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https://en.wikipedia.org/wiki/D%27Alembert%20operator | In special relativity, electromagnetism and wave theory, the d'Alembert operator (denoted by a box: ), also called the d'Alembertian, wave operator, box operator or sometimes quabla operator (cf. nabla symbol) is the Laplace operator of Minkowski space. The operator is named after French mathematician and physicist Jean le Rond d'Alembert.
In Minkowski space, in standard coordinates , it has the form
Here is the 3-dimensional Laplacian and is the inverse Minkowski metric with
, , for .
Note that the and summation indices range from 0 to 3: see Einstein notation. We have assumed units such that the speed of light = 1.
(Some authors alternatively use the negative metric signature of , with .)
Lorentz transformations leave the Minkowski metric invariant, so the d'Alembertian yields a Lorentz scalar. The above coordinate expressions remain valid for the standard coordinates in every inertial frame.
The box symbol and alternate notations
There are a variety of notations for the d'Alembertian. The most common are the box symbol (Unicode: ) whose four sides represent the four dimensions of space-time and the box-squared symbol which emphasizes the scalar property through the squared term (much like the Laplacian). In keeping with the triangular notation for the Laplacian, sometimes is used.
Another way to write the d'Alembertian in flat standard coordinates is . This notation is used extensively in quantum field theory, where partial derivatives are usually indexed, so the lack of an index with the squared partial derivative signals the presence of the d'Alembertian.
Sometimes the box symbol is used to represent the four-dimensional Levi-Civita covariant derivative. The symbol is then used to represent the space derivatives, but this is coordinate chart dependent.
Applications
The wave equation for small vibrations is of the form
where is the displacement.
The wave equation for the electromagnetic field in vacuum is
where is the electromagn |
https://en.wikipedia.org/wiki/List%20of%20common%20astronomy%20symbols | This is a compilation of symbols commonly used in astronomy, particularly professional astronomy.
Age (stellar)
τ - age
Astrometry parameters
Astrometry parameters
Rv - radial velocity
cz - apparent radial velocity
z - Redshift
μ - proper motion
π - parallax
J - epoch
α - Right Ascension
δ - Declination
λ - Ecliptic longitude
β - Ecliptic latitude
l - Galactic longitude
b - Galactic latitude
Cosmological parameters
Cosmological parameters
h - dimensionless Hubble parameter
H0 - Hubble constant
Λ - cosmological constant
Ω - density parameter
ρ - density
ρc - critical density
z - redshift
Distance description
Distance description for orbital and non-orbital parameters:
d - distance
d - in km = kilometer
d - in mi = mile
d - in AU = astronomical unit
d - in ly = light-year
d - in pc = parsec
d - in kpc = kiloparsec (1000 pc)
DL - luminosity distance, obtaining an objects distance using only visual aspects
Galaxy comparison
Galaxy type and spectral comparison:
see galaxy morphological classification
Luminosity comparison
Luminosity comparison:
LS, - luminosity of the Sun (Sol)
Luminosity of certain object:
Lacc - accretion luminosity
Lbol - bolometric luminosity
Mass comparison
Mass comparison:
ME, - mass of Earth
, - mass of Jupiter
MS, - mass of the Sun (Sol)
Mass of certain object:
M● - mass of black hole
Macc - mass of accretion disc
Metallicity comparison
Metallicity comparison:
[Fe/H] - Ratio of Iron to Hydrogen. This is not an exact ratio, but rather a logarithmic representation of the ratio of a star's iron abundance compared to that of the Sun.
for a given star () : , where the values represent the number densities of the given element.
[M/H] - Metallicity ratio.
Z - Metallicity
Z☉, ZS - Metallicity of the Sun (Sol)
Orbital parameters
Orbital Parameters of a Cosmic Object:
α - RA, right ascension, if the Greek letter does not appear, á letter will appear.
δ - Dec, declination, if the Greek letter does |
https://en.wikipedia.org/wiki/Oxycarboxin | Oxycarboxin is an organic chemical used in agriculture to protect crops from fungal diseases. It was first marketed by Uniroyal in 1969 using their brand name Plantvax. The compound is an anilide which combines a heterocyclic acid with aniline to give an inhibitor of succinate dehydrogenase (SDHI).
Synthesis
Oxyxarboxin was first made by the oxidation of carboxin, as disclosed in patents filed by Uniroyal.
Ethyl 2-chloroacetoacetate is treated with 2-mercaptoethanol and base, followed by cyclisation and water removal under acidic conditions. The resultant ethyl ester of the 1,4-oxathiine heterocycle is then formed into an amide with aniline using standard conditions via the carboxylic acid and acid chloride. This gives carboxin in high overall yield. The synthesis is completed by treatment with 30% hydrogen peroxide in acetic acid.
Mechanism of action
Carboxin and oxycarboxin act by inhibition of succinate dehydrogenase (SDHI): they bind to the quinone reduction site of the enzyme complex, preventing ubiquinone from doing so. As a consequence, the tricarboxylic acid cycle and electron transport chain cannot function.
Uses
Oxycarboxin is used to control rust diseases (e.g. soybean rust) at an application rate of 200–400 g/ha.
History
Oxycarboxin has been commercially available since 1969, when it was introduced under the brand name Plantvax. |
https://en.wikipedia.org/wiki/Endoreversible%20thermodynamics | Endoreversible thermodynamics is a subset of irreversible thermodynamics aimed at making more realistic assumptions about heat transfer than are typically made in reversible thermodynamics. It gives an upper bound on the power that can be derived from a real process that is lower than that predicted by Carnot for a Carnot cycle, and accommodates the exergy destruction occurring as heat is transferred irreversibly.
It is also called finite-time thermodynamics, entropy generation minimization, or thermodynamic optimization.
History
Endoreversible thermodynamics was discovered multiple times, with Reitlinger (1929), Novikov (1957) and Chambadal (1957), although it is most often attributed to Curzon & Ahlborn (1975).
Reitlinger derived it by considering a heat exchanger receiving heat from a finite hot stream fed by a combustion process.
A brief review of the history of rediscoveries is in.
Efficiency at maximal power
Consider a semi-ideal heat engine, in which heat transfer takes time, according to Fourier's law of heat conduction: , but other operations happen instantly.
Its maximal efficiency is the standard Carnot result, but it requires heat transfer to be reversible (quasistatic), thus taking infinite time. At maximum power output, its efficiency is the Chambadal–Novikov efficiency:
Due to occasional confusion about the origins of the above equation, it is sometimes named the Chambadal–Novikov–Curzon–Ahlborn efficiency.
Derivation
This derivation is a slight simplification of Curzon & Ahlborn.
Consider a heat engine, with a single working fluid cycling around the engine. On one side, the working fluid has temperature , and is in direct contact with the hot heat bath. On the other side, it has temperature , and is in direct contact with the cold heat bath.
The heat flow into the engine is , where is the heat conduction coefficient. The heat flow out of the engine is . The power output of the engine is .
Side note: if one cycle of the engine takes |
https://en.wikipedia.org/wiki/Tee%20%28command%29 | In computing, tee is a command in command-line interpreters (shells) using standard streams which reads standard input and writes it to both standard output and one or more files, effectively duplicating its input. It is primarily used in conjunction with pipes and filters. The command is named after the T-splitter used in plumbing.
Overview
The tee command is normally used to split the output of a program so that it can be both displayed and saved in a file. The command can be used to capture intermediate output before the data is altered by another command or program.
The tee command reads standard input, then writes its content to standard output. It simultaneously copies the data into the specified file(s) or variables.
The syntax differs depending on the command's implementation.
Implementations
The command is available for Unix and Unix-like operating systems, Microware OS-9, DOS (e.g. 4DOS, FreeDOS), Microsoft Windows (e.g. 4NT, Windows PowerShell), and ReactOS. The Linux tee command was written by Mike Parker, Richard Stallman, and David MacKenzie. The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities. The FreeDOS version was developed by Jim Hall and is licensed under the GPL.
The command has also been ported to the IBM i operating system.
Additionally the sponge command offers similar capabilities.
Unix and Unix-like
tee [ -a ] [ -i ] [ File ... ]
Arguments:
File ... A list of files, each of which receives the output.
Flags:
-a Appends the output to each file, rather than overwriting it.
-i Ignores interrupts.
The command returns the following exit values (exit status):
0 The standard input was successfully copied to all output files.
>0 An error occurred.
Using process substitution lets more than one process read the standard output of the originating process.
Read this example from GNU Coreutils, tee invocation.
Note: If a write to any suc |
https://en.wikipedia.org/wiki/IBM%20PC%20DOS | IBM PC DOS (commonly called The IBM Personal Computer DOS and IBM DOS), an acronym for IBM Personal Computer Disk Operating System, is a discontinued disk operating system for the IBM Personal Computer, its successors, and IBM PC compatibles. It was manufactured and sold by IBM from the early 1980s into the 2000s. Developed by Microsoft, it was also sold by that company as MS-DOS. Both operating systems were identical or almost identical until 1993, when IBM began selling PC DOS 6.1 with new features. The collective shorthand for PC DOS and MS-DOS was DOS, which is also the generic term for disk operating system, and is shared with dozens of disk operating systems called DOS.
History
The IBM task force assembled to develop the IBM PC decided that critical components of the machine, including the operating system, would come from outside vendors. This radical break from company tradition of in-house development was one of the key decisions that made the IBM PC an industry standard. Microsoft, founded five years earlier by Bill Gates, was eventually selected for the operating system.
IBM wanted Microsoft to retain ownership of whatever software it developed, and wanted nothing to do with helping Microsoft, other than making suggestions from afar. According to task force member Jack Sams:
The reasons were internal. We had a terrible problem being sued by people claiming we had stolen their stuff. It could be horribly expensive for us to have our programmers look at code that belonged to someone else because they would then come back and say we stole it and made all this money. We had lost a series of suits on this, and so we didn't want to have a product which was clearly someone else's product worked on by IBM people. We went to Microsoft on the proposition that we wanted this to be their product.
IBM first contacted Microsoft to look the company over in July 1980. Negotiations continued over the months that followed, and the paperwork was officially signed in ear |
https://en.wikipedia.org/wiki/Phone%20connector%20%28audio%29 | A phone connector, also known as phone jack, audio jack, headphone jack or jack plug, is a family of electrical connectors typically used for analog audio signals. A plug, the "male" connector, is inserted into the jack, the "female" connector.
The phone connector was invented for use in telephone switchboards in the 19th century and is still widely used.
The phone connector is cylindrical in shape, with a grooved tip to retain it. In its original audio configuration, it typically has two, three, four or, occasionally, five contacts. Three-contact versions are known as TRS connectors (tip, ring, sleeve). Ring contacts are typically the same diameter as the sleeve, the long shank. Similarly, two-, four- and five-contact versions are called TS, TRRS and TRRRS connectors respectively. The outside diameter of the "sleeve" conductor is . The "mini" connector has a diameter of and the "sub-mini" connector has a diameter of . The "mini" connector has a length of .
Other terms
Specific models, and connectors used in specific applications, may be termed e.g. stereo plug, headphone jack, microphone jack, aux input, etc. The 3.5 mm versions are mini-phone, mini-stereo, mini jack, etc.
In the UK, jack plug and jack socket are the male and female phone connectors. In the US, a stationary (more fixed) electrical connector is the jack. The terms phone plug and phone jack sometimes refer to different genders of phone connectors, but also sometimes refer to the RJ11 and older telephone plugs and corresponding jacks that connect wired telephones to wall outlets.
Phone plugs and jacks are different from phono plugs and phono jacks (or in the UK, phono socket) which are RCA connectors common in consumer hi-fi and audiovisual equipment. The 3.5 mm connector is, however, sometimes—but counter to the connector manufacturers' nomenclature—referred to as mini phono.
Historical development
Quarter-inch size
Modern phone connectors are available in three standard sizes. The original |
https://en.wikipedia.org/wiki/Genetics%20%28journal%29 | Genetics is a monthly scientific journal publishing investigations bearing on heredity, genetics, biochemistry and molecular biology. Genetics is published by the Genetics Society of America. It has a delayed open access policy, and makes articles available online without a subscription after 12 months have elapsed since first publication. Since 2010, it is published online-only. George Harrison Shull was the founding editor of Genetics in 1916.
Editors-in-Chief |
https://en.wikipedia.org/wiki/Rushbrooke%20inequality | In statistical mechanics, the Rushbrooke inequality relates the critical exponents of a magnetic system which exhibits a first-order phase transition in the thermodynamic limit for non-zero temperature T.
Since the Helmholtz free energy is extensive, the normalization to free energy per site is given as
The magnetization M per site in the thermodynamic limit, depending on the external magnetic field H and temperature T is given by
where is the spin at the i-th site, and the magnetic susceptibility and specific heat at constant temperature and field are given by, respectively
and
Definitions
The critical exponents and are defined in terms of the behaviour of the order parameters and response functions near the critical point as follows
where
measures the temperature relative to the critical point.
Derivation
For the magnetic analogue of the Maxwell relations for the response functions, the relation
follows, and with thermodynamic stability requiring that , one has
which, under the conditions and the definition of the critical exponents gives
which gives the Rushbrooke inequality
Remarkably, in experiment and in exactly solved models, the inequality actually holds as an equality.
Critical phenomena
Statistical mechanics |
https://en.wikipedia.org/wiki/John%20K.%20Kruschke | John Kendall Kruschke is an American psychologist and statistician known for his work in connectionist models of human learning,
and in Bayesian statistical analysis.
He is Provost Professor Emeritus
in the Department of Psychological and Brain Sciences at Indiana University Bloomington.
He won the Troland Research Award from the National Academy of Sciences in 2002.
Research
Bayesian statistical analysis
Dissemination
Kruschke's popular textbook, Doing Bayesian Data Analysis,
was notable for its accessibility and unique scaffolding of concepts. The first half of the book used the simplest type of data (i.e., dichotomous values) for presenting all the fundamental concepts of Bayesian analysis, including generalized Bayesian power analysis and sample-size planning. The second half of the book used the generalized linear model as a framework for explaining applications to a spectrum of other types of data.
Kruschke has written many tutorial articles about Bayesian data analysis, including an open-access article that explains Bayesian and frequentist concepts side-by-side.
There is an accompanying online app that interactively does frequentist and Bayesian analyses simultaneously.
Kruschke gave a video-recorded plenary talk on this topic at the United States Conference on Teaching Statistics (USCOTS).
Bayesian analysis reporting guidelines
Bayesian data analyses are increasing in popularity but are still relatively novel in many fields, and guidelines for reporting Bayesian analyses are useful for researchers, reviewers, and students. Kruschke's open-access Bayesian analysis reporting guidelines (BARG)
provide a step-by-step list with explanation. For instance, the BARG recommend that if the analyst uses Bayesian hypothesis testing, then the report should include not only the Bayes factor but also the minimum prior model probability for the posterior model probability to exceed a decision criterion.
Assessing null values of parameters
Kruschke propos |
https://en.wikipedia.org/wiki/Keating%20model | In physics, The Keating Model is a model that theoretical physicist Patrick N. Keating introduced in 1966 to describe forces induced on neighboring atoms when one atom moves in a solid.
The term most often applies to the forces on first- and second-nearest neighboring atoms that arise when an atom is moved in tetrahedrally-bonded solids, such as diamond, silicon, germanium, and a number of other covalent crystals with the diamond or zinc blende structures.
Crystalline solids generally consist of an ordered array of interconnected atoms, generated by repetition of a unit cell in three dimensions, and are of two extreme types—ionic crystals, and covalent crystals. Others are intermediate: partly ionic and partly covalent. Ionic crystals are made up of quite different ions, such as Na+ and Cl− in common salt, for example, while covalent crystals such as diamond are made up of atoms that share electrons in a covalent bond.
In either case, attractive and repulsive forces resist moving an atom/ion or a set of them from their equilibrium positions, thus giving solids their rigidity against compressive, tensile, and shear stresses. The nature and strength of these forces is important for the scientific understanding of solids since they determine the way the solid responds to these stresses (elastic constants), the velocity of sound waves in it, its infra-red absorption, and many other properties.
Description
The Keating model is the result of a general method proposed to ensure that the elastic strain energy satisfies the requirement that it is invariant under a simple rotation of the crystal, without deformation. It is a formalism for the way adjacent and close-by atoms respond when one or more atoms move in covalently bonded crystals. It is also a specific parameterization of this response for diamond, silicon, and germanium. (see the article listed under "Further Reading").
The general method is applicable for small atomic displacements to all crystal structures. |
https://en.wikipedia.org/wiki/Strategic%20pluralism | Strategic pluralism (also known as the dual-mating strategy) is a theory in evolutionary psychology regarding human mating strategies that suggests women have evolved to evaluate men in two categories: whether they are reliable long term providers, and whether they contain high quality genes. The theory of strategic pluralism was proposed by Steven Gangestad and Jeffry Simpson, two professors of psychology at the University of New Mexico and Texas A&M University, respectively.
Experiments and studies
Although strategic pluralism is believed to occur for both animals and humans, the majority of experiments have been performed with humans. One experiment concluded that between short term and long-term relationships, males and females prioritized different things. It was shown that both preferred physical attractiveness for short term mates. However, for long term, females preferred males with traits that indicated that they could be better caretakers, whereas the males did not change their priorities.
The experimenters determined using the following setup: subjects were given an overall 'budget' and asked to assign points to different traits. For long-term mates, women gave more points to social and kindness traits, agreeing with results found in other studies suggesting that females prefer long term mates who would provide resources and emotional security for them as opposed to physically attractive mates. The females also prefer males who can offer them more financial security as this would help them raise their offspring.
Females have also chosen males who have more feminine appearances because of a (hypothesized) inverse relationship between a male's facial attractiveness and effort willing to spend in raising offspring. That is, more attractive males often put in less work as a caretaker while less attractive males will put in more work. On average, there is a wider amount of variability in male characteristics than in females. This suggests there are enough |
https://en.wikipedia.org/wiki/Eclipse%20Che | Eclipse Che is an open-source, Java-based developer workspace server and Online IDE (integrated development environment). It includes a multi-user remote development platform. The workspace server comes with a flexible RESTful webservice. It also contains a SDK for creating plug-ins for languages, frameworks or tools. Eclipse Che is an Eclipse Cloud Development (ECD) top-level project, allowing contributions from the user community.
History
Eclipse Che was first announced in October 2014. One of its main contributors, Codenvy, delivered the technological stack which Che is based on. The idea behind the cloud based IDE and its development came up in early 2009 by the eXo Platform. After three years of ongoing development the project raised $9 million and developed a stand-alone business called Codenvy. After announcing the Che project including intellectual property donation and participation in the Eclipse Cloud Development project the development of the Che project began. Codenvy itself is today a commercial product built on top of Eclipse Che. Today, there are many contributors besides Codenvy like IBM, Red Hat, Samsung, SAP, Microsoft, Intuit, eXo Platform, WSO2, and Serli, as well as numerous open source contributors from Brazil, Canada, China, France, India, Russia, Sri Lanka, Ukraine, and United States.
Licensing
Eclipse Che is released under the Eclipse Public License which is similar to the Common Public License.
Name
The name "Che" is based on the fact that most of the development is done in Cherkasy (Ukraine).
Supported languages and frameworks
By default, the following programming languages and frameworks are supported:
Approach
Che itself is a workspace server running on an application server. Che provides an integrated IDE which can be used via a browser. After the initial load the IDE provides a dynamic user interface including known components like wizards, editors, toolbars and many more. The user has the opportunity to create workspaces, proje |
https://en.wikipedia.org/wiki/Donsker%27s%20theorem | In probability theory, Donsker's theorem (also known as Donsker's invariance principle, or the functional central limit theorem), named after Monroe D. Donsker, is a functional extension of the central limit theorem.
Let be a sequence of independent and identically distributed (i.i.d.) random variables with mean 0 and variance 1. Let . The stochastic process is known as a random walk. Define the diffusively rescaled random walk (partial-sum process) by
The central limit theorem asserts that converges in distribution to a standard Gaussian random variable as . Donsker's invariance principle extends this convergence to the whole function . More precisely, in its modern form, Donsker's invariance principle states that: As random variables taking values in the Skorokhod space , the random function converges in distribution to a standard Brownian motion as
Formal statement
Let Fn be the empirical distribution function of the sequence of i.i.d. random variables with distribution function F. Define the centered and scaled version of Fn by
indexed by x ∈ R. By the classical central limit theorem, for fixed x, the random variable Gn(x) converges in distribution to a Gaussian (normal) random variable G(x) with zero mean and variance F(x)(1 − F(x)) as the sample size n grows.
Theorem (Donsker, Skorokhod, Kolmogorov) The sequence of Gn(x), as random elements of the Skorokhod space , converges in distribution to a Gaussian process G with zero mean and covariance given by
The process G(x) can be written as B(F(x)) where B is a standard Brownian bridge on the unit interval.
History and related results
Kolmogorov (1933) showed that when F is continuous, the supremum and supremum of absolute value, converges in distribution to the laws of the same functionals of the Brownian bridge B(t), see the Kolmogorov–Smirnov test. In 1949 Doob asked whether the convergence in distribution held for more general functionals, thus formulating a problem of weak converg |
https://en.wikipedia.org/wiki/Plant%20memory | In plant biology, plant memory describes the ability of a plant to retain information from experienced stimuli and respond at a later time. For example, some plants have been observed to raise their leaves synchronously with the rising of the sun. Other plants produce new leaves in the spring after overwintering. Many experiments have been conducted into a plant's capacity for memory, including sensory, short-term, and long-term. The most basic learning and memory functions in animals have been observed in some plant species, and it has been proposed that the development of these basic memory mechanisms may have developed in an early organismal ancestor.
Some plant species appear to have developed conserved ways to use functioning memory, and some species may have developed unique ways to use memory function depending on their environment and life history.
The use of the term plant memory still sparks controversy. Some researchers believe the function of memory only applies to organisms with a brain and others believe that comparing plant functions resembling memory to humans and other higher division organisms may be too direct of a comparison. Others argue that the function of the two are essentially the same and this comparison can serve as the basis for further understanding into how memory in plants works.
History
Experiments involving the curling of pea tendrils were some of the first to explore the concept of plant memory. Mark Jaffe recognized that pea plants coil around objects that act as support to help them grow. Jaffe’s experiments included testing different stimuli to induce coiling behavior. One such stimulus was the effect of light on the coiling mechanism. When Jaffe rubbed the tendrils in light, he witnessed the expected coiling response. When subjected to perturbation in darkness, the pea plants did not exhibit coiling behavior. Tendrils from the dark experiment were brought back into light hours later, exhibiting a coiling response without a |
https://en.wikipedia.org/wiki/Rhodopirellula%20caenicola | Rhodopirellula caenicola is a Gram-negative, strictly aerobic and non-motile bacterium from the genus of Rhodopirellula which has been isolated from isolated from iron sand. |
https://en.wikipedia.org/wiki/Geographical%20distance | Geographical distance or geodetic distance is the distance measured along the surface of the Earth. The formulae in this article calculate distances between points which are defined by geographical coordinates in terms of latitude and longitude. This distance is an element in solving the second (inverse) geodetic problem.
Introduction
Calculating the distance between geographical coordinates is based on some level of abstraction; it does not provide an exact distance, which is unattainable if one attempted to account for every irregularity in the surface of the Earth. Common abstractions for the surface between two geographic points are:
Flat surface;
Spherical surface;
Ellipsoidal surface.
All abstractions above ignore changes in elevation. Calculation of distances which account for changes in elevation relative to the idealized surface are not discussed in this article.
Nomenclature
Distance, is calculated between two points, and . The geographical coordinates of the two points, as (latitude, longitude) pairs, are and respectively. Which of the two points is designated as is not important for the calculation of distance.
Latitude and longitude coordinates on maps are usually expressed in degrees. In the given forms of the formulae below, one or more values must be expressed in the specified units to obtain the correct result. Where geographic coordinates are used as the argument of a trigonometric function, the values may be expressed in any angular units compatible with the method used to determine the value of the trigonometric function. Many electronic calculators allow calculations of trigonometric functions in either degrees or radians. The calculator mode must be compatible with the units used for geometric coordinates.
Differences in latitude and longitude are labeled and calculated as follows:
It is not important whether the result is positive or negative when used in the formulae below.
"Mean latitude" is labeled and calculated as follows:
|
https://en.wikipedia.org/wiki/Congenital%20rubella%20syndrome | Congenital rubella syndrome (CRS) occurs when an unborn baby is infected with the rubella virus (German measles) via maternal-fetal transmission and develops birth defects. The most common congenital defects affect the ophthalmologic, cardiac, auditory, and neurologic systems.
Rubella infection in pregnancy can result in various outcomes ranging from asymptomatic infection to congenital defects to miscarriage and fetal death. If infection occurs 0–11 weeks after conception, the infant has a 90% risk of being affected. If the infection occurs 12–20 weeks after conception, the risk is 20%. Infants are not generally affected if rubella is contracted during the third trimester. Diagnosis of congenital rubella syndrome is made through a series of clinical and laboratory findings and management is based on the infant’s clinical presentation. Maintaining rubella outbreak control via vaccination is essential in preventing congenital rubella infection and congenital rubella syndrome.
Congenital rubella syndrome was discovered in 1941 by Australian Norman McAlister Gregg.
Signs and symptoms
The classic triad for congenital rubella syndrome is:
Sensorineural deafness (58% of patients)
Eye abnormalities—especially retinopathy, cataract, glaucoma, and microphthalmia (43% of patients)
Congenital heart disease—especially pulmonary artery stenosis and patent ductus arteriosus (50% of patients)
Other manifestations of CRS may include:
Spleen, liver, or bone marrow problems (some of which may disappear shortly after birth)
Intellectual disability
Small head size (microcephaly)
Low birth weight
Thrombocytopenic purpura, leading to easy or excessive bleeding or bruising
Extramedullary hematopoiesis (presents as a characteristic blueberry muffin rash)
Enlarged liver (hepatomegaly)
Small jaw size (micrognathia)
Skin lesions
Children who have been exposed to rubella in the womb should also be watched closely as they age for any indication of:
Developmental delay
Au |
https://en.wikipedia.org/wiki/Biomedical%20tissue | Biomedical tissue is biological tissue used for organ transplantation and medical research, particularly cancer research. When it is used for research it is a biological specimen.
Such tissues and organs may be referred to as implant tissue, allograft, xenograft, skin graft tissue, human transplant tissue, or implant bone. Tissue is stored in tissue establishments or tissue banks under cryogenic conditions. Fluids such as blood, blood products and urine are stored in fluid banks under similar conditions.
Regulation
The collection, storage, analysis and transplantation of human tissue involves significant ethical and safety issues, and is heavily regulated. Each country sets its own framework for ensuring the safety of human tissue products.
The regulation of human transplantation in the United Kingdom is set out in the Human Tissue Act 2004 and managed by the Human Tissue Authority.
Tissue banks in the US are monitored by the Food and Drug Administration (FDA). The Code of Federal Regulations sets out the following topics:
Donor Screening and Testing: the determination of donor suitability for human tissue intended for transplantation.
Procedures and Records: the written procedures and records that must be kept
Inspection of Tissue Establishments: the importation of tissues from abroad and the retention, recall, and destruction of human tissue.
Notable regulation cases
Biomedical Tissue Services, Inc. is at the heart of an investigation by the Food and Drug Administration. FDA Provides Information on Investigation into Human Tissue for Transplantation
See also
Biomaterial
Implant (medicine)
Biomesh
Footnotes
External links
The UK Human Tissue Act 2004
Specimen Central biorepository list A worldwide listing of active biobanks and biorepositories
Tissues (biology)
Transplantation medicine
Medical ethics |
https://en.wikipedia.org/wiki/Stroke%20volume | In cardiovascular physiology, stroke volume (SV) is the volume of blood pumped from the left ventricle per beat. Stroke volume is calculated using measurements of ventricle volumes from an echocardiogram and subtracting the volume of the blood in the ventricle at the end of a beat (called end-systolic volume) from the volume of blood just prior to the beat (called end-diastolic volume). The term stroke volume can apply to each of the two ventricles of the heart, although it usually refers to the left ventricle. The stroke volumes for each ventricle are generally equal, both being approximately 70 mL in a healthy 70-kg man.
Stroke volume is an important determinant of cardiac output, which is the product of stroke volume and heart rate, and is also used to calculate ejection fraction, which is stroke volume divided by end-diastolic volume. Because stroke volume decreases in certain conditions and disease states, stroke volume itself correlates with cardiac function.
Calculation
Its value is obtained by subtracting end-systolic volume (ESV) from end-diastolic volume (EDV) for a given ventricle.
In a healthy 70-kg man, ESV is approximately 50 mL and EDV is approximately 120mL, giving a difference of 70 mL for the stroke volume.
Stroke work refers to the work, or pressure of the blood ("P") multiplied by the stroke volume.
ESV and EDV are fixed variables. Heart rate and Stroke volume are unfixed.
Determinants
Men, on average, have higher stroke volumes than women due to the larger size of their hearts. However, stroke volume depends on several factors such as heart size, contractility, duration of contraction, preload (end-diastolic volume), and afterload. Corresponding to the oxygen uptake, women's need for blood flow does not decrease and a higher cardiac frequency makes up for their smaller stroke volume.
Exercise
Prolonged aerobic exercise training may also increase stroke volume, which frequently results in a lower (resting) heart rate. Reduced heart rat |
https://en.wikipedia.org/wiki/Neurocutaneous%20melanosis | Neurocutaneous melanosis is a congenital disorder characterized by the presence of congenital melanocytic nevi on the skin and melanocytic tumors in the leptomeninges of the central nervous system. These lesions may occur in the amygdala, cerebellum, cerebrum, pons and spinal cord of patients. Although typically asymptomatic, malignancy occurs in the form of leptomeningeal melanoma in over half of patients. Regardless of the presence of malignancy, patients with symptomatic neurocutaneous melanosis generally have a poor prognosis with few treatment options. The pathogenesis of neurocutaneous melanosis is believed to be related to the abnormal postzygotic development of melanoblasts and mutations of the NRAS gene.
Signs and symptoms
Neurocutaneous melanosis is associated with the presence of either giant congenital melanocytic nevi or non-giant nevi of the skin. It is estimated that neurocutaneous melanosis is present in 2% to 45% of patients with giant congenital melanocytic nevi. Patients with non-giant congenital melanocytic nevi seem to have a much lower, but undefined risk. Of these patients, only a small number are symptomatic, usually displaying symptoms before the age of 2. These symptoms are the result of melanocytic lesions being present in the leptomeninges of the central nervous system. Symptoms can include:
Papilledema
Cranial palsies
Headache
Vomiting
Seizures
Others symptoms may also exist that are related to an increase in intracranial pressure. These symptoms seem to be present regardless of the malignancy of the melanin deposits within the central nervous system.
Approximately 10% of patient with neurocutaneous melanosis also present the Dandy–Walker syndrome and associated Dandy-Walker malformation. This malformation involves an enlargement of the posterior fossae and fourth ventricle along with agenesis of the cerebellar vermis. The abnormalities of the leptomeninges during fetal development due to neurocutaneous melanosis may be the cau |
https://en.wikipedia.org/wiki/Lubuntu | Lubuntu ( ) is a lightweight Linux distribution based on Ubuntu and uses the LXQt desktop environment in place of Ubuntu's GNOME desktop. Lubuntu was originally touted as being "lighter, less resource hungry and more energy-efficient", but now aims to be "a functional yet modular distribution focused on getting out of the way and letting users use their computer".
Lubuntu originally used the LXDE desktop, but moved to the LXQt desktop with the release of Lubuntu 18.10 in October 2018, due to the slow development of LXDE, losing support for GTK 2 as well as the more active and stable LXQt development without GNOME dependencies.
The name Lubuntu is a portmanteau of LXQt and Ubuntu. The LXQt name derives from the merger of the LXDE and Razor-qt projects, while the word Ubuntu means "humanity towards others" in the Zulu and Xhosa languages.
Lubuntu received official recognition as a formal member of the Ubuntu family on 11 May 2011, commencing with Lubuntu 11.10, which was released on 13 October 2011.
History
The LXDE desktop was first made available for Ubuntu in October 2008, with the release of Ubuntu 8.10 Intrepid Ibex. These early versions of Lubuntu, including 8.10, 9.04 and 9.10, were not available as separate ISO image downloads, and could only be installed on Ubuntu as separate lubuntu-desktop packages from the Ubuntu repositories. LXDE can also be retroactively installed in earlier Ubuntu versions.
In February 2009, Mark Shuttleworth invited the LXDE project to become a self-maintained project within the Ubuntu community, with the aim of leading to a dedicated new official Ubuntu derivative to be called Lubuntu.
In March 2009, the Lubuntu project was started on Launchpad by Mario Behling, including an early project logo. The project also established an official Ubuntu wiki project page, that includes listings of applications, packages, and components.
In August 2009, the first test ISO was released as a Live CD, with no installation option.
Initial te |
https://en.wikipedia.org/wiki/Racal%20suit | A Racal suit (also known as a Racal space suit) is a protective suit with a powered air-purifying respirator (PAPR). It consists of a plastic suit and a battery-operated blower with HEPA filters that supplies filtered air to a positive-pressure hood (also known as a Racal hood). Racal suits were among the protective suits used by the Aeromedical Isolation Team (AIT) of the United States Army Medical Research Institute of Infectious Diseases to evacuate patients with highly infectious diseases for treatment.
Originally, the hood was manufactured by Racal Health & Safety, a subsidiary of Racal Electronics located in Frederick, Maryland, the same city where AIT was based. The division of Racal responsible for the suit's manufacture later became part of 3M, and the respirator product line was branded as 3M/Racal.
Components
The main body of the protective suit consists of a lightweight coverall made of polyvinyl chloride (PVC), rubber gloves, and rubber boots. Originally, the coverall was in a bright orange color, and the Racal suit was known as an orange suit.
The hood is a separate component from the protective suit. The Racal hood is a type of PAPR consisting of a transparent hood connected to a respirator, which is powered by a rechargeable battery. The respirator has three HEPA filters that are certified to remove 99.7% of particles of 0.03 to 3.0 microns in diameter. The filtered air is supplied at the rate of 170 L/min to the top of the hood under positive pressure for breathing and cooling. The air is forced out through an air exhaust valve at the base of the hood. A two-way radio system is installed inside the hood for communication. The AIT later switched from using transparent bubble hoods to butyl rubber hoods.
Procedures
The main purpose of the AIT was to evacuate a patient from the field to a specialized isolation unit. As part of their procedures, AIT members wore Racal suits while transporting the patients. They were trained to take a bathroom break |
https://en.wikipedia.org/wiki/Veterinary%20ethics | Veterinary ethics is a system of moral principles that apply values and judgements to the practice of veterinary medicine. As a scholarly discipline, veterinary ethics encompasses its practical application in clinical settings as well as work on its history, philosophy, theology, and sociology. Veterinary ethics combines veterinary professional ethics and the subject of animal ethics. The subject of veterinary ethics can be interpreted as an extension of critical thinking skills necessary to make the decisions in veterinary care in order to support the profession's responsibilities to animal kind and mankind.
History
Animal welfare as a subject has been studied in great depth. It largely looks at the ways in which an animal may suffer in particular circumstances, or how their lives may be enriched. Animal ethics is another well-documented subject, and philosophers since Aristotle, have commented on its importance. Often referred to as “the animal problem,’ the questions that seem to be asked in this field are at their foundation trying to determine what the morally relevant difference is between animals and humans, and if there is no difference how do we justify treating animals a certain way, and if there is a difference then what is it about this difference that allows us to treat animals in a certain way.
Veterinary ethics is a modern subject that does not have a defined start point. As it combines the study of animal welfare and animal ethics as its root and uses information from this as data for its deliberations it could be said to have a long history, however as an academic discipline it is only recently that works have been published on the topic.
The two academics who have written on veterinary ethics for the longest time are Bernard Rollin (Colorado State University) and Jerrold Tannenbaum (University of California, Davis). More recently, emergency veterinarian Jessica Fragola wrote in 2022 about the ethics of animal triage, with pressures on ve |
https://en.wikipedia.org/wiki/Theory%20of%20solar%20cells | The theory of solar cells explains the process by which light energy in photons is converted into electric current when the photons strike a suitable semiconductor device. The theoretical studies are of practical use because they predict the fundamental limits of a solar cell, and give guidance on the phenomena that contribute to losses and solar cell efficiency.
Working explanation
Photons in sunlight hit the solar panel and are absorbed by semi-conducting materials.
Electrons (negatively charged) are knocked loose from their atoms as they are excited. Due to their special structure and the materials in solar cells, the electrons are only allowed to move in a single direction. The electronic structure of the materials is very important for the process to work, and often silicon incorporating small amounts of boron or phosphorus is used in different layers.
An array of solar cells converts solar energy into a usable amount of direct current (DC) electricity.
Photogeneration of charge carriers
When a photon hits a piece of semiconductor, one of three things can happen:
The photon can pass straight through the semiconductor — this (generally) happens for lower energy photons.
The photon can reflect off the surface.
The photon can be absorbed by the semiconductor if the photon energy is higher than the band gap value. This generates an electron-hole pair and sometimes heat depending on the band structure.
When a photon is absorbed, its energy is given to an electron in the crystal lattice. Usually this electron is in the valence band. The energy given to the electron by the photon "excites" it into the conduction band where it is free to move around within the semiconductor. The network of covalent bonds that the electron was previously a part of now has one fewer electron. This is known as a hole, and it has positive charge. The presence of a missing covalent bond allows the bonded electrons of neighboring atoms to move into the "hole", leaving another hole b |
https://en.wikipedia.org/wiki/Nailing%20the%20colours | Nailing the colours (also nailing the colours to the mast or nailing the flag) is a practice dating back to the Age of Sail that expresses a defiant refusal to surrender, and willingness to fight to the last man.
During the Age of Sail, ships would legally fight only while flying their national flag. Flying another flag was considered to be a legitimate ruse de guerre only until the beginning of the fight. Striking the colours was a sign of surrender. Indeed, when shot or shrapnel felled a ship's flag (such as by severing the halyard that held it up), her opponent would cease firing and inquire whether she was capitulating.
In contrast, fixing the battle ensign with nails would prevent it from being removed easily, and effectively prevented the surrender. It became an expression of defiance and willingness to force oneself to fight up to the bitter end.
The practice became a powerful and recurrent propaganda tool during the French Revolutionary Wars. It actually happened on the Tonnant at the Battle of the Nile and on the San Juan Nepomuceno at the Battle of Trafalgar. It was also wrongly claimed that the Vengeur du Peuple had done so during the Glorious First of June, when she had in fact struck. In the Royal Navy, Jack Crawford became famous for the deed.
See also
Striking the colours
With flying colours
Battle of Mobile Bay, section "Farragut lashed to the rigging" |
https://en.wikipedia.org/wiki/Ferromagnetic%20resonance | Ferromagnetic resonance, or FMR, is coupling between an electromagnetic wave and the magnetization of a medium through which it passes. This coupling induces a significant loss of power of the wave. The power is absorbed by the precessing magnetization (Larmor precession) of the material and lost as heat. For this coupling to occur, the frequency of the incident wave must be equal to the precession frequency of the magnetization (Larmor frequency) and the polarization of the wave must match the orientation of the magnetization.
This effect can be used for various applications such as spectroscopic techniques or conception of microwave devices.
The FMR spectroscopic technique is used to probe the magnetization of ferromagnetic materials. It is a standard tool for probing spin waves and spin dynamics. FMR is very broadly similar to electron paramagnetic resonance (EPR), and also somewhat similar to nuclear magnetic resonance (NMR), except that FMR probes the sample magnetization resulting from the magnetic moments of dipolar-coupled but unpaired electrons, while NMR probes the magnetic moment of atomic nuclei that are screened by the atomic or molecular orbitals surrounding such nuclei of non-zero nuclear spin.
The FMR resonance is also the basis of various high-frequency electronic devices, such as resonance isolators or circulators.
History
Ferromagnetic resonance was experimentally discovered by V. K. Arkad'yev when he observed the absorption of UHF radiation by ferromagnetic materials in 1911. A qualitative explanation of FMR along with an explanation of the results from Arkad'yev was offered up by Ya. G. Dorfman in 1923, when he suggested that the optical transitions due to Zeeman splitting could provide a way to study ferromagnetic structure.
A 1935 paper published by Lev Landau and Evgeny Lifshitz predicted the existence of ferromagnetic resonance of the Larmor precession, which was independently verified in experiments by J. H. E. Griffiths (UK) and E |
https://en.wikipedia.org/wiki/Ballochmyle%20cup%20and%20ring%20marks | The Ballochmyle cup and ring marks were first recorded at Ballochmyle (NS 5107 2552), Mauchline, East Ayrshire, Scotland in 1986, very unusually carved on a vertical red sandstone cliff face, forming one of the most extensive areas of such carvings as yet found in Britain. They have been designated a scheduled monument.
Discovery
These carvings or petroglyphs were first recorded in 1986 (although a '1751' carved date suggests an earlier discovery) when the Kingencleugh Estate decided to clear an area of vegetation along the north side of the Liddell Burn that is a minor tributary stream of the River Ayr in an area famous for its quarrying of red sandstone. The removal of vegetation exposed the carvings that are distributed across two faces of a vertical outcrop of rock and they were reported to the Dick Institute in Kilmarnock. The presence of possible medieval carvings, the extensive quarrying with numerous workmen employed in the area, especially during the construction of the Ballochmyle Viaduct, emphasises how surprising it is that these glyphs were overlooked for so long, especially as they are only about 2 km south-east of Mauchline's town centre.
Description
The rock here is described as being a "pink dessert sandstone from the Permian age showing clear signs of dune bedding". The cup and ring marks are composed of two 'panels' with several hundred 'cup and ring' and other glyphs or carvings in a range of styles, ranging from single shallow cups through to deeper cups with multiple rings. Less common, but unique in the Scottish context are ‘square with cup’ carvings; ‘ringed stars’ are also present. Three deer-like carvings and some other inscriptions with Lombardic style letters were also carved into the rockface and these are thought to be medieval in date.
Several feet of soil were removed from the bottom of the corner that divides the two main halves of the site and this uncovered three 'trilithon-like' carvings and others may await discovery where the |
https://en.wikipedia.org/wiki/Intervention%20%28convention%29 | Intervention was a yearly Internet culture convention held in Rockville, Maryland. Intervention (a combination of the words "Internet" and "Convention") highlighted independent artists from all spectrums of creative output who use the Internet as their primary distribution method. The convention hosted panels, workshops, movie showings, music concerts, open gaming, and dance events. Later events added a children's track and live musical performances. Following the 2016 event, organizers placed the convention on hiatus and said a plan would be developed for its return, but this was made impossible following the abrupt failure and bankruptcy of its parent corporation, Onezumi Events.
Locations and dates |
https://en.wikipedia.org/wiki/List%20of%20MeSH%20codes%20%28D12.776.124%29 | The following is a partial list of the "D" codes for Medical Subject Headings (MeSH), as defined by the United States National Library of Medicine (NLM).
This list covers blood proteins. For other protein-related codes, see List of MeSH codes (D12.776).
Codes before these are found at List of MeSH codes (D12.776.097). Codes following these are found at List of MeSH codes (D12.776.157). For other MeSH codes, see List of MeSH codes.
The source for this content is the set of 2006 MeSH Trees from the NLM.
– blood proteins
– acute-phase proteins
– alpha 1-antichymotrypsin
– alpha 1-antitrypsin
– alpha-macroglobulins
– c-reactive protein
– ceruloplasmin
– complement c3
– fibrinogen
– fibrinogens, abnormal
– haptoglobins
– hemopexin
– orosomucoid
– serum albumin
– serum amyloid a protein
– serum amyloid p-component
– transferrin
– trypsin inhibitor, kazal pancreatic
– ankyrins
– anion exchange protein 1, erythrocyte
– blood coagulation factors
– beta-thromboglobulin
– factor v
– factor va
– factor vii
– factor viia
– factor viii
– factor viiia
– factor ix
– factor ixa
– factor x
– factor xa
– factor xi
– factor xia
– factor xii
– factor xiia
– factor xiii
– factor xiiia
– fibrinogen
– fibrinogens, abnormal
– fibrinopeptide a
– fibrinopeptide b
– kallikreins
– prekallikrein
– kininogens
– kininogen, high-molecular-weight
– kininogen, low-molecular-weight
– plasminogen activator inhibitor 1
– plasminogen activator inhibitor 2
– plasminogen activators
– streptokinase
– anistreplase
– streptodornase and streptokinase
– tissue plasminogen activator
– urinary plasminogen activator
– platelet factor 3
– platelet factor 4
– prothrombin
– thrombin
– thromboplastin
– von willebrand factor
– fibrin
– fibrin fibrinogen degradation products
– fibrin foam
– fibrin tissue adhesive
– fibrinopeptide a
– fibrinopeptide b
– glycophorin
– hemocyanin
– hemoglobins
– carboxyhemoglobin
– erythrocruorins
– fetal hemoglobi |
https://en.wikipedia.org/wiki/Sangaku | Sangaku or san gaku () are Japanese geometrical problems or theorems on wooden tablets which were placed as offerings at Shinto shrines or Buddhist temples during the Edo period by members of all social classes.
History
The sangaku were painted in color on wooden tablets (ema) and hung in the precincts of Buddhist temples and Shinto shrines as offerings to the kami and buddhas, as challenges to the congregants, or as displays of the solutions to questions. Many of these tablets were lost during the period of modernization that followed the Edo period, but around nine hundred are known to remain.
Fujita Kagen (1765–1821), a Japanese mathematician of prominence, published the first collection of sangaku problems, his Shimpeki Sampo (Mathematical problems Suspended from the Temple) in 1790, and in 1806 a sequel, the Zoku Shimpeki Sampo.
During this period Japan applied strict regulations to commerce and foreign relations for western countries so the tablets were created using Japanese mathematics, developed in parallel to western mathematics. For example, the connection between an integral and its derivative (the fundamental theorem of calculus) was unknown, so sangaku problems on areas and volumes were solved by expansions in infinite series and term-by-term calculation.
Select examples
A typical problem, which is presented on an 1824 tablet in Gunma Prefecture, covers the relationship of three touching circles with a common tangent, a special case of Descartes' theorem. Given the size of the two outer large circles, what is the size of the small circle between them? The answer is:
(See also Ford circle.)
Soddy's hexlet, thought previously to have been discovered in the west in 1937, had been discovered on a sangaku dating from 1822.
One sangaku problem from Sawa Masayoshi and other from Jihei Morikawa were solved only recently.
See also
Equal incircles theorem
Japanese theorem for concyclic polygons
Japanese theorem for concyclic quadrilaterals
Probl |
https://en.wikipedia.org/wiki/The%20Clean%20Network | The Clean Network was a U.S. government-led, bi-partisan effort announced by then U.S. Secretary of State Mike Pompeo in August 2020 to address what it describes as "the long-term threat to data privacy, security, human rights and principled collaboration posed to the free world from authoritarian malign actors." Its promoters state that it has resulted in an "alliance of democracies and companies," "based on democratic values." According to the Trump administration, the Clean Network is intended to implement internationally accepted digital trust standards across a coalition of trusted partners.
In December 2020, the United States announced that more than 60 nations, representing more than two thirds of the world's gross domestic product, and 200 telecom companies, have publicly committed to the principles of The Clean Network. This alliance of democracies includes 27 of the 30 NATO members; 26 of the 27 EU members, 31 of the 37 OECD nations, 11 of the 12 Three Seas nations as well as Japan, Israel, Australia, South Korea, Singapore, Taiwan, Canada, New Zealand, Vietnam and India.
The term "Clean Network" was coined by U.S. Undersecretary of State Keith Krach, who initially led the initiative, which includes officials in the Treasury Department, the Office of the U.S. Trade Representative, the National Security Council, and the Commerce Department. According to Bloomberg, Krach is credited with coordinating a variety of national and regional approaches to shape a more unified international project, relying on trust more than compulsion—a notable change in tone after years in which the Trump administration pursued a go-it-alone, "America First" strategy. On April 22, 2021, David Ignatius of the Washington Post stated that Krach's Clean Network provides continuity with the Biden administration's desire to get democracies together on the same playing field on technology.
Krach described the Huawei effort as a “beachhead” in a wider battle to unite against Chinese e |
https://en.wikipedia.org/wiki/The%20Game%20of%20Logic | The Game of Logic is a book, published in 1886, written by the English mathematician Charles Lutwidge Dodgson (1832–1898), better known under his literary pseudonym Lewis Carroll.
In addition to his well-known children's literature, Dodgson/Carroll was an academic mathematician who worked in mathematical logic. The book describes, in an informal and playful style, the use of a board game to represent logical propositions and inferences. Dodgson/Carroll incorporated the game into a longer and more formal introductory logic textbook titled Symbolic Logic, published in 1897. The books are sometimes reprinted in a single volume.
The book aims to teach players the fundamentals of logic by asking players to use coins on a board. The proposition used in this context is: "Some fresh cakes are sweet." The game world is divided into four quadrants. It is to be played with five gray coins and four red coins. A red coin symbolizes one or more cakes being present in an area while a gray coin symbolizes the absence of the cake(s). Each quadrant represents a variation of the original proposition. The cakes are fresh and sweet within the northwest quadrant. They are fresh but not sweet in the northeast. They are neither fresh nor sweet in the southeast. They are not fresh but are sweet in the southwest.
The four quadrants are further divided into two subclasses: cakes that are eatable and those that are non-eatable. This subdivision allows players to understand more complex propositions and syllogisms.
The second half of the book introduces players to a 2x2x2 diagram. This allows for players to solve problems involving three propositions at the same time.
The book is divided into several chapters. The first portion, "To My Childhood-Friend" is as an introduction from the author to his readers. This is followed by a preface chapter. Chapter 1 is divided into three parts. In the first part, the author describes the three different types o |
https://en.wikipedia.org/wiki/Rudder%20%28software%29 | Rudder is an open source audit and configuration management utility to help automate system configuration across large IT infrastructures. Rudder relies on a lightweight local agent installed on each managed machine.
Rudder is produced by Normation, founded in 2010. Its server-side web interface is written in Scala and its local agent is written in C, and are published as free software under the GNU General Public License 3.0.
Features
Host inventory
Feature-complete Web interface
Standardized, reusable policies
Custom Policy editor
Central reporting and historic information for policy applied to hosts
Grouping based on search queries run against inventory
Automatic updating of such groups (dynamic groups)
Dynamic generation of per-host policies (lessens risk of data leaks from shared policy)
Change Request / Validation
REST API
Git backend
History
Rudder was created by the founding team of Normation and first released as free software in October 2011.
Rudder 3.0 was released in February 2015.
Platform support
The following operating systems are supported as a Root server:
Debian Linux 9 and 10
Ubuntu 16.04 LTS, 18.04 LTS and 20.04 LTS
Red Hat Enterprise Linux (RHEL) / CentOS 7 and 8
SUSE Linux Enterprise Server (SLES) 12 et 15
The following operating systems are supported for Rudder Nodes and packages are available for these platforms:
Debian Linux 5 to 10
Ubuntu 10.04 LTS to 20.04 LTS
Red Hat Enterprise Linux (RHEL) / CentOS 3 to 8
SUSE Linux Enterprise Server (SLES) 10 to 15
IBM AIX 5 to 7
Slackware 14
Microsoft Windows Server 2008R2 or higher
See also
CFEngine
Ansible (software)
Bcfg2
Chef (software)
Puppet (software)
Salt (software)
Comparison of open source configuration management software
DevOps
Otter (software) |
https://en.wikipedia.org/wiki/International%20Federation%20on%20Ageing | The International Federation on Ageing (IFA; ) is an international non-governmental organization founded in 1973 and based in Toronto, Ontario, Canada working in the field of ageing, older persons and ageing-related issues such as ageism, The intent of the organisation is for NGOs, the corporate sector, academia, government, and individuals working together to make, according to the IFA’s mission statement, a "change for older people throughout the world by stimulating, collecting, analyzing, and disseminating information on rights, policies and practices that improve the quality of life of people as they age".
The IFA has General Consultative Status at the United Nations Economic and Social Council (ECOSOC).
History
At the beginning of the 70s, the United Nations started to become interested in the issue of ageing; and the need for an international organization promoting information exchange at an international level was identified. During the summer of 1972, at an initiative hosted by AARP, twenty representatives of thirteen nations met at the London School of Economics to discuss forming an organization one year later, in December 1973, they met again to formally approve a constitution and bylaws for an International Federation on Ageing.
In the early 80s, the IFA was one of the first organizations to call for a World Assembly on Ageing (WAA). An assembly was finally organized in 1982 and resulted in the world’s first International Plan of Action on Ageing. IFA’s General Secretary at the time, William Kerrigan, became the Secretary-General of the World Assembly. The IFA secretariat remained mostly at AARP headquarters (with brief stints in the UK and Australia) until the early 1990s when the support role of AARP formally ended, and the secretariat moved to Montreal, Quebec, Canada.
The organization obtained Consultative status with the Economic and Social Council (ECOSOC) of the United Nations in 1995, the World Health Organization (WHO), the International L |
https://en.wikipedia.org/wiki/Chromium%20cycle | The chromium cycle is the biogeochemical cycle of chromium through the atmosphere, hydrosphere, biosphere and lithosphere.
Biogeochemical cycle
Terrestrial weathering and river transport
Chromium has two common oxidation states relevant for environmental conditions: trivalent chromium, Cr(III) (reduced form), and hexavalent chromium, Cr(VI) (most oxidized form). The poorly soluble trivalent chromium cation () strongly adsorbs onto clay particles and particulate organic matter, whereas the highly toxic and carcinogenic hexavalent chromate anion () is soluble and non-sorbed, making it a toxic contaminant in environmental systems. Chromium commonly exists in soil and rocks as highly insoluble trivalent chromium, such as chromite (, or FeO·), a mixed oxide mineral of the spinel group resembling magnetite (, , or FeO·). Terrestrial weathering could cause trivalent chromium to be oxidized by manganese oxides to hexavalent chromium, which is then solubilized and cycled to the ocean through rivers. Estuaries release particulate chromium from rivers to the sea, increasing the dissolved fluxes of chromium to the ocean.
Oceanic cycling
Soluble hexavalent chromium is the most common type of chromium in oceans, where over 70% of dissolved chromium in the ocean is found in oxyanions such as chromate (). Soluble trivalent chromium is also found in the oceans where complexation with organic ligands occurs. Chromium is estimated to have a residence time of 6,300 years in the oceans. Hexavalent chromium is reduced to trivalent chromium in oxygen minimum zones or at the surface of the ocean by divalent iron and organic ligands. There are four sinks of chromium from the oceans: (1) oxic sediments in pelagic zones, (2) hypoxic sediments in continental margins, (3) anoxic or sulfidic sediments in basins or fjords with permanently anoxic or sulfidic (euxinic) bottom waters, and (4) marine carbonates.
Influence from other biogeochemical cycles
Manganese (III) can oxidize Cr(III) to |
https://en.wikipedia.org/wiki/Speedtest.net | Speedtest.net, also known as Speedtest by Ookla, is a web service that provides free analysis of Internet access performance metrics, such as connection data rate and latency. It is the flagship product of Ookla, a web testing and network diagnostics company founded in 2006, and based in Seattle, Washington, United States.
The service measures the data throughput (speed) and latency (connection delay) of an Internet connection against one of around 11,000 geographically dispersed servers (as of August 2021). Each test measures the data rate for the download direction, i.e. from the server to the user computer, and the upload data rate, i.e. from the user's computer to the server. The tests are performed within the user's web browser or within apps. , over 21 billion speed tests have been completed.
Tests were previously performed using the Hypertext Transfer Protocol (HTTP) at Layer 7 of the OSI model. To further improve accuracy, Speedtest.net now performs tests via direct Transmission Control Protocol (TCP) sockets and uses a custom protocol for communication between servers and clients.
The site also offers detailed statistics based on test results. This data has been used by numerous publications in the analysis of Internet access data rates around the world.
History
The owner and operator of Speedtest.net, Ookla, was established in 2006 by partners Mike Apgar and Doug Suttles. Suttles suggested the name Ookla because he already owned the Ookla.com domain name in honor of his pet cat, who was in turn named for a character on the TV series Thundarr the Barbarian. The domain speedtest.net has been used to host a speed test since 2000, however speedtest.net only became known to the general public after the acquisition by Ookla in 2006.
As of 2011, Ookla claimed 80% market share and was one of the top 1000 most popular websites. At the time, Ookla derived its revenue primarily from fees paid by companies to license custom speed test and proprietary testing so |
https://en.wikipedia.org/wiki/Candwich | Candwich is a canned food product created and produced by Mark One Foods, LLC (aka MK1 Foods). Candwich is marketed as "the only sandwich in a can." Its slogan is, "Quick & Tasty, Ready to Eat".
History
Founder and creator Mark Kirkland claims he came up with the idea for Candwich when he was drinking a can of soda with a cookie, and wondered if he could sell cookies in a can out of vending machines. In 2003, Kirkland received a patent for placing food and non-food items in a can to be dispensed from a vending machine. and also found that the military had developed a process for shelf-stable bread. Mark One Foods, LLC was formed in 2009 to market and produce Candwich. In 2010, the United States Securities and Exchange Commission filed a lawsuit against Travis L. Wright, a money manager who raised $145 million to invest in Mark One Foods, among other companies, when Wright had told investors that the money was for real estate investments. Wright had invested approximately $1 million into Mark One Foods. Wright was not part of Mark One Foods, just an investor, and the company was not charged with any wrongdoing. The Candwich is also being marketed for disaster preparedness and relief. On July 9, 2010, Stephen Colbert featured the Candwich in an episode of The Colbert Report.
Products
As of November 2011, the only flavor available is "Peanut Butter and Jelly - Grape", although the website claims that "Peanut Butter and Jelly - Strawberry" and "Barbecue Chicken" will be offered. Other potential ideas included pepperoni pizza pocket, French toast, and cinnamon rolls. A can of "Peanut Butter and Jelly - Grape" can contains "a small hoagie roll, a packet of peanut butter, a packet of jelly, a plastic knife and a handi-wipe" and a piece of Laffy Taffy. The Candwich had a one year shelf life. As of 2011, the Candwich was available online and at 7-11 stores in Salt Lake City, Utah. Starting September 15, 2016, Candwich could be pre-ordered via a crowdfunding campaign on In |
https://en.wikipedia.org/wiki/Valentin%20Rumyantsev | Valentin Vital'yevich Rumyantsev (ru: Валенти́н Вита́льевич Румя́нцев; 19 July 1921, in Novaya Skatovka, Saratov region – 10 June 2007, in Moscow) was a Russian engineer who played a crucial role in Soviet space program, mainly working on robotics and controls . He was a member of the Russian Academy of Sciences (1992), Department of Engineering, Mechanics and Control.
Career
Rumyantsev was professor in the Faculty of Mechanics and Mathematics in the Department of Theoretical Mechanics and Mecatronics at Moscow State University. He was editor of the Journal of Applied Mathematics and Mechanics (). Rumyantsev was also a corresponding member (1995) and member (2000) of the International Academy of Astronautics (France, Paris). |
https://en.wikipedia.org/wiki/Introsort | Introsort or introspective sort is a hybrid sorting algorithm that provides both fast average performance and (asymptotically) optimal worst-case performance. It begins with quicksort, it switches to heapsort when the recursion depth exceeds a level based on (the logarithm of) the number of elements being sorted and it switches to insertion sort when the number of elements is below some threshold. This combines the good parts of the three algorithms, with practical performance comparable to quicksort on typical data sets and worst-case O(n log n) runtime due to the heap sort. Since the three algorithms it uses are comparison sorts, it is also a comparison sort.
Introsort was invented by David Musser in , in which he also introduced introselect, a hybrid selection algorithm based on quickselect (a variant of quicksort), which falls back to median of medians and thus provides worst-case linear complexity, which is optimal. Both algorithms were introduced with the purpose of providing generic algorithms for the C++ Standard Library which had both fast average performance and optimal worst-case performance, thus allowing the performance requirements to be tightened. Introsort is in place and not stable.
Pseudocode
If a heapsort implementation and partitioning functions of the type discussed in the quicksort article are available, the introsort can be described succinctly as
procedure sort(A : array):
maxdepth ← ⌊log2(length(A))⌋ × 2
introsort(A, maxdepth)
procedure introsort(A, maxdepth):
n ← length(A)
if n < 16:
insertionsort(A)
else if maxdepth = 0:
heapsort(A)
else:
p ← partition(A) // assume this function does pivot selection, p is the final position of the pivot
introsort(A[1:p-1], maxdepth - 1)
introsort(A[p+1:n], maxdepth - 1)
The factor 2 in the maximum depth is arbitrary; it can be tuned for practical performance. denotes the array slice of items to including both and . The |
https://en.wikipedia.org/wiki/Ubiquitin-binding%20domain | Ubiquitin-binding domains (UBDs) are protein domains that recognise and bind non-covalently to ubiquitin through protein-protein interactions. As of 2019, a total of 29 types of UBDs had been identified in the human proteome. Most UBDs bind to ubiquitin only weakly, with binding affinities in the low to mid μM range. Proteins containing UBDs are known as ubiquitin-binding proteins or sometimes as "ubiquitin receptors".
Structure
Most UBDs are of small size (often less than 50 amino acids) and adopt many different protein folds from multiple fold classes, including all-alpha, all-beta, and alpha/beta folds. Many UBDs can be roughly classified into four broad categories: alpha-helical structures (in some cases as small as a single helix, as in the ubiquitin-interacting motif); zinc fingers; pleckstrin homology (PH) domains; and domains similar to those in ubiquitin-conjugating (also known as E2) enzymes. Other UBDs not fitting these categories can be SH3 domains, PFU domains, and other structures. Small helical structures are the most common, and examples include ubiquitin-associated domains (UBA), CUE domains, the ubiquitin-interacting motif (UIM), the motif interacting with ubiquitin (MIU), and the VHS protein domain.
Binding mechanism
Many UBDs of the UBA family bind to ubiquitin via a hydrophobic patch centred on a particular isoleucine residue (the "Ile44 patch"), although binding to other surface patches has been observed, for example the "Ile36 patch". Zinc finger UBDs have a broader range of binding modes including interactions with polar residues. Because many UBDs have a common or overlapping ubiquitin interaction surface, their interactions are often mutually exclusive; due to steric clashes, more than one UBD cannot physically interact with the same Ile44-centered hydrophobic patch on a single ubiquitin molecule.
Most UBDs described to date bind to monoubiquitin and thus do not show a linkage-preference for the differently linked ubiquitin chains. Ther |
https://en.wikipedia.org/wiki/Uniform%20polytope | In geometry, a uniform polytope of dimension three or higher is a vertex-transitive polytope bounded by uniform facets. The uniform polytopes in two dimensions are the regular polygons (the definition is different in 2 dimensions to exclude vertex-transitive even-sided polygons that alternate two different lengths of edges).
This is a generalization of the older category of semiregular polytopes, but also includes the regular polytopes. Further, star regular faces and vertex figures (star polygons) are allowed, which greatly expand the possible solutions. A strict definition requires uniform polytopes to be finite, while a more expansive definition allows uniform honeycombs (2-dimensional tilings and higher dimensional honeycombs) of Euclidean and hyperbolic space to be considered polytopes as well.
Operations
Nearly every uniform polytope can be generated by a Wythoff construction, and represented by a Coxeter diagram. Notable exceptions include the great dirhombicosidodecahedron in three dimensions and the grand antiprism in four dimensions. The terminology for the convex uniform polytopes used in uniform polyhedron, uniform 4-polytope, uniform 5-polytope, uniform 6-polytope, uniform tiling, and convex uniform honeycomb articles were coined by Norman Johnson.
Equivalently, the Wythoffian polytopes can be generated by applying basic operations to the regular polytopes in that dimension. This approach was first used by Johannes Kepler, and is the basis of the Conway polyhedron notation.
Rectification operators
Regular n-polytopes have n orders of rectification. The zeroth rectification is the original form. The (n−1)-th rectification is the dual. A rectification reduces edges to vertices, a birectification reduces faces to vertices, a trirectification reduces cells to vertices, a quadirectification reduces 4-faces to vertices, a quintirectification reduced 5-faces to vertices, and so on.
An extended Schläfli symbol can be used for representing rectified fo |
https://en.wikipedia.org/wiki/Carnegie%20stages | In embryology, Carnegie stages are a standardized system of 23 stages used to provide a unified developmental chronology of the vertebrate embryo.
The stages are delineated through the development of structures, not by size or the number of days of development, and so the chronology can vary between species, and to a certain extent between embryos. In the human being only the first 60 days of development are covered; at that point, the term embryo is usually replaced with the term fetus.
It was based on work by Streeter (1942) and O'Rahilly and Müller (1987). The name "Carnegie stages" comes from the Carnegie Institution of Washington.
While the Carnegie stages provide a universal system for staging and comparing the embryonic development of most vertebrates, other systems are occasionally used for the common model organisms in developmental biology, such as the Hamburger–Hamilton stages in the chick.
Stages
Days are approximate and reflect the days since the last ovulation before pregnancy ("Postovulatory age").
Stage 1: 1 days
fertilization
polar bodies
Carnegie stage 1 is the unicellular embryo. This stage is divided into three substages.
Stage 1 a
Primordial embryo. All the genetic material necessary for a new individual, along with some redundant chromosomes, are present within a single plasmalemma. Penetration of the fertilising sperm allows the oocyte to resume meiosis and the polar body is extruded.
Stage 1 b
Pronuclear embryo. Two separate haploid components are present - the maternal and paternal pronuclei. The pronuclei move towards each other and eventually compress their envelopes where they lie adjacent near the centre of the wall.
Stage 1 c
Syngamic embryo. The last phase of fertilisation. The pronuclear envelopes disappear and the parental chromosomes come together in a process called syngamy.
Stage 2: 2-3 days
cleavage
morula
compaction
Carnegie stage 2 begins when the zygote undergoes its first cell division, and ends when the blas |
https://en.wikipedia.org/wiki/Absolute%20risk | Absolute risk (or AR) is the probability or chance of an event. It is usually used for the number of events (such as a disease) that occurred in a group, divided by the number of people in that group.
Absolute risk is one of the most understandable ways of communicating health risks to the general public.
See also
Absolute risk reduction
Relative risk
Relative risk reduction
External links
Know Your Chances: Understanding Health Statistics |
https://en.wikipedia.org/wiki/Rocky%27s%20Boots | Rocky's Boots is an educational logic puzzle game by Warren Robinett and Leslie Grimm, published by The Learning Company in 1982. It was released for the Apple II, CoCo, Commodore 64, IBM PC and the IBM PCjr. It was followed by a more difficult sequel, Robot Odyssey. It won Software of the Year awards from Learning Magazine (1983), Parent's Choice magazine (1983), and Infoworld (1982, runner-up), and received the Gold Award (for selling 100,000 copies) from the Software Publishers Association. It was one of the first educational software products for personal computers to successfully use an interactive graphical simulation as a learning environment.
Gameplay
The object of the beginning part of Rocky's Boots is to use a mechanical boot to kick a series of objects (purple or green squares, diamonds, circles, or crosses) off a conveyor belt; each object will score some number of points, possibly negative. To ensure that the boot only kicks the positive objects, the player must connect a series of logic gates to the boot.
The player is represented by an orange square, and picks up devices (the boot, logic gates, clackers, etc.) by moving their square over them and hitting the joystick button. When the boot has kicked all of the positive objects and none of the negative objects (obtaining a score of 24 points), Rocky (a raccoon) will appear and do a beeping dance.
Later, the player finds that he can use all of the game's objects, including AND gates, OR gates, NOT gates, and flip-flops, in an open-ended area to design his own logic circuits and "games". The colors of orange and white were used to show the binary logic states of 1 and 0. As the circuits operated, the signals could be seen slowly propagating through the circuits, as if the electricity was liquid orange fire flowing through transparent pipes.
Development
Rocky's Boots was designed by Warren Robinett and Leslie Grimm. It was conceived as a sequel to Adventure. Robinett experienced constraints due to T |
https://en.wikipedia.org/wiki/Isochrone%20map | An isochrone map in geography and urban planning is a map that depicts the area accessible from a point within a certain time threshold. An isochrone (iso = equal, chrone = time) is defined as "a line drawn on a map connecting points at which something occurs or arrives at the same time". In hydrology and transportation planning isochrone maps are commonly used to depict areas of equal travel time. The term is also used in cardiology as a tool to visually detect abnormalities using body surface distribution.
History
Early examples of Isochrone maps include the Galton's Isochronic Postal Charts and Isochronic Passage Charts of 1881 and 1882, Bartholomew's Isochronic Distance Map and Chart first published 1889, and Albrecht Penck's Isochronenkarte first published 1887. Where as Galton and the Bartholomews published maps depicting the days or weeks it took to travel long distances, Albrecht further developed the idea to not only depict long distances and world travel but also smaller areas. Penck also created a series of maps that only depict the travel times of a certain transportation mode, for example Rail transport. Isochrone maps are commonly used in the UK in connection with development control. Isochrones are currently typically computed by via generating shortest-path trees on network graphs, and then generating a convex hull around the accessible nodes. Increases in computation, data storage, and improvements in algorithms have facilitated the rapid generation of isochrones. Recent techniques in visualization include linking travel times to network edges to show the paths accessible from a point rather than show the area accessible from a point.
Usage
Hydrology
Isochrone and related maps are used to show the time taken for runoff water within a drainage basin to reach a lake, reservoir or outlet, assuming constant and uniform effective rainfall. An early example of this method was demonstrated by Clark in 1945.
Transport planning
Isochrone maps have been |
https://en.wikipedia.org/wiki/List%20of%20food%20additives | Food additives are substances added to food to preserve flavor or enhance its taste, appearance, or other qualities.
Purposes
Additives are used for many purposes but the main uses are:
Acids Food acids are added to make flavors "sharper", and also act as preservatives and antioxidants. Common food acids include vinegar, citric acid, tartaric acid, malic acid, folic acid, fumaric acid, and lactic acid.
Acidity regulators Acidity regulators are used to change or otherwise control the acidity and alkalinity of foods.
Anticaking agents Anticaking agents keep powders such as milk powder from caking or sticking.
Antifoaming agents Antifoaming agents reduce or prevent foaming in foods.
Antioxidants Antioxidants such as vitamin C act as preservatives by inhibiting the effects of oxygen on food, and can be beneficial to health.
Bulking agents Bulking agents such as starch are additives that increase the bulk of a food without affecting its nutritional value.
Food coloring Colorings are added to food to replace colors lost during preparation, or to make food look more attractive.
Color retention agents In contrast to colorings, color retention agents are used to preserve a food's existing color.
Emulsifiers Emulsifiers allow water and oils to remain mixed together in an emulsion, as in mayonnaise, ice cream, and homogenized milk.
Flavors Flavors are additives that give food a particular taste or smell, and may be derived from natural ingredients or created artificially.
Flavor enhancers Flavor enhancers enhance a food's existing flavors. They may be extracted from natural sources (through distillation, solvent extraction, maceration, among other methods) or created artificially.
Flour treatment agents Flour treatment agents are added to flour to improve its color or its use in baking.
Glazing agents Glazing agents provide a shiny appearance or protective coating to foods.
Humectants Humectants prevent foods from drying out.
Tracer gas Tracer gas allow for pac |
https://en.wikipedia.org/wiki/Tropical%20night | A tropical night is a term used in many European countries to describe days when the temperature does not fall below during the nighttime. This definition is in use in countries including the United Kingdom, Republic of Ireland, Spain, Sweden, Norway, the Netherlands, Germany, Finland, Lithuania, Latvia, Hungary, Romania, Italy, Serbia, and Croatia. In the United States, by contrast, the term sultry nights is used when the temperature does not fall below in the Gulf and Atlantic states.
Tropical nights are common during heat waves and occur mostly over seas, coasts, and lakes. Heat gets stored in the water during periods of sunny and warm weather during the day, which is then emitted during the night and keeps the night temperatures up.
United Kingdom
The Met Office began tracking 'tropical nights' in 2018. This criterion is infrequently met, with the 30 years between 1961 and 1990 seeing 44 tropical nights, most of them associated with the hot summers of 1976 and 1983. From 1991 to 11 August 2020, 84 such nights were recorded, with 21 of them occurring since 2008. Five nights that stayed above 20 °C were recorded in 2018, and four in 2019. By 11 August 2020, four tropical nights had been recorded for that year, one in June and three in August.
During the July 2022 heatwave, a tropical night recorded overnight from 18–19 July was reported to have been the warmest on record, where temperatures in many parts of the country did not fall below 25°C. The hottest night on record was set in the early hours of 19 July 2022 at Shirburn Model Farm, Oxfordshire, not falling below 26.8°C, smashing the previous record of 23.9°C in the country. This was confirmed on 23 August 2022.
Croatia
In Croatia, this occurrence is usually termed 'warm night' (), but also ('tropical night'). A 'very warm night' () occurs when the temperature stays above overnight. Tropical nights happen regularly at the seaside in summer, and less frequently inland. In the 1961–1990 period, there wa |
https://en.wikipedia.org/wiki/Outline%20of%20ecology | The following outline is provided as an overview of and topical guide to ecology:
Ecology – scientific study of the distribution and abundance of living organisms and how the distribution and abundance are affected by interactions between the organisms and their environment. The environment of an organism includes both physical properties, which can be described as the sum of local abiotic factors such as solar insolation, climate and geology, as well as the other organisms that share its habitat. Also called ecological science.
Essence of ecology
, or
, or
, or
Other criteria
Ecology can also be classified on the basis of:
the primary kinds of organism under study, e.g. animal ecology, plant ecology, insect ecology;
the biomes principally studied, e.g. forest ecology, grassland ecology, desert ecology, benthic ecology, marine ecology, urban ecology;
the geographic or climatic area, e.g. arctic ecology, tropical ecology;
the spatial scale under consideration, e.g. macroecology, landscape ecology;
the philosophical approach, e.g. systems ecology which adopts a holistic approach;
the methods used, e.g. molecular ecology.
Subdisciplines of ecology, and subdiscipline classification
Ecology is a broad discipline comprising many subdisciplines. The field of ecology can be subdivided according to several classification schemes:
By methodology used for investigation
–
–
– the development of ecological theory, usually with mathematical, statistical and/or computer modeling tools.
By spatial scale of ecological system under study
–
–
.
By level of organisation or scope
Arranged from lowest to highest level of organisation:
– the study of individual organisms of a single species in relation to their environment;
– the study of homogenous or heterogenous groups of organisms in relation to their environment;
– the study of homogenous groups of organisms related as a single species;
– the study of heterogenous groups of organisms of multipl |
https://en.wikipedia.org/wiki/Control-flow%20graph | In computer science, a control-flow graph (CFG) is a representation, using graph notation, of all paths that might be traversed through a program during its execution. The control-flow graph was discovered by Frances E. Allen, who noted that Reese T. Prosser used boolean connectivity matrices for flow analysis before.
The CFG is essential to many compiler optimizations and static-analysis tools.
Definition
In a control-flow graph each node in the graph represents a basic block, i.e. a straight-line piece of code without any jumps or jump targets; jump targets start a block, and jumps end a block. Directed edges are used to represent jumps in the control flow. There are, in most presentations, two specially designated blocks: the entry block, through which control enters into the flow graph, and the exit block, through which all control flow leaves.
Because of its construction procedure, in a CFG, every edge A→B has the property that:
outdegree(A) > 1 or indegree(B) > 1 (or both).
The CFG can thus be obtained, at least conceptually, by starting from the program's (full) flow graph—i.e. the graph in which every node represents an individual instruction—and performing an edge contraction for every edge that falsifies the predicate above, i.e. contracting every edge whose source has a single exit and whose destination has a single entry. This contraction-based algorithm is of no practical importance, except as a visualization aid for understanding the CFG construction, because the CFG can be more efficiently constructed directly from the program by scanning it for basic blocks.
Example
Consider the following fragment of code:
0: (A) t0 = read_num
1: (A) if t0 mod 2 == 0
2: (B) print t0 + " is even."
3: (B) goto 5
4: (C) print t0 + " is odd."
5: (D) end program
In the above, we have 4 basic blocks: A from 0 to 1, B from 2 to 3, C at 4 and D at 5. In particular, in this case, A is the "entry block", D the "exit block" and lines 4 and 5 are jump targets. A graph |
https://en.wikipedia.org/wiki/Hinge%20theorem | In geometry, the hinge theorem (sometimes called the open mouth theorem) states that if two sides of one triangle are congruent to two sides of another triangle, and the included angle of the first is larger than the included angle of the second, then the third side of the first triangle is longer than the third side of the second triangle. This theorem is given as Proposition 24 in Book I of Euclid's Elements.
Scope and generalizations
The hinge theorem holds in Euclidean spaces and more generally in simply connected non-positively curved space forms.
It can be also extended from plane Euclidean geometry to higher dimension Euclidean spaces (e.g., to tetrahedra and more generally to simplices), as has been done for orthocentric tetrahedra (i.e., tetrahedra in which altitudes are concurrent) and more generally for orthocentric simplices (i.e., simplices in which altitudes are concurrent).
Converse
The converse of the hinge theorem is also true: If the two sides of one triangle are congruent to two sides of another triangle, and the third side of the first triangle is greater than the third side of the second triangle, then the included angle of the first triangle is larger than the included angle of the second triangle.
In some textbooks, the theorem and its converse are written as the SAS Inequality Theorem and the AAS Inequality Theorem respectively. |
https://en.wikipedia.org/wiki/Practical%20number | In number theory, a practical number or panarithmic number is a positive integer such that all smaller positive integers can be represented as sums of distinct divisors of . For example, 12 is a practical number because all the numbers from 1 to 11 can be expressed as sums of its divisors 1, 2, 3, 4, and 6: as well as these divisors themselves, we have 5 = 3 + 2, 7 = 6 + 1, 8 = 6 + 2, 9 = 6 + 3, 10 = 6 + 3 + 1, and 11 = 6 + 3 + 2.
The sequence of practical numbers begins
Practical numbers were used by Fibonacci in his Liber Abaci (1202) in connection with the problem of representing rational numbers as Egyptian fractions. Fibonacci does not formally define practical numbers, but he gives a table of Egyptian fraction expansions for fractions with practical denominators.
The name "practical number" is due to . He noted that "the subdivisions of money, weights, and measures involve numbers like 4, 12, 16, 20 and 28 which are usually supposed to be so inconvenient as to deserve replacement by powers of 10." His partial classification of these numbers was completed by and . This characterization makes it possible to determine whether a number is practical by examining its prime factorization. Every even perfect number and every power of two is also a practical number.
Practical numbers have also been shown to be analogous with prime numbers in many of their properties.
Characterization of practical numbers
The original characterisation by stated that a practical number cannot be a deficient number, that is one of which the sum of all divisors (including 1 and itself) is less than twice the number unless the deficiency is one. If the ordered set of all divisors of the practical number is with and , then Srinivasan's statement can be expressed by the inequality
In other words, the ordered sequence of all divisors of a practical number has to be a complete sub-sequence.
This partial characterization was extended and completed by and who showed that it is s |
https://en.wikipedia.org/wiki/Alexei%20Abrikosov%20%28physicist%29 | Alexei Alexeyevich Abrikosov (; June 25, 1928 – March 29, 2017) was a Soviet, Russian and American theoretical physicist whose main contributions are in the field of condensed matter physics. He was the co-recipient of the 2003 Nobel Prize in Physics, with Vitaly Ginzburg and Anthony James Leggett, for theories about how matter can behave at extremely low temperatures.
Education and early life
Abrikosov was born in Moscow, Russian SFSR, Soviet Union, on June 25, 1928, to a couple of physicians: Aleksey Abrikosov and Fani Abrikosova, née Wulf. His mother was Jewish. He graduated from Moscow State University in 1948. From 1948 to 1965, he worked at the Institute for Physical Problems of the USSR Academy of Sciences, where he received his Ph.D. in 1951 for the theory of thermal diffusion in plasmas, and then his Doctor of Physical and Mathematical Sciences (a "higher doctorate") degree in 1955 for a thesis on quantum electrodynamics at high energies. Abrikosov moved to the US in 1991 and lived there until his death in 2017, in Palo Alto, California. While in the US, Abrikosov was elected to the National Academy of Sciences in 2000, and in 2001, to be a foreign member of the Royal Society.
Career
From 1965 to 1988, he worked at the Landau Institute for Theoretical Physics (USSR Academy of Sciences). He has been a professor at Moscow State University since 1965. In addition, he held tenure at the Moscow Institute of Physics and Technology from 1972 to 1976, and at the Moscow Institute of Steel and Alloys from 1976 to 1991. He served as a full member of the USSR Academy of Sciences from 1987 to 1991. In 1991, he became a full member of the Russian Academy of Sciences.
In two works in 1952 and 1957, Abrikosov explained how magnetic flux can penetrate a class of superconductors. This class of materials are called type-II superconductors. The accompanying arrangement of magnetic flux lines is called the Abrikosov vortex lattice.
Together with Lev Gor'kov and Igor Dzyal |
https://en.wikipedia.org/wiki/Gravitational-wave%20observatory | A gravitational-wave detector (used in a gravitational-wave observatory) is any device designed to measure tiny distortions of spacetime called gravitational waves. Since the 1960s, various kinds of gravitational-wave detectors have been built and constantly improved. The present-day generation of laser interferometers has reached the necessary sensitivity to detect gravitational waves from astronomical sources, thus forming the primary tool of gravitational-wave astronomy.
The first direct observation of gravitational waves was made in September 2015 by the Advanced LIGO observatories, detecting gravitational waves with wavelengths of a few thousand kilometers from a merging binary of stellar black holes. In June 2023, four pulsar timing array collaborations presented the first strong evidence for a gravitational wave background of wavelengths spanning light years, most likely from many binaries of supermassive black holes.
Challenge
The direct detection of gravitational waves is complicated by the extraordinarily small effect the waves produce on a detector. The amplitude of a spherical wave falls off as the inverse of the distance from the source. Thus, even waves from extreme systems such as merging binary black holes die out to a very small amplitude by the time they reach the Earth. Astrophysicists predicted that some gravitational waves passing the Earth might produce differential motion on the order 10−18 m in a LIGO-size instrument.
Resonant mass antennas
A simple device to detect the expected wave motion is called a resonant mass antenna – a large, solid body of metal isolated from outside vibrations. This type of instrument was the first type of gravitational-wave detector. Strains in space due to an incident gravitational wave excite the body's resonant frequency and could thus be amplified to detectable levels. Conceivably, a nearby supernova might be strong enough to be seen without resonant amplification. However, up to 2018, no gravitational wave |
https://en.wikipedia.org/wiki/IBM%20BladeCenter | The IBM BladeCenter was IBM's blade server architecture, until it was replaced by Flex System in 2012. The x86 division was later sold to Lenovo in 2014.
History
Introduced in 2002, based on engineering work started in 1999, the IBM eServer BladeCenter was relatively late to the blade server market. It differed from prior offerings in that it offered a range of x86 Intel server processors and input/output (I/O) options.
The naming was changed to IBM BladeCenter in 2005. In February 2006, IBM introduced the BladeCenter H with switch capabilities for 10 Gigabit Ethernet and InfiniBand 4X.
A web site called Blade.org was available for the blade computing community through about 2009.
In 2012, the replacement Flex System was introduced.
Enclosures
IBM BladeCenter (E)
The original IBM BladeCenter was later marketed as BladeCenter E. Power supplies have been upgraded through the life of the chassis from the original 1200 to 1400, 1800, 2000 and 2320 watt.
The BladeCenter (E) was co-developed by IBM and Intel and included:
14 blade slots in 7U
Shared Media tray with Optical drive, floppy drive and USB 1.1 port
1 (upgradable to 2) Management modules
Two slots for Gigabit Ethernet switches (can also have optical or copper pass-through)
Two slots for optional switch or pass-through modules, can have additional Ethernet, Fibre Channel, InfiniBand or Myrinet 2000 functions
Power: Two (upgradable to four) power supplies, C19/C20 connectors
Two redundant high-speed blowers
IBM BladeCenter T
BladeCenter T is the telecommunications company version of the original BladeCenter, available with either AC or DC (48 V) power. Has 8 blade slots in 8U, but uses the same switches and blades as the regular BladeCenter E. To keep NEBS Level 3 / ETSI compliant special Network Equipment-Building System (NEBS) compliant blades are available.
IBM BladeCenter H
Upgraded BladeCenter design with high-speed fabric options, announced in 2006. Backwards compatible with older BladeCente |
https://en.wikipedia.org/wiki/Time-based%20one-time%20password | Time-based one-time password (TOTP) is a computer algorithm that generates a one-time password (OTP) that uses the current time as a source of uniqueness. As an extension of the HMAC-based one-time password algorithm (HOTP), it has been adopted as Internet Engineering Task Force (IETF) standard .
TOTP is the cornerstone of Initiative for Open Authentication (OATH), and is used in a number of two-factor authentication (2FA) systems.
History
Through the collaboration of several OATH members, a TOTP draft was developed in order to create an industry-backed standard. It complements the event-based one-time standard HOTP, and it offers end user organizations and enterprises more choice in selecting technologies that best fit their application requirements and security guidelines. In 2008, OATH submitted a draft version of the specification to the IETF. This version incorporates all the feedback and commentary that the authors received from the technical community based on the prior versions submitted to the IETF. In May 2011, TOTP officially became RFC 6238.
Algorithm
To establish TOTP authentication, the authenticatee and authenticator must pre-establish both the HOTP parameters and the following TOTP parameters:
T, the Unix time from which to start counting time steps (default is 0),
T, an interval which will be used to calculate the value of the counter C (default is 30 seconds).
Both the authenticator and the authenticatee compute the TOTP value, then the authenticator checks whether the TOTP value supplied by the authenticatee matches the locally generated TOTP value. Some authenticators allow values that should have been generated before or after the current time in order to account for slight clock skews, network latency and user delays.
TOTP uses the HOTP algorithm, replacing the counter with a non-decreasing value based on the current time:
TOTP value(K) = HOTP value(K, C),
calculating counter value
where
C is the count of the number of durations |
https://en.wikipedia.org/wiki/Microchromosome | A microchromosome is a chromosome defined for its relatively small size. They are typical components of the karyotype of birds, some reptiles, fish, amphibians, and monotremes. As many bird genomes have chromosomes of widely different lengths, the name was meant to distinguish them from the comparatively large macrochromosomes. The distinction referred to the measured size of the chromosome while staining for karyotype, and while there is not a strict definition, chromosomes resembling the large chromosomes of mammals were called macrochromosomes (roughly 3 to 6 µm), while the much smaller ones of less than around 0.5 µm were called microchromosomes. In terms of base pairs, by convention, those of less than 20Mb were called microchromosomes, those between 20 and 40 Mb are classified as intermediate chromosomes, and those larger than 40Mb are macrochromosomes. By this definition, all normal chromosomes in organisms with relatively small genomes (less than 100-200Mb) would be considered microchromosomes.
Function
Microchromosomes are characteristically very small and often cytogenetically indistinguishable in a karyotype, which makes ordering and identifying chromosomes into a coherent karyotype particularly difficult. While originally thought to be insignificant fragments of chromosomes, in species where they have been studied they have been found to be rich in genes and high in GC content. In chickens, microchromosomes have been estimated to contain between 50 and 75% of all genes. During metaphase, they appear merely as 0.5-1.5 μm long specks. Their small size and poor condensation into heterochromatin means they generally lack the diagnostic banding patterns and distinct centromere locations used for chromosome identification.
Occurrence
Microchromosomes are found in many vertebrates, but not in most mammals. Important comparisons were made using the genomic organization of the Florida lancelet – part of a sister group to all vertebrates – suggests that the an |
https://en.wikipedia.org/wiki/Bits%20of%20Freedom | Bits Of Freedom is an independent Dutch digital rights foundation, which focuses on privacy and communications freedom in the digital age. The foundation protects the right for privacy and the right to communications freedom in the Netherlands. Bits of Freedom started in 2000 and had a break between 2006 and August 2009 due to lack of funding. On August 14, 2009, Bits of Freedom continued its activities with funding provided by the Internet4All Foundation.
Bits of Freedom organizes the Dutch version of the Big Brother Awards, initiated European cooperation between digital rights watch foundations in European Digital Rights (EDRI) and collects information about data leaks in the Netherlands to raise awareness of the potential dangers of increasing collection of data.
The Multatuli Project
The Multatuli Project, subtitled ISP Notice and take down, was the title of an experiment done by members of the Bits of Freedom group in the summer of 2004. The group uploaded excerpts from Multatuli to websites hosted at 10 different Dutch ISPs, content which has been in the public domain since 1957. They then sent a complaint about the content from a Hotmail account posing as a legal advisor to the 10 ISPs; seven of them complied and removed the site, one within just three hours, without investigating the legality of the matter, or asking questions about the dubious background of the requester.
Big Brother Awards
To raise awareness of privacy-related issues, Bits of Freedom holds annual Big Brother Awards. This prize is awarded to businesses, governmental institutions and persons who have harmed privacy or increased civilian surveillance in the past year. The award is named after the character "Big Brother" from George Orwell's Nineteen Eighty-Four.
The winners of the Big Brother Awards 2011 were the National Police Services Agency (now the national police corps) (in the category "governmental institutions") for the use of spyware and hacking of hacking victims, minister Edi |
https://en.wikipedia.org/wiki/Interpersonal%20complementarity%20hypothesis | Interpersonal complementarity hypothesis asserts that individuals often behave in ways that evoke complementary or reciprocal behavior from others. More specifically, this hypothesis predicts that positive behaviors evoke positive behaviors, negative behaviors evoke negative behaviors, dominant behaviors evoke submissive behaviors, and vice versa.
Essentially, each action carried out by a member of a group has the ability to elicit predictable actions from other group members. For example, individuals who display evidence of positive behavior (e.g., smiling, behaving cooperatively) tend to trigger positively valenced behaviors from others. In much the same way, group members who behave in a docile or submissive fashion tend to elicit complementary, dominant behaviors from other members of the group. This behavioral congruency, as it applies to obedience and authority, has been illustrated in several studies assessing power hierarchies present in groups. These studies highlight the increased comfort experienced by individuals when the power or status behavior of others complement that of their own (e.g., a "leader" preferring a "follower").
See also
Interpersonal compatibility
Authority
Obedience (human behavior) |
https://en.wikipedia.org/wiki/Iterative%20impedance | Iterative impedance is the input impedance of an infinite chain of identical networks. It is related to the image impedance used in filter design, but has a simpler, more straightforward definition.
Definition
Iterative impedance is the input impedance of one port of a two-port network when the other port is connected to an infinite chain of identical networks. Equivalently, iterative impedance is that impedance that when connected to port 2 of a two-port network is equal to the impedance measured at port 1. This can be seen to be equivalent by considering the infinite chain of identical networks connected to port 2 in the first definition. If the original network is removed then port 1 of the second network will present the same iterative impedance as before since port 2 of the second network still has an infinite chain of networks connected to it. Thus the whole infinite chain can be replaced with a single lumped impedance equal to the iterative impedance, which is the condition for the second definition.
In general, the iterative impedance of port 1 is not equal to the iterative impedance of port 2. They will be equal if the network is symmetrical, however physically symmetry is not a necessary condition for the impedances to be equal.
Examples
A simple generic L-circuit is shown in the diagram consisting of a series impedance Z and a shunt admittance Y. The iterative impedance of this network, ZIT, in terms of its output load (also ZIT) is given by,
and solving for ZIT,
Another example is an L-circuit with the components reversed, that is, with the shunt admittance coming first. The analysis of this circuit can be found immediately through duality considerations of the previous example. The iterative admittance, YIT, of this circuit is given by,
where,
The square root term in these expressions cause them to have two solutions. However, only solutions with a positive real part are physically meaningful since passive circuits cannot exhibit nega |
https://en.wikipedia.org/wiki/Radiotrophic%20fungus | Radiotrophic fungi are fungi that can perform the hypothetical biological process called radiosynthesis, which means using ionizing radiation as an energy source to drive metabolism. It has been claimed that radiotrophic fungi have been found in extreme environments such as in the Chernobyl Nuclear Power Plant.
Most radiotrophic fungi use melanin in some capacity to survive. The process of using radiation and melanin for energy has been termed radiosynthesis, and is thought to be analogous to anaerobic respiration. However, it is not known if multi-step processes such as photosynthesis or chemosynthesis are used in radiosynthesis or even if radiosynthesis exists in living organisms.
Discovery
Many fungi have been isolated from the area around the destroyed Chernobyl Nuclear Power Plant, some of which have been observed directing their growth of hyphae toward radioactive graphite from the disaster, a phenomenon called “radiotropism”. Study has ruled out the presence of carbon as the resource attracting the fungal colonies, and in fact concluded that some fungi will preferentially grow in the direction of the source of beta and gamma ionizing radiation, but were not able to identify the biological mechanism behind this effect. It has also been observed that other melanin-rich fungi were discovered in the cooling water from some other, working, nuclear reactors. The light-absorbing compound in the fungus cell membranes had the effect of turning the water black. While there are many cases of extremophiles (organisms that can live in severe conditions such as that of the radioactive power plant), a hypothetical radiotrophic fungus would grow because of the radiation, rather than in spite of it.
Further research conducted at the Albert Einstein College of Medicine showed that three melanin-containing fungi—Cladosporium sphaerospermum, Wangiella dermatitidis, and Cryptococcus neoformans—increased in biomass and accumulated acetate faster in an environment in which the |
https://en.wikipedia.org/wiki/Ralph%20W.%20Gerard%20Prize%20in%20Neuroscience | The Ralph W. Gerard Award of the Society for Neuroscience (SfN) is an award in neuroscience awarded annually since 1978 for Lifetime Achievement. It is the highest recognition conferred by the SfN. As of 2018, the prize winner receives US$25,000.
It is named in memory of the American neurophysiologist Ralph Waldo Gerard (1900-1974), a founder and honorary president of the Society for Neuroscience and a professor at the University of Chicago , the University of Michigan and the University of California at Irvine. Gerard was known for his work on the nervous system, psychopharmacology, and biological basis of schizophrenia.
Recipients
1978 Stephen William Kuffler
1979 Roger Sperry
1980 Vernon Mountcastle
1981 Herbert Jasper
1982 , Clinton N. Woolsey
1983 Walle Nauta
1984 Theodore H. Bullock, Susumu Hagiwara
1985 Viktor Hamburger, Rita Levi-Montalcini
1986 Seymour Solomon Kety
1987 Brenda Milner
1988 Horace Winchell Magoun, Donald B. Lindsley
1989 Seymour Benzer
1990 Bernard Katz, Sanford L. Palay
1991 Bert Sakmann, Erwin Neher
1992 Julius Axelrod
1993 David Hubel, Torsten Wiesel
1994 Paul Greengard
1995 Hans Thoenen, Eric M. Shooter
1996 Louis Sokoloff
1997 Eric Kandel
1998 Edward R. Perl
1999 Charles F. Stevens
2000 Solomon Halbert Snyder
2001 William Maxwell Cowan
2002 Patricia Goldman-Rakic, Paško Rakić
2003 A. James Hudspeth
2004 Masakazu Konishi, Nobuo Suga
2005 Sten Grillner, Eve Marder
2006 Horace Barlow, Robert Henry Wurtz
2007 Friedrich Bonhoeffer, Nicole Marthe Le Douarin
2008 Mortimer Mishkin, Marcus Raichle
2009 Lily Jan, Yuh Nung Jan
2010 Ricardo Miledi
2011 Carla Shatz
2012 Colin Blakemore
2013 Carol A. Barnes
2014 Roger Andrew Nicoll, Richard Tsien
2015 Story Landis
2016 Ben Barres, Thomas Jessell
2017
2018 Rodolfo Llinas
2019 Michael E. Greenberg, Catherine Dulac
2020 György Buzsáki
2021 Richard L. Huganir
2022 Jon Kaas
See also
List of neuroscience awards
The Brain Prize
Golden Brain Award
The Kavli Prize in Neuroscience
W. Alden Spencer Awar |
https://en.wikipedia.org/wiki/European%20Journal%20of%20Taxonomy | The European Journal of Taxonomy is a peer-reviewed open access scientific journal for descriptive taxonomy of living and fossil eukaryotes, covering subjects in zoology, botany, and palaeontology. It is supported by the EJT Consortium, a group of European natural history institutes, which fully funds the publication. Therefore, the journal is free for both authors and readers (diamond open access).
History
The journal was initiated by a task force of people from the European Distributed Institute of Taxonomy network. The first article was published on 9 September 2011. In October 2015, the Consortium of European Taxonomic Facilities endorsed the journal.
Several older journals have been merged into the European Journal of Taxonomy:
Journal of Afrotropical Zoology
Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Entomologie
Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Biologie
Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre
Steenstrupia
Zoologische Mededelingen
Abstracting and indexing
The journal is abstracted and indexed in:
Biological Abstracts
BIOSIS Previews
CAB Abstracts
Current Contents/Agriculture, Biology & Environmental Sciences
Science Citation Index Expanded
The Zoological Record
According to the Journal Citation Reports, the journal has a 2020 impact factor of 1.372. |
https://en.wikipedia.org/wiki/Bluetooth%20mesh%20networking | Bluetooth Mesh is a computer mesh networking standard based on Bluetooth Low Energy that allows for many-to-many communication over Bluetooth radio. The Bluetooth Mesh specifications were defined in the Mesh Profile and Mesh Model specifications by the Bluetooth Special Interest Group (Bluetooth SIG). Bluetooth Mesh was conceived in 2014 and adopted on .
Overview
Bluetooth Mesh is a mesh networking standard that operates on a flood network principle. It's based on the nodes relaying the messages: every relay node that receives a network packet that authenticates against a known network key that is not in message cache, that has a TTL ≥ 2 can be retransmitted with TTL = TTL - 1. Message caching is used to prevent relaying messages recently seen.
Communication is carried in the messages that may be up to 384 bytes long, when using Segmentation and Reassembly (SAR) mechanism, but most of the messages fit in one segment, that is 11 bytes. Each message starts with an opcode, which may be a single byte (for special messages), 2 bytes (for standard messages), or 3 bytes (for vendor-specific messages).
Every message has a source and a destination address, determining which devices process messages. Devices publish messages to destinations which can be single things / groups of things / everything.
Each message has a sequence number that protects the network against replay attacks.
Each message is encrypted and authenticated. Two keys are used to secure messages: (1) network keys – allocated to a single mesh network, (2) application keys – specific for a given application functionality, e.g. turning the light on vs reconfiguring the light.
Messages have a time to live (TTL). Each time message is received and retransmitted, TTL is decremented which limits the number of "hops", eliminating endless loops.
Architecture
Bluetooth Mesh has a layered architecture, with multiple layers as below.
Topology
Nodes that support the various features can be formed into a mesh net |
https://en.wikipedia.org/wiki/OpenESB | OpenESB is a Java-based open-source enterprise service bus. It can be used as a platform for both enterprise application integration and service-oriented architecture. OpenESB allows developers to integrate legacy systems, external and internal partners and new development in business processes. It supports a multitude of integration technologies including standard JBI (Java Business Integration), XML with support for XML Schemas, WSDL, and BPEL with the aim of simplicity, efficiency, long-term durability, and low TCO (Total Cost of Ownership).
It used to be owned by Sun Microsystems, but after Oracle and Sun Microsystems merged (see: Sun acquisition by Oracle), the OpenESB Community was created to maintain, improve, promote and support OpenESB.
Architecture
OpenESB consists of 5 parts: the framework, the container, the components, the Integrated Development Environment and the development plugins.
Framework
The framework consists of a lightweight JBI implementation in Java. This implementation is container-agnostic and can work on any platform and any container. Even if development and support are mainly focused on Glassfish V2 and V3 platforms, beta projects on JBoss and standalone JVM work well and are in progress (2012 Q2). In addition to the OpenESB framework being lightweight, it is also reliable and highly scalable. It is embedded in a Java virtual machine and communicates with other framework instances through Binding components. This architecture matches perfectly with new cloud architectures and allows easy deployment and management on very complex infrastructures. The framework is fully manageable with any JMX-based tool such as Jconsole or more sophisticated tools like Opsview or Nagios.
The framework implements a virtual bus known as the Normalised Message Router (NMR). This is a powerful asynchronous intelligent communication channel between components.
Components
The JBI specification defines 2 component types: The services engine (SE) and the |
https://en.wikipedia.org/wiki/IUoU%20battery%20charging | IUoU is a DIN-designation (DIN 41773) for a lead-acid battery charging procedure that is also known as 3-stage charging, 3-phase charging, or 3-step charging. It consists of three phases (or stages), to be executed by a battery charger. The three phases are: I-phase (constant electric current), Uo-phase (constant over-voltage), and U-phase (constant voltage). The purpose is to fully charge the battery in a relatively short time without reducing its life span and to keep the battery charged indefinitely as long as the charger is connected.
Stages
Stage 1 is called the I-phase, constant-current stage, or bulk charge stage. This phase occurs when an IUoU charger is connected to a deeply discharged battery. The charger provides a constant current, typically the maximum current that the charger is capable of producing. As a result of this current, the battery absorbs a charge and its voltage rises. The charger limits the maximum voltage to Umax, a constant or temperature-dependent maximum, typically around 2.4 V per cell. Once the Umax voltage is reached, typically when the battery is charged to 70–80% of its capacity, the charger enters the Uo-phase. In case of a battery that is more than 80% full, this may happen immediately once the charger is switched on. Some chargers may keep the voltage at Umax for some time to allow the current to drop to 20% of the initial current value, before proceeding to the next stage.
Stage 2 is called the Uo-phase, constant-voltage boost stage, absorption stage, or topping charge.
In this stage, the battery is continued being charged at a constant (over)voltage Uo, but the charge current is decreasing. The decrease is imposed by the battery. The voltage in the Uo-phase is too high to be applied indefinitely (hence, overvoltage), but it allows charging the battery fully in a relatively short time. The Uo-phase is concluded when the charge current goes below a threshold Imin, after which the U-phase is entered. This happens when the bat |
https://en.wikipedia.org/wiki/Appendicitis | Appendicitis is inflammation of the appendix. Symptoms commonly include right lower abdominal pain, nausea, vomiting, and decreased appetite. However, approximately 40% of people do not have these typical symptoms. Severe complications of a ruptured appendix include widespread, painful inflammation of the inner lining of the abdominal wall and sepsis.
Appendicitis is primarily caused by a blockage of the hollow portion in the appendix. This blockage typically results from a calcified "stone" made of feces. Other factors such as inflamed lymphoid tissue from a viral infection, intestinal parasites, gallstone, or tumors may also lead to this blockage. When the appendix becomes blocked, it experiences increased pressure, reduced blood flow, and bacterial growth, resulting in inflammation. This combination of factors causes tissue injury and, ultimately, tissue death. If this process is left untreated, it can lead to the appendix rupturing, which releases bacteria into the abdominal cavity, potentially leading to severe complications.
The diagnosis of appendicitis is largely based on the person's signs and symptoms. In cases where the diagnosis is unclear, close observation, medical imaging, and laboratory tests can be helpful. The two most commonly used imaging tests for diagnosing appendicitis are ultrasound and computed tomography (CT scan). CT scan is more accurate than ultrasound in detecting acute appendicitis. However, ultrasound may be preferred as the first imaging test in children and pregnant women because of the risks associated with radiation exposure from CT scans.
The standard treatment for acute appendicitis involves the surgical removal of the inflamed appendix. This procedure can be performed either through an open incision in the abdomen (laparotomy) or using minimally invasive techniques with small incisions and cameras (laparoscopy). Surgery is essential to reduce the risk of complications or potential death associated with the rupture of the app |
https://en.wikipedia.org/wiki/Pendred%20syndrome | Pendred syndrome is a genetic disorder leading to congenital bilateral (both sides) sensorineural hearing loss and goitre with euthyroid or mild hypothyroidism (decreased thyroid gland function). There is no specific treatment, other than supportive measures for the hearing loss and thyroid hormone supplementation in case of hypothyroidism. It is named after Vaughan Pendred (1869–1946), the British doctor who first described the condition in an Irish family living in Durham in 1896. It accounts for 7.5% to 15% of all cases of congenital deafness.
Signs and symptoms
The hearing loss of Pendred syndrome is often, although not always, present from birth, and language acquisition may be a significant problem if deafness is severe in childhood. The hearing loss typically worsens over the years, and progression can be step-wise and related to minor head trauma. In some cases, language development worsens after head injury, demonstrating that the inner ear is sensitive to trauma in Pendred syndrome; this is as a consequence of the widened vestibular aqueducts usual in this syndrome. Vestibular function varies in Pendred syndrome and vertigo can be a feature of minor head trauma. A goitre is present in 75% of all cases.
Genetics
Pendred syndrome is inherited in an autosomal recessive manner, meaning that one would need to inherit an abnormal gene from each parent to develop the condition. This also means that a sibling of a patient with Pendred syndrome has a 25% chance of also having the condition if the parents are unaffected carriers.
It has been linked to mutations in the PDS gene, which codes for the pendrin protein (solute carrier family 26, member 4, SLC26A4). The gene is located on the long arm of chromosome 7 (7q31). Mutations in the same gene also cause enlarged vestibular aqueduct syndrome (EVA or EVAS), another congenital cause of deafness; specific mutations are more likely to cause EVAS, while others are more linked with Pendred syndrome.
Pathophysiology
|
https://en.wikipedia.org/wiki/Chrome%20S20%20series | Chrome 20 Series is a graphics accelerator by S3 Graphics, the successor of GammaChrome S18.
Overview
The Chrome 20 series was introduced on March 11, 2005, with the Chrome S25 and Chrome S27 as launch products. Similar to the GammaChrome S18 PCI Express which preceded it, S20 was marketed to the low and mid range of the graphics card market, with the Chromotion 3 Video Engine and low power consumption as main selling points.
The S20 series marked S3's first products utilizing Fujitsu's 90 nm process. This enabled a significant increase in clock speeds over prior S3 products, and the Chrome 20 series could use 32-256MiB GDDR1 or GDDR3 memory at maximum if 700 MHz, or 64-512MiB GDDR2 memory at a maximum of 500 MHz. The S20 was also S3's first GDDR3 enabled product - with the memory interface supporting 32, 64, or 128-bit of GDDR1, GDDR2 or GDDR3 memory.
Similar to Radeon X1000 series, texturing units and raster operators are separated from pixel shaders. Chrome 20 has 4 vertex shaders, 8 pixel shaders, 4 texturing units, 4 raster operators.
Display controller now integrates a single-link TMDS transmitter, with support of dual-link using external transmitters.
Other new features supports the multi-GPU technology MultiChrome and AcceleRAM.
Chromotion 3.0
This revision of Chromotion Engine adds support of nonlinear video scaling, commonly used by wide screen television sets. TV encoder now supports 18 DTV ATSC formats:
MultiChrome
MultiChrome is a technique to couple multiple graphics chips for better performance. It was first used in the Chrome S20 series and later in Chrome 400 series graphics processors. The methods used by MultiChome are Alternate frame rendering and Split Frame Rendering. The technology is comparable to NVidia's SLI and ATi/AMD's Crossfire multi video adapter solution.
At the moment, due to the speed of the Chrome S20 and Chrome 400 chipsets, no special connectors are required to bridge both cards to activate MultiChrome. Also, unlike NVid |
https://en.wikipedia.org/wiki/Chemotronics | Chemotronics is an intersection field of chemistry (especially electrochemistry) and electronics dealing with the design of electrochemical and optical chemical sensors. One of pioneers of this field was Alexander Frumkin.
See also
Amperostat
Bioelectrochemistry
Bioelectronics
Electrochemical engineering
Potentiostat
Notes
External links
IEEE
Analytical chemistry
Sensors |
https://en.wikipedia.org/wiki/Rare%20breed | In modern agriculture, a rare breed is a breed of poultry or livestock that has a very small breeding population, usually from a few hundred to a few thousand. Because of their small numbers, rare breeds may have a threatened conservation status, and they may be protected under regional laws. Many countries have organizations devoted to the protection and promotion of rare breeds, for which they each have their own definition. In botany and horticulture, the parallel to rare animal breeds are heirloom plants, which are rare cultivars.
Definitions
There are several definitions of "breed" and "rare breed". Breeds may be defined as a group of animals that share visible characteristics, such as Pinto horses, which are all spotted. A stricter definition insists that breeds are "consistent and predictable genetic entities", which means that individuals from that breed will produce offspring that is predictably similar to their genitors, and that this similarity is genetically based. This biological definition is useful for conservation, which treats breeds as reliable sources of genetic diversity.
Conservation organisations each have their own definition of what constitutes a rare breed. The Rare Breeds Survival Trust (RBST) and The Livestock Conservancy (TLC) both divide rare breeds into five categories, "critical" being the rarest. TLC places a livestock breed under "critical" status when it has "fewer than 200 annual registrations in the United States and estimated global population less than 2,000". The RBST determines the status of a breed by the number of its breeding females in the United Kingdom. For horses and sheep, fewer than 300 is considered "critical", whereas goats and pigs must have fewer than 100 to join that category.
The Poultry Club of Great Britain considers a poultry breed "Rare" when it does not have its own breed club. These "Rare Breeds" are catered by the Rare Poultry Society (RPS). The RPS does not look after breeds that count few individual |
https://en.wikipedia.org/wiki/Milanuncios | Milanuncios.com is a Spanish website used for online classified advertisements.
The service of Milanuncios consists in the insertion of ads, created by the users of the website, in the portal milanuncios.com. This way Milanuncios helps to connect advertisers with those interested in the ad.
So far, the company has only focused on the Spanish market.
In 2014, Milanuncios SL was acquired by Schibsted.
Description
Milanuncios is divided into 16 different sections:
Motor
Jobs
Real Estate
Pets
Services
Businesses
Computers
Phones
House and Garden
Sports
Image and Sound
Fashion
Hobbies
Books and Education
Contacts.
The posting of ads on the website is completely free of charge both for individuals and for professionals/companies. There is no limit as to how many ads can be posted as long as the Terms and conditions are being respected.
Milanuncios' most important section is Motor followed by Goods. With 372k vehicle ads in August 2012, Milanuncios has the most complete offering in the Spanish market, well ahead of its competitors segundamano.es with 246k ads, and also the specialized motors vertical coches.net (120k ads).
Milanuncios helps to connect advertisers with those interested in the ad but does not mediate between the parties. Therefore, users need to be cautious in their interactions and transactions. As a general norm, the webpage recommends not to pay before receiving the product or service and users should meet in person to close the transaction. The website offers a series of simple filters to facilitate local searches.
Competitors
The main competitors of Milanuncios are vibbo.com (former segundamano.es and Milanuncios has bought this website), tablondeanuncios.com , clasf.es anuncios.ebay.es, wallapop.com, poneranuncios.com, anuncialoquequieras.com, mundoanuncio.com and campusanuncios.com.
Milanuncios.com has a market share of around 50% followed by segundamano.es with a share close to 30% in June 2012.
Segundamano was bought by |
https://en.wikipedia.org/wiki/Myokine | A myokine is one of several hundred cytokines or other small proteins (~5–20 kDa) and proteoglycan peptides that are produced and released by skeletal muscle cells (muscle fibers) in response to muscular contractions. They have autocrine, paracrine and/or endocrine effects; their systemic effects occur at picomolar concentrations.
Receptors for myokines are found on muscle, fat, liver, pancreas, bone, heart, immune, and brain cells. The location of these receptors reflects the fact that myokines have multiple functions. Foremost, they are involved in exercise-associated metabolic changes, as well as in the metabolic changes following training adaptation. They also participate in tissue regeneration and repair, maintenance of healthy bodily functioning, immunomodulation; and cell signaling, expression and differentiation.
History
The definition and use of the term myokine first occurred in 2003.
In 2008, the first myokine, myostatin, was identified. The gp130 receptor cytokine IL-6 (Interleukin 6) was the first myokine found to be secreted into the blood stream in response to muscle contractions.
Functions
In repetitive skeletal muscle contractions
There is an emerging understanding of skeletal muscle as a secretory organ, and of myokines as mediators of physical fitness through the practice of regular physical exercise (aerobic exercise and strength training), as well as new awareness of the anti-inflammatory and thus disease prevention aspects of exercise. Different muscle fiber types – slow twitch muscle fibers, oxidative muscle fibers, intermediate twitch muscle fibers, and fast twitch muscle fibers – release different clusters of myokines during contraction. This implies that variation of exercise types, particularly aerobic training/endurance training and muscle contraction against resistance (strength training) may offer differing myokine-induced benefits.
"Some myokines exert their effects within the muscle itself. Thus, myostatin, LIF, IL-6 and IL-7 ar |
https://en.wikipedia.org/wiki/Raoul%20Bott | Raoul Bott (September 24, 1923 – December 20, 2005) was a Hungarian-American mathematician known for numerous foundational contributions to geometry in its broad sense. He is best known for his Bott periodicity theorem, the Morse–Bott functions which he used in this context, and the Borel–Bott–Weil theorem.
Early life
Bott was born in Budapest, Hungary, the son of Margit Kovács and Rudolph Bott. His father was of Austrian descent, and his mother was of Hungarian Jewish descent; Bott was raised a Catholic by his mother and stepfather. Bott grew up in Czechoslovakia and spent his working life in the United States. His family emigrated to Canada in 1938, and subsequently he served in the Canadian Army in Europe during World War II.
Career
Bott later went to college at McGill University in Montreal, where he studied electrical engineering. He then earned a PhD in mathematics from Carnegie Mellon University in Pittsburgh in 1949. His thesis, titled Electrical Network Theory, was written under the direction of Richard Duffin. Afterward, he began teaching at the University of Michigan in Ann Arbor. Bott continued his study at the Institute for Advanced Study in Princeton. He was a professor at Harvard University from 1959 to 1999. In 2005 Bott died of cancer in San Diego.
With Richard Duffin at Carnegie Mellon, Bott studied existence of electronic filters corresponding to given positive-real functions. In 1949 they proved a fundamental theorem of filter synthesis. Duffin and Bott extended earlier work by Otto Brune that requisite functions of complex frequency s could be realized by a passive network of inductors and capacitors. The proof relied on induction on the sum of the degrees of the polynomials in the numerator and denominator of the rational function.
In his 2000 interview with Allyn Jackson of the American Mathematical Society, he explained that he sees "networks as discrete versions of harmonic theory", so his experience with network synthesis and electroni |
https://en.wikipedia.org/wiki/Kleptotype | In taxonomy, a kleptotype is an unofficial term referring to a stolen, unrightfully displaced type specimen or part of a type specimen.
Etymology
The term is composed of klepto-, from the Ancient Greek (kléptō) meaning "to steal", and -type referring to type specimens. It translates to "stolen type".
History
During the second world war biological collections, like the herbarium in Berlin have been destroyed. This led to the loss of type specimens. In some cases only kleptotypes have survived the destruction, as the type material had been removed from their original collections. For instance, the type of Taxus celebica was thought to be destroyed during the second world war, but a kleptotype has survived the war in Stockholm.
Kleptotypes have been taken by researchers, who subsequently added their unauthorised type duplicates to their own collections.
Consequences
Taking kleptotypes has been criticised as destructive, wasteful, and unethical. The displacement of type material complicates the work of taxonomists, as species identities may become ambiguous due to the lacking type material. It can cause problems, as researchers have to search in multiple collections to get a complete perspective on the displaced material. To combat this issue it has been proposed to weigh specimens before loaning types, and to identify loss of material through comparing the types weight upon return. Also, in some herbaria, such as the herbarium Kew, specimens are glued to the herbarium sheets to hinder the removal of plant material. However, this also makes it difficult to handle the specimens.
Rules concerning type specimens
The International Code of Nomenclature for algae, fungi, and plants (ICN) does not explicitly prohibit the removal of material from type specimens, however it strongly recommends to conserve the type specimens properly. It is paramount that types remain intact, as they are an irreplaceable resource and point of reference. |
https://en.wikipedia.org/wiki/Twilight | Twilight is light produced by sunlight scattering in the upper atmosphere, when the Sun is below the horizon, which illuminates the lower atmosphere and the Earth's surface. The word twilight can also refer to the periods of time when this illumination occurs.
The lower the Sun is beneath the horizon, the dimmer the twilight (other factors such as atmospheric conditions being equal). When the Sun reaches 18° below the horizon, the twilight's brightness is nearly zero, and evening twilight becomes nighttime. When the Sun again reaches 18° below the horizon, nighttime becomes morning twilight. Owing to its distinctive quality, primarily the absence of shadows and the appearance of objects silhouetted against the lit sky, twilight has long been popular with photographers and painters, who often refer to it as the blue hour, after the French expression l'heure bleue.
By analogy with evening twilight, the word twilight is also sometimes used metaphorically, to imply that something is losing strength and approaching its end. For example, very old people may be said to be "in the twilight of their lives". The collateral adjective for twilight is crepuscular, which may be used to describe the behavior of animals that are most active during this period.
Definitions by geometry
Twilight is defined according to the solar elevation angle θs, which is the position of the geometric center of the Sun relative to the horizon. There are three established and widely accepted subcategories of twilight: civil twilight (nearest the horizon), nautical twilight, and astronomical twilight (farthest from the horizon).
Civil twilight
Civil twilight is defined as when the geometric center of the Sun is between 6° below the horizon and the horizon itself.
Civil twilight is the period when enough natural light remains that artificial light in towns and cities is not needed. In the United States' military, the initialisms BMCT (begin morning civil twilight, i.e., civil dawn) and EECT (end |
https://en.wikipedia.org/wiki/W.%20V.%20D.%20Hodge | Sir William Vallance Douglas Hodge (; 17 June 1903 – 7 July 1975) was a British mathematician, specifically a geometer.
His discovery of far-reaching topological relations between algebraic geometry and differential geometry—an area now called Hodge theory and pertaining more generally to Kähler manifolds—has been a major influence on subsequent work in geometry.
Life and career
Hodge was born in Edinburgh in 1903, the younger son and second of three children of Archibald James Hodge (1869-1938), a searcher of records in the property market and a partner in the firm of Douglas and Company, and his wife, Jane (born 1875), daughter of confectionery business owner William Vallance. They lived at 1 Church Hill Place in the Morningside district.
He attended George Watson's College, and studied at Edinburgh University, graduating MA in 1923. With help from E. T. Whittaker, whose son J. M. Whittaker was a college friend, he then took the Cambridge Mathematical Tripos. At Cambridge he fell under the influence of the geometer H. F. Baker. He gained a Cambridge BA degree in 1925, receiving the MA in 1930 and the Doctor of Science (ScD) degree in 1950.
In 1926 he took up a teaching position at the University of Bristol, and began work on the interface between the Italian school of algebraic geometry, particularly problems posed by Francesco Severi, and the topological methods of Solomon Lefschetz. This made his reputation, but led to some initial scepticism on the part of Lefschetz. According to Atiyah's memoir, Lefschetz and Hodge in 1931 had a meeting in Max Newman's rooms in Cambridge, to try to resolve issues. In the end Lefschetz was convinced.
In 1928 he was elected a Fellow of the Royal Society of Edinburgh. His proposers were Sir Edmund Taylor Whittaker, Ralph Allan Sampson, Charles Glover Barkla, and Sir Charles Galton Darwin. He was awarded the Society's Gunning Victoria Jubilee Prize for the period 1964 to 1968.
In 1930 Hodge was awarded a Research Fellowship |
https://en.wikipedia.org/wiki/KAT-7 | KAT-7 is a radio telescope situated in the Meerkat National Park, in the Northern Cape of South Africa. Developed as the precursor engineering test bed to the larger MeerKAT telescope, previously known as Karoo Array Telescope (KAT), it has become a science instrument in its own right. The construction was completed in 2011 and commissioning in 2012. It also served as a technology demonstrator for South Africa's bid to host the Square Kilometre Array. KAT-7 is the first Radio telescope to be built with a composite reflector and uses a stirling pump for 75 K cryogenic cooling. The telescope was built to test various system for the MeerKAT array, from the ROACH correlators designed and manufactured in Cape Town, now used by various telescopes internationally, to composite construction techniques.
Technical specifications
KAT-7 consist of 7 dishes of 12 metres in diameter, each a prime focus reflecting telescope.
Performance
In April 2010 four of the seven dishes were linked together as an integrated system to produce its first interferometric image of an astronomical object. In Dec 2010, there was a successful detection of very long baseline interferometry (VLBI) fringes between the Hartebeesthoek Radio Astronomy Observatory's 26 m dish and one of the KAT-7 dishes.
See also
Australian Square Kilometre Array Pathfinder
Hartebeesthoek Radio Astronomy Observatory
List of radio telescopes
South African Astronomical Observatory for optical astronomy in South Africa
Precision Array for Probing the Epoch of Reionization |
https://en.wikipedia.org/wiki/Network%20enumeration | Network enumeration is a computing activity in which usernames and info on groups, shares, and services of networked computers are retrieved. It should not be confused with network mapping, which only retrieves information about which servers are connected to a specific network and what operating system runs on them.
Network enumeration is the discovery of hosts or devices on a network. Network enumeration tends to use overt discovery protocols such as ICMP and SNMP to gather information. It may also scan various ports on remote hosts for looking for well known services in an attempt to further identify the function of a remote host. The next stage of enumeration is to fingerprint the operating system of the remote host.
Software
A network enumerator or network scanner is a computer program used to retrieve usernames and info on groups, shares, and services of networked computers. This type of program scans networks for vulnerabilities in the security of that network. If there is a vulnerability with the security of the network, it will send a report back to a hacker who may use this info to exploit that network glitch to gain entry to the network or for other malicious activities. Ethical hackers often also use the information to remove the glitches and strengthen their network.
Malicious (or "black-hat") hackers can, on entry of the network, get to security-sensitive information or corrupt the network making it useless. If this network belonged to a company which used this network on a regular basis, the company would lose the function to send information internally to other departments.
Network enumerators are often used by script kiddies for ease of use, as well as by more experienced hackers in cooperation with other programs/manual lookups. Also, whois queries, zone transfers, ping sweeps, and traceroute can be performed.
List of network enumerators
Metasploit Project
Nmap
Nessus
OpenVAS
SAINT (software)
Security Administrator Tool for Analyzing Networks
Z |
https://en.wikipedia.org/wiki/AdBrite | AdBrite, Inc. was an online ad exchange, based in San Francisco, California, which was founded by Philip J. Kaplan and Gidon Wise in 2002. Founded as Marketbanker.com, the site was relaunched as AdBrite in 2004 as an advertising network and then in 2008 as an ad exchange.
AdBrite remained an independent ad exchange, reaching more than 160 million U.S. unique visitors each month and providing site-level transparency, display and video capabilities, and an open platform for data providers and real-time bidders. AdBrite was led by Hardeep Bindra, CEO, and Joaquin Delgado, CTO, who had worked at Yahoo! Right Media, another ad exchange. It was backed by Sequoia Capital, and DAG Ventures.
Closing
In 2012, Hardeep Bindra joined AdBrite as its CEO and was tasked to sell the company or its assets. On January 28, 2013, AdBrite sent an email to all of its publishers and advertisers stating that it would cease operations as of February 1, 2013, after a deal to sell the company fell through. In addition, it laid off all 26 employees.
Acquisition of IP Assets
On June 20, 2013 SiteScout announced via press release the acquisition of certain intellectual property assets developed by AdBrite in a deal whose details remain confidential.
See also
Ad serving
Advertising network
Pay-per-click
Website monetization |
https://en.wikipedia.org/wiki/Laticifer | A laticifer is a type of elongated secretory cell found in the leaves and/or stems of plants that produce latex and rubber as secondary metabolites. Laticifers may be divided into:
Articulated laticifers, i.e., composed of a series of cells joined together, or
Non-articulated laticifers, consisting of one long coenocytic cell.
Non-articulated laticifers begin their growth from the meristematic tissue of the embryo, termed the laticifer initial, and can exhibit continual growth throughout the lifetime of the plant. Laticifer tubes have irregularly edged walls and a larger inner diameter than the surrounding parenchyma cells. In the development of the cell, elongation occurs via karyokinesis and no cell plate develops resulting in coenocytic cells which extend throughout the plant. These cells can reach up to tens of centimeters long and can be branched or unbranched.
They are thought to have a role in wound healing and as defense against herbivory, as well as pathogen defense, and are often used for taxonomy.
Laticifers were first described by Anton de Bary in 1877.
Laticifers are highly specialized cells which can produce a wide variety of proteins. These proteins include enzymes functioning as proteinases and chitinases which help defend the producing plant against insects and other herbivores. In one study it was found that the presence and concentration of some proteins can differ greatly within the genus Croton relative to three species studied.
Cell Turgor
Pressurized flow of latex has been studied in multiple Asclepias species as a form of defense in addition to the secondary metabolites stored in the latex. In order to augment the defense of the plant some non-articulated laticifer cells contain highly pressurized stores of latex. It has been noted that pressure may be produced by the osmotic uptake of water into the laticifer cell resulting in a turgid cell. When pierced the cell bursts and latex travels quickly through the canal system to stop the her |
https://en.wikipedia.org/wiki/Animal%20identification | Animal identification using a means of marking is a process done to identify and track specific animals. It is done for a variety of reasons including verification of ownership, biosecurity control, and tracking for research or agricultural purposes.
History
Individual identification of animals by means of body markings has been practiced for over 3,800 years, as stated in Code of Hammurabi. The first official identification systems are documented as far as the 18th century. In Uruguay for instance maintained at that time a register of hot brands.
Methods
Biometrics
Birds
Leg rings
Wing tags
Microchip implants (parrots)
Telemetry (falconry birds)
Sheep
Freeze branding
Branding (hot-iron)
Collar
Earmarking
Ear tags (non-electronic)
Ear tags (electronic)
Semi-permanent paint
Pigs
Collars (electronic and non-electronic)
Earmarking
Ear tags (non-electronic)
Ear tags (electronic)
Semi-permanent paint
Tattoo
Horses
Collars (non-electronic)
Branding (hot-iron)
Branding (freeze)
Microchip implants
Lip tattoo
Cattle
Anklets
Branding (freeze)
Branding (hot-iron)
Collars (electronic and non-electronic)
Earmarking
Ear tags (non-electronic)
Ear tags (electronic)
Rumen bolus (electronic)
Cowbell
Dogs
Collar
Microchip implants
Tattoo
Laboratory mice
Earmarking (notching or punching)
Ear tags (nickel, copper or scannable 2D barcode tags)
Microchip implants
Hair dye
Toe clipping
Manual tattoos (tail, foot pad or ears)
Automated tail tattoos
Fish
Microchip implants
Fin clipping
Coded wire tag
Passive integrated transponder
Acoustic tag
Visible implant elastomer (VIE)
Marine mammals
Transponders
Adhesive tags
Amphibians
Microchip implants
Toe clippings
Passive integrated transponder
Visible implant elastomer (VIE)
Invertebrates
Adhesive tags
Semi-permanent paint
National animal identification schemes
British Cattle Movement Service in Britain
National Animal Identification and Tracing in New Zealand
National Anima |
https://en.wikipedia.org/wiki/Histoplasmosis | Histoplasmosis is a fungal infection caused by Histoplasma capsulatum. Symptoms of this infection vary greatly, but the disease affects primarily the lungs. Occasionally, other organs are affected; called disseminated histoplasmosis, it can be fatal if left untreated.
Histoplasmosis is common among AIDS patients because of their suppressed immunity. In immunocompetent individuals, past infection results in partial protection against ill effects if reinfected.
Histoplasma capsulatum is found in soil, often associated with decaying bat guano or bird droppings. Disruption of soil from excavation or construction can release infectious elements that are inhaled and settle into the lung.
From 1938 to 2013 in the US, 105 outbreaks were reported in a total of 26 states plus Puerto Rico. In 1978 to 1979 during a large urban outbreak in which 100,000 people were exposed to the fungus in Indianapolis, victims had pericarditis, rheumatological syndromes, esophageal and vocal cord ulcers, parotitis, adrenal insufficiency, uveitis, fibrosing mediastinitis, interstitial nephritis, intestinal lymphangiectasia, and epididymitis. Histoplasmosis mimics colds, pneumonia, and the flu, and can be shed by bats in their feces.
Signs and symptoms
If symptoms of histoplasmosis infection occur, they start within 3 to 17 days after exposure; the typical time is 12–14 days. Most affected individuals have clinically silent manifestations and show no apparent ill effects. The acute phase of histoplasmosis is characterized by nonspecific respiratory symptoms, often cough or flu-like. Chest X-ray findings are normal in 40–70% of cases. Chronic histoplasmosis cases can resemble tuberculosis; disseminated histoplasmosis affects multiple organ systems and is fatal unless treated.
While histoplasmosis is the most common cause of mediastinitis, this remains a relatively rare disease. Severe infections can cause hepatosplenomegaly, lymphadenopathy, and adrenal enlargement. Lesions often left calc |
https://en.wikipedia.org/wiki/Vu%2B | The Vu+ (pronounced VuPlus), is a series of Linux-powered DVB satellite, terrestrial digital television receivers (set-top box), produced by Korean multimedia brand Ceru Co., Ltd.
History and description
All older Vu+ hardware set-top boxes are MIPS-powered, newer are all ARM-powered and uses Enigma2 image based software as firmware.
Its firmware is officially user-upgradable, since it is a Linux-based computer, as opposed to third-party "patching" of alternate receivers. Firmware is based on Enigma 2, which was originally designed for Dreambox by Dream Multimedia. All units support Conax conditional access (CA) system, with software-emulated conditional-access modules (CAMs) available for many alternate CA systems. The built-in Ethernet interface allows networked computers to access the recordings on the internal hard disks and stream live picture from the tuners. It also enables the receiver to store digital copies of DVB MPEG transport streams on networked filesystems or broadcast the streams as IPTV to VideoLAN and XBMC Media Center clients. Unlike many PC based PVR systems that use free-to-air type of DVB receiver cards, the built-in conditional access allows receiving and storing encrypted content.
In the beginning of September in 2011, Dream Multimedia obtained a temporary injunction against the Satco Europe GmbH company for using their "Enigma 2" name in an advertising flyer to promote the Linux operating system installed on the Vu+ set-top-boxes, as "Enigma"(2) is a registered trademark name of Dream Multimedia GmbH.
Models
Note that Vu+ Uno and Vu+ Ultimo have a dual core processor BCM7413.
* in most cases Solo is underclocked to 220.67MHz
*** in Solo SE standard 9-pin D-sub connector is changed to 6-pin RJ11
Triple tuner
Vu+ Ultimo (3 x pluggable DVB-S2 or DVB-T,T2/C tuners)
Vu+ Ultimo 4K (2 x pluggable FBC DVB-S/S2 tuner or dual FBC DVB-C tuner and 1 x p&p DVB-S2 or DVB-T/C tuners)
Twin tuner
Vu+ Duo 4K (2 x p&p slot for dual FBC DVB-S/S2X |
https://en.wikipedia.org/wiki/Radiative%20flux | Radiative flux, also known as radiative flux density or radiation flux (or sometimes power flux density), is the amount of power radiated through a given area, in the form of photons or other elementary particles, typically measured in W/m2. It is used in astronomy to determine the magnitude and spectral class of a star and in meteorology to determine the intensity of the convection in the planetary boundary layer. Radiative flux also acts as a generalization of heat flux, which is equal to the radiative flux when restricted to the infrared spectrum.
When radiative flux is incident on a surface, it is often called irradiance. Flux emitted from a surface may be called radiant exitance or radiant emittance. The ratio of irradiance reflected to the irradiance received by a surface is called albedo.
Shortwave radiation flux
Shortwave flux is a result of specular and diffuse reflection of incident shortwave radiation by the underlying surface. This shortwave radiation, as solar radiation, can have a profound impact on certain biophysical processes of vegetation, such as canopy photosynthesis and land surface energy budgets, by being absorbed into the soil and canopies. As it is the main energy source of most weather phenomena, the solar shortwave radiation is used extensively in numerical weather prediction.
Longwave radiation flux
Longwave flux is a product of both downwelling infrared energy as well as emission by the underlying surface. The cooling associated with the divergence of longwave radiation is necessary for creating and sustaining lasting inversion layers close to the surface during polar night. Longwave radiation flux divergence also plays a role in the formation of fog.
SI radiometry units
See also
Spectral flux density
Flux |
https://en.wikipedia.org/wiki/Halo%20mass%20function | In cosmology, the halo mass function is a mass distribution of dark matter halos. Specifically, it gives the number density of dark matter halos per mass interval. |
https://en.wikipedia.org/wiki/Translation%20functor | In mathematical representation theory, a (Zuckerman) translation functor is a functor taking representations of a Lie algebra to representations with a possibly different central character. Translation functors were introduced independently by and . Roughly speaking, the functor is given by taking a tensor product with a finite-dimensional representation, and then taking a subspace with some central character.
Definition
By the Harish-Chandra isomorphism, the characters of the center Z of the universal enveloping algebra of a complex reductive Lie algebra can be identified with the points of L⊗C/W, where L is the weight lattice and W is the Weyl group. If λ is a point of L⊗C/W then write χλ for the corresponding character of Z.
A representation of the Lie algebra is said to have central character χλ if every vector v is a generalized eigenvector of the center Z with eigenvalue χλ; in other words if z∈Z and v∈V then (z − χλ(z))n(v)=0 for some n.
The translation functor ψ takes representations V with central character χλ to representations with central character χμ. It is constructed in two steps:
First take the tensor product of V with an irreducible finite dimensional representation with extremal weight λ−μ (if one exists).
Then take the generalized eigenspace of this with eigenvalue χμ. |
https://en.wikipedia.org/wiki/Message%20queue | In computer science, message queues and mailboxes are software-engineering components typically used for inter-process communication (IPC), or for inter-thread communication within the same process. They use a queue for messaging – the passing of control or of content. Group communication systems provide similar kinds of functionality.
The message queue paradigm is a sibling of the publisher/subscriber pattern, and is typically one part of a larger message-oriented middleware system. Most messaging systems support both the publisher/subscriber and message queue models in their API, e.g. Java Message Service (JMS).
Remit and ownership
Message queues implement an asynchronous communication pattern between two or more processes/threads whereby the sending and receiving party do not need to interact with the message queue at the same time. Messages placed onto the queue are stored until the recipient retrieves them. Message queues have implicit or explicit limits on the size of data that may be transmitted in a single message and the number of messages that may remain outstanding on the queue.
Remit
Many implementations of message queues function internally within an operating system or within an application. Such queues exist for the purposes of that system only.
Other implementations allow the passing of messages between different computer systems, potentially connecting multiple applications and multiple operating systems. These message queuing systems typically provide resilience functionality to ensure that messages do not get "lost" in the event of a system failure. Examples of commercial implementations of this kind of message queuing software (also known as message-oriented middleware) include IBM MQ (formerly MQ Series) and Oracle Advanced Queuing (AQ). There is a Java standard called Java Message Service, which has several proprietary and free software implementations.
Real-time operating systems (RTOSes) such as VxWorks and QNX encourage the use of |
https://en.wikipedia.org/wiki/MacArabic%20encoding | MacArabic encoding is an obsolete encoding for Arabic (and English) text that was used in Apple Macintosh computers to texts.
The encoding is identical to MacFarsi encoding, except the numerals. |
https://en.wikipedia.org/wiki/Fishkeeping | Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture.
Origins of fishkeeping
Fish have been raised as food in pools and ponds for thousands of years. Brightly colored or tame specimens of fish in these pools have sometimes been valued as pets rather than food. Many cultures, ancient and modern, have kept fish for both functional and decorative purposes.
Ancient Sumerians kept wild-caught fish in ponds, before preparing them for meals. Depictions of the sacred fish of Oxyrhynchus kept in captivity in rectangular temple pools have been found in ancient Egyptian art.
Similarly, Asia has experienced a long history of stocking rice paddies with freshwater fish suitable for eating, including various types of catfish and cyprinid. Selective breeding of carp into today's popular and completely domesticated koi and fancy goldfish began over 2,000 years ago in Japan and China, respectively. The Chinese brought goldfish indoors during the Song Dynasty to enjoy them in large ceramic vessels.
In Medieval Europe, carp pools were a standard feature of estates and monasteries, providing an alternative to meat on feast days when meat could not be eaten for religious reasons.
Marine fish have been similarly valued for centuries. Wealthy Romans kept lampreys and other fish in salt water pools. Tertullian reports that Asinius Celer paid 8000 sesterces for a particularly fine mullet. Cicero reports that the advocate Quintus Hortensius wept when a favored specimen died. Rather cynically, he referred to these ancient fishkeepers as the Piscinarii, the "fish-pond owners" or "fish breeders", for example when saying that "the rich (I mean your friends the fish-breeders) did not disguise their jealousy of me".
The first person to breed a tropical fish in Europe was Pierre Carbonnier, who founded one of the oldest public aquaria in Par |
https://en.wikipedia.org/wiki/Operating%20System%20Projects | OSP, an Environment for Operating System Projects, is a teaching operating system designed to provide an environment for an introductory course in operating systems. By selectively omitting specific modules of the operating system and having the students re-implement the missing functionality, an instructor can generate projects that require students to understand fundamental operating system concepts.
The distribution includes the OSP project generator, which can be used to package a project and produce stubs (files that are empty except for required components, and that can be compiled) for the files that the students must implement. OSP includes a simulator that the student code runs on.
See also
Mobile operating system
Network operating system
Operating system |
https://en.wikipedia.org/wiki/Animal%20Drug%20Availability%20Act%201996 | The Animal Drug Availability Act 1996 (ADAA) is a United States federal law. President Clinton signed the ADAA into law in October 1996. While still obligated to public health concerns, the Act intends more rapid drug approval and medicated feed approval to assist the animal health industry.
Overview
The Animal Drug Availability Act specifies the conditions in which the U.S. Secretary of Health can refuse the application of a new drug. The possibility of an unconsidered hazard is not a permitted ground for refusing an application. The implications of the act include:
more relaxed controls on field studies unless requested and justified by the Center for Veterinary Medicine;
a strict demand for proof of efficacy;
a definition of adequate and well controlled procedures for field trials;
supporting labeling focused on the range of recommended or acceptable dosages;
the creation of Veterinary Feed Directive drugs as a new category of animal drugs.
Details
Antibiotics in agriculture before ADAA statute
Antibiotic use was once common practice before the ADAA approved the use of antibacterials in animal feed. For 1985 the estimated annual antibiotic use in the U.S. are as follows. Cows were given 1 million pounds of antibiotics, 0.55 million pounds for swine, and 0.67 million pounds for poultry as therapeutic use, constituting legitimate bacterial infection treatment. Quantities for subtherapeutic use specified as; increase the daily body weight gain, improve the food-to-weight gain ratio, and increase the voluntary intake of food equals 3.1 million pounds in cows, feeding swine with 11 million pounds, and poultry with 2 million pounds. For each of these livestock species the subtherapeutic use is substantially higher: this contributes unnecessarily to possible microbial resistance. Those quantities preceded the ADAA, so approving veterinary feed including antibiotics for market contributed to progressing livestock medication. In 2003 the over 24 million pounds |
https://en.wikipedia.org/wiki/GrassBase | GrassBase (or GrassBase – The Online World Grass Flora) is a web-based database of grasses, continually maintained and updated by the Royal Botanic Gardens, Kew.
As of 2015, GrassBase was one of the largest (along with GrassWorld) structured datasets for plants. In the January 2016 update, it had morphological descriptions for 11,369 accepted species of grasses and listings for 64,213 botanical names.
Authorship of the database is credited to W. D. Clayton, M. S. Vorontsova, K. T. Harman and H. Williamson. |
https://en.wikipedia.org/wiki/Motorific | Motorific is the brand name of a line of battery-operated slot car toys and related accessories marketed by the Ideal Toy Company from 1964 to the early 1970s. It differed from traditional slot car sets in that the cars were powered independently by a pair of AA batteries, rather than by an electrical connection to the track.
The cars ran on slotted plastic track which was snapped together in various layouts, ranging from a simple oval to elaborate patterns, some featuring jumps and hazards ("Motorific Torture Track"). Switches were available; they were designed so that a regardless of the direction from which a vehicle entered the switch, it could exit through either of the other two tracks, and so that as the vehicle passed through the switch, it would reverse the position of the switch, so that if it entered again through the same branch, without the position being manually changed, it would take the opposite path.
After removing and inverting the detachable slot-car pin, the cars could also be run on the floor, with the front wheels steerable into one of three set positions (left, center, right), held by small detents on the reverse side of the pin.
Although some playsets were marketed to feature competitive play between two operators ("Racerific"), in truth there was little allowance for competition since there was no operator control over speed.
Motorific vehicles and accessories remain popular as collectibles, particularly with baby boomer toy aficionados.
Marketing
Ideal introduced the Motorific line in 1964 as "The New Quick-Change Motor Toy", offering a variety of popular car body styles that were interchangeable with common snap-on chassis and electric motors. Each of the three elements were sold separately and as sets in various combinations, as well as being packaged with a variety of track layouts.
The interchangeable bodies rode on a plastic chassis, with a removable "CU-24" motor. It was powered by two AA batteries which mounted in the chassi |
https://en.wikipedia.org/wiki/IEEEmadC | IEEEmadC (Mobile Applications Development Contest) is an international contest organized by volunteers for IEEE student members across the globe. The main goal is to educate and encourage students to pursue their future career as mobile application developers, develop their engineering, social and team skills and consequently become more competitive in the labor market. The contest is organized online with three phases: Education and Idea, Development and Judging stage. Teams up to three IEEE student members are invited to devise and develop mobile applications. Develop a mobile app and win big prizes SIX criteria will be judged: UI Design, User Experience, Usefulness, Availability, Number of supported platforms and Open source support.
History
IEEEmadC started in the fall of 2013 from University of J.J.Strossmayer Student Branch in Osijek, Croatia. Contest was founded by Josip Balen, Luka Horvat and Igor Bedek with support from IEEE R8 Student Activities Committee. The first iteration of the contest was for IEEE students in Europe, Africa and the Middle East (Region 8). The second iteration of the contest was organized worldwide for IEEE student members in all 10 IEEE regions. IEEEmadC is enjoying its 3rd year of competition in 2016.
Received honours
Contest stages
Education stage
The main goals of the Educational stage are to educate and encourage students to become MAD (Mobile Application Developers), develop their engineering, social and team skills and consequently become more competitive in the labor market. During this stage IEEEmadC ambassadors with experts from industry organize webinars on mobile application development. Furthermore, with help from university professors they are organizing technical workshops and lectures in their local IEEE sections, universities and IEEE student branches around the globe.
Idea stage
In this stage students are able to register by submitting their ideas about mobile applications that they would like to develop. All |
https://en.wikipedia.org/wiki/Pair%20bond | In biology, a pair bond is the strong affinity that develops in some species between a mating pair, often leading to the production and rearing of offspring and potentially a lifelong bond. Pair-bonding is a term coined in the 1940s that is frequently used in sociobiology and evolutionary biology circles. The term often implies either a lifelong socially monogamous relationship or a stage of mating interaction in socially monogamous species. It is sometimes used in reference to human relationships.
Varieties
According to evolutionary psychologists David P. Barash and Judith Lipton, from their 2001 book The Myth of Monogamy, there are several varieties of pair bonds:
Short-term pair-bond: a transient mating or associations
Long-term pair-bond: bonded for a significant portion of the life cycle of that pair
Lifelong pair-bond: mated for life
Social pair-bond: attachments for territorial or social reasons
Clandestine pair-bond: quick extra-pair copulations
Dynamic pair-bond: e.g. gibbon mating systems being analogous to "divorce"
Human pair bonding
Humans can experience all of the above-mentioned varieties of pair bonds. These bonds can be temporary or last a lifetime. Pair bonding is a behavioral and physiological bond between two mated individuals, and is rare among non-human primates. Humans also engage in social pair bonding, where two individuals will form a close relationship that does not involve sex. In humans and other vertebrates, pair bonds are created by a combination of social interaction and biological factors including neurotransmitters like oxytocin, vasopressin, and dopamine.
Pair bonds are a biological phenomenon and are not equivalent to the human social institution of marriage. Married couples are not necessarily pair bonded. Marriage may be a consequence of pair bonding and vice versa. One of the functions of romantic love is pair bonding.
Examples
Birds
Close to ninety percent of known avian species are monogamous, compared to five percent |
https://en.wikipedia.org/wiki/G%C3%B6del%27s%20%CE%B2%20function | In mathematical logic, Gödel's β function is a function used to permit quantification over finite sequences of natural numbers in formal theories of arithmetic. The β function is used, in particular, in showing that the class of arithmetically definable functions is closed under primitive recursion, and therefore includes all primitive recursive functions.
The β function was introduced without the name in the proof of the first of Gödel's incompleteness theorems (Gödel 1931). The β function lemma given below is an essential step of that proof. Gödel gave the β function its name in (Gödel 1934).
Definition
The function takes three natural numbers as arguments. It is defined as
where denotes the remainder after integer division of by (Mendelson 1997:186).
Properties
The β function is arithmetically definable in an obvious way, because it uses only arithmetic operations and the remainder function which is arithmetically definable. It is therefore representable in Robinson arithmetic and stronger theories such as Peano arithmetic. By fixing the first two arguments appropriately, one can arrange that the values obtained by varying the final argument from 0 to n run through any specified (n+1)-tuple of natural numbers (the β lemma described in detail below). This allows simulating the quantification over sequences of natural numbers of arbitrary length, which cannot be done directly in the language of arithmetic, by quantification over just two numbers, to be used as the first two arguments of the β function.
For example, if f is a function defined by primitive recursion on a parameter n, say by f(0) = c and f(n+1) = g(n, f(n)), then to express f(n) = y one would like to say: there exists a sequence a0, a1, …, an such that a0 = c, an = y and for all i < n one has g(i, ai) = ai+1. While that is not possible directly, one can say instead: there exist natural numbers a and b such that β(a,b,0) = c, β(a,b,n) = y and for all i < n one has g(i, β(a,b,i)) = β(a |
https://en.wikipedia.org/wiki/Hydration%20%28web%20development%29 | In web development, hydration or rehydration is a technique in which client-side JavaScript converts a static HTML web page, delivered either through static hosting or server-side rendering, into a dynamic web page by attaching event handlers to the HTML elements. Because the HTML is pre-rendered on a server, this allows for a fast "first contentful paint" (when useful data is first displayed to the user), but there is a period of time afterward where the page appears to be fully loaded and interactive, but is not until the client-side JavaScript is executed and event handlers have been attached.
Frameworks that use hydration include Next.js and Nuxt.js. React v16.0 introduced a "hydrate" function, which hydrates an element, in its API.
Variations
Streaming server-side rendering
Streaming server-side rendering allows one to send HTML in chunks that the browser can progressively render as it is received. This can provide a fast first paint and first contentful paint as HTML markup arrives to users faster.
Progressive rehydration
In progressive rehydration, individual pieces of a server-rendered application are “booted up” over time, rather than the current common approach of initializing the entire application at once. This can help reduce the amount of JavaScript required to make pages interactive, since client-side upgrading of low priority parts of the page can be deferred to prevent blocking the main thread. It can also help avoid one of the most common server-side rendering rehydration pitfalls, where a server-rendered DOM tree gets destroyed and then immediately rebuilt – most often because the initial synchronous client-side render required data that wasn't quite ready, perhaps awaiting Promise resolution.
Partial rehydration
Partial rehydration has proven difficult to implement. This approach is an extension of the idea of progressive rehydration, where the individual pieces (components/views/trees) to be progressively rehydrated are analyzed and thos |
https://en.wikipedia.org/wiki/Kawamata%E2%80%93Viehweg%20vanishing%20theorem | In algebraic geometry, the Kawamata–Viehweg vanishing theorem is an extension of the Kodaira vanishing theorem, on the vanishing of coherent cohomology groups, to logarithmic pairs, proved independently by Viehweg and Kawamata in 1982.
The theorem states that if L is a big nef line bundle (for example, an ample line bundle) on a complex projective manifold with canonical line bundle K,
then the coherent cohomology groups Hi(L⊗K) vanish for all positive i. |
https://en.wikipedia.org/wiki/Gaze%20%28physiology%29 | The term gaze is frequently used in physiology to describe coordinated motion of the eyes and neck. The lateral gaze is controlled by the paramedian pontine reticular formation (PPRF). The vertical gaze is controlled by the rostral interstitial nucleus of medial longitudinal fasciculus and the interstitial nucleus of Cajal.
Nerves and muscles
The three nerves that control the extraocular muscles are the oculomotor, trochlear, and abducens nerves, which are the third, fourth, and sixth cranial nerves. the abducens nerve is responsible for abducting the eye, which it controls through contraction of the lateral rectus muscle. The trochlear nerve controls the superior oblique muscle to rotate the eye along its axis in the orbit medially, which is called intorsion, and is a component of focusing the eyes on an object close to the face. The oculomotor nerve controls all the other extraocular muscles, as well as a muscle of the upper eyelid.
Conjugate gaze
The conjugate gaze is the motion of both eyes in the same direction at the same time, and conjugate gaze palsy refers to an impairment of this function. The conjugate gaze is controlled by four different mechanisms:
the saccadic system that allows for voluntary direction of the gaze
the pursuit system that allows the subject to follow a moving object
nystagmus which includes both vestibular nystagmus and optokinetic nystagmus. The vestibular system restores gaze in compensation for the rotation of the head whereas the optokinetic system restores gaze despite movements of the outside world.
the vestibulo-ocular reflex system (VOR system) that corrects for the movements of the head to preserve the stable visual image of the world |
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