source stringlengths 31 227 | text stringlengths 9 2k |
|---|---|
https://en.wikipedia.org/wiki/Earth%27s%20field%20NMR | Nuclear magnetic resonance (NMR) in the geomagnetic field is conventionally referred to as Earth's field NMR (EFNMR). EFNMR is a special case of low field NMR.
When a sample is placed in a constant magnetic field and stimulated (perturbed) by a time-varying (e.g., pulsed or alternating) magnetic field, NMR active nuclei resonate at characteristic frequencies. Examples of such NMR active nuclei are the isotopes carbon-13 and hydrogen-1 (which in NMR is conventionally known as proton NMR). The resonant frequency of each isotope is directly proportional to the strength of the applied magnetic field, and the magnetogyric or gyromagnetic ratio of that isotope. The signal strength is proportional both to the stimulating magnetic field and the number of nuclei of that isotope in the sample. Thus in the 21 tesla magnetic field that may be found in high resolution laboratory NMR spectrometers, protons resonate at 900 MHz. However, in the Earth's magnetic field the same nuclei resonate at audio frequencies of around 2 kHz and generate very weak signals.
The location of a nucleus within a complex molecule affects the 'chemical environment' (i.e. the rotating magnetic fields generated by the other nuclei) experienced by the nucleus. Thus different hydrocarbon molecules containing NMR active nuclei in different positions within the molecules produce slightly different patterns of resonant frequencies.
EFNMR signals can be affected by both magnetically noisy laboratory environments and natural variations in the Earth's field, which originally compromised its usefulness. However this disadvantage has been overcome by the introduction of electronic equipment which compensates changes in ambient magnetic fields.
Whereas chemical shifts are important in NMR, they are insignificant in the Earth's field. The absence of chemical shifts causes features such as spin-spin multiplets (that are separated by high fields) to be superimposed in EFNMR. Instead, EFNMR spectra are dominated by |
https://en.wikipedia.org/wiki/Mass%20flux | In physics and engineering, mass flux is the rate of mass flow. Its SI units are kg m−2 s−1. The common symbols are j, J, q, Q, φ, or Φ (Greek lower or capital Phi), sometimes with subscript m to indicate mass is the flowing quantity. Mass flux can also refer to an alternate form of flux in Fick's law that includes the molecular mass, or in Darcy's law that includes the mass density.
Sometimes the defining equation for mass flux in this article is used interchangeably with the defining equation in mass flow rate. For example, Fluid Mechanics, Schaum's et al uses the definition of mass flux as the equation in the mass flow rate article.
Definition
Mathematically, mass flux is defined as the limit
where
is the mass current (flow of mass per unit time ) and is the area through which the mass flows.
For mass flux as a vector , the surface integral of it over a surface S, followed by an integral over the time duration to , gives the total amount of mass flowing through the surface in that time ():
The area required to calculate the flux is real or imaginary, flat or curved, either as a cross-sectional area or a surface.
For example, for substances passing through a filter or a membrane, the real surface is the (generally curved) surface area of the filter, macroscopically - ignoring the area spanned by the holes in the filter/membrane. The spaces would be cross-sectional areas. For liquids passing through a pipe, the area is the cross-section of the pipe, at the section considered.
The vector area is a combination of the magnitude of the area through which the mass passes through, A, and a unit vector normal to the area, . The relation is .
If the mass flux passes through the area at an angle θ to the area normal , then
where is the dot product of the unit vectors. That is, the component of mass flux passing through the surface (i.e. normal to it) is . While the component of mass flux passing tangential to the area is given by , there is no mass flux act |
https://en.wikipedia.org/wiki/Neuregulin%201 | Neuregulin 1, or NRG1, is a gene of the epidermal growth factor family that in humans is encoded by the NRG1 gene. NRG1 is one of four proteins in the neuregulin family that act on the EGFR family of receptors. Neuregulin 1 is produced in numerous isoforms by alternative splicing, which allows it to perform a wide variety of functions. It is essential for the normal development of the nervous system and the heart.
Structure
Neuregulin 1 (NRG1) was originally identified as a 44-kD glycoprotein that interacts with the NEU/ERBB2 receptor tyrosine kinase to increase its phosphorylation on tyrosine residues. It is known that an extraordinary variety of different isoforms are produced from the NRG1 gene by alternative splicing. These isoforms include heregulins (HRGs), glial growth factors (GGFs) and sensory and motor neuron-derived factor (SMDF). They are tissue-specific and differ significantly in their structure. The HRG isoforms all contain immunoglobulin (Ig) and epidermal growth factor-like (EGF-like) domains. GGF and GGF2 isoforms contain a kringle-like sequence plus Ig and EGF-like domains; and the SMDF isoform shares only the EGF-like domain with other isoforms. The receptors for all NRG1 isoforms are the ERBB family of tyrosine kinase transmembrane receptors. Through their displayed interaction with ERBB receptors, NRG1 isoforms induce the growth and differentiation of epithelial, neuronal, glial, and other types of cells.
Function
Synaptic plasticity
Neuregulin 1 is thought to play a role in synaptic plasticity. It has been shown that a loss of Neuregulin 1 within cortical projection neurons results in increased inhibitory connections and reduced synaptic plasticity. Similarly, overexpression of Neuregulin 1 results in disrupted excitatory-inhibitory connections, reduced synaptic plasticity, and abnormal dendritic spine growth. Mutations in human L1 cell adhesion molecules are reported to cause a number of neuronal disorders. In addition, recent researc |
https://en.wikipedia.org/wiki/Equable%20shape | A two-dimensional equable shape (or perfect shape) is one whose area is numerically equal to its perimeter. For example, a right angled triangle with sides 5, 12 and 13 has area and perimeter both have a unitless numerical value of 30.
Scaling and units
An area cannot be equal to a length except relative to a particular unit of measurement. For example, if shape has an area of 5 square yards and a perimeter of 5 yards, then it has an area of and a perimeter of 15 feet (since 3 feet = 1 yard and hence 9 square feet = 1 square yard). Moreover, contrary to what the name implies, changing the size while leaving the shape intact changes an "equable shape" into a non-equable shape. However its common use as GCSE coursework has led to its being an accepted concept. For any shape, there is a similar equable shape: if a shape S has perimeter p and area A, then scaling S by a factor of p/A leads to an equable shape. Alternatively, one may find equable shapes by setting up and solving an equation in which the area equals the perimeter. In the case of the square, for instance, this equation is
Solving this yields that x = 4, so a 4 × 4 square is equable.
Tangential polygons
A tangential polygon is a polygon in which the sides are all tangent to a common circle. Every tangential polygon may be triangulated by drawing edges from the circle's center to the polygon's vertices, forming a collection of triangles that all have height equal to the circle's radius; it follows from this decomposition that the total area of a tangential polygon equals half the perimeter times the radius. Thus, a tangential polygon is equable if and only if its inradius is two. All triangles are tangential, so in particular the equable triangles are exactly the triangles with inradius two.
Integer dimensions
Combining restrictions that a shape be equable and that its dimensions be integers is significantly more restrictive than either restriction on its own. For instance, there are infinitely many Pyt |
https://en.wikipedia.org/wiki/Fragmentalism | Fragmentalism is a view that holds that the world consists of individual and independent objects. The term contends that the world is indeed composed of separable parts, and that it is chiefly knowable through the study of these component parts, rather than through wholes. It therefore stands opposed to holistic interpretations of phenomena.
"The Fragmentalists carved the universe up into smaller and smaller pieces until they reached such a fine level of subdivision that they could no longer observe the pieces directly." (Stewart & Cohen, p.198) "As the tale of the Fragmentalists demonstrates, reductionist science usually looks for a mathematical equation, formula, or process that describes general features of the universe." (Stewart & Cohen, p.200)
Fragmentalism has also been defined as the notion that knowledge is a growing collection of substantiated facts or "nuggets of truth." Anti-realists use the term fragmentalism in arguments that the world does not exist of separable entities, instead consisting of wholes. For example, advocates of this position declare that: The linear deterministic approach to nature and technology promoted a fragmented perception of reality, and a loss of the ability to foresee, to adequately evaluate, in all their complexity, global crises in ecology, civilization and education.
This term is usually applied to reductionist modes of thought, frequently with the related pejorative term of scientism. This usage is popular amongst some ecological activists: There is a need now to move away from scientism and the ideology of cause-and-effect determinism toward a radical empiricism, such as William James proposed, as an epistemology of science. These perspectives are not new and in the early twentieth century, William James noted that rationalist science emphasized what he termed fragmentation and disconnection.
Such anti-realist rhetoric also underpins many criticisms of the scientific method: The scientific method only acknowledges mon |
https://en.wikipedia.org/wiki/Syslog-ng | syslog-ng is a free and open-source implementation of the syslog protocol for Unix and Unix-like systems. It extends the original syslogd model with content-based filtering, rich filtering capabilities, flexible configuration options and adds important features to syslog, like using TCP for transport. As of today, syslog-ng is developed by Balabit IT Security Ltd. It has three editions with a common codebase. The first is called syslog-ng Open Source Edition (OSE) with the license LGPL. The second is called Premium Edition (PE) and has additional plugins (modules) under a proprietary license. The third is called Storebox (SSB), which comes as an appliance with a Web-based UI as well as additional features including ultra-fast-text search, unified search, content-based alerting and a premier tier support.
In January 2018, syslog-ng, as part of Balabit, was acquired by One Identity under the Quest Software umbrella. The syslog-ng team remains an independent business within the One Identity organization and continues under the syslog-ng brand.
Protocol
syslog-ng uses the standard BSD syslog protocol, specified in RFC 3164. As the text of RFC 3164 is an informational description and not a standard, some incompatible extensions of it emerged. Since version 3.0 syslog-ng also supports the syslog protocol specified in RFC 5424. syslog-ng interoperates with a variety of devices, and the format of relayed messages can be customized.
Extensions to the original syslog-ng protocol include:
ISO 8601 timestamps with millisecond granularity and time zone information
The addition of the name of relays in additional host fields, to make it possible to track the path of a given message
Reliable transport using TCP
TLS encryption (Since 3.0.1 in OSE )
History
The syslog-ng project began in 1998, when Balázs Scheidler, the primary author of syslog-ng, ported the existing syslog code to Linux. The 1.0.x branch of syslog-ng was still based on the syslog sources and are available |
https://en.wikipedia.org/wiki/Dimethylglycine | Dimethylglycine (DMG) is a derivative of the amino acid glycine with the structural formula (CH3)2NCH2COOH. It can be found in beans and liver, and has a sweet taste. It can be formed from trimethylglycine upon the loss of one of its methyl groups. It is also a byproduct of the metabolism of choline.
When DMG was first discovered, it was referred to as Vitamin B16, but, unlike true B vitamins, deficiency of DMG in the diet does not lead to any ill-effects and it is synthesized by the human body in the citric acid cycle meaning it does not meet the definition of a vitamin.
Uses
Dimethylglycine has been suggested for use as an athletic performance enhancer, immunostimulant, and a treatment for autism, epilepsy, or mitochondrial disease. There is no evidence that dimethylglycine is effective for treating mitochondrial disease. Published studies on the subject have shown little to no difference between DMG treatment and placebo in autism spectrum disorders.
Biological activity
Dimethylglycine has been found to act as an agonist of the glycine site of the NMDA receptor.
Preparation
This compound is commercially available as the free form amino acid, and as the hydrochloride salt []. DMG may be prepared by the alkylation of glycine via the Eschweiler–Clarke reaction. In this reaction, glycine is treated with aqueous formaldehyde in formic acid that serves as both solvent and reductant. Hydrochloric acid is added thereafter to give the hydrochloride salt. The free amino acid may have been obtained by neutralization of the acid salt, which has been performed with silver oxide.
H2NCH2COOH + 2 CH2O + 2 HCOOH → (CH3)2NCH2COOH + 2 CO2 + 2 H2O
See also
Monomethylglycine |
https://en.wikipedia.org/wiki/Adenosylmethionine%20decarboxylase | The enzyme adenosylmethionine decarboxylase () catalyzes the conversion of S-adenosyl methionine to S-adenosylmethioninamine.
Polyamines such as spermidine and spermine are essential for cellular growth under most conditions, being implicated in many cellular processes including DNA, RNA and protein synthesis. S-adenosylmethionine decarboxylase (AdoMetDC) plays an essential regulatory role in the polyamine biosynthetic pathway by generating the n-propylamine residue required for the synthesis of spermidine and spermine from putrescein. Unlike many amino acid decarboxylases AdoMetDC uses a covalently bound pyruvate residue as a cofactor rather than the more common pyridoxal 5'-phosphate. These proteins can be divided into two main groups which show little sequence similarity either to each other, or to other pyruvoyl-dependent amino acid decarboxylases: class I enzymes found in bacteria and archaea, and class II enzymes found in eukaryotes. In both groups the active enzyme is generated by the post-translational autocatalytic cleavage of a precursor protein. This cleavage generates the pyruvate precursor from an internal serine residue and results in the formation of two non-identical subunits termed alpha and beta which form the active enzyme. |
https://en.wikipedia.org/wiki/Indohyus | Indohyus is an extinct genus of digitigrade even-toed ungulates known from Eocene fossils in Asia. This small chevrotain-like animal found in the Himalayas is one of the earliest known non-cetacean ancestors of whales.
Discovery
The fossils were discovered among rocks that had been collected in 1971 in Kashmir by the Indian geologist A. Ranga Rao who found a few teeth and parts of a jawbone, but when he died many rocks had yet to be broken open. Ranga Rao's widow gave the rocks to Hans Thewissen, who was working on them. When his technician accidentally broke one of the skulls they had found, Thewissen recognised the ear structure of the auditory bulla, formed from the ectotympanic bone in a shape which is highly distinctive, found only in the skulls of cetaceans both living and extinct, including Pakicetus.
Paleobiology
About the size of a raccoon or domestic cat, this omnivorous pig-like creature shared some of the traits of whales, and showed signs of adaptations to aquatic life. Their bones were similar to the bones of modern creatures such as the hippopotamus, and helped reduce buoyancy so that they could stay underwater. This suggests a survival strategy similar to that of the African mousedeer or water chevrotain which, when threatened by a bird of prey, dives into water and hides beneath the surface for up to four minutes.
From isotopes and the structure of the bones in the fossils Indohyus had heavy bones. Heavy bones help reduce the buoyancy of living aquatic mammals so that they do not float up to the surface of the water.
Classification
Raoellids may be the "missing link" sister group to whales (Cetacea). All other Artiodactyla are "cousins" of these two groups. 18O values and osteosclerotic bones indicate that the raccoon-like or chevrotain-like Indohyus was habitually aquatic, but 13C values suggest that it rarely fed in the water. The authors suggest this documents an intermediate step in the transition back to water completed by the whales, and |
https://en.wikipedia.org/wiki/Sylvester%27s%20criterion | In mathematics, Sylvester’s criterion is a necessary and sufficient criterion to determine whether a Hermitian matrix is positive-definite. It is named after James Joseph Sylvester.
Sylvester's criterion states that a n × n Hermitian matrix M is positive-definite if and only if all the following matrices have a positive determinant:
the upper left 1-by-1 corner of M,
the upper left 2-by-2 corner of M,
the upper left 3-by-3 corner of M,
M itself.
In other words, all of the leading principal minors must be positive. By using appropriate permutations of rows and columns of M, it can also be shown that the positivity of any nested sequence of n principal minors of M is equivalent to M being positive-definite.
An analogous theorem holds for characterizing positive-semidefinite Hermitian matrices, except that it is no longer sufficient to consider only the leading principal minors:
a Hermitian matrix M is positive-semidefinite if and only if all principal minors of M are nonnegative.
Simple proof for special case
Suppose is Hermitian matrix . Let be the principal minor matrices, i.e. the upper left corner matrices. It will be shown that if is positive definite, then the principal minors are positive; that is, for all .
is positive definite. Indeed, choosing
we can notice that Equivalently, the eigenvalues of are positive, and this implies that since the determinant is the product of the eigenvalues.
To prove the reverse implication, we use induction. The general form of an Hermitian matrix is
,
where is an Hermitian matrix, is a vector and is a real constant.
Suppose the criterion holds for . Assuming that all the principal minors of are positive implies that , , and that is positive definite by the inductive hypothesis. Denote
then
By completing the squares, this last expression is equal to
where (note that exists because the eigenvalues of are all positive.)
The first term is positive by the inductive hypothesis. We now exam |
https://en.wikipedia.org/wiki/Analog%20device | Analog devices are a combination of both analog machine and analog media that can together measure, record, reproduce, receive or broadcast continuous information, for example, the almost infinite number of grades of transparency, voltage, resistance, rotation, or pressure. In theory, the continuous information in an analog signal has an infinite number of possible values with the only limitation on resolution being the accuracy of the analog device.
Analog media are materials with analog properties, such as photographic film, which are used in analog devices, such as cameras.
Example devices
Non-electrical
There are notable non-electrical analog devices, such as some clocks (sundials, water clocks), the astrolabe, slide rules, the governor of a steam engine, the planimeter (a simple device that measures the surface area of a closed shape), Kelvin's mechanical tide predictor, acoustic rangefinders, servomechanisms (e.g. the thermostat), a simple mercury thermometer, a weighing scale, and the speedometer.
Electrical
The telautograph is an analogue precursor to the modern fax machine. It transmits electrical impulses recorded by potentiometers to stepping motors attached to a pen, thus being able to reproduce a drawing or signature made by the sender at the receiver's station. It was the first such device to transmit drawings to a stationary sheet of paper; previous inventions in Europe used rotating drums to make such transmissions.
An analog synthesizer is a synthesizer that uses analog circuits and analog computer techniques to generate sound electronically.
The analog television encodes television and transports the picture and sound information as an analog signal, that is, by varying the amplitude and/or frequencies of the broadcast signal. All systems preceding digital television, such as NTSC, PAL, and SECAM are analog television systems.
An analog computer is a form of computer that uses electrical, mechanical, or hydraulic phenomena to model the probl |
https://en.wikipedia.org/wiki/Battery%20indicator | A battery indicator (also known as a battery gauge) is a device which gives information about a battery. This will usually be a visual indication of the battery's state of charge. It is particularly important in the case of a battery electric vehicle.
Automobiles
Some automobiles are fitted with a battery condition meter to monitor the starter battery. This meter is, essentially, a voltmeter but it may also be marked with coloured zones for easy visualization.
Many newer cars no longer offer voltmeters or ammeters; instead, these vehicles typically have a light with the outline of an automotive battery on it. This can be somewhat misleading as it may be confused for an indicator of a bad battery when in reality it indicates a problem with the vehicle's charging system.
Alternatively, an ammeter may be fitted. This indicates whether the battery is being charged or discharged. In the adjacent picture, the ammeter is marked "Alternator" and the symbols are "C" (charge) and "D" (discharge).
Both ammeters and voltmeters individually or together can be used to assess the operating state of an automobile battery and charging system.
Electronic devices
A battery indicator is a feature of many electronic devices. In mobile phones, the battery indicator usually takes the form of a bar graph - the more bars that are showing, the better the battery's state of charge.
Computers
Computers may give a signal to users that an internal standby battery needs replacement. Portable computers using rechargeable batteries generally give the user some indication of the remaining operating time left on the battery. A Smart Battery System uses a controller integrated with an interchangeable battery pack to provide a more accurate indication of the state of battery charge.
Batteries not part of a system
Batteries that are part of a system, such as computer batteries, can have their properties checked and logged in operation to assist in determining remaining charge. A real bat |
https://en.wikipedia.org/wiki/Plane%20mirror | A plane mirror is a mirror with a flat (planar) reflective surface. For light rays striking a plane mirror, the angle of reflection equals the angle of incidence. The angle of the incidence is the angle between the incident ray and the surface normal (an imaginary line perpendicular to the surface). Therefore, the angle of reflection is the angle between the reflected ray and the normal and a collimated beam of light does not spread out after reflection from a plane mirror, except for diffraction effects.
A plane mirror makes an image of objects in front of the mirror; these images appear to be behind the plane in which the mirror lies. A straight line drawn from part of an object to the corresponding part of its image makes a right angle with, and is bisected by, the surface of the plane mirror. The image formed by a plane mirror is virtual (meaning that the light rays do not actually come from the image) it is not real image (meaning that the light rays do actually come from the image). it is always upright, and of the same shape and size as the object it is reflecting. A virtual image is a copy of an object formed at the location from which the light rays appear to come. Actually, the image formed in the mirror is a perverted image (Perversion), there is a misconception among people about having confused with perverted and laterally-inverted image. If a person is reflected in a plane mirror, the image of his right hand appears to be the left hand of the image.
Plane mirrors are the only type of mirror for which a object produces an image that is virtual, erect and of the same size as the object in all cases irrespective of the shape, size and distance from mirror of the object however same is possible for other types of mirror (concave and convex) but only for a specific conditions . However the focal length of a plane mirror is infinity; its optical power is zero.
Using the mirror equation, where is the object distance, is the image distance, and is the |
https://en.wikipedia.org/wiki/Cap%20Gemini%20SDM | Cap Gemini SDM, or SDM2 (System Development Methodology) is a software development method developed by the software company Pandata in the Netherlands in 1970. The method is a waterfall model divided in seven phases that have a clear start and end. Each phase delivers subproducts, called milestones. It was used extensively in the Netherlands for ICT projects in the 1980s and 1990s. Pandata was purchased by the Capgemini group in the 1980s, and the last version of SDM to be published in English was SDM2 (6th edition) in 1991 by Cap Gemini Publishing BV. The method was regularly taught and distributed among Capgemini consultants and customers, until the waterfall method slowly went out of fashion in the wake of more iterative extreme programming methods such as Rapid application development, Rational Unified Process and Agile software development.
The Cap Gemini SDM Methodology
In the early to mid-1970s, the various generic work steps of system development methodologies were replaced with work steps based on various structured analysis or structured design techniques. SDM, SDM2, SDM/70, and Spectrum evolved into system development methodologies that were based on the works of Steven Ward, Tom Demarco, Larry Constantine, Ken Orr, Ed Yourdon, Michael A. Jackson and others, as well as data modeling techniques developed by Thomas Bachmann and Peter Chen. SDM is a top-down model. Starting from the system as a whole, its description becomes more detailed as the design progresses. The method was marketed as a proprietary method that all company developers were required to use to ensure quality in customer projects. This method shows several similarities with the proprietary methods of CAP Gemini's most important competitors in 1990. A similar waterfall method that was later used against the company itself in court proceedings in 2002 was CMG:Commander.
History
SDM was developed in 1970 by a company known as PANDATA, now part of Cap Gemini, which itself was created as a |
https://en.wikipedia.org/wiki/American%20Sign%20Museum | The American Sign Museum in Cincinnati, Ohio, preserves, archives, and displays a collection of signs. The museum also displays the equipment utilized in the design and manufacture of signs. Tod Swormstedt began working on the museum in 1999. It opened to the public in 2005.
Background
Swormstedt's family owns the signage industry trade journal Signs of the Times, which has been published since 1906. Swormstedt's grandfather, H.C. Menefee, was the first editor of the publication, and purchased it for himself in 1911. Swormstedt had been working at the journal for over twenty years before becoming inspired to start a sign museum in 1999. His family provided $1 million for the project, and figures from the signage industry gave donations of their own. The museum was founded as a nonprofit corporation. Swormstedt considered building the museum in Los Angeles, St. Louis, Memphis, and other sites, but eventually settled on Cincinnati, the base of operations for Signs of the Times.
Collection
Over 200 signs and other objects are on display at the museum, and over 3,800 items are cataloged. The collection ranges from the late nineteenth century to the 1970s. Highlights of the collection include samples of gold leaf lettering on glass, a Sputnik-like plastic orb from an Anaheim shopping center, a rotating neon windmill from a Denver donut shop, Las Vegas showcards, and a fiberglass Frisch's Big Boy statue with a slingshot in his pocket. (The slingshot was omitted from later models of the Big Boy statue.) One can also find signs from businesses such as Big Bear Stores, Howard Johnson's, and Earl Scheib. Over the museum's entrance, visitors are greeted by a fiberglass genie from a Los Angeles carpet company.
In 2008, the museum acquired a single-arch 1963 McDonald's sign from Huntsville, Alabama. The sign features McDonald's Speedee character, who was phased out in favor of Ronald McDonald in the 1960s. In 2009, the museum added a neon sign from Johnny’s Big Red Grill, o |
https://en.wikipedia.org/wiki/Phosphoribosylaminoimidazole%20carboxylase | The enzyme Phosphoribosylaminoimidazole carboxylase, or AIR carboxylase () is involved in nucleotide biosynthesis and in particular in purine biosynthesis. It catalyzes the conversion of 5'-phosphoribosyl-5-aminoimidazole ("AIR") into 5'-phosphoribosyl-4-carboxy-5-aminoimidazole ("CAIR") as described in the reaction:
5-aminoimidazole ribonucleotide + CO2 5'-phosphoribosyl-4-carboxy-5-aminoimidazole + 2 H+
In plants and fungi
Phosphoribosylaminoimidazole carboxylase is a fusion protein in plants and fungi, but consists of two non-interacting proteins in bacteria, PurK and PurE.
The crystal structure of PurE indicates a unique quaternary structure that confirms the octameric nature of the enzyme.
In Escherichia coli
In the bacterium Escherichia coli the reaction is catalyzed in two steps carried out by two separate enzymes, PurK and PurE.
PurK, N5-carboxyaminoimidazole ribonucleotide synthetase, catalyzes the conversion of 5-aminoimidazole ribonucleotide ("AIR"), ATP, and bicarbonate to N5-carboxyaminoimidazole ribonucleotide ("N5-CAIR"), ADP, and phosphate.
PurE, N5-carboxyaminoimidazole ribonucleotide mutase, converts N5-CAIR to CAIR, the sixth step of de novo purine biosynthesis. In the presence of high concentrations of bicarbonate, PurE is reported able to convert AIR to CAIR directly and without ATP. Some members of this family contain two copies of this domain. |
https://en.wikipedia.org/wiki/AICA%20ribonucleotide | 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR) is an intermediate in the generation of inosine monophosphate. AICAR is an analog of adenosine monophosphate (AMP) that is capable of stimulating AMP-dependent protein kinase (AMPK) activity. The drug has also been shown as a potential treatment for diabetes by increasing the metabolic activity of tissues by changing the physical composition of muscle.
Mechanism of action
The nucleoside form of AICAR, acadesine, is an analog of adenosine that enters cardiac cells to inhibit adenosine kinase and adenosine deaminase. It enhances the rate of nucleotide re-synthesis increasing adenosine generation from adenosine monophosphate only during conditions of myocardial ischemia. In cardiac myocytes, acadesine is phosphorylated to AICAR to activate AMPK without changing the levels of the nucleotides. AICAR is able to enter the de novo synthesis pathway for adenosine synthesis to inhibit adenosine deaminase causing an increase in ATP levels and adenosine levels.
Use as a performance-enhancing drug
In 2009, the French Anti-Doping Agency, suspected that AICAR had been used in the 2009 Tour de France for its supposed performance enhancing properties. Although a detection method was reportedly given to the World Anti-Doping Agency, it was unknown if this method was implemented. As of January 2011, AICAR was officially a banned substance in the World Anti Doping Code, and the standard levels in elite athletes have been determined, to interpret test results.
See also
Inosine monophosphate synthase
Nicotinamide riboside |
https://en.wikipedia.org/wiki/Inosine%20monophosphate%20synthase | Bifunctional purine biosynthesis protein PURH is a protein that in humans is encoded by the ATIC gene.
ATIC encodes an enzyme which generates inosine monophosphate from aminoimidazole carboxamide ribonucleotide.
It has two functions:
- 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase
- IMP cyclohydrolase |
https://en.wikipedia.org/wiki/Shear%20force | In solid mechanics, shearing forces are unaligned forces acting on one part of a body in a specific direction, and another part of the body in the opposite direction. When the forces are collinear (aligned with each other), they are called tension forces or compression forces. Shear force can also be defined in terms of planes: "If a plane is passed through a body, a force acting along this plane is called a shear force or shearing force."
Force required to shear steel
This section calculates the force required to cut a piece of material with a shearing action. The relevant information is the area of the material being sheared, ie the area across which the shearing action takes place, and the shear strength of the material. A round bar of steel is used as an example. The shear strength is calculated from the tensile strength using a factor which relates the two strengths. In this case 0.6 applies to the example steel, known as EN8 bright, although it can vary from 0.58–0.62 depending on application.
EN8 bright has a tensile strength of 800MPa and mild steel, for comparison, has a tensile strength of 400MPa.
To calculate the force to shear a 25 mm diameter bar of EN8 bright steel;
area of the bar in mm2 = (12.52)(π) ≈ 490.8mm2
0.8kN/mm2 × 490.8mm2 = 392.64kN ≈ 40tonne-force
40tonne-force × 0.6 (to change force from tensile to shear) = 24tonne-force
When working with a riveted or tensioned bolted joint, the strength comes from friction between the materials bolted together. Bolts are correctly torqued to maintain the friction. The shear force only becomes relevant when the bolts are not torqued.
A bolt with property class 12.9 has a tensile strength of 1200MPa (1MPa = 1N/mm2) or 1.2kN/mm2 and the yield strength is 0.90 times tensile strength, 1080MPa in this case.
A bolt with property class 4.6 has a tensile strength of 400MPa (1MPa = 1N/mm2) or 0.4 kN/mm2 and yield strength is 0.60 times tensile strength, 240MPa in this case.
See also
ASTM F568M, mechanical |
https://en.wikipedia.org/wiki/N-version%20programming | N-version programming (NVP), also known as multiversion programming or multiple-version dissimilar software, is a method or process in software engineering where multiple functionally equivalent programs are independently generated from the same initial specifications. The concept of N-version programming was introduced in 1977 by Liming Chen and Algirdas Avizienis with the central conjecture that the "independence of programming efforts will greatly reduce the probability of identical software faults occurring in two or more versions of the program". The aim of NVP is to improve the reliability of software operation by building in fault tolerance or redundancy.
NVP approach
The general steps of N-version programming are:
An initial specification of the intended functionality of the software is developed. The specification should unambiguously define: functions, data formats (which include comparison vectors, c-vectors, and comparison status indicators, cs-indicators), cross-check points (cc-points), comparison algorithm, and responses to the comparison algorithm.
From the specifications, two or more versions of the program are independently developed, each by a group that does not interact with the others. The implementations of these functionally equivalent programs use different algorithms and programming languages. At various points of the program, special mechanisms are built into the software which allow the program to be governed by the N-version execution environment (NVX). These special mechanisms include: comparison vectors (c-vectors, a data structure representing the program's state), comparison status indicators (cs-indicators), and synchronization mechanisms. The resulting programs are called N-version software (NVS).
Some N-version execution environment (NVX) is developed which runs the N-version software and makes final decisions of the N-version programs as a whole given the output of each individual N-version program. The implementation of t |
https://en.wikipedia.org/wiki/4-Hydroxyphenylpyruvic%20acid | 4-Hydroxyphenylpyruvic acid (4-HPPA) is an intermediate in the metabolism of the amino acid phenylalanine. The aromatic side chain of phenylalanine is hydroxylated by the enzyme phenylalanine hydroxylase to form tyrosine. The conversion from tyrosine to 4-HPPA is in turn catalyzed by tyrosine aminotransferase. Additionally, 4-HPPA can be converted to homogentisic acid which is one of the precursors to ochronotic pigment.
It is an intermediary compound in the biosynthesis of scytonemin.
See also
4-Hydroxyphenylpyruvate dioxygenase |
https://en.wikipedia.org/wiki/Fumarylacetoacetic%20acid | Fumarylacetoacetic acid (fumarylacetoacetate) is an intermediate in the metabolism of tyrosine. It is formed through the conversion of maleylacetoacetate into fumarylacetoacetate by the enzyme maleylacetoacetate isomerase.
See also
Fumarylacetoacetate hydrolase |
https://en.wikipedia.org/wiki/Artificial%20enzyme | An artificial enzyme is a synthetic organic molecule or ion that recreates one or more functions of an enzyme. It seeks to deliver catalysis at rates and selectivity observed in naturally occurring enzymes.
History
Enzyme catalysis of chemical reactions occur with high selectivity and rate. The substrate is activated in a small part of the enzyme's macromolecule called the active site. There, the binding of a substrate close to functional groups in the enzyme causes catalysis by so-called proximity effects. It is possible to create similar catalysts from small molecules by combining substrate-binding with catalytic functional groups. Classically, artificial enzymes bind substrates using receptors such as cyclodextrin, crown ethers, and calixarene.
Artificial enzymes based on amino acids or peptides have expanded the field of artificial enzymes or enzyme mimics. For instance, scaffolded histidine residues mimic certain metalloproteins and enzymes such as hemocyanin, tyrosinase, and catechol oxidase).
Artificial enzymes have been designed from scratch via a computational strategy using Rosetta. A December 2014 publication reported active enzymes made from molecules that do not occur in nature. In 2016, a book chapter entitled "Artificial Enzymes: The Next Wave" was published.
Nanozymes
Nanozymes are nanomaterials with enzyme-like characteristics. They have been explored for applications such as biosensing, bioimaging, tumor diagnosis and therapy, and anti-biofouling.
1990s
In 1996 and 1997, Dugan et al. discovered superoxide dismutase (SOD)-mimicking activities of fullerene derivatives.
2000s
The term "nanozyme" was coined in 2004 by Flavio Manea, Florence Bodar Houillon, Lucia Pasquato, and Paolo Scrimin. A 2005 review article attributed this term to "analogy with the activity of catalytic polymers (synzymes)", based on the "outstanding catalytic efficiency of some of the functional nanoparticles synthesized". In 2006, nanoceria (CeO2 nanoparticles) was repo |
https://en.wikipedia.org/wiki/Program-associated%20data | Program Associated Data (PAD) or Program Service Data (PSD) is the data displayed on many HD Radio and satellite radio receivers. It can describe the program being transmitted and other information such as the name of the song, the artist and the genre of music.
The HD radio and satellite systems provides a data path for this programming data to be delivered and read by the listener in near real time. HD radio and satellite radio receivers provide PAD decoders and visual screens for displaying the information.
PAD is different from Radio Data System (RDS). |
https://en.wikipedia.org/wiki/RS-423 | RS-423, also known as TIA/EIA-423, is a technical standard originated by the Electronic Industries Alliance that specifies electrical characteristics of a digital signaling circuit. Although it was originally intended as a successor to RS-232C offering greater cable lengths, it is not widely used.
RS-423 systems can transmit data on cables as long as . It is closely related to RS-422, which used the same signaling systems but on a different wiring arrangement: RS-423 differed primarily in that it had a single return pin instead of one for each data pin.
RS-423 specifies an unbalanced (single-ended) interface, similar to RS-232, with a single, unidirectional sending driver, and allowing for up to 10 receivers. It is normally implemented in integrated circuit technology and can also be employed for the interchange of serial binary signals between DTE & DCE.
Standard scope
RS-423 is the common short form title of American National Standards Institute (ANSI) standard ANSI/TIA/EIA-423-B Electrical Characteristics of Unbalanced Voltage Digital Interface Circuits and its international equivalent ITU-T Recommendation T-REC-V.10, also known as X.26. These technical standards specify the electrical characteristics of the unbalanced voltage digital interface circuit. RS-423 provides for data transmission, using unbalanced or single-ended signals, with unidirectional/non-reversible, terminated or non-terminated transmission lines, point to point, or multi-drop.
Characteristics
RS-423 is closely related to the RS-422 standard, both of which use the same overall signaling system, but differ in that RS-422 has a dedicated return line for every data pin, while RS-423 uses a single return line. Use of a common ground is one weakness of RS-423 (and RS-232): if devices are far enough apart or on separate power systems, the ground will degrade between them and communications will fail, resulting in a condition that is difficult to trace.
RS-423 specifies the electrical character |
https://en.wikipedia.org/wiki/The%20Star%20Boarder%20%281914%20film%29 | The Star Boarder is a 1914 American short comedy film starring Charlie Chaplin.
The film is also known as The Landlady's Pet, its 1918 American reissue title.
Synopsis
Charlie, a resident in a boarding house, is the favorite of his landlord's wife. His fellow male boarders are jealous of the situation and dislike Charlie because of it. They arrange to frighten him with a dummy. Charlie is frightened and runs to the police. Meanwhile, a tramp has hidden himself in a cupboard. The police find him, making Charlie a hero for the moment. The mischievous young son of the landlord, however, has taken a series of compromising photographs and displays them to everyone in a magic lantern show. Two scandals are revealed: One photo shows Charlie kissing the proprietor's wife. Another shows the proprietor flirting with another woman.
The young son was played by Gordon Griffith. Four years later Griffith would play the young title character in the first movie adaptation of Tarzan of the Apes.
Review
Motion Picture News said of The Star Boarder, "[It is] a very funny comedy. The landlady is too familiar with the star boarder to suit her husband. He gets even, however, by going out with another woman."
Cast
Charles Chaplin as The Star Boarder
Minta Durfee as Landlady
Edgar Kennedy as Landlady's husband
Gordon Griffith as Their son
Alice Davenport as Landlady's friend
Phyllis Allen (uncredited boarder)
Jess Dandy (uncredited boarder)
Billy Gilbert (uncredited boarder)
Wallace MacDonald (uncredited boarder)
Harry McCoy (uncredited boarder)
Rube Miller (uncredited boarder)
Lee Morris (uncredited boarder)
William Nigh (uncredited boarder)
Al St. John (uncredited boarder)
Reception
Like many American films of the time, The Star Boarder was subject to restrictions and cuts by city and state film censorship boards. For example, the Chicago Board of Censors required, when the film was submitted for review for its 1918 reissue as The Landlady's Pet, cuts of Chaplin thumb |
https://en.wikipedia.org/wiki/Antiparallel%20lines | In geometry, two lines and are antiparallel with respect to a given line if they each make congruent angles with in opposite senses. More generally, lines and are antiparallel with respect to another pair of lines and if they are antiparallel with respect to the angle bisector of and
In any cyclic quadrilateral, any two opposite sides are antiparallel with respect to the other two sides.
Relations
The line joining the feet to two altitudes of a triangle is antiparallel to the third side. (any cevians which 'see' the third side with the same angle create antiparallel lines)
The tangent to a triangle's circumcircle at a vertex is antiparallel to the opposite side.
The radius of the circumcircle at a vertex is perpendicular to all lines antiparallel to the opposite sides. |
https://en.wikipedia.org/wiki/Antiparallel%20%28biochemistry%29 | In biochemistry, two biopolymers are antiparallel if they run parallel to each other but with opposite directionality (alignments). An example is the two complementary strands of a DNA double helix, which run in opposite directions alongside each other.
Nucleic acids
Nucleic acid molecules have a phosphoryl (5') end and a hydroxyl (3') end. This notation follows from organic chemistry nomenclature, and can be used to define the movement of enzymes such as DNA polymerases relative to the DNA strand in a non-arbitrary manner.
G-quadruplexes
G-quadruplexes, also known as G4 DNA are secondary structures found in nucleic acids that are rich in guanine. These structures are normally located at the telomeres (the ends of the chromosomes). The G-quadruplex can either be parallel or antiparallel depending on the loop configuration, which is a component of the structure. If all the DNA strands run in the same direction, it is termed to be a parallel quadruplex, and is known as a strand-reversal/propeller, connecting adjacent parallel strands. If one or more of the DNA strands run in opposite direction, it is termed as an anti-parallel quadruplex, and can either be in a form of a lateral/edgewise, connecting adjacent anti-parallel strands, or a diagonal, joining two diagonally opposite strands. The structure of these G-quadruplexes can be determined by a cation.
DNA replication
In DNA, the 5' carbon is located at the top of the leading strand, and the 3' carbon is located at the lower section of the lagging strand. The nucleic acid sequences are complementary and parallel, but they go in opposite directions, hence the antiparallel designation. The antiparallel structure of DNA is important in DNA replication because it replicates the leading strand one way and the lagging strand the other way. During DNA replication, the leading strand is replicated continuously whereas the lagging strand is replicated in segments known as Okazaki fragments.
Anti-parallelism in biochemi |
https://en.wikipedia.org/wiki/Antiparallel%20%28electronics%29 | In electronics, two anti-parallel or inverse-parallel devices are connected in parallel but with their polarities reversed.
One example is the TRIAC, which is comparable to two thyristors connected back-to-back (in other words, reverse parallel), but on a single piece of silicon.
Two LEDs can be paired this way, so that each protects the other from reverse voltage. A series string of such pairs can be connected to AC or DC power, with an appropriate resistor. Some two-color LEDs are constructed this way, with the 2 dies connected anti-parallel in one chip package. With AC, the LEDs in each pair take turns emitting light, on alternate half-cycles of supply power, greatly reducing the strobing effect to below the normal flicker fusion threshold of the human eye, and making the lights brighter. On DC, polarity can be switched back and forth so as to change the color of the lights, such as in Christmas lights that can be either white or colored.
Battery-powered lights, which are wired in parallel, can also create a simulated "chasing" effect by alternating the polarity for each LED attached to the string, and controlling the positive and negative parts of the cycle separately. This creates two "virtual circuits", with odd-numbered LEDs lighting on positive polarity and even-numbered ones on negative polarity, for example. By eliminating the need for extra wires, this reduces costs for the manufacturer, and makes the cords less bulky and obvious for the consumer to string on decorative items. On cheaper sets, this causes strobing and prevents any of the LEDs from getting to full brightness, since both polarities share the same wire pair and cannot be active at the same time, meaning each can only be on during its own half of the cycle. Better lights can adjust the duty cycle so that any unused "off" time on one polarity can be used by the other, reducing the strobing effect and making it easier to create color blends (such as orange, amber, and yellow from a |
https://en.wikipedia.org/wiki/Seagate%20SeaShield | Seagate SeaShield was a physical electrostatic protection shield feature of Seagate Medalist series hard drives, and followed by the Barracuda series of hard disk drives.
Physical characteristics
There are two types of Sea Shield:
The first version of the shield is made of two pieces. The top is made of metal and serves as physical protection for the electronics. The other half is mounted on the bottom side of hard drive, and is fastened with a metal hook to the electronics board with two Torx screws. The metal shield covers the electronic circuit and electronic cables leading to the hard disk drive motor and drive head. Below the metal shield, there is a layer of foam, which serves as the actual electrostatic protection.
The second version of the shield is included on many models from the U series. This one-piece approach replaced the metal and foam with rubber. However, this version was a bit less intelligible as rubber is also a heat insulator and has been blamed for failures of aging drives.
Other purpose
The metal shield is covered with a plastic label, which contains instructions on disk installation, and various physical jumper setups.
Future
The SeaShield has disappeared from modern hard drives, and although no other hard drive manufacturer has ever used similar protection on their hard drives, some companies such as WiebeTech Micro Storage Solutions do offer a plate which can be screwed onto the bottom of SATA or IDE drives, protecting the circuitry.
External resources
Seagate Barracuda SATA V Review https://web.archive.org/web/20020918012352/http://www.lostcircuits.com/advice/sata150/10.shtml
Russian Baracuda SATA Review http://www.composter.ru/Environ/wa/Main?textid=3792&level1=articles
WiebeTech Misc Products and Accessories (with pricing) http://www.wiebetech.com/products/misc.php
Computer storage devices
Hard disk drives |
https://en.wikipedia.org/wiki/Wildlife%20corridor | A wildlife corridor, habitat corridor, or green corridor is an area of habitat connecting wildlife populations separated by human activities or structures (such as roads, development, or logging). This allows an exchange of individuals between populations, which may help prevent the negative effects of inbreeding, and reduced genetic diversity (via genetic drift) that often occur within isolated populations. Corridors may also help facilitate the re-establishment of populations that have been reduced or eliminated due to random events (such as fires or disease). This may potentially moderate some of the worst effects of habitat fragmentation, wherein urbanization can split up habitat areas, causing animals to lose both their natural habitat and the ability to move between regions to access resources. Habitat fragmentation due to human development is an ever-increasing threat to biodiversity, and habitat corridors serve to manage its effects.
Purpose
Habitat corridors can be considered a management tool in places where the destruction of a natural area has greatly affected its native species, whether as a result of human development or natural disasters. When areas of land are broken up, populations can become unstable or fragmented. Corridors can reconnect fragmented populations and reduce population fluctuations by contributing to three factors that can help to stabilize a population:
Colonization—animals are able to move and occupy new areas when food sources or other natural resources are lacking in their core habitat.
Migration—species that relocate seasonally can do so more safely and effectively when it does not interfere with human development barriers.
Interbreeding—animals can find new mates in neighboring regions, increasing genetic diversity.
Rosenberg et al. were among the first to define what constitutes a wildlife corridor, developing a conceptual model that emphasized the role of a wildlife corridor as a facilitator of movement that is not rest |
https://en.wikipedia.org/wiki/ReCAPTCHA | reCAPTCHA Inc. is a CAPTCHA system owned by Google. It enables web hosts to distinguish between human and automated access to websites. The original version asked users to decipher hard to read text or match images. Version 2 also asked users to decipher text or match images if the analysis of cookies and canvas rendering suggested the page was being downloaded automatically. Since version 3, reCAPTCHA will never interrupt users and is intended to run automatically when users load pages or click buttons.
The original iteration of the service was a mass collaboration platform designed for the digitization of books, particularly those that were too illegible to be scanned by computers. The verification prompts utilized pairs of words from scanned pages, with one known word used as a control for verification, and the second used to crowdsource the reading of an uncertain word. reCAPTCHA was originally developed by Luis von Ahn, David Abraham, Manuel Blum, Michael Crawford, Ben Maurer, Colin McMillen, and Edison Tan at Carnegie Mellon University's main Pittsburgh campus. It was acquired by Google in September 2009. The system helped to digitize the archives of The New York Times, and was subsequently used by Google Books for similar purposes.
The system was reported as displaying over 100 million CAPTCHAs every day, on sites such as Facebook, TicketMaster, Twitter, 4chan, CNN.com, StumbleUpon, Craigslist (since June 2008), and the U.S. National Telecommunications and Information Administration's digital TV converter box coupon program website (as part of the US DTV transition).
In 2014, Google pivoted the service away from its original concept, with a focus on reducing the amount of user interaction needed to verify a user, and only presenting human recognition challenges (such as identifying images in a set that satisfy a specific prompt) if behavioral analysis suspects that the user may be a bot.
In 2023, reCAPTCHAs were found to be obsolete due to improvements i |
https://en.wikipedia.org/wiki/6%2C7-Dimethyl-8-ribityllumazine | 6,7-Dimethyl-8-ribityllumazine is a precursor for riboflavin. It is acted upon by riboflavin synthase.
Pteridines
Imides |
https://en.wikipedia.org/wiki/Shadow%20RAM%20%28Acorn%29 | Shadow RAM, on the Acorn BBC Micro, Master-series and Acorn Electron microcomputers is the name given to a special framebuffer implementation to free up main memory for use by program code and data. Some implementations of shadow RAM also permit double-buffered graphics.
Background
The BBC Micro, Master-series and Electron machines use the 8-bit 6502 and 65C102 processors with a 16-bit address space. This address space is split into 32 KB RAM (0x0000 to 0x7FFF), 16 KB sideways "paged" address space (0x8000 to 0xBFFF) and 16 KB operating system space (0xC000 to 0xFFFF). Video or screen memory is typically allocated from 0x7FFF downwards as necessary, occupying as little as 1 KB for Teletext mode 7 (and thus the region from 0x7C00 to 0x7FFF), or as much as 20 KB for modes 0-2 (and thus the region from 0x3000 to 0x7FFF). Thus, screen memory can therefore occupy a considerable amount of the available directly-addressed 32 KB RAM.
Overview
Shadow RAM is a block of RAM that can be considered to reside in parallel to the normal memory map and is accessed by the system only under certain conditions. When shadow RAM is enabled, the memory region normally used for screen memory becomes available for BASIC program use and for applications employing officially documented operating system interfaces. Given the maximum requirement of 20 KB for screen memory with the systems concerned, the amount of shadow RAM provided is typically 20 KB.
Shadow RAM was fitted as standard on the BBC Micro Model B+ and on the BBC Master series, but was an optional feature provided by third-party expansions on earlier BBC Micro systems and the Acorn Electron. The Aries-B20 product, initially sold by Cambridge Computer Consultants, offered 20 KB shadow RAM for the BBC Model B, transparently diverting non-framebuffer accesses to the shadow RAM for addresses in the 20 KB video memory region.
In systems based on the BBC Model B+, like the Acorn Cambridge Workstation, a programmable array logic ( |
https://en.wikipedia.org/wiki/Deoxyuridine%20monophosphate | Deoxyuridine monophosphate (dUMP), also known as deoxyuridylic acid or deoxyuridylate in its conjugate acid and conjugate base forms, respectively, is a deoxynucleotide.
It is an intermediate in the metabolism of deoxyribonucleotides.
Biosynthesis
Deoxyuridine monophosphate (dUMP) is the deoxygenated form of uridine monophosphate (UMP), and is the precursor to deoxythymidine monophosphate (dTMP), a component of DNA nucleotide biosynthesis. By replacing the hydroxyl group at the 2' carbon of ribose with a hydrogen, UMP becomes deoxygenated to dUMP.
The synthesis of deoxyuridine monophosphate (dUMP) is a multi-step process that begins with uridine monophosphate (UMP), the product of pyrimidine biosynthesis. The enzyme nucleoside monophosphate kinase converts UMP and ATP to uridine diphosphate (UDP) and ADP.
In the presence of excess ATP, the enzyme ribonucleotide reductase initiates a chain reaction with UDP, which catalyzes the formation of deoxyuridine diphosphate (dUDP), which is then converted to deoxyuridine triphosphate (dUTP), then deoxyuridine monophosphate (dUMP) via the addition or removal of phosphate groups.
Interactive pathway map
See also
DCMP deaminase
Uridine monophosphate
Notes
Nucleotides |
https://en.wikipedia.org/wiki/Sideways%20address%20space | The sideways address space on the Acorn BBC Microcomputer, Electron and Master-series microcomputer was Acorn's bank switching implementation, providing for permanent system expansion in the days before hard disk drives or even floppy disk drives were commonplace. Filing systems, application and utility software, and drivers were made available as sideways ROMs, and extra RAM could be fitted via the sideways address space.
The BBC Micro Advanced User Guide refers to the sideways address space as "paged ROMs" because it predated the use of this address space for RAM expansion. The BBC B+, B+ 128 and BBC Master all featured sideways RAM as standard.
Sideways address space
The machines used the 8-bit 6502 and 65C102 processors with a 16-bit address space. The address space was split into 32 KB RAM (0x0000 to 0x7FFF), 16 KB sideways address space (0x8000 to 0xBFFF) and 16 KB operating system space (0xC000 to 0xFFFF).
The sideways address space is a bank-switched (referred to by Acorn as "paged") address space that allows access to one 16 KB bank at a time. Each bank can be ROM or RAM.
On both the BBC Micro and the BBC Master, there are ROM sockets on the motherboard (four on the BBC Micro) which take sideways ROMs. The BBC Micro shipped with a single ROM, containing BBC BASIC; further ROMs can be added to the computer to add software that will remain available at all times. The Electron's sideways address space was exposed only by the addition of a Plus 1 add-on or a third-party equivalent; the Plus 1 also introduced cartridge slots that were carried over into the BBC Master design as an alternative way to package ROMs.
Sideways ROMs permitted the addition of new filing systems to the OS (such as the Disc Filing System) and application and utility software. Software supplied as ROMs has two main benefits: it loads instantaneously (if delivered as language or service ROMs), and it requires very little RAM to operate (and may use the dedicated paged ROM area of RAM |
https://en.wikipedia.org/wiki/Miniat%C3%BCrk | Miniatürk is a miniature park at the northeastern shore of Golden Horn in Istanbul, Turkey. It opened May 2, 2003. It is one of the world's largest miniature parks, with a model area and total area of . It contains 135 models, in 1:25 scale, of structures from in and around Turkey, and interpretations of historic structures.
Of the park's total area, is open space; is covered; and contain pools and waterways. Its parking lot has a capacity of 300 vehicles.
60 of the park's structures are from Istanbul, 63 are from Anatolia, and 13 are from the Ottoman territories that today lie outside Turkey. Also featured are historic structures like the Temple of Artemis at Ephesus, and the Mausoleum of Maussollos at Halicarnassus (now Bodrum). Additional space is reserved for future models. |
https://en.wikipedia.org/wiki/Phosphohydroxypyruvic%20acid | Phosphohydroxypyruvic acid is an organic acid most widely known as an intermediate in the synthesis of serine.
Chemical properties
Phosphohydroxypyruvic acid is a moderately weak acid. |
https://en.wikipedia.org/wiki/%C3%89l%20%28video%20game%29 | ELLE, also known as , is a Japanese adult visual novel developed by ELF Corporation which was originally released on June 13, 1991. A remake produced by ELF Corporation retitled Él was released on September 29, 2000. Green Bunny produced an anime original video animation titled Él which was released in two volumes in 2001. The series depicts the survivors of a nuclear war that are gathered in a single, tightly monitored city.
Plot
In December 1999, a nuclear war devastates the Earth and renders most of the world inhospitable. To ensure the survival of humanity the "Megaroasu plan" is carried out, but a terrorist organization called the Black Widow attacks and tries to disrupt the plan. The story takes place in 2008. The player takes the role of an unnamed Hero with an unknown past who is an expert marksman. The heroine is El Miles, and includes an ensemble of minor characters to advance the plot. The game is a simple click adventure with only one ending as with many games of the genre.
For the 2000 remake, the story was the same with the exception of the setting being refocused to 2030. The graphics were updated and included three-dimensional computer graphics. The script was dubbed by a cast of professional voice actors, but the cast credits were private and not released.
OVA plot
After a nuclear war triggered by environmental pollution, a group of survivors start the Megaro Earth Project, a city built under a dome to protect the last fragments of humanity. El Miles is a "sniper" – a policewoman defending the city against the terrorist organization Black Widow. El has been placed in charge of protecting Parsley, a pop singer nearly raped by Black Widow operatives. The singer then finds herself falling in love with El, and attempts to seduces her. El discovers that some of her fellow snipers are becoming Black Widow operatives, and she is constantly tormented not only by their leader Gimmick, but also by unusual blackouts and of unexplained visions of another r |
https://en.wikipedia.org/wiki/Bowyer%E2%80%93Watson%20algorithm | In computational geometry, the Bowyer–Watson algorithm is a method for computing the Delaunay triangulation of a finite set of points in any number of dimensions. The algorithm can be also used to obtain a Voronoi diagram of the points, which is the dual graph of the Delaunay triangulation.
Description
The Bowyer–Watson algorithm is an incremental algorithm. It works by adding points, one at a time, to a valid Delaunay triangulation of a subset of the desired points. After every insertion, any triangles whose circumcircles contain the new point are deleted, leaving a star-shaped polygonal hole which is then re-triangulated using the new point. By using the connectivity of the triangulation to efficiently locate triangles to remove, the algorithm can take O(N log N) operations to triangulate N points, although special degenerate cases exist where this goes up to O(N2).
History
The algorithm is sometimes known just as the Bowyer Algorithm or the Watson Algorithm. Adrian Bowyer and David Watson devised it independently of each other at the same time, and each published a paper on it in the same issue of The Computer Journal (see below).
Pseudocode
The following pseudocode describes a basic implementation of the Bowyer-Watson algorithm. Its time complexity is . Efficiency can be improved in a number of ways. For example, the triangle connectivity can be used to locate the triangles which contain the new point in their circumcircle, without having to check all of the triangles - by doing so we can decrease time complexity to . Pre-computing the circumcircles can save time at the expense of additional memory usage. And if the points are uniformly distributed, sorting them along a space filling Hilbert curve prior to insertion can also speed point location.
function BowyerWatson (pointList)
// pointList is a set of coordinates defining the points to be triangulated
triangulation := empty triangle mesh data structure
add super-triangle to triangulation // m |
https://en.wikipedia.org/wiki/RAI1 | RAI1 is a transcription factor associated with Smith–Magenis syndrome when individuals have deletions of the gene and Potocki–Lupski syndrome when individuals have a duplication. It is known as retinoic acid induced 1.
See also
Retinoic acid
External links
GeneReviews/NIH/NCBI/UW entry on Smith-Magenis Syndrome |
https://en.wikipedia.org/wiki/Black%20doll | A Black doll is a doll of a black person. Black doll manufacture dates back to the 19th century, with representations being both realistic and stereotypical. More accurate, mass-produced depictions are manufactured today as toys and adult collectibles.
European manufacture
Several 19th-century European doll companies preceded American doll companies in manufacturing Black dolls. These predecessors include Carl Bergner of Germany, who made a three-faced doll with one face of a crying black child and the other two, happier white faces. In 1892, Jumeau of Paris advertised Black and mixed-race dolls with bisque heads. Gebruder Heubach of Germany made character faces in bisque. Other European doll makers include Bru Jne. & Cie and Société Française de Fabrication de Bébés et Jouets (S.F.B.J.) of France, and Kestner and Steiner of Germany.
American manufacture
American entrepreneur Richard Henry Boyd founded the National Negro Doll Company in 1911 "after he tried to purchase dolls for his children but could find none that were not gross caricatures of African Americans."
American companies began including Black dolls in their doll lines in the early 1900s. Between 1910 and 1930, Horsman, Vogue, and Madame Alexander included Black dolls in their doll lines. Gradually, other American companies followed suit.
In 1947, the first African American woman cartoonist Jackie Ormes created the Patty-Jo doll, which was based on Patty-Jo 'n Ginger, the cartoon panel she penned for newspapers at the time. The doll was a realistic Black doll, breaking the mammy doll stereotype.
Beatrice Wright Brewington, an African American entrepreneur, founded B. Wright's Toy Company, Inc. and mass-produced Black dolls with ethnically-correct features. Also an educator, Wright began instructing girls in the art of making dolls in 1955.
During the 1960s and in the aftermath of the Watts Riots in Los Angeles, California, Shindana Toys, a Division of Operation Bootstrap, Inc., is credited as the |
https://en.wikipedia.org/wiki/Philip%20Franklin | Philip Franklin (October 5, 1898 – January 27, 1965) was an American mathematician and professor whose work was primarily focused in analysis.
Dr. Franklin received a B.S. in 1918 from City College of New York (who later awarded him its Townsend Harris Medal for the alumnus who achieved notable postgraduate distinction). He received his M.A. in 1920 and Ph.D. in 1921 both from Princeton University. His dissertation, The Four Color Problem, was supervised by Oswald Veblen. After teaching for one year at Princeton and two years at Harvard University (as the Benjamin Peirce Instructor), Franklin joined the Massachusetts Institute of Technology Department of Mathematics, where he stayed until his 1964 retirement.
In 1922, Franklin gave the first proof that all planar graphs with at most 25 vertices can be four-colored.
In 1928, Franklin gave the first description of an orthonormal basis for L²([0,1]) consisting of continuous functions (now known as "Franklin's system").
In 1934, Franklin disproved the Heawood conjecture for the Klein bottle by showing that any map drawn on the Klein bottle can be coloured with at most six colours. An example which shows that six colours may be needed is the 12-vertex cubic graph now known as the Franklin graph.
Franklin also worked with Jay W. Forrester on Project Whirlwind at the Office of Naval Research (ONR).
Franklin was editor of the MIT Journal of Mathematics and Physics from 1929.
In 1940 his comprehensive textbook A Treatise on Advanced Calculus was first published.
Franklin was married to Norbert Wiener's sister Constance. Their son-in-law is Václav E. Beneš.
Books |
https://en.wikipedia.org/wiki/Adenoiditis | Adenoiditis is the inflammation of the adenoid tissue usually caused by an infection. Adenoiditis is treated using medication (antibiotics and/or steroids) or surgical intervention.
Adenoiditis may produce cold-like symptoms. However, adenoiditis symptoms often persist for ten or more days, and often include pus-like discharge from nose.
The infection cause is usually viral. However, if the adenoiditis is caused by a bacterial infection, antibiotics may be prescribed for treatment. A steroidal nasal spray may also be prescribed in order to reduce nasal congestion. Severe or recurring adenoiditis may require surgical removal of the adenoids (adenotonsillectomy).
Signs and symptoms
Acute adenoiditis is characterized by fever, runny nose, nasal airway obstruction resulting in predominantly oral breathing, snoring and sleep apnea, Rhinorrhea with serous secretion in viral forms and mucous-purulent secretion in bacterial forms. In cases due to viral infection symptoms usually recede spontaneously after 48 hours, symptoms of bacterial adenoiditis typically persist up to a week. Adenoiditis is sometimes accompanied by tonsillitis. Repeated adenoiditis may lead to enlarged adenoids.
Complications
Complications of acute adenoiditis can occur due to extension of inflammation to the neighboring organs.
Cause
Viruses that may cause adenoiditis include adenovirus, rhinovirus and paramyxovirus. Bacterial causes include Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis and various species of Staphylococcus including Staphylococcus aureus.
Pathophysiology
It is currently believed that bacterial biofilms play an integral role in the harboring of chronic infection by tonsil and adenoid tissue so contributing to recurrent sinusitis and recurrent or persistent ear disease. Also, enlarged adenoids and tonsils may lead to the obstruction of the breathing patterns in children, causing apnea during sleep.
The most common bacteria isolated are Haemophilus influe |
https://en.wikipedia.org/wiki/I-cell | Fritz Heinrich Jakob Lewy, a German-American neurologist, first identified and described inclusions in the brain cells of patients with Parkinson’s disease and published his findings in the Lewandowsky’s Handbook of Neurology in 1912. I-cells also called inclusion cells are abnormal fibroblasts having a large number of dark inclusions in the cytoplasm of the cell (mainly in the central area). They are metabolically inactive structures of a cell and are not enclosed by a membrane. The inclusions are of various fats, proteins, carbohydrates, pigments, excretory products, crystals, and other insolubles. They are found in the cytoplasm of a cell in both prokaryotes and eukaryotes. They are seen in Mucolipidosis II, and Mucolipidosis III, also called inclusion-cell or I-cell disease where lysosomal enzyme transport and storage is affected. |
https://en.wikipedia.org/wiki/Microsoft%20Academic%20Search | Microsoft Academic Search was a research project and academic search engine retired in 2012. It relaunched in 2016 as Academic.
History
Microsoft launched a search tool called Windows Live Academic Search in 2006 to directly compete with Google Scholar. It was renamed Live Search Academic after its first year and then discontinued two years later. In 2009, Microsoft Research Asia Group launched a beta tool called Libra in 2009, which was for the purpose of algorithms research in object-level vertical search, data mining, entity linking, and data visualization. Libra was redirected to the MAS service by 2011 and contained 27.2 million records for books, conference papers, and journals.
Although largely functional, the service was not intended to be a production website and ceased to be developed, as was originally intended when the research goals of the project had been met. The service stopped being updated in 2012. The fact that this decline was not reported on earlier indicated to the authors that the service was largely ignored by academics and bibliometricians alike.
In July 2014, Microsoft Research announced that Microsoft Academic was evolving from a research project to a production service, and would be integrating with Microsoft's flagship search engine, Bing, and its intelligent personal assistant service, Cortana. “By growing Microsoft Academic Search from a research effort to production,” [Microsoft Research's Kuansan] Wang says, “our goal is to make Bing-powered Cortana the best personal research assistant for our users".
See also
Microsoft Academic
Google Scholar
CiteSeerX
Scirus
List of academic databases and search engines |
https://en.wikipedia.org/wiki/Evolution%3A%20The%20Game%20of%20Intelligent%20Life | Evolution: The Game of Intelligent Life is a life simulation and real-time strategy computer game that allows players to experience, guide, and control evolution from an isometric view on either historical earth or on randomly generated worlds while racing against computer opponents to reach the top of the evolution chain, and gradually evolving the player's animals to reach the "grand goal of intelligent life". It was published by Interplay Entertainment and Discovery Channel Multimedia in 1997.
Gameplay
Players select different ages to play through, including the Labyrinthodontia, or the first amphibians through to the evolution of the Age of Mammals. Each species has points that players can spend on adapting or evolving their creature populations, which are represented by animated icons of that creature. The more points a player spends on a field for a species, the quicker it evolves, becomes better at feeding (and growing in number faster), or better at fighting off predators. When a player evolves a creature, one can pick a population to be upgraded to the evolution one chooses. Each creature has a different set of evolution paths, and some can evolve into six or more different creatures. The world grows as the game advances, with land masses drifting and terrain shifting. As the player evolves the selected creatures, the player slowly advances in the complexity of the animals, eventually reaching intelligent life. Usually, the first player to do this is the victor (standard rules).
The game starts from basal tetrapods, the very first land dwellers: amphibians. At the gain of the game, each player starts with one population of a species of prehistoric amphibian—e.g. Ichthyostega, Tulerpeton, and Acanthostega. Gradually, if the player monitors the species' progress and moves them to more appropriate habitats and climate zones, the selected species will feed, breed, and prosper. From that secure population who can then evolve more advanced and adaptable creatu |
https://en.wikipedia.org/wiki/Self-tuning | In control theory a self-tuning system is capable of optimizing its own internal running parameters in order to maximize or minimize the fulfilment of an objective function; typically the maximization of efficiency or error minimization.
Self-tuning and auto-tuning often refer to the same concept. Many software research groups consider auto-tuning the proper nomenclature.
Self-tuning systems typically exhibit non-linear adaptive control. Self-tuning systems have been a hallmark of the aerospace industry for decades, as this sort of feedback is necessary to generate optimal multi-variable control for non-linear processes. In the telecommunications industry, adaptive communications are often used to dynamically modify operational system parameters to maximize efficiency and robustness.
Examples
Examples of self-tuning systems in computing include:
TCP (Transmission Control Protocol)
Microsoft SQL Server (Newer implementations only)
FFTW (Fastest Fourier Transform in the West)
ATLAS (Automatically Tuned Linear Algebra Software)
libtune (Tunables library for Linux)
PhiPAC (Self Tuning Linear Algebra Software for RISC)
MILEPOST GCC (Machine learning based self-tuning compiler)
Performance benefits can be substantial. Professor Jack Dongarra, an American computer scientist, claims self-tuning boosts performance, often on the order of 300%.
Digital self-tuning controllers are an example of self-tuning systems at the hardware level.
Architecture
Self-tuning systems are typically composed of four components: expectations, measurement, analysis, and actions. The expectations describe how the system should behave given exogenous conditions.
Measurements gather data about the conditions and behaviour. Analysis helps determine whether the expectations are being met- and which subsequent actions should be performed. Common actions are gathering more data and performing dynamic reconfiguration of the system.
Self-tuning (self-adapting) systems of automatic control a |
https://en.wikipedia.org/wiki/Xobdo.org | Xobdo.org is the first online Assamese dictionary to become available online on 10 March 2006. As of 6 August 2011 the database of this dictionary contains 37013 words of Assamese language. This is a wiki, where anybody can contribute and edit words in the dictionary provided they have a substantial knowledge of the Assamese language. Moreover, the dictionary has the facility to categorize the words as per their origin, nature and locality. It also has the facility of incorporating encyclopedic entries. This website uses UNICODE fonts which ensures global visibility of Assamese fonts when users set their character encoding option to Unicode (UTF-8).
The dictionary is the brainchild of Bikram M Baruah, an Assamese petroleum engineer based in Abu Dhabi. Later many interested people specialized in different areas joined as the working force behind this dictionary.
In 2007 xobdo.org added multiple interfaces to include 17 more languages spoken in the North East India: Khasi, Dimasa, Bodo, Karbi, Nagamese, Garo, Ao, Mizo, Mishing, Tanii (Apatani), Monpa, Meitei-lon, Bishnupriya, Chakma, Kok-Borok, Kuki, and Tanchangya aimed at giving a multilingual edge to the dictionary. Currently XOBDO gives a platform for 27 languages of North-East India, along with English. However, the database for these languages is still substantially small.
Authorship and management
A group of volunteers are responsible for adding words at XOBDO database. As of now the website has two levels of volunteers: "contributors" and "editors". A contributor enters an English and its corresponding Assamese word to the temporary database. Afterwards an editor assigns a unique "idea ID" to the corresponding English and Assamese words and carries on other editing works, if required, to match the standards of XOBDO. After assigning the idea ID the words are added to the main database ready to be retrieved by a user.
Technical details
Initially xobdo.org employed Microsoft server tools and technologies. |
https://en.wikipedia.org/wiki/Dekatron | In electronics, a Dekatron (or Decatron, or generically three-phase gas counting tube or glow-transfer counting tube or cold cathode tube) is a gas-filled decade counting tube. Dekatrons were used in computers, calculators, and other counting-related products during the 1950s and 1960s. "Dekatron" was the brand name used by Ericsson Telephones Limited (ETL), of Beeston, Nottingham (not to be confused with the Swedish TelefonAB Ericsson of Stockholm) and has since become a generic trademark. The device was invented by John Reginald Acton, with the patent assigned to Ericsson.
The dekatron was useful for computing, calculating, and frequency-dividing purposes because one complete revolution of the neon dot in a dekatron usually means 10 pulses on the guide electrode(s), and a signal can be derived from one of the cathodes in a dekatron to send a pulse, possibly for another counting stage. Dekatrons usually have a maximum input frequency in the high kilohertz (kHz) range – 100 kHz is fast, 1 MHz is around the maximum possible. These frequencies are obtained in hydrogen-filled fast dekatrons. Dekatrons filled with inert gas are inherently more stable and have a longer life, but their counting frequency is limited to 10 kHz (1–2 kHz is more common).
Design and operation
Internal designs vary by the model and manufacturer, but generally, a dekatron has ten cathodes and one or two guide electrodes plus a common anode. The cathodes are arranged in a circle with a guide electrode (or two) between each cathode. When the guide electrode(s) is pulsed properly, the neon gas will activate near the guide pins and then "jump" to the next cathode. Pulsing the guide electrodes (negative going pulses) repeatedly will cause the neon dot to move from cathode to cathode.
Hydrogen dekatrons require high voltages ranging from 400 to 600 volts on the anode for proper operation; dekatrons with inert gas usually require ~350 volts. When a dekatron is first powered up, a glowing dot appea |
https://en.wikipedia.org/wiki/In-cell%20charge%20control | In-Cell Charge Control or I-C3 is a method for very rapid charging of a Nickel-metal hydride battery, patented by Rayovac. Batteries using this technology are commonly sold as "15-minute rechargeables".
The charge control consists of a pressure switch built into the cell, which disconnects the charging current when the internal cell pressure rises above a certain limit; usually to . This prevents overcharging and damage to the cell.
Sources
Battery charging |
https://en.wikipedia.org/wiki/Lyubomir%20Ivanov%20%28explorer%29 | Lyubomir Ivanov (, born 7 October 1952 in Sofia) is a Bulgarian scientist, non-governmental activist, and Antarctic explorer. He is a graduate of the St. Kliment Ohridski University of Sofia with M.S. degree in mathematics in 1977, earned his PhD from Sofia University in 1980 under the direction of Dimiter Skordev, with a dissertation titled Iterative Operative Spaces, and was the 1987 winner of Acad. Nikola Obreshkov Prize, the highest Bulgarian award in mathematics.
Academic and NGO work
Appointed head of the Department of Mathematical Logic at the Institute of Mathematics and Informatics, Bulgarian Academy of Sciences in 1990, Ivanov has since helped found the Atlantic Club of Bulgaria, in which he held the position of chairman from 2001 to 2009. In 1994 he founded the Manfred Wörner Foundation, an organisation dedicated to trans-atlantic co-operation. Member of the Streit Council Advisory Board, Washington, DC since 2006. Founding Chairman, Antarctic Place-names Commission since 1994. He authored the modern Bulgarian system for Romanization of Cyrillic alphabet, adopted also for official use both by UN, and by the US and UK.
In the course of his work for, among others, the Atlantic Club of Bulgaria, Ivanov has given interviews to various news outlets, at times espousing views that NATO must expand eastwards due to a deficit in its military capacity.
Political career
Ivanov was a member of the UDF Coordinating Council and took part in the 1990 Bulgarian Round Table Talks. He served as a Member of Parliament in Bulgaria (1990–1991), acting as Chairman of the Green Party parliamentary group, and co-authored the current Constitution of Bulgaria. He has also served as parliamentary secretary for the Bulgarian ministry of foreign affairs.
Antarctic expeditions
Ivanov has taken part in several Antarctic expeditions. In 2004, Ivanov went with Doychin Vasilev on the Tangra 2004 topographic expedition, noted by Discovery Channel, the Natural History Museum, the Roya |
https://en.wikipedia.org/wiki/Iron%20Mountain%20%28company%29 | Iron Mountain Inc. () is an American enterprise information management services company founded in 1951 and headquartered in Boston, Massachusetts. Its records management, information destruction, and data backup and recovery services are supplied to more than 220,000 customers in 58 countries throughout North America, Europe, Latin America, Africa, Asia, and Australia. As of 2020 over 94% of Fortune 1000 companies use Iron Mountain's services to store and manage their information in some capacity.
Iron Mountain is a component of the S&P 500 Index and a member of the FTSE4Good index.
History
Founding and early years (1951–1970)
The company was started by Herman Knaust, who had made his fortune growing and marketing mushrooms. He purchased a depleted iron ore mine and of land in Kingston, New York for $9,000 in 1936, needing more space to grow his product. By 1950, the mushroom market had shifted, and Knaust was looking for alternative uses for his mine, which he had named "Iron Mountain."
Knaust saw a business opportunity, amidst widespread Cold War fears, in protecting corporate information from nuclear attack and other disasters.
The company was originally founded in 1951 as Iron Mountain Atomic Storage Corporation; it opened its first underground "vaults" in 1951 and its first sales office in the Empire State Building, about south. Iron Mountain's first customer was East River Savings Bank, who brought microfilm copies of deposit records and duplicate signature cards in armored cars for storage in the mountain facility. In 1978, the company opened its first above-ground records-storage facility.
Middle years (1970–2000)
This first iteration of Iron Mountain was bankrupt by the early 1970s and was wholly acquired by Vincent J. Ryan through his holdings in Schooner Capital Corporation, Boston, Massachusetts. At the time, it consisted of the original facility in Livingston, New York and IMAR (Iron Mountain at Rosendale), a former limestone mine and mushr |
https://en.wikipedia.org/wiki/Thiomer | Thiolated polymers designated thiomers are functional polymers used in biotechnology product development with the intention to prolong mucosal drug residence time and to enhance absorption of drugs. The name thiomer was coined by Andreas Bernkop-Schnürch in 2000. Thiomers have thiol bearing side chains. Sulfhydryl ligands of low molecular mass are covalently bound to a polymeric backbone consisting of mainly biodegradable polymers, such as chitosan, hyaluronic acid, cellulose derivatives, pullulan, starch, gelatin, polyacrylates, cyclodextrins, or silicones.
Thiomers exhibit properties potentially useful for non-invasive drug delivery via oral, ocular, nasal, vesical, buccal and vaginal routes. Thiomers show also potential in the field of tissue engineering and regenerative medicine. Various thiomers such as thiolated chitosan and thiolated hyaluronic acid are commercialy available as scaffold materials. Thiomers can be directly compressed to tablets or given as solutions. In 2012, a second generation of thiomers – called "preactivated" or "S-protected" thiomers – were introduced.
In contrast to thiomers of the first generation, preactivated thiomers are stable towards oxidation and display comparatively higher mucoadhesive and permeation enhancing properties. Approved thiomer products for human use are for example eyedrops for treatment of dry eye syndrome or adhesive gels for treatment of nickel allergy.
Properties and applications
Mucoadhesion
Thiomers are capable of forming disulfide bonds with cysteine substructures of the mucus gel layer covering mucosal membranes. Because of this property they exhibit up to 100-fold higher mucoadhesive properties in comparison to the corresponding unthiolated polymers. Because of their mucoadhesive properties, thiolated polymers are an effective tool in the treatment of diseases such as dry eye, dry mouth, and dry vagina syndrome where dry mucosal surfaces are involved.
In situ gelation
Various polymers such as polox |
https://en.wikipedia.org/wiki/Minimax%20eversion | In geometry, minimax eversions are a class of sphere eversions, constructed by using half-way models.
It is a variational method, and consists of special homotopies (they are shortest paths with respect to Willmore energy); contrast with Thurston's corrugations, which are generic.
The original method of half-way models was not optimal: the regular homotopies passed through the midway models, but the path from the round sphere to the midway model was constructed by hand, and was not gradient ascent/descent.
Eversions via half-way models are called tobacco-pouch eversions by Francis and Morin.
Half-way models
A half-way model is an immersion of the sphere in , which is so-called because it is the half-way point of a sphere eversion. This class of eversions has time symmetry: the first half of the regular homotopy goes from the standard round sphere to the half-way model, and the second half (which goes from the half-way model to the inside-out sphere) is the same process in reverse.
Explanation
Rob Kusner proposed optimal eversions using the Willmore energy on the space of all immersions of the sphere in .
The round sphere and the inside-out round sphere are the unique global minima for Willmore energy, and a minimax eversion is a path connecting these by passing over a saddle point (like traveling between two valleys via a mountain pass).
Kusner's half-way models are saddle points for Willmore energy, arising (according to a theorem of Bryant) from certain complete minimal surfaces in 3-space; the minimax eversions consist of gradient ascent from the round sphere to the half-way model, then gradient descent down (gradient descent for Willmore energy is called Willmore flow). More symmetrically, start at the half-way model; push in one direction and follow Willmore flow down to a round sphere; push in the opposite direction and follow Willmore flow down to the inside-out round sphere.
There are two families of half-way models (this observation is due to Fr |
https://en.wikipedia.org/wiki/Segmentation%20gene | A segmentation gene is a gene involved in the early stages of pattern formation that define repeated units (metameres) in a segmented organism, usually the embryo. They are classified into 3 groups: gap genes, pair-rule genes, and segment polarity genes. The expression of gap genes result in the formation of gaps in the normal pattern of structure in the embryo. Expression of pair-rule genes subdivides the embryo into a series of stripes and sets the boundaries of the parasegments. Segment polarity genes define the anterior and posterior polarities within each embryonic parasegment. |
https://en.wikipedia.org/wiki/International%20Conference%20on%20Electronic%20Properties%20of%20Two-Dimensional%20Systems | The International Conference on Electronic Properties of Two-Dimensional Systems (EP2DS), is a biannual event, where over hundred scientists meet for the presentation of new developments on the special field of two-dimensional electron systems in semiconductors. Most transistors in integrated circuits have such a two-dimensional electron system inside, but also the quantum Hall effect was discovered in such a structure.
The conference series started 1975 at the Brown University in Providence, Rhode Island, United States. The next in the series will be held July 31-August 4, 2017 at Penn State.
Conference list
EP2DS-1 - Brown University, Providence, Rhode Island, USA (1975)
EP2DS-2 - Berchtesgaden, Germany (1977)
...
EP2DS-10 - Newport, Rhode Island, USA (1993)
EP2DS-11 - Nottingham, England (1995)
EP2DS-12 - Tokyo, Japan (1997)
EP2DS-13 - Ottawa, Canada (1999)
EP2DS-14 - Prague, Czech (2001)
EP2DS-15 - Nara, Japan (2003)
EP2DS-16 - Albuquerque, New Mexico, USA (2005)
EP2DS-17 - Genova, Italy (2007)
EP2DS-18 - Kobe, Japan (2009)
EP2DS 19 - Tallahassee, Florida, USA (2011)
EP2DS 20 - Wrocław, Poland (2013)
EP2DS-21 - Sendai, Japan (2015)
EP2DS-22 - State College, Pennsylvania, USA (2017)
Physics conferences |
https://en.wikipedia.org/wiki/End%20System%20Multicast | End System Multicast (ESM) was a research project at Carnegie Mellon University. It developed a peercasting system for streaming live, high-quality video and audio to large audiences.
History
The project was founded in 1999. It was used to broadcast events online over the internet, including:
SIGCOMM 2002 and 2003, NOSSDAV 2004 and INFOCOM 2005
John Kerry's rally at CMU in 2004
cmuTV
DARPA Grand Challenge in 2004
RoboCup 2005
ESM was featured at the Intel Developer Forum in 2005.
ESM is no longer under active development by researchers at CMU. In 2006, several members of the ESM research group founded Rinera Networks in order to commercialize the ESM technology. In 2008, Rinera Networks changed its name to Conviva.
Technology
ESM used a peer-to-peer network to distribute video data across all viewers of a video stream. It constructs an overlay tree to distribute data, and continuously optimizes this tree to minimize end-to-end latency. The root of the tree is the source of the broadcast. This is typically the machine that encodes the video data. This machine sends a stream of data packets to the nodes at the first level of the tree. Each of those nodes then forwards the data to the nodes connected to them, and so on, such that all nodes in the system receive the data stream.
ESM allowed any user with a DSL or broadband connection or higher to broadcast good quality video to a large number of people. Since it is a peer to peer network, a broadcaster need only broadcast the video to one person for any number of people to view it.
Due to the nature of peer to peer multimedia networks, skips in playback or buffering can occur. |
https://en.wikipedia.org/wiki/Isovaleryl-CoA | Isovaleryl-coenzyme A, also known as isovaleryl-CoA, is an intermediate in the metabolism of branched-chain amino acids.
Leucine metabolism
See also
Isovaleryl coenzyme A dehydrogenase |
https://en.wikipedia.org/wiki/Methylcrotonyl-CoA | 3-Methylcrotonyl-CoA (β-Methylcrotonyl-CoA or MC-CoA) is an intermediate in the metabolism of leucine.
It is found in mitochondria, where it is formed from isovaleryl-coenzyme A by isovaleryl coenzyme A dehydrogenase. It then reacts with CO2 to yield 3-Methylcrotonyl-CoA carboxylase.
Leucine metabolism
See also
Methylcrotonyl-CoA carboxylase |
https://en.wikipedia.org/wiki/3-Methylglutaconyl-CoA | 3-Methylglutaconyl-CoA (MG-CoA), also known as β-methylglutaconyl-CoA, is an intermediate in the metabolism of leucine. It is metabolized into HMG-CoA.
Leucine metabolism
See also
Methylcrotonyl-CoA carboxylase
Methylglutaconyl-CoA hydratase |
https://en.wikipedia.org/wiki/Sainsbury%20Laboratory | The Sainsbury Laboratory (TSL) is a research institute located at the Norwich Research Park in Norwich, Norfolk, England, that carries out fundamental biological research and technology development on aspects of plant disease, plant disease resistance and microbial symbiosis in plants.
History
In 1987, an agreement was signed to establish The Sainsbury Laboratory. This agreement made the laboratory a joint venture between several organizations, including the Gatsby Charitable Foundation, the John Innes Foundation, the University of East Anglia, and the Agricultural and Food Research Council (now BBSRC).
Later that year, the laboratory employed its first members of staff. Then, in 1989, The Sainsbury Laboratory moved into its current building. This building was constructed alongside the John Innes Centre on the Norwich Research Park.
Research
The Sainsbury Laboratory conducts research on various topics related to plant-microbe interactions.
The laboratory investigates innate immune recognition in plants and the signaling and cellular changes that occur during plant-microbe interactions. Additionally, researchers at the laboratory study plant and pathogen genomics to gain a better understanding of the mechanisms involved in plant-microbe interactions.
One of the key areas of research is the identification and study of plant disease resistance genes. Another important research area is the biology of pathogen effector proteins, which play a crucial role in the interaction between plants and pathogens.
With this knowledge, the laboratory employs biotechnological approaches to develop crop disease resistance. These approaches are aimed at reducing agrochemical input and the percentage of crops lost to disease.
The Sainsbury Laboratory partners with the John Innes Centre on a Plant Health Institute Strategic Program (ISP) funded by the Biotechnology and Biological Sciences Research Council (BBSRC).
Training
The Sainsbury Laboratory provides a training environment |
https://en.wikipedia.org/wiki/Q%C4%81%E1%B8%8D%C4%AB%20Z%C4%81da%20al-R%C5%ABm%C4%AB | (1364 in Bursa, Ottoman Empire – 1436 in Samarqand, Timurid Empire), whose actual name was Salah al-Din Musa Pasha ( means "son of the judge", al-rūmī "the Roman" indicating he came from Asia Minor, which was once Roman), was a Turkish astronomer and mathematician who worked at the observatory in Samarkand. He computed sin 1° to an accuracy of 10−12.
Together with Ulugh Beg, al-Kāshī and a few other astronomers, Qāḍī Zāda produced the Zij-i-Sultani, the first comprehensive stellar catalogue since the Maragheh observatory's Zij-i Ilkhani two centuries earlier. The Zij-i Sultani contained the positions of 992 stars.
His works
Sharh al-Mulakhkhas (Commentary on Jaghmini's compendium on the science of Astronomy)
Sharh Ashkal al-Ta'sis (Commentary on Samarkandi's Arithmetics)
Further reading
External links
(PDF version)
1364 births
1436 deaths
14th-century mathematicians
15th-century mathematicians
Mathematicians of the medieval Islamic world
15th-century astronomers
Transoxanian Islamic scholars
Medieval geometers
Scientists from the Ottoman Empire |
https://en.wikipedia.org/wiki/Sorbus%20americana | The tree species Sorbus americana is commonly known as the American mountain-ash. It is a deciduous perennial tree, native to eastern North America.
The American mountain-ash and related species (most often the European mountain-ash, Sorbus aucuparia) are also referred to as rowan trees.
Description
Sorbus americana is a relatively small tree, reaching in height. The American mountain-ash attains its largest specimens on the northern shores of Lake Huron and Lake Superior.
It resembles the European mountain-ash, Sorbus aucuparia.
Bark Light gray, smooth, surface scaly. Branchlets downy at first, later become smooth, brown tinged with red, lenticular, finally they become darker and the papery outer layer becomes easily separable.
Wood Pale brown; light, soft, close-grained but weak. Specific gravity, 0.5451; weight of cu. ft., 33.97 lbs.
Winter budsDark red, acute, one-fourth to three-quarters of an inch long. Inner scales are very tomentose and enlarge with the growing shoot.
Leaves Alternate, compound, odd-pinnate, long, with slender, grooved, dark green or red petiole. Leaflets 13 to 17, lanceolate or long oval, two to three inches long, one-half to two-thirds broad, unequally wedge-shaped or rounded at base, serrate, acuminate, sessile, the terminal one sometimes borne on a stalk half an inch long, feather-veined, midrib prominent beneath, grooved above. They come out of the bud downy, conduplicate; when full grown are smooth, dark yellow green above and paler beneath. In autumn they turn a clear yellow. Stipules leaf-like, caducous.
FlowersMay, June, after the leaves are full grown. Perfect, white, one-eighth of an inch across, borne in flat compound cymes three or four inches across. Bracts and bractlets acute, minute, caducous.
Calyx Urn-shaped, hairy, five-lobed; lobes, short, acute, imbricate in bud.
Corolla Petals five, creamy white, orbicular, contracted into short claws, inserted on calyx, imbricate in bud.
Stamens Twenty to thirty, inserte |
https://en.wikipedia.org/wiki/Glutaryl-CoA | Glutaryl-coenzyme A is an intermediate in the metabolism of lysine and tryptophan.
See also
Glutaryl-CoA dehydrogenase |
https://en.wikipedia.org/wiki/Carousel%20feeding | Carousel feeding is a cooperative hunting method used by Norwegian orcas (Orcinus orca) to capture wintering Norwegian spring-spawning herring (Clupea harengus). The term carousel feeding was first used to describe a similar hunting behaviour in bottlenose dolphins (Turslops truncatus) in the Black Sea. There are two main phases of carousel feeding in orcas, the herding phase and the feeding phase. In the herding phase the orcas surround a school of herring and herd them into a tight ball. They tighten the ball by blowing bubbles, flashing their white underside and slapping their tails on the surface. They move the ball of herring toward the surface of the water before initiating the feeding phase. During the feeding phase several orcas begin to eat while the others continue herding the fish to maintain the ball. The feeding orcas whip their tails into the ball to stun and kill several herring at a time. The dead and stunned herring are then consumed and their heads and spines discarded.
Herding
Carousel feeding begins when an orca pod locates a school of herring. This is primarily done by echolocation. Orcas can detect herring at a much greater distance than the herring can detect the predator. This gives the orcas an advantage over the herring. The matriarch orca leads the pod (group of 3–9 orcas) in splitting the herring school into a smaller more manageable group. The orcas then circle the herring forcing them into a ball shape. The diameter of the tight ball can range anywhere between two and seven meters. During this period the orcas are highly vocal including clicks and whistling. While tightening the herring ball the orcas push their prey towards the surface of the water. It has been speculated that surface feeding is beneficial because the animals do not have to deep dive so energy is saved, and since the pressure is less intense each tail strike is more effective. In addition, the light conditions are better so the orcas can be more accurate, and the sea |
https://en.wikipedia.org/wiki/Crotonyl-CoA | Crotonyl-coenzyme A is an intermediate in the fermentation of butyric acid, and in the metabolism of lysine and tryptophan. It is important in the metabolism of fatty acids and amino acids.
Crotonyl-coA and reductases
Before a 2007 report by Alber and coworkers, crotonyl-coA carboxylases and reductases (CCRs) were known for reducing crotonyl-coA to butyryl-coA. A report by Alber and coworkers concluded that a specific CCR homolog was able to reduce crotonyl-coA to (2S)-ethyl malonyl-coA which was a favorable reaction. The specific CCR homolog came from the bacterium Rhodobacter sphaeroides.
Role of Crotonyl-coA in Transcription
Post-translational modification of histones either by acetylation or crotonylation is important for the active transcription of genes. Histone crotonylation is regulated by the concentration of crotonyl-coA which can change based on environmental cell conditions or genetic factors. |
https://en.wikipedia.org/wiki/%CE%92-Hydroxybutyryl-CoA | β-Hydroxybutyryl-CoA (or 3-hydroxybutyryl-coenzyme A) is an intermediate in the fermentation of butyric acid, and in the metabolism of lysine and tryptophan. The L-3-hydroxybutyl-CoA (or (S)-3-hydroxybutanoyl-CoA) enantiomer is also the second to last intermediate in beta oxidation of even-numbered, straight chain, and saturated fatty acids.
See also
Crotonyl-coenzyme A
Acetoacetyl CoA
Beta-hydroxybutyryl-CoA dehydrogenase |
https://en.wikipedia.org/wiki/Crotonase%20family | The crotonase family comprises mechanistically diverse proteins that share a conserved trimeric quaternary structure (sometimes a hexamer consisting of a dimer of trimers), the core of which consists of 4 turns of a (beta/beta/alpha)n superhelix.
Some enzymes in the superfamily have been shown to display dehalogenase, hydratase, and isomerase activities, while others have been implicated in carbon-carbon bond formation and cleavage as well as the hydrolysis of thioesters. However, these different enzymes share the need to stabilize an enolate anion intermediate derived from an acyl-CoA substrate. This is accomplished by two structurally conserved peptidic NH groups that provide hydrogen bonds to the carbonyl moieties of the acyl-CoA substrates and form an "oxyanion hole". The CoA thioester derivatives bind in a characteristic hooked shape and a conserved tunnel binds the pantetheine group of CoA, which links the 3'-phosphate ADP binding site to the site of reaction. Enzymes in the crotonase superfamily include:
Enoyl-CoA hydratase (crotonase; ), which catalyses the hydratation of 2-trans-enoyl-CoA into 3-hydroxyacyl-CoA.
3-2trans-enoyl-CoA isomerase (or dodecenoyl-CoA isomerise; ), which shifts the 3-double bond of the intermediates of unsaturated fatty acid oxidation to the 2-trans position.
3-hydroxybutyryl-CoA dehydrogenase (crotonase; ), a bacterial enzyme involved in the butyrate/butanol-producing pathway.
4-Chlorobenzoyl-CoA dehalogenase (), a Pseudomonas enzyme which catalyses the conversion of 4-chlorobenzoate-CoA to 4-hydroxybenzoate-CoA.
Dienoyl-CoA isomerase, which catalyses the isomerisation of 3-trans,5-cis-dienoyl-CoA to 2-trans,4-trans-dienoyl-CoA.
Naphthoate synthase (MenB, or DHNA synthetase; ), a bacterial enzyme involved in the biosynthesis of menaquinone (vitamin K2).
Carnitine racemase (gene caiD), which catalyses the reversible conversion of crotonobetaine to L-carnitine in Escherichia coli.
Methylmalonyl CoA decarboxylase (MMCD; ), |
https://en.wikipedia.org/wiki/Formiminoglutamic%20acid | Formiminoglutamic acid (FIGLU; conjugate base, formiminoglutamate) is an intermediate in the catabolism of L-histidine to L-glutamic acid. It thus is also a biomarker for intracellular levels of folate. The FIGLU test is used to identify vitamin B₁₂ deficiency, folate deficiency, and liver failure or liver disease. It is elevated with folate trapping, where it is accompanied by decreased methylmalonic acid, increased folate and a decrease in homocysteine.
See also
Formiminotransferase cyclodeaminase
Glutamate-1-semialdehyde
Glutamic acid
Imidazol-4-one-5-propionic acid |
https://en.wikipedia.org/wiki/GLS2 | Glutaminase 2 (liver, mitochondrial) is a protein that in humans is encoded by the GLS2 gene.
Structure
The GLS2 gene is on the 12th chromosome in humans, with its specific location being 12q13.3. It contains 19 exons.
Function
GLS2 is a part of the glutaminase family. The protein encoded by this gene is a mitochondrial phosphate-activated glutaminase that catalyzes the hydrolysis of glutamine to stoichiometric amounts of glutamate and ammonia. Originally thought to be liver-specific, this protein has been found in other tissues as well. Alternative splicing results in multiple transcript variants that encode different isoforms.
Clinical significance
GLS2 has interesting molecular relationships with tumor progression and cancer. Glutaminase 2 negatively regulates the PI3K/AKT signaling and shows tumor suppression activity in human hepatocellular carcinoma. Additionally, silencing of GLS and overexpression of GLS2 genes cooperate in decreasing the proliferation and viability of glioblastoma cells. |
https://en.wikipedia.org/wiki/5-Formiminotetrahydrofolate | 5-Formiminotetrahydrofolate is an intermediate in the catabolism of histidine. It is produced by glutamate formimidoyltransferase and then converted into 5,10-methenyltetrahydrofolate by formiminotransferase cyclodeaminase. |
https://en.wikipedia.org/wiki/Liquid%20paraffin%20%28drug%29 | Liquid paraffin, also known as paraffinum liquidum, paraffin oil, liquid paraffin oil or Russian mineral oil, is a very highly refined mineral oil used in cosmetics and medicine. Cosmetic or medicinal liquid paraffin should not be confused with the paraffin (i.e. kerosene) used as a fuel. The generic sense of paraffin meaning alkane led to regional differences for the meanings of both paraffin and paraffin oil. It is a transparent, colorless, nearly odorless, and oily liquid that is composed of saturated hydrocarbons derived from petroleum.
The term paraffinum perliquidum is sometimes used to denote light liquid paraffin, while the term paraffinum subliquidum is sometimes used to denote a thicker mineral oil.
History
Petroleum is said to have been used as a medicine since 400 BC, and has been mentioned in the texts of classical writers Herodotus, Plutarch, Dioscorides, Pliny, and others. It was used extensively by early Arabians and was important in early Indian medicine. Its first use internally is attributed to Robert A. Chesebrough, who patented it in 1872 for the manufacture of a "new and useful product from petroleum." After Sir W. Arbuthnot Lane, who was then Chief Surgeon of Guy's Hospital, recommended it as a treatment for intestinal stasis and chronic constipation in 1913, liquid paraffin gained more popularity.
Usage in medicine
Liquid paraffin is primarily used as a pediatric laxative in medicine and is a popular treatment for constipation and encopresis. Because of its ease of titration, the drug is convenient to synthesize. It acts primarily as a stool lubricant, and is thus not associated with abdominal cramps, diarrhea, flatulence, disturbances in electrolytes, or tolerance over long periods of usage, side effects that osmotic and stimulant laxatives often engender (however, some literature suggests that these may still occur). The drug acts by softening the feces and coats the intestine with an oily film. Because of this it reduces the pain caus |
https://en.wikipedia.org/wiki/Histamine%20N-methyltransferase | Histamine N-methyltransferase (HNMT, HMT) is an enzyme involved in the metabolism of histamine. It is one of two enzymes involved in the metabolism of histamine in mammals, the other being diamine oxidase (DAO). HNMT catalyzes the methylation of histamine in the presence of S-adenosylmethionine (SAM-e) forming N-methylhistamine. The HNMT enzyme is present in most body tissues but is not present in serum. Histamine N-methyltransferase is encoded by a single gene, HNMT, which in humans has been mapped to chromosome 2.
Function
The function of the HNMT enzyme is histamine metabolism by ways of Nτ-methylation using SAM-e as the methyl donor, producing N-methylhistamine, which, unless excreted, can be further processed by monoamine oxidase B (MAOB) or by DAO. Methylated histamine metabolites are excreted with urine.
In mammals, histamine is metabolized by two major pathways: oxidative deamination via DAO, encoded by the AOC1 gene, and Nτ-methylation via HNMT, encoded by the HNMT gene. In the brain of mammals histamine neurotransmitter activity is controlled by Nτ-methylation since DAO is not present in the central nervous system.
As about the biologic species, the HNMT enzyme is found in vertebrates, including birds, reptiles and amphibian, but not in invertebrates and plants.
The HNMT enzyme resides in the cytosol intracellular fluid. Whereas DAO metabolizes extracellular free histamine, be it either exogenous came with food or mostly endogenous released from granules of mast cells and basophils as a result of allergic reactions, since DAO is mainly expressed in the cells of intestinal epithelium, HNMT is involved in metabolism of the persistently present intracellular primarily endogenous histamine, mainly in kidneys and liver, but also in bronchi, large intestine, ovary, prostate, spinal cord, spleen, trachea and peripheral tissues. In the case of flawed HNMT activity, the organs which are most affected are brain, liver and mucous membrane of bronchus. Consequent |
https://en.wikipedia.org/wiki/Saccharopine%20dehydrogenase | In molecular biology, the protein domain Saccharopine dehydrogenase (SDH), also named Saccharopine reductase, is an enzyme involved in the metabolism of the amino acid lysine, via an intermediate substance called saccharopine. The Saccharopine dehydrogenase enzyme can be classified under , , , and . It has an important function in lysine metabolism and catalyses a reaction in the alpha-Aminoadipic acid pathway. This pathway is unique to fungal organisms therefore, this molecule could be useful in the search for new antibiotics. This protein family also includes saccharopine dehydrogenase and homospermidine synthase. It is found in prokaryotes, eukaryotes and archaea.
Function
Simplistically, SDH uses NAD+ as an oxidant to catalyse the reversible pyridine nucleotide dependent oxidative deamination of the substrate, Saccharopine, in order to form the products, lysine and alpha-ketoglutarate.
This can be described by the following equation:
SDH
Saccharopine ⇌ lysine + alpha-ketoglutarate
Saccharopine dehydrogenase EC catalyses the condensation to of l-alpha-aminoadipate-delta-semialdehyde (AASA) with l-glutamate to give an imine, which is reduced by NADPH to give saccharopine. In some organisms this enzyme is found as a bifunctional polypeptide with lysine ketoglutarate reductase (PF).
Homospermidine synthase proteins (EC). Homospermidine synthase (HSS) catalyses the synthesis of the polyamine homospermidine from 2 mol putrescine in an NAD+-dependent reaction.
Structure
There appears to be two protein domains of similar size. One domain is a Rossmann fold that binds NAD+/NADH, and the other is relatively similar. Both domains contain a six-stranded parallel beta-sheet surrounded by alpha-helices and loops (alpha/beta fold).
Clinical significance
Deficiencies are associated with hyperlysinemia. |
https://en.wikipedia.org/wiki/DevPartner | DevPartner is a set of software development and testing tools developed by NuMega, acquired by Compuware in 1997, which on June 1, 2009 sold it to Micro Focus. There are two versions: one for native and .NET Windows applications, and another for Java applications. It is currently sold by Micro Focus.
DevPartner Studio (DPS) is a suite of tools allowing a developer to analyze native (unmanaged) and .NET (managed) code for:
Code quality and complexity
Memory leak detection
Memory optimization
Performance analysis (timing)
Performance expert (CPU, disk and network resource usage)
Code coverage analysis
Fault simulation (both .NET and environmental)
Error detection and interop monitoring for C/C++ using BoundsChecker technology.
Each analysis can be configured to show detail at the method or line level.
DevPartner Studio integrates with all versions of Microsoft Visual Studio from 2005 through 2019, providing toolbar buttons and menu options to access all of the tools. All of the tools can also be run from the command line allowing for automation and continuous integrated testing processes to be set up.
DevPartner Java Edition (DPJ) integrates a set of functionality enabling developers to analyze Java code for
Code quality and complexity
Memory leak detection
Memory profiling and optimization.
Performance profiling and optimization.
Thread analysis and dead-lock detection.
Code coverage analysis.
DPJ can show the call graph when troubleshooting an issue, and it can dig into details at the method and line level.
DPJ integrates with Eclipse 3.2/3.3, OptimalJ, JBuilder, and IBM RAD 6.0 providing menus and tools to access all its functionality. All of the tools can also be run from the command line as well, which enables the possibility of automation and continuous integration.
See also
BoundsChecker
Fault Simulator |
https://en.wikipedia.org/wiki/Asparagine%20synthetase | Asparagine synthetase (or aspartate-ammonia ligase) is a chiefly cytoplasmic enzyme that generates asparagine from aspartate. This amidation reaction is similar to that promoted by glutamine synthetase. The enzyme is ubiquitous in its distribution in mammalian organs, but basal expression is relatively low in tissues other than the exocrine pancreas.
Above average presence of asparagine synthetase in certain leukemia strains has been linked to be a significant contributing factor of chemotherapy resistance, particularly to the chemotherapy drug, L-asparaginase.
Structure
Escherichia coli derived asparagine synthetase is a dimeric protein with each subunit folding into two distinct domains. The N-terminal region consists of two layers of six-stranded antiparallel β-sheets between which is the active site responsible for the hydrolysis of glutamine. The C-terminal domain consists of a five-stranded parallel β-sheet flanked on either side by α-helices. This domain is responsible for the binding of both Mg2+ATP and aspartate. These two active sites are connected by a tunnel lined primarily with backbone atoms and hydrophobic, nonpolar amino acid residues.
Structural characterization of asparagine synthetase from mammalian sources have been difficult due to the low abundance and instability of the enzyme during purification procedures.
Mechanism
Using information from Escherichia coli derived asparagine synthetase, some basic mechanisms of the enzyme have been understood. The N-terminal active site catalyzes glutamine hydrolysis to yield glutamate and ammonia. The C-terminal active site catalyzes activation of the side-chain carboxylate of aspartate to form an electrophilic intermediate, β-aspartyl-AMP (βAspAMP) 1, and inorganic pyrophosphate (PPi). The tunnel that links the two active sites allows for the passage of an ammonia molecule to act as a common intermediate to couple the two half-reactions carried out in the independent active sites of the enzyme. Thus |
https://en.wikipedia.org/wiki/National%20Science%20Advisory%20Board%20for%20Biosecurity | The National Science Advisory Board for Biosecurity (NSABB) is a panel of experts that reports to the Secretary of the United States Department of Health and Human Services. It is tasked with recommending policies on such questions as how to prevent published research in biotechnology from aiding terrorism, without slowing scientific progress.
The NSABB is a federal advisory committee that addresses issues related to biosecurity and dual use research at the request of the United States Government. The NSABB has up to 25 voting members with a broad range of expertise including molecular biology, microbiology, infectious diseases, biosafety, public health, veterinary medicine, plant health, national security, biodefense, law enforcement, scientific publishing, and other related fields.
History
In May 2016, the NSABB published "RECOMMENDATIONS FOR THE EVALUATION AND OVERSIGHT OF PROPOSED GAIN-OF-FUNCTION RESEARCH".
Publications
The NSABB had published 11 reports as of February 2021. The first report on the list was released in December 2006.
Composition
The NSABB is composed of non-voting ex officio and appointed voting members. As of 2021, the Chair of the NSABB was Gerald W. Parker, Jr., DVM, PhD.
As of 2017, the ex officio members were:
Department of Commerce:
Jason Boehm, Ph.D., Office of Program Analysis and Evaluation, National Institute of Standards and Technology Division Head
Department of Defense :
David Christian Hassell, Ph.D., Deputy Assistant Secretary of Defense for Nuclear and Chemical and Biological Programs
Department of Energy:
Sharlene Weatherwax, Ph.D., Associate Director of Science for Biological and Environmental Research
Department of Health and Human Services
Anthony S. Fauci, M.D., Director, National Institute of Allergy & Infectious Disease
Sally Phillips, R.N., Ph.D., Deputy Assistant Secretary, Office of Policy and Planning, Office of the Assistant Secretary for Preparedness and Response
CAPT Carmen Maher, Deputy Direct |
https://en.wikipedia.org/wiki/Charles%20H.%20Smith%20%28historian%29 | Charles H. Smith (born September 30, 1950) is Professor Emeritus at Western Kentucky University (WKU). He is best known for his work as a biogeographer, historian/philosopher and bibliographer of science, especially for his expertise on the career of Alfred Russel Wallace.
Smith was born in Winsted, Connecticut, and grew up in the nearby town of New Hartford. Since his undergraduate college years he has lived in Georgia, Connecticut, Indiana, Illinois, Australia, Pennsylvania, and, from 1995, Bowling Green, Kentucky.
He created and maintains the website The Alfred Russel Wallace Page hosted by WKU and devoted to Wallace scholarship, which includes a comprehensive bibliography of Wallace's publications and interviews, texts of Wallace's works, and writings on Wallace by Smith and others. Smith has also produced a number of conventional writings on Wallace including the anthology Alfred Russel Wallace: An Anthology of His Shorter Writings published in 1991, a three-volume collection Alfred Russel Wallace: Writings on Evolution, 1843–1912 published in 2004, an edited collection of writings Natural Selection and Beyond: The Intellectual Legacy of Alfred Russel Wallace published in 2008, Alfred Russel Wallace's 1886–1887 Travel Diary: The North American Lecture Tour published in 2013, Enquête sur un Aventurier de l'Esprit: Le Véritable Alfred Russel Wallace (translated by Antoine Guillemain) published in 2013, Dear Sir: Sixty-Nine Years of Alfred Russel Wallace Letters to the Editor published in 2014, An Alfred Russel Wallace Companion published in 2019, and about seventy journal articles, including many in the series Alfred Russel Wallace Notes (of which he is the Editor).
Smith was originally trained as a biogeographer and has produced written work in that and cognate fields, including the bibliographic compilation Biodiversity Studies: A Bibliographic Review published in 2000, and journal-based philosophical, historical and empirical studies; he additionally hosts |
https://en.wikipedia.org/wiki/Airport%20reference%20temperature | Aerodrome reference temperature is defined by ICAO (Convention on International Civil Aviation, Annex 14, Vol. I, 2.4.1) as the monthly mean of the daily maximum temperatures for the hottest month of the year (the hottest month being that which has the highest monthly mean temperature). This temperature should be averaged over a period of years. |
https://en.wikipedia.org/wiki/Spatial%20twist%20continuum | In finite element analysis, the spatial twist continuum (STC) is a dual representation of a hexahedral mesh that defines the global connectivity constraint. Generation of an STC can simplify the automated generation of a mesh. The method was published in 1993 by a group led by Peter Murdoch.
The name is derived from the description of the surfaces that define the connectivity of the hexahedral elements. The surfaces are arranged in the three principal dimensions such that they form orthogonal intersections that coincide with the centroid of the hexahedral element. They are arranged predominately coplanar to each other in their respective dimensions yet they can twist into the other dimensional planes through transitions. The surfaces are unbroken throughout the entire volume of the mesh hence they are continuums.
Explanation
One of the areas where the STC finds application is computational fluid dynamics, a field of analysis that involves simulating the flow of fluids over and through bodies defined by boundary surfaces. The procedure involves building a mesh using it to analyze the system using a finite volume approach.
An analyst has many choices available for creating a mesh that can be used in a CFD or CAE simulation, one is to use a Tetrahedral, Polyhedral, Trimmed Cartesian or Mixed of Hybrid of Hexahedra called hex dominate, these are classified as non-structured meshes, which can all be created automatically, however the CFD and FEA results are both inaccurate and prone to solution divergence, (the simulation fails to solve).
The other option for the analyst is to use an all-hexahedral mesh that offers far greater solver stability and speed as well as accuracy and the ability to run much more powerful turbulence solvers like Large eddy simulation LES in transient mode as opposed to the non-structured meshes that can only run a steady state RANS model.
The difficulty with generating an all-hexahedral mesh on a complex geometry is that mesh needs to ta |
https://en.wikipedia.org/wiki/It%20Never%20Rains%20in%20Southern%20California | "It Never Rains in Southern California" is a 1972 song jointly written and composed by Albert Hammond and Mike Hazlewood and sung by Hammond, a British-born singer-songwriter.
Lyrics content
The lyrics of "It Never Rains In Southern California" tell a first-person story of a showbiz aspirant whose attempts to break into entertainment were failures, but who wants to hide that fact from those he had left behind to pursue his dreams.
Though Hammond's and Hazlewood's lyrics do not actually specify the narrator's living conditions, it can be inferred that he was found homeless and penniless, a humiliation he would naturally be unwilling to reveal to those he had left behind.
Recording
Hammond collaborated with Don Altfeld to produce the selection when he recorded it.
Instrumental backing was provided by L.A. session musicians from the Wrecking Crew. The song appears on Hammond's debut album of the same name and peaked at number five on the US Billboard Hot 100 chart. It is Hammond's only top 10 hit to date (although he would have one other top 40 hit in 1974 with "I'm a Train").
In 1989, Hammond re-recorded the song for his Best of Me greatest hits compilation.
Chart performance
Weekly charts
Albert Hammond version
Year-end charts
Saori Minami version
Trent Summar and the New Row Mob version |
https://en.wikipedia.org/wiki/Coster%E2%80%93Kronig%20transition | The Coster–Kronig transition is a special case of the Auger process in which the vacancy is filled by an electron from a higher subshell of the same shell. If, in addition, the electron emitted (the "Auger electron") also belongs to the same shell, one calls this a super Coster–Kronig transition.
The Coster–Kronig process is named after the physicists Dirk Coster and Ralph Kronig. |
https://en.wikipedia.org/wiki/Video%20denoising | Video denoising is the process of removing noise from a video signal. Video denoising methods can be divided into:
Spatial video denoising methods, where image noise reduction is applied to each frame individually.
Temporal video denoising methods, where noise between frames is reduced. Motion compensation may be used to avoid ghosting artifacts when blending together pixels from several frames.
Spatial-temporal video denoising methods use a combination of spatial and temporal denoising. This is often referred to as 3D denoising.
It is done in two areas:
They are chroma and luminance, chroma noise is where one see color fluctuations and luminance is where one see light/dark fluctuations. Generally, the luminance noise looks more like film grain while chroma noise looks more unnatural or digital like.
Video denoising methods are designed and tuned for specific types of noise.
Typical video noise types are following:
Analog noise
Radio channel artifacts
High frequency interference (dots, short horizontal color lines, etc.)
Brightness and color channel interference (problems with antenna)
Video reduplication – false contouring appearance
VHS artifacts
Color-specific degradation
Brightness and color channel interference (specific type for VHS)
Chaotic line shift at the end of frame (lines resync signal misalignment)
Wide horizontal noise strips (old VHS or obstruction of magnetic heads)
Film artifacts (see also Film preservation)
Dust, dirt, spray
Scratches
Curling (emulsion exfoliation)
Fingerprints
Digital noise
Blocking – low bitrate artifacts
Ringing – low and medium bitrates artifact especially on animated cartoons
Blocks (slices) damage in case of losses in digital transmission channel or disk injury (scratches on DVD)
Different suppression methods are used to remove all these artifacts from video.
See also
Image denoising |
https://en.wikipedia.org/wiki/Chemical%20probe | In the field of chemical biology, a chemical probe is a small molecule that is used to study and manipulate a biological system such as a cell or an organism by reversibly binding to and altering the function of a biological target (most commonly a protein) within that system. Probes ideally have a high affinity and binding selectivity for one protein target as well as high efficacy. By changing the phenotype of the cell, a molecular probe can be used to determine the function of the protein with which it interacts.
See also
Chemical Probes Portal |
https://en.wikipedia.org/wiki/LCP%20theory | In chemistry, ligand close packing theory (LCP theory), sometimes called the ligand close packing model describes how ligand – ligand repulsions affect the geometry around a central atom. It has been developed by R. J. Gillespie and others from 1997 onwards and is said to sit alongside VSEPR which was originally developed by R. J. Gillespie and R Nyholm. The inter-ligand distances in a wide range of molecules have been determined. The example below shows a series of related molecules:
The consistency of the interligand distances (F-F and O-F) in the above molecules is striking and this phenomenon is repeated across a wide range of molecules and forms the basis for LCP theory.
Ligand radius
From a study of known structural data a series of inter-ligand distances has been determined and it has been found that there is a constant inter-ligand radius for a given central atom. The table below shows the inter-ligand radius (pm) for some of the period 2 elements:
The ligand radius should not be confused with the ionic radius.
Treatment of lone pairs
In LCP theory a lone pair is treated as a ligand. Gillespie terms the lone pair a lone pair domain and states that these lone pair domains push the ligands together until they reach the interligand distance predicted by the relevant inter-ligand radii. An example demonstrating this is shown below, where the F-F distance is the same in the AF3 and AF4+ species :
LCP and VSEPR
LCP and VSEPR make very similar predictions as to geometry but LCP theory has the advantage that predictions are more quantitative particularly for the second period elements, Be, B, C, N, O, F. Ligand -ligand repulsions are important when
the central atom is small e.g. period 2, (Be, B, C, N, O)
the ligands are only weakly electronegative compared to the central atom
the ligands are large compared to the central atom
there are 5 or more ligands around the central atom |
https://en.wikipedia.org/wiki/High%20Altitude%20Observatory | The High Altitude Observatory (HAO) conducts research and provides support and facilities for the solar-terrestrial physics research community in the areas of solar and heliospheric physics, and the effects of solar variability on the Earth's magnetosphere, ionosphere, and upper atmosphere.
HAO is a laboratory of the National Center for Atmospheric Research (NCAR). NCAR is managed by the University Corporation for Atmospheric Research (UCAR), and receives substantial funding from the National Science Foundation (NSF).
Mission and vision
HAO's mission is to understand the behavior of the Sun and its impact on the Earth, to support, enhance, and extend the capabilities of the university community and the broader scientific community, nationally and internationally, and to foster the transfer of knowledge and technology. As articulated in its Strategic Plan for 2011–2015, HAO's vision is to: Perform world-leading science to understand fundamentally and with predictive capability the sources and nature of solar and geospace variability; Provide scientific leadership and facilities to serve the wider community in common pursuit of these science objectives, and both support and benefit from the NCAR community; Support the education and training of early-career researchers in solar-terrestrial physics and instrumentation; and Provide advocacy for solar-terrestrial physics, promoting its results, and articulating its societal importance, to the rest of NCAR, the NSF, the university community, and the public.
HAO's telescopes are located at its Mauna Loa Solar Observatory, near the summit of that volcano on the big island of Hawaii. NCAR's solar observatory shares space on the campus of NOAA's larger Mauna Loa Observatory. HAO's researchers are based at NCAR headquarters, in Boulder, Colorado.
Eclipse expeditions
1952 - Khartoum, Sudan
This was a joint HAO – Naval Research Laboratory expedition, which obtained 50 spectra of the eclipse features of the sun.
1958 – |
https://en.wikipedia.org/wiki/Videcom%20International | Videcom International Limited is a United Kingdom travel technology company based in Henley-on-Thames. It designs, develops and provides modern computer reservations systems to airlines and the travel industry, specializing in the hosting and distribution of airline sales.
The system is connected to the Global Distribution Systems of Sabre, Amadeus, Galileo, Worldspan and Abacus, which travel agents use to make airline bookings, and is also connected to other airline systems for interline bookings. The IATA airline designator for Videcom is U1.
History
Founded in 1972, the company originally manufactured computer terminals for uses throughout the aviation and travel sectors, including airline reservation centers, airport operations and travel agency systems. Over 450,000 computer terminals were manufactured between 1972 and 2002 and refurbishments are still supported today, with many units still in use globally at airlines and airports. The company diversified into airline software development in 1987.
In 1976, Videcom International along with British Airways, British Caledonian and CCL, launched Travicom, the world's first multi-access reservations system. It was wholly based on Videcom technology. They formed a network to thousands of travel agents in the UK providing distribution for 49 subscribing international airlines, including British Airways, British Caledonian, TWA, Pan American World Airways, Qantas, Singapore Airlines, Air France, Lufthansa, SAS, Air Canada, KLM, Alitalia, Cathay Pacific, JAL) and some African airlines. It allowed agents and airlines to communicate via a common distribution language and network, handling 97% of UK airline business trade bookings by 1987.
The system went on to be replicated by Videcom in other areas of the world including the Middle East (DMARS), New Zealand, Kuwait (KMARS), Ireland, Caribbean, United States and Hong Kong. The Travicom multi access system was eventually replaced by Galileo in the UK and in 1988, Trave |
https://en.wikipedia.org/wiki/Friday%20Harbor%20Laboratories | Friday Harbor Laboratories (FHL), is a marine biology field station of the University of Washington, located in Friday Harbor, San Juan Island, Washington, United States. Friday Harbor Labs is known for its intensive summer classes offered to competitive graduate students from around the world in fields of marine biology and other marine sciences.
Autumn and spring academic terms include courses designed for advanced undergraduates as well as graduate students; most spring and fall classes run 10 weeks and feature an original research component. In addition to serving students, Friday Harbor Laboratories has a small resident scientific staff and offers year-round laboratory, library, and housing accommodations for visiting researchers and their families. Research areas include marine algae, marine conservation biology, marine invertebrate zoology, comparative invertebrate embryology, experimental and field approaches in biology and paleontology, functional morphology and ecology of marine fishes, invertebrate larval ecology, and other current topics in marine science and oceanography.
FHL was founded in 1904 by University of Washington Zoology Professor Trevor Kincaid, who became its first director. The Green fluorescent protein was discovered at FHL in 1962. There is a sculpture by Julian Voss-Andreae at the campus to commemorate the discovery.
In 2004, zoologist Patricia Louise Dudley, who had spent many summers at the Laboratory, created an endowment to support "research or scholarships for the study of systematics, the structure of marine organisms, or for marine invertebrate ecology". She directed that fund recipients spend significant time at Friday Harbor, and added her desire that "findings contribute to the understanding of evolutionary relationships". |
https://en.wikipedia.org/wiki/Matbucha | Matbucha (; , maṭbūkhah) is a Moroccan cuisine condiment or cooked salad consisting of cooked tomatoes and roasted bell peppers seasoned with garlic and chili pepper, and slow-cooked for a number of hours. It is traditionally served on Shabbat with challah or "home bread" (a traditional Moroccan bread just for serving with matbucha), and is a condiment typically served as part of an appetizer, often as part of a salatim, or salad course.
It may be used as a base for shakshuka.
Preparation
Matbucha is prepared by cooking tomatoes, bell peppers, chilis, and garlic over low heat for many hours until they cook down into a smooth, thick spread similar to jam in consistency.
Commercial variants
Commercially-produced matbucha has been commonly sold throughout Israel at most grocery stores for decades, and is available in both the refrigerated and shelf stable varieties. Brands include Sabra, Osem, and others. In recent years matbucha has become available in the United States under the NY Shuk brand, among several others.
See also
Arab cuisine
Shakshuka, a similar dish with eggs
List of Moroccan dishes |
https://en.wikipedia.org/wiki/Luminous%20red%20nova | A luminous red nova (abbr. LRN, pl. luminous red novae, pl.abbr. LRNe) is a stellar explosion thought to be caused by the merging of two stars. They are characterised by a distinct red colour, and a light curve that fades slowly with resurgent brightness in the infrared. Luminous red novae are not related to standard novae, which are explosions that occur on the surface of white dwarf stars.
Discovery
A small number of objects exhibiting the characteristics of luminous red novae have been observed over the last 30 years or so. The red star M31 RV in the Andromeda Galaxy flared brightly during 1988 and may have been a luminous red nova. In 1994, V4332 Sagittarii, a star in the Milky Way galaxy, flared similarly, and in 2002, V838 Monocerotis followed suit and was studied quite closely.
The first confirmed luminous red nova was the object M85 OT2006-1, in the galaxy Messier 85. It was first observed during the Lick Observatory Supernova Search, and subsequently investigated by a team of astronomers from both U.C. Berkeley and Caltech. They confirmed its difference from known explosions such as novae and thermal pulses, and announced luminous red novae as a new class of stellar explosion.
V1309 Scorpii is a luminous red nova that followed the merger of a contact binary in 2008. In January 2015, a luminous red nova was observed in the Andromeda Galaxy. On February 10, 2015, a luminous red nova, known as M101 OT2015-1 was discovered in the Pinwheel Galaxy.
Characteristics
The luminosity of the explosion occurring in luminous red novae is between that of a supernova (which is brighter) and a nova (dimmer). The visible light lasts for weeks or months, and is distinctively red in colour, becoming dimmer and redder over time. As the visible light dims, the infrared light grows and also lasts for an extended period of time, usually dimming and brightening a number of times.
Infrared observations of M85 OT2006-1 have shown that temperature of this star is slightly less |
https://en.wikipedia.org/wiki/Unwired%20enterprise | An unwired enterprise is an organization that extends and supports the use of traditional thick client enterprise applications to a variety of mobile devices and their users throughout the organization. The abiding characteristic is seamless universal mobile access to critical applications and business data.
Use
By supporting mobile clients alongside more traditional desktop and laptop clients, an unwired enterprise attempts to increase productivity rates and speed the pace of many common business processes through anytime/anywhere accessibility. Furthermore, it is believed that supporting mobile access to enterprise applications can help facilitate cogent decision making by pulling business data in real time from server systems and making it available to the mobile workforce at the decision point.
Even though the wireless network is quite ubiquitous, this type of client application requires built-in procedures to deal with any network unavailability seamlessly, without interfering with application core functionality. Pervasive broadband, simplified wireless integration and a common management system are technology trends driving more organizations toward an unwired enterprise due to lowering complexity and greater ease of use.
Unwired enterprises may include office environments in which workers are untethered from traditional desktop clients and conduct all business and communication from a wide variety of wireless devices. In the unwired enterprise, client platform and operating system are deemphasized as focus shifts away from platform homogeneity to fluid and expedient data exchange and technology agnosticism. Open standards industry initiatives such as the Open Handset Alliance are designed to help mobile technology vendors deliver on this promise. |
https://en.wikipedia.org/wiki/Les%20Houches%20Accords | The Les Houches Accords are agreements between particle physicists to standardize the interface between the matrix element programs and the event generators used to calculate different quantities. The original accord was initially formed in 2001, at a conference in Les Houches, in the French Alps, before it was subsequently expanded.
In experimental high energy physics, several levels of computing are used to simulate data runs, including programs that generate matrix elements and ones that generate events. However, there are several programs for each of these tasks, such as CompHEP and MadGraph to generate matrix elements, and PYTHIA and HERWIG for event generation. Depending on specific properties of the particle decay that physicists are interested in, they may desire to use a certain program for these tasks, but before the Les Houches Accords, there was no general interface for communicating between the programs. This enables physicists to choose more freely between different programs. The Accords also make it easier to generate parton distribution functions, which are datasets used to calculate cross sections, for events.
The original Accord defined a programmatic interface for transfer of event information, in terms of Fortran common blocks, but no data exchange file format was defined until 2006.
Events that conform to the formats described in the Les Houches Accords are said to be in Les Houches Event format, or more often, LHE format.
See also
Event generator
Sources
The original paper:
Les Houches Event Format paper:
General overview:
General information:
Example:
Computational particle physics
Computational physics |
https://en.wikipedia.org/wiki/Michael%20H.%20Albert | Michael Henry Albert (born September 20, 1962) is a mathematician and computer scientist, originally from Canada, and currently a professor in the computer science department at the University of Otago in Dunedin, New Zealand. His varied research interests include combinatorics and combinatorial game theory.
Education and career
Albert received his B.Math in 1981 from the University of Waterloo. In that year Albert received the Rhodes Scholarship, and he completed his D. Phil. in 1984 at the University of Oxford. He then returned to the University of Waterloo. From 1987 to 1996 he was a professor at Carnegie Mellon University. Albert has been at the University of Otago since 1998.
Contributions
Together with J.P. Grossman and Richard Nowakowski, Albert invented the game Clobber. Albert has also contributed to the Combinatorial Game Suite game analysis software, and is a coauthor of Lessons in Play: An Introduction to Combinatorial Game Theory. Another significant topic of his research has been permutation patterns.
See also
List of University of Waterloo people |
https://en.wikipedia.org/wiki/Molecular%20binding | Molecular binding is an attractive interaction between two molecules that results in a stable association in which the molecules are in close proximity to each other. It is formed when atoms or molecules bind together by sharing of electrons. It often, but not always, involves some chemical bonding.
In some cases, the associations can be quite strong—for example, the protein streptavidin and the vitamin biotin have a dissociation constant (reflecting the ratio between bound and free biotin) on the order of 10−14—and so the reactions are effectively irreversible. The result of molecular binding is sometimes the formation of a molecular complex in which the attractive forces holding the components together are generally non-covalent, and thus are normally energetically weaker than covalent bonds.
Molecular binding occurs in biological complexes (e.g., between pairs or sets of proteins, or between a protein and a small molecule ligand it binds) and also in abiologic chemical systems, e.g. as in cases of coordination polymers and coordination networks such as metal-organic frameworks.
Types
Molecular binding can be classified into the following types:
Non-covalent – no chemical bonds are formed between the two interacting molecules hence the association is fully reversible
Reversible covalent – a chemical bond is formed, however the free energy difference separating the noncovalently-bonded reactants from bonded product is near equilibrium and the activation barrier is relatively low such that the reverse reaction which cleaves the chemical bond easily occurs
Irreversible covalent – a chemical bond is formed in which the product is thermodynamically much more stable than the reactants such that the reverse reaction does not take place.
Bound molecules are sometimes called a "molecular complex"—the term generally refers to non-covalent associations. Non-covalent interactions can effectively become irreversible; for example, tight binding inhibitors of enzymes |
https://en.wikipedia.org/wiki/Neurotechnology%20Industry%20Organization | The Neurotechnology Industry Organization (NIO) is a San Francisco, California based non-profit trade association that represents a broad spectrum of companies involved in neuroscience, brain research centers, and advocacy groups from around the globe. Operating as a coalition of organizations in the field of neurotechnology, the goal of NIO is to enhance awareness of brain and nervous system illnesses, as well as to promote and advocate for treatment and diagnostic options.
See also
Brain-computer interface
Brain implant
Neuroprosthetics
Neural Engineering
Transcranial magnetic stimulation
Enablement (disambiguation)
External links
NeurotechIndustry.org - Official website
Neurotechnology
Neural engineering |
https://en.wikipedia.org/wiki/Markov%20partition | A Markov partition in mathematics is a tool used in dynamical systems theory, allowing the methods of symbolic dynamics to be applied to the study of hyperbolic dynamics. By using a Markov partition, the system can be made to resemble a discrete-time Markov process, with the long-term dynamical characteristics of the system represented as a Markov shift. The appellation 'Markov' is appropriate because the resulting dynamics of the system obeys the Markov property. The Markov partition thus allows standard techniques from symbolic dynamics to be applied, including the computation of expectation values, correlations, topological entropy, topological zeta functions, Fredholm determinants and the like.
Motivation
Let be a discrete dynamical system. A basic method of studying its dynamics is to find a symbolic representation: a faithful encoding of the points of by sequences of symbols such that the map becomes the shift map.
Suppose that has been divided into a number of pieces which are thought to be as small and localized, with virtually no overlaps. The behavior of a point under the iterates of can be tracked by recording, for each , the part which contains . This results in an infinite sequence on the alphabet which encodes the point. In general, this encoding may be imprecise (the same sequence may represent many different points) and the set of sequences which arise in this way may be difficult to describe. Under certain conditions, which are made explicit in the rigorous definition of a Markov partition, the assignment of the sequence to a point of becomes an almost one-to-one map whose image is a symbolic dynamical system of a special kind called a shift of finite type. In this case, the symbolic representation is a powerful tool for investigating the properties of the dynamical system .
Formal definition
A Markov partition is a finite cover of the invariant set of the manifold by a set of curvilinear rectangles such that
For any pair of poi |
https://en.wikipedia.org/wiki/Karger%27s%20algorithm | In computer science and graph theory, Karger's algorithm is a randomized algorithm to compute a minimum cut of a connected graph. It was invented by David Karger and first published in 1993.
The idea of the algorithm is based on the concept of contraction of an edge in an undirected graph . Informally speaking, the contraction of an edge merges the nodes and into one, reducing the total number of nodes of the graph by one. All other edges connecting either or are "reattached" to the merged node, effectively producing a multigraph. Karger's basic algorithm iteratively contracts randomly chosen edges until only two nodes remain; those nodes represent a cut in the original graph. By iterating this basic algorithm a sufficient number of times, a minimum cut can be found with high probability.
The global minimum cut problem
A cut in an undirected graph is a partition of the vertices into two non-empty, disjoint sets . The cutset of a cut consists of the edges between the two parts. The size (or weight) of a cut in an unweighted graph is the cardinality of the cutset, i.e., the number of edges between the two parts,
There are ways of choosing for each vertex whether it belongs to or to , but two of these choices make or empty and do not give rise to cuts. Among the remaining choices, swapping the roles of and does not change the cut, so each cut is counted twice; therefore, there are distinct cuts.
The minimum cut problem is to find a cut of smallest size among these cuts.
For weighted graphs with positive edge weights the weight of the cut is the sum of the weights of edges between vertices in each part
which agrees with the unweighted definition for .
A cut is sometimes called a “global cut” to distinguish it from an “- cut” for a given pair of vertices, which has the additional requirement that and . Every global cut is an - cut for some . Thus, the minimum cut problem can be solved in polynomial time by iterating over all choices of and |
https://en.wikipedia.org/wiki/Steelbox%20Networks | Steelbox Networks Inc. was a privately owned company that engineered devices to distribute, store and retrieve large amounts of video data across IP networks. The company was noted for revolutionizing the video surveillance industry through the development of a specialized digital operating system (RTIK) addressing specific needs of video security networks such as problems with large scale storage and playback control. The technology provides secure paths to distribute, store and playback large amounts of live and recorded video. Its primary customer base was businesses and organizations that use video monitoring systems, such as law enforcement, military and transportation.
Corporate history
Steelbox was founded in 2003 in Atlanta, Georgia by six engineers most of whom have worked together for 20 years and completed projects for Cisco Systems, Scientific Atlanta and Nortel Networks. The core team developed the operating system behind the Cisco PIX Firewall, which is widely used throughout the world today. The team also developed the concept of load balancing, a technology that speeds up the flow of information over the Internet by determining the best way to route data requests to the most appropriate sources. Prior to Steelbox, the founders worked for Pharsalia Technologies, which was led by Steelbox CEO, Richard "Chip" Howes. Howes holds 30 patents for designs related to securing and speeding the flow of information over the Internet.
Founders
Richard "Chip" Howes
Bill LeBlanc
Jim Jordan
Tom Bohannon
Scott Higgins
Bill Vaughan
Sample of Customers
UK Highways Agency
Moscow Metro
National Roads Telecommunication Services
Port of Oostende, Belgium Products/ Solutions
A Critic
"The New York City Transit Authority purchased 36 of these units along with a DMSS for each, and had nothing but problems. After a multitude of firmware updates, visits by their field engineers, and failures in the field, they wished they had gone with another vendor such as NICE or Tele |
https://en.wikipedia.org/wiki/Polar%20homology | In complex geometry, a polar homology is a group which captures holomorphic invariants of a complex manifold in a similar way to usual homology of a manifold in differential topology. Polar homology was defined by B. Khesin and A. Rosly in 1999.
Definition
Let M be a complex projective manifold. The space of polar k-chains is a vector space over defined as a quotient , with and vector spaces defined below.
Defining Ak
The space is freely generated by the triples , where X is a smooth, k-dimensional complex manifold, a holomorphic map, and is a rational k-form on X, with first order poles on a divisor with normal crossing.
Defining Rk
The space is generated by the following relations.
if .
provided that
where
for all and the push-forwards are considered on the smooth part of .
Defining the boundary operator
The boundary operator is defined by
,
where are components of the polar divisor of , res is the Poincaré residue, and are restrictions of the map f to each component of the divisor.
Khesin and Rosly proved that this boundary operator is well defined, and satisfies . They defined the polar cohomology as the quotient .
Notes
B. Khesin, A. Rosly, Polar Homology and Holomorphic Bundles Phil. Trans. Roy. Soc. Lond. A359 (2001) 1413-1428
Complex manifolds
Several complex variables
Homology theory |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.