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https://en.wikipedia.org/wiki/And%20Having%20Writ... | And Having Writ... is a 1978 science fiction/alternate history novel by American writer Donald R. Bensen. Nominated for the 1979 John W. Campbell Award, it tells the story of aliens who crash-land on Earth in 1908 and then journey around the planet, trying to jump-start World War I. Even though they fail to do this, they succeed in creating the circumstances for their ultimate departure from Earth after a period of suspended animation.
Plot summary
According to the novel, the Siberian explosion was originally caused by the crash landing of the spacecraft named The Wanderer. In this alternate reality, however, the alien astronauts are able to commandeer their failing vessel so that it lands in the Pacific Ocean, just outside San Francisco.
Shortly after landing, the quartet of spacemen are rescued from the sea by an American ship and taken to California. The Wanderer sinks into the ocean, and the team reasons that they must find a way to accelerate Earth's technological advances so that they can get back home. The eventual conclusion at which they arrive is that they must provoke the planet into what Ari claims is an inevitable global conflict, one that will (through weaponry innovations) result in a boom of new science and industry.
Characters
The astronauts and their roles
The four astronauts never identify their home world, merely saying that they are a team of Explorers sent to gather information about foreign planets.
Raf: The main character of the book, Raf tells the story in first person. He is a Recorder, and is responsible for ensuring that every detail of the expedition is written down. Raf is quite detached in his observations and seems to be fairly optimistic. While on Earth, he develops a strong taste for alcoholic beverages.
Ari: Ari is a Metahistorian, which seems to signify a study of universal historical trends among people of different galaxies and solar systems. His has a tendency to be very long-winded and often clashes with Dark.
Valmis |
https://en.wikipedia.org/wiki/Nitrate%20reductase%20test | The nitrate reductase test is a test to differentiate between bacteria based on their ability or inability to reduce nitrate (NO3−) to nitrite (NO2−) using anaerobic respiration.
Procedure
Various assays for detecting nitrate reduction have been described. One method is performed as follows:
Inoculate nitrate broth with an isolate and incubate for 48 hours.
Add two nitrate tablets to the sample. If the bacterium produces nitrate reductase, the broth will turn a deep red within 5 minutes at this step.
If no color change is observed, then the result is inconclusive. Add a small amount of zinc to the broth. If the solution remains colorless, then both nitrate reductase and nitrite reductase are present. If the solution turns red, nitrate reductase is not present. |
https://en.wikipedia.org/wiki/10%2C000%2C000 | 10,000,000 (ten million) is the natural number following 9,999,999 and preceding 10,000,001.
In scientific notation, it is written as 107.
In South Asia except for Sri Lanka, it is known as the crore.
In Cyrillic numerals, it is known as the vran (вран — raven).
Selected 8-digit numbers (10,000,001–99,999,999)
10,000,001 to 19,999,999
10,000,019 = smallest 8-digit prime number
10,001,628 = smallest triangular number with 8 digits and the 4,472nd triangular number
10,004,569 = 31632, the smallest 8-digit square
10,077,696 = 2163 = 69, the smallest 8-digit cube
10,172,638 = number of reduced trees with 32 nodes
10,556,001 = 32492 = 574
10,609,137 = Leyland number
10,976,184 = logarithmic number
11,111,111 = repunit
11,316,496 = 33642 = 584
11,390,625 = 33752 = 2253 = 156
11,405,773 = Leonardo prime
11,436,171 = Keith number
11,485,154 = Markov number
11,881,376 = 265
11,943,936 = 34562
12,117,361 = 34812 = 594
12,252,240 = highly composite number, smallest number divisible by all the numbers 1 through 18
12,648,430 = hexadecimal C0FFEE, resembling the word "coffee"; used as a placeholder in computer programming, see hexspeak.
12,890,625 = 1-automorphic number
12,960,000 = 36002 = 604 = (3·4·5)4, Plato's "nuptial number" (Republic VIII; see regular number)
12,988,816 = number of different ways of covering an 8-by-8 square with 32 1-by-2 dominoes
13,079,255 = number of free 16-ominoes
13,782,649 = Markov number
13,845,841 = 37212 = 614
14,348,907 = 2433 = 275 = 315
14,352,282 = Leyland number
14,776,336 = 38442 = 624
14,930,352 = Fibonacci number
15,485,863 = 1,000,000th prime number
15,548,694 = Fine number
15,752,961 = 39692 = 634
15,994,428 = Pell number
16,003,008 = 2523
16,609,837 = Markov number
16,733,779 = number of ways to partition {1,2,...,10} and then partition each cell (block) into subcells.
16,777,216 = 40962 = 2563 = 644 = 166 = 88 = 412 = 224 — hexadecimal "million" (0x1000000), number of possible colors in 24/3 |
https://en.wikipedia.org/wiki/100%2C000%2C000 | 100,000,000 (one hundred million) is the natural number following 99,999,999 and preceding 100,000,001.
In scientific notation, it is written as 108.
East Asian languages treat 100,000,000 as a counting unit, significant as the square of a myriad, also a counting unit. In Chinese, Korean, and Japanese respectively it is yi () (or in ancient texts), eok () and oku (). These languages do not have single words for a thousand to the second, third, fifth powers, etc.
100,000,000 is also the fourth power of 100 and also the square of 10000.
Selected 9-digit numbers (100,000,001–999,999,999)
100,000,001 to 199,999,999
100,000,007 = smallest nine digit prime
100,005,153 = smallest triangular number with 9 digits and the 14,142nd triangular number
100,020,001 = 100012, palindromic square
100,544,625 = 4653, the smallest 9-digit cube
102,030,201 = 101012, palindromic square
102,334,155 = Fibonacci number
102,400,000 = 405
104,060,401 = 102012 = 1014, palindromic square
105,413,504 = 147
107,890,609 = Wedderburn-Etherington number
111,111,111 = repunit, square root of 12345678987654321
111,111,113 = Chen prime, Sophie Germain prime, cousin prime.
113,379,904 = 106482 = 4843 = 226
115,856,201 = 415
119,481,296 = logarithmic number
120,528,657 = number of centered hydrocarbons with 27 carbon atoms
121,242,121 = 110112, palindromic square
123,454,321 = 111112, palindromic square
123,456,789 = smallest zeroless base 10 pandigital number
125,686,521 = 112112, palindromic square
126,390,032 = number of 34-bead necklaces (turning over is allowed) where complements are equivalent
126,491,971 = Leonardo prime
129,140,163 = 317
129,145,076 = Leyland number
129,644,790 = Catalan number
130,150,588 = number of 33-bead binary necklaces with beads of 2 colors where the colors may be swapped but turning over is not allowed
130,691,232 = 425
134,217,728 = 5123 = 89 = 227
134,218,457 = Leyland number
136,048,896 = 116642 = 1084
139,854,276 = 118262, the sma |
https://en.wikipedia.org/wiki/Oxidase%20test | The oxidase test is used to determine whether an organism possesses the cytochrome c oxidase enzyme. The test is used as an aid for the differentiation of Neisseria, Moraxella, Campylobacter and Pasteurella species (oxidase positive). It is also used to differentiate pseudomonads from related species.
Classification
Strains may be either oxidase-positive (OX+) or oxidase-negative (OX-).
OX+
OX+ normally means the bacterium contains cytochrome c oxidase (also known as Complex IV) and can therefore use oxygen for energy production by converting O2 to H2O2 or H2O with an electron transfer chain.
The Pseudomonadaceae are typically OX+.
The Gram-negative diplococci Neisseria and Moraxella are oxidase-positive.
Many Gram-negative, spiral curved rods are also oxidase-positive, which includes Helicobacter pylori, Vibrio cholerae, and Campylobacter jejuni.
Oxidase variable
Legionella pneumophila may be oxidase-positive.
OX−
OX− normally means the bacterium does not contain cytochrome c oxidase and, therefore, either cannot use oxygen for energy production with an electron transfer chain or employs a different cytochrome for transferring electrons to oxygen.
Enterobacteriaceae are typically OX−.
Mechanism
The test uses disks impregnated with a reagent such as N,N,N′,N′-tetramethyl-p-phenylenediamine, TMPD (or N,N-dimethyl-p-phenylenediamine, DMPD, which is also a redox indicator). The reagent is a dark-blue to maroon color when oxidized, and colorless when reduced. Oxidase-positive bacteria possess cytochrome oxidase or indophenol oxidase (an iron-containing hemoprotein). These both catalyze the transport of electrons from donor compounds (NADH) to electron acceptors (usually oxygen). The test reagent TMPD acts as an artificial electron donor for the enzyme oxidase. The oxidized reagent forms the colored compound indophenol blue. The cytochrome system is usually only present in aerobic organisms that are capable of using oxygen as the terminal electron acceptor. Th |
https://en.wikipedia.org/wiki/Circuit%20design | The process of circuit design can cover systems ranging from complex electronic systems down to the individual transistors within an integrated circuit. One person can often do the design process without needing a planned or structured design process for simple circuits. Still, teams of designers following a systematic approach with intelligently guided computer simulation are becoming increasingly common for more complex designs. In integrated circuit design automation, the term "circuit design" often refers to the step of the design cycle which outputs the schematics of the integrated circuit. Typically this is the step between logic design and physical design.
Process
Traditional circuit design usually involves several stages. Sometimes, a design specification is written after liaising with the customer. A technical proposal may be written to meet the requirements of the customer specification. The next stage involves synthesising on paper a schematic circuit diagram, an abstract electrical or electronic circuit that will meet the specifications. A calculation of the component values to meet the operating specifications under specified conditions should be made. Simulations may be performed to verify the correctness of the design.
A breadboard or other prototype version of the design for testing against specification may be built. It may involve making any alterations to the circuit to achieve compliance. A choice as to a method of construction and all the parts and materials to be used must be made. There is a presentation of component and layout information to draughtspersons and layout and mechanical engineers for prototype production. This is followed by the testing or type-testing several prototypes to ensure compliance with customer requirements. Usually, there is a signing and approval of the final manufacturing drawings, and there may be post-design services (obsolescence of components, etc.).
Specification
The process of circuit design begins |
https://en.wikipedia.org/wiki/Evernote | Evernote is a note-taking and task-management application developed by the Evernote Corporation. It is intended for archiving and creating notes with embedded photos, audio, and saved web content. Notes are stored in virtual "notebooks" and can be tagged, annotated, edited, searched, and exported.
Evernote is available on Android, iOS, macOS, Chrome OS (via Web), Microsoft Windows, as well as a web client. It offers free and paid plans for use.
Architecture
Coding and versions
In 2010, the programming language used to write Evernote's software was changed from C# for version 3.5 to C++ in version 4.0 to improve performance.
Data entry
In addition to keyboard input of typed notes, Evernote also supports image capture from cameras on supported devices and voice note recording. In some situations, text that appears in captured images can be recognized using OCR and annotated. Evernote also supports touch and tablet screens with handwriting recognition. Evernote web-clipping plugins are available for most popular Internet browsers and allow marked sections of webpages to be captured and clipped to Evernote. If no section of a webpage has been highlighted, Evernote can clip the full page. Evernote also supports the ability to e-mail notes to the service, allowing for automated note entry via e-mail rules or filters.
Where suitable hardware is available, Evernote can automatically add geolocation tags to notes.
As of November 2018, Evernote Pro integrates directly with Google Drive, Microsoft Outlook, Microsoft Teams, and Slack, and Evernote Pro adds an integration with Salesforce. All versions of Evernote also support integrations through IFTTT and Zapier. In 2013, Evernote deprecated its direct integration with Twitter in favor of these third-party services.
Data storage and access
On supported operating systems, Evernote allows users to store and edit notes on their local machine, using a SQLite database in Windows.
Users with Internet access and an Evernote |
https://en.wikipedia.org/wiki/Algebraic%20semantics%20%28mathematical%20logic%29 | In mathematical logic, algebraic semantics is a formal semantics based on algebras studied as part of algebraic logic. For example, the modal logic S4 is characterized by the class of topological boolean algebras—that is, boolean algebras with an interior operator. Other modal logics are characterized by various other algebras with operators. The class of boolean algebras characterizes classical propositional logic, and the class of Heyting algebras propositional intuitionistic logic. MV-algebras are the algebraic semantics of Łukasiewicz logic.
See also
Algebraic semantics (computer science)
Lindenbaum–Tarski algebra
Further reading
(2nd published by ASL in 2009) open access at Project Euclid
Good introduction for readers with prior exposure to non-classical logics but without much background in order theory and/or universal algebra; the book covers these prerequisites at length. The book, however, has been criticized for poor and sometimes incorrect presentation of abstract algebraic logic results.
Mathematical logic |
https://en.wikipedia.org/wiki/IPOPT | IPOPT, short for "Interior Point OPTimizer, pronounced I-P-Opt", is a software library for large scale nonlinear optimization of continuous systems. It is written in Fortran and C and is released under the EPL (formerly CPL). IPOPT implements a primal-dual interior point method, and uses line searches based on Filter methods (Fletcher and Leyffer). IPOPT can be called from various modeling environments and C.
IPOPT is part of the COIN-OR project.
IPOPT is designed to exploit 1st derivative (gradient) and 2nd derivative (Hessian) information if provided (usually via automatic differentiation routines in modeling environments such as AMPL). If no Hessians are provided, IPOPT will approximate them using a quasi-Newton methods, specifically a BFGS update.
IPOPT was originally developed by Ph.D. student Andreas Wächter and Prof. Lorenz T. Biegler of the Department of Chemical Engineering at Carnegie Mellon University. Their work was recognized with the INFORMS Computing Society Prize in 2009.
Arvind Raghunathan later created an extension to IPOPT for Mathematical programming with equilibrium constraints (MPEC) . This version of IPOPT is generally known as IPOPT-C (with the 'C' standing for 'complementarity'). While in theory any mixed-integer program can be recast as an MPEC, it may or may not be solvable with IPOPT-C. Solution of MINLPs (Mixed-Integer Nonlinear Programs) using IPOPT is still being explored .
Carl Laird and Andreas Wächter are the developers of IPOPT 3.0, which is a re-implementation of IPOPT in C++. Wächter and Laird were awarded the 2011 J. H. Wilkinson Prize for Numerical Software for this development.
See also
AIMMS
AMPL
APMonitor
GAMS
MATLAB |
https://en.wikipedia.org/wiki/Cosmological%20horizon | A cosmological horizon is a measure of the distance from which one could possibly retrieve information. This observable constraint is due to various properties of general relativity, the expanding universe, and the physics of Big Bang cosmology. Cosmological horizons set the size and scale of the observable universe. This article explains a number of these horizons.
Particle horizon
The particle horizon, also called the cosmological horizon, the comoving horizon, or the cosmic light horizon, is the maximum distance from which light from particles could have traveled to the observer in the age of the universe. It represents the boundary between the observable and the unobservable regions of the universe, so its distance at the present epoch defines the size of the observable universe. Due to the expansion of the universe, it is not simply the age of the universe times the speed of light, as in the Hubble horizon, but rather the speed of light multiplied by the conformal time. The existence, properties, and significance of a cosmological horizon depend on the particular cosmological model.
In terms of comoving distance, the particle horizon is equal to the conformal time that has passed since the Big Bang, times the speed of light. In general, the conformal time at a certain time is given in terms of the scale factor by,
or
The particle horizon is the boundary between two regions at a point at a given time: one region defined by events that have already been observed by an observer, and the other by events which cannot be observed at that time. It represents the furthest distance from which we can retrieve information from the past, and so defines the observable universe.
Hubble horizon
Hubble radius, Hubble sphere (not to be confused with a Hubble bubble), Hubble volume, or Hubble horizon is a conceptual horizon defining the boundary between particles that are moving slower and faster than the speed of light relative to an observer at one given time. Note that |
https://en.wikipedia.org/wiki/ZetaGrid | ZetaGrid was at one time the largest distributed computing project, designed to explore the non-trivial roots of the Riemann zeta function, checking over one billion roots a day.
Roots of the zeta function are of particular interest in mathematics; a single root out of alignment would disprove the Riemann hypothesis, with far-reaching consequences for all of mathematics. , no counterexample to the Riemann hypothesis has been found.
The project ended in November 2005 due to instability of the hosting provider. The first more than 1013 zeroes were checked. The project administrator stated that after the results were analyzed, they would be posted on the American Mathematical Society website. The official status remains unclear, however, as it was never published nor independently verified. This is likely because there was no evidence that each zero was actually computed, as there was no process implemented to check each one as it was calculated. |
https://en.wikipedia.org/wiki/Intertrust%20Technologies%20Corporation | Intertrust Technologies Corporation is a software technology company specializing in trusted distributed computing. Intertrust’s product lines consist of a DataOps platform, Application protection and Content protection solutions. Much of Intertrust's digital rights management (DRM) business is based on the Marlin DRM technology, which Intertrust founded along with four consumer electronics companies: Sony, Panasonic, Philips, and Samsung.
Intertrust is headquartered in Silicon Valley and has offices in Tokyo, Seoul, London, Paris, Mumbai, Beijing, Tallinn, Riga and Bangalore.
History
Victor H. Shear received a BA in sociology from Brandeis University, served as chief executive of Data Scientific Corporation from 1982 to 1985, and then co-founded Personal Library Software. Around 1985, Shear attempted to obtain one of the first US patents for software. For example, one patent covered metering and protecting data on a compact disc from 1986.
The company began under the name Electronic Publishing Resources in January 1990. David M. Van Wie became involved with Intertrust in early 1991. Intertrust's technology, called digital rights management (DRM), enabled trusted transactions, from healthcare, enterprise computing to entertainment and consumer electronics. In 1995, the company announced its technology would be used by Novell. Former Bell Labs Fellow David P. Maher became chief technology officer in 1999. In 1996, Electronic Publishing Resources was renamed Intertrust Technologies.
At the peak of the Internet bubble in October 1999, despite a lack of any earnings, Intertrust had its initial public offering. It was listed on the NASDAQ exchange with symbol ITRU. Within six months, the share price rose from $9 to $35, and a secondary offering on April 12, 2000 raised another $92 million.
In 2001, two companies were acquired: PublishOne, Inc., and ZeroGravity Technologies, and Nokia invested $20 million. However, by the end of 2001 losses had climbed to over $115 |
https://en.wikipedia.org/wiki/Allium%20scorodoprasum | The sand leek (Allium scorodoprasum), also known as rocambole and Korean pickled-peel garlic, is a Eurasian species of wild onion with a native range extending across much of Europe, Middle East, and Korea. The species should not be confused with rocambole garlic, which is A. sativum var. ophioscorodon.
Description
The sand leek is a perennial plant with an egg-shaped bulb. The plant produces two to five unstalked leaves, the bases of which are sheath-like. Each leaf blade is linear, 7–20 mm wide, flat with a slight keel, an entire margin and parallel veins. The edges of the leaf and the central vein are rough to the touch. The flowering stem is cylindrical, growing to a height of and the upper half is leafless. The whole plant has an onion-like aroma. The inflorescence is a globular cluster surrounded by membranous bracts in bud which wither when the flowers open. Each individual flower is stalked and has a purple perianth long. There are six tepals, six stamens and a pistil formed from three fused carpels. Mixed with the flowers are a number of purple bulbils. The fruit is a capsule, but the seeds seldom set, and propagation usually takes place when the bulbils are knocked off and grow into new plants.
Distribution and habitat
The natural habitat of A. scorodoprasum is damp broad-leaved woodland, forest margins, shores, hillside meadows and hedgerows. It was at one time used as a kitchen herb and can sometimes be found near old habitations.
Cultivation
A. scorodoprasum is edible but seldom cultivated, and has a shorter flower stalk and fewer and more inconsistently shaped cloves than Rocambole garlic. Sand leek also has a dark violet bulb wrapper.
Elephant garlic (properly A. ampeloprasum var. ampeloprasum) is also sometimes incorrectly sold as A. scorodoprasum. |
https://en.wikipedia.org/wiki/Micrococcal%20nuclease | Micrococcal nuclease (, S7 Nuclease, MNase, spleen endonuclease, thermonuclease, nuclease T, micrococcal endonuclease, nuclease T''', staphylococcal nuclease, spleen phosphodiesterase, Staphylococcus aureus nuclease, Staphylococcus aureus nuclease B, ribonucleate (deoxynucleate) 3'-nucleotidohydrolase) is an endo-exonuclease that preferentially digests single-stranded nucleic acids. The rate of cleavage is 30 times greater at the 5' side of A or T than at G or C and results in the production of mononucleotides and oligonucleotides with terminal 3'-phosphates. The enzyme is also active against double-stranded DNA and RNA and all sequences will be ultimately cleaved.
Characteristics
The enzyme has a molecular weight of 16.9kDa.
The pH optimum is reported as 9.2. The enzyme activity is strictly dependent on Ca2+ and the pH optimum varies according to Ca2+ concentration. The enzyme is therefore easily inactivated by EGTA.
Sources
This enzyme is the extracellular nuclease of Staphylococcus aureus. Two strains, V8 and Foggi, yield almost identical enzymes. A common source is E.coli'' cells carrying a cloned nuc gene encoding Staphylococcus aureus extracellular nuclease (micrococcal nuclease).
Structure
The 3-dimensional structure of micrococcal nuclease (then called Staphyloccal nuclease) was solved very early in the history of protein crystallography, in 1969, deposited as now-obsolete Protein Data Bank file 1SNS. Higher-resolution, more recent crystal structures are available for the apo form as Protein Data Bank file 1SNO: and for the thymidine-diphosphate-inhibited form as Protein Data Bank file 3H6M: or 1SNC: . As seen in the ribbon diagram above, the nuclease molecule has 3 long alpha helices and a 5-stranded, barrel-shaped beta sheet, in an arrangement known as the OB-fold (for oligonucleotide-binding fold) as classified in the SCOP database.
Applications
CUT&RUN sequencing, antibody-targeted controlled cleavage by micrococcal nuclease for transcriptomic p |
https://en.wikipedia.org/wiki/Oppositional%20defiant%20disorder | Oppositional defiant disorder (ODD) is listed in the DSM-5 under Disruptive, impulse-control, and conduct disorders and defined as "a pattern of angry/irritable mood, argumentative/defiant behavior, or vindictiveness". This behavior is usually targeted toward peers, parents, teachers, and other authority figures. Unlike conduct disorder (CD), those with ODD do not show patterns of aggression towards people or animals, destruction of property, theft, or deceit. One half of children with ODD also fulfill the diagnostic criteria for ADHD.
History
Oppositional defiant disorder was first defined in the DSM-III (1980). Since the introduction of ODD as an independent disorder, the field trials to inform its definition have included predominantly male subjects. Some clinicians have debated whether the diagnostic criteria would be clinically relevant for use with women, and furthermore, some have questioned whether gender-specific criteria and thresholds should be included. Additionally, some clinicians have questioned the preclusion of ODD when conduct disorder is present. According to Dickstein, the DSM-5 attempts to:
"redefine ODD by emphasizing a 'persistent pattern of angry and irritable mood along with vindictive behavior,' rather than DSM-IV's focus exclusively on negativistic, hostile, and defiant behavior.' Although DSM-IV implied, but did not mention, irritability, DSM-5 now includes three symptom clusters, one of which is 'angry/irritable mood'—defined as 'loses temper, is touchy/easily annoyed by others, and is angry/resentful.' This suggests that the process of clinically relevant research driving nosology, and vice versa, has ensured that the future will bring greater understanding of ODD."
Epidemiology
ODD is a pattern of negative, defiant, disobedient, and hostile behavior, and it is one of the most prevalent disorders from preschool age to adulthood. This can include frequent temper tantrums, excessive arguing with adults, refusing to follow rules, pu |
https://en.wikipedia.org/wiki/Unifying%20Theories%20of%20Programming | Unifying Theories of Programming (UTP) in computer science deals with program semantics. It shows how denotational semantics, operational semantics and algebraic semantics can be combined in a unified framework for the formal specification, design and implementation of programs and computer systems.
The book of this title by C.A.R. Hoare and He Jifeng was published in the Prentice Hall International Series in Computer Science in 1998 and is now freely available on the web.
Theories
The semantic foundation of the UTP is the first-order predicate calculus, augmented with fixed point constructs from second-order logic. Following the tradition of Eric Hehner, programs are predicates in the UTP, and there is no distinction between programs and specifications at the semantic level. In the words of Hoare:
A computer program is identified with the strongest predicate describing every relevant observation that can be made of the behaviour of a computer executing that program.
In UTP parlance, a theory is a model of a particular programming paradigm. A UTP theory is composed of three ingredients:
an alphabet, which is a set of variable names denoting the attributes of the paradigm that can be observed by an external entity;
a signature, which is the set of programming language constructs intrinsic to the paradigm; and
a collection of healthiness conditions, which define the space of programs that fit within the paradigm. These healthiness conditions are typically expressed as monotonic idempotent predicate transformers.
Program refinement is an important concept in the UTP. A program is refined by if and only if every observation that can be made of is also an observation of .
The definition of refinement is common across UTP theories:
where denotes the universal closure of all variables in the alphabet.
Relations
The most basic UTP theory is the alphabetised predicate calculus, which has no alphabet restrictions or healthiness conditions. The theory of relatio |
https://en.wikipedia.org/wiki/Flavoprotein | Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin. These proteins are involved in a wide array of biological processes, including removal of radicals contributing to oxidative stress, photosynthesis, and DNA repair. The flavoproteins are some of the most-studied families of enzymes.
Flavoproteins have either FMN (flavin mononucleotide) or FAD (flavin adenine dinucleotide) as a prosthetic group or as a cofactor. The flavin is generally tightly bound (as in adrenodoxin reductase, wherein the FAD is buried deeply). About 5-10% of flavoproteins have a covalently linked FAD. Based on the available structural data, FAD-binding sites can be divided into more than 200 different types.
90 flavoproteins are encoded in the human genome; about 84% require FAD and around 16% require FMN, whereas 5 proteins require both. Flavoproteins are mainly located in the mitochondria. Of all flavoproteins, 90% perform redox reactions and the other 10% are transferases, lyases, isomerases, ligases.
Discovery
Flavoproteins were first mentioned in 1879, when they isolated as a bright-yellow pigment from cow's milk. They were initially termed lactochrome. By the early 1930s, this same pigment had been isolated from a range of sources, and recognised as a component of the vitamin B complex. Its structure was determined and reported in 1935 and given the name riboflavin, derived from the ribityl side chain and yellow colour of the conjugated ring system.
The first evidence for the requirement of flavin as an enzyme cofactor came in 1935. Hugo Theorell and coworkers showed that a bright-yellow-coloured yeast protein, identified previously as essential for cellular respiration, could be separated into apoprotein and a bright-yellow pigment. Neither apoprotein nor pigment alone could catalyse the oxidation of NADH, but mixing of the two restored the enzyme activity. However, replacing the isolated pigment with riboflavin did not restore enzyme activity, despite bein |
https://en.wikipedia.org/wiki/He%20Jifeng | He Jifeng (, born August 1943) is a Chinese computer scientist.
He Jifeng graduated from the mathematics department of Fudan University in 1965. From 1965 to 1985, he was an instructor at East China Normal University. During 1980–81, he was a visiting scholar at Stanford University and the University of San Francisco in California, United States.
From 1984 to 1998, He Jifeng was a senior research fellow at the Programming Research Group in the Oxford University Computing Laboratory (now the Oxford University Department of Computer Science). He worked extensively on formal aspects of computing science. In particular, he worked with Prof. Sir Tony Hoare, latterly on Unifying Theories of Programming, resulting in a book of that name.
Since 1986, He Jifeng has been Professor of Computer Science at East China Normal University in Shanghai. In 1996, he also became Professor of Computer Science at Shanghai Jiao Tong University.
In 1998, he became a senior research fellow at the International Institute for Software Technology (UNU-IIST), United Nations University, based in Macau. He moved back to Shanghai in 2005.
He Jifeng's research interests include sound methods for the specification of computer systems, communications, applications, standards, and techniques for designing and implementing those specifications in software and/or hardware with high reliability.
In 2005, he was elected to the Chinese Academy of Sciences. In 2013, his 70th birthday was celebrated at East China Normal University with an international three-day Festschrift in association with the International Conference on Theoretical Aspects of Computing (ICTAC). Ten years later in 2023, his 80th birthday was celebrated at the Shanghai Science Hall with a hybrid international two-day Festschrift Symposium. Since 2019, he has been a Distinguished Professor at Tongji University in Shanghai.
Books
He Jifeng has written a number of computer science books, including:
He Jifeng, Provably Correct System |
https://en.wikipedia.org/wiki/Sessile%20drop%20technique | In materials science, the sessile drop technique is a method used for the characterization of solid surface energies, and in some cases, aspects of liquid surface energies. The main premise of the method is that by placing a droplet of liquid with a known surface energy and contact angle, the surface energy of the solid substrate can be calculated. The liquid used for such experiments is referred to as the probe liquid, and the use of several different probe liquids is required.
Probe liquid
The surface energy is measured in units of joules per square meter, which is equivalent in the case of liquids to surface tension, measured in newtons per meter. The overall surface tension/energy of a liquid can be acquired through various methods using a tensiometer or using the pendant drop method and maximum bubble pressure method.
The interface tension at the interface of the probe liquid and the solid surface can additionally be viewed as being the result of different types of intermolecular forces. As such, surface energies can be subdivided according to the various interactions that cause them, such as the surface energy due to dispersive (e.g. van der Waals forces) and other interactions (e.g. hydrogen bonding, polar interactions, acid–base interactions, etc.). It is often useful for the sessile drop technique to use liquids that are known to be incapable of some of those interactions (see table 1). For example, the surface tension of all straight alkanes is said to be entirely dispersive, and all of the other components are zero. This is algebraically useful, as it eliminates a variable in certain cases and makes these liquids essential testing materials.
The overall surface energy, both for a solid and a liquid, is assumed traditionally to simply be the sum of the components considered. For example, the equation describing the subdivision of surface energy into the contributions of dispersive interactions and polar interactions would be
where σS is the total |
https://en.wikipedia.org/wiki/A549%20cell | A549 cells are adenocarcinomic human alveolar basal epithelial cells, and constitute a cell line that was first developed in 1972 by D. J. Giard, et al. through the removal and culturing of cancerous lung tissue in the explanted tumor of a 58-year-old caucasian male. The cells are used as models for the study of lung cancer and the development of drug therapies against it.
Characteristics
A549 cells, as found in the lung tissue of their origin, are squamous and responsible for the diffusion of some substances, such as water and electrolytes, across alveoli. If A549 cells are cultured in vitro, they grow as a monolayer; adherent or attaching to the culture flask. The cells are able to synthesize lecithin and contain high levels of unsaturated fatty acids, which are important to maintain membrane phospholipids. A549 cells are widely used as a type II pulmonary epithelial cell model for drug metabolism and as a transfection host. When grown for a sufficiently long time in cell culture, A549 cells may begin to differentiate, as signaled by the presence of multilamellar bodies.
Usage
A549 cells have served as models of alveolar Type II pulmonary epithelium, finding utility in research examining the metabolic processing of lung tissue and possible mechanisms of drug delivery to the tissue. In context of lung cancer drug development, the cells have served as testing grounds for novel drugs - such as paclitaxel, docetaxel, and bevacizumab - both in vitro and in vivo through cell culture and xenografting, respectively. Single-cell tracking of A549 has enabled the elaboration of pedigree-tree profiles and demonstrate correlations in behavior among sister cells and their descendants. Such observations of correlations can be used as proxy measurements to identify cellular stress and inheritance as a response to drug treatment. A549 has also been employed in viral research and associated protein expression changes as a consequence of viral infection. Although A549 is a cance |
https://en.wikipedia.org/wiki/Facing%20Identification%20Mark | The Facing Identification Mark, or FIM, is a bar code designed by the United States Postal Service to assist in the automated processing of mail. The FIM is a set of vertical bars printed on the envelope or postcard near the upper edge, just to the left of the postage area (the area where the postage stamp or its equivalent is placed). The FIM is intended for use primarily on preprinted envelopes and postcards and is applied by the company printing the envelopes or postcards, not by the USPS.
The FIM is a nine-bit code consisting of ones (vertical bars) and zeroes (blank spaces). The following five codes are in use:
FIM A: || | || (110010011)
FIM B: | || || | (101101101)
FIM C: || | | || (110101011)
FIM D: ||| | ||| (111010111)
FIM E: | | | | (101000101)
All defined FIMs start and end with a bar, and are palindromic, reading the same forward and backward. Thus, there are only 16 possible FIMs, 11 if the current limits of at most 3 consecutive bars or spaces are maintained.
The FIM allows the proper facing of mail for cancellation. It also identifies the manner in which postage is paid (e.g., business reply mail or Information Based Indicia (IBI) postage) and whether that business reply mail has a barcode, typically an Intelligent Mail Barcode or the older POSTNET barcode. If the barcode is present, the mail can be sent directly to a sorter.
The five codes have the following uses:
FIM A is used for mail bearing regular postage and an Intelligent Mail Barcode. It is commonly used by preprinted courtesy reply mail and metered reply mail, but may be applied to any mail to speed delivery.
FIM B is used for business reply mail without a preprinted barcode. Because this costs more than barcoded mail, it is rarely used.
FIM C is used for business reply mail with a preprinted Intelligent Mail Barcode.
FIM D is used only with IBI postage.
FIM E is used to mark Share Mail, where the Intelligent Mail Barcode is used as postage. |
https://en.wikipedia.org/wiki/Preputial%20gland | Preputial glands are exocrine glands that are located in the folds of skin front of the genitals of some mammals. They occur in several species, including mice, ferrets, rhinoceroses, and even-toed ungulates and produce pheromones. The glands play a role in the urine-marking behavior of canids such as gray wolves and African wild dogs. The preputial glands of female animals are sometimes called clitoral glands.
The preputial glands of male musk deer produce strong-smelling deer musk which is of economic importance, as it is used in perfumes.
Human homologues
There is debate about whether humans have functional homologues to preputial glands. Preputial glands were first noted by Edward Tyson and in 1694 fully described by William Cowper who named them Tyson's glands after Tyson. They are described as modified sebaceous glands located around the corona and inner surface of the prepuce of the human penis. They are believed to be most frequently found in the balanopreputial sulcus. Their secretion may be one of the components of smegma.
Some, including Satya Parkash, dispute their existence. While humans may not have true anatomical equivalents, the term may sometimes be used for tiny whitish yellow bumps occasionally found on the corona of the glans penis. The proper name for these structures is pearly penile papules (or hirsutoid papillomas). According to detractors, they are not glands, but mere thickenings of the skin and are not involved in the formation of smegma.
See also
List of specialized glands within the human integumentary system |
https://en.wikipedia.org/wiki/Quantum%20flux%20parametron | A Quantum Flux Parametron (QFP) is a digital logic implementation technology based on superconducting Josephson junctions. QFP's were invented by Eiichi Goto at the University of Tokyo as an improvement over his earlier parametron based digital logic technology, which did not use superconductivity effects or Josephson junctions. The Josephson junctions on QFP integrated circuits to improve speed and energy efficiency enormously over the parametrons.
In some applications, the complexity of the cryogenic cooling system required is negligible compared to the potential speed gains. While his design makes use of quantum principles, it is not a quantum computer technology, gaining speed only through higher clock speeds.
Apart from the speed advantage over traditional CMOS integrated circuit design is that parametrons can be operated with zero energy loss (no local increase in entropy), making reversible computing possible. Low energy use and heat generation is critical in supercomputer design, where thermal load per unit volume has become one of the main limiting factors.
A related technology is the Rapid Single Flux Quantum digital logic. |
https://en.wikipedia.org/wiki/List%20of%20uniform%20polyhedra | In geometry, a uniform polyhedron is a polyhedron which has regular polygons as faces and is vertex-transitive (transitive on its vertices, isogonal, i.e. there is an isometry mapping any vertex onto any other). It follows that all vertices are congruent, and the polyhedron has a high degree of reflectional and rotational symmetry.
Uniform polyhedra can be divided between convex forms with convex regular polygon faces and star forms. Star forms have either regular star polygon faces or vertex figures or both.
This list includes these:
all 75 nonprismatic uniform polyhedra;
a few representatives of the infinite sets of prisms and antiprisms;
one degenerate polyhedron, Skilling's figure with overlapping edges.
It was proven in that there are only 75 uniform polyhedra other than the infinite families of prisms and antiprisms. John Skilling discovered an overlooked degenerate example, by relaxing the condition that only two faces may meet at an edge. This is a degenerate uniform polyhedron rather than a uniform polyhedron, because some pairs of edges coincide.
Not included are:
The uniform polyhedron compounds.
40 potential uniform polyhedra with degenerate vertex figures which have overlapping edges (not counted by Coxeter);
The uniform tilings (infinite polyhedra)
11 Euclidean convex uniform tilings;
28 Euclidean nonconvex or apeirogonal uniform tilings;
Infinite number of uniform tilings in hyperbolic plane.
Any polygons or 4-polytopes
Indexing
Four numbering schemes for the uniform polyhedra are in common use, distinguished by letters:
[C] Coxeter et al., 1954, showed the convex forms as figures 15 through 32; three prismatic forms, figures 33–35; and the nonconvex forms, figures 36–92.
[W] Wenninger, 1974, has 119 figures: 1–5 for the Platonic solids, 6–18 for the Archimedean solids, 19–66 for stellated forms including the 4 regular nonconvex polyhedra, and ended with 67–119 for the nonconvex uniform polyhedra.
[K] Kaleido, 1993: The 80 figure |
https://en.wikipedia.org/wiki/Busemann%20function | In geometric topology, Busemann functions are used to study the large-scale geometry of geodesics in Hadamard spaces and in particular Hadamard manifolds (simply connected complete Riemannian manifolds of nonpositive curvature). They are named after Herbert Busemann, who introduced them; he gave an extensive treatment of the topic in his 1955 book "The geometry of geodesics".
Definition and elementary properties
Let be a metric space. A geodesic ray is a path which minimizes distance everywhere along its length. i.e., for all ,
Equivalently, a ray is an isometry from the "canonical ray" (the set equipped with the Euclidean metric) into the metric space X.
Given a ray γ, the Busemann function is defined by
Thus, when t is very large, the distance is approximately equal to . Given a ray γ, its Busemann function is always well-defined: indeed the right hand side above , tends pointwise to the left hand side on compacta, since is bounded above by and non-increasing since, if ,
It is immediate from the triangle inequality that
so that is uniformly continuous. More specifically, the above estimate above shows that
Busemann functions are Lipschitz functions with constant 1.
By Dini's theorem, the functions tend to uniformly on compact sets as t tends to infinity.
Example: Poincaré disk
Let be the unit disk in the complex plane with the Poincaré metric
Then, for and , the Busemann function is given by
where the term in brackets on the right hand side is the Poisson kernel for the unit disk and corresponds to the radial geodesic from the origin towards ,
. The computation of can be reduced to that of , since the metric is invariant under Möbius transformations in ; the geodesics through have the form where is the 1-parameter subgroup of ,
The formula above also completely determines the Busemann function by Möbius invariance.
Busemann functions on a Hadamard space
In a Hadamard space, where any two points are joined by a unique geodesic |
https://en.wikipedia.org/wiki/Hadamard%20space | In geometry, an Hadamard space, named after Jacques Hadamard, is a non-linear generalization of a Hilbert space. In the literature they are also equivalently defined as complete CAT(0) spaces.
A Hadamard space is defined to be a nonempty complete metric space such that, given any points and there exists a point such that for every point
The point is then the midpoint of and
In a Hilbert space, the above inequality is equality (with ), and in general an Hadamard space is said to be if the above inequality is equality. A flat Hadamard space is isomorphic to a closed convex subset of a Hilbert space. In particular, a normed space is an Hadamard space if and only if it is a Hilbert space.
The geometry of Hadamard spaces resembles that of Hilbert spaces, making it a natural setting for the study of rigidity theorems. In a Hadamard space, any two points can be joined by a unique geodesic between them; in particular, it is contractible. Quite generally, if is a bounded subset of a metric space, then the center of the closed ball of the minimum radius containing it is called the circumcenter of Every bounded subset of a Hadamard space is contained in the smallest closed ball (which is the same as the closure of its convex hull). If is the group of isometries of a Hadamard space leaving invariant then fixes the circumcenter of (Bruhat–Tits fixed point theorem).
The basic result for a non-positively curved manifold is the Cartan–Hadamard theorem. The analog holds for a Hadamard space: a complete, connected metric space which is locally isometric to a Hadamard space has an Hadamard space as its universal cover. Its variant applies for non-positively curved orbifolds. (cf. Lurie.)
Examples of Hadamard spaces are Hilbert spaces, the Poincaré disc, complete real trees (for example, complete Bruhat–Tits building), -space with and and Hadamard manifolds, that is, complete simply-connected Riemannian manifolds of nonpositive sectional curvature. Important exa |
https://en.wikipedia.org/wiki/Biceps%20femoris%20muscle | The biceps femoris () is a muscle of the thigh located to the posterior, or back. As its name implies, it consists of two heads; the long head is considered part of the hamstring muscle group, while the short head is sometimes excluded from this characterization, as it only causes knee flexion (but not hip extension) and is activated by a separate nerve (the peroneal, as opposed to the tibial branch of the sciatic nerve).
Structure
It has two heads of origin:
the long head arises from the lower and inner impression on the posterior part of the tuberosity of the ischium. This is a common tendon origin with the semitendinosus muscle, and from the lower part of the sacrotuberous ligament.
the short head, arises from the lateral lip of the linea aspera, between the adductor magnus and vastus lateralis extending up almost as high as the insertion of the gluteus maximus, from the lateral prolongation of the linea aspera to within 5 cm. of the lateral condyle; and from the lateral intermuscular septum.
The two muscle heads joint together distally and unite in an intricate fashion. The fibers of the long head form a fusiform belly, which passes obliquely downward and lateralward across the sciatic nerve to end in an aponeurosis which covers the posterior surface of the muscle and receives the fibers of the short head. Inferiorly, the aponeurosis condenses to form a tendon which predominantly inserts onto the lateral side of the head of the fibula. There is a second small insertional attachment by a small tendon slip into the lateral condyle of the tibia.
At its insertion the tendon divides into two portions, which embrace the fibular collateral ligament of the knee-joint. Together, this joining of tendons is commonly referred to as the conjoined tendon of the knee.
From the posterior border of the tendon a thin expansion is given off to the fascia of the leg. The tendon of insertion of this muscle forms the lateral hamstring; the common fibular (peroneal) nerve descen |
https://en.wikipedia.org/wiki/Application%20domain | An application domain is a mechanism (similar to a process in an operating system) used within the Common Language Infrastructure (CLI) to isolate executed software applications from one another so that they do not affect each other. Each application domain has its own virtual address space which scopes the resources for the application domain using that address space.
Creating multiple application domains in the same process is not possible in .NET Core and .NET 5+.
Properties
A CLI application domain is contained within an operating system process. A process may contain many application domains. Application domains have isolation properties similar to that of operating system processes:
Multiple threads can exist within a single application domain.
An application within a domain can be stopped without affecting the state of another domain in the same process.
A fault or exception in one domain does not affect an application in another domain or crash the entire process that hosts the domains.
Configuration information is part of a domain's scope, not the scope of the process.
Each domain can be assigned different security access levels.
Code in one domain cannot directly access code in another.
In this sense, a CLI is like a mini-operating system. It runs a single process that contains a number of sub-processes, or application domains.
The advantage of application domains is that running multiple application domains may require fewer resources, such as memory, than running multiple operating system processes. Communication between domains still requires marshalling, so the overheads can be closer to using multiple processes than to communicating within a single domain.
Inter-domain communications
Direct communication cannot be achieved across application domains. However, application domains can still talk to each other by passing objects via marshalling by value (unbound objects), marshalling by reference through a proxy (application-domain-bound objec |
https://en.wikipedia.org/wiki/Hypertime | Hypertime is a fictional concept in DC Comics which first appeared in the 1999 The Kingdom limited series. It is a variation of the Multiverse concept that existed in DC Comics before 1985's Crisis on Infinite Earths limited series and was created by Mark Waid and Grant Morrison.
Hypertime, described in The Kingdom #2 as "the vast interconnected web of parallel time-lines which comprise all reality", was an attempt by Waid to resolve the various tangled continuity issues that were supposed to have been solved by Crisis on Infinite Earths. Keith Dallas and Jason Sacks wrote: "Through Hypertime, Waid sought to resolve the contradictions in DC's continuity once and for all. Indeed, Hypertime allows for contradictions because anything that didn't make sense can be attributed to overlapping timelines".
Concept
The Kingdom
Hypertime is a network of alternate timelines that branch off from the DC Universe. These timelines sometimes overlap with each other, causing alterations in reality. Characters can cross from one timeline to another if needed. It has been analogized to a river network that branches out and then runs 'up stream' to feed back into itself before splitting off again.
Hypertime has been used as a device to explain continuity errors. Some fans welcomed the idea as an explanation for earlier continuity errors while others criticized it for being a license to create more narrative problems.
The Hypertime concept was first introduced in The Kingdom, Mark Waid's sequel to Kingdom Come, and exists within the larger multiverse used within DC Comics publications.
Writer Mark Waid stated that "the possibilities are endless. Hypertime is an unashamed reaction to nearly 15 years of comics being made 'more realistic', less 'larger than life'. As far as we’re concerned, DC Comics shouldn't be about rules and regulations and ‘can’t happen’s and ‘shouldn’t be’s; they should be about anything and everything that tells a good story and gets fans excited".
Infinite Cr |
https://en.wikipedia.org/wiki/Serengeti%20cat | The Serengeti is a hybrid breed of domestic cat, first developed by crossing a Bengal (domestic and wild hybrid) and an Oriental Shorthair. Created by biologist Karen Sausman of Kingsmark Cattery in California in 1994, the breed is still in the development stages, but the ultimate aim is to produce a cat that looks similar to a serval, without using any recent wild cat blood.
Serengetis are spotted cats, with long legs and very large, round tipped ears. They have a long neck which blends with the base of the skull without tapering. Males are generally slightly larger and heavier than females and can weigh between ; females generally weigh between . They are recognized by TICA in tabby, ebony silver, ebony smoke and solid black.
Recognized and registered by The International Cat Association (TICA), no other first generation crosses can be registered as Serengeti. From the Bengal × Oriental cross came the first foundation Serengeti. Breeders then worked with the cat to produce a cat that resembles the breed profile set by TICA.
(Bengal cats originate from hybridization of leopard cats and domestic cats. Most Bengal cats used in Serengeti breeding programs are many generations removed from these origins and possess few genetic contributions of the wild forebears except alleles affecting coat color.)
The tabby is known as the brown-spotted in the UK. However spots can be black or dark brown on a tan, light beige or gold background. The silver has black spots on a silver background. Ghost spotting can sometimes be seen on the solid black version.
See also
Chausie, a breed of cat hybridized with jungle cat
Savannah, a breed which integrates the serval's genes |
https://en.wikipedia.org/wiki/Proteose | A proteose is any of various water-soluble compounds that are produced during in-vitro or in-vivo hydrolytic breakdown of proteins a little before producing amino acids. It forms after breaking down of polypeptides by proteases such as gastric pepsin. In addition to proteoses, peptones are also formed at this stage. The difference between peptones and proteoses is that proteoses are precipitated from solution by half saturation with ammonium sulfate, while peptones don't react even with fully saturated ammonium sulfate.
The proenzyme Pepsinogen, with the exposure to hydrochloric acid gets converted into the active enzyme pepsin, the proteolytic enzyme of the stomach. Hydrochloric acid (HCl) provides the acidic pH (pH 1.8) optimal for pepsins.
Rennin is a proteolytic enzyme found in gastric juice of infants which helps in the digestion of milk proteins. |
https://en.wikipedia.org/wiki/Clonal%20selection | In immunology, clonal selection theory explains the functions of cells of the immune system (lymphocytes) in response to specific antigens invading the body. The concept was introduced by Australian doctor Frank Macfarlane Burnet in 1957, in an attempt to explain the great diversity of antibodies formed during initiation of the immune response. The theory has become the widely accepted model for how the human immune system responds to infection and how certain types of B and T lymphocytes are selected for destruction of specific antigens.
The theory states that in a pre-existing group of lymphocytes (both B and T cells
), a specific antigen activates (i.e. selects) only its counter-specific cell, which then induces that particular cell to multiply, producing identical clones for antibody production. This activation occurs in secondary lymphoid organs such as the spleen and the lymph nodes. In short, the theory is an explanation of the mechanism for the generation of diversity of antibody specificity. The first experimental evidence came in 1958, when Gustav Nossal and Joshua Lederberg showed that one B cell always produces only one antibody. The idea turned out to be the foundation of molecular immunology, especially in adaptive immunity.
Postulates
The clonal selection theory can be summarised with the following four tenets:
Each lymphocyte bears a single type of receptor with a unique specificity (generated by V(D)J recombination).
Receptor occupation is required for cell activation.
The differentiated effector cells derived from an activated lymphocyte bear receptors of identical specificity as the parent cell.
Those lymphocytes bearing receptors for self molecules (i.e., endogenous antigens produced within the body) are destroyed at an early stage.
Early work
In 1900, Paul Ehrlich proposed the so-called "side chain theory" of antibody production. According to it, certain cells exhibit on their surface different "side chains" (i.e. membrane-bound antibodie |
https://en.wikipedia.org/wiki/List%20of%20U.S.%20state%20foods | This is a list of official U.S. state foods:
Notes
See also
List of U.S. state beverages |
https://en.wikipedia.org/wiki/Five-dimensional%20space | A five-dimensional space is a space with five dimensions. In mathematics, a sequence of N numbers can represent a location in an N-dimensional space. If interpreted physically, that is one more than the usual three spatial dimensions and the fourth dimension of time used in relativistic physics. Whether or not the universe is five-dimensional is a topic of debate.
Physics
Much of the early work on five-dimensional space was in an attempt to develop a theory that unifies the four fundamental interactions in nature: strong and weak nuclear forces, gravity and electromagnetism. German mathematician Theodor Kaluza and Swedish physicist Oskar Klein independently developed the Kaluza–Klein theory in 1921, which used the fifth dimension to unify gravity with electromagnetic force. Although their approaches were later found to be at least partially inaccurate, the concept provided a basis for further research over the past century.
To explain why this dimension would not be directly observable, Klein suggested that the fifth dimension would be rolled up into a tiny, compact loop on the order of 10 centimeters. Under his reasoning, he envisioned light as a disturbance caused by rippling in the higher dimension just beyond human perception, similar to how fish in a pond can only see shadows of ripples across the surface of the water caused by raindrops. While not detectable, it would indirectly imply a connection between seemingly unrelated forces. The KaluzaKlein theory experienced a revival in the 1970s due to the emergence of superstring theory and supergravity: the concept that reality is composed of vibrating strands of energy, a postulate only mathematically viable in ten dimensions or more. Superstring theory then evolved into a more generalized approach known as M-theory. M-theory suggested a potentially observable extra dimension in addition to the ten essential dimensions which would allow for the existence of superstrings. The other 10 dimensions are compacted, o |
https://en.wikipedia.org/wiki/Microsoft%20Assistance%20Markup%20Language | Microsoft Assistance Markup Language (Microsoft AML, generally referred to as MAML) is an XML-based markup language developed by the Microsoft User Assistance Platform team to provide user assistance ("online help") for the Microsoft Windows Vista operating system. It makes up the Assistance Platform on Windows Vista.
MAML is also used to provide help information for PowerShell V2 Cmdlets, modules and advanced functions.
Concept
MAML is a departure from all previous types of user assistance for Windows operating systems. Some of its features have been available in .NET Framework 2, but more options shipped with the release of .NET Framework 3. Previously, user assistance for Windows operating systems used Microsoft Compiled HTML Help files, which contains little machine-readable semantic information.
The most significant aspect of MAML is that it shifts the production of user assistance to the concept of structured authoring (somewhat similar to DITA or DocBook). Documents and their constituent elements are defined by their context. With MAML, the emphasis is on content and the tasks a user performs with a computer, not the features of the software. Presentation is managed as part of the rendering engine when a user requests a topic.
The structured feature of MAML means that it can express a wide range of active concepts as well. One notable feature is guided help (active content wizard), which allows the help file to either run a task automatically or highlight the parts of the screen a user should interact with step-by-step. This feature was considered a highlight of Project Longhorn, but Microsoft decided against including it in the final Vista release.
The MAML authoring structure is divided into segments related to a type of content: conceptual, FAQ, glossary, procedure, reference, reusable content, task, troubleshooting, and tutorial.
Presentation
Three levels of transformation occur when a topic is displayed: structure, presentation, and rendering:
|
https://en.wikipedia.org/wiki/Purple%20fringing | In photography (particularly digital photography), purple fringing (sometimes called PF) is the term for an unfocused purple or magenta "ghost" image on a photograph. This optical aberration is generally most visible as a coloring and lightening of dark edges adjacent to bright areas of broad-spectrum illumination, such as daylight or various types of gas-discharge lamps.
Lenses in general exhibit axial chromatic aberration, in which different colors of light do not focus in the same plane. Normally, lens designs are optimized so that two or more (at least three for apochromatic lenses) wavelengths of light in the visible spectrum focus at the same plane. Wavelengths very different from those optimized in the design process may be severely out of focus while the reference colors are in focus; this axial chromatic aberration is usually severe at short wavelengths (violet). Lens performance may be poor for such wavelengths in other ways too, including an increase in flare due to anti-reflective coatings also being optimized for the expected wavelengths.
Most film has relatively low sensitivity to colors outside the visible range, so light spread in the near ultraviolet (UV) or near infrared (IR) rarely has a significant impact on the image recorded. However, image sensors used in digital cameras commonly are sensitive to a wider range of wavelengths . Although the lens glass itself filters out much of the UV light, and all digital cameras designed for color photography incorporate filters to reduce red and IR sensitivity , the chromatic aberration can be sufficient for unfocused violet light to tint nearby dark regions of the image . Bright cloudy or hazy skies are strong sources of scattered violet and UV light , so they tend to cause the problem.
The term purple fringe used to describe one aspect of chromatic aberration dates back to at least 1833.
However, Brewster's description with a purple fringe on one edge and a green fringe on the other is a lateral chroma |
https://en.wikipedia.org/wiki/Allophycocyanin | Allophycocyanin ("other algal blue protein"; from Greek: (allos) meaning "other", (phykos) meaning “alga”, and (kyanos) meaning "blue") is a protein from the light-harvesting phycobiliprotein family, along with phycocyanin, phycoerythrin and phycoerythrocyanin. It is an accessory pigment to chlorophyll. All phycobiliproteins are water-soluble and therefore cannot exist within the membrane like carotenoids, but aggregate, forming clusters that adhere to the membrane called phycobilisomes. Allophycocyanin absorbs and emits red light (650 & 660 nm max, respectively), and is readily found in Cyanobacteria (also called blue-green algae), and red algae. Phycobilin pigments have fluorescent properties that are used in immunoassay kits. In flow cytometry, it is often abbreviated APC. To be effectively used in applications such as FACS, High-Throughput Screening (HTS) and microscopy, APC needs to be chemically cross-linked.
Structural characteristics
Allophycocyanin can be isolated from various species of red or blue-green algae, each producing slightly different forms of the molecule. It is composed of two different subunits (α and β) in which each subunit has one phycocyanobilin (PCB) chromophore. The subunit structure for APC has been determined as (αβ)3. The molecular weight of APC is 105,000 Daltons.
Spectral characteristics
Cross-linked APC
As mentioned above, in order for APC to be useful in immunoassays it must first be chemically cross-linked to prevent it from dissociating into its component subunits when in common physiological buffers. The conventional method for accomplishing this is through a destructive process wherein the treated APC trimer is chemically disrupted in 8M urea and then allowed to re-associate through in a physiological buffer. An alternative method can be used which preserves the structural integrity of the APC trimer and allows for a brighter, more stable end-product.
Applications
Many applications and instruments were developed spec |
https://en.wikipedia.org/wiki/Pseudolocalization | Pseudolocalization (or pseudo-localization) is a software testing method used for testing internationalization aspects of software. Instead of translating the text of the software into a foreign language, as in the process of localization, the textual elements of an application are replaced with an altered version of the original language. For example, instead of "Account Settings", the text may be altered to display as "!!! Àççôûñţ Šéţţîñĝš !!!".
These specific alterations make the original words appear readable, but include the most problematic characteristics of the world's languages: varying length of text or characters, language direction, fit into the interface and so on.
Localization process
Traditionally, localization of software is independent of the software development process. In a typical scenario, software would be built and tested in one base language (such as English), with any localizable elements being extracted into external resources. Those resources are handed off to a localization team for translation into different target languages. The problem with this approach is that many subtle software bugs may be found during the process of localization, when it is too late (or more likely, too expensive) to fix them.
The types of problems that can arise during localization involve differences in how written text appears in different languages. These problems include:
Translated text that is significantly longer than the source language, and does not fit within the UI constraints, or which causes text breaks at awkward positions.
Font glyphs that are significantly larger than, or possess diacritic marks not found in, the source language, and which may be cut off vertically.
Languages for which the reading order is not left-to-right, which is especially problematic for user input.
Application code that assumes all characters fit into a limited character set, such as ASCII or ANSI, which can produce actual logic bugs if left uncaught.
In addit |
https://en.wikipedia.org/wiki/Sodium%20bisulfate | Sodium bisulfate, also known as sodium hydrogen sulfate, is the sodium salt of the bisulfate anion, with the molecular formula NaHSO4. Sodium bisulfate is an acid salt formed by partial neutralization of sulfuric acid by an equivalent of sodium base, typically in the form of either sodium hydroxide (lye) or sodium chloride (table salt). It is a dry granular product that can be safely shipped and stored. The anhydrous form is hygroscopic. Solutions of sodium bisulfate are acidic, with a 1M solution having a pH of slightly below 1.
Production
Sodium bisulfate is produced as an intermediate in the Mannheim process, an industrial process involving the reaction of sodium chloride and sulfuric acid:
NaCl + H2SO4 → HCl + NaHSO4
The process for the formation of sodium bisulfate is highly exothermic. The liquid sodium bisulfate is sprayed and cooled so that it forms a solid bead. The hydrogen chloride gas is dissolved in water to produce hydrochloric acid as a useful coproduct of the reaction.
Sodium bisulfate can be generated as a byproduct of the production of many other mineral acids via the reaction of their sodium salts with an excess of sulfuric acid:
NaX + H2SO4 → NaHSO4 + HX ( X− = CN−, NO3−, ClO4−)
The acids HX produced have a lower boiling point than the reactants and are separated from the reaction mixture by distillation.
Chemical reactions
Hydrated sodium bisulfate dehydrates at at which point it separates from the water molecule attached to it. Once cooled again, it is freshly hygroscopic. Heating sodium bisulfate to produces sodium pyrosulfate, another colorless salt:
2 NaHSO4 → Na2S2O7 + H2O
Uses
Sodium bisulfate is used primarily to lower pH. it also is used in metal finishing, cleaning products, and to lower the pH of water for effective chlorination in swimming pools and hot tubs. Sodium bisulfate is also AAFCO approved as a general-use feed additive, including use in poultry feed and companion animal food. It is used as a urine acidifie |
https://en.wikipedia.org/wiki/WalkSAT | In computer science, GSAT and WalkSAT are local search algorithms to solve Boolean satisfiability problems.
Both algorithms work on formulae in Boolean logic that are in, or have been converted into conjunctive normal form. They start by assigning a random value to each variable in the formula. If the assignment satisfies all clauses, the algorithm terminates, returning the assignment. Otherwise, a variable is flipped and the above is then repeated until all the clauses are satisfied. WalkSAT and GSAT differ in the methods used to select which variable to flip.
GSAT makes the change which minimizes the number of unsatisfied clauses in the new assignment, or with some probability picks a variable at random.
WalkSAT first picks a clause which is unsatisfied by the current assignment, then flips a variable within that clause. The clause is picked at random among unsatisfied clauses. The variable is picked that will result in the fewest previously satisfied clauses becoming unsatisfied, with some probability of picking one of the variables at random. When picking at random, WalkSAT is guaranteed at least a chance of one out of the number of variables in the clause of fixing a currently incorrect assignment. When picking a guessed-to-be-optimal variable, WalkSAT has to do less calculation than GSAT because it is considering fewer possibilities.
Both algorithms may restart with a new random assignment if no solution has been found for too long, as a way of getting out of local minima of numbers of unsatisfied clauses.
Many versions of GSAT and WalkSAT exist. WalkSAT has been proven particularly useful in solving satisfiability problems produced by conversion from automated planning problems. The approach to planning that converts planning problems into Boolean satisfiability problems is called satplan.
MaxWalkSAT is a variant of WalkSAT designed to solve the weighted satisfiability problem, in which each clause has associated with a weight, and the goal is to find |
https://en.wikipedia.org/wiki/Backbone%20network | A backbone or core network is a part of a computer network which interconnects networks, providing a path for the exchange of information between different LANs or subnetworks. A backbone can tie together diverse networks in the same building, in different buildings in a campus environment, or over wide areas. Normally, the backbone's capacity is greater than the networks connected to it.
A large corporation that has many locations may have a backbone network that ties all of the locations together, for example, if a server cluster needs to be accessed by different departments of a company that are located at different geographical locations. The pieces of the network connections (for example: Ethernet, wireless) that bring these departments together is often mentioned as network backbone. Network congestion is often taken into consideration while designing backbones.
One example of a backbone network is the Internet backbone.
History
The theory, design principles, and first instantiation of the backbone network came from the telephone core network when traffic was purely voice. The core network was the central part of a telecommunications network that provided various services to customers who were connected by the access network. One of the main functions was to route telephone calls across the PSTN.
Typically the term referred to the high capacity communication facilities that connect primary nodes. A core network provided paths for the exchange of information between different sub-networks.
In the United States, local exchange core networks were linked by several competing interexchange networks; in the rest of the world, the core network has been extended to national boundaries.
Core networks usually had a mesh topology that provided any-to-any connections among devices on the network. Many main service providers would have their own core/backbone networks that are interconnected. Some large enterprises have their own core/backbone network, which are typ |
https://en.wikipedia.org/wiki/N-Acetylglucosamine | N-Acetylglucosamine (GlcNAc) is an amide derivative of the monosaccharide glucose. It is a secondary amide between glucosamine and acetic acid. It is significant in several biological systems.
It is part of a biopolymer in the bacterial cell wall, which is built from alternating units of GlcNAc and N-acetylmuramic acid (MurNAc), cross-linked with oligopeptides at the lactic acid residue of MurNAc. This layered structure is called peptidoglycan (formerly called murein).
GlcNAc is the monomeric unit of the polymer chitin, which forms the exoskeletons of arthropods like insects and crustaceans. It is the main component of the radulas of mollusks, the beaks of cephalopods, and a major component of the cell walls of most fungi.
Polymerized with glucuronic acid, it forms hyaluronan.
GlcNAc has been reported to be an inhibitor of elastase release from human polymorphonuclear leukocytes (range 8–17% inhibition), however this is much weaker than the inhibition seen with N-acetylgalactosamine (range 92–100%).
Medical uses
It has been proposed as a treatment for autoimmune diseases and recent tests have claimed some success.
O-GlcNAcylation
O-GlcNAcylation is the process of adding a single N-acetylglucosamine sugar to the serine or threonine of a protein. Comparable to phosphorylation, addition or removal of N-acetylglucosamine is a means of activating or deactivating enzymes or transcription factors. In fact, O-GlcNAcylation and phosphorylation often compete for the same serine/threonine sites. O-GlcNAcylation most often occurs on chromatin proteins, and is often seen as a response to stress.
Hyperglycemia increases O-GlcNAcylation, leading to insulin resistance. Increased O-GlcNAcylation due to hyperglycemia is evidently a dysfunctional form of O-GlcNAcylation. O-GlcNAcylation decline in the brain with age is associated with cognitive decline. When O-GlcNAcylation was increased in the hippocampus of aged mice, spatial learning and memory improved.
See also
Kerata |
https://en.wikipedia.org/wiki/M2%20proton%20channel | The Matrix-2 (M2) protein is a proton-selective viroporin, integral in the viral envelope of the influenza A virus. The channel itself is a homotetramer (consists of four identical M2 units), where the units are helices stabilized by two disulfide bonds, and is activated by low pH. The M2 protein is encoded on the seventh RNA segment together with the M1 protein. Proton conductance by the M2 protein in influenza A is essential for viral replication.
Influenza B and C viruses encode proteins with similar function dubbed "BM2" and "CM2" respectively. They share little similarity with M2 at the sequence level, despite a similar overall structure and mechanism.
Structure
In influenza A virus, M2 protein unit consists of three protein segments comprising 97 amino acid residues: (i) an extracellular N-terminal domain (residues 1–23); (ii) a transmembrane segment (TMS) (residues 24–46); (iii) an intracellular C-terminal domain (residues 47–97). The TMS forms the pore of the ion channel. The important residues are the imidazole of His37 (pH sensor) and the indole of Trp41 (gate). This domain is the target of the anti influenza drugs, amantadine and its ethyl derivative rimantadine, and probably also the methyl derivative of rimantadine, adapromine. The first 17 residues of the M2 cytoplasmic tail form a highly conserved amphipathic helix.
The amphipathic helix residues (46–62) within the cytoplasmic tail play role in virus budding and assembly. The influenza virus utilizes these amphipathic helices in M2 to alter membrane curvature at the budding neck of the virus in a cholesterol dependent manner. The residues 70–77 of cytoplasmic tail are important for binding to M1 and for the efficient production of infectious virus particles. This region also contains a caveolin binding domain (CBD). The C-terminal end of the channel extends into a loop (residues 47–50) that connects the trans membrane domain to the C-terminal amphipathic helix. (46–62). Two different high-resolut |
https://en.wikipedia.org/wiki/Ambient%20space%20%28mathematics%29 | In mathematics, especially in geometry and topology, an ambient space is the space surrounding a mathematical object along with the object itself. For example, a 1-dimensional line may be studied in isolation —in which case the ambient space of is , or it may be studied as an object embedded in 2-dimensional Euclidean space —in which case the ambient space of is , or as an object embedded in 2-dimensional hyperbolic space —in which case the ambient space of is . To see why this makes a difference, consider the statement "Parallel lines never intersect." This is true if the ambient space is , but false if the ambient space is , because the geometric properties of are different from the geometric properties of . All spaces are subsets of their ambient space.
See also
Configuration space
Geometric space
Manifold and ambient manifold
Submanifolds and Hypersurfaces
Riemannian manifolds
Ricci curvature
Differential form |
https://en.wikipedia.org/wiki/Genetic%20use%20restriction%20technology | Genetic use restriction technology (GURT), also known as terminator technology or suicide seeds, is the name given to proposed methods for restricting the use of genetically modified crops by activating (or deactivating) some genes only in response to certain stimuli, especially to cause second generation seeds to be infertile. The development and application of GURTs is primarily an attempt by private sector agricultural breeders to increase the extent of protection on their innovations. The technology was originally developed under a cooperative research and development agreement between the Agricultural Research Service of the United States Department of Agriculture and Delta & Pine Land Company in the 1990s and is not yet commercially available.
GURT was first reported on by the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) to the UN Convention on Biological Diversity and discussed during the 8th Conference of the Parties to the United Nations Convention on Biological Diversity in Curitiba, Brazil, March 20–31, 2006.
Process
Because of the continued development of the technology and the continued protection of patents that develop it, many descriptions of GURT differ from others. Even so, the basic description of many GURTs are similar. The process is typically composed of four genetic components: a target gene, a promoter, a trait switch, and a genetic switch, sometimes with slightly different names in different papers.
For example, a typical GURT works similarly to as follows: a plant with GURT technology has a target gene in its DNA that expresses when activated by a promoter gene. However, it is separated from the gene by a blocker sequence that prevents the promoter from accessing the target. When the plant receives a given external input, a genetic switch in the plant takes the input, amplifies it, and converts it into a biological signal. When a trait switch receives the amplified signal, it creates an enzyme that cuts the |
https://en.wikipedia.org/wiki/Multi-armed%20bandit | In probability theory and machine learning, the multi-armed bandit problem (sometimes called the K- or N-armed bandit problem) is a problem in which a fixed limited set of resources must be allocated between competing (alternative) choices in a way that maximizes their expected gain, when each choice's properties are only partially known at the time of allocation, and may become better understood as time passes or by allocating resources to the choice. This is a classic reinforcement learning problem that exemplifies the exploration–exploitation tradeoff dilemma. The name comes from imagining a gambler at a row of slot machines (sometimes known as "one-armed bandits"), who has to decide which machines to play, how many times to play each machine and in which order to play them, and whether to continue with the current machine or try a different machine. The multi-armed bandit problem also falls into the broad category of stochastic scheduling.
In the problem, each machine provides a random reward from a probability distribution specific to that machine, that is not known a-priori. The objective of the gambler is to maximize the sum of rewards earned through a sequence of lever pulls. The crucial tradeoff the gambler faces at each trial is between "exploitation" of the machine that has the highest expected payoff and "exploration" to get more information about the expected payoffs of the other machines. The trade-off between exploration and exploitation is also faced in machine learning. In practice, multi-armed bandits have been used to model problems such as managing research projects in a large organization, like a science foundation or a pharmaceutical company. In early versions of the problem, the gambler begins with no initial knowledge about the machines.
Herbert Robbins in 1952, realizing the importance of the problem, constructed convergent population selection strategies in "some aspects of the sequential design of experiments". A theorem, the Gittins ind |
https://en.wikipedia.org/wiki/Degree%20day | A degree day is a measure of heating or cooling. Total degree days from an appropriate starting date are used to plan the planting of crops and management of pests and pest control timing. Weekly or monthly degree-day figures may also be used within an energy monitoring and targeting scheme to monitor the heating and cooling costs of climate controlled buildings, while annual figures can be used for estimating future costs.
A degree day is computed as the integral of a function of time that generally varies with temperature. The function is truncated to upper and lower limits that vary by organism, or to limits that are appropriate for climate control. The function can be estimated or measured by one of the following methods, in each case by reference to a chosen base temperature:
Frequent measurements and continuously integrating the temperature deficit or excess;
Treating each day's temperature profile as a sine wave with amplitude equal to the day's temperature variation, measured from max and min, and totalling the daily results;
As above, but calculating the daily difference between mean temperature and base temperature;
As previous, but with modified formulae on days when the max and min straddle the base temperature.
A zero degree-day in energy monitoring and targeting is when either heating or cooling consumption is at a minimum, which is useful with power utility companies in predicting seasonal low points in energy demand.
Degree days are a useful metric for estimating energy consumption required for household heating and cooling, and in this context are formally referred to as heating degree days. Since the escape or ingress of heat due to conduction is proportional to the difference between the indoor and outdoor temperature, the amount of energy needed to maintain the base temperature indoors for some period of time is roughly proportional to the number of degree days. For example, if the base temperature is and the outdoor temperature is consta |
https://en.wikipedia.org/wiki/Age%20class%20structure | Age class structure in fisheries and wildlife management is a part of population assessment. Age class structures can be used to model many populations including trees and fish. This method can be used to predict the occurrence of forest fires within a forest population. Age can be determined by counting growth rings in fish scales, otoliths, cross-sections of fin spines for species with thick spines such as triggerfish, or teeth for a few species. Each method has its merits and drawbacks. Fish scales are easiest to obtain, but may be unreliable if scales have fallen off the fish and new ones grown in their places. Fin spines may be unreliable for the same reason, and most fish do not have spines of sufficient thickness for clear rings to be visible. Otoliths will have stayed with the fish throughout its life history, but obtaining them requires killing the fish. Also, otoliths often require more preparation before ageing can occur.
Analyzing fisheries age class structure
An example of using age class structure to learn about a population is a regular bell curve for the population of 1-5 year-old fish with a very low population for the 3-year-olds. An age class structure with gaps in population size like the one described earlier implies a bad spawning year 3 years ago in that species.
Often fish in younger age class structures have very low numbers because they were small enough to slip through the sampling nets, and may in fact have a very healthy population.
See also
Identification of aging in fish
Population pyramid
Population dynamics of fisheries |
https://en.wikipedia.org/wiki/Amaranthus%20hybridus | Amaranthus hybridus, commonly called green amaranth, slim amaranth, smooth amaranth, smooth pigweed, or red amaranth, is a species of annual flowering plant. It is a weedy species found now over much of North America and introduced into Europe and Eurasia.
Description
Amaranthus hybridus grows from a short taproot and can be up to 2.5 m in height. It is a glabrous or glabrescent plant.
Distribution
Amaranthus hybridus was originally a pioneer plant in eastern North America. It has been reported to have been found in every state except Wyoming, Utah, and Alaska. It is also found in many provinces of Canada, and in parts of Mexico, the West Indies, Central America, and South America. It has been naturalized in many places of warmer climate. It grows in many different places, including disturbed habitats.
Taxonomy
It is extremely variable, and many other Amaranthus species are believed to be natural hybridizations or derive from A. hybridus.
As a weed
Although easily controlled and not particularly competitive, it is recognized as a harmful weed of North American crops.
Uses
The seeds and cooked leaves are edible.
The plant was used for food and medicine by several Native American groups and in traditional African medicine. It is among the species consumed as Quelite quintonilli in Mexican food markets. |
https://en.wikipedia.org/wiki/Limits%20of%20computation | The limits of computation are governed by a number of different factors. In particular, there are several physical and practical limits to the amount of computation or data storage that can be performed with a given amount of mass, volume, or energy.
Hardware limits or physical limits
Processing and memory density
The Bekenstein bound limits the amount of information that can be stored within a spherical volume to the entropy of a black hole with the same surface area.
Thermodynamics limit the data storage of a system based on its energy, number of particles and particle modes. In practice, it is a stronger bound than the Bekenstein bound.
Processing speed
Bremermann's limit is the maximum computational speed of a self-contained system in the material universe, and is based on mass–energy versus quantum uncertainty constraints.
Communication delays
The Margolus–Levitin theorem sets a bound on the maximum computational speed per unit of energy: 6 × 1033 operations per second per joule. This bound, however, can be avoided if there is access to quantum memory. Computational algorithms can then be designed that require arbitrarily small amounts of energy/time per one elementary computation step.
Energy supply
Landauer's principle defines a lower theoretical limit for energy consumption: consumed per irreversible state change, where k is the Boltzmann constant and T is the operating temperature of the computer. Reversible computing is not subject to this lower bound. T cannot, even in theory, be made lower than 3 kelvins, the approximate temperature of the cosmic microwave background radiation, without spending more energy on cooling than is saved in computation. However, on a timescale of 109 – 1010 years, the cosmic microwave background radiation will be decreasing exponentially, which has been argued to eventually enable 1030 as much computations per unit of energy. Important parts of this argument have been disputed.
Building devices that approach |
https://en.wikipedia.org/wiki/Vascularity | Vascularity, in bodybuilding, is the condition of having many highly visible, prominent, and often extensively-ramified superficial veins. The skin appears "thin"—sometimes virtually transparent—due to an extreme reduction of subcutaneous fat, allowing for maximum muscle definition.
Vascularity is enhanced by extremely low body fat (usually below 10%) and low retained water, as well as the muscle engorgement ("pump") and venous distension accentuated by the vigorous flexing and potentially hazardous Valsalva effect which characterize competitive posing. Genetics and androgenic hormones will affect vascularity, as will ambient temperature. Additionally, although some bodybuilders develop arterial hypertension from performance-enhancing substances and practices, "high" venous pressure—being an order of magnitude lower than that of arteries— neither causes nor is caused by vascularity. Some bodybuilders use topical vasodilators to increase blood flow to the skin as well. Although historically controversial, vascularity is a highly-sought-after aesthetic for many male bodybuilders, but less so for female bodybuilders, where the target aesthetic is relatively more towards aesthetic symmetry than extreme development.
Bodybuilders or athletes sometimes dehydrate themselves a few days before a competition or show to achieve this so-called "ripped," vascular look. Self-dehydration is not recommended by medical professionals, as the negative and sometimes-fatal effects of the resultant water-electrolyte imbalances are well documented. |
https://en.wikipedia.org/wiki/Depletion-load%20NMOS%20logic | In integrated circuits, depletion-load NMOS is a form of digital logic family that uses only a single power supply voltage, unlike earlier NMOS (n-type metal-oxide semiconductor) logic families that needed more than one different power supply voltage. Although manufacturing these integrated circuits required additional processing steps, improved switching speed and the elimination of the extra power supply made this logic family the preferred choice for many microprocessors and other logic elements.
Depletion-mode n-type MOSFETs as load transistors allow single voltage operation and achieve greater speed than possible with pure enhancement-load devices. This is partly because the depletion-mode MOSFETs can be a better current source approximation than the simpler enhancement-mode transistor can, especially when no extra voltage is available (one of the reasons early PMOS and NMOS chips demanded several voltages).
The inclusion of depletion-mode NMOS transistors in the manufacturing process demanded additional manufacturing steps compared to the simpler enhancement-load circuits; this is because depletion-load devices are formed by increasing the amount of dopant in the load transistors channel region, in order to adjust their threshold voltage. This is normally performed using ion implantation.
Although the CMOS process replaced most NMOS designs during the 1980s, some depletion-load NMOS designs are still produced, typically in parallel with newer CMOS counterparts. One example of this is the Z84015 and Z84C15.
History and background
Following the invention of the MOSFET by Mohamed Atalla and Dawon Kahng at Bell Labs in 1959, they demonstrated MOSFET technology in 1960. They fabricated both PMOS and NMOS devices with a 20µm process. However, the NMOS devices were impractical, and only the PMOS type were practical working devices.
In 1965, Chih-Tang Sah, Otto Leistiko and A.S. Grove at Fairchild Semiconductor fabricated several NMOS devices with channel len |
https://en.wikipedia.org/wiki/Plantsman | A plantsman is an enthusiastic and knowledgeable gardener (amateur or professional), nurseryman or nurserywoman. "Plantsman" can refer to a male or female person, though the terms plantswoman, or even plantsperson, are sometimes used. The word is sometimes said to be synonymous with "botanist" or "horticulturist", but that would indicate a professional involvement, whereas "plantsman" reflects an attitude to (and perhaps even an obsession with) plants. A horticulturist may be a plantsman, but a plantsman is not necessarily a horticulturist.
Defining the word
In the first edition (June 1979) of The Plantsman (a specialist magazine, published by the Royal Horticultural Society from 1994 until June 2019, when it was announced that the title would be changed to The Plant Review), Sandra Raphael (then a senior editor in the Dictionary Department of the Oxford University Press) contributed a short article on the history and meaning of the word. Her first example came from an issue of the Gardeners' Chronicle of 1881, when it seemed to mean "A nurseryman, a florist" (in the early sense of "florist" as a grower and breeder of flowers, rather than the more recent meaning of someone who sells or arranges them). She added that a modern definition should point out that "plantsman"
"…is usually intended to mean a connoisseur of plants or an expert gardener."
In her article, Raphael also quotes botanist David McClintock (writing in the Botanical Society of the British Isles' BSBI News, December 1976) on how to distinguish a botanist from a plantsman, beginning with the simple definition:
"A plantsman is one who loves plants for their own sake and knows how to cherish them. This… concept… may include a botanist: it certainly includes a host of admirable amateurs who may not know what a chromosome looks like or what taxonomy means, but they know the growing plant, wild or cultivated, first-hand. To my mind they are the cream of those in the plant world, a fund of invaluable firs |
https://en.wikipedia.org/wiki/Karp%E2%80%93Lipton%20theorem | In complexity theory, the Karp–Lipton theorem states that if the Boolean satisfiability problem (SAT) can be solved by Boolean circuits with a polynomial number of logic gates, then
and therefore
That is, if we assume that NP, the class of nondeterministic polynomial time problems, can be contained in the non-uniform polynomial time complexity class P/poly, then this assumption implies the collapse of the polynomial hierarchy at its second level. Such a collapse is believed unlikely, so the theorem is generally viewed by complexity theorists as evidence for the nonexistence of polynomial size circuits for SAT or for other NP-complete problems. A proof that such circuits do not exist would imply that P ≠ NP. As P/poly contains all problems solvable in randomized polynomial time (Adleman's theorem), the theorem is also evidence that the use of randomization does not lead to polynomial time algorithms for NP-complete problems.
The Karp–Lipton theorem is named after Richard M. Karp and Richard J. Lipton, who first proved it in 1980. (Their original proof collapsed PH to , but Michael Sipser improved it to .)
Variants of the theorem state that, under the same assumption, MA = AM, and PH collapses to complexity class. There are stronger conclusions possible if PSPACE, or some other complexity classes are assumed to have polynomial-sized circuits; see P/poly. If NP is assumed to be a subset of BPP (which is a subset of P/poly), then the polynomial hierarchy collapses to BPP. If coNP is assumed to be subset of NP/poly, then the polynomial hierarchy collapses to its third level.
Intuition
Suppose that polynomial sized circuits for SAT not only exist, but also that they could be constructed by a polynomial time algorithm. Then this supposition implies that SAT itself could be solved by a polynomial time algorithm that constructs the circuit and then applies it. That is, efficiently constructible circuits for SAT would lead to a stronger collapse, P = NP.
The assump |
https://en.wikipedia.org/wiki/Higher-order%20programming | Higher-order programming is a style of computer programming that uses software components, like functions, modules or objects, as values. It is usually instantiated with, or borrowed from, models of computation such as lambda calculus which make heavy use of higher-order functions. A programming language can be considered higher-order if components, such as procedures or labels, can be used just like data. For example, these elements could be used in the same way as arguments or values.
For example, in higher-order programming, one can pass functions as arguments to other functions and functions can be the return value of other functions (such as in macros or for interpreting). This style of programming is mostly used in functional programming, but it can also be very useful in object-oriented programming. A slightly different interpretation of higher-order programming in the context of object-oriented programming are higher order messages, which let messages have other messages as arguments, rather than functions.
Examples of languages supporting this are Wolfram Language, C#, Java, ECMAScript (ActionScript, JavaScript, JScript), F#, Haskell, Lisp (Common Lisp, Scheme, Clojure, others), Lua, Oz, Perl, PHP, Prolog, Python, Ruby, Smalltalk, Scala, ML, and Erlang.
See also
Prolog#Higher-order programming
Higher-order logic programming |
https://en.wikipedia.org/wiki/Caleb%20Gattegno | Caleb Gattegno (1911–1988) was an Egyptian educator, psychologist, and mathematician. He is considered one of the most influential and prolific mathematics educators of the twentieth century. He is best known for introducing new approaches to teaching and learning mathematics (Visible & Tangible Math), foreign languages (The Silent Way) and reading (Words in Color). Gattegno also developed pedagogical materials for each of these approaches, and was the author of more than 120 books and hundreds of articles largely on the topics of education and human development.
Background
Gattegno was born November 11, 1911, in Alexandria, Egypt. His parents, Menachem Gattegno, a Spanish merchant, and his wife, Bchora, had nine children. Because of poverty, Gattegno and his siblings had to work starting from a young age. The future mathematician had no formal education until he started to learn on his own at the age of 14. He took external examinations when he was 20 years old and obtained a teaching license in physics and chemistry from the University of Marseille in Cairo.
He moved to England, where he became involved in teacher education and helped establish the Association of Teachers of Mathematics and the International Commission for the Study and Improvement of Mathematics Teaching. He taught at several universities including the University of Liverpool and the University of London.
Pedagogical approach
Gattegno's pedagogical approach is characterised by propositions based on the observation of human learning in many and varied situations. This is a description of three of these propositions. He was also influenced by the works of Jean Piaget and worked on introducing the implications of the latter's cognitive theory on education.
Learning and effort
Gattegno noticed that there is an "energy budget" for learning. Human beings have a highly developed sense of the economics of their own energy and are very sensitive to the cost involved in using it. It is therefore esse |
https://en.wikipedia.org/wiki/Strongly%20correlated%20material | Strongly correlated materials are a wide class of compounds that include insulators and electronic materials, and show unusual (often technologically useful) electronic and magnetic properties, such as metal-insulator transitions, heavy fermion behavior, half-metallicity, and spin-charge separation. The essential feature that defines these materials is that the behavior of their electrons or spinons cannot be described effectively in terms of non-interacting entities. Theoretical models of the electronic (fermionic) structure of strongly correlated materials must include electronic (fermionic) correlation to be accurate. As of recently, the label quantum materials is also used to refer to strongly correlated materials, among others.
Transition metal oxides
Many transition metal oxides belong to this class which may be subdivided according to their behavior, e.g. high-Tc, spintronic materials, multiferroics, Mott insulators, spin Peierls materials, heavy fermion materials, quasi-low-dimensional materials, etc. The single most intensively studied effect is probably high-temperature superconductivity in doped cuprates, e.g. La2−xSrxCuO4. Other ordering or magnetic phenomena and temperature-induced phase transitions in many transition-metal oxides are also gathered under the term "strongly correlated materials."
Electronic structures
Typically, strongly correlated materials have incompletely filled d- or f-electron shells with narrow energy bands. One can no longer consider any electron in the material as being in a "sea" of the averaged motion of the others (also known as mean field theory). Each single electron has a complex influence on its neighbors.
The term strong correlation refers to behavior of electrons in solids that is not well-described (often not even in a qualitatively correct manner) by simple one-electron theories such as the local-density approximation (LDA) of density-functional theory or Hartree–Fock theory. For instance, the seemingly simple ma |
https://en.wikipedia.org/wiki/Now%20TV%20%28Hong%20Kong%29 | Now TV (also stylised as now TV) is a pay-TV service provider in Hong Kong operated by PCCW Media Limited, a wholly owned subsidiary of PCCW. Launched on 26 September 2003, its TV signal is transmitted with IPTV technology through HKT's fixed broadband network.
It no
N
provides 197 TV channels including 176 channels branded under now TV (32 channels in HD), 21 channels from TVB Network Vision (1 channel in HD), and over 30 video on demand categories.
Now TV is the largest pay-TV operator in Hong Kong in terms of number of subscribers, number of channels, number of HD channels and quantity of VOD contents. The word "Now" is abbreviated from "Network Of the World".
History and establishment
Launched in March 1998, PCCW's services included a wide range of information and entertainment, such as news, video-on-demand (VOD), music videos, home-shopping, home-banking and educational content. iTV had some 67,000 subscribers at the end of 2000.
Due to the liberalization of the pay-TV market by the HKSAR government in early July 2000, the then existing duopolists, iTV and i-Cable, were confronted with ferocious competition. With fewer subscribers and hence the decline in the revenue generated from iTV, the interactive television operation was terminated in the final quarter of 2002. Now Broadband pay-TV service was launched in September 2003 with 23 channels under the same umbrella company PCCW; iTV is thus commonly viewed as the predecessor of Now TV.
In December 2005, Now TV introduced a technology with connection speed up to 18 megabits per second (Mbit/s). At least 75% of the service area will be offered a service running up to 8Mbit/s. In addition, Video-On-Demand services were launched in January 2006.
Now TV subscribers have access to 136 channels.
Chronology
March 1998 Hong Kong Telecom commercially launched iTV
July 2000 Liberalisation of the pay-TV market
Last quarter of 2002 Termination of iTV
August 2003 Now TV was unveiled
September 2003 Now TV was offi |
https://en.wikipedia.org/wiki/Triangulated%20irregular%20network | In computer graphics, a triangulated irregular network (TIN) is a representation of a continuous surface consisting entirely of triangular facets (a triangle mesh), used mainly as Discrete Global Grid in primary elevation modeling.
The vertices of these triangles are created from field recorded spot elevations through a variety of means including surveying through conventional techniques, Global Positioning System Real-Time Kinematic (GPS RTK), photogrammetry, or some other means. Associated with three-dimensional data and topography, TINs are useful for the description and analysis of general horizontal distributions and relationships.
Digital TIN data structures are used in a variety of applications, including geographic information systems (GIS), and computer aided design (CAD) for the visual representation of a topographical surface. A TIN is a vector-based representation of the physical land surface or sea bottom, made up of irregularly distributed nodes and lines with three-dimensional coordinates that are arranged in a network of non-overlapping triangles.
A TIN comprises a triangular network of vertices, known as mass points, with associated coordinates in three dimensions connected by edges to form a triangular tessellation. Three-dimensional visualizations are readily created by rendering of the triangular facets. In regions where there is little variation in surface height, the points may be widely spaced whereas in areas of more intense variation in height the point density is increased.
A TIN used to represent terrain is often called a digital elevation model (DEM), which can be further used to produce digital surface models (DSM) or digital terrain models (DTM). An advantage of using a TIN over a rasterized digital elevation model (DEM) in mapping and analysis is that the points of a TIN are distributed variably based on an algorithm that determines which points are most necessary to create an accurate representation of the terrain. Data inpu |
https://en.wikipedia.org/wiki/Norman%20Packard | Norman Harry Packard (born 1954 in Billings, Montana) is a chaos theory physicist and one of the founders of the Prediction Company and ProtoLife. He is an alumnus of Reed College and the University of California, Santa Cruz. Packard is known for his contributions to chaos theory, complex systems, and artificial life. He coined the phrase "the edge of chaos".
Biography
Between 1976 and 1981, Packard formed the Dynamical Systems Collective at UC Santa Cruz with fellow physics graduate students, Rob Shaw, Doyne Farmer, and James Crutchfield. The collective was best known for its work in probing chaotic systems for signs of order.
Around the same time, he worked with Doyne Farmer and other friends in Santa Cruz, California to form the Eudaemons collective , to develop a strategy for beating the roulette wheel using a toe-operated computer. The computer could, in theory, predict in what area a roulette ball would land on a wheel, giving the player a significant statistical advantage over the house. Although the project itself was a success, they ran into practical difficulty employing the technique on-site in Las Vegas casinos. The experiences of Norman, Doyne Farmer, and crew were later chronicled in the book The Eudaemonic Pie (1985) by Thomas Bass. Their experience was also chronicled on the History Channel television series "Breaking Vegas."
In 1982, Packard won a NATO post-doctoral fellowship to study at the Institut des Hautes Études Scientifiques in Bures-sur-Yvette, France. One year later, he joined the Princeton Institute for Advanced Study. At the IAS, he worked with colleagues Stephen Wolfram and Rob Shaw to explain complex systems and the tendency for matter to organize itself. Subsequently, Packard has made contributions to the field of Artificial Life, including the definition of Evolutionary Activity.
Professional work
Center for Complex Systems Research
In 1985 Packard moved with Wolfram to the physics department of the University of Illinois, |
https://en.wikipedia.org/wiki/Lucien%20LaCoste | Lucien LaCoste (1908 – 1995) was a physicist and metrologist. He coinvented the modern gravimeter and invented the zero-length spring and vehicle-mounted gravimeters. He was also co-founder of LaCoste Romberg, a prominent company selling gravimetric instruments.
Life
LaCoste discovered the zero-length spring in 1932 while performing an assignment in Arnold Romberg's undergraduate physics course. A zero-length spring is a spring supported in such a way that its exerted force is proportional to its length, rather than the distance it is compressed. That is, over at least part of its travel, it does not conform to Hooke's Law of spring compression.
The zero-length spring is extremely important to seismometers and gravimeters because it permits the design of vertical pendulums with (theoretically) infinite periods. In practice, periods of a thousand seconds are possible, a hundredfold increase from other forms of pendulum.
Over a short period starting in 1932, the design of these instruments was revolutionized, obsoleting all previous designs.
During this period, LaCoste and his physics teacher Arnold Romberg invented the first modern seismographs and gravimeters, using steel and quartz (respectively) zero-length springs.
While a graduate student, LaCoste decided to go into business together with Romberg, selling advanced gravimeters to oil-exploration companies.
LaCoste's most famous invention is the ship, and aircraft-mounted gravimeter. These revolutionized exploration for minerals by allowing wide-ranging geological surveys. The chief problem that Lacoste defeated was to distinguish the accelerations of the vehicles from the accelerations due to gravity, and measure the minute changes in gravity. Since the accelerations from the vehicle typically are hundreds to thousands of times more forceful than the measured changes, this invention was considered impossible until LaCoste demonstrated it. |
https://en.wikipedia.org/wiki/Monocarpic | Monocarpic plants are those that flower and set seeds only once, and then die.
The term is derived from Greek (, "single" + , "fruit" or "grain"), and was first used by Alphonse de Candolle. Other terms with the same meaning are hapaxanth and semelparous. The antonym is polycarpic, a plant that flowers and sets seeds many times during its lifetime; the antonym of semelparous is iteroparous. Plants which flower en masse (gregariously) before dying are known as plietesials. The term hapaxanth is most often in conjunction with describing some of the taxa of Arecaceae (palms) and some species of bamboo, but rarely used otherwise; its antonym is pleonanth. This was first used by Alexander Braun.
Monocarpic plants are not necessarily annuals, because some monocarpic plants can live a number of years before they will flower. In some monocarpic plants, flowering signals senescence, while in others the production of fruits and seeds causes changes within the plants which lead to death. These changes are induced by chemicals that act as hormones, redirecting the resources of the plants from the roots and leaves to the production of fruits and or seeds.
The century plant in the genus Agave, some terrestrial bromeliads of the genus Puya, Tillandsia utriculata, some yuccas, and many bamboos can take 8 to 20 years or in the case of some bamboos even over 100 years to bloom and then die. Hawaiian silverswords and their relatives in the genus Wilkesia may take 10–50 years before flowering.
Monocot plant families that include monocarpic species include Agavaceae, Araceae, Arecaceae, Bromeliaceae, Musaceae, and Poaceae. Dicot plant families that include monocarpic species include Acanthaceae, Apocynaceae, Asteraceae, and Fabaceae. Few dicot shrubs with multiple branching and secondary growth species have been described. Those that have include Strobilanthes species, Cerberiopsis candelabrum, Tachigali versicolor and other Tachigali species.
Some monocarpic plants can be kept ali |
https://en.wikipedia.org/wiki/Demersal%20fish | Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone). They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal depths or on the abyssal plain, but they can be found around seamounts and islands. The word demersal comes from the Latin demergere, which means to sink.
Demersal fish are bottom feeders. They can be contrasted with pelagic fish which live and feed away from the bottom in the open water column.
Demersal fish fillets contain little fish oil (one to four per cent), whereas pelagic fish can contain up to 30 per cent.
Types
Demersal fish can be divided into two main types: strictly benthic fish which can rest on the sea floor, and benthopelagic fish which can float in the water column just above the sea floor.
Benthopelagic fish have neutral buoyancy, so they can float at depth without much effort, while strictly benthic fish are denser, with negative buoyancy so they can lie on the bottom without any effort. Most demersal fish are benthopelagic.
As with other bottom feeders, a mechanism to deal with substrate is often necessary. With demersal fish the sand is usually pumped out of the mouth through the gill slit. Most demersal fish exhibit a flat ventral region so as to more easily rest their body on the substrate. The exception may be the flatfish, which are laterally depressed but lie on their sides. Also, many exhibit what is termed an "inferior" mouth, which means that the mouth is pointed downwards; this is beneficial as their food is often below them in the substrate. Those bottom feeders with upward-pointing mouths, such as stargazers, tend to seize swimming prey.
Benthic fish
Benthic fish are denser than water, so they |
https://en.wikipedia.org/wiki/Kohnstamm%27s%20phenomenon | First described by German neurologist Oskar Kohnstamm (1871–1917) in 1915, Kohnstamm's phenomenon is a sustained involuntary contraction of a muscle after a prolonged voluntary contraction. The simplest demonstration, sometimes called "the floating arms experiment", is to have a subject press the arms against a door frame or wall for about thirty seconds, and then step away. The arm will involuntarily rise.
Russian scientists Victor Gurfinkel, Mikhail Lebedev and Yuri Levick used Kohnstamm's phenomenon to activate tonogenic structures in humans and thereby demonstrate postural automatisms, such as neck reflexes.
See also
Motor control |
https://en.wikipedia.org/wiki/Pipeline%20video%20inspection | Pipeline video inspection is a form of telepresence used to visually inspect the interiors of pipelines, plumbing systems, and storm drains. A common application is for a plumber to determine the condition of small diameter sewer lines and household connection drain pipes.
Older sewer lines of small diameter, typically , are made by the union of a number of short sections. The pipe segments may be made of cast iron, with to sections, but are more often made of vitrified clay pipe (VCP), a ceramic material, in , & sections. Each iron or clay segment will have an enlargement (a "bell") on one end to receive the end of the adjacent segment. Roots from trees and vegetation may work into the joins between segments and can be forceful enough to break open a larger opening in terra cotta or corroded cast iron. Eventually a root ball will form that will impede the flow and this may cleaned out by a cutter mechanism or plumber's snake and subsequently inhibited by use of a chemical foam - a rooticide.
With modern video equipment, the interior of the pipe may be inspected - this is a form of non-destructive testing. A small diameter collector pipe will typically have a cleanout access at the far end and will be several hundred feet long, terminating at a manhole. Additional collector pipes may discharge at this manhole and a pipe (perhaps of larger diameter) will carry the effluent to the next manhole, and so forth to a pump station or treatment plant.
Without regular inspection of public sewers, a significant amount of waste may accumulate unnoticed until the system fails. In order to prevent resulting catastrophic events such as pipe bursts and raw sewage flooding onto city streets, municipalities usually conduct pipeline video inspections as a precautionary measure.
Inspection equipment
Service truck
The service truck contains a power supply in the form of a small generator, a small air-conditioned compartment containing video monitoring and recording equipment, |
https://en.wikipedia.org/wiki/Metabotropic%20glutamate%20receptor | The metabotropic glutamate receptors, or mGluRs, are a type of glutamate receptor that are active through an indirect metabotropic process. They are members of the group C family of G-protein-coupled receptors, or GPCRs. Like all glutamate receptors, mGluRs bind with glutamate, an amino acid that functions as an excitatory neurotransmitter.
Function and structure
The mGluRs perform a variety of functions in the central and peripheral nervous systems: For example, they are involved in learning, memory, anxiety, and the perception of pain. They are found in pre- and postsynaptic neurons in synapses of the hippocampus, cerebellum, and the cerebral cortex, as well as other parts of the brain and in peripheral tissues.
Like other metabotropic receptors, mGluRs have seven transmembrane domains that span the cell membrane. Unlike ionotropic receptors, metabotropic glutamate receptors are not ion channels. Instead, they activate biochemical cascades, leading to the modification of other proteins, such as ion channels. This can lead to changes in the synapse's excitability, for example by presynaptic inhibition of neurotransmission, or modulation and even induction of postsynaptic responses.
A dimeric organization of mGluRs is required for signaling induced by agonists.
Classification
Eight different types of mGluRs, labeled mGluR1 to mGluR8 ( to ), are divided into groups I, II, and III. Receptor types are grouped based on receptor structure and physiological activity. The mGluRs are further divided into subtypes, such as mGluR7a and mGluR7b.
Overview
Group I
The mGluRs in group I, including mGluR1 and mGluR5, are stimulated most strongly by the excitatory amino acid analog L-quisqualic acid. Stimulating the receptors causes the associated enzyme phospholipase C to hydrolyze phosphoinositide phospholipids in the cell's plasma membrane. This leads to the formation of inositol 1,4,5-trisphosphate (IP3) and diacyl glycerol. Due to its hydrophilic character, IP3 can |
https://en.wikipedia.org/wiki/Electrodynamic%20tether | Electrodynamic tethers (EDTs) are long conducting wires, such as one deployed from a tether satellite, which can operate on electromagnetic principles as generators, by converting their kinetic energy to electrical energy, or as motors, converting electrical energy to kinetic energy. Electric potential is generated across a conductive tether by its motion through a planet's magnetic field.
A number of missions have demonstrated electrodynamic tethers in space, most notably the TSS-1, TSS-1R, and Plasma Motor Generator (PMG) experiments.
Tether propulsion
As part of a tether propulsion system, craft can use long, strong conductors (though not all tethers are conductive) to change the orbits of spacecraft. It has the potential to make space travel significantly cheaper. When direct current is applied to the tether, it exerts a Lorentz force against the magnetic field, and the tether exerts a force on the vehicle. It can be used either to accelerate or brake an orbiting spacecraft.
In 2012 Star Technology and Research was awarded a $1.9 million contract to qualify a tether propulsion system for orbital debris removal.
Uses for ED tethers
Over the years, numerous applications for electrodynamic tethers have been identified for potential use in industry, government, and scientific exploration. The table below is a summary of some of the potential applications proposed thus far. Some of these applications are general concepts, while others are well-defined systems. Many of these concepts overlap into other areas; however, they are simply placed under the most appropriate heading for the purposes of this table. All of the applications mentioned in the table are elaborated upon in the Tethers Handbook. Three fundamental concepts that tethers possess, are gravity gradients, momentum exchange, and electrodynamics. Potential tether applications can be seen below:
ISS reboost
EDT has been proposed to maintain the ISS orbit and save the expense of chemical propellant re |
https://en.wikipedia.org/wiki/Neural%20oscillation | Neural oscillations, or brainwaves, are rhythmic or repetitive patterns of neural activity in the central nervous system. Neural tissue can generate oscillatory activity in many ways, driven either by mechanisms within individual neurons or by interactions between neurons. In individual neurons, oscillations can appear either as oscillations in membrane potential or as rhythmic patterns of action potentials, which then produce oscillatory activation of post-synaptic neurons. At the level of neural ensembles, synchronized activity of large numbers of neurons can give rise to macroscopic oscillations, which can be observed in an electroencephalogram. Oscillatory activity in groups of neurons generally arises from feedback connections between the neurons that result in the synchronization of their firing patterns. The interaction between neurons can give rise to oscillations at a different frequency than the firing frequency of individual neurons. A well-known example of macroscopic neural oscillations is alpha activity.
Neural oscillations in humans were observed by researchers as early as 1924 (by Hans Berger). More than 50 years later, intrinsic oscillatory behavior was encountered in vertebrate neurons, but its functional role is still not fully understood. The possible roles of neural oscillations include feature binding, information transfer mechanisms and the generation of rhythmic motor output. Over the last decades more insight has been gained, especially with advances in brain imaging. A major area of research in neuroscience involves determining how oscillations are generated and what their roles are. Oscillatory activity in the brain is widely observed at different levels of organization and is thought to play a key role in processing neural information. Numerous experimental studies support a functional role of neural oscillations; a unified interpretation, however, is still lacking.
History
Richard Caton discovered electrical activity in the cerebra |
https://en.wikipedia.org/wiki/Q%20value%20%28nuclear%20science%29 | In nuclear physics and chemistry, the value for a reaction is the amount of energy absorbed or released during the nuclear reaction. The value relates to the enthalpy of a chemical reaction or the energy of radioactive decay products. It can be determined from the masses of reactants and products. values affect reaction rates. In general, the larger the positive value for the reaction, the faster the reaction proceeds, and the more likely the reaction is to "favor" the products.
where the masses are in atomic mass units. Also, both and are the sums of the reactant and product masses respectively.
Definition
The conservation of energy, between the initial and final energy of a nuclear process enables the general definition of based on the mass–energy equivalence. For any radioactive particle decay, the kinetic energy difference will be given by:
where denotes the kinetic energy of the mass .
A reaction with a positive value is exothermic, i.e. has a net release of energy, since the kinetic energy of the final state is greater than the kinetic energy of the initial state.
A reaction with a negative value is endothermic, i.e. requires a net energy input, since the kinetic energy of the final state is less than the kinetic energy of the initial state. Observe that a chemical reaction is exothermic when it has a negative enthalpy of reaction, in contrast a positive value in a nuclear reaction.
The value can also be expressed in terms of the Mass excess of the nuclear species as:
Proof The mass of a nucleus can be written as where is the mass number (sum of number of protons and neutrons) and MeV/c. Note that the count of nucleons is conserved in a nuclear reaction. Hence, and .
Applications
Chemical values are measurement in calorimetry. Exothermic chemical reactions tend to be more spontaneous and can emit light or heat, resulting in runaway feedback(i.e. explosions).
values are also featured in particle physics. For example, |
https://en.wikipedia.org/wiki/Variational%20methods%20in%20general%20relativity | Variational methods in general relativity refers to various mathematical techniques that employ the use of variational calculus in Einstein's theory of general relativity. The most commonly used tools are Lagrangians and Hamiltonians and are used to derive the Einstein field equations.
Lagrangian methods
The equations of motion in physical theories can often be derived from an object called the Lagrangian. In classical mechanics, this object is usually of the form, 'kinetic energy − potential energy'. In general, the Lagrangian is that function which when integrated over produces the Action functional.
David Hilbert gave an early and classic formulation of the equations in Einstein's general relativity. This used the functional now called the Einstein-Hilbert action.
See also
Palatini action
Plebanski action
MacDowell–Mansouri action
Freidel–Starodubtsev action
Mathematics of general relativity
Fermat's and energy variation principles in field theory |
https://en.wikipedia.org/wiki/Cooling%20curve | A cooling curve is a line graph that represents the change of phase of matter, typically from a gas to a solid or a liquid to a solid. The independent variable (X-axis) is time and the dependent variable (Y-axis) is temperature. Below is an example of a cooling curve used in castings.
The initial point of the graph is the starting temperature of the matter, here noted as the "pouring temperature". When the phase change occurs, there is a "thermal arrest"; that is, the temperature stays constant. This is because the matter has more internal energy as a liquid or gas than in the state that it is cooling to. The amount of energy required for a phase change is known as latent heat. The "cooling rate" is the slope of the cooling curve at any point.
Alloy have range of melting point. It solidifies as above. First, molten alloy reaches to liquidus temperature and then freezing range starts. At solidus temperature, molten alloys becomes solid. |
https://en.wikipedia.org/wiki/Louisa%20Gross%20Horwitz%20Prize | The Louisa Gross Horwitz Prize for Biology or Biochemistry is an annual prize awarded by Columbia University to a researcher or group of researchers who have made an outstanding contribution in basic research in the fields of biology or biochemistry.
The prize was established at the bequest of S. Gross Horwitz and is named to honor his mother, Louisa Gross Horwitz, the daughter of trauma surgeon Samuel D. Gross. The prize was first awarded in 1967.
As of October 2018, 51 (50%) of the 101 prize recipients have subsequently been awarded the Nobel Prize in Physiology or Medicine (40) or Chemistry (11). It is regarded as one of the important precursors of a future Nobel Prize award.
Recipients
1967 Luis Leloir (1970 Chemistry)
1968 Har Gobind Khorana (1968 Physiology or Medicine), Marshall Warren Nirenberg (1968 Physiology or Medicine)
1969 Max Delbrück (1969 Physiology or Medicine), Salvador E. Luria (1969 Physiology or Medicine)
1970 Albert Claude (1974 Physiology or Medicine), George E. Palade (1974 Physiology or Medicine), Keith R. Porter
1971 Hugh E. Huxley
1972 Stephen W. Kuffler
1973 Renato Dulbecco (1975 Physiology or Medicine), Harry Eagle, Theodore T. Puck
1974 Boris Ephrussi
1975 K. Sune D. Bergstrom (1982 Physiology or Medicine), Bengt Samuelsson (1982 Physiology or Medicine)
1976 Seymour Benzer, Charles Yanofsky
1977 Michael Heidelberger, Elvin A. Kabat, Henry G. Kunkel
1978 David Hubel (1981 Physiology of Medicine), Vernon Mountcastle, Torsten Wiesel (1981 Physiology or Medicine)
1979 Walter Gilbert (1980 Chemistry), Frederick Sanger (1980 Chemistry)
1980 César Milstein (1984 Physiology or Medicine)
1981 Aaron Klug (1982 Chemistry)
1982 Barbara McClintock (1983 Physiology or Medicine), Susumu Tonegawa (1987 Physiology or Medicine)
1983 Stanley Cohen (1986 Physiology or Medicine), Viktor Hamburger, Rita Levi-Montalcini (1986 Physiology or Medicine)
1984 Michael S. Brown (1985 Physiology or Medicine), Joseph L. Goldstein (1985 Physiology or Medicine)
1985 |
https://en.wikipedia.org/wiki/Randall%20Division%20of%20Cell%20and%20Molecular%20Biophysics | The Randall Division of Cell and Molecular Biophysics (the Randall) is a research institute of King's College London located in London United Kingdom. It is a centre for study in allergy and asthma; muscle signalling and development; structural biology; muscle biophysics; cell motility and cytoskeleton, and cell imaging.
The Randall continues the tradition of Biophysics at King's established by Sir John Randall, which produced the studies of the structure of DNA by Rosalind Franklin and Maurice Wilkins. Much of this early work was supported by the Medical Research Council, who still provide the majority of research funding.
The Biophysics Unit expanded and in the 1960s moved to the site in Drury Lane that later became known as the Randall Institute, incorporating at various stages the King's Biophysics Department, MRC Cell Biophysics Unit, and MRC Muscle and Motility Unit. After King's merged with the Guy's and St Thomas’ Medical Schools in 1998, the Randall Institute research groups moved to new labs on the Guy's Campus at London Bridge, which became the present Randall Division of Cell and Molecular Biophysics. |
https://en.wikipedia.org/wiki/Jan%20Arnoldus%20Schouten | Jan Arnoldus Schouten (28 August 1883 – 20 January 1971) was a Dutch mathematician and Professor at the Delft University of Technology. He was an important contributor to the development of tensor calculus and Ricci calculus, and was one of the founders of the Mathematisch Centrum in Amsterdam.
Biography
Schouten was born in Nieuwer-Amstel to a family of eminent shipping magnates. He attended a Hogere Burger School, and later he took up studies in electrical engineering at the Delft Polytechnical School. After graduating in 1908, he worked for Siemens in Berlin and for a public utility in Rotterdam before returning to study mathematics in Delft in 1912. During his study he had become fascinated by the power and subtleties of vector analysis. After a short while in industry, he returned to Delft to study Mathematics, where he received his Ph.D. degree in 1914 under supervision of Jacob Cardinaal with a thesis entitled .
Schouten was an effective university administrator and leader of mathematical societies. During his tenure as professor and as institute head he was involved in various controversies with the topologist and intuitionist mathematician L. E. J. Brouwer. He was a shrewd investor as well as mathematician and successfully managed the budget of the institute and Dutch mathematical society. He hosted the International Congress of Mathematicians in Amsterdam in early 1954, and gave the opening address. Schouten was one of the founders of the Mathematisch Centrum in Amsterdam.
Among his PhD candidates students were Johanna Manders (1919), Dirk Struik (1922), Johannes Haantjes (1933), Wouter van der Kulk (1945), and Albert Nijenhuis (1952).
In 1933 Schouten became member of the Royal Netherlands Academy of Arts and Sciences.
Schouten died in 1971 in Epe. His son Jan Frederik Schouten (1910-1980) was Professor at the Eindhoven University of Technology from 1958 to 1978.
Work
Schouten's dissertation applied his "direct analysis", modeled on the vector ana |
https://en.wikipedia.org/wiki/Linklog | A linklog is a type of blog which is meant to act as a linked list. Common practice is for the post titles to link directly to an external URLs, and the content of the post includes information to complement the associated URL.
Linklogs existed as a feature of computing systems before the internet as well. In distributed file systems a link log was a method of recording data in which a record is created and added to the proper log when updating a transaction. The format of a log record closely matches the specification of the transaction type it corresponds to. Link log records consisted of two parts in such a system: a set of type-independent fields, and a set of type-specific fields. The former set consists of pointers to the preceding and succeeding records of the log.
In PBX systems such as AUDIX link-logs were a collection of data collecting to assist operators in maintaining the system.
Linklog software
Linkwalla - A lightweight link blogging engine
Delicious, a social bookmarking web service - Now Defunct
See also
Microblogging
External links
The Ruby and Rails community linklog
Tony Finch's linklog |
https://en.wikipedia.org/wiki/Geometry%20%26%20Topology | Geometry & Topology is a peer-refereed, international mathematics research journal devoted to geometry and topology, and their applications. It is currently based at the University of Warwick, United Kingdom, and published by Mathematical Sciences Publishers, a nonprofit academic publishing organisation.
It was founded in 1997 by a group of topologists who were dissatisfied with recent substantial rises in subscription prices of journals published by major publishing corporations. The aim was to set up a high-quality journal, capable of competing with existing journals, but with substantially lower subscription fees. The journal was open-access for its first ten years of existence and was available free to individual users, although institutions were required to pay modest subscription fees for both online access and for printed volumes. At present, an online subscription is required to view full-text PDF copies of articles in the most recent three volumes; articles older than that are open-access, at which point copies of the published articles are uploaded to the arXiv. A traditional printed version is also published, at present on an annual basis.
The journal has grown to be well respected in its field, and has in recent years published a number of important papers, in particular proofs of the Property P conjecture and the Birman conjecture. |
https://en.wikipedia.org/wiki/Fouling | Fouling is the accumulation of unwanted material on solid surfaces. The fouling materials can consist of either living organisms (biofouling) or a non-living substance (inorganic or organic). Fouling is usually distinguished from other surface-growth phenomena in that it occurs on a surface of a component, system, or plant performing a defined and useful function and that the fouling process impedes or interferes with this function.
Other terms used in the literature to describe fouling include deposit formation, encrustation, crudding, deposition, scaling, scale formation, slagging, and sludge formation. The last six terms have a more narrow meaning than fouling within the scope of the fouling science and technology, and they also have meanings outside of this scope; therefore, they should be used with caution.
Fouling phenomena are common and diverse, ranging from fouling of ship hulls, natural surfaces in the marine environment (marine fouling), fouling of heat-transfer components through ingredients contained in cooling water or gases, and even the development of plaque or calculus on teeth or deposits on solar panels on Mars, among other examples.
This article is primarily devoted to the fouling of industrial heat exchangers, although the same theory is generally applicable to other varieties of fouling. In cooling technology and other technical fields, a distinction is made between macro fouling and micro fouling. Of the two, micro fouling is the one that is usually more difficult to prevent and therefore more important.
Components subject to fouling
Examples of components that may be subject to fouling and the corresponding effects of fouling:
Heat exchanger surfaces – reduces thermal efficiency, decreases heat flux, increases temperature on the hot side, decreases temperature on the cold side, induces under-deposit corrosion, increases use of cooling water;
Piping, flow channels – reduces flow, increases pressure drop, increases upstream pressure, incr |
https://en.wikipedia.org/wiki/Myelin%20basic%20protein | Myelin basic protein (MBP) is a protein believed to be important in the process of myelination of nerves in the nervous system. The myelin sheath is a multi-layered membrane, unique to the nervous system, that functions as an insulator to greatly increase the velocity of axonal impulse conduction. MBP maintains the correct structure of myelin, interacting with the lipids in the myelin membrane.
MBP was initially sequenced in 1971 after isolation from bovine myelin membranes. MBP knockout mice called shiverer mice were subsequently developed and characterized in the early 1980s. Shiverer mice exhibit decreased amounts of CNS myelination and a progressive disorder characterized by tremors, seizures, and early death. The human gene for MBP is on chromosome 18; the protein localizes to the CNS and to various cells of the hematopoietic lineage.
The pool of MBP in the central nervous system is very diverse, with several splice variants being expressed and a large number of post-translational modifications on the protein, which include phosphorylation, methylation, deamidation, and citrullination. These forms differ by the presence or the absence of short (10 to 20 residues) peptides in various internal locations in the sequence. In general, the major form of MBP is a protein of about 18.5 Kd (170 residues).
In melanocytic cell types, MBP gene expression may be regulated by MITF.
Gene expression
The protein encoded by the classic MBP gene is a major constituent of the myelin sheath of oligodendrocytes and Schwann cells in the nervous system. However, MBP-related transcripts are also present in the bone marrow and the immune system. These mRNAs arise from the long MBP gene (otherwise called "Golli-MBP") that contains 3 additional exons located upstream of the classic MBP exons. Alternative splicing from the Golli and the MBP transcription start sites gives rise to 2 sets of MBP-related transcripts and gene products. The Golli mRNAs contain 3 exons unique to Golli-MBP |
https://en.wikipedia.org/wiki/Envelope%20%28motion%29 | In mechanical engineering, an envelope is a solid representing all positions which may be occupied by an object during its normal range of motion.
Another (jargon) word for this is a "flop".
Wheel envelope
In automobile design, a wheel envelope may be used to model all positions a wheel and tire combo may be expected to occupy during driving. This will take into account the maximum jounce and rebound allowed by the suspension system and the maximum turn and tilt allowed by the steering mechanism. Minimum and maximum tire inflation pressures and wear conditions may also be considered when generating the envelope.
This envelope is then compared with the wheel housing and other components in the area to perform an interference/collision analysis. The results of this analysis tell the engineers whether that wheel/tire combo will strike the housing and components under normal driving conditions. If so, either a redesign is in order, or that wheel/tire combo will not be recommended.
A different wheel envelope must be generated for each wheel/tire combo for which the vehicle is rated. Much of this analysis is done using CAD/CAE systems running on computers. Of course, high speed collisions, during an accident, are not considered "normal driving conditions", so the wheel and tire may very well contact other parts of the vehicle at that time.
Robot's working envelope
In robotics, the working envelope or work area is the volume of working or reaching space. Some factors of a robot's design (configurations, axes or degrees of freedom) influence its working envelope. |
https://en.wikipedia.org/wiki/List%20of%20rare%20species%20in%20the%20British%20National%20Vegetation%20Classification | The following is a list of vascular plants, bryophytes and lichens which were regarded as rare species by the authors of British Plant Communities, together with the communities in which they occur.
Vascular plants
Man orchid (Aceras anthropophorum) CG2, CG3, CG5
Baneberry (Actaea spicata) W9
Bristle bent (Agrostis curtisii) H2, H3, H4, H5, H6
Ground-pine (Ajuga chamaepitys) CG2, OV15
The lady's-mantle Alchemilla filicaulis ssp. filicaulis CG10
The lady's-mantle Alchemilla acutiloba MG3
The lady's-mantle Alchemilla glomerulans MG3
The lady's-mantle Alchemilla monticola MG3
The lady's-mantle Alchemilla subcrenata MG3
The lady's-mantle Alchemilla wichurae MG3, CG10
Babington's leek (Allium ampeloprasum var. babingtonii) OV6
Chives (Allium schoenoprasum) H6, H7, MC5
Three-cornered garlic (Allium triquetrum) OV24
Bog-rosemary (Andromeda polifolia) M2
Annual vernal-grass (Anthoxanthum aristatum) OV1
Loose silky-bent (Apera spica-venti) OV5
Bristol rock-cress (Arabis stricta) CG1
Field wormwood (Artemisia campestris) CG7
Goldilocks aster (Aster linosyris) CG1
Purple milk-vetch (Astragalus danicus) H7, CG2, CG3, CG4, CG5, CG7, SD11, SD12, MC10, MC5
Wild cabbage (Brassica oleracea) OV41, MC4, MC5
Lesser quaking-grass (Briza minor) OV1, OV2, OV6
Lesser hairy brome (Bromus benekenii) W9
Great pignut (Bunium bulbocastanum) CG2
Small hare's-ear (Bupleurum baldense) CG1
European box (Buxus sempervirens) W13
Narrow small-reed (Calamagrostis stricta) S1
Narrow-leaved bittercress (Cardamine impatiens) W8
Fibrous tussock-sedge (Carex appropinquata) W3
Hair sedge (Carex capillaris) CG10
String sedge (Carex chordorrhiza) M4
Lesser tussock-sedge (Carex diandra) W3
Elongated sedge (Carex elongata) W2
Rare spring-sedge (Carex ericetorum) CG2, CG5, CG7
Dwarf sedge (Carex humilis) CG1, CG2, CG3
Tall bog-sedge (Carex magellanica) M2
Soft-leaved sedge (Carex montana) H4, CG2, CG10
Rock sedge (Carex rupestris) CG10
Common centaury (Centaurium ery |
https://en.wikipedia.org/wiki/Trembling%20hand%20perfect%20equilibrium | In game theory, trembling hand perfect equilibrium is a type of refinement of a Nash equilibrium that was first proposed by Reinhard Selten. A trembling hand perfect equilibrium is an equilibrium that takes the possibility of off-the-equilibrium play into account by assuming that the players, through a "slip of the hand" or tremble, may choose unintended strategies, albeit with negligible probability.
Definition
First define a perturbed game. A perturbed game is a copy of a base game, with the restriction that only totally mixed strategies are allowed to be played.
A totally mixed strategy is a mixed strategy where every strategy (both pure and mixed) is played with non-zero probability.
This is the "trembling hands" of the players; they sometimes play a different strategy, other than the one they intended to play. Then define a strategy set S (in a base game) as being trembling hand perfect if there is a sequence of perturbed games that converge to the base game in which there is a series of Nash equilibria that converge to S.
Note: All completely mixed Nash equilibria are perfect.
Note 2: The mixed strategy extension of any finite normal-form game has at least one perfect equilibrium.
Example
The game represented in the following normal form matrix has two pure strategy Nash equilibria, namely and . However, only is trembling-hand perfect.
Assume player 1 (the row player) is playing a mixed strategy , for .
Player 2's expected payoff from playing L is:
Player 2's expected payoff from playing the strategy R is:
For small values of , player 2 maximizes his expected payoff by placing a minimal weight on R and maximal weight on L. By symmetry, player 1 should place a minimal weight on D and maximal weight on U if player 2 is playing the mixed strategy . Hence is trembling-hand perfect.
However, similar analysis fails for the strategy profile .
Assume player 2 is playing a mixed strategy . Player 1's expected payoff from playing U is:
Player 1's |
https://en.wikipedia.org/wiki/The%20Practice%20of%20Programming | The Practice of Programming () by Brian W. Kernighan and Rob Pike is a 1999 book about computer programming and software engineering, published by Addison-Wesley.
According to the preface, the book is about "topics like testing, debugging, portability, performance, design alternatives, and style", which, according to the authors, "are not usually the focus of computer science or programming courses". It treats these topics in case studies, featuring implementations in several programming languages (mostly C, but also C++, AWK, Perl, Tcl and Java).
The Practice of Programming has been translated into twelve languages. Eric S. Raymond, in The Art of Unix Programming, calls it "recommended reading for all C programmers (indeed for all programmers in any language)". A 2008 review on LWN.net found that TPOP "has aged well due to its focus on general principles" and that "beginners will benefit most but experienced developers will appreciate [...] the later chapters". |
https://en.wikipedia.org/wiki/Assembly%20modelling | Assembly modeling is a technology and method used by computer-aided design and product visualization computer software systems to handle multiple files that represent components within a product. The components within an assembly are represented as solid or surface models.
Overview
The designer generally has access to models that others are working on concurrently. For example, several people may be designing one machine that has many parts. New parts are added to an assembly model as they are created. Each designer has access to the assembly model, while a work in progress, and while working in their own parts. The design evolution is visible to everyone involved. Depending on the system, it might be necessary for the users to acquire the latest versions saved of each individual components to update the assembly.
The individual data files describing the 3D geometry of individual components are assembled together through a number of sub-assembly levels to create an assembly describing the whole product. All CAD and CPD systems support this form of bottom-up construction. Some systems, via associative copying of geometry between components also allow top-down method of design.
Components can be positioned within the product assembly using absolute coordinate placement methods or by means of mating conditions. Mating conditions are definitions of the relative position of components between each other; for example alignment of axis of two holes or distance of two faces from one another. The final position of all components based on these relationships is calculated using a geometry constraint engine built into the CAD or visualization package.
The importance of assembly modeling in achieving the full benefits of PLM has led to ongoing advances in this technology. These include the use of lightweight data structures such as JT that allow visualization of and interaction with large amounts of product data, direct interface to between Digital Mock ups and PDM systems |
https://en.wikipedia.org/wiki/List%20of%20constant%20species%20in%20the%20British%20National%20Vegetation%20Classification | The following is a list of vascular plants, bryophytes and lichens which are constant species in one or more community of the British National Vegetation Classification system.
Vascular plants
Grasses
Sedges and rushes
Trees
Other dicotyledons
Other monocotyledons
Ferns
Clubmosses
Bryophytes
Mosses
Liverworts
Lichens
British National Vegetation Classification
Lists of biota of the United Kingdom
British National Vegetation Classification, constant |
https://en.wikipedia.org/wiki/Oblique%20reflection | In Euclidean geometry, oblique reflections generalize ordinary reflections by not requiring that reflection be done using perpendiculars. If two points are oblique reflections of each other, they will still stay so under affine transformations.
Consider a plane P in the three-dimensional Euclidean space. The usual reflection of a point A in space in respect to the plane P is another point B in space, such that the midpoint of the segment AB is in the plane, and AB is perpendicular to the plane. For an oblique reflection, one requires instead of perpendicularity that AB be parallel to a given reference line.
Formally, let there be a plane P in the three-dimensional space, and a line L in space not parallel to P. To obtain the oblique reflection of a point A in space in respect to the plane P, one draws through A a line parallel to L, and lets the oblique reflection of A be the point B on that line on the other side of the plane such that the midpoint of AB is in P. If the reference line L is perpendicular to the plane, one obtains the usual reflection.
For example, consider the plane P to be the xy plane, that is, the plane given by the equation z=0 in Cartesian coordinates. Let the direction of the reference line L be given by the vector (a, b, c), with c≠0 (that is, L is not parallel to P). The oblique reflection of a point (x, y, z) will then be
The concept of oblique reflection is easily generalizable to oblique reflection in respect to an affine hyperplane in Rn with a line again serving as a reference, or even more generally, oblique reflection in respect to a k-dimensional affine subspace, with a n−k-dimensional affine subspace serving as a reference. Back to three dimensions, one can then define oblique reflection in respect to a line, with a plane serving as a reference.
An oblique reflection is an affine transformation, and it is an involution, meaning that the reflection of the reflection of a point is the point itself. |
https://en.wikipedia.org/wiki/Pertussis%20toxin | Pertussis toxin (PT) is a protein-based AB5-type exotoxin produced by the bacterium Bordetella pertussis, which causes whooping cough. PT is involved in the colonization of the respiratory tract and the establishment of infection. Research suggests PT may have a therapeutic role in treating a number of common human ailments, including hypertension, viral infection, and autoimmunity.
History
PT clearly plays a central role in the pathogenesis of pertussis although this was discovered only in the early 1980s. The appearance of pertussis is quite recent, compared with other epidemic infectious diseases. The earliest mention of pertussis, or whooping cough, is of an outbreak in Paris in 1414. This was published in Moulton's The Mirror of Health, in 1640. Another epidemic of pertussis took place in Paris in 1578 and was described by a contemporary observer, Guillaume de Baillou. Pertussis was well known throughout Europe by the middle of the 18th century. Jules Bordet and Octave Gengou described in 1900 the finding of a new “ovoid bacillus” in the sputum of a 6-month-old infant with whooping cough. They were also the first to cultivate Bordetella pertussis at the Pasteur Institute in Brussels in 1906.
One difference between the different species of Bordetella is that B. pertussis produces PT and the other species do not. Bordetella parapertussis shows the most similarity to B. pertussis and was therefore used for research determining the role of PT in causing the typical symptoms of whooping cough. Rat studies showed the development of paroxysmal coughing, a characteristic for whooping cough, occurred in rats infected with B. pertussis. Rats infected with B. parapertussis or a PT-deficient mutant of B. pertussis did not show this symptom; neither of these two strains produced PT.
Structure
A large group of bacterial exotoxins are referred to as "A/B toxins", in essence because they are formed from two subunits. The "A" subunit possesses enzyme activity, and is transf |
https://en.wikipedia.org/wiki/Trihexagonal%20tiling | In geometry, the trihexagonal tiling is one of 11 uniform tilings of the Euclidean plane by regular polygons. It consists of equilateral triangles and regular hexagons, arranged so that each hexagon is surrounded by triangles and vice versa. The name derives from the fact that it combines a regular hexagonal tiling and a regular triangular tiling. Two hexagons and two triangles alternate around each vertex, and its edges form an infinite arrangement of lines. Its dual is the rhombille tiling.
This pattern, and its place in the classification of uniform tilings, was already known to Johannes Kepler in his 1619 book Harmonices Mundi. The pattern has long been used in Japanese basketry, where it is called kagome. The Japanese term for this pattern has been taken up in physics, where it is called a kagome lattice. It occurs also in the crystal structures of certain minerals. Conway calls it a hexadeltille, combining alternate elements from a hexagonal tiling (hextille) and triangular tiling (deltille).
Kagome
Kagome () is a traditional Japanese woven bamboo pattern; its name is composed from the words kago, meaning "basket", and me, meaning "eye(s)", referring to the pattern of holes in a woven basket.
The kagome pattern is common in bamboo weaving in East Asia. In 2022, archaeologists found bamboo weaving remains at the Dongsunba ruins in Chongqing, China, 200 BC. After 2200 years, the kagome pattern is still clear.
It is a woven arrangement of laths composed of interlaced triangles such that each point where two laths cross has four neighboring points, forming the pattern of a trihexagonal tiling. The woven process gives the Kagome a chiral wallpaper group symmetry, p6, (632).
Kagome lattice
The term kagome lattice was coined by Japanese physicist Kôdi Husimi, and first appeared in a 1951 paper by his assistant Ichirō Shōji.
The kagome lattice in this sense consists of the vertices and edges of the trihexagonal tiling.
Despite the name, these crossing points do |
https://en.wikipedia.org/wiki/Calpain | A calpain (; , ) is a protein belonging to the family of calcium-dependent, non-lysosomal cysteine proteases (proteolytic enzymes) expressed ubiquitously in mammals and many other organisms. Calpains constitute the C2 family of protease clan CA in the MEROPS database. The calpain proteolytic system includes the calpain proteases, the small regulatory subunit CAPNS1, also known as CAPN4, and the endogenous calpain-specific inhibitor, calpastatin.
Discovery
The history of calpain's discovery originates in 1964, when calcium-dependent proteolytic activities caused by a "calcium-activated neutral protease" (CANP) were detected in brain, lens of the eye and other tissues. In the late 1960s the enzymes were isolated and characterised independently in both rat brain and skeletal muscle. These activities were caused by an intracellular cysteine protease not associated with the lysosome and having an optimum activity at neutral pH, which clearly distinguished it from the cathepsin family of proteases. The calcium-dependent activity, intracellular localization, and the limited, specific proteolysis on its substrates, highlighted calpain’s role as a regulatory, rather than a digestive, protease. When the sequence of this enzyme became known, it was given the name "calpain", to recognize its common properties with two well-known proteins at the time, the calcium-regulated signalling protein, calmodulin, and the cysteine protease of papaya, papain. Shortly thereafter, the activity was found to be attributable to two main isoforms, dubbed μ ("mu")-calpain and m-calpain (or calpain I and II), that differed primarily in their calcium requirements in vitro. Their names reflect the fact that they are activated by micro- and nearly millimolar concentrations of Ca2+ within the cell, respectively.
To date, these two isoforms remain the best characterised members of the calpain family. Structurally, these two heterodimeric isoforms share an identical small (28 kDa) subunit (CAPNS1 (f |
https://en.wikipedia.org/wiki/Inward-rectifier%20potassium%20channel | Inward-rectifier potassium channels (Kir, IRK) are a specific lipid-gated subset of potassium channels. To date, seven subfamilies have been identified in various mammalian cell types, plants, and bacteria. They are activated by phosphatidylinositol 4,5-bisphosphate (PIP2). The malfunction of the channels has been implicated in several diseases. IRK channels possess a pore domain, homologous to that of voltage-gated ion channels, and flanking transmembrane segments (TMSs). They may exist in the membrane as homo- or heterooligomers and each monomer possesses between 2 and 4 TMSs. In terms of function, these proteins transport potassium (K+), with a greater tendency for K+ uptake than K+ export. The process of inward-rectification was discovered by Denis Noble in cardiac muscle cells in 1960s and by Richard Adrian and Alan Hodgkin in 1970 in skeletal muscle cells.
Overview of inward rectification
A channel that is "inwardly-rectifying" is one that passes current (positive charge) more easily in the inward direction (into the cell) than in the outward direction (out of the cell). It is thought that this current may play an important role in regulating neuronal activity, by helping to stabilize the resting membrane potential of the cell.
By convention, inward current (positive charge moving into the cell) is displayed in voltage clamp as a downward deflection, while an outward current (positive charge moving out of the cell) is shown as an upward deflection. At membrane potentials negative to potassium's reversal potential, inwardly rectifying K+ channels support the flow of positively charged K+ ions into the cell, pushing the membrane potential back to the resting potential. This can be seen in figure 1: when the membrane potential is clamped negative to the channel's resting potential (e.g. -60 mV), inward current flows (i.e. positive charge flows into the cell). However, when the membrane potential is set positive to the channel's resting potential (e.g. +60 mV), |
https://en.wikipedia.org/wiki/Minichamps | Minichamps is a die-cast model car brand founded as Paul's Model Art GmbH in 1990 in Aachen, Germany, best known for its 1:18, 1:43 and 1:64 scale models. The company grew out of the Danhausen trade catalog of miniature vehicles and specially made Danhausen diecast releases during the 1970s.
The Danhausen legacy
Danhausen was a trade company established in 1921 which sold a variety of products like bicycles and motorscooters. As time passed it focused more on toys and by 1971 the company was owned by the Grandsons of Emma Danhausen, Hans Peter and Paul Gunter Lang. At this time the Lang brothers moved into selling model cars both over-the-counter and by mail order. The brothers distributed many different marques of mainly 1:43 scale models and began to publish the famous Danhausen World Model Car Book annually from 1971 to 1993, which was the last word in available 1:43 scale models worldwide. The last edition of the catalog in 1993 was 350 pages long and listed 15,000 models.
During the mid-1970s, the Langs contracted with several companies, including Tin Wizard, Western Models and AMR (André Marie Ruf) as suppliers of the models they desired. These were almost exclusively made in white metal and the cars provided were given several different names; one was 'SD Modelle', another 'Metal 43', 'Plumbies' and 'Plumbies Inter'. Yet another was to go on to become the permanent name for the company – Minichamps by Danhausen, at first mainly a range of racing cars. Reportedly, the first model offered to Danhausen by Western Models was a Mercedes-Benz 540K. Though using other companies' miniatures, Danhausen became a model name unto itself and as time passed the brothers tried to cement the relationship as Western Models had supplied Danhausen for about a decade. The Langs wanted to buy Western Models, but owner Mike Stephens declined. Eventually they purchased AMR and Danhausen was finally a de facto producer.
During the 1980s, Danhausen moved into HO scale, producing m |
https://en.wikipedia.org/wiki/Majorization | In mathematics, majorization is a preorder on vectors of real numbers. Let denote the -th largest element of the vector . Given , we say that weakly majorizes (or dominates) from below (or equivalently, we say that is weakly majorized (or dominated) by from below) denoted as if for all . If in addition , we say that majorizes (or dominates) , written as , or equivalently, we say that is majorized (or dominated) by . The order of the entries of the vectors or does not affect the majorization, e.g., the statement is simply equivalent to . As a consequence, majorization is not a partial order, since and do not imply , it only implies that the components of each vector are equal, but not necessarily in the same order.
The majorization partial order on finite dimensional vectors, described here, can be generalized to the Lorenz ordering, a partial order on distribution functions. For example, a wealth distribution is Lorenz-greater than another if its Lorenz curve lies below the other. As such, a Lorenz-greater wealth distribution has a higher Gini coefficient, and has more income disparity. Various other generalizations of majorization are discussed in chapters 14 and 15 of.
The majorization preorder can be naturally extended to density matrices in the context of quantum information. In particular, exactly when (where denotes the state's spectrum).
Examples
(Strong) majorization: . For vectors with components
(Weak) majorization: . For vectors with components:
Geometry of majorization
For we have if and only if is in the convex hull of all vectors obtained by permuting the coordinates of .
Figure 1 displays the convex hull in 2D for the vector . Notice that the center of the convex hull, which is an interval in this case, is the vector . This is the "smallest" vector satisfying for this given vector .
Figure 2 shows the convex hull in 3D. The center of the convex hull, which is a 2D polygon in this case, is the "smallest" vector satisfy |
https://en.wikipedia.org/wiki/String%20cosmology | String cosmology is a relatively new field that tries to apply equations of string theory to solve the questions of early cosmology. A related area of study is brane cosmology.
Overview
This approach can be dated back to a paper by Gabriele Veneziano that shows how an inflationary cosmological model can be obtained from string theory, thus opening the door to a description of pre-Big Bang scenarios.
The idea is related to a property of the bosonic string in a curve background, better known as nonlinear sigma model. First calculations from this model showed as the beta function, representing the running of the metric of the model as a function of an energy scale, is proportional to the Ricci tensor giving rise to a Ricci flow. As this model has conformal invariance and this must be kept to have a sensible quantum field theory, the beta function must be zero producing immediately the Einstein field equations. While Einstein equations seem to appear somewhat out of place, nevertheless this result is surely striking showing as a background two-dimensional model could produce higher-dimensional physics. An interesting point here is that such a string theory can be formulated without a requirement of criticality at 26 dimensions for consistency as happens on a flat background. This is a serious hint that the underlying physics of Einstein equations could be described by an effective two-dimensional conformal field theory. Indeed, the fact that we have evidence for an inflationary universe is an important support to string cosmology.
In the evolution of the universe, after the inflationary phase, the expansion observed today sets in that is well described by Friedmann equations. A smooth transition is expected between these two different phases. String cosmology appears to have difficulties in explaining this transition. This is known in the literature as the graceful exit problem.
An inflationary cosmology implies the presence of a scalar field that drives inflation. |
https://en.wikipedia.org/wiki/Fermi%E2%80%93Pasta%E2%80%93Ulam%E2%80%93Tsingou%20problem | In physics, the Fermi–Pasta–Ulam–Tsingou (FPUT) problem or formerly the Fermi–Pasta–Ulam problem was the apparent paradox in chaos theory that many complicated enough physical systems exhibited almost exactly periodic behavior – called Fermi–Pasta–Ulam–Tsingou recurrence (or Fermi–Pasta–Ulam recurrence) – instead of the expected ergodic behavior. This came as a surprise, as Enrico Fermi, certainly, expected the system to thermalize in a fairly short time. That is, it was expected for all vibrational modes to eventually appear with equal strength, as per the equipartition theorem, or, more generally, the ergodic hypothesis. Yet here was a system that appeared to evade the ergodic hypothesis. Although the recurrence is easily observed, it eventually became apparent that over much, much longer time periods, the system does eventually thermalize. Multiple competing theories have been proposed to explain the behavior of the system, and it remains a topic of active research.
The original intent was to find a physics problem worthy of numerical simulation on the then-new MANIAC computer. Fermi felt that thermalization would pose such a challenge. As such, it represents one of the earliest uses of digital computers in mathematical research; simultaneously, the unexpected results launched the study of nonlinear systems.
The FPUT experiment
In the summer of 1953 Enrico Fermi, John Pasta, Stanislaw Ulam, and Mary Tsingou conducted computer simulations of a vibrating string that included a non-linear term (quadratic in one test, cubic in another, and a piecewise linear approximation to a cubic in a third). They found that the behavior of the system was quite different from what intuition would have led them to expect. Enrico Fermi thought that after many iterations, the system would exhibit thermalization, an ergodic behavior in which the influence of the initial modes of vibration fade and the system becomes more or less random with all modes excited more or less equally. |
https://en.wikipedia.org/wiki/Schr%C3%B6dinger%20functional | In mathematical physics, some approaches to quantum field theory are more popular than others. For historical reasons, the Schrödinger representation is less favored than Fock space methods. In the early days of quantum field theory, maintaining symmetries such as Lorentz invariance, displaying them manifestly, and proving renormalisation were of paramount importance. The Schrödinger representation is not manifestly Lorentz invariant and its renormalisability was only shown as recently as the 1980s by Kurt Symanzik (1981).
The Schrödinger functional is, in its most basic form, the time translation generator of state wavefunctionals. In layman's terms, it defines how a system of quantum particles evolves through time and what the subsequent systems look like.
Background
Quantum mechanics is defined over the spatial coordinates upon which the Galilean group acts, and the corresponding operators act on its state as . The state is characterized by a wave function obtained by projecting it onto the coordinate eigenstates defined by . These eigenstates are not stationary. Time evolution is generated by the Hamiltonian, yielding the Schrödinger equation .
However, in quantum field theory, the coordinate is the field operator , which acts on the state's wave functional as
where "" indicates an unbound spatial argument. This wave functional
is obtained by means of the field eigenstates
which are indexed by unapplied "classical field" configurations . These eigenstates, like the position eigenstates above, are not stationary. Time evolution is generated by the Hamiltonian, yielding the Schrödinger equation,
Thus the state in quantum field theory is conceptually a functional superposition of field configurations.
Example: scalar field
In the quantum field theory of (as example) a quantum scalar field , in complete analogy with the one-particle quantum harmonic oscillator, the eigenstate of this quantum field with the "classical field" (c-number) as its eigen |
https://en.wikipedia.org/wiki/Staggered%20fermion | In lattice field theory, staggered fermions (also known as Kogut–Susskind fermions) are a fermion discretization that reduces the number of fermion doublers from sixteen to four. They are one of the fastest lattice fermions when it comes to simulations and they also possess some nice features such as a remnant chiral symmetry, making them very popular in lattice QCD calculations. Staggered fermions were first formulated by John Kogut and Leonard Susskind in 1975 and were later found to be equivalent to the discretized version of the Dirac–Kähler fermion.
Constructing staggered fermions
Single-component basis
The naively discretized Dirac action in Euclidean spacetime with lattice spacing and Dirac fields at every lattice point, indexed by , takes the form
Staggered fermions are constructed from this by performing the staggered transformation into a new basis of fields defined by
Since Dirac matrices square to the identity, this position dependent transformation mixes the fermion spin components in a way that repeats itself every two lattice spacings. Its effect is to diagonalize the action in the spinor indices, meaning that the action ends up splitting into four distinct parts, one for each Dirac spinor component. Denoting one of those components by , which is Grassmann variable with no spin structure, the other three components can be dropped, yielding the single-component staggered action
where are unit vectors in the direction and the staggered sign function is given by . The staggered transformation is part of a larger class of transformations satisfying . Together with a necessary consistency condition on the plaquettes, all these transformations are equivalent to the staggered transformation. Due to fermion doubling, the original naive action described sixteen fermions, but having discarded three of the four copies this new action describes only four.
Spin-taste basis
To explicitly show that the single-component staggered fermion action descri |
https://en.wikipedia.org/wiki/Hamiltonian%20lattice%20gauge%20theory | In physics, Hamiltonian lattice gauge theory is a calculational approach to gauge theory and a special case of lattice gauge theory in which the space is discretized but time is not. The Hamiltonian is then re-expressed as a function of degrees of freedom defined on a d-dimensional lattice.
Following Wilson, the spatial components of the vector potential are replaced with Wilson lines over the edges, but the time component is associated with the vertices. However, the temporal gauge is often employed, setting the electric potential to zero. The eigenvalues of the Wilson line operators U(e) (where e is the (oriented) edge in question) take on values on the Lie group G. It is assumed that G is compact, otherwise we run into many problems. The conjugate operator to U(e) is the electric field E(e) whose eigenvalues take on values in the Lie algebra . The Hamiltonian receives contributions coming from the plaquettes (the magnetic contribution) and contributions coming from the edges (the electric contribution).
Hamiltonian lattice gauge theory is exactly dual to a theory of spin networks. This involves using the Peter–Weyl theorem. In the spin network basis, the spin network states are eigenstates of the operator . |
https://en.wikipedia.org/wiki/Linearized%20gravity | In the theory of general relativity, linearized gravity is the application of perturbation theory to the metric tensor that describes the geometry of spacetime. As a consequence, linearized gravity is an effective method for modeling the effects of gravity when the gravitational field is weak. The usage of linearized gravity is integral to the study of gravitational waves and weak-field gravitational lensing.
Weak-field approximation
The Einstein field equation (EFE) describing the geometry of spacetime is given as (using natural units)
where is the Ricci tensor, is the Ricci scalar, is the energy–momentum tensor, and is the spacetime metric tensor that represent the solutions of the equation.
Although succinct when written out using Einstein notation, hidden within the Ricci tensor and Ricci scalar are exceptionally nonlinear dependencies on the metric which render the prospect of finding exact solutions impractical in most systems. However, when describing particular systems for which the curvature of spacetime is small (meaning that terms in the EFE that are quadratic in do not significantly contribute to the equations of motion), one can model the solution of the field equations as being the Minkowski metric plus a small perturbation term . In other words:
In this regime, substituting the general metric for this perturbative approximation results in a simplified expression for the Ricci tensor:
where is the trace of the perturbation, denotes the partial derivative with respect to the coordinate of spacetime, and is the d'Alembert operator.
Together with the Ricci scalar,
the left side of the field equation reduces to
and thus the EFE is reduced to a linear, second order partial differential equation in terms of .
Gauge invariance
The process of decomposing the general spacetime into the Minkowski metric plus a perturbation term is not unique. This is due to the fact that different choices for coordinates may give different forms for . In ord |
https://en.wikipedia.org/wiki/Fusion%20rules | In mathematics and theoretical physics, fusion rules are rules that determine the exact decomposition of the tensor product of two representations of a group into a direct sum of irreducible representations. The term is often used in the context of two-dimensional conformal field theory where the relevant group is generated by the Virasoro algebra, the relevant representations are the conformal families associated with a primary field and the tensor product is realized by operator product expansions. The fusion rules contain the information about the kind of families that appear on the right hand side of these OPEs, including the multiplicities.
More generally, integrable models in 2 dimensions which aren't conformal field theories are also described by fusion rules for their charges. |
https://en.wikipedia.org/wiki/Conformal%20family | In theoretical physics, a conformal family is an irreducible representation of the Virasoro algebra. In most cases, it is uniquely determined by its primary field or the highest weight vector. The family contains all of its descendant fields. |
https://en.wikipedia.org/wiki/Ischemic%20cascade | The ischemic (ischaemic) cascade is a series of biochemical reactions that are initiated in the brain and other aerobic tissues after seconds to minutes of ischemia (inadequate blood supply). This is typically secondary to stroke, injury, or cardiac arrest due to heart attack. Most ischemic neurons that die do so due to the activation of chemicals produced during and after ischemia. The ischemic cascade usually goes on for two to three hours but can last for days, even after normal blood flow returns.
Mechanism
A cascade is a series of events in which one event triggers the next, in a linear fashion. Thus "ischemic cascade" is actually a misnomer, since the events are not always linear: in some cases they are circular, and sometimes one event can cause or be caused by multiple events. In addition, cells receiving different amounts of blood may go through different chemical processes. Despite these facts, the ischemic cascade can be generally characterized as follows:
Lack of oxygen causes the neuron's normal process for making ATP for energy to fail.
The cell switches to anaerobic metabolism, producing lactic acid.
ATP-reliant ion transport pumps fail, causing the cell to become depolarized, allowing ions, including calcium (Ca2+), to flow into the cell.
The ion pumps can no longer transport calcium out of the cell, and intracellular calcium levels get too high.
The presence of calcium triggers the release of the excitatory amino acid neurotransmitter glutamate.
Glutamate stimulates AMPA receptors and Ca2+-permeable NMDA receptors, which open to allow more calcium into cells.
Excess calcium entry overexcites cells and causes the generation of harmful chemicals like free radicals, reactive oxygen species and calcium-dependent enzymes such as calpain, endonucleases, ATPases, and phospholipases in a process called excitotoxicity. Calcium can also cause the release of more glutamate.
As the cell's membrane is broken down by phospholipases, it becomes more per |
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