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https://en.wikipedia.org/wiki/List%20of%20truck%20types | This List of truck types is intended to classify trucks and to provide links to articles on the various types. The three main classifications for road truck by weight are light trucks, medium trucks, and heavy trucks. Above this there are specialised very heavy trucks and transporters such as heavy haulers for moving oversized loads, and off-road heavy haul trucks used in and mining which are too large for highway use without escorts and special permits.
Small trucks
Mini trucks, small Commercial vehicles used for delivering light loads over short distances.
Light trucks
Light trucks are larger than mini trucks but smaller than medium trucks. In the US, they are defined as weighing between . There is no smaller classification.
Minivan
Sport utility vehicle
Pickup truck/Ute
Panel truck
Canopy express
Panel van
Tow truck (may also be a medium or heavy truck)
Medium trucks
Medium trucks are larger than light but smaller than heavy trucks. In the US, they are defined as weighing between . In North America, a medium-duty truck is larger than a heavy-duty pickup truck or full-size van. Some trucks listed as medium also are made in heavy versions.
Box truck
Van
Cutaway van chassis
Medium Duty Truck such as Ford F-650 in North America
Medium Standard Truck
Platform truck
Flatbed truck (may also be light-duty trucks)
Stake bed truck (may also be light-duty trucks)
Firetruck (may also be a heavy truck)
Recreational Vehicle or Motorhome
The following are not types of trucks bu |
https://en.wikipedia.org/wiki/Bed%20load | The term bed load or bedload describes particles in a flowing fluid (usually water) that are transported along the stream bed. Bed load is complementary to suspended load and wash load.
Bed load moves by rolling, sliding, and/or saltating (hopping).
Generally, bed load downstream will be smaller and more rounded than bed load upstream (a process known as downstream fining). This is due in part to attrition and abrasion which results from the stones colliding with each other and against the river channel, thus removing the rough texture (rounding) and reducing the size of the particles. However, selective transport of sediments also plays a role in relation to downstream fining: smaller-than average particles are more easily entrained than larger-than average particles, since the shear stress required to entrain a grain is linearly proportional to the diameter of the grain. However, the degree of size selectivity is restricted by the hiding effect described by Parker and Klingeman (1982), wherein larger particles protrude from the bed whereas small particles are shielded and hidden by larger particles, with the result that nearly all grain sizes become entrained at nearly the same shear stress.
Experimental observations suggest that a uniform free-surface flow over a cohesion-less plane bed is unable to entrain sediments below a critical value of the ratio between measures of hydrodynamic (destabilizing) and gravitational (stabilizing)
forces acting on sediment particles, |
https://en.wikipedia.org/wiki/AE2 | AE2 may refer to:
, E-class submarine of the Royal Australian Navy
Aero Ae 02, a design of Czechoslovakian plane
Anion Exchanger 2, transport protein
Ape Escape 2
A size designation for Constantinian bronze coins
Applied Energistics 2, a popular mod for the video game Minecraft
Aminoestradiol, a synthetic estrogen |
https://en.wikipedia.org/wiki/Doomsday%20rule | The Doomsday rule, Doomsday algorithm or Doomsday method is an algorithm of determination of the day of the week for a given date. It provides a perpetual calendar because the Gregorian calendar moves in cycles of 400 years. The algorithm for mental calculation was devised by John Conway in 1973, drawing inspiration from Lewis Carroll's perpetual calendar algorithm. It takes advantage of each year having a certain day of the week upon which certain easy-to-remember dates, called the doomsdays, fall; for example, the last day of February, 4/4, 6/6, 8/8, 10/10, and 12/12 all occur on the same day of the week in any year.
Applying the Doomsday algorithm involves three steps: Determination of the anchor day for the century, calculation of the anchor day for the year from the one for the century, and selection of the closest date out of those that always fall on the doomsday, e.g., 4/4 and 6/6, and count of the number of days (modulo 7) between that date and the date in question to arrive at the day of the week. The technique applies to both the Gregorian calendar and the Julian calendar, although their doomsdays are usually different days of the week.
The algorithm is simple enough that it can be computed mentally. Conway could usually give the correct answer in under two seconds. To improve his speed, he practiced his calendrical calculations on his computer, which was programmed to quiz him with random dates every time he logged on.
Anchor days for some contemporary years
Do |
https://en.wikipedia.org/wiki/Frederick%20A.%20Shannon | Frederick Albert Shannon Jr. (May 4, 1921 – August 31, 1965) was an American herpetologist and medical doctor.
He was born in Mount Pleasant, Iowa, the son of historian Fred Albert Shannon and Edna M. (Jones) Shannon.
In 1939, Shannon moved to Champaign, Illinois, and began studying zoology at the University of Illinois, where he got a B.A. in zoology in 1943. He then started studying medicine and got an M.D. in 1947. He practiced for one year at the St. Joseph's Hospital in Phoenix, Arizona, before going back to Illinois for some post-graduate herpetology work. In 1949 he moved to Wickenburg, Arizona.
Between 1951 and 1953, Shannon was sent as a lieutenant to Korea, where although on active service in a war zone he still found opportunities to collect many reptile specimens. Back in the U.S., he published many articles on venomous snake bites, venomology, and herpetology. From 1956 on, he collected specimens mainly in Mexico.
He died from the bite of a Mojave rattlesnake he had attempted to catch.
Shannon is commemorated in the scientific names of two lizards: Sceloporus shannonorum and Urosaurus graciosus shannoni. The specific name, shannonorum, which is genitive plural, honors both Shannon and his wife.
References
American herpetologists
1921 births
1965 deaths
Deaths due to snake bites
American military personnel of the Korean War
Deaths due to animal attacks in the United States
United States Army officers
Physicians from Arizona
People from Mount Pleasant, Iowa
|
https://en.wikipedia.org/wiki/Diffusion%20of%20responsibility | Diffusion of responsibility is a sociopsychological phenomenon whereby a person is less likely to take responsibility for action or inaction when other bystanders or witnesses are present. Considered a form of attribution, the individual assumes that others either are responsible for taking action or have already done so.
The diffusion of responsibility refers to the decreased responsibility of action each member of a group feels when they are part of a group. For example, in emergency situations, individuals feel less responsibility to respond or call for help if they know that there are others also watching the situation -
if they know they are a part of the group of witnesses. In other group settings (in which a group is appointed to complete a task or reach a certain goal), the diffusion of responsibility manifests itself as the decreased responsibility each member feels to contribute and work hard towards accomplishing the task or goal. The diffusion of responsibility is present in almost all groups, but to varying degrees, and can be mitigated by reducing group size, defining clear expectations, and increasing accountability.
Assumption of responsibility tends to decrease when the potential helping group is larger, resulting in little aiding behavior demonstrated by the bystander(s). Causes range from psychological effects of anonymity to differences in sex. Implication of behaviours related to diffusion of responsibility can be threatening as there have been increas |
https://en.wikipedia.org/wiki/Human%20Genome%20Organisation | The Human Genome Organisation (HUGO) is a non-profit organization founded in 1988. HUGO represents an international coordinating scientific body in response to initiatives such as the Human Genome Project. HUGO has four active committees, including the HUGO Gene Nomenclature Committee (HGNC), and the HUGO Committee on Ethics, Law and Society (CELS).
History
HUGO was established at the first meeting on genome mapping and sequencing at Cold Spring Harbor in 1988. The idea of starting the organization stemmed from South African biologist Sydney Brenner, who is best known for his significant contributions to work on the genetic code and other areas of molecular biology, as well as winning the 2002 Nobel Prize in Physiology or Medicine.
A Founding Council was elected at the meeting with a total of 42 scientists from 17 different countries, with Victor A. McKusick serving as founding President. In 2016, HUGO was located at the EWHA Womans University in Seoul, South Korea. In 2020, the HUGO headquarters moved to Farmington, Connecticut, US.
HUGO has convened a Human Genome Meeting (HGM) every year since 1996.
In partnership with geneticist Yuan-Tsong Chen and Alice Der-Shan Chen, founders of the Chen Foundation, HUGO presents the Chen Award to those with research accomplishments in human genetics and genomics in Asia Pacific.
In 2020, HUGO merged with the Human Genomic Variation Society (HGVS) and Human Variome Project (HVP).
Presidents
Ada Hamosh (US) – 2023–present
Charl |
https://en.wikipedia.org/wiki/Languages%20of%20the%20Philippines | There are some 130 to 195 languages spoken in the Philippines, depending on the method of classification. Almost all are Malayo-Polynesian languages native to the archipelago. A number of Spanish-influenced creole varieties generally called Chavacano along with some local varieties of Chinese are also spoken in certain communities. The 1987 constitution designates Filipino, a standardized version of Tagalog, as the national language and an official language along with English. Filipino is regulated by Commission on the Filipino Language and serves as a lingua franca used by Filipinos of various ethnolinguistic backgrounds.
Republic Act 11106 declares Filipino Sign Language or FSL as the country's official sign language and as the Philippine government's official language in communicating with the Filipino Deaf.
While Filipino is used for communication across the country's diverse linguistic groups and in popular culture, the government operates mostly using English. Including second-language speakers, there are more speakers of Filipino than English in the Philippines. The other regional languages are given official auxiliary status in their respective places according to the constitution but particular languages are not specified. Some of these regional languages are also used in education.
The indigenous scripts of the Philippines (such as the Kulitan, Tagbanwa and others) are used very little; instead, Philippine languages are today written in the Latin script because o |
https://en.wikipedia.org/wiki/Nicholas%20Aylward%20Vigors | Nicholas Aylward Vigors (1785 – 26 October 1840) was an Irish zoologist and politician. He popularized the classification of birds on the basis of the quinarian system.
Early life
Vigors was born at Old Leighlin, County Carlow on 1785 as first son from Capt. Nicholas Aylward Vigors which served in 29th (Worcestershire) Regiment and, his first wife, Catherine Vigors, daughter of Solomon Richards of Solsborough. He matriculated at Trinity College, Oxford in November 1803 before he was admitted at Lincoln's Inn in November 1806. Without completing his studies, he served in the army during the Peninsular War from 1809 to 1811 and wounded in Battle of Barossa on 5 March 1811. Though, he haven't completed his studies yet, he still published "An inquiry into the nature and extent of poetick licence" in London at 1810. He then returned to Oxford to continued his studies and achieved his Bachelor of Arts on 1817 and Master of Arts on 1818. He practiced as a barrister and became a Doctor of Civil Law in 1832.
Zoology
Vigors was a co-founder of the Zoological Society of London in 1826, and its first secretary until 1833. In that year, he founded what became the Royal Entomological Society of London. He was a fellow of the Linnean Society and the Royal Society. He was the author of 40 papers, mostly on ornithology. He described 110 species of birds, enough to rank him among the top 30 bird authors historically. He provided the text for John Gould's A Century of Birds from the H |
https://en.wikipedia.org/wiki/Pyramidal%20cell | Pyramidal cells, or pyramidal neurons, are a type of multipolar neuron found in areas of the brain including the cerebral cortex, the hippocampus, and the amygdala. Pyramidal cells are the primary excitation units of the mammalian prefrontal cortex and the corticospinal tract. Pyramidal neurons are also one of two cell types where the characteristic sign, Negri bodies, are found in post-mortem rabies infection. Pyramidal neurons were first discovered and studied by Santiago Ramón y Cajal. Since then, studies on pyramidal neurons have focused on topics ranging from neuroplasticity to cognition.
Structure
One of the main structural features of the pyramidal neuron is the conic shaped soma, or cell body, after which the neuron is named. Other key structural features of the pyramidal cell are a single axon, a large apical dendrite, multiple basal dendrites, and the presence of dendritic spines.
Apical dendrite
The apical dendrite rises from the apex of the pyramidal cell's soma. The apical dendrite is a single, long, thick dendrite that branches several times as distance from the soma increases and extends towards the cortical surface.
Basal dendrite
Basal dendrites arise from the base of the soma. The basal dendritic tree consists of three to five primary dendrites. As distance increases from the soma, the basal dendrites branch profusely.
Pyramidal cells are among the largest neurons in the brain. Both in humans and rodents, pyramidal cell bodies (somas) average around 20 |
https://en.wikipedia.org/wiki/Hydrocyclone | Hydrocyclones are a type of cyclonic separators that separate product phases mainly on basis of differences in gravity with aqueous solutions as the primary feed fluid.
As opposed to dry or dust cyclones, which separate solids from gasses, hydrocyclones separate solids or different phase fluids from the bulk fluid. A hydrocyclone comprises a cylindrical shaped feed part with tangential feed; an overflow part with vortex finder; a conical part with an apex. A cyclone has no moving parts.
Working principle
Product is fed into the hydrocyclone tangentially under a certain pressure. This creates a centrifugal movement, pushing the heavier phase outward and downward alongside the wall of the conical part. The decreasing diameter in the conical part increases the speed and so enhances the separation. Finally, the concentrated solids are discharged through the apex. The vortex finder in the overflow part creates a fast rotating upward spiral movement of the fluid in the centre of the conically shaped housing. The fluid is discharged through the overflow outlet.
Cyclone parameters
The following parameters are decisive for good cyclone operation:
the design
the specific weight difference between the two product phases
the shape of the solids
the speed of the feed
the density of the medium
the counter pressure at the overflow and apex
Areas of application
The main areas of application for hydrocyclones are:
Mineral processing industry Hydrocyclones are frequently utilized in t |
https://en.wikipedia.org/wiki/Lorna%20Wing | Lorna Gladys Wing (7 October 1928 – 6 June 2014) was an English psychiatrist. She was a pioneer in the field of childhood developmental disorders, who advanced understanding of autism worldwide, introduced the term Asperger syndrome in 1976 and was involved in founding the National Autistic Society (NAS) in the UK.
Early life
Lorna Gladys Tolchard was born at Gillingham, Kent to Royal Navy engineer Bernard Newberry Tolchard (1898–1968) and Gladys Ethel (died 1962), née Whittell. Following education at Chatham Grammar School for Girls, she commenced medical training at University College Hospital in 1949. After qualifying as a psychiatrist, her first post was at the Institute of Psychiatry, Maudsley Hospital, London (now part of King's College London).
Career
Although Wing trained as a medical doctor, specialising in psychiatry, her focus narrowed to childhood developmental disorders in 1959. At that time autism was thought to affect around 5 in 10,000 children, but its prevalence in the 2010s was considered to be around 1 in 100 following the awareness raised by Wing and her followers. Her research, particularly with her collaborator Judith Gould, now underpins thinking in the field of autism. They initiated the Camberwell Case Register to record all patients using psychiatric services in this area of London. The data accumulated by this innovative approach gave Wing the basis for her influential insight that autism formed a spectrum, rather than clearly differentiated dis |
https://en.wikipedia.org/wiki/C8H10N4O2 | The molecular formula C8H10N4O2 may refer to:
Enprofylline, a xanthine derivative used in the treatment of asthma.
Caffeine, the world's most widely consumed psychoactive drug, present in coffee, chocolate, black and green tea, energy drinks, and more. |
https://en.wikipedia.org/wiki/Peppered%20moth%20evolution | The evolution of the peppered moth is an evolutionary instance of directional colour change in the moth population as a consequence of air pollution during the Industrial Revolution. The frequency of dark-coloured moths increased at that time, an example of industrial melanism. Later, when pollution was reduced, the light-coloured form again predominated. Industrial melanism in the peppered moth was an early test of Charles Darwin's natural selection in action, and it remains a classic example in the teaching of evolution. In 1978, Sewall Wright described it as "the clearest case in which a conspicuous evolutionary process has actually been observed."
The dark-coloured or melanic form of the peppered moth (var. carbonaria) was rare, though a specimen had been collected by 1811. After field collection in 1848 from Manchester, an industrial city in England, the frequency of the variety was found to have increased drastically. By the end of the 19th century it almost completely outnumbered the original light-coloured type (var. typica), with a record of 98% in 1895. The evolutionary importance of the moth was only speculated upon during Darwin's lifetime. It was 14 years after Darwin's death, in 1896, that J. W. Tutt presented it as a case of natural selection. Because of this, the idea spread widely, and more people came to believe in Darwin's theory.
Bernard Kettlewell was the first to investigate the evolutionary mechanism behind peppered moth adaptation, between 1953 and 1 |
https://en.wikipedia.org/wiki/Milchem | Milchem Inc. was formed in 1963 to manufacture and market drilling fluids and oilfield chemicals.
The company's home office was located at 3920 Essex Lane in Houston, Texas. It had regional sales and service offices throughout North America and the world.
Background
In 1971, Milchem was acquired by Baker Oil Tools.
In 1985, Baker announced that it would combine its Houston-based Milchem Drilling Fluids subsidiary with competitor New Orleans-based Newpark Drilling Fluids forming Milpark, with Baker getting 64% of the merged company and Newpark Resources Inc. parent of Newpark Drilling Fluids taking 36%. Combined revenues at the time of the merger were estimated at $225 million per year.
In 1987, Baker merged with Hughes forming Baker Hughes and Hughes Drilling Fluids was merged into Milpark.
In 1993, Milpark became a product line within Baker Hughes INTEQ.
In 2004, Baker Hughes Drilling Fluids was established as a stand-alone division of Baker Hughes.
References
Chemical companies of the United States |
https://en.wikipedia.org/wiki/RIAM | Riam or RIAM might refer to:
APBB1IP, a protein
Chao Chom Manda Riam (1770–1837), royal concubine of King Buddha Loetla Nabhalai of Siam
Halam tribe, or Riam, various tribes native to Tripura, India
Riverside International Automotive Museum, a defunct automotive museum in Riverside, California, U.S.
Royal Irish Academy of Music |
https://en.wikipedia.org/wiki/Stefan%20Mazurkiewicz | Stefan Mazurkiewicz (25 September 1888 – 19 June 1945) was a Polish mathematician who worked in mathematical analysis, topology, and probability. He was a student of Wacław Sierpiński and a member of the Polish Academy of Learning (PAU). His students included Karol Borsuk, Bronisław Knaster, Kazimierz Kuratowski, Stanisław Saks, and Antoni Zygmund. For a time Mazurkiewicz was a professor at the University of Paris; however, he spent most of his career as a professor at the University of Warsaw.
The Hahn–Mazurkiewicz theorem, a basic result on curves prompted by the phenomenon of space-filling curves, is named for Mazurkiewicz and Hans Hahn. His 1935 paper Sur l'existence des continus indécomposables is generally considered the most elegant piece of work in point-set topology.
During the Polish–Soviet War (1919–21), Mazurkiewicz as early as 1919 broke the most common Russian cipher for the Polish General Staff's cryptological agency. Thanks to this, orders issued by Soviet commander Mikhail Tukhachevsky's staff were known to Polish Army leaders. This contributed substantially, perhaps decisively, to Polish victory at the critical Battle of Warsaw and possibly to Poland's survival as an independent country.
See also
Biuro Szyfrów
List of Polish mathematicians
External links
1888 births
1945 deaths
Warsaw School of Mathematics
People from Warsaw Governorate
Polish cryptographers
Topologists
Academic staff of the University of Paris
Academic staff of the University |
https://en.wikipedia.org/wiki/Ifriqiya | Ifriqiya ( ), also known as al-Maghrib al-Adna (), was a medieval historical region comprising today's Tunisia and eastern Algeria, and Tripolitania (roughly western Libya). It included all of what had previously been the Byzantine province of Africa Proconsularis and extended beyond it, but did not include the Mauretanias.
To the south, Ifriqiya was bounded by the semi-arid lands and salt marshes named el-Djerid. The northern boundary fluctuated from as far north as Sicily to the North African coastline, and the western boundary usually reached Béjaïa. The capital was briefly Carthage, then Qayrawan (Kairouan), then Mahdia, then Tunis. The Aghlabids, from their base in Kairouan, initiated the invasion of Southern Italy beginning in 827, and established the Emirate of Sicily, which lasted until it was conquered by the Normans, and the short-lived Emirate of Bari.
History
The province of Ifriqiya was created in 703 CE when the Umayyads seized Africa from the Byzantine Empire. Although Islam existed throughout the province, there was still considerable religious tension and conflict between the invading Arabs and the native Berbers. The beliefs and perceptions of people also shifted from area to area. This contrast was at its greatest between coastal cities and villages. Muslim ownership of Ifriqiya changed hands numerous times in its history with the collapse of the Umayyads paving the way for the Aghlabids, who acted as agents of the Abbasids in Baghdad.
They were then ov |
https://en.wikipedia.org/wiki/Hadwiger%27s%20theorem | In integral geometry (otherwise called geometric probability theory), Hadwiger's theorem characterises the valuations on convex bodies in It was proved by Hugo Hadwiger.
Introduction
Valuations
Let be the collection of all compact convex sets in A valuation is a function such that and for every that satisfy
A valuation is called continuous if it is continuous with respect to the Hausdorff metric. A valuation is called invariant under rigid motions if whenever and is either a translation or a rotation of
Quermassintegrals
The quermassintegrals are defined via Steiner's formula
where is the Euclidean ball. For example, is the volume, is proportional to the surface measure, is proportional to the mean width, and is the constant
is a valuation which is homogeneous of degree that is,
Statement
Any continuous valuation on that is invariant under rigid motions can be represented as
Corollary
Any continuous valuation on that is invariant under rigid motions and homogeneous of degree is a multiple of
See also
References
An account and a proof of Hadwiger's theorem may be found in
An elementary and self-contained proof was given by Beifang Chen in
Integral geometry
Theorems in convex geometry
Probability theorems |
https://en.wikipedia.org/wiki/NMRI | NMRI may refer to:
Nuclear magnetic resonance imaging
Naval Medical Research Institute, now part of the U.S. Navy's National Naval Medical Center |
https://en.wikipedia.org/wiki/Feynman%E2%80%93Kac%20formula | The Feynman–Kac formula, named after Richard Feynman and Mark Kac, establishes a link between parabolic partial differential equations (PDEs) and stochastic processes. In 1947, when Kac and Feynman were both Cornell faculty, Kac attended a presentation of Feynman's and remarked that the two of them were working on the same thing from different directions. The Feynman–Kac formula resulted, which proves rigorously the real-valued case of Feynman's path integrals. The complex case, which occurs when a particle's spin is included, is still an open question.
It offers a method of solving certain partial differential equations by simulating random paths of a stochastic process. Conversely, an important class of expectations of random processes can be computed by deterministic methods.
Theorem
Consider the partial differential equation
defined for all and , subject to the terminal condition
where are known functions, is a parameter, and is the unknown. Then the Feynman–Kac formula tells us that the solution can be written as a conditional expectationunder the probability measure such that is an Itô process driven by the equation
with is a Wiener process (also called Brownian motion) under , and the initial condition for is .
Intuitive interpretation
Suppose we have a particle moving according to the diffusion processLet the particle incur "cost" at a rate of at location at time . Let it incur a final cost at .
Also, allow the particle to decay. If the particle is |
https://en.wikipedia.org/wiki/Exudate | An exudate is a fluid emitted by an organism through pores or a wound, a process known as exuding or exudation.
Exudate is derived from exude 'to ooze' from Latin 'to (ooze out) sweat' ( 'out' and 'to sweat').
Medicine
An exudate is any fluid that filters from the circulatory system into lesions or areas of inflammation. It can be a pus-like or clear fluid. When an injury occurs, leaving skin exposed, it leaks out of the blood vessels and into nearby tissues. The fluid is composed of serum, fibrin, and leukocytes. Exudate may ooze from cuts or from areas of infection or inflammation.
Types
Purulent or suppurative exudate consists of plasma with both active and dead neutrophils, fibrinogen, and necrotic parenchymal cells. This kind of exudate is consistent with more severe infections, and is commonly referred to as pus.
Fibrinous exudate is composed mainly of fibrinogen and fibrin. It is characteristic of rheumatic carditis, but is seen in all severe injuries such as strep throat and bacterial pneumonia. Fibrinous inflammation is often difficult to resolve due to blood vessels growing into the exudate and filling space that was occupied by fibrin. Often, large amounts of antibiotics are necessary for resolution.
Catarrhal exudate is seen in the nose and throat and is characterized by a high content of mucus.
Serous exudate (sometimes classified as serous transudate) is usually seen in mild inflammation, with relatively low protein. Its consistency resembles that of |
https://en.wikipedia.org/wiki/Proper%20convex%20function | In mathematical analysis, in particular the subfields of convex analysis and optimization, a proper convex function is an extended real-valued convex function with a non-empty domain, that never takes on the value and also is not identically equal to
In convex analysis and variational analysis, a point (in the domain) at which some given function is minimized is typically sought, where is valued in the extended real number line Such a point, if it exists, is called a of the function and its value at this point is called the () of the function. If the function takes as a value then is necessarily the global minimum value and the minimization problem can be answered; this is ultimately the reason why the definition of "" requires that the function never take as a value. Assuming this, if the function's domain is empty or if the function is identically equal to then the minimization problem once again has an immediate answer. Extended real-valued function for which the minimization problem is not solved by any one of these three trivial cases are exactly those that are called . Many (although not all) results whose hypotheses require that the function be proper add this requirement specifically to exclude these trivial cases.
If the problem is instead a maximization problem (which would be clearly indicated, such as by the function being concave rather than convex) then the definition of "" is defined in an analogous (albeit technically different) manner but with |
https://en.wikipedia.org/wiki/Chow%27s%20theorem | In mathematics, Chow's theorem may refer to a number of theorems due to Wei-Liang Chow:
Chow's theorem: The theorem that asserts that any analytic subvariety in projective space is actually algebraic.
Chow–Rashevskii theorem: In sub-Riemannian geometry, the theorem that asserts that any two points are connected by a horizontal curve.
See also
Chow's lemma
Chow's moving lemma
Zhou, Weiliang |
https://en.wikipedia.org/wiki/Suicide%20gene | In the field of genetics, a suicide gene is a gene that will cause a cell to kill itself through the process of apoptosis (programmed cell death). Activation of a suicide gene can cause death through a variety of pathways, but one important cellular "switch" to induce apoptosis is the p53 protein. Stimulation or introduction (through gene therapy) of suicide genes is a potential way of treating cancer or other proliferative diseases.
Suicide genes form the basis of a strategy for making cancer cells more vulnerable or sensitive to chemotherapy. The approach has been to attach parts of genes expressed in cancer cells to other genes for enzymes not found in mammals that can convert a harmless substance into one that is toxic to the tumor. Most suicide genes mediate this sensitivity by coding for viral or bacterial enzymes that convert an inactive drug into toxic antimetabolites that inhibit the synthesis of nucleic acid. Suicide genes must be introduced into the cells in ways that ensure their uptake and expression by as many cancer cells as possible, while limiting their expression by normal cells. Suicide gene therapy for cancer requires the vector to have the capacity to discriminate between target and non target cells, between the cancer cells and normal cells.
Apoptosis
Cell death can majorly occur by either necrosis or apoptosis. Necrosis occurs when a cell is damaged by an external force, such as poison, a bodily injury, an infection or getting cut off from blood sup |
https://en.wikipedia.org/wiki/PSC | PSC may refer to:
Business
People with Significant Control, in United Kingdom company law
Personal service corporation, in United States tax law
Protein Sciences Corporation, an American biotech company
Public Service Commission (disambiguation), regulatory bodies, with competence varying by jurisdiction
Production sharing contract, a type of contract used in the resource extraction industry
Government
Public Safety Canada
Pacific Salmon Commission
Public Service of Canada
Education
Parkwood Secondary College, Ringwood North, Victoria, Australia
Parkdale Secondary College, Mordialloc, Victoria, Australia
Peter Symonds College, Winchester, UK
Pensacola State College, Pensacola, Florida
Peru State College, Peru, Nebraska
Philippine Science Consortium, an organization of tertiary schools in the Philippines
Photography Studies College, Melbourne, Victoria, Australia
Polk State College, Polk County, Florida
Putonghua Shuiping Ceshi, Mandarin proficiency test in Mainland China
Military
psc (military), "Principal Staff Course" (British Army, and Air Force), or "Passed Staff Course" (Royal Navy)
Polar Security Cutter program, a new ship class under deve for the United States Coast Guard
Private security contractor
Places
Constellation Pisces (Psc)
Palm Springs, California, USA
Pointe-Saint-Charles, Montreal, Quebec, Canada
Politics
Centre démocrate humaniste, formerly known as the Christian Social Party (PSC)
Christian Social Party (Belgium, defunct), a |
https://en.wikipedia.org/wiki/Library%20%28biology%29 | In molecular biology, a library is a collection of DNA fragments that is stored and propagated in a population of micro-organisms through the process of molecular cloning. There are different types of DNA libraries, including cDNA libraries (formed from reverse-transcribed RNA), genomic libraries (formed from genomic DNA) and randomized mutant libraries (formed by de novo gene synthesis where alternative nucleotides or codons are incorporated). DNA library technology is a mainstay of current molecular biology, genetic engineering, and protein engineering, and the applications of these libraries depend on the source of the original DNA fragments. There are differences in the cloning vectors and techniques used in library preparation, but in general each DNA fragment is uniquely inserted into a cloning vector and the pool of recombinant DNA molecules is then transferred into a population of bacteria (a Bacterial Artificial Chromosome or BAC library) or yeast such that each organism contains on average one construct (vector + insert). As the population of organisms is grown in culture, the DNA molecules contained within them are copied and propagated (thus, "cloned").
Terminology
The term "library" can refer to a population of organisms, each of which carries a DNA molecule inserted into a cloning vector, or alternatively to the collection of all of the cloned vector molecules.
cDNA libraries
A cDNA library represents a sample of the mRNA purified from a particular source |
https://en.wikipedia.org/wiki/Edward%20Purcell | Edward Purcell may refer to:
Edward A. Purcell Jr., American historian
Edward Henry Purcell (died 1765), English organist, printer, and music publisher
Edward Mills Purcell (1912–1997), American physicist, Nobel Prize winner
Edward Purcell (musician) (1689–1740), English composer
Edward Purcell (rugby league) (born 1988), Samoan rugby league international
Teddy Purcell (Edward Purcell, born 1985), Canadian ice hockey player |
https://en.wikipedia.org/wiki/Halton%20sequence | In statistics, Halton sequences are sequences used to generate points in space for numerical methods such as Monte Carlo simulations. Although these sequences are deterministic, they are of low discrepancy, that is, appear to be random for many purposes. They were first introduced in 1960 and are an example of a quasi-random number sequence. They generalize the one-dimensional van der Corput sequences.
Example of Halton sequence used to generate points in (0, 1) × (0, 1) in R2
The Halton sequence is constructed according to a deterministic method that uses coprime numbers as its bases. As a simple example, let's take one dimension of the Halton sequence to be based on 2 and the other on 3. To generate the sequence for 2, we start by dividing the interval (0,1) in half, then in fourths, eighths, etc., which generates
,
, ,
, , , ,
, ,...
Equivalently, the nth number of this sequence is the number n written in binary representation, inverted, and written after the decimal point. This is true for any base. As an example, to find the sixth element of the above sequence, we'd write 6 = 1*2 + 1*2 + 0*2 = 110, which can be inverted and placed after the decimal point to give 0.011 = 0*2 + 1*2 + 1*2 = . So the sequence above is the same as
0.1, 0.01, 0.11, 0.001, 0.101, 0.011, 0.111, 0.0001, 0.1001,...
To generate the sequence for 3, we divide the interval (0,1) in thirds, then ninths, twenty-sevenths, etc., which generates
, , , , , , , , ,...
When we pair them |
https://en.wikipedia.org/wiki/Atmospheric%20diffraction | Atmospheric diffraction is manifested in the following principal ways:
Optical atmospheric diffraction
Radio wave diffraction is the scattering of radio frequency or lower frequencies from the Earth's ionosphere, resulting in the ability to achieve greater distance radio broadcasting.
Sound wave diffraction is the bending of sound waves, as the sound travels around edges of geometric objects. This produces the effect of being able to hear even when the source is blocked by a solid object. The sound waves bend appreciably around the solid object.
However, if the object has a diameter greater than the acoustic wavelength, a 'sound shadow' is cast behind the object where the sound is inaudible. (Note: some sound may be propagated through the object depending on material).
Optical atmospheric diffraction
When light travels through thin clouds made up of nearly uniform sized water or aerosol droplets or ice crystals, diffraction or bending of light occurs as the light is diffracted by the edges of the particles. This degree of bending of light depends on the wavelength (color) of light and the size of the particles. The result is a pattern of rings, which seem to emanate from the Sun, the Moon, a planet, or another astronomical object. The most distinct part of this pattern is a central, nearly white disk. This resembles an atmospheric Airy disc but is not actually an Airy disk. It is different from rainbows and halos, which are mainly caused by refraction.
The left ph |
https://en.wikipedia.org/wiki/Hammocks%20Beach%20State%20Park | Hammocks Beach State Park is a North Carolina state park in Onslow County, North Carolina in the United States. Located near Swansboro, along the Southern Outer Banks, or Crystal Coast, the state park covers and consists mainly of Bear Island. The park also owns three smaller islands, Dudley, Huggins and Jones, located in the nearby mouth of the White Oak River. After a recently completed deal, acres on the mainland were added to the park.
Bear Island
Bear Island is four miles long with a south-facing beach. It is characterized by an extensive dune system, a pocket of maritime forest, and a shrub thicket and marsh on the northern sound side, of the island. It is popular with daytrippers, boaters, kayakers and campers. While it serves a recreational function, with a new bathhouse and primitive camping sites, the vast majority of the island is wild and undisturbed. Most of the animals on Bear Island flew or swam through tidal creeks and marshes to make their home on the island. Fresh water is scarce and only found in a few ponds in the forest between some dunes. Recent hurricanes have had a considerable impact on the oceanfront beach/dune system.
A ferry service runs from the Hammocks Beach State Park headquarters on the mainland to Bear Island via Cow Channel. While the ride, which some 200,000 people a year take, is only 15 minutes long, it is narrow and winding. The channel has increasingly become more difficult to navigate at low tide since 1996 due to sand migration |
https://en.wikipedia.org/wiki/Seismic%20moment | Seismic moment is a quantity used by seismologists to measure the size of an earthquake. The scalar seismic moment is defined by the equation
, where
is the shear modulus of the rocks involved in the earthquake (in pascals (Pa), i.e. newtons per square meter)
is the area of the rupture along the geologic fault where the earthquake occurred (in square meters), and
is the average slip (displacement offset between the two sides of the fault) on (in meters).
thus has dimensions of torque, measured in newton meters. The connection between seismic moment and a torque is natural in the body-force equivalent representation of seismic sources as a double-couple (a pair of force couples with opposite torques): the seismic moment is the torque of each of the two couples. Despite having the same dimensions as energy, seismic moment is not a measure of energy. The relations between seismic moment, potential energy drop and radiated energy are indirect and approximative.
The seismic moment of an earthquake is typically estimated using whatever information is available to constrain its factors. For modern earthquakes, moment is usually estimated from ground motion recordings of earthquakes known as seismograms. For earthquakes that occurred in times before modern instruments were available, moment may be estimated from geologic estimates of the size of the fault rupture and the slip.
Seismic moment is the basis of the moment magnitude scale introduced by Hiroo Kanamori, which is |
https://en.wikipedia.org/wiki/Tractography | In neuroscience, tractography is a 3D modeling technique used to visually represent nerve tracts using data collected by diffusion MRI. It uses special techniques of magnetic resonance imaging (MRI) and computer-based diffusion MRI. The results are presented in two- and three-dimensional images called tractograms.
In addition to the long tracts that connect the brain to the rest of the body, there are complicated neural circuits formed by short connections among different cortical and subcortical regions. The existence of these tracts and circuits has been revealed by histochemistry and biological techniques on post-mortem specimens. Nerve tracts are not identifiable by direct exam, CT, or MRI scans. This difficulty explains the paucity of their description in neuroanatomy atlases and the poor understanding of their functions.
The most advanced tractography algorithm can produce 90% of the ground truth bundles, but it still contains a substantial amount of invalid results.
MRI technique
Tractography is performed using data from diffusion MRI. The free water diffusion is termed "isotropic" diffusion. If the water diffuses in a medium with barriers, the diffusion will be uneven, which is termed anisotropic diffusion. In such a case, the relative mobility of the molecules from the origin has a shape different from a sphere. This shape is often modeled as an ellipsoid, and the technique is then called diffusion tensor imaging. Barriers can be many things: cell membranes, axo |
https://en.wikipedia.org/wiki/Membrane%20transport | In cellular biology, membrane transport refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them. The regulation of passage through the membrane is due to selective membrane permeability – a characteristic of biological membranes which allows them to separate substances of distinct chemical nature. In other words, they can be permeable to certain substances but not to others.
The movements of most solutes through the membrane are mediated by membrane transport proteins which are specialized to varying degrees in the transport of specific molecules. As the diversity and physiology of the distinct cells is highly related to their capacities to attract different external elements, it is postulated that there is a group of specific transport proteins for each cell type and for every specific physiological stage. This differential expression is regulated through the differential transcription of the genes coding for these proteins and its translation, for instance, through genetic-molecular mechanisms, but also at the cell biology level: the production of these proteins can be activated by cellular signaling pathways, at the biochemical level, or even by being situated in cytoplasmic vesicles. The cell membrane regulates the transport of materials entering and exiting the cell.
Background
Thermodynamically the flow of substances from |
https://en.wikipedia.org/wiki/Archaeogastropoda | Archaeogastropoda (also known as Aspidobranchia) was a taxonomic order of sea snails used in older classifications of gastropods, i.e. snails and slugs. Archeogastropoda are marine prosobranch gastropod mollusks, mainly herbivores, typically having two gills and a double-chambered heart, with the eggs and sperm discharged directly into the water. They were traditionally regarded as a relatively primitive group.
This older classification of the gastropods is based on the classification of Johannes Thiele (1925). This classification was not based on true phylogenetic relationships, but on more general affinities between the groups. In the last few years, two new cladistic taxonomies of the gastropods have been published (in 1997 and 2005). This has led to an extensive reclassification of gastropod taxa. The taxon Archaeogastropoda was found to be a paraphyletic group, and therefore unacceptable in a strictly cladistic classification.
In the 1997 classification, most of the former Archaeogastropoda were included in:
subclass Eogastropoda
order Patellogastropoda (limpets)
subclass Orthogastropoda
Superorder Vetigastropoda Salvini-Plawen, 1989
Superorder Neritaemorphi Koken, 1896 (with the order Neritopsina Cox & Knight, 1960).
A more detailed classification can be found on Gastropoda.
Older system of classification
Order Archaeogastropoda
Superfamily Pleurotomariacea
Family Pleurotomariidae
Family Haliotidae
Family Scissurellidae
Superfamily Fissurellacea
Family Fissurelli |
https://en.wikipedia.org/wiki/Cynthia%20Breazeal | Cynthia Breazeal is an American robotics scientist and entrepreneur. She is a former chief scientist and chief experience officer of Jibo, a company she co-founded in 2012 that developed personal assistant robots. Currently, she is a professor of media arts and sciences at MIT and the director of the Personal Robots group at the Media Lab. Her most recent work has focused on the theme of living everyday life in the presence of AI, and gradually gaining insight into the long-term impacts of social robots.
Early life and education
As the daughter of two scientists, she had early access to the fields of computer science and engineering. Under the guidance of her parents, Breazeal earned a B.Sc in electrical and computer engineering from the University of California, Santa Barbara, in 1989; her M.S. in 1993; and her Sc.D. in 2000 in electrical engineering and computer science, both from MIT. After watching a NASA robot, she decided to switch her focus to social robotics.
She developed the robot Kismet as a doctoral thesis under Rodney Brooks, which looked into the expressive social exchange between humans and humanoid robots. Kismet, as well as other robots Breazeal co-developed while a graduate student at the MIT Artificial Intelligence Lab, can now be seen at the MIT Museum. Notable examples include the upper torso humanoid robot, Cog; and the insect-like robot, Hannibal. In the early 2000s, she worked on Leonard, Aida, Autom and Huggable.
MIT career
Breazeal is a profess |
https://en.wikipedia.org/wiki/List%20of%20algorithm%20general%20topics | This is a list of algorithm general topics.
Analysis of algorithms
Ant colony algorithm
Approximation algorithm
Best and worst cases
Big O notation
Combinatorial search
Competitive analysis
Computability theory
Computational complexity theory
Embarrassingly parallel problem
Emergent algorithm
Evolutionary algorithm
Fast Fourier transform
Genetic algorithm
Graph exploration algorithm
Heuristic
Hill climbing
Implementation
Las Vegas algorithm
Lock-free and wait-free algorithms
Monte Carlo algorithm
Numerical analysis
Online algorithm
Polynomial time approximation scheme
Problem size
Pseudorandom number generator
Quantum algorithm
Random-restart hill climbing
Randomized algorithm
Running time
Sorting algorithm
Search algorithm
Stable algorithm (disambiguation)
Super-recursive algorithm
Tree search algorithm
See also
List of algorithms for specific algorithms
List of computability and complexity topics for more abstract theory
List of complexity classes, complexity class
List of data structures.
Mathematics-related lists |
https://en.wikipedia.org/wiki/Quantum%20algorithm | In quantum computing, a quantum algorithm is an algorithm which runs on a realistic model of quantum computation, the most commonly used model being the quantum circuit model of computation. A classical (or non-quantum) algorithm is a finite sequence of instructions, or a step-by-step procedure for solving a problem, where each step or instruction can be performed on a classical computer. Similarly, a quantum algorithm is a step-by-step procedure, where each of the steps can be performed on a quantum computer. Although all classical algorithms can also be performed on a quantum computer, the term quantum algorithm is usually used for those algorithms which seem inherently quantum, or use some essential feature of quantum computation such as quantum superposition or quantum entanglement.
Problems which are undecidable using classical computers remain undecidable using quantum computers. What makes quantum algorithms interesting is that they might be able to solve some problems faster than classical algorithms because the quantum superposition and quantum entanglement that quantum algorithms exploit probably cannot be efficiently simulated on classical computers (see Quantum supremacy).
The best-known algorithms are Shor's algorithm for factoring and Grover's algorithm for searching an unstructured database or an unordered list. Shor's algorithms runs much (almost exponentially) faster than the best-known classical algorithm for factoring, the general number field sieve. Gro |
https://en.wikipedia.org/wiki/Rodney%20Brooks | Rodney Allen Brooks (born 30 December 1954) is an Australian roboticist, Fellow of the Australian Academy of Science, author, and robotics entrepreneur, most known for popularizing the actionist approach to robotics. He was a Panasonic Professor of Robotics at the Massachusetts Institute of Technology and former director of the MIT Computer Science and Artificial Intelligence Laboratory. He is a founder and former Chief Technical Officer of iRobot and co-Founder, Chairman and Chief Technical Officer of Rethink Robotics (formerly Heartland Robotics) and currently is the co-founder and Chief Technical Officer of Robust.AI (founded in 2019).
Life
Brooks received a M.A. in pure mathematics from Flinders University of South Australia. In 1981, he received a PhD in Computer Science from Stanford University under the supervision of Thomas Binford. He has held research positions at Carnegie Mellon University and MIT and a faculty position at Stanford University. He joined the faculty of MIT in 1984. He was Panasonic Professor of Robotics at the Massachusetts Institute of Technology. He was director of the MIT Computer Science and Artificial Intelligence Laboratory (1997–2007), previously the "Artificial Intelligence Laboratory".
In 1997, Brooks and his work were featured in the film Fast, Cheap & Out of Control.
Brooks became a member of the National Academy of Engineering in 2004 for contributions to the foundations and applications of robotics, including the establishment of con |
https://en.wikipedia.org/wiki/Numerical%20Recipes | Numerical Recipes is the generic title of a series of books on algorithms and numerical analysis by William H. Press, Saul A. Teukolsky, William T. Vetterling and Brian P. Flannery. In various editions, the books have been in print since 1986. The most recent edition was published in 2007.
Overview
The Numerical Recipes books cover a range of topics that include both classical numerical analysis (interpolation, integration, linear algebra, differential equations, and so on), signal processing (Fourier methods, filtering), statistical treatment of data, and a few topics in machine learning (hidden Markov model, support vector machines). The writing style is accessible and has an informal tone. The emphasis is on understanding the underlying basics of techniques, not on the refinements that may, in practice, be needed to achieve optimal performance and reliability. Few results are proved with any degree of rigor, although the ideas behind proofs are often sketched, and references are given. Importantly, virtually all methods that are discussed are also implemented in a programming language, with the code printed in the book. Each version is keyed to a specific language.
According to the publisher, Cambridge University Press, the Numerical Recipes books are historically the all-time best-selling books on scientific programming methods. In recent years, Numerical Recipes books have been cited in the scientific literature more than 3000 times per year according to ISI Web o |
https://en.wikipedia.org/wiki/Shimon%20Even | Shimon Even (; June 15, 1935 – May 1, 2004) was an Israeli computer science researcher. His main topics of interest included algorithms, graph theory and cryptography. He was a member of the Computer Science Department at the Technion since 1974. Shimon Even was the PhD advisor of Oded Goldreich, a prominent cryptographer.
Books
Algorithmic Combinatorics, Macmillan, 1973.
Graph Algorithms, Computer Science Press, 1979. .
See also
Oblivious transfer
External links
Memorial page
Bibliography on DBLP
Prof. Even's "genealogy" (PDF)
1935 births
2004 deaths
Modern cryptographers
Graph theorists
Israeli computer scientists
Israeli cryptographers
Harvard University alumni
Even Shimon
Burials at Yarkon Cemetery |
https://en.wikipedia.org/wiki/Coimage | In algebra, the coimage of a homomorphism
is the quotient
of the domain by the kernel.
The coimage is canonically isomorphic to the image by the first isomorphism theorem, when that theorem applies.
More generally, in category theory, the coimage of a morphism is the dual notion of the image of a morphism. If , then a coimage of (if it exists) is an epimorphism such that
there is a map with ,
for any epimorphism for which there is a map with , there is a unique map such that both and
See also
Quotient object
Cokernel
References
Abstract algebra
Isomorphism theorems
Category theory
pl:Twierdzenie o izomorfizmie#Pierwsze twierdzenie |
https://en.wikipedia.org/wiki/Haboush%27s%20theorem | In mathematics Haboush's theorem, often still referred to as the Mumford conjecture, states that for any semisimple algebraic group G over a field K, and for any linear representation ρ of G on a K-vector space V, given v ≠ 0 in V that is fixed by the action of G, there is a G-invariant polynomial F on V, without constant term, such that
F(v) ≠ 0.
The polynomial can be taken to be homogeneous, in other words an element of a symmetric power of the dual of V, and if the characteristic is p>0 the degree of the polynomial can be taken to be a power of p.
When K has characteristic 0 this was well known; in fact Weyl's theorem on the complete reducibility of the representations of G implies that F can even be taken to be linear. Mumford's conjecture about the extension to prime characteristic p was proved by W. J. , about a decade after the problem had been posed by David Mumford, in the introduction to the first edition of his book Geometric Invariant Theory.
Applications
Haboush's theorem can be used to generalize results of geometric invariant theory from characteristic 0, where they were already known, to characteristic p>0. In particular Nagata's earlier results together with Haboush's theorem show that if a reductive group (over an algebraically closed field) acts on a finitely generated algebra then the fixed subalgebra is also finitely generated.
Haboush's theorem implies that if G is a reductive algebraic group acting regularly on an affine algebraic variety, then dis |
https://en.wikipedia.org/wiki/Genotoxicity | Genotoxicity is the property of chemical agents that damage the genetic information within a cell causing mutations, which may lead to cancer. While genotoxicity is often confused with mutagenicity, all mutagens are genotoxic, but some genotoxic substances are not mutagenic. The alteration can have direct or indirect effects on the DNA: the induction of mutations, mistimed event activation, and direct DNA damage leading to mutations. The permanent, heritable changes can affect either somatic cells of the organism or germ cells to be passed on to future generations. Cells prevent expression of the genotoxic mutation by either DNA repair or apoptosis; however, the damage may not always be fixed leading to mutagenesis.
To assay for genotoxic molecules, researchers assay for DNA damage in cells exposed to the toxic substrates. This DNA damage can be in the form of single- and double-strand breaks, loss of excision repair, cross-linking, alkali-labile sites, point mutations, and structural and numerical chromosomal aberrations. The compromised integrity of the genetic material has been known to cause cancer. As a consequence, many sophisticated techniques including Ames Assay, in vitro and in vivo Toxicology Tests, and Comet Assay have been developed to assess the chemicals' potential to cause DNA damage that may lead to cancer.
Mechanism
Genotoxic substances induce damage to the genetic material in the cells through interactions with the DNA sequence and structure. For exampl |
https://en.wikipedia.org/wiki/Bifid%20cipher | In classical cryptography, the bifid cipher is a cipher which combines the Polybius square with transposition, and uses fractionation to achieve diffusion. It was invented around 1901 by Felix Delastelle.
Operation
First, a mixed alphabet Polybius square is drawn up, where the I and the J share their position:
1 2 3 4 5
1 B G W K Z
2 Q P N D S
3 I O A X E
4 F C L U M
5 T H Y V R
The message is converted to its coordinates in the usual manner, but they are written vertically beneath:
F L E E A T O N C E
4 4 3 3 3 5 3 2 4 3
1 3 5 5 3 1 2 3 2 5
They are then read out in rows:
4 4 3 3 3 5 3 2 4 3 1 3 5 5 3 1 2 3 2 5
Then divided up into pairs again, and the pairs turned back into letters using the square:
44 33 35 32 43 13 55 31 23 25
U A E O L W R I N S
In this way, each ciphertext character depends on two plaintext characters, so the bifid is a digraphic cipher, like the Playfair cipher. To decrypt, the procedure is simply reversed.
Longer messages are first broken up into blocks of fixed length, called the period, and the above
encryption procedure is applied to each block. One way to detect the period uses bigram statistics on ciphertext letters separated by half the period. For even periods, p, ciphertext letters
at a distance of p/2 are influenced by two plaintext letters, but for odd periods, p, ciphertext letters at distances of p/2 (rounded either up or down) are influenced by three plaintext letters. Thus, odd periods are more secure than even |
https://en.wikipedia.org/wiki/Paley%E2%80%93Wiener%20theorem | In mathematics, a Paley–Wiener theorem is any theorem that relates decay properties of a function or distribution at infinity with analyticity of its Fourier transform. The theorem is named for Raymond Paley (1907–1933) and Norbert Wiener (1894–1964). The original theorems did not use the language of distributions, and instead applied to square-integrable functions. The first such theorem using distributions was due to Laurent Schwartz. These theorems heavily rely on the triangle inequality (to interchange the absolute value and integration).
Holomorphic Fourier transforms
The classical Paley–Wiener theorems make use of the holomorphic Fourier transform on classes of square-integrable functions supported on the real line. Formally, the idea is to take the integral defining the (inverse) Fourier transform
and allow to be a complex number in the upper half-plane. One may then expect to differentiate under the integral in order to verify that the Cauchy–Riemann equations hold, and thus that defines an analytic function. However, this integral may not be well-defined, even for in ; indeed, since is in the upper half plane, the modulus of grows exponentially as ; so differentiation under the integral sign is out of the question. One must impose further restrictions on in order to ensure that this integral is well-defined.
The first such restriction is that be supported on : that is, . The Paley–Wiener theorem now asserts the following: The holomorphic Fourier trans |
https://en.wikipedia.org/wiki/Martensitic%20stainless%20steel | Martensitic stainless steel is a type of stainless steel alloy that has a martensite crystal structure. It can be hardened and tempered through aging and heat treatment. The other main types of stainless steel are austenitic, ferritic, duplex, and precipitation hardened.
History
In 1912, Harry Brearley of the Brown-Firth research laboratory in Sheffield, England, while seeking a corrosion-resistant alloy for gun barrels, discovered and subsequently industrialized a martensitic stainless steel alloy. The discovery was announced two years later in a January 1915 newspaper article in The New York Times. Brearly applied for a U.S. patent during 1915. This was later marketed under the "Staybrite" brand by Firth Vickers in England and was used for the new entrance canopy for the Savoy Hotel in 1929 in London.
The characteristic body-centered tetragonal martensite microstructure was first observed by German microscopist Adolf Martens around 1890. In 1912, Elwood Haynes applied for a U.S. patent on a martensitic stainless steel alloy. This patent was not granted until 1919.
Overview
Martensitic stainless steels can be high- or low-carbon steels built around the composition of iron, 12% up to 17% chromium, carbon from 0.10% (Type 410) up to 1.2% (Type 440C):
Up to about 0.4%C they are used mostly for their mechanical properties in applications such as pumps, valves, and shafts.
Above 0.4%C they are used mostly for their wear resistance, such as in cutlery surgical blades, pla |
https://en.wikipedia.org/wiki/Mizmar%20%28instrument%29 | In Arabic music, a mizmār (; plural مَزَامِير mazāmīr) is any single or double reed wind instrument. In Egypt, the term mizmar usually refers to the conical shawm that is called zurna in Turkey and Armenia.
Mizmar is also a term used for a group of musicians, usually a duo or trio, that play a mizmar instrument along with an accompaniment of one or two double-sided bass drums, known in Arabic as tabl baladi or simply tabl.
Mizmars are usually played in Egypt at either weddings or as an accompaniment to belly dancers. At Egyptian weddings, the Mizmar Baldi is accompanied with a belly dancer to greet the bride and groom.
In Lebanon, the Palestinian Territories, and Syria, it is influenced by the Anatolian/Armenian zurna, a higher-pitched version of the mizmar, and may also be known in those countries as a zamr (زمر) or zamour, as well as mizmar. In Algeria a similar instrument is called ghaita or rhaita (غيطة). Along with belly dancing, the mizmar may accompany the dabke, a folkloric line dance done in Lebanon, Syria, Palestine, and Iraq.
See also
Mizmar (dance)
References
External links
Mizmar. Dominik Photo Images of the making
Middle Eastern culture
Single oboes with conical bore
Arabic musical instruments
Ancient Egyptian musical instruments |
https://en.wikipedia.org/wiki/Zurna | The zurna (Armenian: զուռնա zuṙna; Old Armenian: սուռնայ suṙnay; Albanian: surle/surla; Persian: karna/Kornay/surnay; Macedonian: зурла/сурла zurla/surla; Bulgarian: зурна/зурла; Serbian: зурла/zurla; Assyrian: ܙܘܪܢܐ/zurna; Tat: zurna; Turkish: zurna; Kurdish: zirne; Greek: ζουρνας; Azerbaijani: zurna; Sinhalese: හොරණෑව[horaṇǣva]) is a double reed wind instrument played in central Eurasia, West Asia, Sri Lanka and parts of North Africa. It is usually accompanied by a davul (bass drum) in Armenian, Anatolian and Assyrian folk music.
Characteristics and history
The zurna, like the duduk and kaval, is a woodwind instrument used to play folk music.
The zurna is made from the slow-growing and hardwood of fruit trees such as plum or apricot (Prunus armeniaca). There are several different types of zurnas. The most typical is the Armenian zurna. The longest (and lowest-pitched) is the kaba zurna, used in Bulgaria, the shortest (and highest-pitched), which can be made of bone, is the zurna played in Messolonghi and other villages of Aetolia-Acarnania region in Greece.
The zurna, a relative of the oboe, is found almost everywhere where the common reed grows because it uses a short cylindrical reed that is tied to a conical brass tube on one end, flattened to a narrow slit on the other end as a source of the sound.
It requires high pressure to give any tone at all and when it does, it is almost constantly loud, high pitched, sharp, and piercing.
The need for high pressure makes it |
https://en.wikipedia.org/wiki/Silicosis | Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. It is marked by inflammation and scarring in the form of nodular lesions in the upper lobes of the lungs. It is a type of pneumoconiosis. Silicosis (particularly the acute form) is characterized by shortness of breath, cough, fever, and cyanosis (bluish skin). It may often be misdiagnosed as pulmonary edema (fluid in the lungs), pneumonia, or tuberculosis. Using workplace controls, silicosis is almost always a preventable disease.
Silicosis resulted in at least 43,000 deaths globally in 2013, down from at least 50,000 deaths in 1990.
The name silicosis (from the Latin silex, or flint) was originally used in 1870 by Achille Visconti (1836–1911), prosector in the Ospedale Maggiore of Milan. The recognition of respiratory problems from breathing in dust dates to ancient Greeks and Romans. Agricola, in the mid-16th century, wrote about lung problems from dust inhalation in miners. In 1713, Bernardino Ramazzini noted asthmatic symptoms and sand-like substances in the lungs of stone cutters. Less than 10 years after its introduction, in 1720, as a raw material to the British ceramics industry the negative effects of milled calcined flint on the lungs of workers had been noted. With industrialization, as opposed to hand tools, came increased production of dust. The pneumatic hammer drill was introduced in 1897 and sandblasting was introduced in about 1904, both significantly contrib |
https://en.wikipedia.org/wiki/Fluorescence%20recovery%20after%20photobleaching | Fluorescence recovery after photobleaching (FRAP) is a method for determining the kinetics of diffusion through tissue or cells. It is capable of quantifying the two-dimensional lateral diffusion of a molecularly thin film containing fluorescently labeled probes, or to examine single cells. This technique is very useful in biological studies of cell membrane diffusion and protein binding. In addition, surface deposition of a fluorescing phospholipid bilayer (or monolayer) allows the characterization of hydrophilic (or hydrophobic) surfaces in terms of surface structure and free energy.
Similar, though less well known, techniques have been developed to investigate the 3-dimensional diffusion and binding of molecules inside the cell; they are also referred to as FRAP.
Experimental setup
The basic apparatus comprises an optical microscope, a light source and some fluorescent probe. Fluorescent emission is contingent upon absorption of a specific optical wavelength or color which restricts the choice of lamps. Most commonly, a broad spectrum mercury or xenon source is used in conjunction with a color filter. The technique begins by saving a background image of the sample before photobleaching. Next, the light source is focused onto a small patch of the viewable area either by switching to a higher magnification microscope objective or with laser light of the appropriate wavelength. The fluorophores in this region receive high intensity illumination which causes their fluoresce |
https://en.wikipedia.org/wiki/Patch%20clamp | The patch clamp technique is a laboratory technique in electrophysiology used to study ionic currents in individual isolated living cells, tissue sections, or patches of cell membrane. The technique is especially useful in the study of excitable cells such as neurons, cardiomyocytes, muscle fibers, and pancreatic beta cells, and can also be applied to the study of bacterial ion channels in specially prepared giant spheroplasts.
Patch clamping can be performed using the voltage clamp technique. In this case, the voltage across the cell membrane is controlled by the experimenter and the resulting currents are recorded. Alternatively, the current clamp technique can be used. In this case, the current passing across the membrane is controlled by the experimenter and the resulting changes in voltage are recorded, generally in the form of action potentials.
Erwin Neher and Bert Sakmann developed the patch clamp in the late 1970s and early 1980s. This discovery made it possible to record the currents of single ion channel molecules for the first time, which improved understanding of the involvement of channels in fundamental cell processes such as action potentials and nerve activity. Neher and Sakmann received the Nobel Prize in Physiology or Medicine in 1991 for this work.
Basic technique
Set-up
During a patch clamp recording, a hollow glass tube known as a micropipette or patch pipette filled with an electrolyte solution and a recording electrode connected to an amplifi |
https://en.wikipedia.org/wiki/Radio%20spectrum | The radio spectrum is the part of the electromagnetic spectrum with frequencies from 3 Hz to 3,000 GHz (3 THz). Electromagnetic waves in this frequency range, called radio waves, are widely used in modern technology, particularly in telecommunication. To prevent interference between different users, the generation and transmission of radio waves is strictly regulated by national laws, coordinated by an international body, the International Telecommunication Union (ITU).
Different parts of the radio spectrum are allocated by the ITU for different radio transmission technologies and applications; some 40 radiocommunication services are defined in the ITU's Radio Regulations (RR). In some cases, parts of the radio spectrum are sold or licensed to operators of private radio transmission services (for example, cellular telephone operators or broadcast television stations). Ranges of allocated frequencies are often referred to by their provisioned use (for example, cellular spectrum or television spectrum). Because it is a fixed resource which is in demand by an increasing number of users, the radio spectrum has become increasingly congested in recent decades, and the need to utilize it more effectively is driving modern telecommunications innovations such as trunked radio systems, spread spectrum, ultra-wideband, frequency reuse, dynamic spectrum management, frequency pooling, and cognitive radio.
Limits
The frequency boundaries of the radio spectrum are a matter of convention i |
https://en.wikipedia.org/wiki/Bendixson%E2%80%93Dulac%20theorem | In mathematics, the Bendixson–Dulac theorem on dynamical systems states that if there exists a function (called the Dulac function) such that the expression
has the same sign () almost everywhere in a simply connected region of the plane, then the plane autonomous system
has no nonconstant periodic solutions lying entirely within the region. "Almost everywhere" means everywhere except possibly in a set of measure 0, such as a point or line.
The theorem was first established by Swedish mathematician Ivar Bendixson in 1901 and further refined by French mathematician Henri Dulac in 1923 using Green's theorem.
Proof
Without loss of generality, let there exist a function such that
in simply connected region . Let be a closed trajectory of the plane autonomous system in . Let be the interior of . Then by Green's theorem,
Because of the constant sign, the left-hand integral in the previous line must evaluate to a positive number. But on , and , so the bottom integrand is in fact 0 everywhere and for this reason the right-hand integral evaluates to 0. This is a contradiction, so there can be no such closed trajectory .
References
Henri Dulac (1870-1955) was a French mathematician from Fayence
Differential equations
Theorems in dynamical systems |
https://en.wikipedia.org/wiki/Light%20railway | A light railway is a railway built at lower costs and to lower standards than typical "heavy rail": it uses lighter-weight track, and may have more steep gradients and tight curves to reduce civil engineering costs. These lighter standards allow lower costs of operation, at the price of lower vehicle capacity.
Narrow gauge
thumb | right | 250px | Restored Molli railway at Kühlungsborn, Mecklenburg, Germany ()
In countries where a single standard gauge is dominant, the term light railway does not imply a narrow gauge railway. Most narrow gauge railways operate as light railways, but not all light railways need be narrow gauge. After Spooner's development of steam haulage for narrow gauge railways, the prevailing view was that the gauge should be tailored according to the traffic: "The nearer the machine is apportioned to the work it has to do the cheaper will that work be done." From the 1890s, it was recognised that cost savings could also be made in the construction and operation of a standard gauge railway: "light axle-loads and low speeds, not gauge, are the first condition of cheap construction and economical working. Gauge is quite a secondary factor." Break of gauge now became an important factor, and there was much concern over whether this would become an additional cost for the transshipment of goods, or whether this was over-emphasised compared to the amount of warehousing and handling needed anyway. The Irish railway system in particular became a good example |
https://en.wikipedia.org/wiki/List%20of%20partial%20differential%20equation%20topics | This is a list of partial differential equation topics.
General topics
Partial differential equation
Nonlinear partial differential equation
list of nonlinear partial differential equations
Boundary condition
Boundary value problem
Dirichlet problem, Dirichlet boundary condition
Neumann boundary condition
Stefan problem
Wiener–Hopf problem
Separation of variables
Green's function
Elliptic partial differential equation
Singular perturbation
Cauchy–Kovalevskaya theorem
H-principle
Atiyah–Singer index theorem
Bäcklund transform
Viscosity solution
Weak solution
Loewy decomposition of linear differential equations
Specific partial differential equations
Broer–Kaup equations
Burgers' equation
Euler equations
Fokker–Planck equation
Hamilton–Jacobi equation, Hamilton–Jacobi–Bellman equation
Heat equation
Laplace's equation
Laplace operator
Harmonic function
Spherical harmonic
Poisson integral formula
Klein–Gordon equation
Korteweg–de Vries equation
Modified KdV–Burgers equation
Maxwell's equations
Navier–Stokes equations
Poisson's equation
Primitive equations (hydrodynamics)
Schrödinger equation
Wave equation
Numerical methods for PDEs
Finite difference
Finite element method
Finite volume method
Boundary element method
Multigrid
Spectral method
Computational fluid dynamics
Alternating direction implicit
Related areas of mathematics
Calculus of variations
Harmonic analysis
Ordinary differential equation
Sobolev space
Partial differential equations |
https://en.wikipedia.org/wiki/Vitali%20theorem | Several theorems in mathematical analysis bear the name of Giuseppe Vitali:
Vitali covering theorem in the foundations of measure theory
Various theorems concerning convergence of families of measurable and holomorphic functions, such as Vitali convergence theorem
Vitali also proved the existence of non-measurable subsets of the real numbers, see Vitali set |
https://en.wikipedia.org/wiki/Index%20of%20evolutionary%20biology%20articles | This is a list of topics in evolutionary biology.
A
abiogenesis – adaptation – adaptive mutation – adaptive radiation – allele – allele frequency – allochronic speciation – allopatric speciation – altruism – : anagenesis – anti-predator adaptation – applications of evolution – aposematism – Archaeopteryx – aquatic adaptation – artificial selection – atavism
B
Henry Walter Bates – biological organisation – Brassica oleracea – breed
C
Cambrian explosion – camouflage – Sean B. Carroll – catagenesis – gene-centered view of evolution – cephalization – Sergei Chetverikov – chronobiology – chronospecies – clade – cladistics – climatic adaptation – coalescent theory – co-evolution – co-operation – coefficient of relationship – common descent – convergent evolution – creation–evolution controversy – cultivar – conspecific song preference
D
Darwin (unit) – Charles Darwin – Darwinism – Darwin's finches – Richard Dawkins – directed mutagenesis – Directed evolution – directional selection – Theodosius Dobzhansky – dog breeding – domestication – domestication of the horse
E
E. coli long-term evolution experiment – ecological genetics – ecological selection – ecological speciation – Endless Forms Most Beautiful – endosymbiosis – error threshold (evolution) – evidence of common descent – evolution – evolutionary arms race – evolutionary capacitance
Evolution: of ageing – of the brain – of cetaceans – of complexity – of dinosaurs – of the eye – of fish – of the horse – of insects – |
https://en.wikipedia.org/wiki/Thomas%20Kurtz | Thomas Kurtz may refer to:
Thomas E. Kurtz (born 1928), professor of mathematics and computer scientist
Thomas G. Kurtz (born 1941), professor of mathematics and statistics
Tom Kurtz, rhythm guitarist for the band Starstruck that recorded the hit song Black Betty#Ram Jam version |
https://en.wikipedia.org/wiki/Ecoregions%20in%20the%20Philippines | The Philippine archipelago is one of the world's great reservoirs of biodiversity and endemism. The archipelago includes over 7000 islands, and a total land area of 300,780 km².
The Philippines was never connected to mainland Asia via land bridges, so the flora and fauna of the islands had to cross ocean straits to reach the Philippines. The Philippines is part of the Indomalayan realm, and its flora and fauna is mostly derived from tropical Asia. Botanically, the Philippines are part of Malesia, a floristic province that includes the Malay Peninsula, Indonesia, and New Guinea. Most of the Malesian flora is derived from tropical Asia, including the dipterocarps, which are the characteristic tree of the Philippine forests. Elements of the Antarctic flora, which originated in the ancient southern hemisphere supercontinent of Gondwana, are also present, including ancient conifers like podocarps (Podocarpus, Nageia, Sundacarpus) and araucarias (Agathis).
The ecoregions of the Philippines are defined primarily by the sea levels during the Ice Ages, which were 120 meters lower than at present, as billions of gallons of water were locked away in huge continental ice sheets. This drop in sea level connected many presently separate islands into larger islands, which allowed for exchanges of flora and fauna:
Greater Luzon included Luzon, Catanduanes, Marinduque, Polillo, and several small islands.
Greater Mindanao included Mindanao, Basilan, Bohol, Leyte, Samar, and adjacent small |
https://en.wikipedia.org/wiki/Canon%20EF-S%20lens%20mount | The Canon EF-S lens mount is a derivative of the EF lens mount created for some Canon digital single-lens reflex cameras with APS-C sized image sensors. It was released in 2003. Cameras with the EF-S mount are backward compatible with the EF lenses and, as such, have a flange focal distance of 44.0 mm. Such cameras, however, have more clearance, allowing lens elements to be closer to the sensor than in the EF mount. Only Canon cameras released after 2003 with APS-C sized sensors support the EF-S mount.
The "S" in EF-S has variously been described by Canon as coming from either "Small image circle" (the lens projects a smaller image circle than normal EF lenses to match the sensor), or "Short back focus" (the smaller mirror used in APS-C cameras also allows optical elements to protrude further into the camera body, reducing the minimum distance between the sensor and the back element of the lens). The combination of a smaller sensor and shorter back focal length distance enhances the possibilities for wide angle and very wide angle lenses. Such lenses designed for the EF-S mount can be made smaller, lighter (containing less glass), faster (larger aperture) and less expensive.
Although not all Canon EF-S lenses use this short back focal length, they cannot be mounted on DSLRs with sensors larger than APS-C. However, some lenses produced by third-party manufacturers may feature the standard EF mount if they do not have the shorter back focal length but only have a small image |
https://en.wikipedia.org/wiki/Lipid%20raft | The plasma membranes of cells contain combinations of glycosphingolipids, cholesterol and protein receptors organised in glycolipoprotein lipid microdomains termed lipid rafts. Their existence in cellular membranes remains somewhat controversial. It has been proposed that they are specialized membrane microdomains which compartmentalize cellular processes by serving as organising centers for the assembly of signaling molecules, allowing a closer interaction of protein receptors and their effectors to promote kinetically favorable interactions necessary for the signal transduction. Lipid rafts influence membrane fluidity and membrane protein trafficking, thereby regulating neurotransmission and receptor trafficking. Lipid rafts are more ordered and tightly packed than the surrounding bilayer, but float freely within the membrane bilayer. Although more common in the cell membrane, lipid rafts have also been reported in other parts of the cell, such as the Golgi apparatus and lysosomes.
Properties
One key difference between lipid rafts and the plasma membranes from which they are derived is lipid composition. Research has shown that lipid rafts contain 3 to 5-fold the amount of cholesterol found in the surrounding bilayer. Also, lipid rafts are enriched in sphingolipids such as sphingomyelin, which is typically elevated by 50% compared to the plasma membrane. To offset the elevated sphingolipid levels, phosphatidylcholine levels are decreased which results in similar choline |
https://en.wikipedia.org/wiki/Hosting | Hosting may refer to:
To act as the organizer or master of ceremonies for an event
Self-hosting (compilers), software distribution which provides all necessary source code to enable itself to be re-compiled from scratch
Internet hosting service, including:
Web hosting service, service that makes the website accessible via the World Wide Web
Shared web hosting service, web hosting service where many websites reside on one webserver
Software as a service, model in which software is licensed on a subscription basis and is centrally hosted
Dedicated hosting service, Internet hosting in which the client leases an entire server
One-click hosting
See also
Host (disambiguation)
Hosted desktop
Hosted Exchange
Hosted payload
Hosting environment |
https://en.wikipedia.org/wiki/Satellite%20%28biology%29 | A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication. Satellites can be divided into two major classes: satellite viruses and satellite nucleic acids. Satellite viruses, which are most commonly associated with plants, are also found in mammals, arthropods, and bacteria. They encode structural proteins to enclose their genetic material, which are therefore distinct from the structural proteins of their helper viruses. Satellite nucleic acids, in contrast, do not encode their own structural proteins, but instead are encapsulated by proteins encoded by their helper viruses. The genomes of satellites range upward from 359 nucleotides in length for satellite tobacco ringspot virus RNA (STobRV).
Most viruses have the capability to use host enzymes or their own replication machinery to independently replicate their own viral RNA. Satellites, in contrast, are completely dependent on a helper virus for replication. The symbiotic relationship between a satellite and a helper virus to catalyze the replication of a satellite genome is also dependent on the host to provide components like replicases to carry out replication.
A satellite virus of mamavirus that inhibits the replication of its host has been termed a virophage. However, the usage of this term remains controversial due to the lack of fundamental differences between virophages and classical satellite viruses.
History and discovery
The tobacco necrosis virus |
https://en.wikipedia.org/wiki/Lam%C3%A9%27s%20special%20quartic | Lamé's special quartic, named after Gabriel Lamé, is the graph of the equation
where . It looks like a rounded square with "sides" of length and centered on the origin. This curve is a squircle centered on the origin, and it is a special case of a superellipse.
Because of Pierre de Fermat's only surviving proof, that of the n = 4 case of Fermat's Last Theorem, if r is rational there is no non-trivial rational point (x, y) on this curve (that is, no point for which both x and y are non-zero rational numbers).
References
Equations |
https://en.wikipedia.org/wiki/Hypovolemic%20shock | Hypovolemic shock is a form of shock caused by severe hypovolemia (insufficient blood volume or extracellular fluid in the body). It could be the result of severe dehydration through a variety of mechanisms or blood loss. Hypovolemic shock is a medical emergency; if left untreated, the insufficient blood flow can cause damage to organs, leading to multiple organ failure.
In treating hypovolemic shock, it is important to determine the cause of the underlying hypovolemia, which may be the result of bleeding or other fluid losses. To minimize ischemic damage to tissues, treatment involves quickly replacing lost blood or fluids, with consideration of both rate and the type of fluids used.
Tachycardia, a fast heart rate, is typically the first abnormal vital sign. When resulting from blood loss, trauma is the most common root cause, but severe blood loss can also happen in various body systems without clear traumatic injury. The body in hypovolemic shock prioritizes getting oxygen to the brain and heart, which reduces blood flow to nonvital organs and extremities, causing them to grow cold, look mottled, and exhibit delayed capillary refill. The lack of adequate oxygen delivery ultimately leads to a worsening increase in the acidity of the blood (acidosis). The "lethal triad" of ways trauma can lead to death is acidosis, hypothermia, and coagulopathy. It is possible for trauma to cause clotting problems even without resuscitation efforts.
Damage control resuscitation is based o |
https://en.wikipedia.org/wiki/Tennis%20elbow | Tennis elbow, also known as lateral epicondylitis or enthesopathy of the extensor carpi radialis origin, is an enthesopathy (attachment point disease) of the origin of the extensor carpi radialis brevis on the lateral epicondyle. The outer part of the elbow becomes painful and tender. The pain may also extend into the back of the forearm. Onset of symptoms is generally gradual although they can seem sudden and be misinterpreted as an injury. Golfer's elbow is a similar condition that affects the inside of the elbow.
Enthesopathies are idiopathic, meaning science has not yet determined the cause. Enthesopathies are most common in middle age (ages 35 to 60).
It is often stated that the condition is caused by excessive use of the muscles of the back of the forearm, but this is not supported by experimental evidence and is a common misinterpretation or unhelpful thought about symptoms. It may be associated with work or sports, classically racquet sports (including paddle sports), but most people with the condition are not exposed to these activities. The diagnosis is based on the symptoms and examination. Medical imaging is not particularly useful. Signs consistent with the diagnosis include pain when a subject tries to bend back the wrist against resistance.
The natural history of untreated enthesopathy is resolution over a period of 1–2 years. Palliative (symptoms alleviating) treatment may include pain medications such as NSAIDS or acetaminophen (paracetamol), a wrist brac |
https://en.wikipedia.org/wiki/Stromal%20cell-derived%20factor%201 | The stromal cell-derived factor 1 (SDF-1), also known as C-X-C motif chemokine 12 (CXCL12), is a chemokine protein that in humans is encoded by the CXCL12 gene on chromosome 10. It is ubiquitously expressed in many tissues and cell types. Stromal cell-derived factors 1-alpha and 1-beta are small cytokines that belong to the chemokine family, members of which activate leukocytes and are often induced by proinflammatory stimuli such as lipopolysaccharide, TNF, or IL1. The chemokines are characterized by the presence of 4 conserved cysteines that form 2 disulfide bonds. They can be classified into 2 subfamilies. In the CC subfamily, the cysteine residues are adjacent to each other. In the CXC subfamily, they are separated by an intervening amino acid. The SDF1 proteins belong to the latter group. CXCL12 signaling has been observed in several cancers. The CXCL12 gene also contains one of 27 SNPs associated with increased risk of coronary artery disease.
Structure
Gene
The CXCL12 gene resides on chromosome 10 at the band 10q11.1 and contains 9 exons. This gene produces 7 isoforms through alternative splicing.
Protein
This protein belongs to the intercrine alpha (chemokine CXC) family. SDF-1 is produced in two forms, SDF-1α/CXCL12a and SDF-1β/CXCL12b, by alternate splicing of the same gene. Chemokines are characterized by the presence of four conserved cysteines, which form two disulfide bonds. The CXCL12 proteins belong to the group of CXC chemokines, whose initial pair of c |
https://en.wikipedia.org/wiki/Dimitri%20Riabouchinsky | Dimitri Pavlovitch Riabouchinsky (,6 November 1882– 22 August 1962) was a Russian fluid dynamicist noted for his discovery of the Riabouchinsky solid technique. With the aid of Nikolay Zhukovsky he founded the Institute of Aerodynamics in 1904, the first in Europe. He also independently discovered equivalent results to the Buckingham Pi Theorem in 1911. Riabouchinsky left Russia following the October Revolution and his short-term arrest, spending the rest of his life in Paris, yet he never accepted the French citizenship and used his Nansen passport up till death. He was a member of the Moscow State University, the University of Paris, the French Academy of Sciences as well as one of the co-founders of the Russian Higher Technical School in France. Over 200 scientific works were published during his lifetime. He was an Invited Speaker of the ICM in 1920 at Strasbourg, in 1928 at Bologna, and in 1932 at Zurich.
Notes
External links
Рябушинский Дмитрий Павлович
Воспоминания о Рябушинском. Лекция из цикла «Выдающиеся ученые — математики и механики» в мемориальном кабинете-музее Л. И. Седова
«Российский научный некрополь за рубежом» РЯБУШИНСКИЙ (Riabouchinsky, Riaboushinsky) Дмитрий Павлович
Dimitri Pavlovitch Riabouchinsky (1882-1962)
1882 births
1962 deaths
Scientists from Moscow
Scientists from Paris
Fluid dynamicists
Members of the French Academy of Sciences
Academic staff of Moscow State University
Academic staff of the University of Paris
Aerodynamicists
Aviation |
https://en.wikipedia.org/wiki/Angioedema | Angioedema is an area of swelling (edema) of the lower layer of skin and tissue just under the skin or mucous membranes. The swelling may occur in the face, tongue, larynx, abdomen, or arms and legs. Often it is associated with hives, which are swelling within the upper skin. Onset is typically over minutes to hours.
The underlying mechanism typically involves histamine or bradykinin. The version related to histamine is due to an allergic reaction to agents such as insect bites, foods, or medications. The version related to bradykinin may occur due to an inherited problem known as C1 esterase inhibitor deficiency, medications known as angiotensin-converting enzyme inhibitors, or a lymphoproliferative disorder.
Treatment to protect the airway may include intubation or cricothyroidotomy. Histamine-related angioedema can be treated with antihistamines, corticosteroids, and epinephrine. In those with bradykinin-related disease a C1 esterase inhibitor, ecallantide, or icatibant may be used. Fresh frozen plasma may be used instead. In the United States the disease affects about 100,000 people a year.
Signs and symptoms
The skin of the face, normally around the mouth, and the mucosa of the mouth and/or throat, as well as the tongue, swell over the period of minutes to hours. The swelling can also occur elsewhere, typically in the hands. The swelling can be itchy or painful. There may also be slightly decreased sensation in the affected areas due to compression of the nerves. U |
https://en.wikipedia.org/wiki/Glycocalyx | The glycocalyx (: glycocalyces or glycocalyxes), also known as the pericellular matrix and sometime cell coat, is a glycoprotein and glycolipid covering that surrounds the cell membranes of bacteria, epithelial cells, and other cells. It was described in a review article in 1970.
Animal epithelial cells have a fuzz-like coating on the external surface of their plasma membranes. This viscous coating is the glycocalyx that consists of several carbohydrate moieties of membrane glycolipids and glycoproteins, which serve as backbone molecules for support. Generally, the carbohydrate portion of the glycolipids found on the surface of plasma membranes helps these molecules contribute to cell–cell recognition, communication, and intercellular adhesion.
The glycocalyx is a type of identifier that the body uses to distinguish between its own healthy cells and transplanted tissues, diseased cells, or invading organisms. Included in the glycocalyx are cell-adhesion molecules that enable cells to adhere to each other and guide the movement of cells during embryonic development. The glycocalyx plays a major role in regulation of endothelial vascular tissue, including the modulation of red blood cell volume in capillaries.
The term was initially applied to the polysaccharide matrix coating epithelial cells, but its functions have been discovered to go well beyond that.
In vascular endothelial tissue
The glycocalyx is located on the apical surface of vascular endothelial cells which lin |
https://en.wikipedia.org/wiki/Messier%2034 | Messier 34 (also known as M34 or NGC 1039) is a large and relatively near open cluster in Perseus. It was probably discovered by Giovanni Batista Hodierna before 1654 and included by Charles Messier in his catalog of comet-like objects in 1764. Messier described it as, "A cluster of small stars a little below the parallel of γ (Andromedae). In an ordinary telescope of 3 feet one can distinguish the stars."
Based on the distance modulus of 8.38, it is about away. For stars ranging from 0.12 to 1 solar mass (), the cluster has about 400. It spans about 35′ on the sky which translates to a true radius of 7.5 light years at such distance. The cluster is just visible to the naked eye in very dark conditions, well away from city lights. It is possible to see it in binoculars when light pollution is low.
The age of this cluster lies between the ages of the Pleiades open cluster at 100 million years and the Hyades open cluster at 800 million years. Specifically, comparison between noted stellar spectra and the values predicted by stellar evolutionary models suggest 200–250 million years. This is roughly the age at which stars with half a solar mass enter the main sequence. By comparison, stars like the Sun enter the main sequence after 30 million years.
The average proportion of elements with higher atomic numbers than helium is termed the metallicity by astronomers. This is expressed by the logarithm of the ratio of iron to hydrogen, compared to the same proportion in the Sun. F |
https://en.wikipedia.org/wiki/S-layer | An S-layer (surface layer) is a part of the cell envelope found in almost all archaea, as well as in many types of bacteria.
The S-layers of both archaea and bacteria consists of a monomolecular layer composed of only one (or, in a few cases, two) identical proteins or glycoproteins. This structure is built via self-assembly and encloses the whole cell surface. Thus, the S-layer protein can represent up to 15% of the whole protein content of a cell. S-layer proteins are poorly conserved or not conserved at all, and can differ markedly even between related species. Depending on species, the S-layers have a thickness between 5 and 25 nm and possess identical pores with 2–8 nm in diameter.
The terminology “S-layer” was used the first time in 1976. The general use was accepted at the "First International Workshop on Crystalline Bacterial Cell Surface Layers, Vienna (Austria)" in 1984, and in the year 1987 S-layers were defined at the European Molecular Biology Organization Workshop on “Crystalline Bacterial Cell Surface Layers”, Vienna as “Two-dimensional arrays of proteinaceous subunits forming surface layers on prokaryotic cells” (see "Preface", page VI in Sleytr "et al. 1988"). For a brief summary on the history of S-layer research see "References".
Location of S-layers
In Gram-negative bacteria, S-layers are associated to the lipopolysaccharides via ionic, carbohydrate–carbohydrate, protein–carbohydrate interactions and/or protein–protein interactions.
In Gram-positive |
https://en.wikipedia.org/wiki/Fimbria | A fimbria (plural fimbriae, adjective fimbriate) is a Latin word that literally means "fringe." Fimbria or Fimbriate may refer to:
Fimbria (bacteriology), a proteinaceous appendage in many gram-negative bacteria that is thinner and shorter than a flagellum
Fimbria (bivalve), a genus of clams
Fimbria (female reproductive system), a fringe of tissue near the ovary leading to the fallopian tube
Fimbria (neuroanatomy), a prominent band of white matter along the medial edge of the hippocampus in the brain
Fimbriate, a botanical term meaning "fringed" e.g. petals
Fimbriation, in heraldry and vexillology, the use of contrasting strips to separate similar colours
Roman name
Gaius Flavius Fimbria (consul 104 BCE), consul of the Roman Republic with Gaius Marius
Gaius Flavius Fimbria (cavalry prefect) (died 84 BCE), son of the consul of 104 BCE
See also |
https://en.wikipedia.org/wiki/Endolymph | Endolymph is the fluid contained in the membranous labyrinth of the inner ear. The major cation in endolymph is potassium, with the values of sodium and potassium concentration in the endolymph being 0.91 mM and 154 mM, respectively. It is also called Scarpa's fluid, after Antonio Scarpa.
Structure
The inner ear has two parts: the bony labyrinth and the membranous labyrinth. The membranous labyrinth is contained within the bony labyrinth, and within the membranous labyrinth is a fluid called endolymph. Between the outer wall of the membranous labyrinth and the wall of the bony labyrinth is the location of perilymph.
Composition
Perilymph and endolymph have unique ionic compositions suited to their functions in regulating electrochemical impulses of hair cells. The electric potential of endolymph is ~80-90 mV more positive than perilymph due to a higher concentration of K compared to Na.
The main component of this unique extracellular fluid is potassium, which is secreted from the stria vascularis. The high potassium content of the endolymph means that potassium, not sodium, is carried as the de-polarizing electric current in the hair cells. This is known as the mechano-electric transduction (MET) current.
Endolymph has a high positive potential (80–120 mV in the cochlea), relative to other nearby fluids such as perilymph, due to its high concentration of positively charged ions. It is mainly this electrical potential difference that allows potassium ions to flow into t |
https://en.wikipedia.org/wiki/SimLife | SimLife: The Genetic Playground is a video game produced by Maxis in 1992. The concept of the game is to simulate an ecosystem; players may modify the genetics of the plants and animals that inhabit the virtual world. The point of this game is to experiment and create a self-sustaining ecosystem. SimLife was re-released in 1993 as part of the SimClassics Volume 1 compilation, alongside SimCity Classic and SimAnt for PC, Mac and Amiga.
Development
The producers of SimLife refer to it as "The Genetic Playground". The game allows users to explore the interaction of life-forms and environments. Users can manipulate the genetics of both plants and animals to determine whether these new species could survive in the Earth's various environments. Players can also create new worlds with distinctive environments to see how certain species (earth's species or their own) fare within them.
SimLife gives players the power to:
Create and modify worlds.
Create and modify plants and animals at the genetic level. Exclusive animals appearing in this game are the Killer Penguin, the Monkeyphant, and the Orgot.
Design environments and ecosystems.
Study genetics in action.
Simulate and control evolution.
Change the physics of the universe in your computer.
Reception
Computer Gaming World in 1993 praised SimLife, stating that "By neatly bridging the gap between entertainment and education, SL brings the engrossing science of genetics within reach of any interested person".
Games Finder |
https://en.wikipedia.org/wiki/Fathers%27%20Day%20%281997%20film%29 | Fathers' Day is a 1997 American comedy film directed by Ivan Reitman and starring Robin Williams, Billy Crystal, Julia Louis-Dreyfus, and Nastassja Kinski. It is a remake of the 1983 French film Les Compères.
In the film, Collette Andrews (Kinski) enlists two former lovers, cynical lawyer Jack Lawrence (Crystal) and lonely, ex-hippie, suicidal writer Dale Putley (Williams) to help her search for her runaway teenage son Scott by telling each man that he is the father. When Jack and Dale run into each other and find out what is happening, they work together to find Scott and determine the identity of the actual father.
The film features an appearance by the musical groups Sugar Ray and The Muffs. It was a critical and commercial failure.
Plot
16-year-old Scott Andrews runs away from home with his girlfriend, Nikki. His mother Collette visits her ex-boyfriend, lawyer Jack Lawrence, telling him that Scott is really his son and wants him to find the boy: Jack refuses at first, but changes his mind when work keeps him in San Francisco overnight.
Meanwhile, writer Dale Putley is planning suicide when he gets a phone call from Collette, of whom he is another ex, and she tells him the same story.
Both men start their search with Russ, Nikki's father. Dale and Jack get little help from him, but it does lead to them meeting each other. Mistakenly assuming that they each have a different missing son, they think "both boys" are mixed up with Nikki. They decide to team up.
Jack and D |
https://en.wikipedia.org/wiki/Gene%20gun | In genetic engineering, a gene gun or biolistic particle delivery system is a device used to deliver exogenous DNA (transgenes), RNA, or protein to cells. By coating particles of a heavy metal with a gene of interest and firing these micro-projectiles into cells using mechanical force, an integration of desired genetic information can be introduced into desired cells. The technique involved with such micro-projectile delivery of DNA is often referred to as biolistics, short for "biological ballistics".
This device is able to transform almost any type of cell and is not limited to the transformation of the nucleus; it can also transform organelles, including plastids and mitochondria.
Gene gun design
The gene gun was originally a Crosman air pistol modified to fire dense tungsten particles. It was invented by John C Sanford, Ed Wolf, and Nelson Allen at Cornell University along with Ted Klein of DuPont between 1983 and 1986. The original target was onions (chosen for their large cell size), and the device was used to deliver particles coated with a marker gene which would relay a signal if proper insertion of the DNA transcript occurred. Genetic transformation was demonstrated upon observed expression of the marker gene within onion cells.
The earliest custom manufactured gene guns (fabricated by Nelson Allen) used a 22 caliber nail gun cartridge to propel a polyethylene cylinder (bullet) down a 22 caliber Douglas barrel. A droplet of the tungsten powder coated with geneti |
https://en.wikipedia.org/wiki/Messier%2036 | Messier 36 or M36, also known as NGC 1960, is an open cluster of stars in the somewhat northern Auriga constellation. It was discovered by Giovanni Batista Hodierna before 1654, who described it as a nebulous patch. The cluster was independently re-discovered by Guillaume Le Gentil in 1749, then Charles Messier observed it in 1764 and added it to his catalogue. It is about 1,330 pc (4,340 light years) away from Earth. The cluster is very similar to the Pleiades cluster (M45), and if as far away it would be of similar apparent magnitude.
This cluster has an angular diameter of and a core radius of . It has a mass of roughly and a linear tidal radius of . Based upon photometry, the age of the cluster has been estimated by Wu et al. (2009) as 25.1 Myr and Myr by Bell et al. (2013). The luminosity of the stars that have not yet depleted their lithium implies an age of Myr, in good agreement with these older estimates.
M36 includes ten stars with a visual magnitude brighter than 10, and 178 down to magnitude 14. 38 members display an infrared excess, with one being particularly high. There is one candidate B-type variable star, of 9th magnitude.
A 2020 study of the variable stars in the cluster estimated a new closer distance of 3,800 light years from Earth.
A young stellar object with an outflow, associated with the infrared source IRAS 05327+3404 was discovered in optical observations of M36. The outflow is nicknamed "Holoea", Hawaiian for "flowing gas". Despite appearin |
https://en.wikipedia.org/wiki/Messier%2037 | Messier 37 (also known as M37 or NGC 2099) is the brightest and richest open cluster in the constellation Auriga. It was discovered by the Italian astronomer Giovanni Battista Hodierna before 1654. M37 was missed by French astronomer Guillaume Le Gentil when he rediscovered M36 and M38 in 1749. French astronomer Charles Messier independently rediscovered M37 in September 1764 but all three of these clusters were recorded by Hodierna. It is classified as Trumpler type I,1,r or I,2,r.
M37 exists in the antipodal direction, opposite from the Galactic Center as seen from Earth, so is in one of the nearby outer arms. Specifically it is still close enough to be in our own. Estimates of its age range from 347 million to 550 million years. It has 1,500 times the mass of the Sun () and contains over 500 identified stars, with roughly 150 stars brighter than magnitude 12.5. M37 has at least a dozen red giants and its hottest surviving main sequence star is of stellar classification B9 V. The abundance of elements other than hydrogen and helium, what astronomers term metallicity, is similar to, if not slightly higher than, the abundance in the Sun. As of 2022, it contains only the third known planetary nebula associated with an open cluster.
At its estimated distance of around from Earth, the cluster's angular diameter of 24 arcminutes corresponds to a physical extent of about . The tidal radius of the cluster, where external gravitational perturbations begin to have a significant in |
https://en.wikipedia.org/wiki/Messier%2038 | Messier 38 or M38, also known as NGC 1912 or Starfish Cluster, is an open cluster of stars in the constellation of Auriga. It was discovered by Giovanni Batista Hodierna before 1654 and independently found by Le Gentil in 1749. The open clusters M36 and M37, also discovered by Hodierna, are often grouped together with M38. Distance is about away from Earth. The open cluster NGC 1907 lies nearby on the sky, but the two are most likely just experiencing a fly-by, having originated in different parts of the galaxy.
The cluster's brightest stars form a pattern resembling the Greek letter Pi or, according to Webb, an "oblique cross". Walter Scott Houston described its appearance as follows:
Photographs usually show a departure from circularity, a feature quite evident to visual observers. Older reports almost always mention a cross shape, which seems more pronounced with small instruments. A view with a 24-inch reflector on a fine Arizona night showed the cluster as irregular, and the host of stars made fruitless any effort to find a geometrical figure.
At its distance of 1066 pc., its angular diameter of about 20 arc minutes corresponds to about 4.0 parsecs (13 light years), similar to that of its more distant neighbor M37. It is of intermediate age at about 290 million years. From the population of about 100 stars, this open cluster features a prominent yellow giant with the apparent magnitude +7.9 and spectral type G0 as its brightest member. This corresponds to an absolu |
https://en.wikipedia.org/wiki/Transthyretin | Transthyretin (TTR or TBPA) is a transport protein in the plasma and cerebrospinal fluid that transports the thyroid hormone thyroxine (T4) and retinol to the liver. This is how transthyretin gained its name: transports thyroxine and retinol. The liver secretes TTR into the blood, and the choroid plexus secretes TTR into the cerebrospinal fluid.
TTR was originally called prealbumin (or thyroxine-binding prealbumin) because it migrated faster than albumin on electrophoresis gels. Prealbumin was felt to be a misleading name, it is not a synthetic precursor of albumin. The alternative name TTR was proposed by DeWitt Goodman in 1981.
Transthyretin protein is encoded by the TTR gene located on the 18th chromosome.
Binding affinities
It functions in concert with two other thyroid hormone-binding proteins in the serum:
In cerebrospinal fluid TTR is the primary carrier of T4.
TTR also acts as a carrier of retinol (vitamin A) through its association with retinol-binding protein (RBP) in the blood and the CSF.
Less than 1% of TTR's T4 binding sites are occupied in blood, which is taken advantage of below to prevent TTRs dissociation, misfolding and aggregation which leads to the degeneration of post-mitotic tissue.
Numerous other small molecules are known to bind in the thyroxine binding sites, including many natural products (such as resveratrol), drugs (tafamidis, diflunisal, and flufenamic acid), and toxicants (PCB).
Structure
TTR is a 55kDa homotetramer with a dimer of dim |
https://en.wikipedia.org/wiki/Probably | Probably may refer to:
Probability, the chance that something is likely to happen or be the case
"Probably" (South Park), an episode of the TV series South Park
"Probably" (song), a song by Fool's Garden
See also
Probability (disambiguation)
Problem (disambiguation)
Pro (disambiguation) |
https://en.wikipedia.org/wiki/Pixie-bob | The Pixie-bob is a breed of domestic cat claimed to be the progeny of naturally occurring bobcat hybrids. However, DNA testing has failed to detect bobcat marker genes, and Pixie-bobs are considered wholly domestic for the purposes of ownership, cat fancy registration, and import and export. They were, however, selected and bred to look like American bobcats.
History
In the spring of 1985, Carol Ann Brewer purchased near Mount Baker, Washington, a unique male cat with a spotted coat, a short tail, and polydactyl paws. In January 1986, she rescued another male cat named Keba, which was very large, had a bobbed tail, and was reported to have been sired by a bobcat. While this cat was starving, it still weighed 17 pounds, and was so tall it reached up to Brewer's knees. Shortly after she had acquired this large male, it mated with a next door neighbor's brown spotted female cat. In April 1986, a litter was born from this mating. Brewer eventually kept one of the female kittens, named "Pixie", and after a year started a breeding program with Pixie as the foundation cat.
Over the next couple of years, Brewer introduced into her program 23 cats from around the nearby Cascade Range, that were believed by her to be born from naturally occurring matings between bobcats and domestic cats. She coined the term "Legend Cat" to refer to such cats and has since registered a trademark in the U.S. to limit the term to describe permitted outcrosses used in her breeding program. At the same t |
https://en.wikipedia.org/wiki/Messier%2047 | Messier 47 (M47 or NGC 2422) is an open cluster in the mildly southern constellation of Puppis. It was discovered by Giovanni Batista Hodierna before 1654 and in his then keynote work re-discovered by Charles Messier on 1771. It was also independently discovered by Caroline Herschel.
There is no cluster in the position indicated by Messier, which he expressed in terms of its right ascension and declination with respect to the star 2 Puppis. However, if the signs (+ and −) he wrote are swapped, the position matches. Until this equivalency was found, M47 was considered a lost Messier Object. This identification as the same thing (ad idem) only came in 1959 with a realization by Canadian astronomer T. F. Morris.
M47 is centered about 1,600 light-years away and is about 78 million years old. The member stars have been measured down to about red dwarfs at apparent magnitude 19. There are around 500 members, the brightest being HD 60855, a magnitude 5.7 Be star. The cluster is dominated by hot class B main sequence and giant stars, but a noticeable colour contrast comes from its brightest red giants.
It about a degree from Messier 46, which is much older and much further away.
Gallery
See also
List of Messier objects
References and footnotes
External links
Messier 47, SEDS Messier pages
Messier 47 Amateur Image - Waid Observatory
Messier 047
Messier 047
047
Messier 047
Orion–Cygnus Arm
? |
https://en.wikipedia.org/wiki/Varna%20Airport | Varna Airport () is the airport of Varna, the historical maritime capital of Bulgaria. Varna Airport is the third largest airport in Bulgaria. It is located 10 kilometers from the center of Varna near the town of Aksakovo. The airport serves Varna, Golden Sands and northeastern Bulgaria. The busiest season for the airport is from the end of May to the beginning of October.
History
The history of the airport dates back to 1916 when two sheds for the first hydro-port in Bulgaria were built in the Peinerdzhik area (present-day Chaika residential area). Irregular mail-plane service from Sofia to Varna was held between 1919 and 1920 and it was not until 1947 that a permanent airline between the two cities was established. What had grown into Tihina Airport was situated west of the present-day Asparuhov bridge and was indeed quite primitive for the demands of a modern city. Thus in 1946 a decision was made and a new airport was constructed several kilometres west of the city, near the village (now town) of Aksakovo, with local people enthusiastically working on the site together with the constructors. Construction and improvement continued throughout the years, with a new terminal built in 1972 and a new runway in 1974.
In 2013, a new passenger terminal opened and the one constructed in the 20th century was closed down.
There are domestic and international flights from Varna to about 70 destinations in 25 countries, with Bulgarian and foreign airlines. The airport is close t |
https://en.wikipedia.org/wiki/Incremental%20compiler | An incremental compiler is a kind of incremental computation applied to the field of compilation. Quite naturally, whereas ordinary compilers make a so-called clean build, that is, (re)build all program modules, an incremental compiler recompiles only modified portions of a program.
Definition
Imperative programming
In imperative programming and software development, incremental compilation takes only the changes of a known set of source files and updates any corresponding output files (in the compiler's target language, often bytecode) that may already exist from previous compilations.
By effectively building upon previously compiled output files, an incremental compiler avoids the wasteful recompiling of entire source files, where most of the code remains unchanged. For most incremental compilers, compiling a program with small changes to its source code is usually near instantaneous.
It can be said that an incremental compiler reduces the granularity of a language's traditional compiling units while maintaining the language's semantics, such that the compiler can append and replace smaller parts.
Many programming tools take advantage of incremental compilers to provide developers with a much more interactive programming environment. It is not unusual that an incremental compiler is invoked for every change of a source file, such that the developer is almost immediately informed about any compilation errors that would arise as a result of their changes to the code. This |
https://en.wikipedia.org/wiki/Braun%27s%20lipoprotein | Braun's lipoprotein (BLP, Lpp, murein lipoprotein, or major outer membrane lipoprotein), found in some gram-negative cell walls, is one of the most abundant membrane proteins; its molecular weight is about 7.2 kDa. It is bound at its C-terminal end (a lysine) by a covalent bond to the peptidoglycan layer (specifically to diaminopimelic acid molecules) and is embedded in the outer membrane by its hydrophobic head (a cysteine with lipids attached). BLP tightly links the two layers and provides structural integrity to the outer membrane.
Characteristics
The gene encoding Braun's lipoprotein initially produces a protein composed of 78 amino acids, which includes a 20 amino acid signal peptide at the amino terminus. The mature protein is 6 kDa in size. Three monomers of Lpp assemble into a leucine zipper coiled-coil trimer.
Large amounts of Braun's lipoprotein is present, more than any other protein in E. coli. Unlike other lipoproteins, it is linked covalently to the peptidoglycan. Lpp connects the outer membrane to the peptidoglycan. Lpp is anchored to the outer membrane by its amino-terminal lipid group. In E. coli, one third of Lpp proteins form a peptide bond via the side chain of its carboxy-terminal lysine with diaminopimelic acid in the peptidoglycan layer. The rest of the Lpp molecules are present in a "free" form unlinked to peptidoglycan. The free form is exposed on the surface of E. coli.
Functions
Lpp, along with another OmpA-like lipoprotein called Pal/Opr |
https://en.wikipedia.org/wiki/Protoplast | Protoplast (), is a biological term coined by Hanstein in 1880 to refer to the entire cell, excluding the cell wall. Protoplasts can be generated by stripping the cell wall from plant, bacterial, or fungal cells by mechanical, chemical or enzymatic means.
Protoplasts differ from spheroplasts in that their cell wall has been completely removed. Spheroplasts retain part of their cell wall. In the case of Gram-negative bacterial spheroplasts, for example, the peptidoglycan component of the cell wall has been removed but the outer membrane component has not.
Enzymes for the preparation of protoplasts
Cell walls are made of a variety of polysaccharides. Protoplasts can be made by degrading cell walls with a mixture of the appropriate polysaccharide-degrading enzymes:
During and subsequent to digestion of the cell wall, the protoplast becomes very sensitive to osmotic stress. This means cell wall digestion and protoplast storage must be done in an isotonic solution to prevent rupture of the plasma membrane.
Uses for protoplasts
Protoplasts can be used to study membrane biology, including the uptake of macromolecules and viruses . These are also used in somaclonal variation.
Protoplasts are widely used for DNA transformation (for making genetically modified organisms), since the cell wall would otherwise block the passage of DNA into the cell. In the case of plant cells, protoplasts may be regenerated into whole plants first by growing into a group of plant cells that dev |
https://en.wikipedia.org/wiki/Subcompact%20car | Subcompact car is a North American classification for cars smaller than a compact car. It is broadly equivalent to the B-segment (Europe), supermini (Great Britain) or A0-class (China) classifications.
According to the U.S. Environmental Protection Agency (EPA) car size class definition, the subcompact category sits between the "minicompact" and "compact" categories. The EPA definition of a subcompact is a passenger car with a combined interior and cargo volume of . Current examples of subcompact cars are the Nissan Versa and Hyundai Accent. The smaller cars in the A-segment/city car category (such as the Chevrolet Spark and Smart Fortwo) are sometimes called subcompacts in the U.S., because the EPA's name for this smaller category — "minicompact" — is not commonly used by the general public.
The prevalence of small cars in the United States increased in the 1960s due to increased imports of cars from Europe and Japan. Widespread use of the term subcompact coincided with the early 1970s increase in subcompact cars built in the United States. Early 1970s subcompacts include the AMC Gremlin, Chevrolet Vega, and Ford Pinto.
History
1960s
The term subcompact originated during the 1960s. However, it came into popular use in the early 1970s, as car manufacturers in the United States began to introduce smaller cars into their line-up. Previously, cars in this size were variously categorized, including "small cars" or "economy cars".
Several of these small cars were produced |
https://en.wikipedia.org/wiki/Rossmann%20fold | The Rossmann fold is a tertiary fold found in proteins that bind nucleotides, such as enzyme cofactors FAD, NAD+, and NADP+. This fold is composed of alternating beta strands and alpha helical segments where the beta strands are hydrogen bonded to each other forming an extended beta sheet and the alpha helices surround both faces of the sheet to produce a three-layered sandwich. The classical Rossmann fold contains six beta strands whereas Rossmann-like folds, sometimes referred to as Rossmannoid folds, contain only five strands. The initial beta-alpha-beta (bab) fold is the most conserved segment of the Rossmann fold. The motif is named after Michael Rossmann who first noticed this structural motif in the enzyme lactate dehydrogenase in 1970 and who later observed that this was a frequently occurring motif in nucleotide binding proteins.
Rossmann and Rossmannoid fold proteins are extremely common. They make up 20% of proteins with known structures in the Protein Data Bank, and are found in more than 38% of KEGG metabolic pathways. The fold is extremely versatile in that it can accommodate a wide range of ligands. They can function as metabolic enzymes, DNA/RNA binding, and regulatory proteins in addition to the traditional role.
History
The Rossmann fold was first described by Dr. Michael Rossmann and coworkers in 1974. He was the first to deduce the structure of lactate dehydrogenase and characterized the structural motif within this enzyme which would later be called th |
https://en.wikipedia.org/wiki/CATH%20database | The CATH Protein Structure Classification database is a free, publicly available online resource that provides information on the evolutionary relationships of protein domains. It was created in the mid-1990s by Professor Christine Orengo and colleagues including Janet Thornton and David Jones, and continues to be developed by the Orengo group at University College London. CATH shares many broad features with the SCOP resource, however there are also many areas in which the detailed classification differs greatly.
Hierarchical organization
Experimentally determined protein three-dimensional structures are obtained from the Protein Data Bank and split into their consecutive polypeptide chains, where applicable. Protein domains are identified within these chains using a mixture of automatic methods and manual curation.
The domains are then classified within the CATH structural hierarchy: at the Class (C) level, domains are assigned according to their secondary structure content, i.e. all alpha, all beta, a mixture of alpha and beta, or little secondary structure; at the Architecture (A) level, information on the secondary structure arrangement in three-dimensional space is used for assignment; at the Topology/fold (T) level, information on how the secondary structure elements are connected and arranged is used; assignments are made to the Homologous superfamily (H) level if there is good evidence that the domains are related by evolution i.e. they are homologous.
Additional |
https://en.wikipedia.org/wiki/George%20Poinar%20Jr. | George O. Poinar Jr. (born April 25, 1936) is an American entomologist and writer. He is known for popularizing the idea of extracting DNA from insects fossilized in amber, an idea which received widespread attention when adapted by Michael Crichton for the book and movie Jurassic Park.
Poinar earned a BS and MS at Cornell University, and remained there for his doctoral studies, receiving a PhD in biology in 1962. He spent many of his years of research at University of California, Berkeley in the Department of Entomology, Division of Insect Pathology. There, and during travels around the globe, he performed research on the axenic culture of nematodes, nematode parasites of insects and the fossil records of insects and nematodes in amber.
In 1992 a team consisting of Poinar, his wife entomologist Roberta Poinar, his son Hendrik, and Dr. Raúl J. Cano of California Polytechnic State University successfully extracted insect DNA from a Lebanese weevil in amber that was 125 million years old, collected by Raif Milki in Lebanon. More recent studies of ancient DNA cast doubt on the DNA results, but not on the authenticity of the amber samples.
In 1995, George and Roberta Poinar, a fellow researcher from Berkeley, moved to Oregon, where they opened the Amber Institute. Upon his move to Oregon he received a courtesy appointment to the Department of Entomology of Oregon State University.
In 2016, Poinar announced the discovery of a new plant species that is a 45-million-year-old re |
https://en.wikipedia.org/wiki/Indecomposability | Indecomposability or indecomposable may refer to any of several subjects in mathematics:
Indecomposable module, in algebra
Indecomposable distribution, in probability
Indecomposable continuum, in topology
Indecomposability (intuitionistic logic), a principle in constructive analysis and in computable analysis
Indecomposability of a polynomial in polynomial decomposition
A property of certain ordinals; see additively indecomposable ordinal |
https://en.wikipedia.org/wiki/Hendrik%20Poinar | Hendrik Nicholas Poinar (born May 31, 1969 in D.C, United States) is an evolutionary biologist specializing in ancient DNA. Poinar first became known for extracting DNA sequences from ground sloth coprolites. He is currently director of the Ancient DNA Centre at McMaster University in Hamilton, Ontario.
Education and academic career
The son of noted entomologist George Poinar Jr. and Eva Hecht-Poinar, Poinar received his B.S. and M.S. degrees from California Polytechnic University, San Luis Obispo in 1992 and 1999 respectively before earning a Ph.D. in 1999 from the Ludwig Maximilian University of Munich, after which he was a postdoctoral researcher from 2000 to 2003 at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. In 2003 he was hired as an assistant professor in the anthropology department at McMaster University in Canada.
In a joint 2000 paper in Science, Poinar and Dr. Alan Cooper argued that much existing work in human ancient DNA has not been sufficiently rigorous to prevent DNA contamination from modern human sources, and that many reported results for ancient human DNA may therefore be suspect.
In 2003, Poinar and others from the Max Planck Institute published genetic sequences isolated from coprolites of the extinct Shasta giant ground sloth, with an estimated age of 10500 years using radiocarbon dates. These were the first genetic sequences retrieved from any extinct ground sloth.
In September 2008, Poinar's laboratory published re |
https://en.wikipedia.org/wiki/International%20Classification%20of%20Functioning%2C%20Disability%20and%20Health | The International Classification of Functioning, Disability and Health (ICF) is a classification of the health components of functioning and disability.
The ICF received approval from all 191 World Health Organization (WHO) member states on May 22, 2001, during the 54th World Health Assembly. Its approval followed nine years of international revision efforts coordinated by WHO. WHO's initial classification for the effects of diseases, the International Classification of Impairments, Disabilities, and Handicaps (ICIDH), was created in 1980.
The ICF classification complements WHO's International Classification of Diseases-10th Revision (ICD), which contains information on diagnosis and health condition, but not on functional status. The ICD and ICF constitute the core classifications in the WHO Family of International Classifications (WHO-FIC).
Overview
The ICF is structured around the following broad components:
Body functions and structure
Activities (related to tasks and actions by an individual) and participation (involvement in a life situation)
Additional information on severity and environmental factors
Functioning and disability are viewed as a complex interaction between the health condition of the individual and the contextual factors of the environment as well as personal factors. The picture produced by this combination of factors and dimensions is of "the person in his or her world". The classification treats these dimensions as interactive and dynamic rath |
https://en.wikipedia.org/wiki/Stochastic%20resonance | Stochastic resonance (SR) is a phenomenon in which a signal that is normally too weak to be detected by a sensor, can be boosted by adding white noise to the signal, which contains a wide spectrum of frequencies. The frequencies in the white noise corresponding to the original signal's frequencies will resonate with each other, amplifying the original signal while not amplifying the rest of the white noise – thereby increasing the signal-to-noise ratio, which makes the original signal more prominent. Further, the added white noise can be enough to be detectable by the sensor, which can then filter it out to effectively detect the original, previously undetectable signal.
This phenomenon of boosting undetectable signals by resonating with added white noise extends to many other systems – whether electromagnetic, physical or biological – and is an active area of research.
Stochastic resonance was first proposed by the Italian physicists Roberto Benzi, Alfonso Sutera and Angelo Vulpiani in 1981, and the first application they proposed (together with Giorgio Parisi) was in the context of climate dynamics.
Technical description
Stochastic resonance (SR) is observed when noise added to a system changes the system's behaviour in some fashion. More technically, SR occurs if the signal-to-noise ratio of a nonlinear system or device increases for moderate values of noise intensity. It often occurs in bistable systems or in systems with a sensory threshold and when the input signal t |
https://en.wikipedia.org/wiki/Marr%E2%80%93Hildreth%20algorithm | In computer vision, the Marr–Hildreth algorithm is a method of detecting edges in digital images, that is, continuous curves where there are strong and rapid variations in image brightness. The Marr–Hildreth edge detection method is simple and operates by convolving the image with the Laplacian of the Gaussian function, or, as a fast approximation by difference of Gaussians. Then, zero crossings are detected in the filtered result to obtain the edges. The Laplacian-of-Gaussian image operator is sometimes also referred to as the Mexican hat wavelet due to its visual shape when turned upside-down. David Marr and Ellen C. Hildreth are two of the inventors.
Limitations
The Marr–Hildreth operator suffers from two main limitations. It generates responses that do not correspond to edges, so-called "false edges", and the localization error may be severe at curved edges. Today, there are much better edge detection methods, such as the Canny edge detector based on the search for local directional maxima in the gradient magnitude, or the differential approach based on the search for zero crossings of the differential expression that corresponds to the second-order derivative in the gradient direction (both of these operations preceded by a Gaussian smoothing step). For more details, see the article on edge detection.
See also
Blob detection
CVIPtools
References
Feature detection (computer vision) |
https://en.wikipedia.org/wiki/Special%20sensor%20microwave/imager | The Special Sensor Microwave/Imager (SSM/I) is a seven-channel, four-frequency, linearly polarized passive microwave radiometer system. It is flown on board the United States Air Force Defense Meteorological Satellite Program (DMSP) Block 5D-2 satellites. The instrument measures surface/atmospheric microwave brightness temperatures (TBs) at 19.35, 22.235, 37.0 and 85.5 GHz. The four frequencies are sampled in both horizontal and vertical polarizations, except the 22 GHz which is sampled in the vertical only.
The SSM/I has been a very successful instrument, superseding the across-track and Dicke radiometer designs of previous systems. Its combination of constant-angle rotary-scanning and total power radiometer design has become standard for passive microwave imagers, e.g. TRMM Microwave Imager, AMSR.
Its predecessor, the Scanning Multichannel Microwave Radiometer (SMMR), provided similar information. Its successor, the Special Sensor Microwave Imager / Sounder (SSMIS), is an enhanced eleven-channel, eight-frequency system.
Products
Along with its predecessor SMMR, the SSM/I contributes to an archive of global passive microwave products from late 1978 to present.
Information within the SSM/I TBs measurements allow the retrieval of four important meteorological parameters over the ocean: near-surface wind speed (note scalar not vector), total columnar water vapor, total columnar cloud liquid water (liquid water path) and precipitation. Accurate and quantitative measureme |
https://en.wikipedia.org/wiki/12A | 12A may refer to:
Media content ratings including the following:
12A issued by the British Board of Film Classification
PG-12, the forerunner to the 12A classification, documented at History of British film certificates
12A issued by the Irish Film Classification Office
12A issued in Malta and Nigeria, documented at Motion picture content rating system
A type of Mazda Wankel engine
Any of the several highways numbered 12A |
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