit of condensin I, a large protein complex involved in chromosome condensation. |
https://en.wikipedia.org/wiki/Anterior%20corticospinal%20tract | The anterior corticospinal tract (also called the ventral corticospinal tract, "Bundle of Turck", medial corticospinal tract, direct pyramidal tract, or anterior cerebrospinal fasciculus) is a small bundle of descending fibers that connect the cerebral cortex to the spinal cord. Descending tracts are pathways by which motor signals are sent from upper motor neurons in the brain to lower motor neurons which then directly innervate muscle to produce movement. The anterior corticospinal tract is usually small, varying inversely in size with the lateral corticospinal tract, which is the main part of the corticospinal tract.
It lies close to the anterior median fissure, and is present only in the upper part of the spinal cord; gradually diminishing in size as it descends, it ends about the middle of the thoracic region.
It consists of descending fibers that arise from cells in the motor area of the ipsilateral cerebral hemisphere. The impulse travels from these upper motor neurons (located in the pre-central gyrus of the brain) through the anterior column. In contrast to the fibers for the lateral corticospinal tract, the fibers for the anterior corticospinal tract do not decussate at the level of the medulla oblongata, although they do cross over in the spinal level they innervate. They then synapse at the anterior horn with the lower motor neuron which then synapses with the target muscle at the motor end plate. In contrast to the lateral corticospinal tract which controls the movement of the limbs, the anterior corticospinal tract controls the movements of axial muscles (of the trunk).
A few of its fibers pass to the lateral column of the same side and to the gray matter at the base of the posterior grey column.
Additional images |
https://en.wikipedia.org/wiki/Mailpile | Mailpile is a free and open-source email client with the main focus of privacy and usability. It is a webmail client, albeit one run from the user's computer, as a downloaded program launched as a local website.
Features
In the default setup of the program, the user is given a public and a private PGP key, for the purpose of (respectively) receiving encrypted email and then decrypting it. Mailpile uses PGP and stores all locally generated files in encrypted form on-disk. The client takes an opportunistic approach to finding other users to encrypt to, those that support it, and integrates this in the process of sending email.
The program preloads a lot of email data into RAM to accelerate search results. While the search results remain really fast despite large amounts of emails, this gradually slows down the start-up time of the program as stored email data increases. This feature will likely be altered in the planned Mailpile version 2.
History
Mailpile started out as a search engine in 2011.
Crowdfunding
The project gained recognition following an Indiegogo crowdfunding campaign, raising $163,192 between August and September 2013. In the middle of the campaign, PayPal froze a large portion of the raised funds, and subsequently released them after Mailpile took the issue to the public on blogs and social media platforms including Twitter.
Releases
Alpha
The first publicly tagged release 0.1.0 from January 2014 included an original typeface (also by the name of "Mailpile"), UI feedback of encryption and signatures, custom search engine, integrated spam-filtering support, and localization to around 30 languages.
Alpha II
July 2014 This release introduced storing logs encrypted, partial native IMAP support, and the spam filtering engine gained more ways to auto-classify e-mail. The graphical interface was revamped. A wizard was introduced to help users with account setup.
Beta
Mailpile released a beta version in September 2014.
Beta II
January 2015
|
https://en.wikipedia.org/wiki/Harvard%20Mark%20IV | The Harvard Mark IV was an electronic stored-program computer built by Harvard University under the supervision of Howard Aiken for the United States Air Force. The computer was finished being built in 1952. It stayed at Harvard, where the Air Force used it extensively.
The Mark IV was all electronic. The Mark IV used magnetic drum and had 200 registers of ferrite magnetic-core memory (one of the first computers to do so). It separated the storage of data and instructions in what is now sometimes referred to as the Harvard architecture although that term was not coined until the 1970s (in the context of microcontrollers).
See also
Harvard Mark I
Harvard Mark II
Harvard Mark III
List of vacuum-tube computers
Howard Aiken
Harvard (World War II advanced trainer aircraft) |
https://en.wikipedia.org/wiki/Supine%20position | The supine position ( or ) means lying horizontally with the face and torso facing up, as opposed to the prone position, which is face down. When used in surgical procedures, it grants access to the peritoneal, thoracic and pericardial regions; as well as the head, neck and extremities.
Using anatomical terms of location, the dorsal side is down, and the ventral side is up, when supine.
Semi-supine
In scientific literature "semi-supine" commonly refers to positions where the upper body is tilted (at 45° or variations) and not completely horizontal.
Relation to sudden infant death syndrome
The decline in death due to sudden infant death syndrome (SIDS) is said to be attributable to having babies sleep in the supine position. The realization that infants sleeping face down, or in a prone position, had an increased mortality rate re-emerged into medical awareness at the end of the 1980s when two researchers, Susan Beal in Australia and Gus De Jonge in the Netherlands, independently noted the association.
It is believed that in the prone position babies are more at risk to re-breathe their own carbon dioxide. Because of the immature state of their central chemoreceptors, infants do not respond to the subsequent respiratory acidosis that develops. Typical non-infants realize autonomic responses of increased rate and depth of respiration (hyperventilation, yawning).
Obstructive sleep apnea
Obstructive sleep apnea (OSA) is a form of sleep apnea that occurs more frequently when throat muscles relax and is most severe when individuals are sleeping in the supine position. Studies and evidence show that OSA related to sleeping in the supine position is related to the airway positioning, reduced lung volume, and the inability of airway muscles to dilate enough to compensate as the airway collapses. With individuals who have OSA, many health care providers encourage their patients to avoid the supine position while asleep and sleep laterally or sleep with the head of th |
https://en.wikipedia.org/wiki/Extracellular%20vesicle | Extracellular vesicles (EVs) are lipid bilayer-delimited particles that are naturally released from almost all types of cells but, unlike a cell, cannot replicate. EVs range in diameter from near the size of the smallest physically possible unilamellar liposome (around 20-30 nanometers) to as large as 10 microns or more, although the vast majority of EVs are smaller than 200 nm. EVs can be divided according to size and synthesis route into exosomes, microvesicles and apoptotic bodies. They carry a cargo of proteins, nucleic acids, lipids, metabolites, and even organelles from the parent cell. EVs carry distinct proteo-transcriptomic signatures that are different from their cancer cell of origin. Most cells that have been studied to date are thought to release EVs, including some archaeal, bacterial, fungal, and plant cells that are surrounded by cell walls. A wide variety of EV subtypes have been proposed, defined variously by size, biogenesis pathway, cargo, cellular source, and function, leading to a historically heterogenous nomenclature including terms like exosomes and ectosomes.
Numerous functions of EVs have been established or postulated. The first evidence for the existence of EVs was enabled by the ultracentrifuge, the electron microscope, and functional studies of coagulation in the mid-20th century. A sharp increase in interest in EVs occurred in the first decade of the 21st century following the discovery that EVs could transfer nucleic acids such as RNA from cell to cell. Associated with EVs from certain cells or tissues, nucleic acids could be easily amplified as markers of disease and also potentially traced back to a cell of origin, such as a tumor cell. When EVs are taken up by other cells, they may alter the behaviour of the recipient cell, for instance EVs released by colorectal cancer cells increase migration of fibroblasts and thus EVs are of importance in forming tumour landscapes. This discovery also implied that EVs could be used for thera |
https://en.wikipedia.org/wiki/NCOS | NCOS is the graphical user interface-based operating system developed for use in Oracle Corporation's Network Computers, which are discontinued. It was adapted by Acorn Computers from its own , which was originally developed for their range of Archimedes desktop computers. It shares with the same 4 MB ROM size and suitability for use with TV displays.
In 1999, Pace acquired the set-top box (STB) division of Acorn Computers, this being a component in the disposal of assets around the takeover of Acorn by MSDW Investment Holdings. This gave Pace the rights to use and develop NCOS. RISCOS Ltd later announced Embedded RISC OS, which was to have similarities with NCOS.
Development
NCOS originated in connection with the Network Computer project. It was used on various STB products. It branched from RISC OS 3.60 and was called RISC OS 3.61 before being named after Network Computer Operating System. It was merged back into the HEAD whilst at Pace, where it was known as and RO-STB.
Features
NCOS was designed in accord with the Network Computer Reference Profile and thus supports internet standards of the time. Being closely based on , it can also run many of that operating system's applications. Reporting on the launch of the Network Computer in 1996, it was noted that NCOS was essentially the same as RISC OS but with some features removed, such as "support for local file systems", whereas other features such as network support had been added to ROM. The actual differences involved the absence of "modules significant to the operation and networking" of existing RISC OS versions, including the Filer, TaskManager and Pinboard modules, plus a range of networking modules. The use of files stored on a server and accessed using the Network File System (NFS) also imposed restrictions on the files used by applications, with recommended techniques for the deployment of applications involving the transfer of files over NFS from RISC OS clients or the use of archives in the larg |
https://en.wikipedia.org/wiki/Robert%20Fortet | Robert Fortet (1 May 1912, Boulazac, France – 3 July 1998, Paris) was a French mathematician working on analysis. His doctoral advisor was Maurice René Fréchet.
Fortet was a professor at the University of Caen and at the University of Paris. Some of his Ph.D. students in Paris were Egon Balas, Jyotiprasad Medhi and Jacques Neveu. |
https://en.wikipedia.org/wiki/Kabat%20numbering%20scheme | The Kabat numbering scheme is a scheme for the numbering of amino acid residues in antibodies based upon variable regions. The scheme is useful when comparing these variable regions between antibodies. Its foundations were laid by the American biomedical scientist Elvin A. Kabat, who started collecting and aligning amino acid sequences of human and mouse Bence Jones proteins and immunoglobulin light chains in 1969.
Another numbering scheme is the Chothia numbering system.
History
The basis for the Kabat numbering scheme was laid out by a 1970s paper aligning 77 Bence-Jones protein sequences. This analysis showed signals of "10 invariant and almost invariant glycines" as well as signals of hypervariable regions. Kabat produced the first numbering scheme in 1970.
The KabatMan (Kabat Sequence Database) is a database collecting antibody sequences. |
https://en.wikipedia.org/wiki/Event%20%28particle%20physics%29 | In particle physics, an event refers to the results just after a fundamental interaction takes place between subatomic particles, occurring in a very short time span, at a well-localized region of space. Because of the uncertainty principle, an event in particle physics does not have quite the same meaning as it does in the theory of relativity, in which an "event" is a point in spacetime which can be known exactly, i.e., a spacetime coordinate.
Overview
In a typical particle physics event, the incoming particles are scattered or destroyed, and up to hundreds of particles can be produced, although few are likely to be new particles not discovered before.
In the old bubble chambers and cloud chambers, "events" could be seen by observing charged particle tracks emerging from the region of the event before they curl due to the magnetic field through the chamber acting on the particles. At modern particle accelerators, events are the result of the interactions which occur from a beam crossing inside a particle detector.
Physical quantities used to analyze events include the differential cross section, the flux of the beams (which in turn depends on the number density of the particles in the beam and their average velocity), and the rate and luminosity of the experiment.
Individual particle physics events are modeled by scattering theory based on an underlying quantum field theory of the particles and their interactions. The S-matrix is used to characterize the probability of various event outgoing particle states given the incoming particle states. For suitable quantum field theories, the S-matrix may be calculated by a perturbative expansion in terms of Feynman diagrams.
Events occur naturally in astrophysics and geophysics, such as subatomic particle showers produced from cosmic ray scattering events. |
https://en.wikipedia.org/wiki/Algorithmic%20technique | In mathematics and computer science, an algorithmic technique is a general approach for implementing a process or computation.
General techniques
There are several broadly recognized algorithmic techniques that offer a proven method or process for designing and constructing algorithms. Different techniques may be used depending on the objective, which may include searching, sorting, mathematical optimization, constraint satisfaction, categorization, analysis, and prediction.
Brute force
Brute force is a simple, exhaustive technique that evaluates every possible outcome to find a solution.
Divide and conquer
The divide and conquer technique decomposes complex problems recursively into smaller sub-problems. Each sub-problem is then solved and these partial solutions are recombined to determine the overall solution. This technique is often used for searching and sorting.
Dynamic
Dynamic programming is a systematic technique in which a complex problem is decomposed recursively into smaller, overlapping subproblems for solution. Dynamic programming stores the results of the overlapping sub-problems locally using an optimization technique called memoization.
Evolutionary
An evolutionary approach develops candidate solutions and then, in a manner similar to biological evolution, performs a series of random alterations or combinations of these solutions and evaluates the new results against a fitness function. The most fit or promising results are selected for additional iterations, to achieve an overall optimal solution.
Graph traversal
Graph traversal is a technique for finding solutions to problems that can be represented as graphs. This approach is broad, and includes depth-first search, breadth-first search, tree traversal, and many specific variations that may include local optimizations and excluding search spaces that can be determined to be non-optimum or not possible. These techniques may be used to solve a variety of problems including shortest path and con |
https://en.wikipedia.org/wiki/Unit%20disk%20graph | In geometric graph theory, a unit disk graph is the intersection graph of a family of unit disks in the Euclidean plane. That is, it is a graph with one vertex for each disk in the family, and with an edge between two vertices whenever the corresponding vertices lie within a unit distance of each other.
They are commonly formed from a Poisson point process, making them a simple example of a random structure.
Definitions
There are several possible definitions of the unit disk graph, equivalent to each other up to a choice of scale factor:
Unit disk graphs are the graph formed from a collection of points in the Euclidean plane, with a vertex for each point and an edge connecting each pair of points whose distance is below a fixed threshold.
Unit disk graphs are the intersection graphs of equal-radius circles, or of equal-radius disks. These graphs have a vertex for each circle or disk, and an edge connecting each pair of circles or disks that have a nonempty intersection.
Unit disk graphs may be formed in a different way from a collection of equal-radius circles, by connecting two circles with an edge whenever one circle contains the center of the other circle.
Properties
Every induced subgraph of a unit disk graph is also a unit disk graph. An example of a graph that is not a unit disk graph is the star with one central node connected to six leaves: if each of six unit disks touches a common unit disk, some two of the six disks must touch each other. Therefore, unit disk graphs cannot contain an induced subgraph. Infinitely many other forbidden induced subgraphs are known.
The number of unit disk graphs on labeled vertices is within an exponential factor of . This rapid growth implies that unit disk graphs do not have bounded twin-width.
Applications
Beginning with the work of , unit disk graphs have been used in computer science to model the topology of ad hoc wireless communication networks. In this application, nodes are connected through a direct wire |
https://en.wikipedia.org/wiki/Dreambox | Dreambox is a series of Linux-powered DVB satellite, terrestrial and cable digital television receivers (set-top boxes), produced by German multimedia vendor Dream Multimedia.
History and description
The Linux-based production software originally used by Dreambox was originally developed for DBox2, by the Tuxbox project. The Dbox2 was a proprietary design distributed by KirchMedia for their pay TV services. The bankruptcy of KirchMedia flooded the market with unsold boxes available for Linux enthusiasts. The Dreambox shares the basic design of the DBox2, including the Ethernet port and the PowerPC processor.
Its firmware is officially user-upgradable, since it is a Linux-based computer, as opposed to third-party "patching" of alternate receivers. All units support Dream's own DreamCrypt conditional access (CA) system, with software-emulated CA Modules (CAMs) available for many alternate CA systems. The built-in Ethernet interface allows networked computers to access the recordings on the internal hard disks on some Dreambox models. It also enables the receiver to store digital copies of DVB MPEG transport streams on distributed file systems or broadcast the streams as IPTV to VideoLAN and XBMC Media Center clients. Unlike many PC based PVR systems that use free-to-air type of DVB receiver cards, the built-in conditional access allows receiving and storing encrypted content.
In 2007, Dream Multimedia also introduced a non-Linux based Dreambox receiver, the DM100, their sole to date, still featuring an Ethernet port. It has a USB-B port for service instead of the RS-232 or mini-USB connectors found on other models. Unlike all other Dreamboxes, it features an STMicroelectronics CPU instead of PowerPC or MIPS.
Dreambox models
There are a number of different models of Dreambox available. The numbers are suffixed with -S for Satellite, -T for Terrestrial and -C for Cable:
Table
**HDMI via DVI to HDMI adapter.
Remark: The new 7020hd v2 has a new Flash with anoth |
https://en.wikipedia.org/wiki/Topincs | Topincs is a software for rapid development of web databases and web applications. It is based on LAMP and the semantic technology Topic Maps. A Topincs web database makes information accessible through browsing very much like a Wiki. Editing a page on a subject is done through forms rather than markup editing. A web database can be tailored into a web application to provide specific user groups a contextualized approach to the data.
All modeling and development tasks are performed in the web browser. No other development tools are necessary. The server requires Apache, MySQL and PHP. The client works on any standards-compliant web browser on desktops, laptops, tablets, and mobile phones. The layout is automatically adjusted to smaller screens.
The programmatic access to data is done via a virtual object-oriented programming interface which is set up over the schema in a few minutes. It is interpreted rather than generated. Portions of the database can be pulled into memory to accelerate bulk access.
Features
Browseable data
High-quality web forms
Little to no programming
Development done in the browser, no other tools required
Client runs in any standard-compliant web browser
Virtual object-oriented programming interface
User interface adjusts to screen size
Supports desktops, laptops, tablets, and mobile phones
Flexible data modeling
Challenges
Requires rethinking the development process and dropping many hard learned habits
Requires a familiarity with two ISO standards ISO 13259 and 19756
Forms cannot be easily adjusted in layout and behavior
Server installation difficult and prone to error
License
Topincs can be used in a private network for any purpose for free. The use in a public network is restricted to non-commercial applications.
See also
Topic Maps
Rapid application development
Metamodeling |
https://en.wikipedia.org/wiki/Descartes%20number | In number theory, a Descartes number is an odd number which would have been an odd perfect number if one of its composite factors were prime. They are named after René Descartes who observed that the number would be an odd perfect number if only were a prime number, since the sum-of-divisors function for would satisfy, if 22021 were prime,
where we ignore the fact that 22021 is composite ().
A Descartes number is defined as an odd number where and are coprime and , whence is taken as a 'spoof' prime. The example given is the only one currently known.
If is an odd almost perfect number, that is, and is taken as a 'spoof' prime, then is a Descartes number, since . If were prime, would be an odd perfect number.
Properties
Banks et al. showed in 2008 that if is a cube-free Descartes number not divisible by , then has over a million distinct prime divisors.
Tóth showed in 2021 that if denotes a Descartes number (other than Descartes’ example), with pseudo-prime factor , then .
Generalizations
John Voight generalized Descartes numbers to allow negative bases. He found the example . Subsequent work by a group at Brigham Young University found more examples similar to Voight's example, and also allowed a new class of spoofs where one is allowed to also not notice that a prime is the same as another prime in the factorization.
See also
Erdős–Nicolas number, another type of almost-perfect number
Notes |
https://en.wikipedia.org/wiki/Bipolar%20neuron | A bipolar neuron, or bipolar cell, is a type of neuron that has two extensions (one axon and one dendrite). Many bipolar cells are specialized sensory neurons for the transmission of sense. As such, they are part of the sensory pathways for smell, sight, taste, hearing, touch, balance and proprioception. The other shape classifications of neurons include unipolar, pseudounipolar and multipolar. During embryonic development, pseudounipolar neurons begin as bipolar in shape but become pseudounipolar as they mature.
Common examples are the retina bipolar cell, the ganglia of the vestibulocochlear nerve, the extensive use of bipolar cells to transmit efferent (motor) signals to control muscles, olfactory receptor neurons in the olfactory epithelium for smell (axons form the olfactory nerve), and neurons in the spiral ganglion for hearing (CN VIII).
In the retina
Often found in the retina, bipolar cells are crucial as they serve as both direct and indirect cell pathways. The specific location of the bipolar cells allow them to facilitate the passage of signals from where they start in the receptors to where they arrive at the amacrine and ganglion cells. Bipolar cells in the retina are also unusual in that they do not fire impulses like the other cells found within the nervous system. Rather, they pass the information by graded signal changes. Bipolar cells come in two varieties, having either an on-center or an off-center receptive field, each with a surround of the opposite sign. The off-center bipolar cells have excitatory synaptic connections with the photoreceptors, which fire continuously in the dark and are hyperpolarized (suppressed) by light. The excitatory synapses thus convey a suppressive signal to the off-center bipolar cells. On-center bipolar cells have inhibitory synapses with the photoreceptors and therefore are excited by light and suppressed in the dark.
In the vestibular nerve
Bipolar neurons exist within the vestibular nerve as it is responsibl |
https://en.wikipedia.org/wiki/Intermediate%20power%20amplifier | An Intermediate power amplifier (IPA) is one stage of the amplification process in a radio transmitter which usually occurs prior to the final high power amplification. The IPA provides lower power RF energy necessary to drive the final. In very high power transmitters, such as 10 kilowatts and above, multiple IPAs are combined to provide enough drive for the final.
An exciter, an even lower power transmitter, provides a similar service to the IPA by driving it; although an exciter usually encompasses other important functions, such as choosing the frequency of the RF. |
https://en.wikipedia.org/wiki/Bionic%20architecture | Bionic architecture is a contemporary movement that studies the physiological, behavioural, and structural adaptions of biological organisms as a source of inspiration for designing and constructing expressive buildings. These structures are designed to be self-sufficient, being able to structurally modify themselves in response to the fluctuating internal and external forces such as changes in weather and temperature.
Although this style of architecture has existed since the early 18th century period, the movement only began to mature in the early 21st century, following society's growing concerns over climate change and global warming. These influences led to bionic architecture being used to draw society away from its anthropocentric environment, by creating landscapes that allow for the harmonious relationship between nature and society. This is achieved through having an in-depth understanding of the complex interactions between form, material, and structure in order to ensure that the building's design supports a more sustainable environment. As a result, architects will rely upon the use of high-tech, artificial materials and techniques in order to conserve energy and materials, lower the consumption of construction and increase the practicality and reliability of their building structures.
History and theoretical framework
The word ‘bionic architecture’ is derived from the Greek word ‘bios’ (life) as well as the English word ‘technics’ (to study). The term was originally used to describe the scientific trend of ‘transferring technologies into life-forms’. The term ‘bionic’ was first used in 1958 by U.S army colonel, Jack E. Steele and Soviet scientist, Otto Schmitt during an astronomer project that focused on research surrounding the field of robotics. In their project, both researchers initially recognised the concept of bionics as ‘the science of systems based on living creatures’. The idea was then expanded upon in 1997 by Janine Benyus, who coined the |
https://en.wikipedia.org/wiki/OKATO | Russian Classification on Objects of Administrative Division (), or OKATO (), also called All-Russian classification on units of administrative and territorial distribution in English, is one of several Russian national registers. OKATO's purpose is organization of information about structure of the administrative divisions of the federal subjects of Russia.
The document assigns numeric codes to each administrative division of the country, which are hierarchically structured from the federal subject level down to selsoviet level; an expanded version also includes listings of individual inhabited localities within each administrative division.
OKATO is used for statistical and tax purposes. It was adopted on July 31, 1995, replacing SOATO (Designation System of Objects of Administrative Division of the Union of SSR and the Union Republics, as well as Inhabited Localities). It went into effect on January 1, 1997 and as of 2014 underwent 243 revisions. The compilation and maintenance of the OKATO data are the responsibility of the Federal State Statistics Service of Russia (Rosstat).
See also
Administrative division codes of the People's Republic of China (:zh:中华人民共和国行政区划代码), a somewhat similar system used in the PRC (only down to the county level).
OKTMO, Russian Classification on Territories of Municipal Division |
https://en.wikipedia.org/wiki/Walker%20motifs | The Walker A and Walker B motifs are protein sequence motifs, known to have highly conserved three-dimensional structures. These were first reported in ATP-binding proteins by Walker and co-workers in 1982.
Of the two motifs, the A motif is the main "P-loop" responsible for binding phosphate, while the B motif is a much less conserved downstream region. The P-loop is best known for its presence in ATP- and GTP-binding proteins, and is also found in a variety of proteins with phosphorylated substrates. Major lineages include:
RecA and rotor ATP synthase / ATPases (α and β subunits).
Nucleic acid-dependent ATPases: helicases, Swi2, and PhoH ()
AAA proteins
STAND NTPases including MJ, PH, AP, and NACHT ATPases
ABC-PilT ATPases
Nucleotide kinases ()
G domain proteins: G-proteins (transducin), myosin.
Walker A motif
Walker A motif, also known as the Walker loop, or P-loop, or phosphate-binding loop, is a motif in proteins that is associated with phosphate binding. The motif has the pattern G-x(4)-GK-[TS], where G, K, T and S denote glycine, lysine, threonine and serine residues respectively, and x denotes any amino acid. It is present in many ATP or GTP utilizing proteins; it is the β phosphate of the nucleotide that is bound. The lysine (K) residue in the Walker A motif, together with the main chain NH atoms, are crucial for nucleotide-binding. It is a glycine-rich loop preceded by a beta strand and followed by an alpha helix; these features are typically part of an α/β domain with four strands sandwiched between two helices on each side. The phosphate groups of the nucleotide are also coordinated to a divalent cation such as a magnesium, calcium, or manganese(II) ion.
Apart from the conserved lysine, a feature of the P-loop used in phosphate binding is a compound LRLR nest comprising the four residues xxGK, as above, whose main chain atoms form a phosphate-sized concavity with the NH groups pointing inwards. The synthetic hexapeptide SGAGKT has been shown |
https://en.wikipedia.org/wiki/Orthopedic%20pathology | Orthopedic pathology, also known as bone pathology is a subspecialty of surgical pathology which deals with the diagnosis and feature of many bone diseases, specifically studying the cause and effects of disorders of the musculoskeletal system. It uses gross and microscopic findings along with the findings of in vivo radiological studies, and occasionally, specimen radiographs to diagnose diseases of the bones.
Causes and effects
Orthopaedic disorders may be congenital and there may be hereditary and environmental factors that can affect the normal functioning of the bones, joints, or muscles. Other causes of bone diseases include severe impacts/injuries and weakness in bones/bone loss.
The effects of bone disorders will vary with disease. The effects can occur physically, mentally and financially as well as impact the individuals quality of life. Orthopaedic disorders can drastically affect an individual's functional ability. Individuals who have had bone diseases can experience complications such as extreme pain, fractures, height loss and the ability to be mobile. They can also be more susceptible to other issues, for example, a urinary tract infection (UTI) or pneumonia. Many of these bone disorders could lead to declines in both mental and physical health. In addition to a physical impact, bone disorders can also give rise to psychological ramifications and reflect negatively on an individual's mindset, body image as well as self-esteem, which may result in the individual feeling helpless and yield fears of falling.
To care for bone diseases and disorders is quite expensive. These costs can include both direct and indirect medical expenses as well as possible job loss or productivity loss for the patient. The chances of death vary enormously between the bone disorders due to the differing degree of severity, however many bone diseases do increase an individual's susceptibility to other complications. These disorders depend on multiple factors such as geneti |
https://en.wikipedia.org/wiki/Polyvinylpolypyrrolidone | Polyvinylpolypyrrolidone (polyvinyl polypyrrolidone, PVPP, crospovidone, crospolividone, or E1202) is a highly cross-linked modification of polyvinylpyrrolidone (PVP).
The cross-linked form of PVP is used as a disintegrant (see also excipients) in pharmaceutical tablets. PVPP is a highly cross-linked version of PVP, making it insoluble in water, though it still absorbs water and swells very rapidly generating a swelling force. This property makes it useful as a disintegrant in tablets.
PVPP can be used as a drug, taken as a tablet or suspension to absorb compounds (so-called endotoxins) that cause diarrhea. (Cf. bone char, charcoal.)
It is also used as a fining to extract impurities (via agglomeration followed by filtration). It is used in winemaking. Using the same principle it is used to remove polyphenols in beer production and thus clear beers with stable foam are produced. One such commercial product is called Polyclar. PVPP forms bonds similar to peptidic bonds in protein (especially, like proline residues) and that is why it can precipitate tannins the same way as proteins do.
PVPP has E number code E1202 and is used as a stabiliser.
See also
Polyethylene glycol-polyvinyl alcohol |
https://en.wikipedia.org/wiki/Herbert%20Gr%C3%B6tzsch | Camillo Herbert Grötzsch (21 May 1902 – 15 May 1993) was a German mathematician. He was born in Döbeln and died in Halle. Grötzsch worked in graph theory. He was the discoverer and eponym of the Grötzsch graph, a triangle-free graph that requires four colors in any graph coloring, and Grötzsch's theorem, the result that every triangle-free planar graph requires at most three colors. A student of Paul Koebe, he made important contributions to the theory of conformal mappings and univalent functions: he was the first to introduce the concept of a quasiconformal mapping.
Publications
Herbert Grötzsch, Über die Verzerrung bei schlichten nicht-konformen Abbildungen und über eine damit zusammenhängende Erweiterung des Picardschen Satzes, Sitzungsberichte sächs. Akad. Wiss., Math.-Phys. Klasse, vol. 80, 1928, pp. 503–507 |
https://en.wikipedia.org/wiki/Timed%20comments | Timed comments are a feature offered by some audio and video players and websites where people can add comments associated with specific times in an audio or video. These comments are then displayed in the player when that time is reached while playing the audio or video.
Timed comments differ from annotations, captions, and subtitles in an important respect: they can be added by viewers, not just video creators, and they include the identity of the person adding the comment.
Examples
SoundCloud, an audio distribution platform and music sharing website: Timed comments can be added at a specific minute and second mark in a soundtrack, and are displayed when the track reaches that minute and second mark. Users can see each others' comments.
Viki, a video streaming website that hosts a number of television shows and movies from Korea, Japan, China, and Taiwan. Viki's timed commenting system is one of its distinguishing features.
Viddler, a video platform used for training videos. |
https://en.wikipedia.org/wiki/Signed%20set | In mathematics, a signed set is a set of elements together with an assignment of a sign (positive or negative) to each element of the set.
Representation
Signed sets may be represented mathematically as an ordered pair of disjoint sets, one set for their positive elements and another for their negative elements. Alternatively, they may be represented as a Boolean function, a function whose domain is the underlying unsigned set (possibly specified explicitly as a separate part of the representation) and whose range is a two-element set representing the signs.
Signed sets may also be called -graded sets.
Application
Signed sets are fundamental to the definition of oriented matroids.
They may also be used to define the faces of a hypercube. If the hypercube consists of all points in Euclidean space of a given dimension whose Cartesian coordinates are in the interval , then a signed subset of the coordinate axes can be used to specify the points whose coordinates within the subset are or (according to the sign in the signed subset) and whose other coordinates may be anywhere in the interval . This subset of points forms a face, whose codimension is the cardinality of the signed subset.
Combinatorics
Enumeration
The number of signed subsets of a given finite set of elements is , a power of three, because there are three choices for each element: it may be absent from the subset, present with positive sign, or present with negative sign. For the same reason, the number of signed subsets of cardinality is
and summing these gives an instance of the binomial theorem,
Intersecting families
An analogue of the Erdős–Ko–Rado theorem on intersecting families of sets holds also for signed sets. The intersection of two signed sets is defined to be the signed set of elements that belong to both and have the same sign in both. According to this theorem, for any a collection of signed subsets of an -element set, all having cardinality and all pairs having a non-empty inte |
https://en.wikipedia.org/wiki/Fractional%20quantum%20Hall%20effect | The fractional quantum Hall effect (FQHE) is a physical phenomenon in which the Hall conductance of 2-dimensional (2D) electrons shows precisely quantized plateaus at fractional values of . It is a property of a collective state in which electrons bind magnetic flux lines to make new quasiparticles, and excitations have a fractional elementary charge and possibly also fractional statistics. The 1998 Nobel Prize in Physics was awarded to Robert Laughlin, Horst Störmer, and Daniel Tsui "for their discovery of a new form of quantum fluid with fractionally charged excitations"
The microscopic origin of the FQHE is a major research topic in condensed matter physics.
Descriptions
The fractional quantum Hall effect (FQHE) is a collective behavior in a 2D system of electrons. In particular magnetic fields, the electron gas condenses into a remarkable liquid state, which is very delicate, requiring high quality material with a low carrier concentration, and extremely low temperatures. As in the integer quantum Hall effect, the Hall resistance undergoes certain quantum Hall transitions to form a series of plateaus. Each particular value of the magnetic field corresponds to a filling factor (the ratio of electrons to magnetic flux quanta)
where p and q are integers with no common factors. Here q turns out to be an odd number with the exception of two filling factors 5/2 and 7/2. The principal series of such fractions are
and
Fractionally charged quasiparticles are neither bosons nor fermions and exhibit anyonic statistics. The fractional quantum Hall effect continues to be influential in theories about topological order. Certain fractional quantum Hall phases appear to have the right properties for building a topological quantum computer.
History and developments
The FQHE was experimentally discovered in 1982 by Daniel Tsui and Horst Störmer, in experiments performed on gallium arsenide heterostructures developed by Arthur Gossard.
There were several major steps in |
https://en.wikipedia.org/wiki/Debrecen%20Award%20for%20Molecular%20Medicine | The Debrecen Award for Molecular Medicine was established in 2003. With the award the Faculty of Medicine of the University of Debrecen, Hungary aims to recognize extraordinary achievements in the field of biomedicine. Nominees are expected to have made great strides in life sciences leading to remarkable progress in our understanding and more efficient treatment of diseases. The prize amount is set at 10,000 Euros. Each year the decision is reached by secret ballot with all professors of the Faculty of Medicine (University of Debrecen) having the right to participate in the voting.
Award winners
2022 Alexander J. Varshavsky
2021 Katalin Karikó
2019 Valina L. Dawson
2018 Sir David Philip Lane
2017 Franz-Ulrich Hartl
2016 Michael N. Hall
2015 Carl June
2014 Sir Stephen O'Rahilly
2013 Donald M. Bers
2012 Shigekazu Nagata
2011 Sir Salvador Moncada
2010 Yosef Yarden
2009 Axel Ullrich
2008 Bruce M. Spiegelman
2007 Alain Fischer
2006 Ralph M. Steinman
2005 Thomas A. Waldmann
2004 Sir Philip Cohen
2003 J. Craig Venter
See also
List of biomedical science awards |
https://en.wikipedia.org/wiki/Key%20Habitat%20Site | A Key Habitat Site is a Canadian Wildlife Service designation for an area that supports at least 1% of the country's population of any migratory bird species, or subspecies, at any time. There may be overlap with areas designated as a migratory bird sanctuary or National Wildlife Area. |
https://en.wikipedia.org/wiki/L%20band%20%28infrared%29 | In infrared astronomy, the L band is an atmospheric transmission window centred on 3.5 micrometres (in the mid-infrared).
Electromagnetic spectrum
Infrared imaging |
https://en.wikipedia.org/wiki/Cross-cultural%20differences%20in%20decision-making | Decision-making is a mental activity which is an integral part of planning and action taking in a variety of contexts and at a vast range of levels, including, but not limited to, budget planning, education planning, policy making, and climbing the career ladder. People all over the world engage in these activities. The underlying cross-cultural differences in decision-making can be a great contributing factor to efficiency in cross-cultural communications, negotiations, and conflict resolution.
Culture in decision-making
Over-generalization in research on decision-making
A considerable amount of literature in cognitive science has been devoted to the investigation of the nature of human decision-making. However, a large portion of it discusses the results obtained from a cultural subject pool, predominantly from a pool of American undergraduate students. Notwithstanding this limitation, the results are usually implicitly or explicitly generalized, which gives rise to the home-field disadvantage: when a particular cultural group is taken as a starting point, it becomes much harder for the researches to notice, or to 'mark', the peculiarities existing within the group. As a result, what is characteristic only of the group under study is taken for granted and ascribed to the general population. This tendency is further aggravated when the researcher belongs to the cultural group that they study. In this case, the researcher and the subjects are exposed to the same physical, social, and situational contexts on the daily basis. Much of every-day functioning is automatic, in other words it is driven by the current features of the environment we are in, that are processed without any conscious awareness. This leads to the building of implicit attitude, values, and beliefs, which are hard to spot. They become apparent when individuals or decision-making models from different cultural backgrounds as different culture backgrounds tend to form different mind processing in |
https://en.wikipedia.org/wiki/F%C3%A9d%C3%A9ration%20nationale%20des%20boulangers%20et%20p%C3%A2tissiers%20du%20Burkina | Fédération nationale des boulangers et pâtissiers du Burkina (FNBPB) is a trade union of bakery workers in Burkina Faso. The union was founded on April 4, 1960. FNBPB is affiliated to Confédération générale du travail du Burkina (CGT-B). Djigimdé Tiga is the president of FNBPB.
FNBPB is a member of the International Union of Food, Agricultural, Hotel, Restaurant, Catering, Tobacco and Allied Workers' Association. |
https://en.wikipedia.org/wiki/Elli | In Norse mythology (a subset of Germanic mythology), Elli (Old Norse: , "old age") is a personification of old age who, in the Prose Edda book Gylfaginning, defeats Thor in a wrestling match.
Gylfaginning
In Gylfaginning, Thor and his companions Loki and Þjálfi are in the hall of the jötunn Útgarða-Loki where they meet difficult challenges testing their strength and skill. Thor has just been humiliated in a drinking challenge and wants to get even.
Then said Thor: 'Little as ye call me, let any one come up now and wrestle with me; now I am angry.' Then Útgarda-Loki answered, looking about him on the benches, and spake: 'I see no such man here within, who would not hold it a disgrace to wrestle with thee;' and yet he said: 'Let us see first; let the old woman my nurse be called hither, Elli, and let Thor wrestle with her if he will. She has thrown such men as have seemed to me no less strong than Thor.' Straightway there came into the hall an old woman, stricken in years. Then Útgarda-Loki said that she should grapple with Ása-Thor. There is no need to make a long matter of it: that struggle went in such wise that the harder Thor strove in gripping, the faster she stood; then the old woman attempted a hold, and then Thor became totty on his feet, and their tuggings were very hard. Yet it was not long before Thor fell to his knee, on one foot. Then Útgarda-Loki went up and bade them cease the wrestling, saying that Thor should not need to challenge more men of his body-guard to wrestling.
Later, when Thor and his company are safely out of Útgarða-Loki's hall the jötunn explains that Thor's opponent was much more formidable than she appeared to be and that Thor's prowess was, in fact, astonishing.
It was also a great marvel concerning the wrestling-match, when thou didst withstand so long; and didst not fall more than on one knee, wrestling with Elli; since none such has ever been and none shall be, if he become so old as to abide "Old Age," that she shall not cause |
https://en.wikipedia.org/wiki/Okazaki%20fragments | Okazaki fragments are short sequences of DNA nucleotides (approximately 150 to 200 base pairs long in eukaryotes) which are synthesized discontinuously and later linked together by the enzyme DNA ligase to create the lagging strand during DNA replication. They were discovered in the 1960s by the Japanese molecular biologists Reiji and Tsuneko Okazaki, along with the help of some of their colleagues.
During DNA replication, the double helix is unwound and the complementary strands are separated by the enzyme DNA helicase, creating what is known as the DNA replication fork. Following this fork, DNA primase and DNA polymerase begin to act in order to create a new complementary strand. Because these enzymes can only work in the 5’ to 3’ direction, the two unwound template strands are replicated in different ways. One strand, the leading strand, undergoes a continuous replication process since its template strand has 3’ to 5’ directionality, allowing the polymerase assembling the leading strand to follow the replication fork without interruption. The lagging strand, however, cannot be created in a continuous fashion because its template strand has 5’ to 3’ directionality, which means the polymerase must work backwards from the replication fork. This causes periodic breaks in the process of creating the lagging strand. The primase and polymerase move in the opposite direction of the fork, so the enzymes must repeatedly stop and start again while the DNA helicase breaks the strands apart. Once the fragments are made, DNA ligase connects them into a single, continuous strand. The entire replication process is considered "semi-discontinuous" since one of the new strands is formed continuously and the other is not.
During the 1960s, Reiji and Tsuneko Okazaki conducted experiments involving DNA replication in the bacterium Escherichia coli. Before this time, it was commonly thought that replication was a continuous process for both strands, but the discoveries involving E. |
https://en.wikipedia.org/wiki/Process%20variation%20%28semiconductor%29 | Process variation is the naturally occurring variation in the attributes of transistors (length, widths, oxide thickness) when integrated circuits are fabricated. The amount of process variation becomes particularly pronounced at smaller process nodes (<65 nm) as the variation becomes a larger percentage of the full length or width of the device and as feature sizes approach the fundamental dimensions such as the size of atoms and the wavelength of usable light for patterning lithography masks.
Process variation causes measurable and predictable variance in the output performance of all circuits but particularly analog circuits due to mismatch. If the variance causes the measured or simulated performance of a particular output metric (bandwidth, gain, rise time, etc.) to fall below or rise above the specification for the particular circuit or device, it reduces the overall yield for that set of devices.
History
The first mention of variation in semiconductors was by William Shockley, the co-inventor of the transistor, in his 1961 analysis of junction breakdown.
An analysis of systematic variation was performed by Schemmert and Zimmer in 1974 with their paper on threshold-voltage sensitivity. This research looked into the effect that the oxide thickness and implantation energy had on the threshold voltage of MOS devices.
sources of variations
1) gate oxide thickness
2) random dopant fluctuations
3) Device Geometry, Lithography in nanometer region
Characterization
Semiconductor foundries run analyses on the variability of attributes of transistors (length, width, oxide thickness, etc.) for each new process node. These measurements are recorded and provided to customers such as fabless semiconductor companies. This set of files are generally referred to as "model files" in the industry and are used by EDA tools for simulation of designs.
FEOL
Typically process models (example HSPICE ) include process corners based on Front End Of Line conditions. These often a |
https://en.wikipedia.org/wiki/Immunotoxicology | Immunotoxicology (sometimes abbreviated as ITOX) is the study of the toxicity of foreign substances called xenobiotics and their effects on the immune system. Some toxic agents that are known to alter the immune system include: industrial chemicals, heavy metals, agrochemicals, pharmaceuticals, drugs, ultraviolet radiation, air pollutants and some biological materials. The effects of these immunotoxic substances have been shown to alter both the innate and adaptive parts of the immune system. Consequences of xenobiotics affect the organ initially in contact (often the lungs or skin). Some commonly seen problems that arise as a result of contact with immunotoxic substances are: immunosuppression, hypersensitivity, and autoimmunity. The toxin-induced immune dysfunction may also increase susceptibility to cancer.
The study of immunotoxicology began in the 1970s. However, the idea that some substances have a negative effect on the immune system was not a novel concept as people have observed immune system alterations as a result of contact toxins since ancient Egypt. Immunotoxicology has become increasingly important when considering the safety and effectiveness of commercially sold products. In recent years, guidelines and laws have been created in the effort to regulate and minimize the use of immunotoxic substances in the production of agricultural products, drugs, and consumer products. One example of these regulations are FDA guidelines mandate that all drugs must be tested for toxicity to avoid negative interactions with the immune system, and in-depth investigations are required whenever a drug shows signs of affecting the immune system. Scientists use both in vivo and in vitro techniques when determining the immunotoxic effects of a substance.
Immunotoxic agents can damage the immune system by destroying immune cells and changing signaling pathways. This has wide-reaching consequences in both the innate and adaptive immune systems. Changes in the adaptive immu |
https://en.wikipedia.org/wiki/Ultrasonic%20algae%20control | Ultrasonic algae control is a commercial technology that has been claimed to control the blooming of cyanobacteria, algae, and biofouling in lakes, and reservoirs, by using pulsed ultrasound. The duration of such treatment is supposed to take up to several months, depending on the water volume and algae species. Despite the experimental demonstration of certain bioeffects in small samples under controlled laboratory and sonication conditions, there is no scientific foundation for outdoors ultrasonic algae control.
Academic studies
It has been speculated that ultrasound produced at the resonance frequencies of cells or their membranes may cause them to rupture.
The center frequencies of the ultrasound pulses used in academic studies lie between 20 kHz and 2.5 MHz. The acoustic powers, pressures, and intensities applied vary from low, not affecting humans,
to high, unsafe for swimmers.
According to research at the University of Hull, ultrasound-assisted gas release from blue-green algae cells may take place from nitrogen-containing cells, but only under very specific short-distance conditions, which are not representative for intended outdoors applications. In addition, a study by Wageningen University on several algae species concluded that most claims on outdoors ultrasonic algae control are unsubstantiated.
See also
Ultrasonic antifouling |
https://en.wikipedia.org/wiki/SuperPrime | SuperPrime is a computer program used for calculating the primality of a large set of positive natural numbers. Because of its multi-threaded nature and dynamic load scheduling, it scales excellently when using more than one thread (execution core). It is commonly used as an overclocking benchmark to test the speed and stability of a system.
Background information
In August 1995, the calculation of Pi up to 4,294,960,000 decimal digits was achieved by using a supercomputer at the University of Tokyo. The program used to achieve this was ported to personal computers, for operating systems such as Windows NT and Windows 95 and called Super-PI. SuperPrime is another take on this procedure, substituting raw floating-point calculations for the value of Pi with more complex instructions to calculate the primality of a set of natural numbers.
Landmarks
On September 29, 2006, a milestone was broken when bachus_anonym of www.xtremesystems.org broke the 30 seconds barrier using a highly overclocked Core 2 Duo machine
See also
Erodov.com, the 'home forum' for the SuperPrime benchmark. |
https://en.wikipedia.org/wiki/Accelerated%20Mobile%20Pages | AMP (originally an acronym for Accelerated Mobile Pages) is an open source HTML framework developed by the AMP Open Source Project. It was originally created by Google as a competitor to Facebook Instant Articles and Apple News. AMP is optimized for mobile web browsing and intended to help webpages load faster. AMP pages may be cached by a CDN, such as Microsoft Bing or Cloudflare's AMP caches, which allows pages to be served more quickly.
AMP was first announced on October 7, 2015. After a technical preview period, AMP pages began appearing in Google mobile search results in February 2016. AMP has been criticized for potentially giving further control over the web to Google and other concerns. The AMP Project announced it would move to an open governance model on September 18, 2018 and is part of the OpenJS Foundation as of October 10, 2019.
History
Announcement and launch
The AMP Project was announced by Google on October 7, 2015, following discussions with its partners in the Digital News Initiative (DNI), and other news publishers and technology companies around the world, about improving the performance of the mobile web. More than 30 news publishers and several technology companies (including Twitter, Pinterest, LinkedIn and WordPress) were initially announced as collaborators in the AMP Project.
AMP pages first appeared to web users in February 2016, when Google began to show the AMP versions of webpages in mobile search results. Initially links to AMP pages were restricted to a "Top Stories" section of Google's mobile search results; by September 2016 Google started linking to AMP content in the main mobile search results area. At the time, Google search distinguished AMP links with an icon.
According to one of the co-founders of the AMP Project, Malte Ubl, AMP was originally called PCU, which stood for Portable Content Unit.
Growth and expansion
In September 2016, Microsoft announced support for AMP in the Bing apps for iOS and Android.
In February |
https://en.wikipedia.org/wiki/Continuous-time%20quantum%20walk | A continuous-time quantum walk (CTQW) is a quantum walk on a given (simple) graph that is dictated by a time-varying unitary matrix that relies on the Hamiltonian of the quantum system and the adjacency matrix. The concept of a CTQW is believed to have been first considered for quantum computation by Edward Farhi and Sam Gutmann; since many classical algorithms are based on (classical) random walks, the concept of CTQWs were originally considered to see if there could be quantum analogues of these algorithms with e.g. better time-complexity than their classical counterparts. In recent times, problems such as deciding what graphs admit properties such as perfect state transfer with respect to their CTQWs have been of particular interest.
Definitions
Suppose that is a graph on vertices, and that .
Continuous-time quantum walks
The continuous-time quantum walk on at time is defined as:letting denote the adjacency matrix of .
It is also possible to similarly define a continuous-time quantum walk on relative to its Laplacian matrix; although, unless stated otherwise, a CTQW on a graph will mean a CTQW relative to its adjacency matrix for the remainder of this article.
Mixing matrices
The mixing matrix of at time is defined as .
Mixing matrices are symmetric doubly-stochastic matrices obtained from CTQWs on graphs: gives the probability of transitioning to at time for any vertices and v on .
Periodic vertices
A vertex on is said to periodic at time if .
Perfect state transfer
Distinct vertices and on are said to admit perfect state transfer at time if .
If a pair of vertices on admit perfect state transfer at time t, then itself is said to admit perfect state transfer (at time t).
A set of pairs of distinct vertices on is said to admit perfect state transfer (at time ) if each pair of vertices in admits perfect state transfer at time .
A set of vertices on is said to admit perfect state transfer (at time ) if for all there is a |
https://en.wikipedia.org/wiki/Automate%20This | Automate This: How Algorithms Came to Rule Our World is a book written by Christopher Steiner and published by Penguin Group. Steiner begins his study of algorithms on Wall Street in the 1980s but also provides examples from other industries. For example, he explains the history of Pandora Radio and the use of algorithms in music identification. He expresses concern that such use of algorithms may lead to the homogenization of music over time. Steiner also discusses the algorithms that eLoyalty (now owned by Mattersight Corporation following divestiture of the technology) was created by dissecting 2 million speech patterns and can now identify a caller's personality style and direct the caller with a compatible customer support representative.
Steiner's book shares both the warning and the opportunity that algorithms bring to just about every industry in the world, and the pros and cons of the societal impact of automation (e.g. impact on employment).
See also
Technological unemployment
Race Against The Machine: How the Digital Revolution is Accelerating Innovation, Driving Productivity, and Irreversibly Transforming Employment and the Economy |
https://en.wikipedia.org/wiki/Hepatoduodenal%20ligament | The hepatoduodenal ligament is the portion of the lesser omentum extending between the porta hepatis of the liver and the superior part of the duodenum.
Running inside it are the following structures collectively known as the portal triad:
hepatic artery proper
portal vein
common bile duct
Manual compression of the hepatoduodenal ligament during surgery is known as the Pringle manoeuvre.
The cystoduodenal ligament is also found in the lesser omentum and is distinct from both the hepatoduodenal and hepatogastric ligaments. The cystoduodenal ligament is an abnormal peritoneal fold that attaches the duodenum to the gallbladder, representing a rare variation in the anatomy of the lesser sac and its foramen.
Another variation sometimes present at the duodenal termination of the hepatoduodenal ligament is the duodenorenal ligament which passes to the front of the right kidney. |
https://en.wikipedia.org/wiki/Cryptogram | A cryptogram is a type of puzzle that consists of a short piece of encrypted text. Generally the cipher used to encrypt the text is simple enough that the cryptogram can be solved by hand. Substitution ciphers where each letter is replaced by a different letter or number are frequently used. To solve the puzzle, one must recover the original lettering. Though once used in more serious applications, they are now mainly printed for entertainment in newspapers and magazines.
Other types of classical ciphers are sometimes used to create cryptograms. An example is the book cipher where a book or article is used to encrypt a message.
History of cryptograms
The ciphers used in cryptograms were not originally created for entertainment purposes, but for real encryption of military or personal secrets.
The first use of the cryptogram for entertainment purposes occurred during the Middle Ages by monks who had spare time for intellectual games. A manuscript found at Bamberg states that Irish visitors to the court of Merfyn Frych ap Gwriad (died 844), king of Gwynedd in Wales were given a cryptogram which could only be solved by transposing the letters from Latin into Greek. Around the thirteenth century, the English monk Roger Bacon wrote a book in which he listed seven cipher methods, and stated that "a man is crazy who writes a secret in any other way than one which will conceal it from the vulgar." In the 19th century Edgar Allan Poe helped to popularize cryptograms with many newspaper and magazine articles.
Well-known examples of cryptograms in contemporary culture are the syndicated newspaper puzzles Cryptoquip and Cryptoquote, from King Features. And Celebrity Cipher, distributed by Andrew McMeel, is another captivating cipher game in contemporary culture, offering a stimulating challenge by decrypting quotes from famous personalities.
In a public challenge, writer J.M. Appel announced on September 28, 2014, that the table of contents page of his short story collecti |
https://en.wikipedia.org/wiki/Email%20migration | Email migration is a process in which an email or multiple email messages are migrated from one email client to another email client. An equivalent term is Mailbox Migration, in which case records such as e-mails, appointments, contacts or tasks may also be migrated. In general, email migration is required when a user is switching from its current email client to a new one. Usually, email clients don't support similar file formats for saving mailbox data.
Scenarios
Mailboxes may be migrated for different reasons. For example, mailboxes may need to be migrated because a company wants to use a new email service provider. Or mailboxes may need to be migrated following a company acquisition or merger. In most cases, a simple one-time migration approach may be employed. However, more advanced scenarios exist, including:
Consolidation: email migration is performed to consolidate multiple accounts into one, for example following an employee's departure.
Backup: email migration is performed to back up or preserve data, for example, to ensure legal compliance.
Coexistence: email migration is performed for evaluation purposes, for example during a migration pilot.
Upgrade: email migration is performed to facilitate an upgrade, for example when deploying a new version of an email system.
Procedure
Various technical procedures are normally used to achieve email migration:
Email forwarding: this allows a mailbox to forward received content to a designated email address.
MX record modification: this allows a mail server to process emails on behalf of a designated SMTP domain.
Content conversion: this allows content to be converted, for example from TNEF to MIME format.
Property mapping: this allows properties to be mapped, for example from Gmail to Exchange contacts.
Copy Email: Make a copy of an email from a source mailbox to a destination mailbox
Features
Email migration solutions may implement different features which determine their suitability for different m |
https://en.wikipedia.org/wiki/Opioid%20peptide | Opioid peptides or opiate peptides are peptides that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Such peptides may be produced by the body itself, for example endorphins. The effects of these peptides vary, but they all resemble those of opiates. Brain opioid peptide systems are known to play an important role in motivation, emotion, attachment behaviour, the response to stress and pain, control of food intake, and the rewarding effects of alcohol and nicotine.
Opioid-like peptides may also be absorbed from partially digested food (casomorphins, exorphins, and rubiscolins). Opioid peptides from food typically have lengths between 4–8 amino acids. Endogenous opioids are generally much longer.
Opioid peptides are released by post-translational proteolytic cleavage of precursor proteins. The precursors consist of the following components: a signal sequence that precedes a conserved region of about 50 residues; a variable-length region; and the sequence of the neuropeptides themselves. Sequence analysis reveals that the conserved N-terminal region of the precursors contains 6 cysteines, which are probably involved in disulfide bond formation. It is speculated that this region might be important for neuropeptide processing.
Endogenous
The human genome contains several homologous genes that are known to code for endogenous opioid peptides.
The nucleotide sequence of the human gene for proopiomelanocortin (POMC) was characterized in 1980. The POMC gene codes for endogenous opioids such as β-endorphin and γ-endorphin.
The human gene for the enkephalins was isolated and its sequence described in 1982.
The human gene for dynorphins (originally called the "Enkephalin B" gene because of sequence similarity to the enkephalin gene) was isolated and its sequence described in 1983.
The PNOC gene encoding prepronociceptin, which is cleaved into nociceptin and potentially two additional neuropeptides.
Adrenorphin, amidorphin, and |
https://en.wikipedia.org/wiki/Shared-cost%20service | Shared-cost service is a type of telephone call billing where the charge for calling a particular telephone number is partially, but not entirely, paid for by the recipient.
Shared cost numbers normally enable non-geographical or long-distance calls that are priced to the caller as if they were local while the difference is paid by the called party.
See also
Universal International Shared Cost Number, an international shared-cost numbering scheme
External links
ITU ISCS page
Telephone numbers |
https://en.wikipedia.org/wiki/Tide-Predicting%20Machine%20No.%202 | Tide-Predicting Machine No. 2, also known as Old Brass Brains, was a special-purpose mechanical computer that uses gears, pulleys, chains, and other mechanical components to compute the height and time of high and low tides for specific locations. The machine can perform tide calculations much faster than a person could do with pencil and paper. The U.S. Coast and Geodetic Survey put the machine into operation in 1910. It was used until 1965, when it was replaced by an electronic computer.
Early U.S. tide-prediction efforts
Tides are the rise and fall of sea levels caused by the combined effects of gravitational forces exerted by the Moon, Sun, and rotation of the Earth. In 1867 the United States Coast Survey started printing annual tide tables to support safe and effective maritime, coastal, and defense activities. Before long, these tables showed the times and heights of high and low tides to the nearest minute and tenth of a foot, respectively. Tables were printed for a year at a time and distributed prior to the start of the year.
The prediction of tides is very challenging as it depends on multiple factors–including the alignment of the Sun and Moon, the shape of the coastline, and near-shore bathymetry. Tide theories attempt to account for these factors but lead to complex calculations. Originally, calculations were performed by hand, which was very labor-intensive and error-prone. The burden became even larger when the United States Coast and Geodetic Survey (USCGS, the successor to the Coast Survey) started using the more accurate harmonic method for predictions of tides in 1884.
To significantly reduce the work required to predict tides, in 1881 William Ferrel of the USCGS designed a tide-predicting machine. Fauth & Co. Instrument Makers built Tide-Predicting Machine No. 1 and delivered it in 1882. The Survey started using the machine routinely in 1883.
History and mechanism
In 1895 the USCGS grew concerned because Tide-Predicting Machine No. 1 had de |
https://en.wikipedia.org/wiki/Elabela | ELABELA (ELA, Apela, Toddler) is a hormonal peptide that in humans is encoded by the APELA gene. Elabela is one of two endogenous ligands for the G-protein-coupled APLNR receptor.
Ela is secreted by certain cell types including human embryonic stem cells. It is widely expressed in various developing organs such as the blastocyst, placenta, heart, kidney, endothelium, and is circulating in human plasma.
Discovery
Elabela is a micropeptide that was identified in 2013 by Professor Bruno Reversade's team.
Biosynthesis
Elabela gene encodes a pre-proprotein of 54 amino acids, with a signal peptide in the N-terminal region. After translocation into the endoplasmic reticulum and cleavage of the signal peptide, the proprotein of 32 amino acids may generate several active fragments.
Physiological functions
The sites of APLNR receptor expression are linked to the different functions played by Elabela in the organism. Despite that, Elabela is capable of signaling independently of APLNR in human embryonic stem cells and certain cancer cell lines including OVISE.
Embryonic pluripotency
The Elabela protein is synthesized, processed and secreted by undifferentiated human embryonic stem cells but not mouse embryonic stem cells. In humans it is under the direct regulation of POU5F1 (a.k.a. OCT4) and NANOG.
Through autocrine and paracrine signalling, endogenous Elabela entrains the PI3K/AKT/mTOR pathway to maintain pluripotency and self-renewal.
Vascular
Elabela is expressed by midline tissues (such as the notochord in zebrafish and neural tube in mammals) during organogenesis.
There it serves as a chemoattractant to angioblasts expressing APLNR at their cell surface. This participates in the formation of the first and secondary vessels of the vascular system.
Cardiac
The ELABELA -APLNR signaling axis is required for formation of the coronary vessels of the heart in mice through the sinus venosus progenitors.
Pre-eclampsia
ELA is a secreted into the bloodstream by |
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