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https://en.wikipedia.org/wiki/Markov%20blanket | In statistics and machine learning, when one wants to infer a random variable with a set of variables, usually a subset is enough, and other variables are useless. Such a subset that contains all the useful information is called a Markov blanket. If a Markov blanket is minimal, meaning that it cannot drop any variable without losing information, it is called a Markov boundary. Identifying a Markov blanket or a Markov boundary helps to extract useful features. The terms of Markov blanket and Markov boundary were coined by Judea Pearl in 1988. A Markov blanket can be constituted by a set of Markov chains.
Markov blanket
A Markov blanket of a random variable in a random variable set is any subset of , conditioned on which other variables are independent with :
It means that contains at least all the information one needs to infer , where the variables in are redundant.
In general, a given Markov blanket is not unique. Any set in that contains a Markov blanket is also a Markov blanket itself. Specifically, is a Markov blanket of in .
Markov boundary
A Markov boundary of in is a subset of , that itself is a Markov blanket of , but any proper subset of is not a Markov blanket of . In other words, a Markov boundary is a minimal Markov blanket.
The Markov boundary of a node in a Bayesian network is the set of nodes composed of 's parents, 's children, and 's children's other parents. In a Markov random field, the Markov boundary for a node is the set of its neig |
https://en.wikipedia.org/wiki/Causal%20Markov%20condition | The Markov condition, sometimes called the Markov assumption, is an assumption made in Bayesian probability theory, that every node in a Bayesian network is conditionally independent of its nondescendants, given its parents. Stated loosely, it is assumed that a node has no bearing on nodes which do not descend from it. In a DAG, this local Markov condition is equivalent to the global Markov condition, which states that d-separations in the graph also correspond to conditional independence relations. This also means that a node is conditionally independent of the entire network, given its Markov blanket.
The related Causal Markov (CM) condition states that, conditional on the set of all its direct causes, a node is independent of all variables which are not effects or direct causes of that node. In the event that the structure of a Bayesian network accurately depicts causality, the two conditions are equivalent. However, a network may accurately embody the Markov condition without depicting causality, in which case it should not be assumed to embody the causal Markov condition.
Motivation
Statisticians are enormously interested in the ways in which certain events and variables are connected. The precise notion of what constitutes a cause and effect is necessary to understand the connections between them. The central idea behind the philosophical study of causation is that causes raise the probabilities of their effects, all else being equal.
A deterministic interpretatio |
https://en.wikipedia.org/wiki/Dolores%20%22LaLa%22%20Brooks | Dolores Brooks (born June 20, 1947), also known as Sakinah Muhammad, is the second lead singer of the girl group the Crystals. She is best known as the lead vocalist on the Crystals' hits "Then He Kissed Me" and "Da Doo Ron Ron".
About
Brooks was the second youngest of 11 children, born to a Native American mother and an African-American father.
Brooks first displayed her talent by singing gospel music in church. At age seven, she took part in her siblings' gospel group, "Little Gospel Tears", and sang in Brooklyn. While attending PS 73, she was discovered in an after-school program by Dolores "Dee Dee" Kenniebrew and her mother, who invited Brooks to join the Crystals as a replacement for a departing member. She joined the group to replace Merna Girard (who was pregnant) on the March 1962 release "Uptown".
After leaving the Crystals, she married jazz and session musician Idris Muhammad (born Leo Morris) in 1966; the union brought two sons and two daughters. Shortly thereafter, she converted to Islam with him, changing her name to Sakinah Muhammad. She helped Idris write and record his material over the years. In 1968, she appeared in the original Broadway production of the musical Hair, where she sometimes performed the song "Aquarius". She later appeared in the Broadway show Two Gentlemen of Verona in 1971. She also toured with, and recorded for, various artists, such as the Neville Brothers, Bobby Womack and Isaac Hayes. She made short appearances in films, and contribu |
https://en.wikipedia.org/wiki/Phase%20distortion%20synthesis | Phase distortion (PD) synthesis is a synthesis method introduced in 1984 by Casio in its CZ range of synthesizers. In outline, it is similar to phase modulation synthesis as championed by Yamaha Corporation (under the name of frequency modulation), in the sense that both methods dynamically change the harmonic content of a carrier waveform by influence of another waveform (modulator) in the time domain. However, the application and results of the two methods are quite distinct.
Casio made five different synthesizers using their original concept of PD synthesis (with variations). The later VZ-1 and co's synthesis method Interactive phase distortion is much more similar to the aforementioned phase modulation, rather than a direct evolution of phase distortion; see below.
Generating harmonic content
Casio's implementation of PD used oscillators generated by modulator and carrier waveforms, synchronised to each other per-cycle. The modulators were various angular waves that could 'distort' the carrier's sine into other shapes, to a degree derived from the "DCW" envelope. In doing so, many harmonics were created in the output. As modulators were rich in harmonic content, they could create spectra more linear, i.e. more similar to traditional subtractive spectra, than Yamaha's phase modulation (PM/FM) synthesis. PM does not require oscillator sync but was for a long time limited to sine waves, which meant output spectra bore the non-linear hallmark of Bessel functions. PD is a di |
https://en.wikipedia.org/wiki/Thioredoxin | Thioredoxin (TRX or TXN) is a class of small redox proteins known to be present in all organisms. It plays a role in many important biological processes, including redox signaling. In humans, thioredoxins are encoded by TXN and TXN2 genes. Loss-of-function mutation of either of the two human thioredoxin genes is lethal at the four-cell stage of the developing embryo. Although not entirely understood, thioredoxin is linked to medicine through their response to reactive oxygen species (ROS). In plants, thioredoxins regulate a spectrum of critical functions, ranging from photosynthesis to growth, flowering and the development and germination of seeds. Thioredoxins play a role in cell-to-cell communication.
Occurrence
They are found in nearly all known organisms and are essential for life in mammals.
Function
The primary function of thioredoxin (Trx) is the reduction of oxidized cysteine residues and the cleavage of disulfide bonds. Multiple in vitro substrates for thioredoxin have been identified, including ribonuclease, choriogonadotropins, coagulation factors, glucocorticoid receptor, and insulin. Reduction of insulin is classically used as an activity test. The thioredoxins are maintained in their reduced state by the flavoenzyme thioredoxin reductase, in a NADPH-dependent reaction. Thioredoxins act as electron donors to peroxidases and ribonucleotide reductase. The related glutaredoxins share many of the functions of thioredoxins, but are reduced by glutathione rather th |
https://en.wikipedia.org/wiki/Pasch%27s%20theorem | In geometry, Pasch's theorem, stated in 1882 by the German mathematician Moritz Pasch, is a result in plane geometry which cannot be derived from Euclid's postulates.
Statement
The statement is as follows: [Here, for example, (, , ) means that point lies between points and .]
See also
Ordered geometry
Pasch's axiom
Notes
References
External links
Euclidean plane geometry
Foundations of geometry
Order theory
Theorems in plane geometry |
https://en.wikipedia.org/wiki/Biaxial%20nematic | A biaxial nematic is a spatially homogeneous liquid crystal with three distinct optical axes. This is to be contrasted to a simple nematic, which has a single preferred axis, around which the system is rotationally symmetric. The symmetry group of a biaxial nematic is i.e. that of a rectangular right parallelepiped, having 3 orthogonal axes and three orthogonal mirror planes. In a frame co-aligned with optical axes the second rank order parameter tensor of a biaxial nematic has the form
where is the standard nematic scalar order parameter and is a measure of the biaxiality.
The first report of a thermotropic biaxial nematic appeared in 2004 based on a boomerang shaped oxadiazole bent-core mesogen. The biaxial nematic phase for this particular compound only occurs at temperatures around 200 °C and is preceded by as yet unidentified smectic phases.
It is also found that this material can segregate into chiral domains of opposite handedness. For this to happen the boomerang shaped molecules adopt a helical superstructure.
In one azo bent-core mesogen a thermal transition is found from a uniaxial Nu to a biaxial nematic Nb mesophase, as predicted by theory and simulation. This transition is observed on heating from the Nu phase with Polarizing optical microscopy as a change in Schlieren texture and increased light transmittance and from x-ray diffraction as the splitting of the nematic reflection. The transition is a second order transition with low energy content an |
https://en.wikipedia.org/wiki/P6 | P6, P-6, or P.6 may refer to:
P6 (microarchitecture), a sixth-generation Intel x86 microprocessor microarchitecture
POWER6, a sixth-generational IBM microprocessor microarchitecture
p6 protein, a protein of HIV
HAT-P-6, a star in the constellation Andromeda
Integrated Truss Structure#P6, S6 trusses, trusses on the International Space Station
Rover P6 series, a saloon car model produced from 1963 to 1977 in Solihull, West Midlands, England
SIG Sauer P225/P6, a variant of the P225 pistol used by West German police forces
Pentacon Six, a single-lens reflex (SLR) medium format camera system
Period 6, a period of the periodic table of elements
Primavera P6, a project management software package by Primavera (software)
IATA code for Privilege Style, a charter airline
Principle 6 campaign, opposing anti-gay Russian laws at the 2014 Olympics
P6 ATAV, an Indonesian light attack vehicle
P-6, a variant of the Cold War era Soviet naval cruise missile SS-N-3A Shaddock
PPPPPP (manga), a short hand for the manga by Maporo 3-Gō.
Netpbm File_formats, binary ppm file
Aircraft
Curtiss P-6 Hawk, a 1927 American single-engine biplane fighter
Piaggio P.6, a 1927 Italian catapult-launched reconnaissance floatplane
PZL P.6, a 1930 Polish fighter
See also
P600 (neuroscience), an event-related potential
6P (disambiguation)
PPPPPP (disambiguation) |
https://en.wikipedia.org/wiki/P1 | P1, P01, P-1 or P.1 may refer to:
Computing, robotics, and, telecommunications
DSC-P1, a 2000 Sony Cyber-shot P series camera model
Sony Ericsson P1, a UIQ 3 smartphone
Packet One, the first company to launch WiMAX service in Southeast Asia
Peer 1, an Internet hosting provider
Honda P1, a 1993 Honda P series of robots, an ASIMO predecessor
Media
DR P1, a Danish radio network operated by Danmarks Radio
NRK P1, a Norwegian radio network operated by the Norwegian Broadcasting Corporation
SR P1, a Swedish radio network operated by Sveriges Radio
Polonia 1, a Polish TV channel of the Polcast Television
Military
P-1 Hawk, a 1923 biplane fighter of the U.S. Army Air Corps
Kawasaki P-1, a Japanese maritime patrol aircraft (previously P-X)
P-1 (missile), a Soviet anti-ship cruise missile
Science
Biology
P1 antigen, identifies P antigen system
P1 laboratory, biosafety -level-1 laboratory
P1 phage, a bacterial virus
SARS-CoV-2 Gamma variant, a strain of COVID-19 virus SARS-CoV-2 first detected in Manaus, Brazil in 2020
ATC code P01 Antiprotozoals, a subgroup of the Anatomical Therapeutic Chemical Classification System
Pericarp color1 (p1), a gene in the phlobaphene biosynthesis pathway in maize
C1 and P1 (neuroscience), a component of the visual evoked potential
P1 nuclease, a nuclease that works on single-stranded DNA as well as RNA
Other sciences
Period 1 of the periodic table
Pollard's p − 1 algorithm for integer factorization
P-ONE - a proposed neutri |
https://en.wikipedia.org/wiki/Jessica%20Utts | Jessica Utts (born 1952) is a parapsychologist and statistics professor at the University of California, Irvine. She is known for her textbooks on statistics and her investigation into remote viewing.
Statistics education
In 2003, Utts published an article in American Statistician, a journal published by the American Statistical Association, calling for significant changes to collegiate level statistics education. In the article she argued that curricula do a fine job of covering the mathematical side of statistics, but do a poor job of teaching students the skills necessary to properly interpret statistical results in scientific studies. The argument continues that common errors found in news articles, such as the common misinterpretation that correlative studies show causation, would be reduced if there were significant changes made to standard statistics courses.
In 2016, Utts served as the 111th president of the American Statistical Association.
She is a Fellow of the American Statistical Association, and also a Fellow of the Institute of Mathematical Statistics.
Investigation of remote viewing
In 1995, the American Institutes for Research (AIR) appointed a panel consisting primarily of Utts and Ray Hyman to evaluate a project investigating remote viewing for espionage applications, the Stargate Project, which was funded by the Central Intelligence Agency and Defense Intelligence Agency, and carried out initially by Stanford Research Institute and subsequently by S |
https://en.wikipedia.org/wiki/Society%20of%20Economic%20Geologists | The Society of Economic Geologists (SEG) is a scientific organization that promotes the study of geology as it relates to mining, mineral exploration, mineral resource classification and mineral extraction. The society's Publication Board publishes the scientific journal Economic Geology. The society serves 7,000+ members worldwide who are committed to advancing the science and the discovery of mineral resources through research, publications, courses, and field trips.
History
SEG began in 1919 with a group of Geological Society of America (GSA) with an interest in economic geology. December 28, 1920, 60 distinguished professionals met and established the organization.
Notable economic geologists
Pavel Pavlovich Goudkoff (Gudkov) (1921). He was the organizer of the journal "Economic Geology" also.
Josiah E. Spurr (1923-1924)
William E. Wrather (1934-1935)
William O. Hotchkiss, President (1946-1947)
Anthony J. Naldrett, President (1991-1992)
See also
List of geoscience organizations
References
External links
SEG publications (Economic Geology and the SEG Newsletter)
Geofacets - Geofacets-SEG Millennium Edition
Official website
Economic Geology at the GSW website
Geology societies
Economic geology
Mining organizations
1920 establishments in the United States
Scientific organizations established in 1920 |
https://en.wikipedia.org/wiki/Drug%20metabolism | Drug metabolism is the metabolic breakdown of drugs by living organisms, usually through specialized enzymatic systems. More generally, xenobiotic metabolism (from the Greek xenos "stranger" and biotic "related to living beings") is the set of metabolic pathways that modify the chemical structure of xenobiotics, which are compounds foreign to an organism's normal biochemistry, such as any drug or poison. These pathways are a form of biotransformation present in all major groups of organisms and are considered to be of ancient origin. These reactions often act to detoxify poisonous compounds (although in some cases the intermediates in xenobiotic metabolism can themselves cause toxic effects). The study of drug metabolism is called pharmacokinetics.
The metabolism of pharmaceutical drugs is an important aspect of pharmacology and medicine. For example, the rate of metabolism determines the duration and intensity of a drug's pharmacologic action. Drug metabolism also affects multidrug resistance in infectious diseases and in chemotherapy for cancer, and the actions of some drugs as substrates or inhibitors of enzymes involved in xenobiotic metabolism are a common reason for hazardous drug interactions. These pathways are also important in environmental science, with the xenobiotic metabolism of microorganisms determining whether a pollutant will be broken down during bioremediation, or persist in the environment. The enzymes of xenobiotic metabolism, particularly the glutathi |
https://en.wikipedia.org/wiki/First%20pass%20effect | The first pass effect (also known as first-pass metabolism or presystemic metabolism) is a phenomenon of drug metabolism at a specific location in the body which leads to a reduction in the concentration of the active drug, specifically when administered orally, before it reaches the site of action or systemic circulation. It is the fraction of drug lost during the process of absorption which is generally related to the liver and gut wall. The liver is the major site of first pass effect; it can also occur in the lungs, vasculature or other metabolically active tissues in the body. Notable drugs that experience a significant first-pass effect are buprenorphine, chlorpromazine, cimetidine, diazepam, ethanol (drinking alcohol), imipramine, insulin, lidocaine, midazolam, morphine, pethidine, propranolol, and tetrahydrocannabinol (THC).
First pass metabolism may occur in the liver (for propranolol, lidocaine, clomethiazole, and nitroglycerin) or in the gut (for benzylpenicillin and insulin).
After a drug is swallowed, it is absorbed by the digestive system and enters the hepatic portal system. It is carried through the portal vein into the liver before it reaches the rest of the body. The liver metabolizes many drugs, sometimes to such an extent that only a small amount of active drug emerges from the liver to the rest of the circulatory system. This first pass through the liver thus may greatly reduce the bioavailability of the drug.
An example of a drug where first pass meta |
https://en.wikipedia.org/wiki/Epoxide%20hydrolase | Epoxide hydrolases (EHs), also known as epoxide hydratases, are enzymes that metabolize compounds that contain an epoxide residue; they convert this residue to two hydroxyl residues through an epoxide hydrolysis reaction to form diol products. Several enzymes possess EH activity. Microsomal epoxide hydrolase (epoxide hydrolase 1, EH1, or mEH), soluble epoxide hydrolase (sEH, epoxide hydrolase 2, EH2, or cytoplasmic epoxide hydrolase), and the more recently discovered but not as yet well defined functionally, epoxide hydrolase 3 (EH3) and epoxide hydrolase 4 (EH4) are structurally closely related isozymes. Other enzymes with epoxide hydrolase activity include leukotriene A4 hydrolase, Cholesterol-5,6-oxide hydrolase, MEST (gene) (Peg1/MEST), and Hepoxilin-epoxide hydrolase. The hydrolases are distinguished from each other by their substrate preferences and, directly related to this, their functions.
Classification
mEH (EH1), sEH (EH2), EH3, and EH4 isozymes
Humans express four epoxide hydrolase isozymes: mEH, sEH, EH3, and EH4. These isozymes are known (mEH and sEH) or presumed (EH3 and EH4) to share a common structure that includes containing an Alpha/beta hydrolase fold and a common reaction mechanism wherein they add water to epoxides to form vicinal cis (see (cis-trans isomerism); see (epoxide#Olefin (alkene) oxidation using organic peroxides and metal catalysts)) diol products. They differ, however, in subcellular location, substrate preferences, tissue expression, an |
https://en.wikipedia.org/wiki/Adult%20T-cell%20leukemia/lymphoma | Adult T-cell leukemia/lymphoma (ATL or ATLL) is a rare cancer of the immune system's T-cells caused by human T cell leukemia/lymphotropic virus type 1 (HTLV-1). All ATL cells contain integrated HTLV-1 provirus further supporting that causal role of the virus in the cause of the neoplasm. A small amount of HTLV-1 individuals progress to develop ATL with a long latency period between infection and ATL development. ATL is categorized into 4 subtypes: acute, smoldering, lymphoma-type, chronic. Acute and Lymphoma-type are known to particularity be aggressive with poorer prognosis.
Globally, the retrovirus HTLV-1 is estimated to infect 20 million people with the incidence of ATL approximately 0.05 per 100,000 with endemic regions such as regions of Japan, as high as 27 per 100,000. However, cases have increased in non-endemic regions with highest incidence of HTLV-1 in southern/northern islands of Japan, Caribbean, Central and South America, intertropical Africa, Romania, northern Iran. ATL normally occurs around the age of 62 years but median age at diagnosis does depend on prevalence of the HTLV-1 infection in the geographic location.
Current treatment regiments for ATL are based on clinical subtype and response to initial therapy. Some therapy modalities for treatment may not available in all countries therefore strategies differ across the world. All patients are referred to clinical trials if available. Beyond clinical trials, treatments are centered on multiagent chemother |
https://en.wikipedia.org/wiki/P0 | P0 or p0 may refer to:⁰
P0 protein
lppp Standard atmospheric pressure of 101325 Pa
Neutronium, hypothetically occupying Period 0 in the periodic table
Proflight Zambia IATA airline coo
See also
0P (disambiguation)
PO (disambiguation) |
https://en.wikipedia.org/wiki/Open%20reading%20frame | In molecular biology, open reading frames (ORFs) are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames will be "open" (the "reading", however, refers to the RNA produced by transcription of the DNA and its subsequent interaction with the ribosome in translation). Such an ORF may contain a start codon (usually AUG in terms of RNA) and by definition cannot extend beyond a stop codon (usually UAA, UAG or UGA in RNA). That start codon (not necessarily the first) indicates where translation may start. The transcription termination site is located after the ORF, beyond the translation stop codon. If transcription were to cease before the stop codon, an incomplete protein would be made during translation.
In eukaryotic genes with multiple exons, introns are removed and exons are then joined together after transcription to yield the final mRNA for protein translation. In the context of gene finding, the start-stop definition of an ORF therefore only applies to spliced mRNAs, not genomic DNA, since introns may contain stop codons and/or cause shifts between reading frames. An alternative definition says that an ORF is a sequence that has a length divisible by three and is bounded by stop codons. This more general definition can be useful in the context of transcriptomics and metagenomics, where a start or stop codon may not be present |
https://en.wikipedia.org/wiki/Primary%20battery | A primary battery or primary cell is a battery (a galvanic cell) that is designed to be used once and discarded, and not recharged with electricity and reused like a secondary cell (rechargeable battery). In general, the electrochemical reaction occurring in the cell is not reversible, rendering the cell unrechargeable. As a primary cell is used, chemical reactions in the battery use up the chemicals that generate the power; when they are gone, the battery stops producing electricity. In contrast, in a secondary cell, the reaction can be reversed by running a current into the cell with a battery charger to recharge it, regenerating the chemical reactants. Primary cells are made in a range of standard sizes to power small household appliances such as flashlights and portable radios.
Primary batteries make up about 90% of the $50 billion battery market, but secondary batteries have been gaining market share. About 15 billion primary batteries are thrown away worldwide every year, virtually all ending up in landfills. Due to the toxic heavy metals and strong acids and alkalis they contain, batteries are hazardous waste. Most municipalities classify them as such and require separate disposal. The energy needed to manufacture a battery is about 50 times greater than the energy it contains. Due to their high pollutant content compared to their small energy content, the primary battery is considered a wasteful, environmentally unfriendly technology. Due mainly to increasing sales o |
https://en.wikipedia.org/wiki/George%20Barna | George Barna (born 1954) is the founder of The Barna Group, a market research firm specializing in studying the religious beliefs and behavior of Americans, and the intersection of faith and culture. From 2013 - 2018 he served as the executive director of the American Culture & Faith Institute, the research division of United in Purpose. In 2019 he became a professor at Arizona Christian University in Phoenix, Arizona, where he also started the Cultural Research Center at Arizona Christian University. He is also the senior research fellow for Christian ethics and Biblical worldview at Family Research Council.
Background
George Barna grew up a Catholic in New York City and Princeton, New Jersey but he has since engaged with evangelical Christianity.
Barna has filled executive roles in politics, marketing, advertising, media development, research and ministry. He founded the Barna Research Group in 1984 (now The Barna Group), a marketing research firm focused on the intersection of faith and culture. Through the Barna Group, George served several hundred parachurch ministries, thousands of Christian churches, and many other non-profit and for-profit organizations as well as the U.S. military. He sold it in 2009.
He currently serves as the president of Metaformation, a faith development organization.
Barna has written more than 50 books, mostly addressing cultural trends, leadership, spiritual development, and church dynamics. They include New York Times bestsellers and sev |
https://en.wikipedia.org/wiki/British%20Rail%20Class%2098 | The British Rail Class 98 is a Total Operations Processing System (TOPS) classification that has been used to cover all steam locomotives used on the mainline in Britain, but also has a particular usage for the three Vale of Rheidol Railway-design locomotives that remained in the ownership of British Rail (BR) after the end of mainline steam traction in August 1968. The locomotives on the Vale of Rheidol Railway were the only steam locomotives ever officially to carry the British Rail corporate blue and the double arrow logo.
The number 98010 was assigned to an locomotive acquired by BR in 1987. This locomotive also worked the Vale of Rheidol and was sold along with the steam locomotives. 98010 was built by the Brecon Mountain Railway, using parts supplied by Baguley-Drewry.
Vale of Rheidol locomotives
These three steam locomotives, numbered 7-9 by the Great Western Railway and British Railways, were the only ones to survive in BR's ownership after the end of mainline steam traction in August 1968. Under TOPS they were allocated Class 98 and were nominally numbered 98007-98009, but these numbers were never actually carried on the locomotives.
Registered steam locomotives
The Class 98 series has also been used for privately owned steam locomotives registered to run on the mainline since 1971. The first two digits are the class designation, in this case 98, the remaining three digits are allocated as follows:
The third digit represents the power classification, which was |
https://en.wikipedia.org/wiki/Crystal%20Lakes | Crystal Lakes may refer to:
Crystal Lakes, Missouri, United States
Crystal Lakes, New Jersey, United States
Crystal Lakes, Ohio, United States
See also
Crystal Lake (disambiguation) |
https://en.wikipedia.org/wiki/Electroneuronography | Electroneuronography or electroneurography (ENoG) is a neurological non-invasive test used to study the facial nerve in cases of muscle weakness in one side of the face (Bell's palsy). The technique of electroneuronography was first used by Esslen and Fisch in 1979 to describe a technique that examines the integrity and conductivity of peripheral nerves. In modern use, ENoG is used to describe study of the facial nerve, while the term nerve conduction study is employed for other nerves.
It consists of a brief electrical stimulation of the nerve in one point underneath the skin, and at the same time recording the electrical activity (compound action potentials) at another point of the nerve's trajectory in the body. The response is displayed in a cathode ray tube (CRT) or through the video monitor of a computer. The stimulation as well as the recording are carried out by disc electrodes taped to the skin, and the technician may use electrically conducting gel or paste to bolster the signals being input and output. Alternatively, the recording electrodes may also be used to pick up the electrical activity of a muscle innervated by that nerve. In such instances electroneuronography is closely related to electromyography.
It is performed by an audiologist, who carries out tests to compare the two sides of the face.
The stimulation electrode is located at the stylomastoid foramen and the recording electrode is located near the nasolabial fold. The ENoG test is the only obje |
https://en.wikipedia.org/wiki/Pendulum%20Instruments | Pendulum Instruments is a line of scientific instruments for high-resolution time and frequency measurements.
Pendulum was originally created in the 1960s as the Philips time and frequency competence center. After 30 years of existence within Philips, it was spun off from 1998 but continued to sell Philips-branded instruments for another two years before starting to sell instruments under its own brand name.
A Russian subsidiary was established in 2004, and in 2005, XL Microwave (an Oakland, CA-based manufacturer of microwave frequency counters and similar equipment) was acquired and transformed into the US branch Pendulum Instruments, Inc.
In 2008, Pendulum became part of the Orolia Group, and in 2009 its operations were combined with another Orolia company, Spectracom to form one global time & frequency systems & services organization operating under the Spectracom umbrella. Pendulum Instruments continues to be a leading brand of test & measurement instruments and are also sold under the Fluke brand name in most parts of the world, and total sales in the specific field are second only to Agilent Technologies.
Pendulum's range of products:
Crystal, OCXO and rubidium-based frequency counters and timers
Frequency references (OCXO and rubidium based, stand-alone as well as GPS disciplined)
Reference frequency distribution systems (coaxial and optical)
Instruments for measuring the stability of synchronization clocks
Notes
External links
Webpage of Pendulum Instruments
|
https://en.wikipedia.org/wiki/Granzyme | Granzymes are serine proteases released by cytoplasmic granules within cytotoxic T cells and natural killer (NK) cells. They induce programmed cell death (apoptosis) in the target cell, thus eliminating cells that have become cancerous or are infected with viruses or bacteria. Granzymes also kill bacteria and inhibit viral replication. In NK cells and T cells, granzymes are packaged in cytotoxic granules along with perforin. Granzymes can also be detected in the rough endoplasmic reticulum, golgi complex, and the trans-golgi reticulum. The contents of the cytotoxic granules function to permit entry of the granzymes into the target cell cytosol. The granules are released into an immune synapse formed with a target cell, where perforin mediates the delivery of the granzymes into endosomes in the target cell, and finally into the target cell cytosol. Granzymes are part of the serine esterase family. They are closely related to other immune serine proteases expressed by innate immune cells, such as neutrophil elastase and cathepsin G.
Granzyme B activates apoptosis by activating caspases (especially caspase-3), which cleaves many substrates, including caspase-activated DNase to execute cell death. Granzyme B also cleaves the protein Bid, which recruits the proteins Bax and Bak to change the membrane permeability of the mitochondria, causing the release of cytochrome c (which is one of the parts needed to activate caspase-9 via the apoptosome), Smac/Diablo and Omi/HtrA2 (which su |
https://en.wikipedia.org/wiki/Ezemvelo%20KZN%20Wildlife | Ezemvelo KZN Wildlife (officially, the KwaZulu-Natal Nature Conservation Board) is a governmental organisation responsible for maintaining wildlife conservation areas and biodiversity in KwaZulu-Natal Province, South Africa. Their headquarters is in Queen Elizabeth Park situated on the northern slopes of Pietermaritzburg, the KwaZulu-Natal provincial capital. Prior to 1994, it was known as the Natal Parks Board.
History
The first known person to provide protection to wildlife in the region was Zulu King Shaka, who prevented excessive hunting of game animals in the Umfolozi River valley in the early 19th century. However King Shaka used this area for his own hunting purposes and cannot be classed as a 'preservationist'.
Voortrekkers, who entered the region now known as KwaZulu-Natal in the early 19th century, also had conservation policies. The Voortrekker leader Piet Retief had rules excluding the unnecessary shooting of game, and veld burning was strictly controlled.
Zulu King Mpande is known to have afforded protection to the Ongoye Forest. He is also said to have issued an edict preventing the killing of large game animals.
The Durban Botanic Garden was founded in 1859, and although founded for studies into economically important exotic plants, soon became a centre for the study of local plants, and ultimately led to realising the importance of protecting areas of natural vegetation.
In 1866, the Natal Government drew up the first game laws at a time when Zululand wa |
https://en.wikipedia.org/wiki/ROAM | Real-time optimally adapting mesh (ROAM) is a continuous level of detail algorithm that optimizes terrain meshes. On modern computers, sometimes it is more effective to send a small amount of unneeded polygons to the GPU, rather than burden the CPU with LOD (Level of Detail) calculations—making algorithms like geomipmapping more effective than ROAM. This technique is used by graphics programmers
in order to produce high quality displays while being able to maintain real-time frame rates. Algorithms such as ROAM exist to provide a control over scene quality versus performance in order to provide HQ scenes while retaining real-time frame rates on hardware. ROAM largely aims toward terrain visualization, but various elements from ROAM are difficult to place within a game system.
To assist regional geological mapping, more abundant and visualized expression forms are highly needs. Thus, the 3D terrain model is adopted as the carrier for the demands in many correlative fields. Based on the regular grid DEM (Digital Elevation Model) in DRGS, ROAM algorithm is applied to create a more dynamic model, which will give consideration to the importance of different features and select correspondence level of detail.
Original Paper
The algorithm was introduced in the paper " ROAMing Terrain: Real-time Optimally Adapting Meshes" appearing in the Proceedings of IEEE Visualization 1997. The authors are
Mark Duchaineau
Murray Wolinsky
David E. Sigeti
Mark C. Miller
Charles Aldrich
Mark B. M |
https://en.wikipedia.org/wiki/Large%20eddy%20simulation | Large eddy simulation (LES) is a mathematical model for turbulence used in computational fluid dynamics. It was initially proposed in 1963 by Joseph Smagorinsky to simulate atmospheric air currents, and first explored by Deardorff (1970). LES is currently applied in a wide variety of engineering applications, including combustion, acoustics, and simulations of the atmospheric boundary layer.
The simulation of turbulent flows by numerically solving the Navier–Stokes equations requires resolving a very wide range of time and length scales, all of which affect the flow field. Such a resolution can be achieved with direct numerical simulation (DNS), but DNS is computationally expensive, and its cost prohibits simulation of practical engineering systems with complex geometry or flow configurations, such as turbulent jets, pumps, vehicles, and landing gear.
The principal idea behind LES is to reduce the computational cost by ignoring the smallest length scales, which are the most computationally expensive to resolve, via low-pass filtering of the Navier–Stokes equations. Such a low-pass filtering, which can be viewed as a time- and spatial-averaging, effectively removes small-scale information from the numerical solution. This information is not irrelevant, however, and its effect on the flow field must be modelled, a task which is an active area of research for problems in which small-scales can play an important role, such as near-wall flows, reacting flows, and multiphase |
https://en.wikipedia.org/wiki/Dorsal%20root%20ganglion | A dorsal root ganglion (or spinal ganglion; also known as a posterior root ganglion) is a cluster of neurons (a ganglion) in a dorsal root of a spinal nerve. The cell bodies of sensory neurons known as first-order neurons are located in the dorsal root ganglia.
The axons of dorsal root ganglion neurons are known as afferents. In the peripheral nervous system, afferents refer to the axons that relay sensory information into the central nervous system (i.e. the brain and the spinal cord).
Structure
The neurons comprising the dorsal root ganglion are of the pseudo-unipolar type, meaning they have a cell body (soma) with two branches that act as a single axon, often referred to as a distal process and a proximal process.
Unlike the majority of neurons found in the central nervous system, an action potential in posterior root ganglion neuron may initiate in the distal process in the periphery, bypass the cell body, and continue to propagate along the proximal process until reaching the synaptic terminal in the posterior horn of spinal cord.
Distal section
The distal section of the axon may either be a bare nerve ending or encapsulated by a structure that helps relay specific information to nerve. Two examples where the nerve ending of the distal process is encapsulated as such are, Meissner's corpuscles, which render the distal processes of mechanosensory neurons sensitive to stroking only, and Pacinian corpuscles, which make neurons more sensitive to vibration.
Location
The |
https://en.wikipedia.org/wiki/Dry%20cell | A dry cell is a type of electric battery, commonly used for portable electrical devices. Unlike wet cell batteries, which have a liquid electrolyte, dry cells use an electrolyte in the form of a paste, and are thus less susceptible to leakage.
The dry cell was developed in 1886 by the German scientist Carl Gassner, after development of wet zinc–carbon batteries by Georges Leclanché in 1866. A type of dry cell was also developed by the Japanese inventor Sakizō Yai in 1887.
History
Many experimenters tried to immobilize the electrolyte of an electrochemical cell to make it more convenient to use. The Zamboni pile of 1812 is a high-voltage dry battery but capable of delivering only minute currents. Various experiments were made with cellulose, sawdust, spun glass, asbestos fibers, and gelatine.
In 1886, Carl Gassner obtained a German patent (No. 37,758) on a variant of the (wet) Leclanché cell, which came to be known as the dry cell because it did not have a free liquid electrolyte. Instead, the ammonium chloride was mixed with Plaster of Paris to create a paste, with a small amount of zinc chloride added in to extend the shelf life. The manganese dioxide cathode was dipped in this paste, and both were sealed in a zinc shell, which also acts as the anode. In November 1887, he obtained for the same device. A dry-battery was invented in Japan during the Meiji Era in 1887. The inventor was Sakizō Yai. However, Yai didn't have enough money to file the patent, the first patent |
https://en.wikipedia.org/wiki/Air%20cylinder | Air cylinder may refer to:
A gas cylinder used to store compressed air
Pneumatic cylinder, a mechanical device used to impart a force from a fluid, such as air |
https://en.wikipedia.org/wiki/British%20Rail%20Classes%20316%20and%20457 | Class 316 and Class 457 were TOPS classifications assigned to a single electric multiple unit (EMU) at different stages of its use as a prototype for the Networker series.
Project
In the late 1980s, the Network SouthEast division of British Rail, which operated the railway network in South East England, started to develop a new standard train, known as the Networker. To test out the technical arrangements for the Networker, a test train was used, converted from former Class 210 carriages, which were built in 1982 by Derby Litchurch Lane Works as prototype 'Second Generation' Diesel Electric Multiple Unit (DEMU), but were withdrawn after a few years.
Class 457
Initially the test unit was formed for trials on the system of the Southern Region, and was numbered 457001. As with all Southern Region electric multiple units only the last four digits of the unit number were actually carried.
The unit formation was:
Class 316
Later, the unit was altered to undertake trials on the overhead line system used on electrified lines north of the River Thames. The unit was renumbered as a Class 316 unit, number 316999. To enable it to work on the AC electrification, a pantograph trailer from a Class 313 unit 313034 was inserted into the set, replacing one of the intermediate trailers. This spare vehicle (no. 67400) has since been incorporated into a Class 455/9 DC suburban unit, replacing a damaged Trailer Second Open (TSO) vehicle.
The unit formation was:
Preservation
After the AC tri |
https://en.wikipedia.org/wiki/Cataract%20surgery | Cataract surgery, which is also called lens replacement surgery, is the removal of the natural lens (also called the "crystalline lens") of the human eye that has developed a cataract, an opaque or cloudy area. The eye's natural lens is usually replaced with an artificial intraocular lens (IOL).
Over time, metabolic changes of the crystalline lens fibres lead to the development of a cataract, causing impairment or loss of vision. Some infants are born with congenital cataracts, and environmental factors may lead to cataract formation. Early symptoms may include strong glare from lights and small light sources at night, and reduced visual acuity at low light levels.
During cataract surgery, the cloudy natural lens is removed, either by emulsification in place or by cutting it out. An IOL is usually implanted in its place to restore useful focus. Cataract surgery is generally performed by an ophthalmologist in an out-patient setting at a surgical centre or hospital. Local anaesthesia is normally used; the procedure is usually quick, and causes little or no pain and minor discomfort to the patient. Recovery sufficient for most daily activities usually takes place in days and full recovery about a month.
Well over 90% of operations are successful in restoring useful vision, and there is a low complication rate. Day care, high-volume, minimally invasive, small-incision phacoemulsification with quick post-operative recovery has become the standard of care in cataract surgery in |
https://en.wikipedia.org/wiki/Boracite | Boracite is a magnesium borate mineral with formula: Mg3B7O13Cl. It occurs as blue green, colorless, gray, yellow to white crystals in the orthorhombic - pyramidal crystal system. Boracite also shows pseudo-isometric cubical and octahedral forms. These are thought to be the result of transition from an unstable high temperature isometric form on cooling. Penetration twins are not unusual. It occurs as well formed crystals and dispersed grains often embedded within gypsum and anhydrite crystals. It has a Mohs hardness of 7 to 7.5 and a specific gravity of 2.9. Refractive index values are nα = 1.658 - 1.662, nβ = 1.662 - 1.667 and nγ = 1.668 - 1.673. It has a conchoidal fracture and does not show cleavage. It is insoluble in water (not to be confused with borax, which is soluble in water).
Boracite is typically found in evaporite sequences associated with gypsum, anhydrite, halite, sylvite, carnallite, kainite and hilgardite. It was first described in 1789 for specimens from its type locality of Kalkberg hill, Lüneburg, Lower Saxony, Germany. It is also found near Sussex, New Brunswick.
The name is derived from its boron content (19 to 20% boron by mass).
See also
Classification of minerals
List of minerals
References
Palache, C., H. Berman, and C. Frondel (1951) Dana’s system of mineralogy, 7th edition, v. II, pp.378–381.
Tektoborates
Magnesium minerals
Orthorhombic minerals
Minerals in space group 29
Borate chlorides |
https://en.wikipedia.org/wiki/Feature%20selection | Feature selection is the process of selecting a subset of relevant features (variables, predictors) for use in model construction. Stylometry and DNA microarray analysis are two cases where feature selection is used. It should be distinguished from feature extraction.
Feature selection techniques are used for several reasons:
simplification of models to make them easier to interpret by researchers/users,
shorter training times,
to avoid the curse of dimensionality,
improve data's compatibility with a learning model class,
encode inherent symmetries present in the input space.
The central premise when using a feature selection technique is that the data contains some features that are either redundant or irrelevant, and can thus be removed without incurring much loss of information. Redundant and irrelevant are two distinct notions, since one relevant feature may be redundant in the presence of another relevant feature with which it is strongly correlated.
Feature extraction creates new features from functions of the original features, whereas feature selection returns a subset of the features. Feature selection techniques are often used in domains where there are many features and comparatively few samples (or data points).
Introduction
A feature selection algorithm can be seen as the combination of a search technique for proposing new feature subsets, along with an evaluation measure which scores the different feature subsets. The simplest algorithm is to test each p |
https://en.wikipedia.org/wiki/Basal%20lamina | The basal lamina is a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits. It is often incorrectly referred to as the basement membrane, though it does constitute a portion of the basement membrane. The basal lamina is visible only with the electron microscope, where it appears as an electron-dense layer that is 20–100 nm thick (with some exceptions that are thicker, such as basal lamina in lung alveoli and renal glomeruli).
Structure
The layers of the basal lamina ("BL") and those of the basement membrane ("BM") are described below:
Anchoring fibrils composed of type VII collagen extend from the basal lamina into the underlying reticular lamina and loop around collagen bundles. Although found beneath all basal laminae, they are especially numerous in stratified squamous cells of the skin.
These layers should not be confused with the lamina propria, which is found outside the basal lamina.
Basement membrane
The basement membrane is visible under light microscopy. Electron microscopy shows that the basement membrane consists of three layers: the lamina lucida (electron-lucent), lamina densa (electron-dense), and lamina fibro-reticularis (electron-lucent).
The lamina densa was formerly called the “basal lamina”. The terms “basal lamina” and “basement membrane” were often used interchangeably, until it was realised that all three layers seen with the electron microscope constituted the single layer seen with the light microscope. Th |
https://en.wikipedia.org/wiki/Itoh%E2%80%93Tsujii%20inversion%20algorithm | The Itoh–Tsujii inversion algorithm is used to invert elements in a finite field. It was introduced in 1988, first over GF(2m) using the normal basis representation of elements, however, the algorithm is generic and can be used for other bases, such as the polynomial basis. It can also be used in any finite field GF(pm).
The algorithm is as follows:
Input: A ∈ GF(pm)
Output: A−1
r ← (pm − 1)/(p − 1)
compute Ar−1 in GF(pm)
compute Ar = Ar−1 · A
compute (Ar)−1 in GF(p)
compute A−1 = (Ar)−1 · Ar−1
return A−1
This algorithm is fast because steps 3 and 5 both involve operations in the subfield GF(p). Similarly, if a small value of p is used, a lookup table can be used for inversion in step 4. The majority of time spent in this algorithm is in step 2, the first exponentiation. This is one reason why this algorithm is well suited for the normal basis, since squaring and exponentiation are relatively easy in that basis.
See also
Finite field arithmetic
References
T. Itoh and S. Tsujii. A Fast Algorithm for Computing Multiplicative Inverses in GF(2m) Using Normal Bases. Information and Computation, 78:171–177, 1988.
Finite fields
Computational number theory |
https://en.wikipedia.org/wiki/Pyromorphite | Pyromorphite is a mineral species composed of lead chlorophosphate: Pb5(PO4)3Cl, sometimes occurring in sufficient abundance to be mined as an ore of lead. Crystals are common, and have the form of a hexagonal prism terminated by the basal planes, sometimes combined with narrow faces of a hexagonal pyramid. Crystals with a barrel-like curvature are not uncommon. Globular and reniform masses are also found. It is part of a series with two other minerals: mimetite (Pb5(AsO4)3Cl) and vanadinite (Pb5(VO4)3Cl), the resemblance in external characters is so close that, as a rule, it is only possible to distinguish between them by chemical tests. They were formerly confused under the names green lead ore and brown lead ore (German: Grünbleierz and Braunbleierz).
The phosphate was first distinguished chemically by M. H. Klaproth in 1784,<ref>{{cite web | url = http://tw.strahlen.org/typloc/pyromorphit.html | title= Entdeckung von Pyromorphit (Discovery of pyromorphite) | author = Dr. Thomas Witzke | language = de}}</ref> and it was named pyromorphite by J. F. L. Hausmann in 1813. The name is derived from the Greek for pyr (fire) and morfe (form) due to its crystallization behavior after being melted. Paecilomyces javanicus is a mold collected from a lead-polluted soil that is able to form biominerals of pyromorphite.
Properties and isomorphism
The color of the mineral is usually some bright shade of green, yellow or brown, and the luster is resinous. The hardness is 3.5 to 4, and t |
https://en.wikipedia.org/wiki/Stochastic%20gradient%20descent | Stochastic gradient descent (often abbreviated SGD) is an iterative method for optimizing an objective function with suitable smoothness properties (e.g. differentiable or subdifferentiable). It can be regarded as a stochastic approximation of gradient descent optimization, since it replaces the actual gradient (calculated from the entire data set) by an estimate thereof (calculated from a randomly selected subset of the data). Especially in high-dimensional optimization problems this reduces the very high computational burden, achieving faster iterations in exchange for a lower convergence rate.
While the basic idea behind stochastic approximation can be traced back to the Robbins–Monro algorithm of the 1950s, stochastic gradient descent has become an important optimization method in machine learning.
Background
Both statistical estimation and machine learning consider the problem of minimizing an objective function that has the form of a sum:
where the parameter that minimizes is to be estimated. Each summand function is typically associated with the -th observation in the data set (used for training).
In classical statistics, sum-minimization problems arise in least squares and in maximum-likelihood estimation (for independent observations). The general class of estimators that arise as minimizers of sums are called M-estimators. However, in statistics, it has been long recognized that requiring even local minimization is too restrictive for some problems of maxim |
https://en.wikipedia.org/wiki/Converter | Converter may refer to:
Electromagnetics
Frequency converter
Voltage converter, another name for
Electromagnetic transformer
Switched-mode power supply
DC-to-DC converter
Power inverter (DC to AC)
Solar inverter
Electronics
Digital-to-analog converter
Analog-to-digital converter
"Frequency-to-Voltage converter" (F-V converter), a frequency detector for voltage-controlled guitar synthesizer
A combination local oscillator and mixer stage in a superheterodyne receiver
"Converter", an alternate name for a remote control
In television
Cable converter box, an electronic device use in cable television systems
Digital television adapter, sometimes known as a "converter box"
Information technology
Low-noise converter, in communications
Scan conversion between video formats
File format converter, for converting between various file formats
Currency converter, a piece of software for converting one currency into another
Metallurgy
Converter (metallurgy), a device for metallurgical smelting
Bessemer converter
Manhès-David converter
see also basic oxygen steelmaking
Vehicles, automobiles
Catalytic converter, in automobiles
Autogas converter, part of an automotive LPG system, also known as a vaporiser or pressure reducer
Other uses
Torque converter, a fluid coupling to transfer torque
Fountain pen converter, a removable filling mechanism for fountain pens
Unit converter, for converting between different units of measurement
Converters (industry), companies that create end products |
https://en.wikipedia.org/wiki/Predicable | Predicable (Lat. praedicabilis, that which may be stated or affirmed, sometimes called quinque voces or five words) is, in scholastic logic, a term applied to a classification of the possible relations in which a predicate may stand to its subject. It is not to be confused with 'praedicamenta', the scholastics' term for Aristotle's ten Categories.
The list given by the scholastics and generally adopted by modern logicians is based on development of the original fourfold classification given by Aristotle (Topics, a iv. 101 b 17-25): definition (horos), genus (genos), property (idion), and accident (sumbebekos). The scholastic classification, obtained from Boethius's Latin version of Porphyry's Isagoge, modified Aristotle's by substituting species (eidos) and difference (diaphora) for definition. Both classifications are of universals, concepts or general terms, proper names of course being excluded. There is, however, a radical difference between the two systems. The standpoint of the Aristotelian classification is the predication of one universal concerning another. The Porphyrian, by introducing species, deals with the predication of universals concerning individuals (for species is necessarily predicated of the individual), and thus created difficulties from which the Aristotelian is free (see below).
The Aristotelian treatment considered:
The definition of anything is the statement of its essence (Arist. τὸ τί ἦν εἶναι), i.e., that which makes it what it is: e.g |
https://en.wikipedia.org/wiki/Overlapping%20subproblems | In computer science, a problem is said to have overlapping subproblems if the problem can be broken down into subproblems which are reused several times or a recursive algorithm for the problem solves the same subproblem over and over rather than always generating new subproblems.
For example, the problem of computing the Fibonacci sequence exhibits overlapping subproblems. The problem of computing the nth Fibonacci number F(n), can be broken down into the subproblems of computing F(n − 1) and F(n − 2), and then adding the two. The subproblem of computing F(n − 1) can itself be broken down into a subproblem that involves computing F(n − 2). Therefore, the computation of F(n − 2) is reused, and the Fibonacci sequence thus exhibits overlapping subproblems.
A naive recursive approach to such a problem generally fails due to an exponential complexity. If the problem also shares an optimal substructure property, dynamic programming is a good way to work it out.
Fibonacci sequence example in C
Consider the following C code:
#include <stdio.h>
#define N 5
static int fibMem[N];
int fibonacci(int n) {
int r = 1;
if (n > 2) {
r = fibonacci(n - 1) + fibonacci(n - 2);
}
fibMem[n - 1] = r;
return r;
}
void printFibonacci() {
int i;
for (i = 1; i <= N; i++) {
printf("fibonacci(%d): %d\n", i, fibMem[i - 1]);
}
}
int main(void) {
fibonacci(N);
printFibonacci();
return 0;
}
/* Output:
fibonacci(1): 1
fibonacci(2): 1
fibonacci(3): 2
|
https://en.wikipedia.org/wiki/Frontlight | A frontlight is a means of illuminating a display device, usually a liquid crystal display (LCD), which would otherwise be viewed in ambient light. This improves its performance in poor lighting conditions.
An LCD presents an image by absorbing some light passing through it. When an electric field is applied across the crystal, it changes the passing light so it will not pass through a polarization filter. This allows LCDs to operate at low power, as no energy needs to be spent generating light. Many battery-operated electronic devices, including most calculators and other devices use unilluminated LCDs.
An unilluminated LCD must be lit from the front. To use ambient light, the liquid crystal itself is sandwiched between a polarization filter and a reflective surface. The mirror makes the display opaque so it cannot be illuminated from the back. Most often a light source is placed around the perimeter of the LCD.
Frontlights are relatively uncommon. Electroluminescent lights present a reflective surface when turned off. This allows for a backlit display which can also be used with ambient light. Such backlights are popular in digital watches. The monochromatic light from an electroluminescent source does not work well with color displays, however. An incandescent frontlight was therefore a popular accessory for the Nintendo Game Boy Color.
Devices using a frontlight
GP32 FLU (2002)
Game Boy Advance SP (2003)
Kindle Paperwhite (2013)
See also
LCD
Backlight
Liquid crystal |
https://en.wikipedia.org/wiki/Knight%20shift | The Knight shift is a shift in the nuclear magnetic resonance (NMR) frequency of a paramagnetic
substance first published in 1949 by the UC Berkeley physicist Walter D. Knight.
For an ensemble of N spins in a magnetic induction field , the nuclear Hamiltonian for the Knight shift is expressed in Cartesian form by:
, where for the ith spin is the gyromagnetic ratio, is a vector of the Cartesian nuclear angular momentum operators, the
matrix is a second-rank tensor similar to the chemical shift shielding tensor.
The Knight shift refers to the relative shift K in NMR frequency for atoms in a metal (e.g. sodium) compared with the same atoms in a nonmetallic environment (e.g. sodium chloride). The observed shift reflects the local magnetic field produced at the sodium nucleus by the magnetization of the conduction electrons. The average local field in sodium augments the applied resonance field by approximately one part per 1000. In nonmetallic sodium chloride the local field is negligible in comparison.
The Knight shift is due to the conduction electrons in metals. They introduce an "extra" effective field at the nuclear site, due to the spin orientations of the conduction electrons in the presence of an external field. This is responsible for the shift observed in the nuclear magnetic resonance. The shift comes from two sources, one is the Pauli paramagnetic spin susceptibility, the other is the s-component wavefunctions at the nucleus.
Depending on the electronic stru |
https://en.wikipedia.org/wiki/Class%202 | Class 2 may refer to:
BR Standard Class 2 2-6-0, British steam locomotive
BR Standard Class 2 2-6-2T, British steam locomotive
Class 2 Touring Cars, FIA classification for cars in auto racing
Classes of U.S. Senators
L&YR Class 2, British 4-4-0 steam locomotive designed by William Barton Wright
L&YR Class 2 (Aspinall), British 4-4-0 steam locomotive designed by John Aspinall
NSB El 2, Norwegian electric locomotive
NSB Di 2, Norwegian diesel locomotive
SCORE Class 2, off-road racing vehicles
A contribution class in the National Insurance system in the UK
The second class in terms of hiking difficulty in the Yosemite Decimal System
A speed class rating for Secure Digital cards
A class in the electrical Appliance classes
See also
Class II (disambiguation)
Class 02 (disambiguation)
Type 2 (disambiguation)
de:Klasse 2 |
https://en.wikipedia.org/wiki/Jacques%20Charles%20Fran%C3%A7ois%20Sturm | Jacques Charles François Sturm (29 September 1803 – 15 December 1855) was a French mathematician, who made a significant addition to equation theory with his work, the Sturm's theorem.
Early life
Sturm was born in Geneva, Switzerland in 1803. The family of his father, Jean-Henri Sturm, had emigrated from Strasbourg around 1760—about 50 years before Charles-François's birth. His mother's name was Jeanne-Louise-Henriette Gremay.
In 1818, he started to follow the lectures of the academy of Geneva. The death of his father forced Sturm to give lessons to children of the rich in order to support his own family the following year. In 1823, he became tutor to the son of Madame de Staël.
At the end of 1823, Sturm stayed in Paris for a short time following the family of his student. He resolved, with his school-fellow Jean-Daniel Colladon, to try his fortune in Paris, and obtained employment on the Bulletin universel.
Discovery
In 1829, he discovered the theorem that bears his name, and concerns real-root isolation, that is the determination of the number and the localization of the real roots of a polynomial.
Work
Sturm benefited from the 1830 revolution, as his Protestant faith ceased to be an obstacle to employment in public high schools. At the end of 1830, he was thus appointed as a professor of Mathématiques Spéciales at the collège Rollin.
He was chosen a member of the Académie des Sciences in 1836, filling the seat of André-Marie Ampère. Sturm became répétiteur in 18 |
https://en.wikipedia.org/wiki/Furnace%20anneal | Furnace annealing is a process used in semiconductor device fabrication which consist of heating multiple semiconductor wafers in order to affect their electrical properties. Heat treatments are designed for different effects. Wafers can be heated in order to activate dopants, change film to film or film to wafer substrate interfaces, densify deposited films, change states of grown films, repair damage from implants, move dopants or drive dopants from one film into another or from a film into the wafer substrate. During ion implantation process, the crystal substrate is damaged due to bombardment with high energy ions. The damage caused can be repaired by subjecting the crystal to high temperature. This process is called annealing. Furnace anneals may be integrated into other furnace processing steps, such as oxidations, or may be processed on their own.
Furnace anneals are performed by equipment especially built to heat semiconductor wafers. Furnaces are capable of processing many wafers at a time but each process can last between several hours and a day. Increasingly, furnace anneals are being supplanted by Rapid Thermal Anneal (RTA) or Rapid Thermal Processing (RTP). This is due to the relatively long thermal cycles of furnaces that causes the dopants that are being activated, especially boron, to diffuse farther than is intended. RTP or RTA fixes this by having thermal cycles for each wafer that is of the order of minutes rather than hours for furnace anneals.
Equipme |
https://en.wikipedia.org/wiki/Hodierna%20of%20Jerusalem | Hodierna of Jerusalem ( 1110 – 1164) was a countess consort of Tripoli through her marriage to Raymond II of Tripoli, and regent of the County of Tripoli during the minority of her son from 1152 until 1155.
Early life
She was the daughter of Baldwin II of Jerusalem and the Armenian noblewoman Morphia. Hodierna was the third of four daughters; her older sisters were Melisende, who succeeded their father, and Alice, who aspired to rule Antioch, and her younger sister was Ioveta, abbess of Bethany.
Countess of Tripoli
Hodierna married Raymond II of Tripoli in about 1135. Hodierna was close to her sisters: she may have asked Melisende to arrange for the assassination of Alphonse I of Toulouse, son of Raymond IV of Toulouse, in 1148, when Alphonse came to claim the County of Tripoli. Hodierna supported Melisende in her struggle with her son Baldwin III in 1150-52. Melisende ended up on the losing side by 1152, but she was given a small fief to rule in Nablus, where she and Hodierna were able to influence the election of the Latin Patriarch.
Regency
In 1152, Hodierna was in the midst of a dispute with her husband Raymond II of Tripoli. Hodierna, like her sisters, was very independent, but Raymond was a jealous man and kept her in seclusion. There were even rumours that their daughter Melisende (named after the queen) was fathered by a different man. Her sister Melisende and her nephew Baldwin came north to intervene. Hodierna and Raymond agreed to reconcile, but it was also dec |
https://en.wikipedia.org/wiki/Zeta%20potential | Zeta potential is the electrical potential at the slipping plane. This plane is the interface which separates mobile fluid from fluid that remains attached to the surface.
Zeta potential is a scientific term for electrokinetic potential in colloidal dispersions. In the colloidal chemistry literature, it is usually denoted using the Greek letter zeta (ζ), hence ζ-potential. The usual units are volts (V) or, more commonly, millivolts (mV). From a theoretical viewpoint, the zeta potential is the electric potential in the interfacial double layer (DL) at the location of the slipping plane relative to a point in the bulk fluid away from the interface. In other words, zeta potential is the potential difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle.
The zeta potential is caused by the net electrical charge contained within the region bounded by the slipping plane, and also depends on the location of that plane. Thus, it is widely used for quantification of the magnitude of the charge. However, zeta potential is not equal to the Stern potential or electric surface potential in the double layer, because these are defined at different locations. Such assumptions of equality should be applied with caution. Nevertheless, zeta potential is often the only available path for characterization of double-layer properties.
The zeta potential is an important and readily measurable indicator of the stability of colloidal dispersions |
https://en.wikipedia.org/wiki/Astrochicken | Astrochicken is the name given to a thought experiment expounded by theoretical physicist Freeman Dyson. An Astrochicken is a small, one-kilogram spacecraft, a self-replicating automaton that could explore space more efficiently than a crewed craft could due to its innovative mix of technology.
Description
In his book Disturbing the Universe (1979), Dyson contemplated how humanity could build a small, self-replicating automaton that could explore space more efficiently than a crewed craft could. He attributed the general idea to John von Neumann, based on a lecture von Neumann gave in 1948 titled The General and Logical Theory of Automata. Dyson expanded on von Neumann's automata theories and added a biological component to them.
Astrochicken, Dyson explained, would be a one-kilogram spacecraft unlike any before it. It would be a creation of the intersection of biology, artificial intelligence and modern microelectronics—a blend of organic and electronic components. Astrochicken would be launched by a conventional spacecraft into space, like an egg being laid into space. Astrochicken would then hatch and start growing a solar-energy collector. The solar collector would feed an ion drive engine that would power the craft. Once Astrochicken entered a planet's vicinity, it would collect material from the moons and rings of the planet, taking in nutrients. It could land and take off using an auxiliary chemical rocket similar to that used by bombardier beetles. It would periodi |
https://en.wikipedia.org/wiki/Islam%20in%20Thailand | Islam is a minority faith in Thailand, with statistics suggesting 4.9% of the population are Muslim. Figures as high as 5% of Thailand's population have also been mentioned. A 2023 Pew Research Center survey gave 7%.
Most Thai Muslims are Sunni Muslims, although Thailand has a diverse population that includes immigrants from around the world.
Demographics and geography
Popular opinion seems to hold that a vast majority of the country's Muslims are found in Thailand's four southernmost provinces of Satun, Yala, Pattani and Narathiwat, where they make up majority of the population. However, the Thai Ministry of Foreign Affairs' research indicates that only 18 percent of Thai Muslims live in those four provinces. There are also significant minority of Muslims in other southern provinces such as Krabi, Trang, Phatthalung and Phuket. In Bangkok, large Muslim populations maybe found in districts such as Nong Chok, Min Buri and Bang Rak.
According to the National Statistics Office, in 2015 census, Muslims in Southern Thailand made up 24 percent of the total population, while less than three percent in other parts of the country.
History
Muslim merchant communities resided in Thailand as early as the 9th century.
In early modern Thailand, Muslims from the Coromandel Coast served as eunuchs in the Thai palace and court. Thailand, as Siam, was known for religious tolerance, and there were Muslims working for the Siamese Royal Governments throughout the eras. This culture of tol |
https://en.wikipedia.org/wiki/YAM%20%28software%29 | YAM (short for Yet Another Mailer) is a MIME-compliant E-mail client written for AmigaOS and derivative operating systems. Originally created by Marcel Beck, it currently supports multiple user accounts, encrypted communications via OpenSSL and PGP, unlimited hierarchical folders and filters, a configurable GUI based on MUI, extensive ARexx support for automating tasks, and most of the features to be expected in modern E-mail clients.
History
The initial release from 1995 arrived when the Internet was still something very new for the average Amiga user. However, as time passed and further 1.x updates were released, YAM became quickly popular thanks to its simplicity and comprehensible user interface at a time when competing products were either German only (MicroDot), required a shareware fee (MicroDot-II) or used a less intuitive GUI in comparison, such as Thor.
The early YAM 1.x series, while very usable for the most part, was relatively basic and spartan in terms of functionality. It wasn't until 2.0 that finally the program started showing its full potential, featuring a major redesign of the user interface and a plethora of new features which turned it into the de facto standard Amiga E-mail client ever since.
Released in late 2000, YAM 2.2 was the last update from Marcel Beck, who ceased Amiga development but also released the sources under the GNU GPL-2.0-or-later. A group of Amiga developers then teamed up to coordinate and resume development, and finally in 2004 |
https://en.wikipedia.org/wiki/Ostwald | Ostwald may refer to:
Friedrich Wilhelm Ostwald, the physico-chemist (awarded the Nobel Prize in Chemistry, 1909)
Ostwald's rule of polymorphism: in general, the least stable polymorph crystallizes first
The Ostwald Process, a synthesis method for making nitric acid from ammonia
Ostwald ripening, a crystallization effect
Ostwald color system
Wolfgang Ostwald, chemist and biologist, son of Friedrich Wilhelm Ostwald. He studied colloids
Martin Ostwald, a German-American classical scholar
Ostwald (crater), a crater on the far side of the Moon
Ostwald, Bas-Rhin, a commune in the Bas-Rhin département in France
See also
Oswald (disambiguation)
Ozwald Boateng |
https://en.wikipedia.org/wiki/Coagulation%20factor%20VII | Coagulation factor VII (, formerly known as proconvertin) is one of the proteins that causes blood to clot in the coagulation cascade, and in humans is coded for by the gene F7. It is an enzyme of the serine protease class. Once bound to tissue factor released from damaged tissues, it is converted to factor VIIa (or blood-coagulation factor VIIa, activated blood coagulation factor VII), which in turn activates factor IX and factor X.
Using genetic recombination a recombinant factor VIIa (eptacog alfa) (trade names include NovoSeven) has been approved by the FDA for the control of bleeding in hemophilia. It is sometimes used unlicensed in severe uncontrollable bleeding, although there have been safety concerns. A biosimilar form of recombinant activated factor VII (AryoSeven) is also available, but does not play any considerable role in the market.
In April 2020, the US FDA approved a new rFVIIa product, eptacog beta (SEVENFACT), the first bypassing agent (BPA) approved in more than 2 decades. As an rFVIIa product, eptacog beta works in a complex with tissue factor to activate factor X to Xa, thereby bypassing FVIII and FIX. The activation of Factor X to Xa initiates the coagulation cascade’s common pathway, leading to clot formation at the site of hemorrhage. Activated FVII binds to endothelial protein C receptor (EPCR), which enhances hemostasis.14 One study showed that eptacog beta binds to EPCR with 25% to 30% more affinity than eptacog alfa, displacing protein C from E |
https://en.wikipedia.org/wiki/Patience%20sorting | In computer science, patience sorting is a sorting algorithm inspired by, and named after, the card game patience. A variant of the algorithm efficiently computes the length of a longest increasing subsequence in a given array.
Overview
The algorithm's name derives from a simplified variant of the patience card game. The game begins with a shuffled deck of cards. The cards are dealt one by one into a sequence of piles on the table, according to the following rules.
Initially, there are no piles. The first card dealt forms a new pile consisting of the single card.
Each subsequent card is placed on the leftmost existing pile whose top card has a value greater than or equal to the new card's value, or to the right of all of the existing piles, thus forming a new pile.
When there are no more cards remaining to deal, the game ends.
This card game is turned into a two-phase sorting algorithm, as follows. Given an array of elements from some totally ordered domain, consider this array as a collection of cards and simulate the patience sorting game. When the game is over, recover the sorted sequence by repeatedly picking off the minimum visible card; in other words, perform a -way merge of the piles, each of which is internally sorted.
Analysis
The first phase of patience sort, the card game simulation, can be implemented to take comparisons in the worst case for an -element input array: there will be at most piles, and by construction, the top cards of the piles form an i |
https://en.wikipedia.org/wiki/Body%20for%20Life | Body for Life (BFL) is a 12-week nutrition and exercise program, and also an annual physique transformation competition. The program utilizes a low-fat high-protein diet. It was created by Bill Phillips, a former competitive bodybuilder and previous owner of EAS, a manufacturer of nutritional supplements.
It has been popularized by a bestselling book of the same name.
Medical experts have described Body for Life as being effective, if difficult to follow. It has sometimes been described as a fad diet, but this criticism is not universal.
Exercise
The human body adapts itself to changes in nutritional intake. If the calorie intake is reduced, the body responds by slowing down its metabolism, and by burning muscle in preference to fat. This reduces the metabolism long-term. When the diet comes to an end and normal calorie intake is restored, the individual starts to gain weight even faster than before. This is known as yo-yo dieting. Diets that focus exclusively on calorie reduction often fail in this way.
With these concerns in mind, Body for Life addresses energy expenditure (i.e. exercise) in addition to energy input. For best results, Body for Life holds that this exercise should include weight training to build skeletal muscle and increase the metabolism over the long term. This also helps to maximise the energy expenditure and fat loss from aerobic exercise.
Body for Life's exercise program is more complicated than its diet program. It suggests exercising six days |
https://en.wikipedia.org/wiki/Fugacity | In chemical thermodynamics, the fugacity of a real gas is an effective partial pressure which replaces the mechanical partial pressure in an accurate computation of chemical equilibrium. It is equal to the pressure of an ideal gas which has the same temperature and molar Gibbs free energy as the real gas.
Fugacities are determined experimentally or estimated from various models such as a Van der Waals gas that are closer to reality than an ideal gas. The real gas pressure and fugacity are related through the dimensionless fugacity coefficient .
For an ideal gas, fugacity and pressure are equal and so . Taken at the same temperature and pressure, the difference between the molar Gibbs free energies of a real gas and the corresponding ideal gas is equal to .
The fugacity is closely related to the thermodynamic activity. For a gas, the activity is simply the fugacity divided by a reference pressure to give a dimensionless quantity. This reference pressure is called the standard state and normally chosen as 1 atmosphere or 1 bar.
Accurate calculations of chemical equilibrium for real gases should use the fugacity rather than the pressure. The thermodynamic condition for chemical equilibrium is that the total chemical potential of reactants is equal to that of products. If the chemical potential of each gas is expressed as a function of fugacity, the equilibrium condition may be transformed into the familiar reaction quotient form (or law of mass action) except that the press |
https://en.wikipedia.org/wiki/Shotgun%20%28disambiguation%29 | A shotgun is a type of firearm.
Sawed-off shotgun
Shotgun may also refer to:
Science and technology
Shotgun hill climbing, a type of mathematical optimization algorithm in computer science
Shotgun house, a type of narrow, rectangular house
Shotgun sequencing, a method of sequencing DNA
Shotgunning (cold reading), a "mind-reading" technique
Shotgun mic, a type of microphone with a long barrel
Shotgun debugging or shotgunning, a technique in system troubleshooting, debugging, or repair
Shotgun Software, a project management software for creative studios owned by Autodesk
Slang
Riding shotgun, a passenger sitting beside the driver in a car or other vehicle
Shotgun wedding, a hasty wedding due to unplanned pregnancy
Shotgunning, a method for rapidly drinking beer out of a can by punching a hole in it
to shotgun weed or a joint, when one person forces marijuana smoke into the mouth of another person
Sport
Shotgun (shooting sports), a shooting sports discipline
Shotgun, nickname ("Escopeta" in Spanish) of Sergio Roitman (born 1979), professional tennis player from Argentina
Shotgun formation, an offensive formation in American football
"The Shotgun", a nickname for snooker player Jamie Cope
WWF Shotgun Saturday Night, a television series
Film and television
Shotgun (1955 film), an American Western film
Shotgun, 1989 film with Rif Hutton
Shotgun, retitled After Everything, a 2018 American comedy-drama film
"Shotgun" (Breaking Bad), a season four episode of Breaking Bad
Liter |
https://en.wikipedia.org/wiki/AMD%20%28disambiguation%29 | AMD (Advanced Micro Devices) is an American semiconductor manufacturer.
AMD may also refer to:
Science/technology
Acid mine drainage
Age-related macular degeneration of the eye
Algorithmic mechanism design, a field of economics
AMD64 CPU architecture
AMD-65 Automata Módosított Deszantfegyver (Automatic Modified Descent), a Hungarian rifle
Asynchronous module definition, a JavaScript API
amd, the Berkeley Automounter, a daemon on Unix-like operating systems
Alpha-mannosidosis, a lysosomal storage disorder
Business/politics
Aircraft Manufacturing and Design
Alliance for a Democratic Mauritania, or Alliance pour une Mauritanie démocratique, a former political movement
AMD Holdings Inc., an American doll manufacturer
Certified AM Directional Specialist, in broadcasting
Armenian dram, ISO 4217 currency code AMD
Atomic Minerals Directorate for Exploration and Research, Hyderabad, India
American Micro Devices, a 1964–1965 technology company
Arbeitsstelle für Molekularelektronik Dresden, a former name for technology company ZMDI
Other
AMD Academy of Fashion and Design, Germany
A Modest Destiny, a webcomic by Sean Howard
Sardar Vallabhbhai Patel International Airport, Ahmedabad, India, IATA code AMD
See also
`Amd
Amdahl |
https://en.wikipedia.org/wiki/Islam%20in%20the%20United%20Arab%20Emirates | Islam is the official religion of the United Arab Emirates. Of the total population, 76.9% are Muslims as of a 2010 estimate by the Pew Research Center. Although no official statistics are available for the breakdown between Sunni and Shia Muslims among noncitizen residents, media estimates suggest less than 20 percent of the noncitizen Muslim population are Shia.
History
The arrival of envoys from the Islamic prophet Muhammad in 632 heralded the conversion of the region to Islam. After prophet Muhammad's death, one of the major battles of the Ridda Wars was fought at Dibba, to the east coast of the present-day Emirates. The defeat of the non-Muslims, including Laqit bin Malik Al-Azdi, in this battle resulted in the triumph of Islam in the Arabian Peninsula.
The Bani Yas, which today form the Emirate of Abu Dhabi and Emirate of Dubai, traditionally adhere to the Sunni Maliki school of Islamic jurisprudence from the Uyunid dynasty, who spread the Maliki school by the command of Sheikh Abdullah bin Ali Al Uyuni. The four emirates of Sharjah, Umm al-Quwain, Ras al-Khaimah, and Ajman follow the Hanbali school, and the Emirate of Fujairah follows the Shafi'i school.
Structure
The federal General Authority of Islamic Affairs and Endowments (Awqaf) oversee the administration of Sunni mosques, except in Dubai, where they are administered by the Dubai’s Islamic Affairs and Charitable Activities Department (IACAD). The Awqaf distributes weekly guidance to Sunni imams regarding th |
https://en.wikipedia.org/wiki/Fibrinoid%20necrosis | Fibrinoid necrosis is a specific pattern of irreversible, uncontrolled cell death that occurs when antigen-antibody complexes are deposited in the walls of blood vessels along with fibrin. It is common in the immune-mediated vasculitides which are a result of type III hypersensitivity. When stained with hematoxylin and eosin, they appear brightly eosinophilic and smudged.
Diseases
Fibrinoid necrosis is not limited to the immune-mediated vasculitides; many pathologic processes can lead to areas of fibrinoid necrosis. In systemic lupus erythematosus, the dermis is often affected by fluid accumulation and inflammation around the small vessels in the skin, which may show prominent fibrinoid necrosis. Also it's seen in rheumatoid nodules with similar pathology. Also seen in Serum Sickness(Type III hypersensitivity reaction)
References
Histopathology
Necrosis
Cellular processes |
https://en.wikipedia.org/wiki/4-4-2%20%28locomotive%29 | Under the Whyte notation for the classification of steam locomotives by wheel arrangement, represents a configuration of a four-wheeled leading bogie, four powered and coupled driving wheels, and two trailing wheels supporting part of the weight of the boiler and firebox. This allows a larger firebox and boiler than the configuration.
This wheel arrangement is commonly known as the Atlantic type, although it is also sometimes called a Milwaukee or 4-4-2 Milwaukee, after the Milwaukee Road, which employed it in high speed passenger service.
Overview
While the wheel arrangement and type name Atlantic would come to fame in the fast passenger service competition between railroads in the United States by mid-1895, the tank locomotive version of the Atlantic type first made its appearance in the United Kingdom in 1880, when William Adams designed the 1 Class T of the London, Tilbury and Southend Railway (LT&SR).
The is the tank locomotive equivalent of a 4-4-0 American type tender locomotive, but with the frame extended to allow for a fuel bunker behind the cab. This necessitated the addition of a trailing truck to support the additional weight at the rear end of the locomotive. As such, the tank version of the wheel arrangement appeared earlier than the tender version.
The tender version of the originated in the United States of America, evolving from the less stable 2-4-2 Columbia type wheel arrangement, and was built especially for mainline passenger express services. |
https://en.wikipedia.org/wiki/Pressure-gradient%20force | In fluid mechanics, the pressure-gradient force is the force that results when there is a difference in pressure across a surface. In general, a pressure is a force per unit area across a surface. A difference in pressure across a surface then implies a difference in force, which can result in an acceleration according to Newton's second law of motion, if there is no additional force to balance it. The resulting force is always directed from the region of higher-pressure to the region of lower-pressure. When a fluid is in an equilibrium state (i.e. there are no net forces, and no acceleration), the system is referred to as being in hydrostatic equilibrium. In the case of atmospheres, the pressure-gradient force is balanced by the gravitational force, maintaining hydrostatic equilibrium. In Earth's atmosphere, for example, air pressure decreases at altitudes above Earth's surface, thus providing a pressure-gradient force which counteracts the force of gravity on the atmosphere.
Magnus effect
The Magnus effect is an observable phenomenon that is commonly associated with a spinning object moving through a fluid. The path of the spinning object is deflected in a manner that is not present when the object is not spinning. The deflection can be explained by the difference in pressure of the fluid on opposite sides of the spinning object. The Magnus effect is dependent on the speed of rotation.
Formalism
Consider a cubic parcel of fluid with a density , a height , and a sur |
https://en.wikipedia.org/wiki/Semidefinite%20embedding | Maximum Variance Unfolding (MVU), also known as Semidefinite Embedding (SDE), is an algorithm in computer science that uses semidefinite programming to perform non-linear dimensionality reduction of high-dimensional vectorial input data.
It is motivated by the observation that kernel Principal Component Analysis (kPCA) does not reduce the data dimensionality, as it leverages the Kernel trick to non-linearly map the original data into an inner-product space.
Algorithm
MVU creates a mapping from the high dimensional input vectors to some low dimensional Euclidean vector space in the following steps:
A neighbourhood graph is created. Each input is connected with its k-nearest input vectors (according to Euclidean distance metric) and all k-nearest neighbors are connected with each other. If the data is sampled well enough, the resulting graph is a discrete approximation of the underlying manifold.
The neighbourhood graph is "unfolded" with the help of semidefinite programming. Instead of learning the output vectors directly, the semidefinite programming aims to find an inner product matrix that maximizes the pairwise distances between any two inputs that are not connected in the neighbourhood graph while preserving the nearest neighbors distances.
The low-dimensional embedding is finally obtained by application of multidimensional scaling on the learned inner product matrix.
The steps of applying semidefinite programming followed by a linear dimensionality reduction st |
https://en.wikipedia.org/wiki/Conductive%20hearing%20loss | Conductive hearing loss (CHL) occurs when there is a problem transferring sound waves anywhere along the pathway through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles). If a conductive hearing loss occurs in conjunction with a sensorineural hearing loss, it is referred to as a mixed hearing loss. Depending upon the severity and nature of the conductive loss, this type of hearing impairment can often be treated with surgical intervention or pharmaceuticals to partially or, in some cases, fully restore hearing acuity to within normal range. However, cases of permanent or chronic conductive hearing loss may require other treatment modalities such as hearing aid devices to improve detection of sound and speech perception.
Causes
Common causes of conductive hearing loss include:
External ear
Cerumen (earwax) or foreign body in the external auditory canal
Otitis externa, infection or irritation of the outer ear
Exostoses, abnormal growth of bone within the ear canal
Tumor of the ear canal
Congenital stenosis or atresia of the external auditory canal (narrow or blocked ear canal).
Ear canal stenosis & atresia can exist independently or may result from congenital malformations of the auricle such as microtia or anotia.
Acquired stenosis (narrowing) of the external auditory canal following surgery or radiotherapy
Middle ear
Fluid accumulation is the most common cause of conductive hearing loss in the middle ear, especially in children. Major causes a |
https://en.wikipedia.org/wiki/Dermochelyidae | Dermochelyidae is a family of turtles which has seven extinct genera and one extant genus, including the largest living sea turtles.
Classification of known genera
The following list of dermochelyid species was published by Hirayama and Tong in 2003, unless otherwise noted.
Arabemys crassiscutata
†Eosphargis breineri
Mesodermochelys undulatus
Subfamily Dermochelyinae
†Cosmochelys
Dermochelys coriacea – leatherback sea turtle
†Psephophorus
Phylogeny
Evers et al. (2019):
References
Bibliography
External links
Family Dermochelyidae (Leatherback turtles) from Turtles of the World by C.H. Ernst, R.G.M. Altenburg & R.W. Barbour
Taxa named by Leopold Fitzinger
Turtle families
Santonian first appearances
Extant Santonian first appearances |
https://en.wikipedia.org/wiki/Polyvinyl%20fluoride | Polyvinyl fluoride (PVF) or –(CH2CHF)n– is a polymer material mainly used in the flammability-lowering coatings of airplane interiors and photovoltaic module backsheets. It is also used in raincoats and metal sheeting. Polyvinyl fluoride is a thermoplastic fluoropolymer with a repeating vinyl fluoride unit, and it is structurally very similar to polyvinyl chloride.
PVF has low permeability for vapors, burns very slowly, and has excellent resistance to weathering and staining. It is also resistant to most chemicals, except ketones and esters. It is available as a film in a variety of colors and formulations for various end uses, and as a resin for specialty coatings. It has insufficient thermal stability for injection moulding and thus it is usually available commercially as a film product.
PVF is also used as whiteboard surface material and has recently been used as part of the Phoenix Mars Lander's biobarrier.
Related compounds
Vinyl fluoride
PVC (polyvinyl chloride)
PVDF (polyvinylidene fluoride)
PTFE (polytetrafluoroethylene or Teflon)
References
External links
polyvinyl fluoride (PVF)
Fluoropolymers
Plastics
Thermoplastics
Airship technology
Vinyl polymers |
https://en.wikipedia.org/wiki/Eqn%20%28software%29 | Part of the troff suite of Unix document layout tools, eqn is a preprocessor that formats equations for printing. A similar program, neqn, accepted the same input as eqn, but produced output tuned to look better in nroff. The eqn program was created in 1974 by Brian Kernighan and Lorinda Cherry.
It was implemented using yacc compiler-compiler.
The input language used by eqn allows the user to write mathematical expressions in much the same way as they would be spoken aloud. The language is defined by a context-free grammar, together with operator precedence and operator associativity rules. The eqn language is similar to the mathematical component of TeX, which appeared several years later, but is simpler and less complete.
An independent compatible implementation of the eqn preprocessor has been developed by GNU as part of groff, the GNU version of troff. The GNU implementation extends the original language by adding a number of new keywords such as smallover and accent. mandoc, a specialised compiler for UNIX man pages, also contains a standalone eqn parser/formatter.
History
Eqn was done by using yacc parser generator.
Syntax examples
Here is how some examples would be written in eqn (with equivalents in TeX for comparison):
Spaces are important in eqn; tokens are delimited only by whitespace characters, tildes ~, braces {} and double-quotes "". Thus f(pi r sup 2) results in , whereas f( pi r sup 2 ) is needed to give the intended .
References
Bibliography
Ex |
https://en.wikipedia.org/wiki/Diaphragm%20%28acoustics%29 | In the field of acoustics, a diaphragm is a transducer intended to inter-convert mechanical vibrations to sounds, or vice versa. It is commonly constructed of a thin membrane or sheet of various materials, suspended at its edges. The varying air pressure of sound waves imparts mechanical vibrations to the diaphragm which can then be converted to some other type of signal; examples of this type of diaphragm are found in microphones and the human eardrum. Conversely a diaphragm vibrated by a source of energy beats against the air, creating sound waves. Examples of this type of diaphragm are loudspeaker cones and earphone diaphragms and are found in air horns.
Loudspeaker
In a dynamic loudspeaker, a diaphragm is the thin, semi-rigid membrane attached to the voice coil, which moves in a magnetic gap, vibrating the diaphragm, and producing sound. It can also be called a cone, though not all speaker diaphragms are cone-shaped. Diaphragms are also found in headphones.
Quality midrange and bass drivers are usually made from paper, paper composites and laminates, plastic materials such as polypropylene, or mineral/fiber-filled polypropylene. Such materials have very high strength/weight ratios (paper being even higher than metals) and tend to be relatively immune from flexing during large excursions. This allows the driver to react quickly during transitions in music (i.e. fast changing transient impulses) and minimizes acoustical output distortion.
If properly designed in |
https://en.wikipedia.org/wiki/Pseudo-Hadamard%20transform | The pseudo-Hadamard transform is a reversible transformation of a bit string that provides cryptographic diffusion. See Hadamard transform.
The bit string must be of even length so that it can be split into two bit strings a and b of equal lengths, each of n bits. To compute the transform for Twofish algorithm, a' and b', from these we use the equations:
To reverse this, clearly:
On the other hand, the transformation for SAFER+ encryption is as follows:
Generalization
The above equations can be expressed in matrix algebra, by considering a and b as two elements of a vector, and the transform itself as multiplication by a matrix of the form:
The inverse can then be derived by inverting the matrix.
However, the matrix can be generalised to higher dimensions, allowing vectors of any power-of-two size to be transformed, using the following recursive rule:
For example:
See also
SAFER
Twofish
This is the Kronecker product of an Arnold Cat Map matrix with a Hadamard matrix.
References
James Massey, "On the Optimality of SAFER+ Diffusion", 2nd AES Conference, 1999.
Bruce Schneier, John Kelsey, Doug Whiting, David Wagner, Chris Hall, "Twofish: A 128-Bit Block Cipher", 1998.
Helger Lipmaa. On Differential Properties of Pseudo-Hadamard Transform and Related Mappings. INDOCRYPT 2002, LNCS 2551, pp 48-61, 2002.
External links
Fast Pseudo-Hadamard Transforms
Theory of cryptography
Transforms |
https://en.wikipedia.org/wiki/Block%20design | In combinatorial mathematics, a block design is an incidence structure consisting of a set together with a family of subsets known as blocks, chosen such that frequency of the elements satisfies certain conditions making the collection of blocks exhibit symmetry (balance). Block designs have applications in many areas, including experimental design, finite geometry, physical chemistry, software testing, cryptography, and algebraic geometry.
Without further specifications the term block design usually refers to a balanced incomplete block design (BIBD), specifically (and also synonymously) a 2-design, which has been the most intensely studied type historically due to its application in the design of experiments. Its generalization is known as a t-design.
Overview
A design is said to be balanced (up to t) if all t-subsets of the original set occur in equally many (i.e., λ) blocks. When t is unspecified, it can usually be assumed to be 2, which means that each pair of elements is found in the same number of blocks and the design is pairwise balanced. For t=1, each element occurs in the same number of blocks (the replication number, denoted r) and the design is said to be regular. Any design balanced up to t is also balanced in all lower values of t (though with different λ-values), so for example a pairwise balanced (t=2) design is also regular (t=1). When the balancing requirement fails, a design may still be partially balanced if the t-subsets can be divided into n classes, |
https://en.wikipedia.org/wiki/ICE%20%28cipher%29 | In cryptography, ICE (Information Concealment Engine) is a symmetric-key block cipher published by Kwan in 1997. The algorithm is similar in structure to DES, but with the addition of a key-dependent bit permutation in the round function. The key-dependent bit permutation is implemented efficiently in software. The ICE algorithm is not subject to patents, and the source code has been placed into the public domain.
ICE is a Feistel network with a block size of 64 bits. The standard ICE algorithm takes a 64-bit key and has 16 rounds. A fast variant, Thin-ICE, uses only 8 rounds. An open-ended variant, ICE-n, uses 16n rounds with 64n bit key.
Van Rompay et al. (1998) attempted to apply differential cryptanalysis to ICE. They described an attack on Thin-ICE which recovers the secret key using 223 chosen plaintexts with a 25% success probability. If 227 chosen plaintexts are used, the probability can be improved to 95%. For the standard version of ICE, an attack on 15 out of 16 rounds was found, requiring 256 work and at most 256 chosen plaintexts.
Structure
ICE is a 16-round Feistel network. Each round uses a 32→32 bit F function, which uses 60 bits of key material.
The structure of the F function is somewhat similar to DES: The input is expanded by taking overlapping fields, the expanded input is XORed with a key, and the result is fed to a number of reducing S-boxes which undo the expansion.
First, ICE divides the input into 4 overlapping 10-bit values. They are bits 3 |
https://en.wikipedia.org/wiki/Relaxed%20code-excited%20linear%20prediction | Relaxed code-excited linear prediction (RCELP) is a method used in some advanced speech codecs. The RCELP algorithm does not attempt to match the original signal exactly. Instead, it matches a time-warped version of this original signal that conforms to a simplified pitch contour.
References
Speech codecs |
https://en.wikipedia.org/wiki/Low-frequency%20oscillation | Low-frequency oscillation (LFO) is an electronic frequency that is usually below 20 Hz and creates a rhythmic pulse or sweep. This is used to modulate musical equipment such as synthesizers to create audio effects such as vibrato, tremolo and phasing.
History
Low-frequency oscillation was introduced with modular synthesizers of the 1960s, such as the Moog synthesizer. Often the LFO effect was accidental, as there were myriad configurations that could be "patched" by the synth operator. LFOs have since appeared in some form on almost every synthesizer. More recently other electronic musical instruments, such as samplers and software synthesizers, have included LFOs to increase their sound alteration capabilities.
Overview
The primary oscillator circuits of a synthesizer are used to create the audio signals. An LFO is a secondary oscillator that operates at a significantly lower frequency than other oscillators, typically below 20 Hz — that is, below the range of human hearing. The frequencies generated by LFOs are used as control signals which modulate another component's value, changing the output sound without introducing another source. Like a standard oscillator, this usually takes the form of a periodic waveform, such as a sine, sawtooth, triangle or square wave. Also like a standard oscillator, LFOs can incorporate any number of waveform types, including user-defined wavetables, rectified waves and random signals.
Using a low-frequency oscillation signal as a means of |
https://en.wikipedia.org/wiki/Enterovirus | Enterovirus is a genus of positive-sense single-stranded RNA viruses associated with several human and mammalian diseases. Enteroviruses are named by their transmission-route through the intestine ('enteric' meaning intestinal).
Serologic studies have distinguished 71 human enterovirus serotypes on the basis of antibody neutralization tests. Additional antigenic variants have been defined within several of the serotypes on the basis of reduced or nonreciprocal cross-neutralization between variant strains. On the basis of their pathogenesis in humans and animals, the enteroviruses were originally classified into four groups, polioviruses, Coxsackie A viruses (CA), Coxsackie B viruses (CB), and echoviruses, but it was quickly realized that there were significant overlaps in the biological properties of viruses in the different groups. Enteroviruses isolated more recently are named with a system of consecutive numbers: EV-D68, EV-B69, EV-D70, EV-A71, etc., where genotyping is based on the VP1 capsid region.
Enteroviruses affect millions of people worldwide each year and are often found in the respiratory secretions (e.g., saliva, sputum, or nasal mucus) and stool of an infected person. Historically, poliomyelitis was the most significant disease caused by an enterovirus, namely poliovirus. There are 81 non-polio and 3 polio enteroviruses that can cause disease in humans. Of the 81 non-polio types, there are 22 Coxsackie A viruses, 6 Coxsackie B viruses, 28 echoviruses, and 25 |
https://en.wikipedia.org/wiki/Abraham%E2%80%93Minkowski%20controversy | The Abraham–Minkowski controversy is a physics debate concerning electromagnetic momentum within dielectric media. Two equations were first suggested by Hermann Minkowski (1908) and Max Abraham (1909) for this momentum. They predict different values, from which the name of the controversy derives. Experimental support has been claimed for both.
The two points of view have different physical interpretations and thus neither need be more correct than the other.
David J. Griffiths argues that, in the presence of matter, only the total stress–energy tensor carries unambiguous physical significance; how one apportions it between an "electromagnetic" part and a "matter" part depends on context and convenience.
Several papers have claimed to have resolved this controversy.
The controversy is still of importance in physics beyond the Standard Model where electrodynamics gets modifications, like in the presence of axions.
References
External links
Physical Review Focus: Momentum From Nothing
Physical Review Focus: Light Bends Glass
Electric and magnetic fields in matter
Hermann Minkowski
1908 introductions |
https://en.wikipedia.org/wiki/Graviphoton | In theoretical physics and quantum physics, a graviphoton or gravivector is a hypothetical particle which emerges as an excitation of the metric tensor (i.e. gravitational field) in spacetime dimensions higher than four, as described in Kaluza–Klein theory.
However, its crucial physical properties are analogous to a (massive) photon: it induces a "vector force", sometimes dubbed a "fifth force". The electromagnetic potential emerges from an extra component of the metric tensor , where the figure 5 labels an additional, fifth dimension.
In gravity theories with extended supersymmetry (extended supergravities), a graviphoton is normally a superpartner of the graviton that behaves like a photon, and is prone to couple with gravitational strength, as was appreciated in the late 1970s. Unlike the graviton, it may provide a repulsive (as well as an attractive) force, and thus, in some technical sense, a type of anti-gravity. Under special circumstances, in several natural models, often descending from five-dimensional theories mentioned, it may actually cancel the gravitational attraction in the static limit. Joël Scherk investigated semirealistic aspects of this phenomenon, stimulating searches for physical manifestations of this mechanism.
See also
Graviscalar (a.k.a. radion)
Supergravity
References
Supersymmetry
Bosons
Photons
Hypothetical elementary particles
Force carriers
Subatomic particles with spin 1 |
https://en.wikipedia.org/wiki/Graviscalar | In theoretical physics, the hypothetical particle called the graviscalar or radion emerges as an excitation of general relativity's metric tensor, i.e. gravitational field, but is indistinguishable from a scalar in four dimensions, as shown in Kaluza–Klein theory. The scalar field comes from a component of the metric tensor where the figure 5 labels an additional fifth dimension. The only variations in the scalar field represent variations in the size of the extra dimension. Also, in models with multiple extra dimensions, there exist several such particles. Moreover, in theories with extended supersymmetry, a graviscalar is usually a superpartner of the graviton that behaves as a particle with spin 0. This concept closely relates to the gauged Higgs models.
See also
Graviphoton (aka gravivector)
Dilaton
Kaluza–Klein theory
Randall–Sundrum models
Goldberger–Wise mechanism
References
Roy Maartens, “Brane-World Gravity”, Living Rev. Relativ., 7, (2004), 7. ,
Supersymmetry
Theories of gravity
Hypothetical elementary particles
Force carriers |
https://en.wikipedia.org/wiki/Ice%20Ih | {{DISPLAYTITLE:Ice Ih}}
Ice Ih (hexagonal ice crystal) (pronounced: ice one h, also known as ice-phase-one) is the hexagonal crystal form of ordinary ice, or frozen water. Virtually all ice in the biosphere is ice Ih, with the exception only of a small amount of ice Ic that is occasionally present in the upper atmosphere. Ice Ih exhibits many peculiar properties that are relevant to the existence of life and regulation of global climate. For a description of these properties, see Ice, which deals primarily with ice Ih.
The crystal structure is characterized by the oxygen atoms forming hexagonal symmetry with near tetrahedral bonding angles. Ice Ih is stable down to , as evidenced by x-ray diffraction and extremely high resolution thermal expansion measurements. Ice Ih is also stable under applied pressures of up to about where it transitions into ice III or ice II.
Physical properties
The density of ice Ih is 0.917 g/cm3 which is less than that of liquid water. This is attributed to the presence of hydrogen bonds which causes atoms to become closer in the liquid phase. Because of this, ice Ih floats on water, which is highly unusual when compared to other materials. The solid phase of materials is usually more closely and neatly packed and has a higher density than the liquid phase. When lakes freeze, they do so only at the surface while the bottom of the lake remains near because water is densest at this temperature. No matter how cold the surface becomes, there is alwa |
https://en.wikipedia.org/wiki/Electric%20displacement%20field | In physics, the electric displacement field (denoted by D) or electric induction is a vector field that appears in Maxwell's equations. It accounts for the electromagnetic effects of polarization and that of an electric field, combining the two in an auxiliary field. It plays a major role in topics such as the capacitance of a material, as well the response of dielectrics to electric field, and how shapes can change due to electric fields in piezoelectricity or flexoelectricity as well as the creation of voltages and charge transfer due to elastic strains.
In any material, if there is an inversion center then the charge at, for instance, and are the same. This means that there is no dipole. If an electric field is applied to an insulator, then (for instance) the negative charges can move slightly towards the positive side of the field, and the positive charges in the other direction. This leads to an induced dipole which is described as a polarization. There can be slightly different movements of the negative electrons and positive nuclei in molecules, or different displacements of the atoms in an ionic compound. Materials which do not have an inversion center display piezoelectricity and always have a polarization; in others spatially varying strains can break the inversion symmetry and lead to polarization, the flexoelectric effect. Other stimuli such as magnetic fields can lead to polarization in some materials, this being called the magnetoelectric effect.
Definition |
https://en.wikipedia.org/wiki/No-trade%20theorem | In financial economics, the no-trade theorem states that if
markets are in a state of efficient equilibrium
there are no noise traders or other non-rational interferences with prices
the structure by which traders or potential traders acquire information is itself common knowledge
then even though some traders may possess private information, none of them will be in a position to profit from it. The assumptions are deliberately unrealistic, but the theorem may nonetheless be pertinent to debates over inside information.
It was demonstrated by Paul Milgrom and Nancy Stokey in their 1982 paper, "Information, trade and common knowledge".
Informal explanation
The idea behind the proof of the no-trade theorem is that if there is common knowledge about the structure of a market, then any bid or offer (i.e. attempt to initiate a trade) will reveal the bidder's private knowledge and will be incorporated into market prices even before anyone accepts the bid or offer, so no profit will result. Another way to put it is: all the traders in the market are rational, and thus they know that all the prices are rational/efficient; therefore, anyone who makes an offer to them must have special knowledge, else why would they be making the offer? Accepting the offer would make them a loser. All the traders will reason the same way, and thus will not accept any offers.
Notes
See also
Myerson–Satterthwaite theorem - a different theorem that predicts no trade in a strategic context.
Ec |
https://en.wikipedia.org/wiki/RC%20oscillator | Linear electronic oscillator circuits, which generate a sinusoidal output signal, are composed of an amplifier and a frequency selective element, a filter. A linear oscillator circuit which uses an RC network, a combination of resistors and capacitors, for its frequency selective part is called an RC oscillator.
Description
RC oscillators are a type of feedback oscillator; they consist of an amplifying device, a transistor, vacuum tube, or op-amp, with some of its output energy fed back into its input through a network of resistors and capacitors, an RC network, to achieve positive feedback, causing it to generate an oscillating sinusoidal voltage. They are used to produce lower frequencies, mostly audio frequencies, in such applications as audio signal generators and electronic musical instruments. At radio frequencies, another type of feedback oscillator, the LC oscillator is used, but at frequencies below 100 kHz the size of the inductors and capacitors needed for the LC oscillator become cumbersome, and RC oscillators are used instead. Their lack of bulky inductors also makes them easier to integrate into microelectronic devices. Since the oscillator's frequency is determined by the value of resistors and capacitors, which vary with temperature, RC oscillators do not have as good frequency stability as crystal oscillators.
The frequency of oscillation is determined by the Barkhausen criterion, which says that the circuit will only oscillate at frequencies for whic |
https://en.wikipedia.org/wiki/Skellam%20distribution | The Skellam distribution is the discrete probability distribution of the difference of two statistically independent random variables and each Poisson-distributed with respective expected values and . It is useful in describing the statistics of the difference of two images with simple photon noise, as well as describing the point spread distribution in sports where all scored points are equal, such as baseball, hockey and soccer.
The distribution is also applicable to a special case of the difference of dependent Poisson random variables, but just the obvious case where the two variables have a common additive random contribution which is cancelled by the differencing: see Karlis & Ntzoufras (2003) for details and an application.
The probability mass function for the Skellam distribution for a difference between two independent Poisson-distributed random variables with means and is given by:
where Ik(z) is the modified Bessel function of the first kind. Since k is an integer we have that Ik(z)=I|k|(z).
Derivation
The probability mass function of a Poisson-distributed random variable with mean μ is given by
for (and zero otherwise). The Skellam probability mass function for the difference of two independent counts is the convolution of two Poisson distributions: (Skellam, 1946)
Since the Poisson distribution is zero for negative values of the count , the second sum is only taken for those terms where and . It can be shown that the above sum implies that
so |
https://en.wikipedia.org/wiki/Nottingham%20Urban%20Area | The Nottingham Built-up Area (BUA), Nottingham Urban Area, or Greater Nottingham is an area of land defined by the Office for National Statistics as which is built upon, with nearby areas linked if within 200 metres. It consists of the city of Nottingham and the adjoining urban areas of Nottinghamshire and Derbyshire, in the East Midlands of England. It had a total population of 729,977 at the time of the 2011 census. This was an increase of almost 10% since the 2001 census recorded population of 666,358, due to population increases, reductions and several new sub-divisions.
Geography
Greater Nottingham is largely within the three districts of Rushcliffe, Broxtowe and Gedling surrounding the city, though the area spills into the Nottinghamshire district of Ashfield, and also to the Amber Valley and Erewash districts of Derbyshire. The Nottingham Urban Area is, by the ONS' figures, the 8th largest in England (9th in the UK), with a population size between that of the Tyneside and Sheffield built-up areas, and a total area of .
The Nottingham Urban Area is bounded to the west by a narrow gap between Draycott (to the west of the Breaston urban area sub-division) and Borrowash (to the east of the Derby Urban Area). The Heanor/Ripley and West Hallam north-western extensions have a somewhat tenuous linkage through to the core of Nottingham City largely due to ribbon development, and are in close proximity to other nearby urban areas which together, almost link to Derby from the |
https://en.wikipedia.org/wiki/Poisson%20formula | In mathematics, the Poisson formula, named after Siméon Denis Poisson, may refer to:
Poisson distribution in probability
Poisson summation formula in Fourier analysis
Poisson kernel in complex or harmonic analysis
Poisson–Jensen formula in complex analysis |
https://en.wikipedia.org/wiki/Picrotoxin | Picrotoxin, also known as cocculin, is a poisonous crystalline plant compound. It was first isolated by the French pharmacist and chemist Pierre François Guillaume Boullay (1777–1869) in 1812. The name "picrotoxin" is a combination of the Greek words "picros" (bitter) and "toxicon" (poison). A mixture of two different compounds, picrotoxin occurs naturally in the fruit of the Anamirta cocculus plant, although it can also be synthesized chemically.
Due to its interactions with the inhibitory neurotransmitter GABA, picrotoxin acts as a stimulant and convulsant. It mainly impacts the central nervous system, causing seizures and respiratory paralysis in high enough doses.
Chemical structure and synthesis
Picrotoxin is an equimolar mixture of two compounds, picrotoxinin (C15H16O6; CAS# 17617-45-7) and picrotin (C15H18O7; CAS# 21416-53-5). Of the two compounds, picrotin is less active.
Picrotoxin occurs naturally in the fruit of the Anamirta cocculus, a climbing plant from India and other parts of Southeast Asia. The plant is known for its large stems of white wood and sweetly-scented flowers. It produces small stone fruits, Cocculus indicus, which are typically dried.
Currently, there are as many as five total syntheses of picrotoxinin — one of which was published as recently as June 2020. Most syntheses use carvone as a stereochemical template.
In 1988, researchers from Tohoku University in Japan completed a total stereoselective synthesis of both ()picrotoxinin and beg |
https://en.wikipedia.org/wiki/Heine%E2%80%93Cantor%20theorem | In mathematics, the Heine–Cantor theorem, named after Eduard Heine and Georg Cantor, states that if is a continuous function between two metric spaces and , and is compact, then is uniformly continuous. An important special case is that every continuous function from a closed bounded interval to the real numbers is uniformly continuous.
Proof
Suppose that and are two metric spaces with metrics and , respectively. Suppose further that a function is continuous and is compact. We want to show that is uniformly continuous, that is, for every positive real number there exists a positive real number such that for all points in the function domain , implies that .
Consider some positive real number . By continuity, for any point in the domain , there exists some positive real number such that when , i.e., a fact that is within of implies that is within of .
Let be the open -neighborhood of , i.e. the set
Since each point is contained in its own , we find that the collection is an open cover of . Since is compact, this cover has a finite subcover where . Each of these open sets has an associated radius . Let us now define , i.e. the minimum radius of these open sets. Since we have a finite number of positive radii, this minimum is well-defined and positive. We now show that this works for the definition of uniform continuity.
Suppose that for any two in . Since the sets form an open (sub)cover of our space , we know that must lie within one of |
https://en.wikipedia.org/wiki/Flexible%20organic%20light-emitting%20diode | A flexible organic light-emitting diode (FOLED) is a type of organic light-emitting diode (OLED) incorporating a flexible plastic substrate on which the electroluminescent organic semiconductor is deposited. This enables the device to be bent or rolled while still operating. Currently the focus of research in industrial and academic groups, flexible OLEDs form one method of fabricating a rollable display.
Technical details and applications
An OLED emits light due to the electroluminescence of thin films of organic semiconductors approximately 100 nm thick. Regular OLEDs are usually fabricated on a glass substrate, but by replacing glass with a flexible plastic such as polyethylene terephthalate (PET) among others, OLEDs can be made both bendable and lightweight.
Such materials may not be suitable for comparable devices based on inorganic semiconductors due to the need for lattice matching and the high temperature fabrication procedure involved.
In contrast, flexible OLED devices can be fabricated by deposition of the organic layer onto the substrate using a method derived from inkjet printing, allowing the inexpensive and roll-to-roll fabrication of printed electronics.
Flexible OLEDs may be used in the production of rollable displays, electronic paper, or bendable displays which can be integrated into clothing, wallpaper or other curved surfaces. Prototype displays have been exhibited by companies such as Sony, which are capable of being rolled around the width of a pe |
https://en.wikipedia.org/wiki/ASR | ASR may refer to:
Military
Hull classification symbol for submarine rescue ship in some navies
U.S. Army Service Ribbon
Organizations and publications
ASR Nederland, a Dutch insurance company
Academy at Swift River
Erkilet International Airport, Turkey, IATA code
Science
Ancestral sequence reconstruction, to infer ancient DNA sequences
Acute stress reaction to traumatic event
Adult sex ratio of males to females
Alkali–silica reaction, affecting sensitive aggregates and causing concrete expansion and failure
Analyte-specific reagent, a class of biological molecules
Asian soybean rust, a plant disease
Age-Standardized Rates of a phenomenon in a series of populations.
Technology
Automatic speech recognition
Automotive shredder residue, of shredded automobiles
Aquifer storage and recovery, of potable water in an aquifer
Airport surveillance radar
Asr (radar), an Iranian radar system
Arithmetic shift right, a computer instruction
Answer-seizure ratio, the percentage of telephone calls that are answered
Traction control system, from German Antriebsschlupfregelung (Acceleration Slip Regulation), system to prevent loss of traction on vehicles
Automatic Send Receive on a teletype
Teletype ASR 33, a specific model teletype, commonly used for early day minicomputers
Architecturally Significant Requirements
Software
Apple Software Restore, a command line utility in Mac OS X
Automated system recovery, a Microsoft Windows XP function
Transport
Air-sea resc |
https://en.wikipedia.org/wiki/Hilbert%E2%80%93Schmidt | In mathematics, Hilbert–Schmidt may refer to
a Hilbert–Schmidt operator;
a Hilbert–Schmidt integral operator;
the Hilbert–Schmidt theorem. |
https://en.wikipedia.org/wiki/Frazil%20ice | Frazil ice is a collection of loose, randomly oriented ice crystals millimeter and sub-millimeter in size, with various shapes, e.g. elliptical disks, dendrites, needles and of an irregular nature. Frazil ice forms during the winter in open-water reaches of rivers as well as in lakes and reservoirs, where and when the water is in a turbulent state, which is, in turn, induced by the action of waves and currents. Turbulence causes the water column to become supercooled, as the heat exchange between the air and the water is such that the water temperature drops below its freezing point (in order of a few tenths of °C or less). The vertical mixing associated with that turbulence provides enough energy to overcome the crystals' buoyancy, thus keeping them from floating at the surface. Frazil ice also forms in oceans, where windy conditions, wave regimes and cold air also favor the establishment of a supercooled layer. Frazil ice can be found on the downwind side of leads, and in polynyas. In these environments, that ice can eventually accumulate at the water surface into what is referred to as grease ice.
Frazil ice is notorious for blocking water intakes as crystals accumulate and build up on the intake trash rack. Such blockages negatively impact water supply facilities, hydropower plants, nuclear power facilities, and vessels navigating in cold waters, and can lead to unexpected shut downs of the facility or even collapse of the trash rack.
Formation
When the water surfac |
https://en.wikipedia.org/wiki/Biodiversity%20of%20New%20Caledonia | The biodiversity of New Caledonia is of exceptional biological and paleoecological interest. It is frequently referred to as a biodiversity hotspot. The country is a large South Pacific archipelago with a total land area of more than . The terrain includes a variety of reefs, atolls, small islands, and a variety of topographical and edaphic regions on the largest island, all of which promote the development of unusually concentrated biodiversity. The region's climate is oceanic and tropical.
New Caledonia is separated from the nearest mainland by more than of open sea. Its isolation dates from at least the mid-Miocene, and possibly from the Oligocene, and that isolation has preserved its relict biota, fostering the evolution of wide ranges of endemic species.
Location and description
New Caledonia lies on the southernmost edge of the tropical zone, near the Tropic of Capricorn. It is part of the Melanesia subregion. It includes the main island of Grande Terre, the Loyalty Islands, the Belep archipelago, the Isle of Pines, the Chesterfield Islands in the Coral Sea, and a few remote islets.
The archipelago is about east of Australia and 1500 km, 1800 km and 1200 km from New Zealand, Papua New Guinea and Fiji respectively. A few lesser islands are closer, but now provide no convenient island-hopping path by which animal species could pass either to or from major mainlands. Some plants, invertebrates, sea mammals, and many flying species as aquatic birds, parrots, and bats h |
https://en.wikipedia.org/wiki/Side-chain | Side-chain, side chain, or sidechain may refer to:
Side chain, a chemical group attached to the main chain or backbone of a molecule, such as a protein
Substituent, an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon
Side-chaining, an effect in digital audio processing
Sidechain (ledger), a designation for a particular blockchain
"Sidechain", a song by Knuckle Puck from the album 20/20
See also
Backbone chain
Branching (polymer chemistry)
Pendant group |
https://en.wikipedia.org/wiki/Mohr%E2%80%93Mascheroni%20theorem | In mathematics, the Mohr–Mascheroni theorem states that any geometric construction that can be performed by a compass and straightedge can be performed by a compass alone.
It must be understood that "any geometric construction" refers to figures that contain no straight lines, as it is clearly impossible to draw a straight line without a straightedge. It is understood that a line is determined provided that two distinct points on that line are given or constructed, even though no visual representation of the line will be present. The theorem can be stated more precisely as:
Any Euclidean construction, insofar as the given and required elements are points (or circles), may be completed with the compass alone if it can be completed with both the compass and the straightedge together.
Though the use of a straightedge can make a construction significantly easier, the theorem shows that any set of points that fully defines a constructed figure can be determined with compass alone, and the only reason to use a straightedge is for the aesthetics of seeing straight lines, which for the purposes of construction is functionally unnecessary.
History
The result was originally published by Georg Mohr in 1672, but his proof languished in obscurity until 1928. The theorem was independently discovered by Lorenzo Mascheroni in 1797 and it was known as Mascheroni's Theorem until Mohr's work was rediscovered.
Several proofs of the result are known. Mascheroni's proof of 1797 was generall |
https://en.wikipedia.org/wiki/Laws%20of%20robotics | Laws of robotics are any set of laws, rules, or principles, which are intended as a fundamental framework to underpin the behavior of robots designed to have a degree of autonomy. Robots of this degree of complexity do not yet exist, but they have been widely anticipated in science fiction, films and are a topic of active research and development in the fields of robotics and artificial intelligence.
The best known set of laws are those written by Isaac Asimov in the 1940s, or based upon them, but other sets of laws have been proposed by researchers in the decades since then.
Isaac Asimov's "Three Laws of Robotics"
The best known set of laws are Isaac Asimov's "Three Laws of Robotics". These were introduced in his 1942 short story "Runaround", although they were foreshadowed in a few earlier stories. The Three Laws are:
A robot may not injure a human being or, through inaction, allow a human being to come to harm.
A robot must obey the orders by human beings except where such orders would conflict with the First Law.
A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.
In The Evitable Conflict the machines generalize the First Law to mean:
No machine may harm humanity; or, through inaction, allow humanity to come to harm.
This was refined in the end of Foundation and Earth, a zeroth law was introduced, with the original three suitably rewritten as subordinate to it:
Adaptations and extensions exist ba |
https://en.wikipedia.org/wiki/RiboGreen | RiboGreen is a proprietary fluorescent dye that is used in the detection and quantification of nucleic acids, including both RNA and DNA. It is synthesized and marketed by Molecular Probes/Invitrogen (a division of Life Technologies, now part of Thermo Fisher Scientific) of Eugene, Oregon, United States. In its free form, RiboGreen exhibits little fluorescence and possesses a negligible absorbance signature. When bound to nucleic acids, the dye fluoresces with an intensity that, according to the manufacturer, is several orders of magnitude greater than the unbound form. The fluorescence can be detected by a sensor and the nucleic acid can be quantified. The presence of protein contaminants in the sample of nucleic acids to be tested does not make significant contributions to the absorbance, and thus allows for the addition of deoxyribonucleases to the protocol in order to degrade DNA, in the instances where one is only interested in detecting or quantifying RNA.
References
External links
Quant-iT™ RiboGreen® RNA Reagent
Thermo Fisher Scientific RiboGreen Manual
Staining dyes
Fluorescent dyes |
https://en.wikipedia.org/wiki/Reed%20valve | Reed valves are a type of check valve which restrict the flow of fluids to a single direction, opening and closing under changing pressure on each face. Modern versions often consist of flexible metal or composite materials (fiberglass or carbon fiber).
Applications
Traditional
Reed valves, normally a leather flap covering a hole, are amongst the earliest form of automatic flow control for liquids and gases. They have been used for thousands of years in water pumps and for hundreds of years in bellows for high-temperature forges and musical instruments such as church organs and accordions. In nature, heart valves operate in a somewhat similar fashion.
Pumps
Reed valves are used in some reciprocating compressor designs, and in the pumping element of some musical instruments, large and small.
Two-stroke engines
Reed valves are commonly used in high-performance versions of the two-stroke engine, where they control the fuel-air mixture admitted to the cylinder. As the piston rises in the cylinder a vacuum is created in the crankcase beneath the piston. The resulting pressure differential opens the valve and the fuel-air mixture flows into the crankcase. As the piston descends, it raises the crankcase pressure causing the valve to close to retain the mixture and pressurize it for its eventual transfer through to the combustion chamber. The Swedish motorcycle company Husqvarna produced a two-stroke, 500 cc displacement single cylinder engine with a reed-valve controlled inta |
https://en.wikipedia.org/wiki/Direct%20digital%20synthesis | Direct digital synthesis (DDS) is a method employed by frequency synthesizers used for creating arbitrary waveforms from a single, fixed-frequency reference clock. DDS is used in applications such as signal generation, local oscillators in communication systems, function generators, mixers, modulators, sound synthesizers and as part of a digital phase-locked loop.
Overview
A basic Direct Digital Synthesizer consists of a frequency reference (often a crystal or SAW oscillator), a numerically controlled oscillator (NCO) and a digital-to-analog converter (DAC) as shown in Figure 1.
The reference oscillator provides a stable time base for the system and determines the frequency accuracy of the DDS. It provides the clock to the NCO, which produces at its output a discrete-time, quantized version of the desired output waveform (often a sinusoid) whose period is controlled by the digital word contained in the Frequency Control Register. The sampled, digital waveform is converted to an analog waveform by the DAC. The output reconstruction filter rejects the spectral replicas produced by the zero-order hold inherent in the analog conversion process.
Performance
A DDS has many advantages over its analog counterpart, the phase-locked loop (PLL), including much better frequency agility, improved phase noise, and precise control of the output phase across frequency switching transitions. Disadvantages include spurious responses mainly due to truncation effects in the NCO, crossing s |
https://en.wikipedia.org/wiki/Tank%20classification | Tank classification is a taxonomy of identifying either the intended role or weight class of tanks. The classification by role was used primarily during the developmental stage of the national armoured forces, and referred to the doctrinal and force structure utility of the tanks based on design emphasis. The weight classification is used in the same way truck classification is used, and is intended to accommodate logistic requirements of the tanks.
Many classification systems have been used over a hundred years of tank history. An early division in the definition of roles was between infantry tanks intended to focus on supporting infantry in the assault, and cruiser tanks intended for classic cavalry missions of exploitation, screening and reconnaissance. As World War II progressed, the separation of "infantry" and "cruiser" roles generally disappeared and the "universal tank" started to take over.
Classification has always been determined by the prevailing theories of armoured warfare, which have been altered in turn by rapid advances in technology. No one classification system works across all periods or all nations; in particular, weight-based classification was inconsistent between countries and eras.
With the worldwide adoption of the modern main battle tank designs, which favour a modular universal design, these sorts of classifications are mostly eliminated from modern terminology. All main battle tanks are typically armed with weapons with similar characteristics |
https://en.wikipedia.org/wiki/Leonor%20Michaelis | Leonor Michaelis (16 January 1875 – 8 October 1949) was a German biochemist, physical chemist, and physician, known for his work with Maud Menten on enzyme kinetics in 1913, as well as for work on enzyme inhibition, pH and quinones.
Early life and education
Leonor Michaelis was born in Berlin, Germany, on 16 January 1875, and graduated from the humanistic Koellnisches Gymnasium in 1893 after passing the Abiturienten Examen. He was Jewish. It was here that Michaelis's interest in physics and chemistry was first sparked as he was encouraged by his teachers to utilize the relatively unused laboratories at his school.
With concerns about the financial stability of a pure scientist, he commenced his study of medicine at Berlin University in 1893. Among his instructors were Emil du Bois-Reymond for physiology, Emil Fischer for chemistry, and Oscar Hertwig for histology and embryology.
During his time at Berlin University, Michaelis worked in the lab of Oscar Hertwig, even receiving prize for a paper on the histology of milk secretion. Michaelis's doctoral thesis work on cleavage determination in frog eggs led him to write a textbook on embryology. Through his work at Hertwig's lab, Michaelis came to know Paul Ehrlich and his work on blood cytology; he worked as Ehrlich's private research assistant from 1898 to 1899.
He passed his physician's examination in 1896 in Freiburg, and then moved to Berlin, where he received his doctorate in 1897. After receiving his medical degree, Mi |
https://en.wikipedia.org/wiki/Hamiltonian%20system | A Hamiltonian system is a dynamical system governed by Hamilton's equations. In physics, this dynamical system describes the evolution of a physical system such as a planetary system or an electron in an electromagnetic field. These systems can be studied in both Hamiltonian mechanics and dynamical systems theory.
Overview
Informally, a Hamiltonian system is a mathematical formalism developed by Hamilton to describe the evolution equations of a physical system. The advantage of this description is that it gives important insights into the dynamics, even if the initial value problem cannot be solved analytically. One example is the planetary movement of three bodies: while there is no closed-form solution to the general problem, Poincaré showed for the first time that it exhibits deterministic chaos.
Formally, a Hamiltonian system is a dynamical system characterised by the scalar function , also known as the Hamiltonian. The state of the system, , is described by the generalized coordinates and , corresponding to generalized momentum and position respectively. Both and are real-valued vectors with the same dimension N. Thus, the state is completely described by the 2N-dimensional vector
and the evolution equations are given by Hamilton's equations:
The trajectory is the solution of the initial value problem defined by Hamilton's equations and the initial condition .
Time-independent Hamiltonian systems
If the Hamiltonian is not explicitly time-dependent, i.e. if , |
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