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https://en.wikipedia.org/wiki/Read%E2%80%93write%20memory
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Read–write memory, or RWM is a type of computer memory that can be easily written to as well as read from using electrical signaling normally associated with running a software, and without any other physical processes. The related storage type RAM means something different; it refers to memory that can access any memory location in a constant amount of time.
The term might also refer to memory locations having both read and write permissions. In modern computer systems using memory segmentation, each segment has a length and set of permissions associated with it.
Types
Read–write memory is composed of either volatile or non-volatile types of storage. Volatile memory is usually in the form of a microchip or other hardware that requires an external power source to enable data to persist. Non-volatile memory is considered static, or storage-type memory. This means that you can write data to it, and that information will persist even in the absence of a power source. Typically read-write speeds are limited to its bandwidth or have mechanical limitations of either rotation speeds and arm movement delays for storage types such as Cloud Storage, Hard Disk Drive or CD-RWs, DVD-RWs, SD cards, Solid State Drive, SRAM, and DRAM, or other integrated circuitry.
History
San Francisco in 1956, IBM was the first company to develop and sell the first commercial Hard Disk Drive (HDD). The drive was the Model 350 disk storage unit, which was 3.75 Megabytes of data storage capacity and had fifty 24-inch diameter disks stacked on a spindle and sold to Zellerbach paper.
See also
Read-mostly memory (RMM)
Random-access memory (RAM)
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https://en.wikipedia.org/wiki/Boolean%20model%20of%20information%20retrieval
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The (standard) Boolean model of information retrieval (BIR) is a classical information retrieval (IR) model and, at the same time, the first and most-adopted one. It is used by many IR systems to this day. The BIR is based on Boolean logic and classical set theory in that both the documents to be searched and the user's query are conceived as sets of terms (a bag-of-words model). Retrieval is based on whether or not the documents contain the query terms.
Definitions
An index term is a word or expression, which may be stemmed, describing or characterizing a document, such as a keyword given for a journal article. Letbe the set of all such index terms.
A document is any subset of . Letbe the set of all documents.
A query is a Boolean expression in normal form:where is true for when . (Equivalently, could be expressed in disjunctive normal form.)
We seek to find the set of documents that satisfy . This operation is called retrieval and consists of the following two steps:
1. For each in , find the set of documents that satisfy :2. Then the set of documents that satisfy Q is given by:
Example
Let the set of original (real) documents be, for example
where
= "Bayes' principle: The principle that, in estimating a parameter, one should initially assume that each possible value has equal probability (a uniform prior distribution)."
= "Bayesian decision theory: A mathematical theory of decision-making which presumes utility and probability functions, and according to which the act to be chosen is the Bayes act, i.e. the one with highest subjective expected utility. If one had unlimited time and calculating power with which to make every decision, this procedure would be the best way to make any decision."
= "Bayesian epistemology: A philosophical theory which holds that the epistemic status of a proposition (i.e. how well proven or well established it is) is best measured by a probability and that the proper way to revise this probability is given
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https://en.wikipedia.org/wiki/ITIL%20security%20management
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ITIL security management describes the structured fitting of security into an organization. ITIL security management is based on the ISO 27001 standard. "ISO/IEC 27001:2005 covers all types of organizations (e.g. commercial enterprises, government agencies, not-for profit organizations). ISO/IEC 27001:2005 specifies the requirements for establishing, implementing, operating, monitoring, reviewing, maintaining and improving a documented Information Security Management System within the context of the organization's overall business risks. It specifies requirements for the implementation of security controls customized to the needs of individual organizations or parts thereof. ISO/IEC 27001:2005 is designed to ensure the selection of adequate and proportionate security controls that protect information assets and give confidence to interested parties."
A basic concept of security management is information security. The primary goal of information security is to control access to information. The value of the information is what must be protected. These values include confidentiality, integrity and availability. Inferred aspects are privacy, anonymity and verifiability.
The goal of security management comes in two parts:
Security requirements defined in service level agreements (SLA) and other external requirements that are specified in underpinning contracts, legislation and possible internal or external imposed policies.
Basic security that guarantees management continuity. This is necessary to achieve simplified service-level management for information security.
SLAs define security requirements, along with legislation (if applicable) and other contracts. These requirements can act as key performance indicators (KPIs) that can be used for process management and for interpreting the results of the security management process.
The security management process relates to other ITIL-processes. However, in this particular section the most obvious relations are the
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https://en.wikipedia.org/wiki/Soil%20seed%20bank
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The soil seed bank is the natural storage of seeds, often dormant, within the soil of most ecosystems. The study of soil seed banks started in 1859 when Charles Darwin observed the emergence of seedlings using soil samples from the bottom of a lake. The first scientific paper on the subject was published in 1882 and reported on the occurrence of seeds at different soil depths. Weed seed banks have been studied intensely in agricultural science because of their important economic impacts; other fields interested in soil seed banks include forest regeneration and restoration ecology.
Henry David Thoreau wrote that the contemporary popular belief explaining the succession of a logged forest, specifically to trees of a dissimilar species to the trees cut down, was that seeds either spontaneously generated in the soil, or sprouted after lying dormant for centuries. However, he dismissed this idea, noting that heavy nuts unsuited for distribution by wind were distributed instead by animals.
Background
Many taxa have been classified according to the longevity of their seeds in the soil seed bank. Seeds of transient species remain viable in the soil seed bank only to the next opportunity to germinate, while seeds of persistent species can survive longer than the next opportunity—often much longer than one year. Species with seeds that remain viable in the soil longer than five years form the long-term persistent seed bank, while species whose seeds generally germinate or die within one to five years are called short-term persistent. A typical long-term persistent species is Chenopodium album (Lambsquarters); its seeds commonly remain viable in the soil for up to 40 years and in rare situations perhaps as long as 1,600 years. A species forming no soil seed bank at all (except the dry season between ripening and the first autumnal rains) is Agrostemma githago (Corncockle), which was formerly a widespread cereal weed.
Seed longevity
Longevity of seeds is very var
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https://en.wikipedia.org/wiki/Reference%20model
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A reference model—in systems, enterprise, and software engineering—is an abstract framework or domain-specific ontology consisting of an interlinked set of clearly defined concepts produced by an expert or body of experts to encourage clear communication. A reference model can represent the component parts of any consistent idea, from business functions to system components, as long as it represents a complete set. This frame of reference can then be used to communicate ideas clearly among members of the same community.
Reference models are often illustrated as a set of concepts with some indication of the relationships between the concepts.
Overview
According to OASIS (Organization for the Advancement of Structured Information Standards) a reference model is "an abstract framework for understanding significant relationships among the entities of some environment, and for the development of consistent standards or specifications supporting that environment. A reference model is based on a small number of unifying concepts and may be used as a basis for education and explaining standards to a non-specialist. A reference model is not directly tied to any standards, technologies or other concrete implementation details, but it does seek to provide a common semantics that can be used unambiguously across and between different implementations."
There are a number of concepts rolled up into that of a 'reference model.' Each of these concepts is important:
Abstract: a reference model is abstract. It provides information about environments of a certain kind. A reference model describes the type or kind of entities that may occur in such an environment, not the particular entities that actually do occur in a specific environment. For example, when describing the architecture of a particular house (which is a specific environment of a certain kind), an actual exterior wall may have dimensions and materials, but the concept of a wall (type of entity) is part of the
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https://en.wikipedia.org/wiki/Classmates.com
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classmates.com is a social networking service. It was founded on November 17, 1995 by Randy Conrads as Classmates Online, Inc.
It originally sought to help users find class members and colleagues from kindergarten, primary school, high school, college, workplaces, and the U.S. military. In 2010, CEO Mark Goldston described the transition of the website "to increasingly focus on nostalgic content" such as "high school yearbooks, movie trailers, music tracks, and photographic images". To this end, and to appeal more to older users, the website name was changed to Memory Lane, which included a website redesign. This change was short-lived, however. Classmates dropped the Memory Lane brand in 2011.
Corporate information
United Online, Inc. (Nasdaq: UNTD) acquired Classmates Online in 2004 and owned and operated the company as part of its Classmates Media Corporation subsidiary until 2015.
Classmates Media operated online social networking and loyalty marketing services under the Classmates.com and MyPoints brands, respectively.
Classmates Media also operated the following international sites designed to enable users to connect with old friends:
StayFriends.de (Germany)
StayFriends.se (Sweden)
StayFriends.at (Austria)
Trombi.com (France)
In May 2016, the StayFriends sites were sold to Ströer.
In August 2015, Classmates was acquired from United Online by PeopleConnect Holdings, Inc., a portfolio company of H.I.G. Capital, for $30 million. Classmates is now operated as a division of PeopleConnect, which also owns Intelius.
Classmates Media Corporation's business model is based on user-generated content and revenue from paid subscriptions and advertising sales.
Users and ranking among other social networking sites
The only time Classmates appeared on Hitwise's top 10 list of social networking websites was June 2009, when it appeared tenth with 0.45% market share.
In early 2008, Nielsen Online had ranked Classmates as number three in unique monthly visitors (U.S.
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https://en.wikipedia.org/wiki/Password%20manager
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A password manager is a computer program that allows users to store and manage their passwords for local applications or online services such as web applications, online shops or social media.
Password managers can generate passwords and fill online forms. Password managers may exist as a mix of: computer applications, mobile applications, or as web browser extensions.
A password manager may assist in generating passwords, storing passwords, usually in an encrypted database. Aside from passwords, these applications may also store data such as credit card information, addresses, and frequent flyer information.
The main purpose of password managers is to alleviate a cyber-security phenomenon known as password fatigue, where an end-user can become overwhelmed from remembering multiple passwords for multiple services and which password is used for what service.
Password managers typically require a user to create and remember one "master" password to unlock and access all information stored in the application. Password managers may choose to integrate multi-factor authentication through fingerprints, or through facial recognition software. Although, this is not required to use the application/browser extension.
Password managers may be installed on a computer or mobile device as an application or as a browser extension.
History
The first password manager software designed to securely store passwords was Password Safe created by Bruce Schneier, which was released as a free utility on September 5, 1997. Designed for Microsoft Windows 95, Password Safe used Schneier's Blowfish algorithm to encrypt passwords and other sensitive data. Although Password Safe was released as a free utility, due to U.S. cryptography export restrictions in place at the time, only U.S. and Canadian citizens and permanent residents were initially allowed to download it.
Criticisms
Vulnerabilities
Some applications store passwords as an unencrypted file, leaving the passwords easily ac
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https://en.wikipedia.org/wiki/Broad%20ligament%20of%20the%20uterus
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The broad ligament of the uterus is the wide fold of peritoneum that connects the sides of the uterus to the walls and floor of the pelvis.
Structure
Subdivisions
Contents
The contents of the broad ligament include the following:
Reproductive
uterine tubes (or Fallopian tube)
ovary (some sources consider the ovary to be on the broad ligament, but not in it.)
vessels
ovarian artery (in the suspensory ligament)
uterine artery (in reality, travels in the cardinal ligament)
ligaments
ovarian ligament
round ligament of uterus
suspensory ligament of the ovary (Some sources consider it a part of the broad ligament, while other sources just consider it a "termination" of the ligament.)
Relations
The peritoneum surrounds the uterus like a flat sheet that folds over its fundus, covering it anteriorly and posteriorly; on the sides of the uterus, this sheet of peritoneum comes in direct contact with itself, forming the double layer of peritoneum known as the broad ligament of the uterus.
The part where this peritoneal sheet is folded (i.e. the free edge) has the uterine tubes running between the two layers; this part is known as the mesosalpinx.
Function
The broad ligament serves as a mesentery for the uterus, ovaries, and the uterine tubes. It helps in maintaining the uterus in its position, but it is not a major contributing factor.
Clinical significance
Broad ligament hernias are rare. Due to their vague clinical presentation they are difficult to distinguish from other types of internal hernias, which can cause small bowel obstruction.
Additional images
See also
Cardinal ligament
Pelvic diaphragm
Parametrium
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https://en.wikipedia.org/wiki/Intermediate%20mesoderm
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Intermediate mesoderm or intermediate mesenchyme is a narrow section of the mesoderm (one of the three primary germ layers) located between the paraxial mesoderm and the lateral plate of the developing embryo. The intermediate mesoderm develops into vital parts of the urogenital system (kidneys, gonads and respective tracts).
Early formation
Factors regulating the formation of the intermediate mesoderm are not fully understood. It is believed that bone morphogenic proteins, or BMPs, specify regions of growth along the dorsal-ventral axis of the mesoderm and plays a central role in formation of the intermediate mesoderm. Vg1/Nodal signalling is an identified regulator of intermediate mesoderm formation acting through BMP signalling. Excess Vg1/Nodal signalling during early gastrulation stages results in expansion of the intermediate mesoderm at the expense of the adjacent paraxial mesoderm, whereas inhibition of Vg1/Nodal signalling represses intermediate mesoderm formation. A link has been established between Vg1/Nodal signalling and BMP signalling, whereby Vg1/Nodal signalling regulates intermediate mesoderm formation by modulating the growth-inducing effects of BMP signalling.
Other necessary markers of intermediate mesoderm induction include the odd-skipped related gene (Osr1) and paired-box-2 gene (Pax2) which require intermediate levels of BMP signalling to activate Markers of early intermediate mesoderm formation are often not exclusive to the intermediate mesoderm. This can be seen in early stages of intermediate mesoderm differentiation where higher levels of BMP stimulate growth of lateral plate tissue, whilst lower concentrations lead to paraxial mesoderm and somite formation. Osr1, which encodes a zinc-finger DNA-binding protein, and LIM-type homeobox gene (Lhx1) expression overlaps the intermediate mesoderm as well as the lateral plate. Osr1 has expression domains encompassing the entire length of the anterior-posterior (AP) axis from the first somite
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https://en.wikipedia.org/wiki/Benzene%20in%20soft%20drinks
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Benzene in soft drinks is of potential concern due to the carcinogenic nature of the molecule. This contamination is a public health concern and has caused significant outcry among environmental and health advocates. Benzene levels are regulated in drinking water nationally and internationally, and in bottled water in the United States, but only informally in soft drinks. The benzene forms from decarboxylation of the preservative benzoic acid in the presence of ascorbic acid (vitamin C) and metal ions (iron and copper) that act as catalysts, especially under heat and light. Hot peppers naturally contain vitamin C ("nearly as much as in one orange") so the observation about soft drinks applies to pepper sauces containing sodium benzoate, like Texas Pete.
Formation in soft drinks
The major cause of benzene in soft drinks is the decarboxylation of benzoic acid in the presence of ascorbic acid (vitamin C, E300) or erythorbic acid (a diastereomer of ascorbic acid, E315). Benzoic acid is often added to drinks as a preservative in the form of its salts sodium benzoate (E211), potassium benzoate (E 212), or calcium benzoate (E 213). Citric acid is not thought to induce significant benzene production in combination with benzoic acid, but some evidence suggests that in the presence of ascorbic or erythorbic acid and benzoic acid, citric acid may accelerate the production of benzene.
The proposed mechanism begins with hydrogen abstraction by the hydroxyl radical, which itself is produced by the Cu2+-catalysed reduction of dioxygen by ascorbic acid:
Other factors that affect the formation of benzene are heat and light. Storing soft drinks in warm conditions speeds up the formation of benzene.
Calcium disodium EDTA and sugars have been shown to inhibit benzene production in soft drinks.
The International Council of Beverages Associations (ICBA) has produced advice to prevent or minimize benzene formation.
Limit standards in drinking water
Various authorities have set li
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https://en.wikipedia.org/wiki/Lonicera%20caerulea
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Lonicera caerulea, also known by its common names blue honeysuckle, sweetberry honeysuckle, fly honeysuckle (blue fly honeysuckle), blue-berried honeysuckle, or the honeyberry, is a non-climbing honeysuckle native throughout the cool temperate Northern Hemisphere regions of North America, Europe, and Asia.
The plant or its fruit has also come to be called haskap, derived from its name in the language of the native Ainu people of Hokkaido, Japan.
Description
Haskap is a deciduous shrub growing to tall. The leaves are opposite, oval, long and broad, greyish green, with a slightly waxy texture. The flowers are yellowish-white, 12–16 mm long, with five equal lobes; they are produced in pairs on the shoots. The fruit is an edible, blue berry, somewhat rectangular in shape weighing , and about in diameter.
The plant is winter-hardy and can tolerate temperatures below . Its flowers are frost-tolerant. Fruits mature early and are high in vitamin C.
Haskap cultivars can survive a large range of soil acidity from 3.9-7.7 (optimum 5.5-6.5), requiring high organic matter, well drained soils, and plentiful sunlight for optimum productivity. Lonicera caerulea plants are more tolerant of wet conditions than most fruit species.
Distribution and habitat
The species is circumpolar, primarily found in or near wetlands of boreal forests in heavy peat soils of North America, Europe, and Asia. It also can be found in high-calcium soils, in mountains, and along the coasts of northeastern Asia and northwestern North America.
Different varieties are distributed across central and northern Canada, northern United States, northern and eastern Europe, Siberia, middle Asia, and northeastern China.
Classification
The classification within the species is not settled. One classification uses nine botanical varieties:
Lonicera caerulea var. altaica. Northern Asia.
Lonicera caerulea var. caerulea. Europe.
Lonicera caerulea var. cauriana. Western North America.
Lonicera caerulea var. dep
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https://en.wikipedia.org/wiki/County%20flowers%20of%20the%20United%20Kingdom
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In 2002 Plantlife ran a "County Flowers" campaign to assign flowers to each of the counties of the United Kingdom and the Isle of Man. The results of this campaign designated a single plant species to a "county or metropolitan area" in the UK and Isle of Man. Some English counties already had flowers traditionally associated with them before 2002, and which were different from those assigned to them by Plantlife, including the white rose for Yorkshire (assigned the harebell), the poppy for Norfolk (assigned the Alexanders), and the cowslip for Essex (assigned the poppy). Some flowers were assigned to multiple counties.
England
Isle of Man
Northern Ireland
Scotland
Wales
Notes
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https://en.wikipedia.org/wiki/SSSE3
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Supplemental Streaming SIMD Extensions 3 (SSSE3 or SSE3S) is a SIMD instruction set created by Intel and is the fourth iteration of the SSE technology.
History
SSSE3 was first introduced with Intel processors based on the Core microarchitecture on June 26, 2006 with the "Woodcrest" Xeons.
SSSE3 has been referred to by the codenames Tejas New Instructions (TNI) or Merom New Instructions (MNI) for the first processor designs intended to support it.
Functionality
SSSE3 contains 16 new discrete instructions. Each instruction can act on 64-bit MMX or 128-bit XMM registers. Therefore, Intel's materials refer to 32 new instructions. They include:
Twelve instructions that perform horizontal addition or subtraction operations.
Six instructions that evaluate absolute values.
Two instructions that perform multiply-and-add operations and speed up the evaluation of dot products.
Two instructions that accelerate packed integer multiply operations and produce integer values with scaling.
Two instructions that perform a byte-wise, in-place shuffle according to the second shuffle control operand.
Six instructions that negate packed integers in the destination operand if the corresponding element in the source operand is negative.
Two instructions that align data from the composite of two operands.
CPUs with SSSE3
AMD:
"Cat" low-power processors
Bobcat-based processors
Jaguar-based processors and newer
Puma-based processors and newer
"Heavy Equipment" processors
Bulldozer-based processors
Piledriver-based processors
Steamroller-based processors
Excavator-based processors and newer
Zen-based processors
Zen+-based processors
Zen2-based processors
Zen3-based processors
Zen4-based processors
Intel:
Xeon 5100 Series
Xeon 5300 Series
Xeon 5400 Series
Xeon 3000 Series
Core 2 Duo
Core 2 Extreme
Core 2 Quad
Core i7
Core i5
Core i3
Pentium Dual Core (if 64-bit capable; Allendale onwards)
Celeron 4xx Sequence Conroe-L
Celeron Dual Core E1200
Celeron M 500 s
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https://en.wikipedia.org/wiki/Naturalistic%20decision-making
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The naturalistic decision making (NDM) framework emerged as a means of studying how people make decisions and perform cognitively complex functions in demanding, real-world situations. These include situations marked by limited time, uncertainty, high stakes, team and organizational constraints, unstable conditions, and varying amounts of experience.
The NDM framework and its origins
The NDM movement originated at a conference in Dayton, Ohio in 1989, which resulted in a book by Gary Klein, Judith Orasanu, Roberta Calderwood, and Caroline Zsambok. The NDM framework focuses on cognitive functions such as decision making, sensemaking, situational awareness, and planning – which emerge in natural settings and take forms that are not easily replicated in the laboratory. For example, it is difficult to replicate high stakes, or to achieve extremely high levels of expertise, or to realistically incorporate team and organizational constraints. Therefore, NDM researchers rely on cognitive field research methods such as task analysis to observe and study skilled performers. From the perspective of scientific methodology, NDM studies usually address the initial stages of observing phenomena and developing descriptive accounts. In contrast, controlled laboratory studies emphasize the testing of hypotheses. NDM and controlled experimentation are thus complementary approaches. NDM provides the observations and models, and controlled experimentation provides the testing and formalization.
Recognition-primed decision-making model (RPD)
The present form of RPD has three main variations. In the first variation, the decision maker when faced with the problem at hand, responds with the course of action that was first generated. In the second variation, the decision maker tries to understand the course of events that led up to the current situation, using mental simulation. In the final variation, the decision maker evaluates each course of action generated and then chooses th
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https://en.wikipedia.org/wiki/184%20%28number%29
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184 (one hundred [and] eighty-four) is the natural number following 183 and preceding 185.
In mathematics
There are 184 different Eulerian graphs on eight unlabeled vertices, and 184 paths by which a chess rook can travel from one corner of a 4 × 4 chessboard to the opposite corner without passing through the same square twice. 184 is also a refactorable number.
In other fields
Some physicists have proposed that 184 is a magic number for neutrons in atomic nuclei.
In poker, with one or more jokers as wild cards, there are 184 different straight flushes.
See also
The year AD 184 or 184 BC
List of highways numbered 184
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https://en.wikipedia.org/wiki/Comparison%20of%20issue-tracking%20systems
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Notable issue tracking systems, including bug tracking systems, help desk and service desk issue tracking systems, as well as asset management systems, include the following. The comparison includes client-server application, distributed and hosted systems.
General
Systems listed on a light purple background are no longer in active development.
Features
Input interfaces
Notification interfaces
Revision control system integration
Authentication methods
Containers
See also
Comparison of help desk issue tracking software
List of personal information managers
Comparison of project management software
Networked Help Desk
OSS through Java
Notes
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https://en.wikipedia.org/wiki/Beamrider
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Beamrider is a fixed shooter written for the Intellivision by David Rolfe and published by Activision in 1983. The game was ported to the Atari 2600 (with a slightly reduced feature set), Atari 5200, Atari 8-bit family, ColecoVision, Commodore 64, ZX Spectrum, and MSX.
Gameplay
Beamrider takes place above Earth's atmosphere, where a large alien shield called the Restrictor Shield surrounds the Earth. The player's objective is to clear the Shield's 99 sectors of alien craft while piloting the Beamrider ship. The Beamrider is equipped with a short-range laser lariat and a limited supply of torpedoes. The player is given three at the start of each sector.
To clear a sector, fifteen enemy ships must be destroyed. A "Sentinel ship" will then appear, which can be destroyed using a torpedo (if any remain) for bonus points. Some enemy ships can only be destroyed with torpedoes, and some must simply be dodged. Occasionally during a sector, "Yellow Rejuvenators" (extra lives) appear. They can be picked up for an extra ship, but if they are shot they will transform into ship-damaging debris.
Activision offered a Beamrider patch to players who could get to Sector 14 with 40,000 points and sent in a screenshot of their accomplishment.
Reception
The Deseret News in 1984 gave the ColecoVision version of Beamrider three stars, describing it as "basically a slide-and-shoot space game."
A reviewer for Your Commodore described the Commodore 64 version of the game as "a really good, wholesome arcade zapping game."
See also
List of Activision games: 1980–1999
Radar Scope (1979)
Juno First (1983)
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https://en.wikipedia.org/wiki/Fish
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A fish (: fish or fishes) is an aquatic, craniate, gill-bearing animal that lacks limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts.
The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods.
Most fish are ectothermic ("cold-blooded"), allowing their body temperatures to vary as ambient temperatures change, though some of the large active swimmers like white shark and tuna can hold a higher core temperature. Fish can acoustically communicate with each other, most often in the context of feeding, aggression or courtship.
Fish are abundant in most bodies of water. They can be found in nearly all aquatic environments, from high mountain streams (e.g., char and gudgeon) to the abyssal and even hadal depths of the deepest oceans (e.g., cusk-eels and snailfish), although no species has yet been documented in the deepest 25% of the ocean. With 34,300 described species, fish exhibit greater species diversity than any other group of vertebrates.
Fish are an important resource for humans worldwide, especially as food. Commercial and subsistence fishers hunt fish in wild fisheries or farm them in ponds or in cages in the ocean (in aquaculture). They are also caught by recreational
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https://en.wikipedia.org/wiki/History%20of%20entropy
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The concept of entropy developed in response to the observation that a certain amount of functional energy released from combustion reactions is always lost to dissipation or friction and is thus not transformed into useful work. Early heat-powered engines such as Thomas Savery's (1698), the Newcomen engine (1712) and the Cugnot steam tricycle (1769) were inefficient, converting less than two percent of the input energy into useful work output; a great deal of useful energy was dissipated or lost. Over the next two centuries, physicists investigated this puzzle of lost energy; the result was the concept of entropy.
In the early 1850s, Rudolf Clausius set forth the concept of the thermodynamic system and posited the argument that in any irreversible process a small amount of heat energy δQ is incrementally dissipated across the system boundary. Clausius continued to develop his ideas of lost energy, and coined the term entropy.
Since the mid-20th century the concept of entropy has found application in the field of information theory, describing an analogous loss of data in information transmission systems.
Classical thermodynamic views
In 1803, mathematician Lazare Carnot published a work entitled Fundamental Principles of Equilibrium and Movement. This work includes a discussion on the efficiency of fundamental machines, i.e. pulleys and inclined planes. Carnot saw through all the details of the mechanisms to develop a general discussion on the conservation of mechanical energy. Over the next three decades, Carnot's theorem was taken as a statement that in any machine the accelerations and shocks of the moving parts all represent losses of moment of activity, i.e. the useful work done. From this Carnot drew the inference that perpetual motion was impossible. This loss of moment of activity was the first-ever rudimentary statement of the second law of thermodynamics and the concept of 'transformation-energy' or entropy, i.e. energy lost to dissipation and frict
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https://en.wikipedia.org/wiki/Drumhead%20%28sign%29
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The term drumhead refers to a type of removable sign that was prevalent on North American railroads of the first half of the 20th century. The sign was mounted at the rear of named passenger trains, and consisted of a box with internal illumination that shone through a tinted panel bearing the logo of the railroad or specific train. Since the box and the sign were usually circular in shape and resembled small drums, they came to be known as drumheads.
Railroad drumheads were removable so that they could be mounted on different passenger cars (usually on the rear of observations), as needed for specific trains.
See also
Headboard
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https://en.wikipedia.org/wiki/Balsa%20wood%20bridge
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The building of balsa-wood bridges is often used as an educational technology. It may be accompanied by a larger project involving varying areas of study.
Typically classes which would include a balsa wood bridge cover the subject areas of physics, engineering, static equilibrium, or building trades, although it may be done independently of any of these subjects. Building a balsa wood bridge can be done after completing a section or unit covering a related topic or the process of design and building can be used to guide students to a better understanding of the desired subject area.
Requirements
Although there is great variety between different balsa wood bridge projects, students are in general trying to build a bridge that can withstand the greatest weight before it fails. Other restrictions are often applied, but these vary widely from one contest to another.
Sample requirements include:
restricting the maximum mass of the bridge
requiring a minimum span
requiring a minimum height of the roadway
restricting the physical dimensions of the bridge
restricting the size of individual pieces of balsa wood
limiting the amount of glue or balsa wood that can be used
requiring a driveable roadway that allows passage of a vehicle of specified size
restricting the way pieces are placed on the bridge (for example no parallel joining pieces)
Testing
Bridges are usually tested by applying a downward force on the bridge. How and where the force is applied varies from one contest to the next. There are two common methods of applying the test force to the bridge:
By hanging a container (such as a trash can) from the bridge and loading known weights into the container until the bridge breaks. The tester could also slowly add water or sand to the container until the bridge breaks and then weigh the container, providing a more accurate way to find the breaking force.
By using a mechanical or pneumatic testing device that pushes down on the bridge with increasing force until the
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https://en.wikipedia.org/wiki/Entropy%20%28classical%20thermodynamics%29
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In classical thermodynamics, entropy () is a property of a thermodynamic system that expresses the direction or outcome of spontaneous changes in the system. The term was introduced by Rudolf Clausius in the mid-19th century to explain the relationship of the internal energy that is available or unavailable for transformations in form of heat and work. Entropy predicts that certain processes are irreversible or impossible, despite not violating the conservation of energy. The definition of entropy is central to the establishment of the second law of thermodynamics, which states that the entropy of isolated systems cannot decrease with time, as they always tend to arrive at a state of thermodynamic equilibrium, where the entropy is highest. Entropy is therefore also considered to be a measure of disorder in the system.
Ludwig Boltzmann explained the entropy as a measure of the number of possible microscopic configurations of the individual atoms and molecules of the system (microstates) which correspond to the macroscopic state (macrostate) of the system. He showed that the thermodynamic entropy is , where the factor has since been known as the Boltzmann constant.
Concept
Differences in pressure, density, and temperature of a thermodynamic system tend to equalize over time. For example, in a room containing a glass of melting ice, the difference in temperature between the warm room and the cold glass of ice and water is equalized by energy flowing as heat from the room to the cooler ice and water mixture. Over time, the temperature of the glass and its contents and the temperature of the room achieve a balance. The entropy of the room has decreased. However, the entropy of the glass of ice and water has increased more than the entropy of the room has decreased. In an isolated system, such as the room and ice water taken together, the dispersal of energy from warmer to cooler regions always results in a net increase in entropy. Thus, when the system of the room
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https://en.wikipedia.org/wiki/Policy%20Governance
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Policy Governance, informally known as the Carver model, is a system for organizational governance. Policy Governance defines and guides appropriate relationships between an organization's owners, board of directors, and chief executive.
The Policy Governance approach was first developed in the 1970s by John Carver who has registered the term as a service mark in order to control accurate description of the model. The model is available for all to use without royalties or license fees and has been adopted by commercial, nonprofit, and public sector organizations.
Principles of Policy Governance
There are ten Principles of Policy Governance.
The trust in trusteeship.
The Board speaks with one voice or not at all.
Board decisions should predominantly be policy decisions.
Board should formulate policy by determining the broadest values before progressing to more narrow ones.
A board should define and delegate, rather than react and ratify.
Ends determination is the pivotal duty of governance.
The board's best control over staff means is to limit, not prescribe.
A board must explicitly design its own products and process.
A board must forge a linkage with management that is both empowering and safe.
Performance of the CEO must be monitored rigorously, but only against policy criteria.
Principles 1-3 define an organization's ownership, the board's responsibility to it, and the board's authority. Principles 4-7 specify that the board defines in writing policies identifying the benefits that should come about from the organization, how the board should conduct itself, and how staff behavior is to be proscribed. Principles 8-10 deal with the board's delegation and monitoring.
In general, if a board applies ALL of the principles of Policy Governance in its process and decision-making, then the board is likely practicing the model. If a board applies fewer than all the principles, it weakens or destroys the model’s effectiveness as a system.
Claims for the mod
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https://en.wikipedia.org/wiki/Entropy%20%28statistical%20thermodynamics%29
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The concept entropy was first developed by German physicist Rudolf Clausius in the mid-nineteenth century as a thermodynamic property that predicts that certain spontaneous processes are irreversible or impossible. In statistical mechanics, entropy is formulated as a statistical property using probability theory. The statistical entropy perspective was introduced in 1870 by Austrian physicist Ludwig Boltzmann, who established a new field of physics that provided the descriptive linkage between the macroscopic observation of nature and the microscopic view based on the rigorous treatment of large ensembles of microstates that constitute thermodynamic systems.
Boltzmann's principle
Ludwig Boltzmann defined entropy as a measure of the number of possible microscopic states (microstates) of a system in thermodynamic equilibrium, consistent with its macroscopic thermodynamic properties, which constitute the macrostate of the system. A useful illustration is the example of a sample of gas contained in a container. The easily measurable parameters volume, pressure, and temperature of the gas describe its macroscopic condition (state). At a microscopic level, the gas consists of a vast number of freely moving atoms or molecules, which randomly collide with one another and with the walls of the container. The collisions with the walls produce the macroscopic pressure of the gas, which illustrates the connection between microscopic and macroscopic phenomena.
A microstate of the system is a description of the positions and momenta of all its particles. The large number of particles of the gas provides an infinite number of possible microstates for the sample, but collectively they exhibit a well-defined average of configuration, which is exhibited as the macrostate of the system, to which each individual microstate contribution is negligibly small. The ensemble of microstates comprises a statistical distribution of probability for each microstate, and the group of most proba
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https://en.wikipedia.org/wiki/Entropy%20as%20an%20arrow%20of%20time
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Entropy is one of the few quantities in the physical sciences that require a particular direction for time, sometimes called an arrow of time. As one goes "forward" in time, the second law of thermodynamics says, the entropy of an isolated system can increase, but not decrease. Thus, entropy measurement is a way of distinguishing the past from the future. In thermodynamic systems that are not isolated, local entropy can decrease over time, accompanied by a compensating entropy increase in the surroundings; examples include objects undergoing cooling, living systems, and the formation of typical crystals.
Much like temperature, despite being an abstract concept, everyone has an intuitive sense of the effects of entropy. For example, it is often very easy to tell the difference between a video being played forwards or backwards. A video may depict a wood fire that melts a nearby ice block, played in reverse it would show that a puddle of water turned a cloud of smoke into unburnt wood and froze itself in the process. Surprisingly, in either case the vast majority of the laws of physics are not broken by these processes, a notable exception being the second law of thermodynamics. When a law of physics applies equally when time is reversed, it is said to show T-symmetry; in this case, entropy is what allows one to decide if the video described above is playing forwards or in reverse as intuitively we identify that only when played forwards the entropy of the scene is increasing. Because of the second law of thermodynamics, entropy prevents macroscopic processes showing T-symmetry.
When studying at a microscopic scale, the above judgements cannot be made. Watching a single smoke particle buffeted by air, it would not be clear if a video was playing forwards or in reverse, and, in fact, it would not be possible as the laws which apply show T-symmetry. As it drifts left or right, qualitatively it looks no different; it is only when the gas is studied at a macroscopic sca
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https://en.wikipedia.org/wiki/Prothallus
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A prothallus, or prothallium, (from Latin pro = forwards and Greek θαλλος (thallos) = twig) is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young gametophyte of a liverwort or peat moss as well. In lichens it refers to the region of the thallus that is free of algae.
The prothallus develops from a germinating spore. It is a short-lived and inconspicuous heart-shaped structure typically 2–5 millimeters wide, with a number of rhizoids (root-like hairs) growing underneath, and the sex organs: archegonium (female) and antheridium (male). Appearance varies quite a lot between species. Some are green and conduct photosynthesis while others are colorless and nourish themselves underground as saprotrophs.
Alternation of generations
Spore-bearing plants, like all plants, go through a life-cycle of alternation of generations. The fully grown sporophyte, what is commonly referred to as the fern, produces genetically unique spores in the sori by meiosis. The haploid spores fall from the sporophyte and germinate by mitosis, given the right conditions, into the gametophyte stage, the prothallus. The prothallus develops independently for several weeks; it grows sex organs that produce ova (archegonia) and flagellated sperm (antheridia). The sperm are able to swim to the ova for fertilization to form a diploid zygote which divides by mitosis to form a multicellular sporophyte. In the early stages of growth, the sporophyte grows out of the prothallus, depending on it for water supply and nutrition, but develops into a new independent fern, which will produce new spores that will grow into new prothallia etc., thus completing the life cycle of the organism.
Theoretical advantages of alternation of generations
It has been argued that there is an important evolutionary advantages to the alternation of generations plant life-cycle. By forming a multicellular haploid gametophyte rather than limiting the
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https://en.wikipedia.org/wiki/Ramsey%E2%80%93Cass%E2%80%93Koopmans%20model
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The Ramsey–Cass–Koopmans model, or Ramsey growth model, is a neoclassical model of economic growth based primarily on the work of Frank P. Ramsey, with significant extensions by David Cass and Tjalling Koopmans. The Ramsey–Cass–Koopmans model differs from the Solow–Swan model in that the choice of consumption is explicitly microfounded at a point in time and so endogenizes the savings rate. As a result, unlike in the Solow–Swan model, the saving rate may not be constant along the transition to the long run steady state. Another implication of the model is that the outcome is Pareto optimal or Pareto efficient.
Originally Ramsey set out the model as a social planner's problem of maximizing levels of consumption over successive generations. Only later was a model adopted by Cass and Koopmans as a description of a decentralized dynamic economy with a representative agent. The Ramsey–Cass–Koopmans model aims only at explaining long-run economic growth rather than business cycle fluctuations, and does not include any sources of disturbances like market imperfections, heterogeneity among households, or exogenous shocks. Subsequent researchers therefore extended the model, allowing for government-purchases shocks, variations in employment, and other sources of disturbances, which is known as real business cycle theory.
Mathematical description
Model setup
In the usual setup, time is continuous starting, for simplicity, at and continuing forever. By assumption, the only productive factors are capital and labour , both required to be nonnegative. The labour force, which makes up the entire population, is assumed to grow at a constant rate , i.e. , implying that with initial level at . Finally, let denote aggregate production, and denote aggregate consumption.
The variables that the Ramsey–Cass–Koopmans model ultimately aims to describe are , the per capita (or more accurately, per labour) consumption, as well as , the so-called capital intensity. It does so by fi
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https://en.wikipedia.org/wiki/Raster%20scan
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A raster scan, or raster scanning, is the rectangular pattern of image capture and reconstruction in television. By analogy, the term is used for raster graphics, the pattern of image storage and transmission used in most computer bitmap image systems. The word raster comes from the Latin word rastrum (a rake), which is derived from radere (to scrape); see also rastrum, an instrument for drawing musical staff lines. The pattern left by the lines of a rake, when drawn straight, resembles the parallel lines of a raster: this line-by-line scanning is what creates a raster. It is a systematic process of covering the area progressively, one line at a time. Although often a great deal faster, it is similar in the most general sense to how one's gaze travels when one reads lines of text.
In most modern graphics cards the data to be drawn is stored internally in an area of semiconductor memory called the framebuffer. This memory area holds the values for each pixel on the screen. These values are retrieved from the refresh buffer and painted onto the screen one row at a time.
Description
Scan lines
In a raster scan, an image is subdivided into a sequence of (usually horizontal) strips known as "scan lines". Each scan line can be transmitted in the form of an analog signal as it is read from the video source, as in television systems, or can be further divided into discrete pixels for processing in a computer system. This ordering of pixels by rows is known as raster order, or raster scan order. Analog television has discrete scan lines (discrete vertical resolution), but does not have discrete pixels (horizontal resolution) – it instead varies the signal continuously over the scan line. Thus, while the number of scan lines (vertical resolution) is unambiguously defined, the horizontal resolution is more approximate, according to how quickly the signal can change over the course of the scan line.
Scanning pattern
In raster scanning, the beam sweeps horizontally left-
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https://en.wikipedia.org/wiki/Ecological%20island
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An ecological island is a term used in New Zealand, and increasingly in Australia, to refer to an area of land (not necessarily an actual island) isolated by natural or artificial means from the surrounding land, where a natural micro-habitat exists amidst a larger differing ecosystem. In New Zealand the term is used to refer to one of several types of nationally protected areas.
In artificial ecological islands (also known as mainland islands):
all non-native species (at least predator species) have been eradicated,
native species are reintroduced and nurtured, and
the natural or artificial border is maintained to prevent reintroduction of non-native species.
The ultimate goal is to recreate an ecological microcosm of the country as a whole as it was before human arrival. There is usually provision for controlled public access, and scientific study and research.
The definition does not include land within a fence erected to:
protect farm animals from wild predators
protect a specific species from specific predators
exclude farm animals only
exclude native animals (although some native animals, weka for example, may need to be excluded during a species' recovery phase).
Background
The concept of mainland islands was pioneered in New Zealand and arose mainly from the particular circumstances of that country's history. For millions of years New Zealand was part of the supercontinent Gondwanaland, which included Australia, Africa, and South America, and shared the same flora and fauna. About 70 million years ago New Zealand became separated, earlier than Australia, South America and Antarctica. About five million years later non-avian dinosaurs became globally extinct leaving the way open to mammals to dominate - except in New Zealand where there were no land mammals (only 3 species of bats and seals). In the absence of mammals, birds became dominant. Evolutionary processes resulted in a unique assemblage of plants and animals, and New Zealand became
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https://en.wikipedia.org/wiki/Whitehead%27s%20lemma
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Whitehead's lemma is a technical result in abstract algebra used in algebraic K-theory. It states that a matrix of the form
is equivalent to the identity matrix by elementary transformations (that is, transvections):
Here, indicates a matrix whose diagonal block is and entry is .
The name "Whitehead's lemma" also refers to the closely related result that the derived group of the stable general linear group is the group generated by elementary matrices. In symbols,
.
This holds for the stable group (the direct limit of matrices of finite size) over any ring, but not in general for the unstable groups, even over a field. For instance for
one has:
where Alt(3) and Sym(3) denote the alternating resp. symmetric group on 3 letters.
See also
Special linear group#Relations to other subgroups of GL(n,A)
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https://en.wikipedia.org/wiki/Nernst%E2%80%93Planck%20equation
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The Nernst–Planck equation is a conservation of mass equation used to describe the motion of a charged chemical species in a fluid medium. It extends Fick's law of diffusion for the case where the diffusing particles are also moved with respect to the fluid by electrostatic forces. It is named after Walther Nernst and Max Planck.
Equation
The Nernst–Planck equation is a continuity equation for the time-dependent concentration of a chemical species:
where is the flux. It is assumed that the total flux is composed of three elements: diffusion, advection, and electromigration. This implies that the concentration is affected by an ionic concentration gradient , flow velocity , and an electric field :
where is the diffusivity of the chemical species, is the valence of ionic species, is the elementary charge, is the Boltzmann constant, and is the absolute temperature. The electric field may be further decomposed as:
where is the electric potential and is the magnetic vector potential. Therefore, the Nernst–Planck equation is given by:
Simplifications
Assuming that the concentration is at equilibrium and the flow velocity is zero, meaning that only the ion species moves, the Nernst–Planck equation takes the form:
Rather than a general electric field, if we assume that only the electrostatic component is significant, the equation is further simplified by removing the time derivative of the magnetic vector potential:
Finally, in units of mol/(m2·s) and the gas constant , one obtains the more familiar form:
where is the Faraday constant equal to ; the product of Avogadro constant and the elementary charge.
Applications
The Nernst–Planck equation is applied in describing the ion-exchange kinetics in soils. It has also been applied to membrane electrochemistry.
See also
Goldman–Hodgkin–Katz equation
Bioelectrochemistry
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https://en.wikipedia.org/wiki/Information%20dimension
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In information theory, information dimension is an information measure for random vectors in Euclidean space, based on the normalized entropy of finely quantized versions of the random vectors. This concept was first introduced by Alfréd Rényi in 1959.
Simply speaking, it is a measure of the fractal dimension of a probability distribution. It characterizes the growth rate of the Shannon entropy given by successively finer discretizations of the space.
In 2010, Wu and Verdú gave an operational characterization of Rényi information dimension as the fundamental limit of almost lossless data compression for analog sources under various regularity constraints of the encoder/decoder.
Definition and Properties
The entropy of a discrete random variable is
where is the probability measure of when , and the denotes a set .
Let be an arbitrary real-valued random variable. Given a positive integer , we create a new discrete random variable
where the is the floor operator which converts a real number to the greatest integer less than it. Then
and
are called lower and upper information dimensions of respectively. When , we call this value information dimension of ,
Some important properties of information dimension :
If the mild condition is fulfilled, we have .
For an -dimensional random vector , the first property can be generalized to .
It is sufficient to calculate the upper and lower information dimensions when restricting to the exponential subsequence .
and are kept unchanged if rounding or ceiling functions are used in quantization.
d-Dimensional Entropy
If the information dimension exists, one can define the -dimensional entropy of this distribution by
provided the limit exists. If , the zero-dimensional entropy equals the standard Shannon entropy . For integer dimension , the -dimensional entropy is the -fold integral defining the respective differential entropy.
An equivalent definition of Information Dimension
In 1994, Kawabata and Dem
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https://en.wikipedia.org/wiki/Mac%20gaming
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Mac gaming refers to the use of video games on Macintosh personal computers. In the 1990s, Apple computers did not attract the same level of video game development as Microsoft Windows computers due to the high popularity of Microsoft Windows and, for 3D gaming, Microsoft's DirectX technology. In recent years, the introduction of Mac OS X and support for Intel processors has eased porting of many games, including 3D games through use of OpenGL and more recently Apple's own Metal API. Virtualization technology and Boot Camp also permit the use of Windows and its games on Macintosh computers. Today, a growing number of popular games run natively on macOS, though as of early 2019, a majority still require the use of Microsoft Windows.
macOS Catalina (and later) eliminated support for 32-bit games, including those compatible with older versions of macOS.
Early game development on the Mac
Prior to the release of the Macintosh 128K, the first Macintosh computer, marketing executives at Apple feared that including a game in the finished operating system would aggravate the impression that the graphical user interface made the Mac toy-like. More critically, the limited amount of RAM in the original Macintosh meant that fitting a game into the operating system would be very difficult. Eventually, Andy Hertzfeld created a Desk Accessory called Puzzle that occupied only 600 bytes of memory. This was deemed small enough to be safely included in the operating system, and it shipped with the Mac when released in 1984. With Puzzle—the first computer game specifically for a mouse—the Macintosh became the first computer with a game in its ROM, and it would remain a part of the Mac OS for the next ten years, until being replaced in 1994 with Jigsaw, a jigsaw puzzle game included as part of System 7.5.
During the development of the Mac, a chess game similar to Archon based on Alice in Wonderland was shown to the development team. The game was written by Steve Capps for the Apple L
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https://en.wikipedia.org/wiki/Cyclic%20code
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In coding theory, a cyclic code is a block code, where the circular shifts of each codeword gives another word that belongs to the code. They are error-correcting codes that have algebraic properties that are convenient for efficient error detection and correction.
Definition
Let be a linear code over a finite field (also called Galois field) of block length . is called a cyclic code if, for every codeword from , the word in obtained by a cyclic right shift of components is again a codeword. Because one cyclic right shift is equal to cyclic left shifts, a cyclic code may also be defined via cyclic left shifts. Therefore, the linear code is cyclic precisely when it is invariant under all cyclic shifts.
Cyclic codes have some additional structural constraint on the codes. They are based on Galois fields and because of their structural properties they are very useful for error controls. Their structure is strongly related to Galois fields because of which the encoding and decoding algorithms for cyclic codes are computationally efficient.
Algebraic structure
Cyclic codes can be linked to ideals in certain rings. Let be a polynomial ring over the finite field . Identify the elements of the cyclic code with polynomials in such that
maps to the polynomial
: thus multiplication by corresponds to a cyclic shift. Then is an ideal in , and hence principal, since is a principal ideal ring. The ideal is generated by the unique monic element in of minimum degree, the generator polynomial .
This must be a divisor of . It follows that every cyclic code is a polynomial code.
If the generator polynomial has degree then the rank of the code is .
The idempotent of is a codeword such that (that is, is an idempotent element of ) and is an identity for the code, that is for every codeword . If and are coprime such a word always exists and is unique; it is a generator of the code.
An irreducible code is a cyclic code in which the code, as an ideal i
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https://en.wikipedia.org/wiki/Even%20code
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A binary code is called an even code if the Hamming weight of each of its codewords is even. An even code should have a generator polynomial that include (1+x) minimal polynomial as a product. Furthermore, a binary code is called doubly even if the Hamming weight of all its codewords is divisible by 4. An even code which is not doubly even is said to be strictly even.
Examples of doubly even codes are the extended binary Hamming code of block length 8 and the extended binary Golay code of block length 24. These two codes are, in addition, self-dual.
Coding theory
Parity (mathematics)
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https://en.wikipedia.org/wiki/Computer%20Memories%2C%20Inc.
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Computer Memories, Inc. (CMI) was a Chatsworth, California manufacturer of hard disk drives during the early 1980s. CMI made basic stepper motor-based drives, with low cost in mind.
History
The company was founded in 1979 by Raymond Brooke, Abraham Brand, James Willets and James Quackenbush all formerly of Pertec Computer Corporation, with initial seed money from Raymond Brooke and Abraham Brand and investors Irwin Rubin, Frederic Heim and Marshall Butler. It was incorporated August 6, 1979. Initially the company offered three 5 1/4" disk drives with a capacity of 5, 10 or 15 megabytes (unformatted). Early investors in the company included Intel Corporation. The company made an initial public offering on August 23, 1983 of approximately 2,000,000 shares of common stock. August 1984 they secured a major contract as sole producer of 20-megabyte hard drives for the base model of the IBM PC/AT. Unfortunately, the Singapore-manufactured CM6000 drives proved highly unreliable. Dealers reported failure rates as high as 25 to 30 percent. Part of the problem was high demand for the PC/AT; IBM increased its order from 90,000 units in 1984 to 240,000 in 1985, and manufacturing quality suffered. Second, the design of the disk drive subsystem itself was flawed.
At the same time, Quantum Corporation sued CMI for patent infringement relating to the servo mechanism in the entire CM6600 line of drives. Instead of putting the tracking grating on the head arm and driving the arm directly from a voice coil, like the Quantum designs, CMI made a composite motor that would bolt to the drive in place of the usual stepper motor, with the voice coil on the bottom and the tracking mechanism on top (similar to DC servo motors used in process controls and robotics). CMI connected the motor to the arm with a metal-band pulley, the same mechanism they used on their stepper-motor drives. Since the feedback system was behind the pulley, it had to compensate for slack in the arm, one of several t
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https://en.wikipedia.org/wiki/TIM-001
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TIM-001 was an application development microcomputer developed by Mihajlo Pupin Institute (Serbia) in 1983/84.
See also
Mihajlo Pupin Institute
Literature
Dragoljub Milićević, Dušan Hristović (Ed): Računari TIM, Naučna knjiga, Belgrade 1990. In Serbian.
Dušan Hristović: Razvoj računarstva u Srbiji (Computing in Serbia), Phlogiston journal, No 18/19, pp. 89-105, Museum MNT-SANU, Belgrade 2010/2011. In Serbian.
D.B.Vujaklija, N.Markovic (Ed): 50 Years of computing in Serbia, pp.37-44, DIS, IMP and PC-Press, Belgrade 2011.
Mihajlo Pupin Institute
Computing by computer model
IBM PC compatibles
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https://en.wikipedia.org/wiki/Coprostanol
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5β-Coprostanol (5β-cholestan-3β-ol) is a 27-carbon stanol formed from the biohydrogenation of cholesterol (cholest-5en-3β-ol) in the gut of most higher animals and birds. This compound has frequently been used as a biomarker for the presence of human faecal matter in the environment.
Chemical properties
Solubility
5β-coprostanol has a low water solubility, and consequently a high octanol-water partition coefficient (log Kow = 8.82). This means that in most environmental systems, 5β-coprostanol will be associated with the solid phase.
Degradation
In anaerobic sediments and soils, 5β-coprostanol is stable for many hundreds of years enabling it to be used as an indicator of past faecal discharges. As such, records of 5β-coprostanol from paleo-environmental archives have been used to further constrain the timing of human settlements in a region, as well as reconstruct relative changes in human populations and agricultural activities over several thousand years.
Chemical analysis
Since the molecule has a hydroxyl (-OH) group, it is frequently bound to other lipids including fatty acids; most analytical methods, therefore, utilise a strong alkali (KOH or NaOH) to saponify the ester linkages. Typical extraction solvents include 6% KOH in methanol. The free sterols and stanols (saturated sterols) are then separated from the polar lipids by partitioning into a less polar solvent such as hexane. Prior to analysis, the hydroxyl group is frequently derivatised with BSTFA (bis-trimethyl silyl trifluoroacetamide) to replace the hydrogen with the less exchangeable trimethylsilyl (TMS) group. Instrumental analysis is frequently conducted on gas chromatograph (GC) with either a flame ionisation detector (FID) or mass spectrometer (MS). The mass spectrum for 5β-coprostanol - TMS ether can be seen in the figure.
Isomers
As well as the faecally derived stanol, two other isomers can be identified in the environment; 5α-cholestanol
Formation and occurrence
Faecal sources
5β-copro
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https://en.wikipedia.org/wiki/Iskra%20Delta%20Partner
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Iskra Delta Partner was a computer developed by Iskra Delta in 1983.
Specifications
Text mode: 26 lines with 80 or 132 characters each
Character set: YUSCII
I/O ports: three RS-232C, one used to connect printer (1200-4800 bit/s) and two general-purpose (300-9600 bit/s)
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https://en.wikipedia.org/wiki/Gorenje%20Dialog
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Dialog was a microcomputer system developed by Gorenje in 1980s. It was based on the 8-bit 4 MHz Zilog Z-80A microprocessor. The primary operating system was FEDOS (CP/M 2.2 compatible), developed by Computer Structures and Systems Laboratory (Faculty of Electrical Engineering, University of Ljubljana) and Gorenje.
There were 3 variants of the Dialog microcomputer system, distinguished only by minor changed: home, laboratory and personal (PC) (in Slovene: hišni, laboratorijski, osebni). Three types of external memory can be connected with Dialog: cassette recorder, floppy drive (5,25" and 8") and hard drive. The home variant of Dialog used resident FEBASIC (a variant of BASIC).
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https://en.wikipedia.org/wiki/Iskradata%201680
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Iskradata 1680 was a computer developed by Iskradata in 1979.
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https://en.wikipedia.org/wiki/Ocean%20stratification
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Ocean stratification is the natural separation of an ocean's water into horizontal layers by density, which is generally stable because warm water floats on top of cold water, and heating is mostly from the sun, which reinforces that arrangement. Stratification is reduced by wind-forced mechanical mixing, but reinforced by convection (warm water rising, cold water sinking). Stratification occurs in all ocean basins and also in other water bodies. Stratified layers are a barrier to the mixing of water, which impacts the exchange of heat, carbon, oxygen and other nutrients. The surface mixed layer is the uppermost layer in the ocean and is well mixed by mechanical (wind) and thermal (convection) effects. Climate change is causing the upper ocean stratification to increase.
Due to upwelling and downwelling, which are both wind-driven, mixing of different layers can occur through the rise of cold nutrient-rich and sinking of warm water, respectively. Generally, layers are based on water density: heavier, and hence denser, water is below the lighter water, representing a stable stratification. For example, the pycnocline is the layer in the ocean where the change in density is largest compared to that of other layers in the ocean. The thickness of the thermocline is not constant everywhere and depends on a variety of variables.
Between 1960 and 2018, upper ocean stratification increased between 0.7-1.2% per decade due to climate change. This means that the differences in density of the layers in the oceans increase, leading to larger mixing barriers and other effects. In the last few decades, stratification in all ocean basins has increased due to effects of climate change on oceans. Global upper-ocean stratification has continued its increasing trend in 2022. The southern oceans (south of 30°S) experienced the strongest rate of stratification since 1960, followed by the Pacific, Atlantic, and the Indian Oceans. Increasing stratification is predominantly affected by
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https://en.wikipedia.org/wiki/CER-202
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CER ( – Digital Electronic Computer) model 202 is an early digital computer developed by Mihajlo Pupin Institute (Serbia) in the 1960s.
See also
CER Computers
Mihajlo Pupin Institute
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https://en.wikipedia.org/wiki/Stack%20effect
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The stack effect or chimney effect is the movement of air into and out of buildings through unsealed openings, chimneys, flue-gas stacks, or other containers, resulting from air buoyancy. Buoyancy occurs due to a difference in indoor-to-outdoor air density resulting from temperature and moisture differences. The result is either a positive or negative buoyancy force. The greater the thermal difference and the height of the structure, the greater the buoyancy force, and thus the stack effect. The stack effect helps drive natural ventilation, air infiltration, and fires (e.g. the Kaprun tunnel fire, King's Cross underground station fire and the Grenfell Tower fire).
Stack effect in buildings
Since buildings are not totally sealed (at the very minimum, there is always a ground level entrance), the stack effect will cause air infiltration. During the heating season, the warmer indoor air rises up through the building and escapes at the top either through open windows, ventilation openings, or unintentional holes in ceilings, like ceiling fans and recessed lights. The rising warm air reduces the pressure in the base of the building, drawing cold air in through either open doors, windows, or other openings and leakage. During the cooling season, the stack effect is reversed, but is typically weaker due to lower temperature differences.
In a modern high-rise building with a well-sealed envelope, the stack effect can create significant pressure differences that must be given design consideration and may need to be addressed with mechanical ventilation. Stairwells, shafts, elevators, and the like, tend to contribute to the stack effect, while interior partitions, floors, and fire separations can mitigate it. Especially in case of fire, the stack effect needs to be controlled to prevent the spread of smoke and fire, and to maintain tenable conditions for occupants and firefighters. While natural ventilation methods may be effective, such as air outlets being installed c
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https://en.wikipedia.org/wiki/Thomas%20Banchoff
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Thomas Francis Banchoff (born April 7, 1938) is an American mathematician
specializing in geometry. He is a professor at Brown University, where he has taught since 1967. He is known for his research in differential geometry in three and four dimensions, for his efforts to develop methods of computer graphics in the early 1990s, and most recently for his pioneering work in methods of undergraduate education utilizing online resources.
Banchoff graduated from the University of Notre Dame in 1960, receiving his B.A. in Mathematics, and received his Masters and Ph.D. from UC Berkeley in 1962 and 1964, where he was a student of Shiing-Shen Chern. Before going to Brown he taught at Harvard University and the University of Amsterdam. In 2012 he became a fellow of the American Mathematical Society. In addition, he was a president of the Mathematical Association of America.
Selected works
with Stephen Lovett: Differential Geometry of Curves and Surfaces (2nd edition), A. K. Peters 2010
with Terence Gaffney, Clint McCrory: Cusps of Gauss Mappings, Pitman 1982
with John Wermer: Linear Algebra through Geometry, Springer Verlag 1983
Beyond the third dimension: geometry, computer graphics, and higher dimensions, Scientific American Library, Freeman 1990
Triple points and surgery of immersed surfaces. Proc. Amer. Math. Soc. 46 (1974), 407–413. (concerning the number of triple points of immersed surfaces in .)
Critical points and curvature for embedded polyhedra. Journal of Differential Geometry 1 (1967), 245–256. (Theorem of Gauß-Bonnet for Polyhedra)
Teaching Experience
Benjamin Peirce Instructor, Harvard, 1964 - 1966
Research Associate, Universiteit van Amsterdam, 1966 - 1967;
Brown University:
Asst Professor, 1967
Associate Professor 1970
Professor 1973 - 2014
G. Leonard Baker Visiting Professor of Mathematics, Yale, 1998
Visiting Professor, University of Notre Dame, 2001
Visiting Professor, UCLA, 2002
Visiting Professor, University of Georgia, 2006
Vi
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https://en.wikipedia.org/wiki/RpoB
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The rpoB gene encodes the β subunit of bacterial RNA polymerase and the homologous plastid-encoded RNA polymerase (PEP). It codes for 1342 amino acids in E. coli, making it the second-largest polypeptide in the bacterial cell. It is targeted by the rifamycin family of antibacterials, such as rifampin. Mutations in rpoB that confer resistance to rifamycins do so by altering the protein's drug-binding residues, thereby reducing affinity for these antibiotics.
Some bacteria contain multiple copies of the 16S rRNA gene, which is commonly used as the molecular marker to study phylogeny. In these cases, the single-copy rpoB gene can be used to study microbial diversity.
An inhibitor of transcription in bacteria, tagetitoxin, also inhibits PEP, showing that the complex found in plants is very similar to the homologous enzyme in bacteria.
Drug resistance
In a bacterium without the proper mutation(s) in rpoB rifampicin binds to a site near the fork in the β subunit and prevents the polymerase from transcribing more than two or three base pairs of any RNA sequence and stopping production of proteins within the cell. Bacteria with mutations in the proper loci along the rpoB gene are resistant to this effect.
Initial studies were done by Jin and Gross to generate rpoB mutations in E. coli that conferred resistance to rifampicin. Three clusters of mutations were identified, cluster I at codons 507-533, cluster II at codons 563-572, and cluster III at codon 687. The majority of these mutations are located within an 81 base pair(bp) region in cluster I dubbed the "Rifampicin Resistance Determining Region (RRDR)". This resistance is typically associated with a mutation wherein a base in the DNA is substituted for another one and the new sequence codes for an amino acid with a large side chain that inhibits the rifampicin molecules from binding to the polymerase.
There are additional mutations which can occur in the β subunit of the polymerase which are located away from the
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https://en.wikipedia.org/wiki/Inventory%20turnover
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In accounting, the inventory turnover is a measure of the number of times inventory is sold or used in a time period such as a year. It is calculated to see if a business has an excessive inventory in comparison to its sales level. The equation for inventory turnover equals the cost of goods sold divided by the average inventory. Inventory turnover is also known as inventory turns, merchandise turnover, stockturn, stock turns, turns, and stock turnover.
Formulas
The formula for inventory turnover:
or
or
The most basic formula for average inventory:
or just
Multiple data points, for example, the average of the monthly averages, will provide a much more representative turn figure.
The average days to sell the inventory is calculated as follows:
Application in Business
A low turnover rate may point to overstocking, obsolescence, or deficiencies in the product line or marketing effort. However, in some instances a low rate may be appropriate, such as where higher inventory levels occur in anticipation of rapidly rising prices or expected market shortages. Another insight provided by the inventory turnover ratio is that if inventory is turning over slowly, then the warehousing cost attributable to each unit will be higher.
Conversely a high turnover rate may indicate inadequate inventory levels, which may lead to a loss in business as the inventory is too low. This often can result in stock shortages.
Some compilers of industry data (e.g., Dun & Bradstreet) use sales as the numerator instead of cost of sales. Cost of sales yields a more realistic turnover ratio, but it is often necessary to use sales for purposes of comparative analysis. Cost of sales is considered to be more realistic because of the difference in which sales and the cost of sales are recorded. Sales are generally recorded at market value, i.e. the value at which the marketplace paid for the good or service provided by the firm. In the event that the firm had an exceptional year an
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https://en.wikipedia.org/wiki/Midsphere
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In geometry, the midsphere or intersphere of a convex polyhedron is a sphere which is tangent to every edge of the polyhedron. Not every polyhedron has a midsphere, but the uniform polyhedra, including the regular, quasiregular and semiregular polyhedra and their duals all have midspheres. The radius of the midsphere is called the midradius. A polyhedron that has a midsphere is said to be midscribed about this sphere.
When a polyhedron has a midsphere, one can form two perpendicular circle packings on the midsphere, one corresponding to the adjacencies between vertices of the polyhedron, and the other corresponding in the same way to its polar polyhedron, which has the same midsphere. The length of each polyhedron edge is the sum of the distances from its two endpoints to their corresponding circles in this circle packing.
For every convex polyhedron there is a combinatorially equivalent polyhedron, the canonical polyhedron, that does have a midsphere, centered at the centroid of the points of tangency of the edges. Numerical approximation algorithms can construct it, but its coordinates cannot be represented exactly as a closed-form expression. Any canonical polyhedron and its polar dual can be used to form two opposite faces of a four-dimensional antiprism.
Definition and examples
A midsphere of a three-dimensional convex polyhedron is defined to be a sphere that is tangent to every edge of the polyhedron. That is to say, each edge must touch it, at an interior point of the edge, without crossing it. Equivalently, it is a sphere that contains the inscribed circle of every face of the polyhedron. When a midsphere exists, it is unique. Not every convex polyhedron has a midsphere; to have a midsphere, every face must have an inscribed circle (that is, it must be a tangential polygon), and all of these inscribed circles must belong to a single sphere. For example, a rectangular cuboid has a midsphere only when it is a cube, because otherwise it has non-square recta
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https://en.wikipedia.org/wiki/Biosafety%20Clearing-House
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The Biosafety Clearing-House is an international mechanism that exchanges information about the movement of genetically modified organisms, established under the Cartagena Protocol on Biosafety. It assists Parties (i.e. governments that have ratified the Protocol) to implement the protocol’s provisions and to facilitate sharing of information on, and experience with, living modified organisms (also known as genetically modified organisms, GMOs). It further assists Parties and other stakeholders to make informed decisions regarding the importation or release of GMOs.
The Biosafety Clearing-House Central Portal is accessible through the Web. The BCH is a distributed system, and information in it is owned and updated by the users themselves through an authenticated system to ensure timeliness and accuracy.
Mandate
Article 20, paragraph 1 of the Cartagena Protocol on Biosafety established the BCH as part of the clearing-house mechanism of the Convention on Biological Diversity, in order to:
(a) Facilitate the exchange of scientific, technical, environmental and legal information on, and experience with, living modified organisms; and
(b) Assist Parties to implement the Protocol, taking into account the special needs of developing country Parties, in particular the least developed and small island developing States among them, and countries with economies in transition as well as countries that are centres of origin and centres of genetic diversity.
First use in international law
The BCH differs from other similar mechanisms established under other international legal agreements because it is in fact essential for the successful implementation of its parent body, the Protocol. It was the first Internet-based information-exchange mechanism created that must be used to fulfil certain international legal obligations - not only do Parties to the Protocol have a legal obligation to provide certain types of information to the BCH within defined time-frames, but certa
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https://en.wikipedia.org/wiki/Gametangium
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A gametangium (: gametangia) is an organ or cell in which gametes are produced that is found in many multicellular protists, algae, fungi, and the gametophytes of plants. In contrast to gametogenesis in animals, a gametangium is a haploid structure and formation of gametes does not involve meiosis.
Types of gametangia
Depending on the type of gamete produced in a gametangium, several types can be distinguished.
Female
Female gametangia are most commonly called archegonia. They produce egg cells and are the sites for fertilization. Archegonia are common in algae and primitive plants as well as gymnosperms. In flowering plants, they are replaced by the embryo sac inside the ovule.
Male
The male gametangia are most commonly called antheridia. They produce sperm cells that they release for fertilization. Antheridia producing non-motile sperm (spermatia) are called spermatangia. Some antheridia do not release their sperm. For example, the oomycete antheridium is a syncytium with many sperm nuclei and fertilization occurs via fertilization tubes growing from the antheridium and making contact with the egg cells. Antheridia are common in the gametophytes in "lower" plants such as bryophytes, ferns, cycads and ginkgo. In "higher" plants such as conifers and flowering plants, they are replaced by pollen grains.
Isogamous
In isogamy, the gametes look alike and cannot be classified into "male" or "female." For example, in zygomycetes, two gametangia (single multinucleate cells at the end of hyphae) form good contact with each other and fuse into a zygosporangium. Inside the zygosporangium, the nuclei from each of the original two gametangia pair up.
See also
Zoosporangium, a gametangium that produces motile isogamous gametes, called zoospores
Reproduction
Reproductive system
Germ cells
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https://en.wikipedia.org/wiki/YUSCII
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YUSCII is an informal name for several JUS standards for 7-bit character encoding. These include:
JUS I.B1.002 (ISO-IR-141, ISO 646-YU), which encodes Gaj's Latin alphabet, used for Serbo-Croatian and Slovenian language
JUS I.B1.003 (ISO-IR-146), which encodes Serbian Cyrillic alphabet, and
JUS I.B1.004 (ISO-IR-147), which encodes Macedonian Cyrillic alphabet.
The encodings are based on ISO 646, 7-bit Latinic character encoding standard, and were used in Yugoslavia before widespread use of later CP 852, ISO-8859-2/8859-5, Windows-1250/1251 and Unicode standards. It was named after ASCII, having the first word "American" replaced with "Yugoslav": "Yugoslav Standard Code for Information Interchange". Specific standards are also sometimes called by a local name: SLOSCII, CROSCII or SRPSCII for JUS I.B1.002, SRPSCII for JUS I.B1.003, MAKSCII for JUS I.B1.004.
JUS I.B1.002 is a national ISO 646 variant, i.e. equal to basic ASCII with less frequently used symbols replaced with specific letters of Gaj's alphabet. Cyrillic standards further replace Latin alphabet letters with corresponding Cyrillic letters. Љ (lj), Њ (nj), Џ (dž) and ѕ (dz) correspond to Latin digraphs, and are mapped over Latin letters which are not used in Serbian or Macedonian (q, w, x, y).
YUSCII was originally developed for teleprinters but it also spread for computer use. This was widely considered a bad idea among software developers who needed the original ASCII such as {, [, }, ], ^, ~, |, \ in their source code (an issue partly addressed by trigraphs in C). On the other hand, an advantage of YUSCII is that it remains comparatively readable even when support for it is not available, similarly to the Russian KOI-7. Numerous attempts to replace it with something better kept failing due to limited support. Eventually, Microsoft's introduction of code pages, appearance of Unicode and availability of fonts finally spelled sure (but nevertheless still slow) end of YUSCII.
Codepage layout
Code poin
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https://en.wikipedia.org/wiki/Vancouver%20Community%20Network
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Vancouver Community Network (VCN) is a community-owned provider of free internet access, technical support, and web hosting services to individuals and nonprofit organizations in Vancouver, British Columbia.
It developed StreetMessenger, a communication service for the homeless.
History
The organization was founded as Vancouver FreeNet by Brian Campbell and others.
Revenue Canada initially rejected VCN's application status as a charitable organization, which would have allowed it to receive tax-deductible contributions. VCN appealed this decision, and in 1997, the Federal Court of Appeal ruled that providing free internet service was a charitable tax purpose.
See also
Chebucto Community Network
Free-Net
Wireless community network
Community informatics
National Capital Freenet
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https://en.wikipedia.org/wiki/Angioblast
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Angioblasts (or vasoformative cells) are embryonic cells from which the endothelium of blood vessels arises. They are derived from embryonic mesoderm. Blood vessels first make their appearance in several scattered vascular areas (blood islands) that are developed simultaneously between the endoderm and the mesoderm of the yolk-sac, i. e., outside the body of the embryo. Here a new type of cell, the angioblast, is differentiated from the mesoderm.
These cells as they divide form small, dense syncytial masses, which soon join with similar masses by means of fine processes to form plexuses. They form capillaries through vasculogenesis and angiogenesis.
Angioblasts are one of the two products formed from hemangioblasts (the other being multipotential hemopoietic stem cells).
See also
List of human cell types derived from the germ layers
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https://en.wikipedia.org/wiki/Backyard%20Wildlife%20Habitat
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The Backyard Wildlife Habitat is a program of the National Wildlife Federation that encourages homeowners in the United States to manage their gardens and yards as a wildlife garden, with the goal of maintaining healthy and diverse animal habitats and ecosystems. The program began in 1973. By 1998, it had impacted more than 21,000 yards and, as of 2006, has certified over 60,000 'backyards'.
Certification
To be a certified Backyard Wildlife Habitat, a garden or yard, or any outdoor space from a balcony up to a multi-acre tract of land, must offer food, water, shelter, and a place for raising young to beneficial insects or animals. Over time the Federation has introduced variants or expansions of the program for schoolyards and for communities.
In order for a backyard to be certified as a Backyard Wildlife Habitat by the National Wildlife Federation, the space must do all of the following: provide food, water, cover, a place to raise young, and be maintained in a way that has a positive effect on the health of the soil, air, water, and habitat for native wildlife. More specifically, the presence of native forbs, shrubs, and trees is necessary to provide food. Water can be supplied by natural features such as a streams, ponds, or wetlands, or by human-made features such as bird baths. Native vegetation can also provide cover and places for wildlife to raise their young, as can brush piles or dead trees. With all of these features in place, it is crucial that the land be cared for thoughtfully and as naturally as possible. Avoid the use of chemical pesticides and fertilizers, reduce the area that turf grass occupies, utilize mulch obtained from sustainable forestry practices, and minimize water use in order to maintain the integrity of the soil, air, and water in and outside of the habitat.
Effectiveness and success
Prior to 2004 there was no scientific study as to whether backyard habitats actually help butterflies. A study published in 2004 of the effect
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https://en.wikipedia.org/wiki/Hemocyte%20%28invertebrate%20immune%20system%20cell%29
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A hemocyte is a cell that plays a role in the immune system of invertebrates. It is found within the hemolymph.
Hemocytes are phagocytes of invertebrates.
Hemocytes in Drosophila melanogaster can be divided into two categories: embryonic and larval. Embryonic hemocytes are derived from head mesoderm and enter the hemolymph as circulating cells. Larval hemocytes, on the other hand, are responsible for tissue remodeling during development. Specifically, they are released during the pupa stage in order to prepare the fly for the transition into an adult and the massive associated tissue reorganization that must occur.
There are four basic types of hemocytes found in fruit flies: secretory, plasmatocytes, crystal cells, and lamellocytes. Secretory cells are never released into the hemolymph and instead send out signalling molecules responsible for cell differentiation. Plasmatocytes are the hemocytes responsible for cell ingestion (phagocytosis) and represent about 95% of circulating hemocytes. Crystal cells are only found in the larval stage of Drosophila, and they are involved in melanization, a process by which microbes/pathogens are engulfed in a hardened gel and destroyed via anti-microbial peptides and other proteins involved in the humoral response. They constitute about 5% of circulating hemocytes. Lamellocytes are flat cells that are never found in adult cells, and instead are only present in larval cells for their ability to encapsulate invading pathogens. They specifically act on parasitic wasp eggs that bind to the surfaces of cells, and are incapable of being phagocytosed by host cells.
In mosquitoes, hemocytes are functionally divided into three populations: granulocytes, oenocytoids and prohemocytes. Granulocytes are the most abundant cell type. They rapidly attach to foreign surfaces and readily engage in phagocytosis. Oenocytoids do not readily spread on foreign surfaces and are the major producers of phenoloxidase, which is the major enzyme
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https://en.wikipedia.org/wiki/White%20ramus%20communicans
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The white ramus communicans (: rami communicantes) from Latin ramus (branch) and communicans (communicating) is the preganglionic sympathetic outflow nerve tract from the spinal cord.
Each of the thoracic, and the first and second lumbar nerves contribute a white ramus communicans to the adjoining sympathetic ganglion, unlike the gray rami which are located at each spinal level. White rami communicantes contain both myelinated and unmyelinated preganglionic sympathetic fibers, (GVE and GVA). The white ramus appears white because there are more myelinated than unmyelinated fibers unlike the gray rami.
Structure
The white rami communicantes are the preganglionic sympathetic outflow from the spinal cord.
The cell bodies for the preganglionic sympathetic myelinated fibers in the white rami communicantes lie in the ipsilateral (same sided) intermediolateral cell column in the spinal cord which extends from T1-L2. These rami also contain general visceral afferent fibers (sensory from the organs) whose primary cell bodies reside dorsal root ganglia (which then synapse in the dorsal horn). The preganglionic sympathetic fibers will enter into the sympathetic trunk and either synapse at the ganglion on the same level, or travel up or down the sympathetic trunk to arrive at the correct spinal level for their action. Once they synapse in the sympathetic ganglion in the sympathetic trunk, they exit the trunk as gray rami to join the spinal nerve and innervate the appropriate structure. Even though the sympathetic trunk extends below L2, there are no more white rami communicantes below L2 because the intermediolateral cell column ends before this. The fibers of the sympathetic trunk above and below T1-L2 originate from white rami communicantes within T1-L2. Above and below T1-L2 there are only gray rami. Cell column are the important features of white rami communicates.
Additional Images
See also
Gray ramus communicans
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https://en.wikipedia.org/wiki/Gray%20ramus%20communicans
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Each spinal nerve receives a branch called a gray ramus communicans (: rami communicantes) from the adjacent paravertebral ganglion of the sympathetic trunk. The gray rami communicantes contain postganglionic nerve fibers of the sympathetic nervous system and are composed of largely unmyelinated neurons. This is in contrast to the white rami communicantes, in which heavily myelinated neurons give the rami their white appearance.
Function
Preganglionic sympathetic fibers from the intermediolateral nucleus in the lateral grey column of the spinal cord are carried in the white ramus communicans to the paravertebral ganglia of the sympathetic trunk. Once the preganglionic nerve has traversed a white ramus communicans, it can do one of three things.
The preganglionic neuron can synapse with a postganglionic sympathetic neuron in the sympathetic paravertebral ganglion at that level. From here, the postganglionic sympathetic neuron can travel back out the grey ramus communicans of that level to the mixed spinal nerve and onto the effector organ.
The preganglionic neuron can travel superiorly or inferiorly to a sympathetic paravertebral ganglion of a higher or lower level where it can synapse with a postganglionic sympathetic neuron. From here, the postganglionic sympathetic neuron can travel back out the grey ramus communicans of that level to the mixed spinal nerve and on to an effector organ.
The preganglionic neuron can pass through the paravertebral ganglion without synapsing, and therefore continue as a preganglionic nerve fiber (Splanchnic nerves) until it reaches a distant collateral ganglion anterior to the vertebral column (Prevertebral ganglia). Once inside the prevertebral ganglia, the individual neurons comprising the nerve synapse with their postganglionic neuron. The postganglionic nerve then proceeds to innervate its targets (pelvic visceral organs) It will generally be responsible for the innervation of the pelvic viscera.
Ganglionic influence can be
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https://en.wikipedia.org/wiki/Pulmonary%20branches%20of%20vagus%20nerve
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The pulmonary branches of the vagus nerve can be divided into two groups: anterior and posterior.
Anterior
The Anterior Bronchial Branches (rami bronchiales anteriores; anterior or ventral pulmonary branches), two or three in number, and of small size, are distributed on the anterior surface of the root of the lung.
They join with filaments from the sympathetic, and form the anterior pulmonary plexus.
Posterior
The Posterior Bronchial Branches (rami bronchiales posteriores; posterior or dorsal pulmonary branches), more numerous and larger than the anterior, are distributed on the posterior surface of the root of the lung; they are joined by filaments from the third and fourth (sometimes also from the first and second) thoracic ganglia of the sympathetic trunk, and form the posterior pulmonary plexus.
Branches from this plexus accompany the ramifications of the bronchi through the substance of the lung.
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https://en.wikipedia.org/wiki/Pulmonary%20plexus
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The pulmonary plexus is an autonomic plexus formed from pulmonary branches of vagus nerve and the sympathetic trunk. The plexus is in continuity with the deep cardiac plexus.
Structure
It innervates the bronchial tree and the visceral pleura. According to the relation of nerves to the root of the lung, the pulmonary plexus is divided into the anterior pulmonary plexus, which lies in front of the lung and the posterior pulmonary plexus, which lies behind the lung. The anterior pulmonary plexus is close in proximity to the pulmonary artery. The posterior pulmonary plexus is bounded by the superior edge of the pulmonary artery and the lower edge of the pulmonary vein. Both lungs are innervated primarily by the posterior pulmonary plexus; it accounts for 74–77% of the total innervation.
Function
Innervation of the bronchial tree regulates contraction of bronchial smooth muscles, mucous secretions from submucosal glands, vascular permeability, and blood flow. Sensory fiber innervation of the visceral pleura is thought to allow stretch detection.
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https://en.wikipedia.org/wiki/Al%20the%20Octopus
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Al the Octopus is the mascot of the Detroit Red Wings of the National Hockey League. During many games, octopuses are thrown onto the ice by fans for good luck, this usually occurring after the national anthem is sung or after a goal is scored.
This Legend of the Octopus tradition, started on April 15, 1952, when two brothers, Pete and Jerry Cusimano, who owned a fish market, decided to throw an octopus onto the ice at Olympia Stadium, with the eight tentacles of the octopus symbolizing the eight wins it took to win the Stanley Cup at the time. The Red Wings were a perfect 7–0 in the playoffs and were one win away from not only winning the Cup, but becoming the first perfect team in the NHL's post season history. Sure enough the Red Wings won that game, and the media made mention of the octopus "omen" in the papers the following day, thus establishing the octopus legend in the process. Fans have been throwing octopuses onto the ice at Red Wings games ever since. The tradition died down somewhat in the 1970s and 1980s during the Red Wings dismal seasons, but when the Red Wings became contenders again in the 1990s, the tradition resumed.
Eventually, a drawn purple octopus mascot was created, and in the 1995 playoffs a large Octopus prop was unveiled. The Octopus was eventually named "Al" (after former Joe Louis Arena and Little Caesars Arena building operations manager Al Sobotka), and every playoff year since, Al the Octopus gets raised to the rafters, when the Red Wings skate out onto the ice. As the years went on some modifications were made to Al, such as making it so his pupils light up red (blinking on and off), the adding of a large Red Wing Jersey to his body, and the removal of a tooth in order to give Al that "hockey player" look. Al often appears on Red Wings apparel and promotional items. Coca-Cola would later create stuffed Als, in their Fan in the Can or Al in the Can promotion. The promotion featured cases of Coke in which some cans were, in fact, c
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https://en.wikipedia.org/wiki/Debug%20menu
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A debug menu or debug mode is a user interface implemented in a computer program that allows the user to view and/or manipulate the program's internal state for the purpose of debugging. Some games format their debug menu as an in-game location, referred to as a debug room (distinct from the developer's room type of Easter egg). Debug menus and rooms are used during software development for ease of testing and are usually made inaccessible or otherwise hidden from the end user.
Compared to the normal user interfaces, debug menus usually are unpolished and not user-friendly, intended only to be used by the software's developers. They are often cryptic and may allow for destructive actions such as erasing data without warning.
In video games
Debug menus are often of interest to video game players as they can be used to cheat, access unused content, or change the game configuration beyond what is normally allowed. Some game developers will reveal methods to access these menus as bonus features, while others may lock them out of the final version entirely such that they can only be accessed by modifying the program.
The Cutting Room Floor (TCRF) is a website dedicated to researching and documenting hidden content in video games, including debugging material. In December 2013, Edge described the website as "the biggest and most organised" of its kind, and by that time it had 3712 articles.
In other software
Debugging functions can be found in many other programs and consumer electronics as well. For example, many TVs and DVD players contain hidden menus that can be used to change settings that aren't accessible through the normal menus. Many cell phones also contain debug menus, usually used to test out functions of the phone to make sure they are working. For example, the hidden menu of the Samsung Galaxy S III has test functions for the vibrator, proximity sensor, sound, and other basic aspects of the phone.
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https://en.wikipedia.org/wiki/Superior%20hypogastric%20plexus
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The superior hypogastric plexus (in older texts, hypogastric plexus or presacral nerve) is a plexus of nerves situated on the vertebral bodies anterior to the bifurcation of the abdominal aorta. It bifurcates to form the left and the right hypogastric nerve. The SHP is the continuation of the abdominal aortic plexus.
Structure
Afferents
The superior hypogastric plexus receives contributions from the two lower lumbar splanchnic nerves (L3-L4), which are branches of the chain ganglia. They also contain parasympathetic fibers which arise from pelvic splanchnic nerve (S2-S4) and ascend from inferior hypogastric plexus; it is more usual for these parasympathetic fibers to ascend to the left-handed side of the superior hypogastric plexus and cross the branches of the sigmoid and left colic vessel branches, as these parasympathetic branches are distributed along the branches of the inferior mesenteric artery.
Efferents
From the plexus, sympathetic fibers are carried into the pelvis as two main trunks - the right and left hypogastric nerves - each lying medial to the internal iliac artery and its branches. The right and left hypogastric nerves continues as inferior hypogastric plexus; these hypogastric nerves send sympathetic fibers to the ovarian and ureteric plexuses, which originate within the renal and abdominal aortic sympathetic plexuses.
Relations
The superior hypogastric plexus is often displaced somewhat to the left of the midline. It is situated between the common iliac arteries. It is anterior to the lumbar vertebra L5 and sacral promontory, the aortic bifurcation, and left common iliac vein. It is posterior to the parietal peritoneum (with avascular areolar tissue intervening between these two structures). It is situated near the apex of the attachment of the sigmoid mesocolon.
Clinical significance
Presacral neurectomy is a laparoscopic procedure where superior hypogastric plexus is excised, so that the pain pathway is cut off from the spinal column. Th
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https://en.wikipedia.org/wiki/Celiac%20ganglia
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The celiac ganglia or coeliac ganglia are two large irregularly shaped masses of nerve tissue in the upper abdomen. Part of the sympathetic subdivision of the autonomic nervous system (ANS), the two celiac ganglia are the largest ganglia in the ANS, and they innervate most of the digestive tract.
They have the appearance of lymph glands and are placed on either side of the midline in front of the crura of the diaphragm, close to the suprarenal glands (also called adrenal glands). The ganglion on the right side is placed behind the inferior vena cava.
They are sometimes referred to as the semilunar ganglia or the solar ganglia.
Neurotransmission
The celiac ganglion is part of the sympathetic prevertebral chain possessing a great variety of specific receptors and neurotransmitters such as catecholamines, neuropeptides, and nitric oxide and constitutes a modulation center in the pathway of the afferent and efferent fibers between the central nervous system and the ovary.
The main preganglion neurotransmitter of the celiac ganglion is acetylcholine, yet the celiac ganglion-mesenteric complex also contain α and β adrenergic receptors and is innervated by fibers of adrenergic nature that come from other preaortic ganglia.
Path
The upper part of each ganglion is joined by the greater splanchnic nerve, while the lower part, which is segmented off and named the aorticorenal ganglion, receives the lesser splanchnic nerve and gives off the greater part of the renal plexus.
Innervation
These ganglia contain neurons whose postganglionic axons innervate the stomach, liver, gallbladder, spleen, kidney, small intestine, and the ascending and transverse colon. They directly innervate the ovarian theca and secondary interstitial cells and exert an indirect action on the luteal cells.
Links to ovary
Modifications in the adrenergic activity of the celiac ganglion results in an altered capacity of the ovary of pregnant rats to produce progesterone, suggesting that the celiac ga
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https://en.wikipedia.org/wiki/Isothermal%20titration%20calorimetry
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In chemical thermodynamics, isothermal titration calorimetry (ITC) is a physical technique used to determine the thermodynamic parameters of interactions in solution. It is most often used to study the binding of small molecules (such as medicinal compounds) to larger macromolecules (proteins, DNA etc.) in a label-free environment. It consists of two cells which are enclosed in an adiabatic jacket. The compounds to be studied are placed in the sample cell, while the other cell, the reference cell, is used as a control and contains the buffer in which the sample is dissolved.
The technique was developed by H. D. Johnston in 1968 as a part of his Ph.D. dissertation at Brigham Young University, and was considered niche until introduced commercially by MicroCal Inc. in 1988. Compared to other calorimeters, ITC has an advantage in not requiring any correctors since there was no heat exchange between the system and the environment.
Thermodynamic measurements
ITC is a quantitative technique that can determine the binding affinity (), enthalpy changes (), and binding stoichiometry () of the interaction between two or more molecules in solution. This is achieved from integrating the area of the injection peaks and plotting the individual values by molar ratio of the binding event versus \Delta H (kcal/mol). From these initial measurements, Gibbs free energy changes () and entropy changes () can be determined using the relationship:
(where is the gas constant and is the absolute temperature).
For accurate measurements of binding affinity, the curve of the thermogram must be sigmoidal. The profile of the curve is determined by the c-value, which is calculated using the equation:
where is the stoichiometry of the binding, is the association constant and is the concentration of the molecule in the cell. The c-value must fall between 1 and 1000, ideally between 10 and 100. In terms of binding affinity, it would be approximately from ~ within the limit range.
In
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https://en.wikipedia.org/wiki/Competition%20%28biology%29
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Competition is an interaction between organisms or species in which both require a resource that is in limited supply (such as food, water, or territory). Competition lowers the fitness of both organisms involved since the presence of one of the organisms always reduces the amount of the resource available to the other.
In the study of community ecology, competition within and between members of a species is an important biological interaction. Competition is one of many interacting biotic and abiotic factors that affect community structure, species diversity, and population dynamics (shifts in a population over time).
There are three major mechanisms of competition: interference, exploitation, and apparent competition (in order from most direct to least direct). Interference and exploitation competition can be classed as "real" forms of competition, while apparent competition is not, as organisms do not share a resource, but instead share a predator. Competition among members of the same species is known as intraspecific competition, while competition between individuals of different species is known as interspecific competition.
According to the competitive exclusion principle, species less suited to compete for resources must either adapt or die out, although competitive exclusion is rarely found in natural ecosystems. According to evolutionary theory, competition within and between species for resources is important in natural selection. More recently, however, researchers have suggested that evolutionary biodiversity for vertebrates has been driven not by competition between organisms, but by these animals adapting to colonize empty livable space; this is termed the 'Room to Roam' hypothesis.
Interference competition
During interference competition, also called contest competition, organisms interact directly by fighting for scarce resources. For example, large aphids defend feeding sites on cottonwood leaves by ejecting smaller aphids from better sites.
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https://en.wikipedia.org/wiki/Model%20transformation
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A model transformation, in model-driven engineering, is an automated way of modifying and creating platform-specific model from platform-independent ones. An example use of model transformation is ensuring that a family of models is consistent, in a precise sense which the software engineer can define. The aim of using a model transformation is to save effort and reduce errors by automating the building and modification of models where possible.
Overview
Model transformations can be thought of as programs that take models as input. There is a wide variety of kinds of model transformation and uses of them, which differ in their inputs and outputs and also in the way they are expressed.
A model transformation usually specifies which models are acceptable as input, and if appropriate what models it may produce as output, by specifying the metamodel to which a model must conform.
Classification of model transformations
Model transformations and languages for them have been classified in many ways.
Some of the more common distinctions drawn are:
Number and type of inputs and outputs
In principle a model transformation may have many inputs and outputs of various types; the only absolute limitation is that a model transformation will take at least one model as input. However, a model transformation that did not produce any model as output would more commonly be called a model analysis or model query.
Endogenous versus exogenous
Endogenous transformations are transformations between models expressed in the same language. Exogenous transformations are transformations between models expressed using different languages. For example, in a process conforming to the OMG Model Driven Architecture, a platform-independent model might be transformed into a platform-specific model by an exogenous model transformation.
Unidirectional versus bidirectional
A unidirectional model transformation has only one mode of execution: that is, it always takes the same type of input
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https://en.wikipedia.org/wiki/ShotCode
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ShotCode is a circular barcode created by High Energy Magic of Cambridge University. It uses a dartboard-like circle, with a bullseye in the centre and datacircles surrounding it. The technology reads databits from these datacircles by measuring the angle and distance from the bullseye for each.
ShotCodes are designed to be read with a regular camera (including those found on mobile phones and webcams) without the need to purchase other specialised hardware. ShotCodes differ from matrix barcodes in that they do not store regular data - rather, they store a look up number consisting of 40 bits of data. This needs to link to a server that holds information regarding a mapped URL which the reading device can connect to in order to download said data.
History
ShotCode was created in 1999 at the University of Cambridge when researching a low cost vision based method to track locations and developed TRIPCode as a result. It has been used to track printed TRIPCode paperbadges in realtime with webcams. After that in Cambridge it had another research use; to read barcodes with mobile phone cams, and they used TRIPCode in a round barcode which was named SpotCode. High Energy Magic was founded in 2003 to commercialise research from the University of Cambridge Computer Laboratory and Laboratory for Communications Engineering. Least Bango.net, a mobile company used SpotCode 2004 in their ads. In 2005 High Energy Magic Ltd. sold the entire SpotCode IPR to OP3. Afterwards the name was changed from SpotCode to ShotCode. Heineken was the first company to officially use the ShotCode technology.
ShotCode's software
The software used to read a ShotCode captured by a mobile camera is called ‘ShotReader’. It is lightweight and is only around 17kB. It ‘reads’ the camera’s picture of a ShotCode in real time and prompts the browsers to navigate to a particular site.
The last website update was from 2007, suggesting that updates for phones based on Android and iPhone will not be availa
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https://en.wikipedia.org/wiki/Requirement%20prioritization
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Requirement prioritization is used in the Software product management for determining which candidate requirements of a software product should be included in a certain release. Requirements are also prioritized to minimize risk during development so that the most important or high risk requirements are implemented first. Several methods for assessing a prioritization of software requirements exist.
Introduction
In Software product management there exist several sub processes. First of all there is portfolio management where a product development strategy is defined based on information from the market and partner companies. In product roadmapping (or technology roadmapping), themes and core assets of products in the portfolio are identified and roadmap constructions are created. In requirements management candidate software requirements for a product are gathered and organized. Finally, in the release planning activity, these requirements are prioritized and selected for a release, after which the launch of the software product can be prepared. Thus, one of the key steps in release planning is requirements prioritization.
Cost-value approach
A good and relatively easy to use method for prioritizing software product requirements is the cost-value approach. This approach was created by Joachim Karlsson and Kevin Ryan. The approach was then further developed and commercialized in the company Focal Point (that was acquired by Telelogic in 2005). Their basic idea was to determine for each individual candidate requirement what the cost of implementing the requirement would be and how much value the requirement has.
The assessment of values and costs for the requirements was performed using the Analytic Hierarchy Process (AHP). This method was created by Thomas Saaty. Its basic idea is that for all pairs of (candidate) requirements a person assesses a value or a cost comparing the one requirement of a pair with the other. For example, a value of 3 for (Req1, Req2) ind
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https://en.wikipedia.org/wiki/Digital%20Item
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Digital Item is the basic unit of transaction in the MPEG-21 framework. It is a structured digital object, including a standard representation, identification and metadata.
A Digital Item may be a combination of resources like videos, audio tracks or images; metadata, such as descriptors and identifiers; and structure for describing the relationships between the resources.
It is becoming difficult for users of content to identify and interpret the different intellectual property rights that are associated with the elements of multimedia content. For this reason, new solutions are required for the access, delivery, management and protection of this content.
Digital Item Declaration
MPEG-21 proposes to facilitate a wide range of actions involving Digital Items so there is a need for a very precise description for defining exactly what constitutes such an item.
A Digital Item Declaration (DID) is a document that specifies the makeup, structure and organisation of a Digital Item. The purpose of the Digital Item Declaration is to describe a set of abstract terms and concepts, to form a useful model for defining what a Digital Item is. Following this model, a Digital Item is the digital representation of an object, which is managed, described or exchanged within the model.
Digital Item Identification
Digital Item Identification (DII) specification includes not only how to identify Digital Items uniquely but also to distinguish different types of them. These Identifiers are placed in a specific part of the Digital Item Declaration, which is the statement element, and they are associated with Digital Items.
Digital Items and their parts are identified by encapsulating uniform resource identifiers, which are a compact string of characters for identifying an abstract or physical resource.
The elements of a DID can have zero, one or more descriptors; each descriptor may contain a statement which can contain an identifier relating to the parent element of the stateme
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https://en.wikipedia.org/wiki/History%20of%20the%20Dylan%20programming%20language
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Dylan programming language history first introduces the history with a continuous text. The second section gives a timeline overview of the history and present several milestones and watersheds. The third section presents quotations related to the history of the Dylan programming language.
Introduction to the history
Dylan was originally developed by Apple Cambridge, then a part of the Apple Advanced Technology Group (ATG). Its initial goal was to produce a new system programming application development programming language for the Apple Newton PDA, but soon it became clear that this would take too much time. Walter Smith developed NewtonScript for scripting and application development, and systems programming was done in the language C. Development continued on Dylan for the Macintosh. The group produced an early Technology Release of its Apple Dylan product, but the group was dismantled due to internal restructuring before they could finish any real usable products.
According to Apple Confidential by Owen W. Linzmayer, the original code name for the Dylan project was Ralph, for Ralph Ellison, author of the novel Invisible Man, to reflect its status as a secret research project.
The initial killer application for Dylan was the Apple Newton PDA, but the initial implementation came too late for it. Also, the performance and size objectives were missed. So Dylan was retargeted toward a general computer programming audience. To compete in this market, it was decided to switch to infix notation.
Andrew Shalit (along with David A. Moon and Orca Starbuck) wrote the Dylan Reference Manual, which served as a basis for work at Harlequin (software company) and Carnegie Mellon University. When Apple Cambridge was closed, several members went to Harlequin, which produces a working compiler and development environment for Microsoft Windows. When Harlequin got bought and split, some of the developers founded Functional Objects. In 2003, the firm contributed its repository to
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https://en.wikipedia.org/wiki/David%20Emmanuel%20%28mathematician%29
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David Emmanuel (31 January 1854 – 4 February 1941) was a Romanian Jewish mathematician and member of the Romanian Academy, considered to be the founder of the modern mathematics school in Romania.
Born in Bucharest, Emmanuel studied at Gheorghe Lazăr and Gheorghe Șincai high schools. In 1873 he went to Paris, where he received his Ph.D. in mathematics from the University of Paris (Sorbonne) in 1879 with a thesis on Study of abelian integrals of the third species, becoming the second Romanian to have a Ph.D. in mathematics from the Sorbonne (the first one was Spiru Haret). The thesis defense committee consisted of Victor Puiseux (advisor), Charles Briot, and Jean-Claude Bouquet.
In 1882, Emmanuel became a professor of superior algebra and function theory at the Faculty of Sciences of the University of Bucharest. Here, in 1888, he held the first courses on group theory and on Galois theory, and introduced set theory in Romanian education. Among his students were Anton Davidoglu, Alexandru Froda, Traian Lalescu, Grigore Moisil, , Miron Nicolescu, Octav Onicescu, Dimitrie Pompeiu, Simion Stoilow, and Gheorghe Țițeica. Emmanuel had an important role in the introduction of modern mathematics and of the rigorous approach to mathematics in Romania.
Emmanuel was the president of the first Congress of Romanian Mathematicians, held in 1929 in Cluj. He died in Bucharest in 1941.
A street in the Dorobanți neighborhood of Bucharest is named after him.
Publications
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https://en.wikipedia.org/wiki/Java%20%28software%20platform%29
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Java is a set of computer software and specifications that provides a software platform for developing application software and deploying it in a cross-platform computing environment. Java is used in a wide variety of computing platforms from embedded devices and mobile phones to enterprise servers and supercomputers. Java applets, which are less common than standalone Java applications, were commonly run in secure, sandboxed environments to provide many features of native applications through being embedded in HTML pages.
Writing in the Java programming language is the primary way to produce code that will be deployed as byte code in a Java virtual machine (JVM); byte code compilers are also available for other languages, including Ada, JavaScript, Python, and Ruby. In addition, several languages have been designed to run natively on the JVM, including Clojure, Groovy, and Scala. Java syntax borrows heavily from C and C++, but object-oriented features are modeled after Smalltalk and Objective-C. Java eschews certain low-level constructs such as pointers and has a very simple memory model where objects are allocated on the heap (while some implementations e.g. all currently supported by Oracle, may use escape analysis optimization to allocate on the stack instead) and all variables of object types are references. Memory management is handled through integrated automatic garbage collection performed by the JVM.
Latest version
The latest version is Java 21, a long-term support (LTS) version released in September 2023, while Java 17 released in September 2021 is also supported, one of a few older LTS releases down to Java 8 LTS. As an open source platform, Java has many distributors, including Amazon, IBM, Azul Systems, and AdoptOpenJDK. Distributions include Amazon Corretto, Zulu, AdoptOpenJDK, and Liberica. Regarding Oracle, it distributes Java 8, and also makes available e.g. Java 11, both also currently supported LTS versions. Oracle (and others) "highly recomme
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https://en.wikipedia.org/wiki/Eukaryotic%20chromosome%20structure
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Eukaryotic chromosome structure refers to the levels of packaging from raw DNA molecules to the chromosomal structures seen during metaphase in mitosis or meiosis. Chromosomes contain long strands of DNA containing genetic information. Compared to prokaryotic chromosomes, eukaryotic chromosomes are much larger in size and are linear chromosomes. Eukaryotic chromosomes are also stored in the cell nucleus, while chromosomes of prokaryotic cells are not stored in a nucleus. Eukaryotic chromosomes require a higher level of packaging to condense the DNA molecules into the cell nucleus because of the larger amount of DNA. This level of packaging includes the wrapping of DNA around proteins called histones in order to form condensed nucleosomes.
History
The double helix was discovered in 1953 by James Watson and Francis Crick. Other researchers made very important, but unconnected findings about the composition of DNA. Ultimately it was Watson and Crick who put all of these findings together to come up with a model for DNA. Later, chemist Alexander Todd determined that the backbone of a DNA molecule contained repeating phosphate and deoxyribose sugar groups. The biochemist Erwin Chargaff found that adenine and thymine always paired while cytosine and guanine always paired. High resolution X-ray images of DNA that were obtained by Maurice Wilkins and Rosalind Franklin suggested a helical, or corkscrew like shape. Some of the first scientists to recognize the structures now known as chromosomes were Schleiden, Virchow, and Bütschli. The term was coined by Heinrich Wilhelm Gottfried von Waldeyer-Hartz, referring to the term chromatin, was introduced by Walther Flemming. Scientists also discovered plant and animal cells have a central compartment called the nucleus. They soon realized chromosomes were found inside the nucleus and contained different information for many different traits.
Structure
In eukaryotes, such as humans, roughly 3.2 billion nucleotides are spread out
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https://en.wikipedia.org/wiki/Nothing%20Like%20the%20Rain
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"Nothing Like the Rain" is a song recorded by Belgian/Dutch Eurodance band 2 Unlimited. It was released on 10 June 1995 as the fourth and final single from their third album, Real Things (1994). The song was written by co-producers Phil Wilde and Peter Bauwens with Michael Leahy. In the US, it was released as a double a-side single with the European hit single "Here I Go". It peaked within the top 20 in at least four countries, and was also the first single by 2 Unlimited that was a pop-ballad. The single was not released in the UK. Its music video was directed by Nigel Simpkiss, who had previously directed several videos for the band.
Chart performance
"Nothing Like the Rain" was a moderate success on the charts in Europe, entering the top 10 in the band's native Netherlands, peaking at number six. Additionally, it entered the top 20 in Finland (18), Norway (17) and Spain (14), while it reached the top 30 in Belgium (23). On the Eurochart Hot 100, the single peaked at number 68. It was the first 2 Unlimited single to not receive a UK release, and did not chart on the UK Singles Chart. Outside Europe, "Nothing Like the Rain" peaked at number 134 in Australia.
Critical reception
Pop Rescue called the song "brilliant", describing it as "a slow, gentle, beautiful ballad, and it really gives Anita the room to show off her vocals."
Music video
The accompanying music video for "Nothing Like The Rain" was directed by Nigel Simpkiss and was released in the UK in June 1995. It features Anita and Ray performing in front of or behind raining water. Other shots are made in a swimming pool. Simpkiss also directed the music videos for "Let the Beat Control Your Body", "The Real Thing" and "Here I Go". "Nothing Like the Rain" was later published on 2 Unlimited's official YouTube channel in July 2014.
Ballads
2 Unlimited included ballads at the end of their three first studio albums:
"Desire" and "Eternally Yours" on Get Ready!
"Where Are You Now" and "Shelter For A Rainy Day
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https://en.wikipedia.org/wiki/Reverse%20echo
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Reverse echo and reverse reverb are sound effects created as the result of recording an echo or reverb effect of an audio recording played backwards. The original recording is then played forwards accompanied by the recording of the echoed or reverberated signal which now precedes the original signal. The process produces a swelling effect preceding and during playback.
Development
Guitarist and producer Jimmy Page claims to have invented the effect, stating that he originally developed the method when recording the single "Ten Little Indians" with The Yardbirds in 1967. He later used it on a number of Led Zeppelin tracks, including "You Shook Me", "Whole Lotta Love", and their cover of "When the Levee Breaks". In an interview he gave to Guitar World magazine in 1993, Page explained:
Despite Page's claims, an earlier example of the effect is possibly heard towards the end of the 1966 Lee Mallory single "That's the Way It's Gonna Be", produced by Curt Boettcher.
Usage in music
Jimmy Page of Led Zeppelin used this effect in the bridge of "Whole Lotta Love” (1969). Another early example is found in "Alucard" from the eponymous Gentle Giant album (1970), although usage was somewhat common throughout the 1970s, for example in “Crying to the Sky” by Be-Bop Deluxe.
Reverse reverb is commonly used in shoegaze, particularly by such bands as My Bloody Valentine and Spacemen 3.
It is also often used as a lead-in to vocal passages in hardstyle music, and various forms of EDM and pop music. The reverse reverb is applied to the first word or syllable of the vocal for a build-up effect or other-worldly sound.
Metallica used the effect in the song "Fade To Black" on James Hetfield's vocals in their 1984 album Ride The Lightning. The effect was also employed by Genesis (on Phil Collins’ snare drum) at the end of the song “Deep in the Motherload” on the 1978 album “And Then There Were Three”.
Use in other media
Reverse reverb has been used in filmmaking and television produc
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https://en.wikipedia.org/wiki/Monotone%20class%20theorem
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In measure theory and probability, the monotone class theorem connects monotone classes and -algebras. The theorem says that the smallest monotone class containing an algebra of sets is precisely the smallest -algebra containing It is used as a type of transfinite induction to prove many other theorems, such as Fubini's theorem.
Definition of a monotone class
A is a family (i.e. class) of sets that is closed under countable monotone unions and also under countable monotone intersections. Explicitly, this means has the following properties:
if and then and
if and then
Monotone class theorem for sets
Monotone class theorem for functions
Proof
The following argument originates in Rick Durrett's Probability: Theory and Examples.
Results and applications
As a corollary, if is a ring of sets, then the smallest monotone class containing it coincides with the -ring of
By invoking this theorem, one can use monotone classes to help verify that a certain collection of subsets is a -algebra.
The monotone class theorem for functions can be a powerful tool that allows statements about particularly simple classes of functions to be generalized to arbitrary bounded and measurable functions.
See also
Citations
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https://en.wikipedia.org/wiki/Importer%20%28computing%29
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An importer is a software application that reads in a data file or metadata information in one format and converts it to another format via special algorithms (such as filters). An importer often is not an entire program by itself, but an extension to another program, implemented as a plug-in. When implemented in this way, the importer reads the data from the file and converts it into the hosting application's native format.
For example, the data file for a 3D model may be written from a modeler, such as 3D Studio Max. A game developer may then want to use that model in their game's editor. An importer, part of the editor, may read in the 3D Studio Max model and convert it to the game's native format so it can be used in game levels.
Importers are important tools in the video game industry. A plug-in or application that does the converse of an importer is called an exporter.
See also
Data scraping
Web scraping
Report mining
Mashup (web application hybrid)
Metadata
Comparison of feed aggregators
Video game development
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https://en.wikipedia.org/wiki/Alexandru%20Ghika
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Alexandru Ghika (June 22, 1902 – April 11, 1964) was a Romanian mathematician, founder of the Romanian school of functional analysis.
Life
He was born in Bucharest, into the Ghica family, the son of Ioan Ghika (1873–1949) and Elena Metaxa (1870–1951), and great-great-grandson of Grigore IV Ghica, Prince of Wallachia. He started his secondary studies at the Gheorghe Lazăr High School in Bucharest. In 1917, he left with his family for Paris, completing his secondary studies at the Lycée Louis-le-Grand in 1920. He then entered the University of Paris (the Sorbonne) with a major in mathematics, graduating in 1922. In 1929, he obtained a Ph.D. in mathematics from the Faculté des Sciences of the University of Paris.
After completing his doctorate, Ghika returned to Romania. In November 1932 he became assistant professor in the Mathematics Department of the University of Bucharest, working in the Function Theory section chaired by Dimitrie Pompeiu. On February 7, 1935, he was promoted to associate professor, and in 1945 he was named Full Professor and chair of the newly founded Functional Analysis section.
In 1935, Ghika was elected corresponding member of the Romania Academy of Sciences, being promoted to full member in 1938. In 1955 he became corresponding member of the Romanian Academy, and was promoted to full membership on March 20, 1963. In 1949, at the founding of the Institute of Mathematics of the Romanian Academy, he became the chair of the Functional Analysis section of that Institute, a position he held till his death.
Ghika married Elisabeta Angelescu (daughter of one-time Prime Minister Constantin Angelescu) on June 7, 1934. They had a son, Grigore (born November 7, 1936), who became a researcher at the Institute of Atomic Physics in Măgurele.
Alexandru Ghika died in Bucharest of lung cancer. He was buried at the Ghika-Tei church, founded in 1833 by Prince Grigore Alexandru Ghica.
In March, 2007, the heirs of the Ghika and Angelescu families won b
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https://en.wikipedia.org/wiki/Exporter%20%28computing%29
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An exporter is a software application that writes out a data file in a format different from its native format. It does this via special algorithms (such as filters). An exporter often is not an entire program by itself, but an extension to another program, implemented as a plug-in. When implemented in this way, the exporter converts the hosting application's native format into the desired format and writes it to the file.
For example, a 3D model may be written with a modeler, such as 3D Studio Max. A game developer may want to use that model in its game, but uses a custom format that is different from 3D Studio Max's native format. Using the exporter, the model can be saved in the developer's native format and then read into the game (or a tool) without any extra conversion. Using exporters, game tools can also export from their native format into formats for other applications (such as the modeler or a paint program, such as Photoshop).
Exporters are important tools in the video game industry. A plug-in or application that does the converse of an exporter is called an importer. Importers and exporters are often used in conjunction with one another in many software development environments.
Video game development
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https://en.wikipedia.org/wiki/Cycle%20index
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In combinatorial mathematics a cycle index is a polynomial in several variables which is structured in such a way that information about how a group of permutations acts on a set can be simply read off from the coefficients and exponents. This compact way of storing information in an algebraic form is frequently used in combinatorial enumeration.
Each permutation π of a finite set of objects partitions that set into cycles; the cycle index monomial of π is a monomial in variables a1, a2, … that describes the cycle type of this partition: the exponent of ai is the number of cycles of π of size i. The cycle index polynomial of a permutation group is the average of the cycle index monomials of its elements. The phrase cycle indicator is also sometimes used in place of cycle index.
Knowing the cycle index polynomial of a permutation group, one can enumerate equivalence classes due to the group's action. This is the main ingredient in the Pólya enumeration theorem. Performing formal algebraic and differential operations on these polynomials and then interpreting the results combinatorially lies at the core of species theory.
Permutation groups and group actions
A bijective map from a set X onto itself is called a permutation of X, and the set of all permutations of X forms a group under the composition of mappings, called the symmetric group of X, and denoted Sym(X). Every subgroup of Sym(X) is called a permutation group of degree |X|. Let G be an abstract group with a group homomorphism φ from G into Sym(X). The image, φ(G), is a permutation group. The group homomorphism can be thought of as a means for permitting the group G to "act" on the set X (using the permutations associated with the elements of G). Such a group homomorphism is formally called a group action and the image of the homomorphism is a permutation representation of G. A given group can have many different permutation representations, corresponding to different actions.
Suppose that group G acts on
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https://en.wikipedia.org/wiki/Circumscriptional%20name
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In biological classification, circumscriptional names are taxon names that are not ruled by ICZN and are defined by the particular set of members included. Circumscriptional names are used mainly for taxa above family-group level (e. g. order or class), but can be also used for taxa of any ranks, as well as for rank-less taxa.
Non-typified names other than those of the genus- or species-group constitute the majority of generally accepted names of taxa higher than superfamily. The ICZN regulates names of taxa up to family group rank (i. e. superfamily). There are no generally accepted rules of naming higher taxa (orders, classes, phyla, etc.). Under the approach of circumscription-based (circumscriptional) nomenclatures, a circumscriptional name is associated with a certain circumscription of a taxon without regard of its rank or position.
Some authors advocate introducing a mandatory standardized typified nomenclature of higher taxa. They suggest all names of higher taxa to be derived in the same manner as family-group names, i.e. by modifying names of type genera with endings to reflect the rank. There is no consensus on what such higher rank endings should be. A number of established practices exist as to the use of typified names of higher taxa, depending on animal group.
See also
Descriptive botanical name, optional forms still used in botany for ranks above family and for a few family names
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https://en.wikipedia.org/wiki/Variable%20air%20volume
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Variable air volume (VAV) is a type of heating, ventilating, and/or air-conditioning (HVAC) system. Unlike constant air volume (CAV) systems, which supply a constant airflow at a variable temperature, VAV systems vary the airflow at a constant or varying temperature. The advantages of VAV systems over constant-volume systems include more precise temperature control, reduced compressor wear, lower energy consumption by system fans, less fan noise, and additional passive dehumidification.
Box technology
The most simple form of a VAV box is the single duct terminal configuration, which is connected to a single supply air duct that delivers treated air from an air-handling unit (AHU) to the space the box is serving. This configuration can deliver air at variable temperatures or air volumes to meet the heating and cooling loads as well as the ventilation rates required by the space.
Most commonly, VAV boxes are pressure independent, meaning the VAV box uses controls to deliver a constant flow rate regardless of variations in system pressures experienced at the VAV inlet. This is accomplished by an airflow sensor that is placed at the VAV inlet which opens or closes the damper within the VAV box to adjust the airflow. The difference between a CAV and VAV box is that a VAV box can be programmed to modulate between different flowrate setpoints depending on the conditions of the space. The VAV box is programmed to operate between a minimum and maximum airflow setpoint and can modulate the flow of air depending on occupancy, temperature, or other control parameters. A CAV box can only operate between a constant, maximum value, or an “off” state. This difference means the VAV box can provide tighter space temperature control while using much less energy. Another reason why VAV boxes save more energy is that they are coupled with variable-speed drives on fans, so the fans can ramp down when the VAV boxes are experiencing part load conditions.
It is common for VAV boxes to i
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https://en.wikipedia.org/wiki/CCU%20delivery
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Customer Configuration Updating (CCU) is a software development method for structuring the process of providing customers with new versions of products and updates production. This method is developed by researchers of the Utrecht University.
The delivery phase of the CCU method concerns the process which starts at the moment a product is finished until the actual shipping of the product to the customer.
Introduction to the delivery process
As described in the general entry of CCU, the delivery phase is the second phase of the CCU method. In figure one the CCU method is depicted. The phases of CCU that are not covered in this article are concealed by a transparent grey rectangle.
As can be seen in figure one, the delivery phase is in between the release phase and the deployment phase. A software vendor develops and releases a software product and afterwards it has to be transported to the customer. This phase is the delivery process. This process is highly complex because the vendor often has to deal with a product which has multiple versions, variable features, dependency on external products, and different kinds of distribution options. The CCU method helps the software vendor in structuring this process.
In figure 2, the process-data diagram of the delivery phase within CCU is depicted. This way of modeling was invented by Saeki (2003). On the left side you can see the meta-process model and on the right side the meta-data model. The two models are linked to each other by the relationships visualized as dotted lines. The meta-data model (right side) shows the concepts involved in the process and how the concepts are related to each other. For instance it is visible that a package consists of multiple parts, being the: software package, system description, manual, and license and management information. The numbers between the relations indicate in what quantity the concepts are related. For example the “1..1” between package and software package means that
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https://en.wikipedia.org/wiki/Poincar%C3%A9%20inequality
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In mathematics, the Poincaré inequality is a result in the theory of Sobolev spaces, named after the French mathematician Henri Poincaré. The inequality allows one to obtain bounds on a function using bounds on its derivatives and the geometry of its domain of definition. Such bounds are of great importance in the modern, direct methods of the calculus of variations. A very closely related result is Friedrichs' inequality.
Statement of the inequality
The classical Poincaré inequality
Let p, so that 1 ≤ p < ∞ and Ω a subset bounded at least in one direction. Then there exists a constant C, depending only on Ω and p, so that, for every function u of the Sobolev space W01,p(Ω) of zero-trace (a.k.a. zero on the boundary) functions,
Poincaré–Wirtinger inequality
Assume that 1 ≤ p ≤ ∞ and that Ω is a bounded connected open subset of the n-dimensional Euclidean space ℝn with a Lipschitz boundary (i.e., Ω is a Lipschitz domain). Then there exists a constant C, depending only on Ω and p, such that for every function u in the Sobolev space ,
where
is the average value of u over Ω, with |Ω| standing for the Lebesgue measure of the domain Ω. When Ω is a ball, the above inequality is
called a -Poincaré inequality; for more general domains Ω, the above is more familiarly known as a Sobolev inequality.
The necessity to subtract the average value can be seen by considering constant functions for which the derivative is zero while, without subtracting the average, we can have the integral of the function as large as we wish. There are other conditions instead of subtracting the average that we can require in order to deal with this issue with constant functions, for example, requiring trace zero, or subtracting the average over some proper subset of the domain. The constant C in the Poincare inequality may be different from condition to condition. Also note that the issue is not just the constant functions, because it is the same as saying that adding a constant value to a f
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https://en.wikipedia.org/wiki/XO%20sex-determination%20system
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The XO sex-determination system (sometimes X0 sex-determination system) is a system that some species of insects, arachnids, and mammals use to determine the sex of offspring. In this system, there is only one sex chromosome, referred to as X. Males only have one X chromosome (XO), while females have two (XX). The letter O (sometimes a zero) signifies the lack of a second X. Maternal gametes always contain an X chromosome, so the sex of the animals' offspring depends on whether a sex chromosome is present in the male gamete. Its sperm normally contains either one X chromosome or no sex chromosomes at all.
This system determines the sex of offspring among:
Most arachnids with the exception of mites where a small majority are haplodiploid,
Almost all apterygote and Paleopteran insects (e.g., dragonflies, silverfish)
Most exopterygote insects (e.g., grasshoppers, crickets, cockroaches)
Some nematodes, crustaceans, gastropod molluscs, and bony fish, notably in the genus Ancistrus
Several mammals
A few species of bat, including the hammer-headed bat, Buettikofer's epauletted fruit bat, Franquet's epauletted fruit bat, Peters's epauletted fruit bat, and Gambian epauletted fruit bat
The Ryukyu spiny rat and Tokunoshima spiny rat
In a variant of this system, most individuals have two sex chromosomes (XX) and are hermaphroditic, producing both eggs and sperm with which they can fertilize themselves, while rare individuals are male and have only one sex chromosome (XO). The model organism Caenorhabditis elegans—a nematode frequently used in biological research—is one such organism.
Some Drosophila species have XO males. These are thought to arise via the loss of the Y chromosome.
Evolution
XO sex determination can evolve from XY sex determination within about 2 million years.
Parthenogenesis
Parthenogenesis with XO sex-determination can occur by different mechanisms to produce either male or female offspring.
See also
Sex-determination system
Sexual differen
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https://en.wikipedia.org/wiki/Lesser%20sciatic%20foramen
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The lesser sciatic foramen is an opening (foramen) between the pelvis and the back of the thigh. The foramen is formed by the sacrotuberous ligament which runs between the sacrum and the ischial tuberosity and the sacrospinous ligament which runs between the sacrum and the ischial spine.
Structure
The lesser sciatic foramen has the following boundaries:
Anterior: the tuberosity of the ischium
Superior: the spine of the ischium and sacrospinous ligament
Posterior: the sacrotuberous ligament
Alternatively, the foramen can be defined by the boundaries of the lesser sciatic notch and the two ligaments.
Function
The following pass through the foramen:
the tendon of the obturator internus
internal pudendal vessels
pudendal nerve
nerve to the obturator internus
See also
Greater sciatic foramen
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https://en.wikipedia.org/wiki/ZW%20sex-determination%20system
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The ZW sex-determination system is a chromosomal system that determines the sex of offspring in birds, some fish and crustaceans such as the giant river prawn, some insects (including butterflies and moths), the schistosome family of flatworms, and some reptiles, e.g. majority of snakes, lacertid lizards and monitors including Komodo dragons. It is also present in some plants, where it has probably evolved independently on several occasions. The letters Z and W are used to distinguish this system from the XY sex-determination system. In the ZW system, females have a pair of dissimilar ZW chromosomes, and males have two similar ZZ chromosomes.
In contrast to the XY sex-determination system and the X0 sex-determination system, where the sperm determines the sex, in the ZW system, the ovum determines the sex of the offspring. Males are the homogametic sex (ZZ), while females are the heterogametic sex (ZW). The Z chromosome is larger and has more genes, like the X chromosome in the XY system.
Significance of the ZW and XY systems
No genes are shared between the avian ZW and mammalian XY chromosomes, and, from a comparison between chicken and human, the Z chromosome appears similar to the autosomal chromosome 9 in humans. It has been proposed that the ZW and XY sex determination systems do not share an origin but that the sex chromosomes are derived from autosomal chromosomes of the common ancestor. These autosomes are thought to have evolved sex-determining loci that eventually developed into the respective sex chromosomes once the recombination between the chromosomes (X and Y or Z and W) was suppressed.
The platypus, a monotreme mammal, has a system of five pairs of XY chromosomes. They form a multiple chain due to homologous regions in male meiosis and finally segregates into XXXXX-sperm and YYYYY-sperm. The bird Z-like pair shows up on opposite ends of the chain. Areas homologous to the bird Z chromosome are scattered throughout X3 and X5. Although the sex-deter
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https://en.wikipedia.org/wiki/Haplodiploidy
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Haplodiploidy is a sex-determination system in which males develop from unfertilized eggs and are haploid, and females develop from fertilized eggs and are diploid. Haplodiploidy is sometimes called arrhenotoky.
Haplodiploidy determines the sex in all members of the insect orders Hymenoptera (bees, ants, and wasps) and Thysanoptera ('thrips'). The system also occurs sporadically in some spider mites, Hemiptera, Coleoptera (bark beetles), and rotifers.
In this system, sex is determined by the number of sets of chromosomes an individual receives. An offspring formed from the union of a sperm and an egg develops as a female, and an unfertilized egg develops as a male. This means that the males have half the number of chromosomes that a female has, and are haploid.
The haplodiploid sex-determination system has a number of peculiarities. For example, a male has no father and cannot have sons, but he has a grandfather and can have grandsons. Additionally, if a eusocial-insect colony has only one queen, and she has only mated once, then the relatedness between workers (diploid females) in a hive or nest is . This means the workers in such monogamous single-queen colonies are significantly more closely related than in other sex determination systems where the relatedness of siblings is usually no more than . It is this point which drives the kin selection theory of how eusociality evolved. Whether haplodiploidy did in fact pave the way for the evolution of eusociality is still a matter of debate.
Another feature of the haplodiploidy system is that recessive lethal and deleterious alleles will be removed from the population rapidly because they will automatically be expressed in the males (dominant lethal and deleterious alleles are removed from the population every time they arise, as they kill any individual they arise in).
Haplodiploidy is not the same thing as an X0 sex-determination system. In haplodiploidy, males receive one half of the chromosomes that females r
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https://en.wikipedia.org/wiki/Wavelet%20modulation
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Wavelet modulation, also known as fractal modulation, is a modulation technique that makes use of wavelet transformations to represent the data being transmitted. One of the objectives of this type of modulation is to send data at multiple rates over a channel that is unknown. If the channel is not clear for one specific bit rate, meaning that the signal will not be received, the signal can be sent at a different bit rate where the signal-to-noise ratio is higher.
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https://en.wikipedia.org/wiki/Enumerated%20type
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In computer programming, an enumerated type (also called enumeration, enum, or factor in the R programming language, and a categorical variable in statistics) is a data type consisting of a set of named values called elements, members, enumeral, or enumerators of the type. The enumerator names are usually identifiers that behave as constants in the language. An enumerated type can be seen as a degenerate tagged union of unit type. A variable that has been declared as having an enumerated type can be assigned any of the enumerators as a value. In other words, an enumerated type has values that are different from each other, and that can be compared and assigned, but are not specified by the programmer as having any particular concrete representation in the computer's memory; compilers and interpreters can represent them arbitrarily.
For example, the four suits in a deck of playing cards may be four enumerators named Club, Diamond, Heart, and Spade, belonging to an enumerated type named suit. If a variable V is declared having suit as its data type, one can assign any of those four values to it.
Although the enumerators are usually distinct, some languages may allow the same enumerator to be listed twice in the type's declaration. The names of enumerators need not be semantically complete or compatible in any sense. For example, an enumerated type called color may be defined to consist of the enumerators Red, Green, Zebra, Missing, and Bacon. In some languages, the declaration of an enumerated type also intentionally defines an ordering of its members (High, Medium and Low priorities); in others, the enumerators are unordered (English, French, German and Spanish supported languages); in others still, an implicit ordering arises from the compiler concretely representing enumerators as integers.
Some enumerator types may be built into the language. The Boolean type, for example is often a pre-defined enumeration of the values False and True. A unit type consisting
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https://en.wikipedia.org/wiki/Eukaryotic%20chromosome%20fine%20structure
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Eukaryotic chromosome fine structure refers to the structure of sequences for eukaryotic chromosomes. Some fine sequences are included in more than one class, so the classification listed is not intended to be completely separate.
Chromosomal characteristics
Some sequences are required for a properly functioning chromosome:
Centromere: Used during cell division as the attachment point for the spindle fibers.
Telomere: Used to maintain chromosomal integrity by capping off the ends of the linear chromosomes. This region is a microsatellite, but its function is more specific than a simple tandem repeat.
Throughout the eukaryotic kingdom, the overall structure of chromosome ends is conserved and is characterized by the telomeric tract - a series of short G-rich repeats. This is succeeded by an extensive subtelomeric region consisting of various types and lengths of repeats - the telomere associated sequences (TAS). These regions are generally low in gene density, low in transcription, low in recombination, late replicating, are involved in protecting the end from degradation and end-to-end fusions and in completing replication. The subtelomeric repeats can rescue chromosome ends when telomerase fails, buffer subtelomerically located genes against transcriptional silencing and protect the genome from deleterious rearrangements due to ectopic recombination. They may also be involved in fillers for increasing chromosome size to some minimum threshold level necessary for chromosome stability; act as barriers against transcriptional silencing; provide a location for the adaptive amplification of genes; and be involved in secondary mechanism of telomere maintenance via recombination when telomerase activity is absent.
Structural sequences
Other sequences are used in replication or during interphase with the physical structure of the chromosome.
Ori, or Origin: Origins of replication.
MAR: Matrix attachment regions, where the DNA attaches to the nuclear matrix.
Prote
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https://en.wikipedia.org/wiki/%CE%9BProlog
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λProlog, also written lambda Prolog, is a logic programming language featuring polymorphic typing, modular programming, and higher-order programming. These extensions to Prolog are derived from the higher-order hereditary Harrop formulas used to justify the foundations of λProlog. Higher-order quantification, simply typed λ-terms, and higher-order unification gives λProlog the basic supports needed to capture the λ-tree syntax approach to higher-order abstract syntax, an approach to representing syntax that maps object-level bindings to programming language bindings. Programmers in λProlog need not deal with bound variable names: instead various declarative devices are available to deal with binder scopes and their instantiations.
History
Since 1986, λProlog has received numerous implementations. As of 2023, the language and its implementations are still actively being developed.
The Abella theorem prover has been designed to provide an interactive environment for proving theorems about the declarative core of λProlog.
See also
Curry's paradox#Lambda calculus — about inconsistency problems caused by combining (propositional) logic and untyped lambda calculus
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https://en.wikipedia.org/wiki/Firefly%20luciferase
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Firefly luciferase is the light-emitting enzyme responsible for the bioluminescence of fireflies and click beetles. The enzyme catalyses the oxidation of firefly luciferin, requiring oxygen and ATP. Because of the requirement of ATP, firefly luciferases have been used extensively in biotechnology.
Mechanism of reaction
The chemical reaction catalyzed by firefly luciferase takes place in two steps:
luciferin + ATP → luciferyl adenylate + PPi
luciferyl adenylate + O2 → oxyluciferin + AMP + light
Light is produced because the reaction forms oxyluciferin in an electronically excited state. The reaction releases a photon of light as oxyluciferin goes back to the ground state.
Luciferyl adenylate can additionally participate in a side reaction with O2 to form hydrogen peroxide and dehydroluciferyl-AMP. About 20% of the luciferyl adenylate intermediate is oxidized in this pathway.
Firefly luciferase generates light from luciferin in a multistep process. First, D-luciferin is adenylated by MgATP to form luciferyl adenylate and pyrophosphate. After activation by ATP, luciferyl adenylate is oxidized by molecular oxygen to form a dioxetanone ring. A decarboxylation reaction forms an excited state of oxyluciferin, which tautomerizes between the keto-enol form. The reaction finally emits light as oxyluciferin returns to the ground state.
Bifunctionality
Luciferase can function in two different pathways: a bioluminescence pathway and a CoA-ligase pathway. In both pathways, luciferase initially catalyzes an adenylation reaction with MgATP. However, in the CoA-ligase pathway, CoA can displace AMP to form luciferyl CoA.
Fatty acyl-CoA synthetase similarly activates fatty acids with ATP, followed by displacement of AMP with CoA. Because of their similar activities, luciferase is able to replace fatty acyl-CoA synthetase and convert long-chain fatty acids into fatty-acyl CoA for beta oxidation.
Structure
The protein structure of firefly luciferase consists of two comp
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https://en.wikipedia.org/wiki/Critical%20points%20of%20the%20elements%20%28data%20page%29
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Critical point
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https://en.wikipedia.org/wiki/Stamp%20mill
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A stamp mill (or stamp battery or stamping mill) is a type of mill machine that crushes material by pounding rather than grinding, either for further processing or for extraction of metallic ores. Breaking material down is a type of unit operation.
Description
A stamp mill consists of a set of heavy steel (iron-shod wood in some cases) stamps, loosely held vertically in a frame, in which the stamps can slide up and down. They are lifted by cams on a horizontal rotating shaft. As the cam moves from under the stamp, the stamp falls onto the ore below, crushing the rock, and the lifting process is repeated at the next pass of the cam.
Each one frame and stamp set is sometimes called a "battery" or, confusingly, a "stamp" and mills are sometimes categorised by how many stamps they have, i.e. a "10 stamp mill" has 10 sets. They usually are arranged linearly, but when a mill is enlarged, a new line of them may be constructed rather than extending the line. Abandoned mill sites (as documented by industrial archaeologists) will usually have linear rows of foundation sets as their most prominent visible feature as the overall apparatus can exceed 20 feet in height, requiring large foundations. Stamps are usually arranged in sets of five.
Some ore processing applications used large quantities of water so some stamp mills are located near natural or artificial bodies of water. For example, the Redridge Steel Dam was built to supply stamp mills with process water. The California Stamp made its major debut at the 1894 San Francisco midsummer fair. It was the first type that generated electricity, powered by a wood feed steam boiler. Steam started the wheels and belts turning; a generator that also was steam driven supplied the electricity for overhead lighting. This was a big plus for mining company, enabling more production time.
History
The main components for water-powered stamp mills – water wheels, cams, and hammers – were known in the Hellenistic era in the Eastern
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https://en.wikipedia.org/wiki/DOD-STD-2167A
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DOD-STD-2167A (Department of Defense Standard 2167A), titled "Defense Systems Software Development", was a United States defense standard, published on February 29, 1988, which updated the less well known DOD-STD-2167 published 4 June 1985. This document established "uniform requirements for the software development that are applicable throughout the system life cycle." This revision was written to allow the contractor more flexibility and was a significant reorganization and reduction of the previous revision; e.g.., where the previous revision prescribed pages of design and coding standards, this revision only gave one page of general requirements for the contractor's coding standards; while DOD-STD-2167 listed 11 quality factors to be addressed for each software component in the SRS, DOD-STD-2167A only tasked the contractor to address relevant quality factors in the SRS. Like DOD-STD-2167, it was designed to be used with DOD-STD-2168, "Defense System Software Quality Program".
On December 5, 1994 it was superseded by MIL-STD-498, which merged DOD-STD-2167A, DOD-STD-7935A, and DOD-STD-2168 into a single document, and addressed some vendor criticisms.
Criticism
One criticism of the standard was that it was biased toward the Waterfall Model. Although the document states "the contractor is responsible for selecting software development methods (for example, rapid prototyping)", it also required "formal reviews and audits" that seemed to lock the vendor into designing and documenting the system before any implementation began.
Another criticism was the focus on design documents, to the exclusion of Computer-Aided Software Engineering (CASE) tools being used in the industry. Vendors would often use the CASE tools to design the software, then write several standards-required documents to describe the CASE-formatted data. This created problems matching design documents to the actual product.
Predecessors
DOD-STD-2167 and DOD-STD-2168 (often mistakenly referred to a
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https://en.wikipedia.org/wiki/Frege%27s%20theorem
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In metalogic and metamathematics, Frege's theorem is a metatheorem that states that the Peano axioms of arithmetic can be derived in second-order logic from Hume's principle. It was first proven, informally, by Gottlob Frege in his 1884 Die Grundlagen der Arithmetik (The Foundations of Arithmetic) and proven more formally in his 1893 Grundgesetze der Arithmetik I (Basic Laws of Arithmetic I). The theorem was re-discovered by Crispin Wright in the early 1980s and has since been the focus of significant work. It is at the core of the philosophy of mathematics known as neo-logicism (at least of the Scottish School variety).
Overview
In The Foundations of Arithmetic (1884), and later, in Basic Laws of Arithmetic (vol. 1, 1893; vol. 2, 1903), Frege attempted to derive all of the laws of arithmetic from axioms he asserted as logical (see logicism). Most of these axioms were carried over from his Begriffsschrift; the one truly new principle was one he called the Basic Law V (now known as the axiom schema of unrestricted comprehension): the "value-range" of the function f(x) is the same as the "value-range" of the function g(x) if and only if ∀x[f(x) = g(x)]. However, not only did Basic Law V fail to be a logical proposition, but the resulting system proved to be inconsistent, because it was subject to Russell's paradox.
The inconsistency in Frege's Grundgesetze overshadowed Frege's achievement: according to Edward Zalta, the Grundgesetze "contains all the essential steps of a valid proof (in second-order logic) of the fundamental propositions of arithmetic from a single consistent principle." This achievement has become known as Frege's theorem.
Frege's theorem in propositional logic
In propositional logic, Frege's theorem refers to this tautology:
(P → (Q→R)) → ((P→Q) → (P→R))
The theorem already holds in one of the weakest logics imaginable, the constructive implicational calculus. The proof under the Brouwer–Heyting–Kolmogorov interpretation reads .
In words:
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https://en.wikipedia.org/wiki/Extragalactic%20background%20light
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The diffuse extragalactic background light (EBL) is all the accumulated radiation in the universe due to star formation processes, plus a contribution from active galactic nuclei (AGNs). This radiation covers almost all wavelengths of the electromagnetic spectrum, except the microwave, which is dominated by the primordial cosmic microwave background. The EBL is part of the diffuse extragalactic background radiation (DEBRA), which by definition covers the entire electromagnetic spectrum. After the cosmic microwave background, the EBL produces the second-most energetic diffuse background, thus being essential for understanding the full energy balance of the universe.
The understanding of the EBL is also fundamental for extragalactic very-high-energy (VHE, 30 GeV-30 TeV) astronomy. VHE photons coming from cosmological distances are attenuated by pair production with EBL photons. This interaction is dependent on the spectral energy distribution (SED) of the EBL. Therefore, it is necessary to know the SED of the EBL in order to study intrinsic properties of the emission in the VHE sources.
Observations
The direct measurement of the EBL is difficult mainly due to the contribution of zodiacal light that is orders of magnitude higher than the EBL. Different groups have claimed the detection of the EBL in the optical and near-infrared. However, it has been proposed that these analyses have been contaminated by zodiacal light. Recently, two independent groups using different technique have claimed the detection of the EBL in the optical with no contamination from zodiacal light.
There are also other techniques that set limits to the background. It is possible to set lower limits from deep galaxy surveys. On the other hand, VHE observations of extragalactic sources set upper limits to the EBL.
In November 2018, astronomers reported that the EBL amounted to photons.
Empirical modelings
There are empirical approaches that predict the overall SED of the EBL in the local uni
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https://en.wikipedia.org/wiki/Axial%20multipole%20moments
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Axial multipole moments are a series expansion of the electric potential of a charge distribution localized close to the origin along one Cartesian axis, denoted here as the z-axis. However, the axial multipole expansion can also be applied to any potential or field that varies inversely with the distance to the source, i.e., as . For clarity, we first illustrate the expansion for a single point charge, then generalize to an arbitrary charge density localized to the z-axis.
Axial multipole moments of a point charge
The electric potential of a point charge q located on the z-axis at (Fig. 1) equals
If the radius r of the observation point is greater than a, we may factor out and expand the square root in powers of using Legendre polynomials
where the axial multipole moments contain everything specific to a given charge distribution; the other parts of the electric potential depend only on the coordinates of the observation point P. Special cases include the axial monopole moment , the axial dipole moment and the axial quadrupole moment . This illustrates the general theorem that the lowest non-zero multipole moment is independent of the origin of the coordinate system, but higher multipole moments are not (in general).
Conversely, if the radius r is less than a, we may factor out and expand in powers of , once again using Legendre polynomials
where the interior axial multipole moments contain everything specific to a given charge distribution; the other parts depend only on the coordinates of the observation point P.
General axial multipole moments
To get the general axial multipole moments, we replace the point charge of the previous section with an infinitesimal charge element , where represents the charge density at position on the z-axis. If the radius r of the observation point P is greater than the largest for which is significant (denoted ), the electric potential may be written
where the axial multipole moments are defined
Special
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https://en.wikipedia.org/wiki/Synchronization%20%28computer%20science%29
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In computer science, synchronization is the task of coordinating multiple of processes to join up or handshake at a certain point, in order to reach an agreement or commit to a certain sequence of action.
Motivation
The need for synchronization does not arise merely in multi-processor systems but for any kind of concurrent processes; even in single processor systems. Mentioned below are some of the main needs for synchronization:
Forks and Joins: When a job arrives at a fork point, it is split into N sub-jobs which are then serviced by n tasks. After being serviced, each sub-job waits until all other sub-jobs are done processing. Then, they are joined again and leave the system. Thus, parallel programming requires synchronization as all the parallel processes wait for several other processes to occur.
Producer-Consumer: In a producer-consumer relationship, the consumer process is dependent on the producer process until the necessary data has been produced.
Exclusive use resources: When multiple processes are dependent on a resource and they need to access it at the same time, the operating system needs to ensure that only one processor accesses it at a given point in time. This reduces concurrency.
Requirements
Thread synchronization is defined as a mechanism which ensures that two or more concurrent processes or threads do not simultaneously execute some particular program segment known as critical section. Processes' access to critical section is controlled by using synchronization techniques. When one thread starts executing the critical section (serialized segment of the program) the other thread should wait until the first thread finishes. If proper synchronization techniques are not applied, it may cause a race condition where the values of variables may be unpredictable and vary depending on the timings of context switches of the processes or threads.
For example, suppose that there are three processes, namely 1, 2, and 3. All three of them are concu
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