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https://en.wikipedia.org/wiki/International%20Conference%20on%20Dependable%20Systems%20and%20Networks
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The International Conference on Dependable Systems and Networks (or DSN) is an annual conference on topics related to dependable computer systems and reliable networks. It typically features a number of coordinated tracks, including the main paper track, several workshops, tutorials, industry session, a student forum, and fast abstracts. It is sponsored by the IEEE and the IFIP WG 10.4 on Dependable Computing and Fault Tolerance. DSN was formed in 2000 by merging the IEEE International Symposium on Fault-Tolerant Computing (FTCS) and the IFIP International Working Conference on Dependable Computing for Critical Applications (DCCA). The instance number for DSN is taken from FTCS which was first held in 1980 and annually thereafter.
A DSN Hall of Fame ranks the researchers by the number of papers that they have published in DSN.
In 2020, the 50th DSN was to be held in Valencia, Spain and due to the Covid situation, was held virtually.
In 2021, the 51st DSN was to be held in Taipei, Taiwan and due to the Covid situation, was held virtually.
In 2022, the 52nd DSN was held in person in Baltimore, Maryland, United States.
In 2023, the 53rd DSN is scheduled to be held in Porto, Portugal.
Awards
The following awards are given at DSN.
Best paper award: The winner from among three nominees is selected through audience voting
William C. Carter PhD Dissertation Award in Dependability
Rising Star in Dependability Award
Test-of-Time Award: This recognizes two papers published at DSN 10 years ago
Jean-Claude Laprie Award: This recognizes outstanding papers that have significantly influenced the theory and/or practice of dependable computing
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https://en.wikipedia.org/wiki/Fader%20creep
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Fader creep is a colloquial term used in audio recording to describe a tendency for sound engineers to raise the gain of individual channels on a mixing console, rather than lowering others to achieve the desired change in the mix.
Results of creeping
As a result, the faders (potentiometers that operate by sliding up or down) or volume controls (rotary potentiometers) on the mixing board or audio processor gradually "creep" toward the maximum volume setting, which reduces the ability to manipulate the relative volumes between channels. It can also result in clipping or distortion of the master mix, which is when the overall volume of sound is too great for the equipment or recording medium intended to hold it.
Multi track problems with creep
Fader creep can be a particular problem in audio mixing sessions for multi-track recordings, where individual sounds held on separate audio tracks, or delivered by outboard MIDI or computer audio equipment are combined into the final stereo presentation of the recording. For example, an engineer might compensate for a particularly loud drum track by raising the volumes of the voice, the guitar, and the piano to the point where all of the individual signals are competing for headroom. A better solution is to lower the volume of the drums, and adjust the other channels accordingly.
Live concert creep
In audio mixing for live concerts, fader creep can result when ear fatigue (the diminishing of the ability for the human ear to hear clearly after prolonged exposure to loud sounds) reduces the ability of the sound engineer to hear the individual components of the mix (i.e. separate instruments and voices on the stage) accurately.
Audio mixing
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https://en.wikipedia.org/wiki/Hydroperoxide
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Hydroperoxides or peroxols are compounds of the form ROOH, which contain the hydroperoxy functional group (–OOH). The hydroperoxide anion () and the neutral hydroperoxyl radical (HOO·) consist of an unbond hydroperoxy group. When R is organic, the compounds are called organic hydroperoxides. Such compounds are a subset of organic peroxides, which have the formula ROOR. Organic hydroperoxides can either intentionally or unintentionally initiate explosive polymerisation in materials with unsaturated chemical bonds.
Properties
The O−O bond length in peroxides is about 1.45 Å, and the R−O−O angles (R = H, C) are about 110° (water-like). Characteristically, the C−O−O−H dihedral angles are about 120°. The O−O bond is relatively weak, with a bond dissociation energy of , less than half the strengths of C−C, C−H, and C−O bonds.
Hydroperoxides are typically more volatile than the corresponding alcohols:
tert-BuOOH (b.p. 36°C) vs tert-BuOH (b.p. 82-83°C)
CH3OOH (b.p. 46°C) vs CH3OH (b.p. 65°C)
cumene hydroperoxide (b.p. 153°C) vs cumyl alcohol (b.p. 202°C)
Miscellaneous reactions
Hydroperoxides are mildly acidic. The range is indicated by 11.5 for CH3OOH to 13.1 for Ph3COOH.
Hydroperoxides can be reduced to alcohols with lithium aluminium hydride, as described in this idealized equation:
4 ROOH + LiAlH4 → LiAlO2 + 2 H2O + 4 ROH
This reaction is the basis of methods for analysis of organic peroxides. Another way to evaluate the content of peracids and peroxides is the volumetric titration with alkoxides such as sodium ethoxide.
The phosphite esters and tertiary phosphines also effect reduction:
ROOH + PR3 → OPR3 + ROH
Uses
Precursors to epoxides
"The single most important synthetic application of alkyl hydroperoxides is without doubt the metal-catalysed epoxidation of alkenes." In the Halcon process tert-butyl hydroperoxide (TBHP) is employed for the production of propylene oxide.
Of specialized interest, chiral epoxides are prepared using hydropero
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https://en.wikipedia.org/wiki/Pneumatic%20gripper
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A pneumatic gripper is a specific type of pneumatic actuator that typically involves either parallel or angular motion of surfaces, A.K.A. “tooling jaws or fingers” that will grip an object. The gripper makes use of compressed air which powers a piston rod inside the tool. Grippers exist both internal with and external bore grip with the same equipment because of an increased quantity of cross rollers in the parallel slide part.
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https://en.wikipedia.org/wiki/Paint%20by%20number
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Paint by number or painting by numbers kits are self-contained painting sets, designed to facilitate painting a pre-designed image. They generally include brushes, tubs of paint with numbered labels, and a canvas printed with borders and numbers. The user selects the color corresponding to one of the numbers then uses it to fill in a delineated section of the canvas, in a manner similar to a coloring book.
The kits were invented, developed and marketed in 1950 by Max S. Klein, an engineer and owner of the Palmer Paint Company in Detroit, Michigan, and Dan Robbins, a commercial artist. When Palmer Paint introduced crayons to consumers, they also posted images online for a "Crayon by Number" version.
History
The first patent for the paint by number technique was filed in 1923.
Paint by Number in its popular form was created by the Palmer Show Card Paint Company. The owner of the company approached employee Dan Robbins with the idea for the project. After several iterations of the product, the company in 1951 introduced the Craft Master brand, which went on to sell over 12 million kits. This public response induced other companies to produce their own versions of paint by number. The Craft Master paint kit box tops proclaimed, "A BEAUTIFUL OIL PAINTING THE FIRST TIME YOU TRY."
Following the death of Max Klein in 1993, his daughter, Jacquelyn Schiffman, donated the Palmer Paint Co. archives to the Smithsonian Museum of American History. The archival materials have been placed in the museum's Archives Center where they have been designated collection #544, the "Paint by Number Collection".
In 1992, Michael O'Donoghue and Trey Speegle organized and mounted a show of O'Donoghue's paint by number collection in New York City at the Bridgewater/Lustberg Gallery. After O'Donoghue's death in 1994, the Smithsonian Institution's National Museum of American History exhibited many key pieces from O'Donoghue's collection, now owned by Speegle, along with works from other col
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https://en.wikipedia.org/wiki/Dreamwork
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Dreamwork differs from classical dream interpretation in that the aim is to explore the various images and emotions that a dream presents and evokes, while not attempting to come up with a unique dream meaning. In this way the dream remains "alive" whereas if it has been assigned a specific meaning, it is "finished" (i.e., over and done with). Dreamworkers take the position that a dream may have a variety of meanings depending on the levels (e.g. subjective, objective) that are being explored.
A belief of dreamwork is that each person has their own dream "language". Any given place, person, object, or symbol can differ in its meaning from dreamer to dreamer and also from time to time in the dreamer's ongoing life situation. Thus someone helping a dreamer get closer to their dream through dreamwork adopts an attitude of "not knowing" as far as possible.
In dreamwork it is usual to wait until all the questions have been asked—and the answers carefully listened to—before the dreamworker (or dreamworkers if it is done in a group setting) offers any suggestions about what the dream might mean. In fact, a dreamworker often prefaces any interpretation by saying, "if this were my dream, it might mean..." (a technique first developed by Montague Ullman, Stanley Krippner, and Jeremy Taylor and now widely practiced). In this way, dreamers are not obliged to agree with what is said and may use their own judgment in deciding which comments appear valid or provide insight. If the dreamwork is done in a group, there may well be several things that are said by participants that seem valid to the dreamer but it can also happen that nothing does. Appreciation of the validity or insightfulness of a comment from a dreamwork session can come later, sometimes days after the end of the session.
Dreamwork or dream-work can also refer to Sigmund Freud's idea that a person's forbidden and repressed desires are distorted in dreams, so they appear in disguised forms. Freud used the term 'dr
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https://en.wikipedia.org/wiki/Minimundus
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Minimundus is a miniature park in Klagenfurt in Carinthia, Austria. It displays over 150 miniature models of architecture from around the world, built at a ratio of 1:25.
History
Since its opening in 1958, more than 15 million visitors have visited the 26,000 square meters park. The proceeds benefit the children's help organization Rettet das Kind ("Save the Child"), which owns the park.
Models
A small selection of the models:
St. Stephen's Cathedral
Statue of Liberty
Saint Peter's Basilica
Cathedral of Brasília
Toronto CN Tower
Eiffel Tower
Hochosterwitz Castle in Austria
Sydney Opera House
Tower of London
White House
Taj Mahal
Baiturrahman Grand Mosque
Castillo de Coca
Atomium
Many trains of Europe
The Space Shuttle and its launch pad
Most of the models are transportable and are moved to other areas during off-season winter.
See also
Madurodam
Mini-Europe
Window of the World
Gallery
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https://en.wikipedia.org/wiki/Miniature%20park
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A miniature park is a display of miniature buildings and models, usually as a recreational and tourist attraction open to the public. A miniature park may contain a model of a single city or town, often called a miniature city or model village, or it can contain a number of different sets of models.
History
There is evidence to suggest the existence of private model villages and miniature parks since the 19th century, but it was only in the 1930s to 1950s that the genre became tourist attractions. Early examples include Bekonscot in the UK and Madurodam in The Hague.
Variations on a theme
Most model villages and parks are built to a consistent scale; varying from 1:76 as used by the intricately detailed Pendon in England up to the 1:9 scale of Wimborne Model Town.
There has been a move away from the model village concept since the mid- to late 20th century towards a miniature park concept. Model villages are typically larger-scale, sit in a cohesive miniature landscape and allow viewing and physical interaction with the exhibits, such as publicly accessed streets and urban areas. Miniature parks however, are primarily concerned with the display of exhibits in their own right, viewed from a distance. Model railways, rivers and roads may provide a continuation between miniature parks exhibits.
List of notable miniature parks
Europe
Austria
Minimundus, Klagenfurt
Belgium
Mini-Europe, Brussels
Denmark
Legoland Billund, Billund (the original Legoland)
Many Danish towns also have extensive miniature towns from historic periods (normally 1900s). Some of the most significant include:
, Fredericia (circa 1849)
, Køge (circa 1865)
, Varde (circa 1866)
, Kolding (circa 1860-1870)
France
France Miniature, Élancourt
Mini World Lyon
Storybook Land Canal Boats, Disneyland Park (Paris)
Germany
Legoland Deutschland, Günzburg, Bavaria
Miniatur Wunderland, Hamburg (indoor)
Italy
Italia in miniatura, Rimini
Netherlands
Madurodam, The Hague
Portugal
Portugal
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https://en.wikipedia.org/wiki/Unix%20architecture
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A Unix architecture is a computer operating system system architecture that embodies the Unix philosophy. It may adhere to standards such as the Single UNIX Specification (SUS) or similar POSIX IEEE standard. No single published standard describes all Unix architecture computer operating systems — this is in part a legacy of the Unix wars.
Description
There are many systems which are Unix-like in their architecture. Notable among these are the Linux distributions. The distinctions between Unix and Unix-like systems have been the subject of heated legal battles, and the holders of the UNIX brand, The Open Group, object to "Unix-like" and similar terms.
For distinctions between SUS branded UNIX architectures and other similar architectures, see Unix-like.
Kernel
A Unix kernel — the core or key components of the operating system — consists of many kernel subsystems like process management, scheduling, file management, device management, network management, memory management, and dealing with interrupts from hardware devices.
Each of the subsystems has some features:
Concurrency: As Unix is a multiprocessing OS, many processes run concurrently to improve the performance of the system.
Virtual memory (VM): Memory management subsystem implements the virtual memory concept and users need not worry about the executable program size and the RAM size.
Paging: It is a technique to minimize the internal as well as the external fragmentation in the physical memory.
Virtual file system (VFS): A VFS is a file system used to help the user to hide the different file systems complexities. A user can use the same standard file system related calls to access different file systems.
The kernel provides these and other basic services: interrupt and trap handling, separation between user and system space, system calls, scheduling, timer and clock handling, file descriptor management.
Features
Some key features of the Unix architecture concept are:
Unix systems use a central
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https://en.wikipedia.org/wiki/Sample-rate%20conversion
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Sample-rate conversion, sampling-frequency conversion or resampling is the process of changing the sampling rate or sampling frequency of a discrete signal to obtain a new discrete representation of the underlying continuous signal. Application areas include image scaling and audio/visual systems, where different sampling rates may be used for engineering, economic, or historical reasons.
For example, Compact Disc Digital Audio and Digital Audio Tape systems use different sampling rates, and American television, European television, and movies all use different frame rates. Sample-rate conversion prevents changes in speed and pitch that would otherwise occur when transferring recorded material between such systems.
More specific types of resampling include: upsampling or upscaling; downsampling, downscaling, or decimation; and interpolation.
The term multi-rate digital signal processing is sometimes used to refer to systems that incorporate sample-rate conversion.
Techniques
Conceptual approaches to sample-rate conversion include: converting to an analog continuous signal, then re-sampling at the new rate, or calculating the values of the new samples directly from the old samples. The latter approach is more satisfactory since it introduces less noise and distortion. Two possible implementation methods are as follows:
If the ratio of the two sample rates is (or can be approximated by) a fixed rational number L/M: generate an intermediate signal by inserting L − 1 zeros between each of the original samples. Low-pass filter this signal at half of the lower of the two rates. Select every M-th sample from the filtered output, to obtain the result.
Treat the samples as geometric points and create any needed new points by interpolation. Choosing an interpolation method is a trade-off between implementation complexity and conversion quality (according to application requirements). Commonly used are: ZOH (for film/video frames), cubic (for image processing) and w
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https://en.wikipedia.org/wiki/Callan%E2%80%93Symanzik%20equation
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In physics, the Callan–Symanzik equation is a differential equation describing the evolution of the n-point correlation functions under variation of the energy scale at which the theory is defined and involves the beta function of the theory and the anomalous dimensions.
As an example, for a quantum field theory with one massless scalar field and one self-coupling term, denote the bare field strength by and the bare coupling constant by . In the process of renormalisation, a mass scale M must be chosen. Depending on M, the field strength is rescaled by a constant: , and as a result the bare coupling constant is correspondingly shifted to the renormalised coupling constant g.
Of physical importance are the renormalised n-point functions, computed from connected Feynman diagrams, schematically of the form
For a given choice of renormalisation scheme, the computation of this quantity depends on the choice of M, which affects the shift in g and the rescaling of . If the choice of is slightly altered by , then the following shifts will occur:
The Callan–Symanzik equation relates these shifts:
After the following definitions
the Callan–Symanzik equation can be put in the conventional form:
being the beta function.
In quantum electrodynamics this equation takes the form
where n and m are the numbers of electron and photon fields, respectively, for which the correlation function is defined. The renormalised coupling constant is now the renormalised elementary charge e. The electron field and the photon field rescale differently under renormalisation, and thus lead to two separate functions, and , respectively.
The Callan–Symanzik equation was discovered independently by Curtis Callan and Kurt Symanzik in 1970. Later it was used to understand asymptotic freedom.
This equation arises in the framework of renormalization group. It is possible to treat the equation using perturbation theory.
See also
Exact renormalization group equation
Beta function
Notes
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https://en.wikipedia.org/wiki/Conformal%20gravity
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Conformal gravity refers to gravity theories that are invariant under conformal transformations in the Riemannian geometry sense; more accurately, they are invariant under Weyl transformations where is the metric tensor and is a function on spacetime.
Weyl-squared theories
The simplest theory in this category has the square of the Weyl tensor as the Lagrangian
where is the Weyl tensor. This is to be contrasted with the usual Einstein–Hilbert action where the Lagrangian is just the Ricci scalar. The equation of motion upon varying the metric is called the Bach tensor,
where is the Ricci tensor. Conformally flat metrics are solutions of this equation.
Since these theories lead to fourth-order equations for the fluctuations around a fixed background, they are not manifestly unitary. It has therefore been generally believed that they could not be consistently quantized. This is now disputed.
Four-derivative theories
Conformal gravity is an example of a 4-derivative theory. This means that each term in the wave equation can contain up to four derivatives. There are pros and cons of 4-derivative theories. The pros are that the quantized version of the theory is more convergent and renormalisable. The cons are that there may be issues with causality. A simpler example of a 4-derivative wave equation is the scalar 4-derivative wave equation:
The solution for this in a central field of force is:
The first two terms are the same as a normal wave equation. Because this equation is a simpler approximation to conformal gravity, m corresponds to the mass of the central source. The last two terms are unique to 4-derivative wave equations. It has been suggested that small values be assigned to them to account for the galactic acceleration constant (also known as dark matter) and the dark energy constant. The solution equivalent to the Schwarzschild solution in general relativity for a spherical source for conformal gravity has a metric with:
to show the difference betw
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https://en.wikipedia.org/wiki/Microvasculature%20remodeling
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Microvasculature remodeling refers to the alterations in a blood vessel network resulting from arteriogenesis and angiogenesis. Briefly, arteriogenesis is an increase in arterial diameter while angiogenesis is an increase in the number of capillaries either by sprouting from or splitting existing capillaries. External events stimulate these two types of vessel growth through a combination of mechanical and chemical pathways (Prior et al., 2004).
Sources
Prior, B. M., Yang, H. T., & Terjung, R. L. What makes vessels grow with exercise training? J App Physiol 97: 1119–28, 2004.
Angiology
Cardiac electrophysiology
Cardiovascular physiology
Cardiovascular procedures
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https://en.wikipedia.org/wiki/Sgoldstino
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A sgoldstino is any of the spin-0 superpartners of the goldstino in relativistic quantum field theories with spontaneously broken supersymmetry. The term sgoldstino was first used in 1998.
In 2016, Petersson and Torre hypothesized that a sgoldstino particle might be responsible for the observed 750 GeV diphoton excess observed by Large Hadron Collider experiments.
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https://en.wikipedia.org/wiki/Conformally%20flat%20manifold
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A (pseudo-)Riemannian manifold is conformally flat if each point has a neighborhood that can be mapped to flat space by a conformal transformation.
In practice, the metric of the manifold has to be conformal to the flat metric , i.e., the geodesics maintain in all points of the angles by moving from one to the other, as well as keeping the null geodesics unchanged, that means exists a function such that , where is known as the conformal factor and is a point on the manifold.
More formally, let be a pseudo-Riemannian manifold. Then is conformally flat if for each point in , there exists a neighborhood of and a smooth function defined on such that is flat (i.e. the curvature of vanishes on ). The function need not be defined on all of .
Some authors use the definition of locally conformally flat when referred to just some point on and reserve the definition of conformally flat for the case in which the relation is valid for all on .
Examples
Every manifold with constant sectional curvature is conformally flat.
Every 2-dimensional pseudo-Riemannian manifold is conformally flat.
The line element of the two dimensional spherical coordinates, like the one used in the geographic coordinate system,
, has metric tensor and is not flat but with the stereographic projection can be mapped to a flat space using the conformal factor , where is the distance from the origin of the flat space, obtaining
.
A 3-dimensional pseudo-Riemannian manifold is conformally flat if and only if the Cotton tensor vanishes.
An n-dimensional pseudo-Riemannian manifold for n ≥ 4 is conformally flat if and only if the Weyl tensor vanishes.
Every compact, simply connected, conformally Euclidean Riemannian manifold is conformally equivalent to the round sphere.
The stereographic projection provides a coordinate system for the sphere in which conformal flatness is explicit, as the metric is proportional to the flat one.
In general relativity conformally flat manifolds can oft
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https://en.wikipedia.org/wiki/Singleton%20field
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A singleton field theory is a quantum field theory that treats massless particles in anti-de Sitter spacetime as pairs of "singletons". Originally introduced by Moshé Flato and Christian Frønsdal, they are based on Paul Dirac's work on the representation theory of the group SO(3,2).
See also
Preon
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https://en.wikipedia.org/wiki/Cortical%20reaction
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The cortical reaction is a process initiated during fertilization that prevents polyspermy, the fusion of multiple sperm with one egg. In contrast to the fast block of polyspermy which immediately but temporarily blocks additional sperm from fertilizing the egg, the cortical reaction gradually establishes a permanent barrier to sperm entry and functions as the main part of the slow block of polyspermy in many animals.
To create this barrier, cortical granules, specialized secretory vesicles located within the egg's cortex (the region directly below the plasma membrane), are fused with the egg's plasma membrane. This releases the contents of the cortical granules outside the cell, where they modify an existing extracellular matrix to make it impenetrable to sperm entry. The cortical granules contain proteases that clip perivitelline tether proteins, peroxidases that harden the vitelline envelope, and glycosaminoglycans that attract water into the perivitelline space, causing it to expand and form the hyaline layer. The trigger for the cortical granules to exocytose is the release of calcium ions from cortical smooth endoplasmic reticulum in response to sperm binding to the egg.
In most animals, the extracellular matrix present around the egg is the vitelline envelope which becomes the fertilization membrane following the cortical reaction. In mammals, however, the extracellular matrix modified by the cortical reaction is the zona pellucida. This modification of the zona pellucida is known as the zona reaction. Although highly conserved across the animal kingdom, the cortical reaction shows great diversity between species. While much has been learned about the identity and function of the contents of the cortical granules in the highly accessible sea urchin, little is known about the contents of cortical granules in mammals.
The cortical reaction within the egg is analogous to the acrosomal reaction within the sperm, where the acrosome, a specialized secretory ves
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https://en.wikipedia.org/wiki/Doctest
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doctest is a module included in the Python programming language's standard library that allows the easy generation of tests based on output from the standard Python interpreter shell, cut and pasted into docstrings.
Implementation specifics
Doctest makes innovative use of the following Python capabilities:
docstrings
The Python interactive shell (both command line and the included idle application)
Python introspection
When using the Python shell, the primary prompt: >>> , is followed by new commands. The secondary prompt: ... , is used when continuing commands on multiple lines; and the result of executing the command is expected on following lines.
A blank line, or another line starting with the primary prompt is seen as the end of the output from the command.
The doctest module looks for such sequences of prompts in a docstring, re-executes the extracted command and checks the output against the output of the command given in the docstrings test example.
The default action when running doctests is for no output to be shown when tests pass. This can be modified by options to the doctest runner. In addition, doctest has been integrated with the Python unit test module allowing doctests to be run as standard unittest testcases. Unittest testcase runners allow more options when running tests such as the reporting of test statistics such as tests passed, and failed.
Literate programming and doctests
Although doctest does not allow a Python program to be embedded in narrative text, it does allow for verifiable examples to be embedded in docstrings, where the docstrings can contain other text. Docstrings can in turn be extracted from program files to generate documentation in other formats such as HTML or PDF.
A program file can be made to contain the documentation, tests, as well as the code and the tests easily verified against the code. This allows code, tests, and documentation to evolve together.
Documenting libraries by example
Doctests are well suite
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https://en.wikipedia.org/wiki/Affine%20hull
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In mathematics, the affine hull or affine span of a set S in Euclidean space Rn is the smallest affine set containing S, or equivalently, the intersection of all affine sets containing S. Here, an affine set may be defined as the translation of a vector subspace.
The affine hull aff(S) of S is the set of all affine combinations of elements of S, that is,
Examples
The affine hull of the empty set is the empty set.
The affine hull of a singleton (a set made of one single element) is the singleton itself.
The affine hull of a set of two different points is the line through them.
The affine hull of a set of three points not on one line is the plane going through them.
The affine hull of a set of four points not in a plane in R3 is the entire space R3.
Properties
For any subsets
is a closed set if is finite dimensional.
If then .
If then is a linear subspace of .
.
So in particular, is always a vector subspace of .
If is convex then
For every , where is the smallest cone containing (here, a set is a cone if for all and all non-negative ).
Hence is always a linear subspace of parallel to .
Related sets
If instead of an affine combination one uses a convex combination, that is one requires in the formula above that all be non-negative, one obtains the convex hull of S, which cannot be larger than the affine hull of S as more restrictions are involved.
The notion of conical combination gives rise to the notion of the conical hull
If however one puts no restrictions at all on the numbers , instead of an affine combination one has a linear combination, and the resulting set is the linear span of S, which contains the affine hull of S.
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https://en.wikipedia.org/wiki/Core-based%20trees
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Core-based trees (CBT) is a proposal for making IP Multicast scalable by constructing a tree of routers. It was first proposed in a paper by Ballardie, Francis, and Crowcroft. What differentiates it from other schemes for multicasting is that the routing tree comprises multiple "cores" (also known as "centres"). The locations of the core routers are statically configured. Other routers are added by growing "branches" of a tree, comprising a chain of routers, from the core routers out towards the routers directly adjacent to the multicast group members.
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https://en.wikipedia.org/wiki/Acanthus%20%28ornament%29
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The acanthus () is one of the most common plant forms to make foliage ornament and decoration in the architectural tradition emanating from Greece and Rome.
Architecture
In architecture, an ornament may be carved into stone or wood to resemble leaves from the Mediterranean species of the Acanthus genus of plants, which have deeply cut leaves with some similarity to those of the thistle and poppy. Both Acanthus mollis and the still more deeply cut Acanthus spinosus have been claimed as the main model, and particular examples of the motif may be closer in form to one or the other species; the leaves of both are, in any case, rather variable in form. The motif is found in decoration in nearly every medium.
The relationship between acanthus ornament and the acanthus plant has been the subject of a long-standing controversy. Alois Riegl argued in his Stilfragen that acanthus ornament originated as a sculptural version of the palmette, and only later began to resemble Acanthus spinosus.
Greek and Roman
In ancient Roman and ancient Greek architecture acanthus ornament appears extensively in the capitals of the Corinthian and Composite orders, and applied to friezes, dentils and other decorated areas. The oldest known example of a Corinthian column is in the Temple of Apollo Epicurius at Bassae in Arcadia, c. 450–420 BC, but the order was used sparingly in Greece before the Roman period. The Romans elaborated the order with the ends of the leaves curled, and it was their favourite order for grand buildings, with their own invention of the Composite, which was first seen in the epoch of Augustus. Acanthus decoration continued in popularity in Byzantine, Romanesque, and Gothic architecture. It saw a major revival in the Renaissance, and still is used today.
The Roman writer Vitruvius (c. 75 – c. 15 BC) related that the Corinthian order had been invented by Callimachus, a Greek architect and sculptor who was inspired by the sight of a votive basket that had been left on t
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https://en.wikipedia.org/wiki/Medical%20advice
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Medical advice is the provision of a formal professional opinion regarding what a specific individual should or should not do to restore or preserve health. Typically, medical advice involves giving a diagnosis and/or prescribing a treatment for medical condition.
Medical advice can be distinguished from medical information, which is the relation of facts. Discussing facts and information is considered a fundamental free speech right and is not considered medical advice. Medical advice can also be distinguished from personal advice, even if the advice concerns medical care.
Doctor–patient relationship
Medical advice is given in the context of a doctor–patient relationship. A licensed health care professional can be held legally liable for the advice he or she gives to a patient. Giving bad advice may be considered medical malpractice under specified circumstances.
The doctor–patient relationship is one factor in determining the patient's compliance with medical advice. Patients adhere more closely to medical advice when the healthcare provider is friendly, doesn't interrupt the patient, or has good verbal communication skills. Patients are less likely to comply with medical advice if the advice is not what the patients expected, if the patients do not agree with the proposed treatment, if the patient is not confident in the provider's competence, or if the patient cannot understand what the provider says due to language barriers or overuse of medical jargon. Patients are also less likely to comply with medical advice if the healthcare provider seems disrespectful of the patient or appears to hold negative stereotypes of the patients' race, class, or other characteristics.
See also
Physician
Against medical advice
Duty of care
Standard of care
Scope of practice
Medical direction
Legal advice
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https://en.wikipedia.org/wiki/RelayNet
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RelayNet was an e-mail exchange network used by PCBoard bulletin board systems (BBS's). By 1990, RelayNet comprised more than 200 bulletin board systems. BBS's on RelayNet communicated via a communications protocol called RIME (RelayNet International Mail Exchange).
RelayNet was similar to FidoNet in purpose and technology, although it used names for its nodes instead of Fido's numeric address pairs. Due to it being limited to PCBoard, it carried a much smaller amount of traffic than Fido. RIME was built up, starting in 1988, from a master hub owned by Bonnie Anthony, a local Psychiatrist, in Bethesda, Maryland and a subordinate hub owned by her brother, Howard Belasco, in The Bronx, New York. Kip Compton, in high-school at the time, played an important role in the software's development and evolution. Dr. Anthony died in 2015.
PCBoard, created by Clark Development Corporation (CDC) in Salt Lake City, Utah, was always a "premium" BBS system and fairly expensive. For this reason it was limited mostly to larger multi-line BBS systems, where it was particularly well liked due to its "nice" behaviour on the network when running off a common file server. However this also meant that the PCBoard market generally consisted of a small number of large systems, as opposed to a large number of small ones, hence RIME had usually only a few hundred member boards.
Thus RelayNet, which originally ran only on PCBoard, did not have the same level of infrastructure as FidoNet, and didn't build the sort of global organizational structure that FidoNet needed. Instead, RelayNet evolved as a series of smaller regional networks, including the NANET hosted by Canada Remote Systems, RoseNet hosted by their competitors Rose Media, QuebecNet, FINET, Smartnet, Intelec, ILink, U'NI-net, Friendsnet and others.
RelayNet software later appeared for a variety of other BBS systems, including RBBS, GAP, EIS, QBBS and Wildcat! BBS, but these systems also provided excellent FidoNet support and Rel
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https://en.wikipedia.org/wiki/Damerau%E2%80%93Levenshtein%20distance
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In information theory and computer science, the Damerau–Levenshtein distance (named after Frederick J. Damerau and Vladimir I. Levenshtein) is a string metric for measuring the edit distance between two sequences. Informally, the Damerau–Levenshtein distance between two words is the minimum number of operations (consisting of insertions, deletions or substitutions of a single character, or transposition of two adjacent characters) required to change one word into the other.
The Damerau–Levenshtein distance differs from the classical Levenshtein distance by including transpositions among its allowable operations in addition to the three classical single-character edit operations (insertions, deletions and substitutions).
In his seminal paper, Damerau stated that in an investigation of spelling errors for an information-retrieval system, more than 80% were a result of a single error of one of the four types. Damerau's paper considered only misspellings that could be corrected with at most one edit operation. While the original motivation was to measure distance between human misspellings to improve applications such as spell checkers, Damerau–Levenshtein distance has also seen uses in biology to measure the variation between protein sequences.
Definition
To express the Damerau–Levenshtein distance between two strings and , a function is defined, whose value is a distance between an prefix (initial substring) of string and a prefix of .
The restricted distance function is defined recursively as:
where is the indicator function equal to 0 when and equal to 1 otherwise.
Each recursive call matches one of the cases covered by the Damerau–Levenshtein distance:
corresponds to a deletion (from a to b),
corresponds to an insertion (from a to b),
corresponds to a match or mismatch, depending on whether the respective symbols are the same,
corresponds to a transposition between two successive symbols.
The Damerau–Levenshtein distance between and is then
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https://en.wikipedia.org/wiki/Oskar%20Klein%20Memorial%20Lecture
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The Oskar Klein Memorial Lecture at Stockholm University, dedicated to the memory of the Swedish physicist Oskar Klein (1894-1977), is held annually since 1988 by a prominent physicist, who also receives the Oskar Klein Medal. The lecture is sponsored by the university and the Nobel Committee of the Royal Swedish Academy of Sciences.
List of lecturers and recipients of the Medal
Source:
2022 - Igor R. Klebanov
2020 - Roy Kerr
2019 - Lisa Randall
2018 - Leonard Susskind
2017 - Sheldon Glashow
2016 - Kip S. Thorne
2015 - Rashid Sunyaev
2014 - Andrew Strominger
2013 - Frank Wilczek
2012 - Juan Maldacena
2011 - Joseph Silk
2010 - Alexei A. Starobinsky
2009 - Peter Higgs
2008 - Helen Quinn
2007 - Gabriele Veneziano
2006 - Viatcheslav Mukhanov
2005 - Yoichiro Nambu
2004 - Pierre Ramond
2003 - Stephen Hawking
2002 - Martin Rees
2001 - Andrei Linde
2000 - David Gross
1999 - Gerard 't Hooft
1998 - Edward Witten
1997 - P. J. E. Peebles
1996 - Alexander Polyakov
1995 - Nathan Seiberg
1994 - The Oskar Klein Centenary Symposium, September 19-21, 1994
1993 - Tsung-Dao Lee
1992 - John A. Wheeler
1991 - Alan Guth
1990 - Hans Bethe
1989 - Steven Weinberg
1988 - Chen Ning Yang
See also
Lise Meitner Distinguished Lecture
List of physics awards
External links
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https://en.wikipedia.org/wiki/Geography%20%28Ptolemy%29
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The Geography (, Geōgraphikḕ Hyphḗgēsis, "Geographical Guidance"), also known by its Latin names as the and the , is a gazetteer, an atlas, and a treatise on cartography, compiling the geographical knowledge of the 2nd-century Roman Empire. Originally written by Claudius Ptolemy in Greek at Alexandria around AD 150, the work was a revision of a now-lost atlas by Marinus of Tyre using additional Roman and Persian gazetteers and new principles. Its translation into Arabic in the 9th century was highly influential on the geographical knowledge and cartographic traditions of the Islamic world. Alongside the works of Islamic scholars - and the commentary containing revised and more accurate data by Alfraganus - Ptolemy's work was subsequently highly influential on Medieval and Renaissance Europe.
Manuscripts
Versions of Ptolemy's work in antiquity were probably proper atlases with attached maps, although some scholars believe that the references to maps in the text were later additions.
No Greek manuscript of the Geography survives from earlier than the 13th century. A letter written by the Byzantine monk Maximus Planudes records that he searched for one for Chora Monastery in the summer of 1295; one of the earliest surviving texts may have been one of those he then assembled. In Europe, maps were sometimes redrawn using the coordinates provided by the text, as Planudes was forced to do. Later scribes and publishers could then copy these new maps, as Athanasius did for the emperor Andronicus II Palaeologus. The three earliest surviving texts with maps are those from Constantinople (Istanbul) based on Planudes's work.
The first Latin translation of these texts was made in 1406 or 1407 by Jacobus Angelus in Florence, Italy, under the name . It is not thought that his edition had maps, although Manuel Chrysoloras had given Palla Strozzi a Greek copy of Planudes's maps in Florence in 1397.
Contents
The Geography consists of three sections, divided among 8 books. Book
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https://en.wikipedia.org/wiki/Secure%20Hypertext%20Transfer%20Protocol
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Secure Hypertext Transfer Protocol (S-HTTP) is an obsolete alternative to the HTTPS protocol for encrypting web communications carried over the Internet. It was developed by Eric Rescorla and Allan M. Schiffman at EIT in 1994 and published in 1999 as .
Even though S-HTTP was first to market, Netscape's dominance of the browser market led to HTTPS becoming the de facto method for securing web communications.
Comparison to HTTP over TLS (HTTPS)
S-HTTP encrypts only the served page data and submitted data like POST fields, leaving the initiation of the protocol unchanged. Because of this, S-HTTP could be used concurrently with HTTP (unsecured) on the same port, as the unencrypted header would determine whether the rest of the transmission is encrypted.
In contrast, HTTP over TLS wraps the entire communication within Transport Layer Security (TLS; formerly SSL), so the encryption starts before any protocol data is sent. This creates a name-based virtual hosting "chicken and egg" issue with determining which DNS name was intended for the request.
This means that HTTPS implementations without Server Name Indication (SNI) support require a separate IP address per DNS name, and all HTTPS implementations require a separate port (usually 443 vs. HTTP's standard 80) for unambiguous use of encryption (treated in most browsers as a separate URI scheme, https://).
As documented in RFC 2817, HTTP can also be secured by implementing HTTP/1.1 Upgrade headers and upgrading to TLS. Running HTTP over TLS negotiated in this way does not have the implications of HTTPS with regards to name-based virtual hosting (no extra IP addresses, ports, or URI space). However, few implementations support this method.
In S-HTTP, the desired URL is not transmitted in the cleartext headers, but left blank; another set of headers is present inside the encrypted payload. In HTTP over TLS, all headers are inside the encrypted payload and the server application does not generally have the opportunity
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https://en.wikipedia.org/wiki/PC%C2%B2
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PC² is the Programming Contest Control System developed at California State University, Sacramento in support of Computer Programming Contest activities of the ACM, and in particular the ACM International Collegiate Programming Contest. It was used to conduct the ACM ICPC World Finals in 1990 and from 1994 through 2009. In 2010, the ACM ICPC World Finals switched to using Kattis, the KTH automated teaching tool; however, PC2 continues to be used for a large number of ICPC Regional Contests around the world.
Computer programming contests and PC²
Computer programming contest have rules and methods for judging submissions. The following describes in a general way a contest where PC2 is used.
A computer programming contest is a competition where teams submit (computer program) solutions to judges. The teams
are given a set of problems to solve in a limited amount of time (for example 8-13 problems in 5 hours).
The judges then give pass/fail judgements to the submitted solutions. Team rankings are computed based on the solutions, when the solutions were submitted and how many attempts were made to solve the problem. The judges test in a Black box testing where the teams do not have access to the judges' test data.
PC2 manages single or multi-site programming contests. It provides a team a way to log in, test solutions, submit solutions and view judgements from judges. PC2 provides judges a way to request team solutions (from a PC2 server) run/execute the solution and enter a judgment. The PC2 scoreboard module computes and creates standings and statistics web pages (HTML/XML). PC2 is easy to install on Linux/Linux-like systems and MS Windows and does not require super-user (root) access to install it or use it: this makes it an attractive choice for users who may not have super-user access.
Usage and User Experiences
PC2 was used for the ACM International Collegiate Programming Contest World Finals from 1994 to 2009. It has also been used in hundreds of ICPC Regio
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https://en.wikipedia.org/wiki/Inner%20sphere%20electron%20transfer
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Inner sphere electron transfer (IS ET) or bonded electron transfer is a redox chemical reaction that proceeds via a covalent linkage—a strong electronic interaction—between the oxidant and the reductant reactants. In inner sphere electron transfer, a ligand bridges the two metal redox centers during the electron transfer event. Inner sphere reactions are inhibited by large ligands, which prevent the formation of the crucial bridged intermediate. Thus, inner sphere ET is rare in biological systems, where redox sites are often shielded by bulky proteins. Inner sphere ET is usually used to describe reactions involving transition metal complexes and most of this article is written from this perspective. However, redox centers can consist of organic groups rather than metal centers.
The bridging ligand could be virtually any entity that can convey electrons. Typically, such a ligand has more than one lone electron pair, such that it can serve as an electron donor to both the reductant and the oxidant. Common bridging ligands include the halides and the pseudohalides such as hydroxide and thiocyanate. More complex bridging ligands are also well known including oxalate, malonate, and pyrazine. Prior to ET, the bridged complex must form, and such processes are often highly reversible. Electron transfer occurs through the bridge once it is established. In some cases, the stable bridged structure may exist in the ground state; in other cases, the bridged structure may be a transiently-formed intermediate, or else as a transition state during the reaction.
The alternative to inner sphere electron transfer is outer sphere electron transfer. In any transition metal redox process, the mechanism can be assumed to be outer sphere unless the conditions of the inner sphere are met. Inner sphere electron transfer is generally enthalpically more favorable than outer sphere electron transfer due to a larger degree of interaction between the metal centers involved, however,
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https://en.wikipedia.org/wiki/Ascaridole
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Ascaridole is a natural organic compound classified as a bicyclic monoterpenoid that has an unusual bridging peroxide functional group. It is a colorless liquid with a pungent smell and taste that is soluble in most organic solvents. Like other low molecular weight organic peroxides, it is unstable and prone to rapid decomposition when heated or treated with organic acids. Ascaridole determines the specific flavor of the Chilean tree boldo and is a major constituent of the oil of Mexican tea (wormseed). It is a component of natural medicine, tonic drinks and food flavoring in Latin American cuisine. As part of the oil, ascaridole is used as an anthelmintic drug that expels parasitic worms from plants, domestic animals and the human body.
History
Ascaridole was the first, and for a long time only, discovered naturally occurring organic peroxide. It was isolated from Chenopodium oil and named by Hüthig in 1908. He found that when heated to between 130° and 150° C "there occurs, with sudden boiling in which the temperature momentarily rises to about 250°, a decomposition of an explosive character, occasionally accompanied by ignition. At the same time a very disagreeable skatol-like odour, difficult to define, is observed. In the course of the examination it was found that during the decomposition a gas is split off." He determined its chemical formula as C10H16O2. Hüthig also noted the indifference of ascaridole to aldehydes, ketones or phenols that characterized it as non-alcohol. When reacted with sulfuric acid, or reduced with zinc powder and acetic acid, ascaridole formed cymene. A detailed study was done by E. K. Nelson in 1911. He described the decomposition as apparently a molecular rearrangement, and found that it reacts with sulfuric, hydrochloric, nitric, or phosphoric acids. Nelson showed that the new substance contained neither a hydroxyl nor a carbonyl group and that upon reduction with iron(II) sulfate it formed a glycol, now known as ascaridole glycol
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https://en.wikipedia.org/wiki/Outer%20sphere%20electron%20transfer
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Outer sphere refers to an electron transfer (ET) event that occurs between chemical species that remain separate and intact before, during, and after the ET event. In contrast, for inner sphere electron transfer the participating redox sites undergoing ET become connected by a chemical bridge. Because the ET in outer sphere electron transfer occurs between two non-connected species, the electron is forced to move through space from one redox center to the other.
Marcus theory
The main theory that describes the rates of outer sphere electron transfer was developed by Rudolph A. Marcus in the 1950s. A major aspect of Marcus theory is the dependence of the electron transfer rate on the thermodynamic driving force (difference in the redox potentials of the electron-exchanging sites). For most reactions, the rates increase with increased driving force. A second aspect is that the rate of outer sphere electron-transfer depends inversely on the "reorganizational energy." Reorganization energy describes the changes in bond lengths and angles that are required for the oxidant and reductant to switch their oxidation states. This energy is assessed by measurements of the self-exchange rates (see below).
Outer sphere electron transfer is the most common type of electron transfer, especially in biochemistry, where redox centers are separated by several (up to about 11) angstroms by intervening protein. In biochemistry, there are two main types of outer sphere ET: ET between two biological molecules or fixed distance electron transfer, in which the electron transfers within a single biomolecule (e.g., intraprotein).
Examples
Self-exchange
Outer sphere electron transfer can occur between chemical species that are identical except for their oxidation state. This process is termed self-exchange. An example is the degenerate reaction between the tetrahedral ions permanganate and manganate:
[MnO4]− + [Mn*O4]2− → [MnO4]2− + [Mn*O4]−
For octahedral metal complexes, the rate co
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https://en.wikipedia.org/wiki/Marcus%20theory
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In theoretical chemistry, Marcus theory is a theory originally developed by Rudolph A. Marcus, starting in 1956, to explain the rates of electron transfer reactions – the rate at which an electron can move or jump from one chemical species (called the electron donor) to another (called the electron acceptor). It was originally formulated to address outer sphere electron transfer reactions, in which the two chemical species only change in their charge with an electron jumping (e.g. the oxidation of an ion like Fe2+/Fe3+), but do not undergo large structural changes. It was extended to include inner sphere electron transfer contributions, in which a change of distances or geometry in the solvation or coordination shells of the two chemical species is taken into account (the Fe-O distances in Fe(H2O)2+ and Fe(H2O)3+ are different).
For electron transfer reactions without making or breaking bonds Marcus theory takes the place of Eyring's transition state theory which has been derived for reactions with structural changes. Both theories lead to rate equations of the same exponential form. However, whereas in Eyring theory the reaction partners become strongly coupled in the course of the reaction to form a structurally defined activated complex, in Marcus theory they are weakly coupled and retain their individuality. It is the thermally induced reorganization of the surroundings, the solvent (outer sphere) and the solvent sheath or the ligands (inner sphere) which create the geometrically favourable situation prior to and independent of the electron jump.
The original classical Marcus theory for outer sphere electron transfer reactions demonstrates the importance of the solvent and leads the way to the calculation of the Gibbs free energy of activation, using the polarization properties of the solvent, the size of the reactants, the transfer distance and the Gibbs free energy of the redox reaction. The most startling result of Marcus' theory was the "inverted region"
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https://en.wikipedia.org/wiki/George%20Laurer
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George Joseph Laurer III (September 23, 1925 – December 5, 2019) was an American engineer for IBM at Research Triangle Park in North Carolina. He published 20 bulletins, held 28 patents and developed the Universal Product Code (UPC) in the early 1970s. He devised the coding and pattern used for the UPC, based on Joe Woodland's more general idea for barcodes.
Early life
George Laurer was born on September 23, 1925, in New York City. His family moved to Baltimore, Maryland, so his father, an electrical engineer, could work for the United States Navy. Laurer recovered from polio which he contracted as a teenager, nonetheless, while in 11th grade, he was drafted into the U.S. Army during World War II. After being discharged from the military, he attended technical school where he studied radio and television repair. Upon completion of his first year at the technical school, his instructor convinced him that he should not continue that course of study, but that he should go to college. Laurer graduated from the A. James Clark School of Engineering at the University of Maryland in 1951. He was still interested in radio and kept up his amateur radio licence.
Career
Laurer was a 36-year employee of IBM until his retirement in June 1987. He joined IBM in 1951 as a junior engineer. By 1969, he had been promoted to senior engineer / scientist and moved to the company's offices in Research Triangle Park in North Carolina.
At IBM, Laurer was assigned the task of developing barcodes for use in grocery stores. Initially, IBM envisioned a circular bullseye pattern as proposed by Joe Woodland in 1940s. Laurer realized that the pattern was ineffective because of smearing during printing. Instead, he designed a vertical pattern of stripes which he proposed to his superior in 1971 or 1972. This change was accepted by IBM management and Laurer then worked with Woodland and mathematician David Savir to develop and refine the details. These included the addition of a check digit to p
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https://en.wikipedia.org/wiki/Air%20track
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The Air Track may also refer to a breakdance move.
See also AirTrack (disambiguation) for other uses.
An air track is a scientific device used to study motion in a low friction environment. Its name comes from its structure: air is pumped through a hollow track with fine holes all along the track that allows specially fitted air track cars to glide relatively friction-free. Air tracks are usually triangular in cross-section. Carts which have a triangular base and fit neatly on to the top of the track are used to study motion in low friction environments.
The air track is also used to study collisions, both elastic and inelastic. Since there is very little energy lost through friction it is easy to demonstrate how momentum is conserved before and after a collision. The track can be used to calculate the force of gravity when placed at an angle.
It was invented in the mid-1960s at the California Institute of Technology by Prof Nehr and Leighton. It was first presented by them at a meeting of the American Physical Society in NYC in 1965(?) where it was viewed by Prof John Stull, Alfred University, and Frank Ferguson, the Ealing Corporation. The original track was about 1 meter long with tiny air orifices and highly compressed air. Stull returned to Alfred University, where he developed a simple version using standard square aluminum tubing with large air orifices and air from the vent of a shop vacuum cleaner. With Ferguson's help at Ealing, Stull designed a custom aluminum track that Ealing offered commercially in various lengths up to 10 meters. T. Walley Williams III at Ealing extended the concept to the 2-dimensional air table in 1969.
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https://en.wikipedia.org/wiki/Retinoic%20acid
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Retinoic acid (used simplified here for all-trans-retinoic acid) is a metabolite of vitamin A1 (all-trans-retinol) that mediates the functions of vitamin A1 required for growth and development. All-trans-retinoic acid is required in chordate animals, which includes all higher animals from fish to humans. During early embryonic development, all-trans-retinoic acid generated in a specific region of the embryo helps determine position along the embryonic anterior/posterior axis by serving as an intercellular signaling molecule that guides development of the posterior portion of the embryo. It acts through Hox genes, which ultimately control anterior/posterior patterning in early developmental stages.
All-trans-retinoic acid (ATRA) is the major occurring retinoic acid, while isomers like 13-cis- and 9-cis-retinoic acid are also present in much lower levels.
The key role of all-trans-retinoic acid in embryonic development mediates the high teratogenicity of retinoid pharmaceuticals, such as isotretinoin (13-cis-retinoic acid) used for treatment of cancer and acne. Oral megadoses of preformed vitamin A (retinyl palmitate), and all-trans-retinoic acid itself, also have teratogenic potential by this same mechanism.
Mechanism of biological action
All-trans-retinoic acid acts by binding to the retinoic acid receptor (RAR), which is bound to DNA as a heterodimer with the retinoid X receptor (RXR) in regions called retinoic acid response elements (RAREs). Binding of the all-trans-retinoic acid ligand to RAR alters the conformation of the RAR, which affects the binding of other proteins that either induce or repress transcription of a nearby gene (including Hox genes and several other target genes). RARs mediate transcription of different sets of genes controlling differentiation of a variety of cell types, thus the target genes regulated depend upon the target cells. In some cells, one of the target genes is the gene for the retinoic acid receptor itself (RAR-beta in mamm
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https://en.wikipedia.org/wiki/Pneumatic%20actuator
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A pneumatic control valve actuator converts energy (typically in the form of compressed air) into mechanical motion. The motion can be rotary or linear, depending on the type of actuator.
Principle of operation
A pneumatic actuator mainly consists of a piston or a diaphragm which develops the motive power. It keeps the air in the upper portion of the cylinder, allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element.
Valves require little pressure to operate and usually double or triple the input force. The larger the size of the piston, the larger the output pressure can be. Having a larger piston can also be good if the air supply is low, allowing the same forces with less input. These pressures are large enough to crush objects in the pipe. On 100 kPa input, you could lift a small car (upwards of 1,000 lbs) easily, and this is only a basic, small pneumatic valve. However, the resulting forces required of the stem would be too great and cause the valve stem to fail.
This pressure is transferred to the valve stem, which is connected to either the valve plug (see plug valve), butterfly valve etc. Larger forces are required in high pressure or high flow pipelines to allow the valve to overcome these forces, and allow it to move the valves moving parts to control the material flowing inside.
The valve's input is the "control signal." This can come from a variety of measuring devices, and each different pressure is a different set point for a valve. A typical standard signal is 20–100 kPa. For example, a valve could be controlling the pressure in a vessel that has a constant out-flow, and a varied in-flow (varied by the actuator and valve). A pressure transmitter will monitor the pressure in the vessel and transmit a signal from 20–100 kPa. 20 kPa means there is no pressure, 100 kPa means there is full range pressure (can be varied by the transmitters calibration points). As the pressure rises in
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https://en.wikipedia.org/wiki/Process%20capability%20index
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The process capability index, or process capability ratio, is a statistical measure of process capability: the ability of an engineering process to produce an output within specification limits. The concept of process capability only holds meaning for processes that are in a state of statistical control. This means it cannot account for deviations which are not expected, such as misaligned, damaged, or worn equipment. Process capability indices measure how much "natural variation" a process experiences relative to its specification limits, and allows different processes to be compared to how well an organization controls them. Somewhat counterintuitively, higher index values indicate better performance, with zero indicating high deviation.
Example for non-specialists
A company produces axles with nominal diameter 20 mm on a lathe. As no axle can be made to exactly 20 mm, the designer specifies the maximum admissible deviations (called tolerances or specification limits). For instance, the requirement could be that axles need to be between 19.9 and 20.2 mm. The process capability index is a measure for how likely it is that a produced axle satisfies this requirement. The index pertains to statistical (natural) variations only. These are variations that naturally occur without a specific cause. Errors not addressed include operator errors, or play in the lathe's mechanisms resulting in a wrong or unpredictable tool position. If errors of the latter kinds occur, the process is not in a state of statistical control. When this is the case, the process capability index is meaningless.
Introduction
If the upper and lower specification limits of the process are USL and LSL, the target process mean is T, the estimated mean of the process is and the estimated variability of the process (expressed as a standard deviation) is , then commonly accepted process capability indices include:
is estimated using the sample standard deviation.
Recommended values
Process capabilit
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https://en.wikipedia.org/wiki/Hand%20coding
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In computing, hand coding means editing the underlying representation of a document or a computer program, when tools that allow working on a higher level representation also exist. Typically this means editing the source code, or the textual representation of a document or program, instead of using a WYSIWYG editor that always displays an approximation of the final product. It may mean translating the whole or parts of the source code into machine language manually instead of using a compiler or an automatic translator.
Most commonly, it refers to directly writing HTML documents for the web (rather than in a specialized editor), or to writing a program or portion of a program in assembly language (more rarely raw machine code) rather than in a higher level language. It can also include other markup languages, such as wikitext.
Purpose
The reasons to use hand coding include the ability to:
Use features or refinements not supported by the graphical editor or compiler
Control the semantics of a document beyond that allowed by the graphical editor
Produce more elegant source code to help maintenance and integration
Produce better performing machine code than that produced by the compiler (see optimization)
Avoid having to pay for expensive WYSIWYG Editors. Note that there are some open-source editors available on the web, however.
Develop an understanding of the methods underlying a common level of abstraction. For example, although it has become rare in real-life scenarios, computer science students may be required to write a program in an assembly language to get a notion of processor registers and other basal elements of computer architecture.
Escape abstractions and templated code. Hand coding allows more refined control of code, which may improve efficiency, or add functionality that is otherwise unavailable.
Hand coding may require more expertise and time than using automatic tools.
Hand code
Hand code is source code which does not have tools that c
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https://en.wikipedia.org/wiki/Enteric%20fermentation
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Enteric fermentation is a digestive process by which carbohydrates are broken down by microorganisms into simple molecules for absorption into the bloodstream of an animal. Because of human agricultural reliance in many parts of the world on animals which digest by enteric fermentation, it is the second largest anthropogenic factor for the increase in methane emissions directly after fossil fuel use.
Ruminants
Ruminant animals are those that have a rumen. A rumen is a multichambered stomach found almost exclusively among some artiodactyl mammals, such as cattle, sheep, and deer, enabling them to eat cellulose-enhanced tough plants and grains that monogastric (i.e., "single-chambered stomached") animals, such as humans, dogs, and cats, cannot digest. Although camels are thought to be ruminants they are not true ruminants.
Enteric fermentation occurs when methane (CH4) is produced in the rumen as microbial fermentation takes place. Over 200 species of microorganisms are present in the rumen, although only about 10% of these play an important role in digestion. Most of the CH4 byproduct is belched by the animal. However, a small percentage of CH4 is also produced in the large intestine and passed out as flatulence.
Methane emissions are an important contribution to global greenhouse gas emissions. The IPCC reports that methane is more than twenty times as effective as CO2 at trapping heat in the atmosphere - though note that it is produced in substantially smaller amounts. Methane represents also a significant energy loss to the animal ranging from 2 to 12% of gross energy intake. So, decreasing the production of enteric CH4 from ruminants without altering animal production is desirable both as a strategy to reduce global greenhouse gas emissions and as a means of improving feed conversion efficiency. In Australia ruminant animals account for over half of their green house gas contribution from methane.
However, in Australia there are ruminant species of the ka
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https://en.wikipedia.org/wiki/Ion%20Barbu
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Ion Barbu (, pen name of Dan Barbilian; 18 March 1895 –11 August 1961) was a Romanian mathematician and poet. His name is associated with the Mathematics Subject Classification number 51C05, which is a major posthumous recognition reserved only to pioneers of investigations in an area of mathematical inquiry.
Early life
Born in Câmpulung-Muscel, Argeș County, he was the son of Constantin Barbilian and Smaranda, born Șoiculescu. He attended elementary school in Câmpulung, Dămienești, and Stâlpeni, and for secondary studies he went to the Ion Brătianu High School in Pitești, the Dinicu Golescu High School in Câmpulung, and finally the Gheorghe Lazăr High School and the Mihai Viteazul High School in Bucharest. During that time, he discovered that he had a talent for mathematics, and started publishing in Gazeta Matematică; it was also then that he discovered his passion for poetry. Barbu was known as "one of the greatest Romanian poets of the twentieth century and perhaps the greatest of all" according to Romanian literary critic Alexandru Ciorănescu. As a poet, he is known for his volume Joc secund ("Mirrored Play").
He was a student at the University of Bucharest when World War I caused his studies to be interrupted by military service. He completed his degree in 1921. He then went to the University of Göttingen to study number theory with Edmund Landau for two years. Returning to Bucharest, he studied with Gheorghe Țițeica, completing in 1929 his thesis, Canonical representation of the addition of hyperelliptic functions.
Achievements in mathematics
Apollonian metric
In 1934, Barbilian published his article describing metrization of a region K, the interior of a simple closed curve J. Let xy denote the Euclidean distance from x to y. Barbilian's function for the distance from a to b in K is
At the University of Missouri in 1938 Leonard Blumenthal wrote Distance Geometry. A Study of the Development of Abstract Metrics, where he used the term "Barbilian spaces" f
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https://en.wikipedia.org/wiki/Anton%20Davidoglu
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Anton Davidoglu (June 30, 1876–May 27, 1958) was a Romanian mathematician who specialized in differential equations.
He was born in 1876 in Bârlad, Vaslui County, the son of Profira Moțoc and Doctor Cleante Davidoglu. His older brother was General Cleante Davidoglu.
He studied under Jacques Hadamard at the École Normale Supérieure in Paris, defending his Ph.D. dissertation in 1900. His thesis — the first mathematical investigation of deformable solids — applied Émile Picard's method of successive approximations to the study of fourth order differential equations that model traverse vibrations of non-homogeneous elastic bars.
After returning to Romania, Davidoglu became a professor at the University of Bucharest. In 1913, he was founding rector of the
Academy of High Commercial and Industrial Studies in Bucharest. He also continued to teach at the University of Bucharest, until his retirement in 1941.
Davidoglu was a founding member of the Romanian Academy of Sciences, and was featured on a 1976 Romanian postage stamp. He died in 1958 in Bucharest.
Publications
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https://en.wikipedia.org/wiki/Gheorghe%20Mihoc
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Gheorghe Mihoc (July 7, 1906 – December 25, 1981) was a Romanian mathematician and statistician.
He was born in Brăila, the son of Ecaterina and Gheorghe Mihoc, both originally from the Banat. In 1908, his father moved the family to Bucharest. Here he attended elementary school and the Gheorghe Șincai High School. In 1925 Mihoc enrolled at the University of Bucharest, Faculty of Sciences, and was awarded his degree in mathematics in June 1928.
He then went to Italy and studied statistics and actuarial studies at the University of Rome; he earned a Doctor of Statistical and Actuarial Sciences in July 1930, under the direction of Guido Castelnuovo. In 1930 he was appointed professor in the School of Statistics, Actuarial Studies, and Calculation, which had been established that year (it later became an Institute). The school was headed by Octav Onicescu. There Mihoc taught courses in actuarial mathematics from 1930 to 1948.
On April 28, 1934, he earned his Doctorate in Mathematics from the University of Bucharest, in front of a commission consisting of Dimitrie Pompeiu, as chairman, Anton Davidoglu, and Onicescu. The subject of his thesis, written under the direction of Onicescu, was On the general properties of interdependent statistical variables.
From 1937, Mihoc went to the University of Bucharest as assistant to Octav Onicescu, first at mechanics, then at algebra and probabilities calculation (1937–1942). That same year (1937) he also taught general mathematics with the students from the preparation year of Politehnica University of Bucharest. Between 1942 and 1946 he was conference lecturer of general mathematics at the Faculty of Physics and Chemistry of the University of Bucharest. Then, in 1946, he was appointed professor at the Academy of Higher-level Commercial and Industrial Studies, for financial mathematics (1946–1949).
In 1948, after the reform of education in all degrees, he was appointed head of the department of probability calculation and math
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https://en.wikipedia.org/wiki/Dimitrie%20Pompeiu
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Dimitrie D. Pompeiu (; – 8 October 1954) was a Romanian mathematician, professor at the University of Bucharest, titular member of the Romanian Academy, and President of the Chamber of Deputies.
Biography
He was born in 1873 in Broscăuți, Botoșani County, in a family of well-to-do peasants. After completing high school in nearby Dorohoi, he went to study at the Normal Teachers School in Bucharest, where he had Alexandru Odobescu as a teacher. After obtaining his diploma in 1893, he taught for five years at schools in Galați and Ploiești. In 1898 he went to France, where he studied mathematics at the University of Paris (the Sorbonne). He obtained his Ph.D. degree in mathematics in 1905, with thesis On the continuity of complex variable functions written under the direction of Henri Poincaré.
After returning to Romania, Pompeiu was named Professor of Mechanics at the University of Iași. In 1912, he assumed a chair at the University of Bucharest. In the early 1930s he was elected to the Chamber of Deputies as a member of Nicolae Iorga's Democratic Nationalist Party, and served as President of the Chamber of Deputies for a year. In 1934, Pompeiu was elected titular member of the Romanian Academy, while in 1943 he was elected to the Romanian Academy of Sciences. In 1945, he became the founding director of the Institute of Mathematics of the Romanian Academy.
He died in Bucharest in 1954. A boulevard in the Pipera neighborhood of the city is named after him, and so is a school in his hometown of Broscăuți.
Research
Pompeiu's contributions were mainly in the field of mathematical analysis, complex functions theory, and rational mechanics. In an article published in 1929, he posed a challenging conjecture in integral geometry, now widely known as the Pompeiu problem. Among his contributions to real analysis there is the construction, dated 1906, of non-constant, everywhere differentiable functions, with derivative vanishing on a dense set. Such derivatives are now ca
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https://en.wikipedia.org/wiki/Fairness%20measure
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Fairness measures or metrics are used in network engineering to determine whether users or applications are receiving a fair share of system resources. There are several mathematical and conceptual definitions of fairness.
Transmission Control Protocol fairness
Congestion control mechanisms for new network transmission protocols or peer-to-peer applications must interact well with Transmission Control Protocol (TCP). TCP fairness requires that a new protocol receive a no larger share of the network than a comparable TCP flow. This is important as TCP is the dominant transport protocol on the Internet, and if new protocols acquire unfair capacity they tend to cause problems such as congestion collapse. This was the case with the first versions of RealMedia's streaming protocol: it was based on UDP and was widely blocked at organizational firewalls until a TCP-based version was developed. TCP throughput unfairness over WiFi is a critical problem and needs further investigations.
Jain's fairness index
Raj Jain's equation,
rates the fairness of a set of values where there are users, is the throughput for the th connection, and is the sample coefficient of variation . The result ranges from (worst case) to 1 (best case), and it is maximum when all users receive the same allocation. This index is when users equally share the resource, and the other users receive zero allocation.
This metric identifies underutilized channels and is not unduly sensitive to atypical network flow patterns.
To achieve a given fairness level , one approximate method is to let , where
and A is an arbitrary factor, typically used for normalization. This gives an allocation with a fairness close to F, and the allocation can then be refined to get even closer. Note this also allows for a prioritization of allocation, as the s will be sorted.
An exact method is to let , where solves
.
A simple way to calculate is to use Newton's Method on , which converges consistently and fairly q
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https://en.wikipedia.org/wiki/Ring%20counter
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A ring counter is a type of counter composed of flip-flops connected into a shift register, with the output of the last flip-flop fed to the input of the first, making a "circular" or "ring" structure.
There are two types of ring counters:
A straight ring counter, also known as a one-hot counter, connects the output of the last shift register to the first shift register input and circulates a single one (or zero) bit around the ring.
A twisted ring counter, also called switch-tail ring counter, walking ring counter, Johnson counter, or Möbius counter, connects the complement of the output of the last shift register to the input of the first register and circulates a stream of ones followed by zeros around the ring.
Four-bit ring-counter sequences
Properties
Ring counters are often used in hardware design (e.g. ASIC and FPGA design) to create finite-state machines. A binary counter would require an adder circuit which is substantially more complex than a ring counter and has higher propagation delay as the number of bits increases, whereas the propagation delay of a ring counter will be nearly constant regardless of the number of bits in the code.
The straight and twisted forms have different properties, and relative advantages and disadvantages.
A general disadvantage of ring counters is that they are lower density codes than normal binary encodings of state numbers. A binary counter can represent 2N states, where N is the number of bits in the code, whereas a straight ring counter can represent only N states and a Johnson counter can represent only 2N states. This may be an important consideration in hardware implementations where registers are more expensive than combinational logic.
Johnson counters are sometimes favored, because they offer twice as many count states from the same number of shift registers, and because they are able to self-initialize from the all-zeros state, without requiring the first count bit to be injected externally at start
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https://en.wikipedia.org/wiki/BrookGPU
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The Brook programming language and its implementation BrookGPU were early and influential attempts to enable general-purpose computing on graphics processing units.
Brook, developed at Stanford University graphics group, was a compiler and runtime implementation of a stream programming language targeting modern, highly parallel GPUs such as those found on ATI or Nvidia graphics cards.
BrookGPU compiled programs written using the Brook stream programming language, which is a variant of ANSI C. It could target OpenGL v1.3+, DirectX v9+ or AMD's Close to Metal for the computational backend and ran on both Microsoft Windows and Linux. For debugging, BrookGPU could also simulate a virtual graphics card on the CPU.
Status
The last major beta release (v0.4) was in October 2004 but renewed development began and stopped again in November 2007 with a v0.5 beta 1 release.
The new features of v0.5 include a much upgraded and faster OpenGL backend which uses framebuffer objects instead of PBuffers and harmonised the code around standard OpenGL interfaces instead of using proprietary vendor extensions. GLSL support was added which brings all the functionality (complex branching and loops) previously only supported by DirectX 9 to OpenGL. In particular, this means that Brook is now just as capable on Linux as Windows.
Other improvements in the v0.5 series include multi-backend usage whereby different threads can run different Brook programs concurrently (thus maximising use of a multi-GPU setup) and SSE and OpenMP support for the CPU backend (this allows near maximal usage of modern CPUs).
Performance comparison
A like for like comparison between desktop CPUs and GPGPUs is problematic because of algorithmic & structural differences.
For example, a 2.66 GHz Intel Core 2 Duo can perform a maximum of 25 GFLOPs (25 billion single-precision floating-point operations per second) if optimally using SSE and streaming memory access so the prefetcher works perfectly. However, traditi
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https://en.wikipedia.org/wiki/Cyber-security%20regulation
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A cybersecurity regulation comprises directives that safeguard information technology and computer systems with the purpose of forcing companies and organizations to protect their systems and information from cyberattacks like viruses, worms, Trojan horses, phishing, denial of service (DOS) attacks, unauthorized access (stealing intellectual property or confidential information) and control system attacks. There are numerous measures available to prevent cyberattacks.
Cybersecurity measures include firewalls, anti-virus software, intrusion detection and prevention systems, encryption, and login passwords. There have been attempts to improve cybersecurity through regulation and collaborative efforts between the government and the private sector to encourage voluntary improvements to cybersecurity. Industry regulators, including banking regulators, have taken notice of the risk from cybersecurity and have either begun or planned to begin to include cybersecurity as an aspect of regulatory examinations.
Recent research suggests there is also a lack of cyber-security regulation and enforcement in maritime businesses, including the digital connectivity between ships and ports.
Background
In 2011 the DoD released a guidance called the Department of Defense Strategy for Operating in Cyberspace which articulated five goals: to treat cyberspace as an operational domain, to employ new defensive concepts to protect DoD networks and systems, to partner with other agencies and the private sector in pursuit of a "whole-of-government cybersecurity Strategy", to work with international allies in support of collective cybersecurity and to support the development of a cyber workforce capable of rapid technological innovation. A March 2011 GAO report "identified protecting the federal government's information systems and the nation's cyber critical infrastructure as a governmentwide high-risk area" noting that federal information security had been designated a high-risk area since
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https://en.wikipedia.org/wiki/Field%20capacity
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Field capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased. This usually takes place 2–3 days after rain or irrigation in pervious soils of uniform structure and texture. The physical definition of field capacity (expressed symbolically as θfc) is the bulk water content retained in soil at −33 kPa (or −0.33 bar) of hydraulic head or suction pressure. The term originated from Israelsen and West and Frank Veihmeyer and Arthur Hendrickson.
Veihmeyer and Hendrickson realized the limitation in this measurement and commented that it is affected by so many factors that, precisely, it is not a constant (for a particular soil), yet it does serve as a practical measure of soil water-holding capacity. Field capacity improves on the concept of moisture equivalent by Lyman Briggs. Veihmeyer & Hendrickson proposed this concept as an attempt to improve water-use efficiency for farmers in California during 1949.
Field capacity is characterized by measuring water content after wetting a soil profile, covering it (to prevent evaporation) and monitoring the change soil moisture in the profile. Water content when the rate of change is relatively small is indicative of when drainage ceases and is called Field Capacity, it is also termed drained upper limit (DUL).
Lorenzo A. Richards and Weaver found that water content held by soil at a potential of −33 kPa (or −0.33 bar) correlate closely with field capacity (−10 kPa for sandy soils).
Criticism
There is also criticism of this concept; field capacity is a static measurement: in a field it depends upon the initial water content and the depth of wetting before the commencement of redistribution and the rate of change in water content over time. These conditions are not unique for a given soil.
See also
Available water capacity
Integral energy
Nonlimiting water range
Pedotransfer function
Permanent wilting point
Water poten
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https://en.wikipedia.org/wiki/Moisture%20equivalent
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Moisture equivalent is proposed by Lyman Briggs and McLane (1910) as a measure of field capacity for fine-textured soil materials.
Moisture equivalent is defined as the percentage of water which a soil can retain in opposition to a centrifugal force 1000 times that of gravity. It is measured by saturating sample of soil 1 cm thick, and subjecting it to a centrifugal force of 1000 times gravity for 30 min. The gravimetric water content after this treatment is its moisture equivalent.
This concept is no longer used in soil physics, replaced by field capacity.
Lyman Briggs and Homer LeRoy Shantz (1912) found that:
Moisture Equivalent = 0.02 sand + 0.22 silt + 1.05 clay
Note: volume of water stored in root zone is equal to the depth of water in root zone (Vw=Dw)
See also
Available water capacity
Field capacity
Nonlimiting water range
Pedotransfer function
Permanent wilting point
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https://en.wikipedia.org/wiki/Permanent%20wilting%20point
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Permanent wilting point (PWP) or wilting point (WP) is defined as the minimum amount of water in the soil that the plant requires not to wilt. If the soil water content decreases to this or any lower point a plant wilts and can no longer recover its turgidity when placed in a saturated atmosphere for 12 hours. The physical definition of the wilting point, symbolically expressed as or , is said by convention as the water content at of suction pressure, or negative hydraulic head.
History
The concept was introduced in the early 1910s. Lyman Briggs and Homer LeRoy Shantz (1912) proposed the wilting coefficient, which is defined as the percentage water content of a soil when the plants growing in that soil are first reduced to a wilted condition from which they cannot recover in approximately saturated atmosphere without the addition of water to the soil. See pedotransfer function for wilting coefficient by Briggs.
Frank Veihmeyer and Arthur Hendrickson from University of California-Davis found that it is a constant (characteristic) of the soil and is independent of environmental conditions. Lorenzo A. Richards proposed it is taken as the soil water content when the soil is under a pressure of −15 bar.
See also
Available water capacity
Ecohydrology
Field capacity
Moisture equivalent
Moisture stress
Nonlimiting water range
Soil plant atmosphere continuum
Water retention curve
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https://en.wikipedia.org/wiki/Traian%20Lalescu
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Traian Lalescu (; 12 July 1882 – 15 June 1929) was a Romanian mathematician. His main focus was on integral equations and he contributed to work in the areas of functional equations, trigonometric series, mathematical physics, geometry, mechanics, algebra, and the history of mathematics.
Life
He went to the Carol I High School in Craiova, continuing high school in Roman, and graduating from the Boarding High School in Iași. After entering the University of Iași, he completed his undergraduate studies in 1903 at the University of Bucharest.
He earned his Ph.D. in Mathematics from the University of Paris in 1908. His dissertation, Sur les équations de Volterra, was written under the direction of Émile Picard. In 1911, he published Introduction to the Theory of Integral Equations, the first book ever on the subject of integral equations.
After returning to Romania in 1909, he first taught Mathematics at the Ion Maiorescu Gymnasium in Giurgiu. From 1909 to 1910, he was a teaching assistant at the School of Bridges and Highways, in the department of graphic statistics.
He was a professor at the University of Bucharest, the Polytechnic University of Timișoara (where he was the first rector, in 1920), and the Polytechnic University of Bucharest.
The Lalescu sequence
Legacy
There are several institutions bearing his name, including Colegiul Naţional de Informatică Traian Lalescu in Hunedoara and Liceul Teoretic Traian Lalescu in Reşiţa. There is also a Traian Lalescu Street in Timişoara.
The National Mathematics Contest Traian Lalescu for undergraduate students is also named after him.
A statue of Lalescu, carved in 1930 by Cornel Medrea, is situated in front of the Faculty of Mechanical Engineering, in Timişoara and another statue of Lalescu is situated inside the University of Bucharest.
Work
T. Lalesco, Introduction à la théorie des équations intégrales. Avec une préface de É. Picard, Paris: A. Hermann et Fils, 1912. VII + 152 pp. JFM entry
Traian Lalescu,
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https://en.wikipedia.org/wiki/Nonlimiting%20water%20range
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The non-limiting water range (NLWR) represents the range of water content in the soil where limitations to plant growth (such as water potential, air-filled porosity, or soil strength) are minimal. John Letey (1985) from UC Riverside introduced the NLWR concept in an attempt to integrate several physical properties associated with plant or root growth to refine the concept of available water capacity. Alvaro Pires da Silva, Bev Kay, and Ed Perfect (University of Guelph, Ontario) (1994) refined the concept and termed it least limiting water range (LLWR).
The upper limit (wet end) of LLWR is determined not only by water content at field capacity (FC), but also the capability of providing adequate aeration for plant roots (usually taken as a minimum air filled porosity of 10%). The upper limit is then defined as:
min q {air filled porosity = 0.1, FC}.
Rather than air-filled porosity at 10%, LaoSheng Wu from UC Riverside proposed moisture content where Oxygen gas diffusion rate ODR value of 0.2 micro-g/cm2/min as criteria for satisfactory aeration status.
The lower limit (dry end) is not only limited to permanent wilting point (PWP) but also the ability of root penetration. This is measured as soil mechanical resistance taken at an arbitrary value, say penetration at 3 MPa.
The lower limit is defined as:
max q {mechanical resistance = 3 MPa, PWP}.
See also
Integral energy
Irrigation scheduling
Limiting factor
Moisture equivalent
Moisture stress
Pedotransfer function
Soil plant atmosphere continuum
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https://en.wikipedia.org/wiki/Branching%20%28version%20control%29
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Branching, in version control and software configuration management, is the duplication of an object under version control (such as a source code file or a directory tree). Each object can thereafter be modified separately and in parallel so that the objects become different. In this context the objects are called branches. The users of the version control system can branch any branch.
Branches are also known as trees, streams or codelines. The originating branch is sometimes called the parent branch, the upstream branch (or simply upstream, especially if the branches are maintained by different organizations or individuals), or the backing stream.
Child branches are branches that have a parent; a branch without a parent is referred to as the trunk or the mainline. The trunk is also sometimes loosely referred to as HEAD, but properly head refers not to a branch, but to the most recent commit on a given branch, and both the trunk and each named branch has its own head. The trunk is usually meant to be the base of a project on which development progresses. If developers are working exclusively on the trunk, it always contains the latest cutting-edge version of the project, but therefore may also be the most unstable version. Another approach is to split a branch off the trunk, implement changes in that branch and merge the changes back into the trunk when the branch has proven to be stable and working. Depending on development mode and commit policy the trunk may contain the most stable or the least stable or something-in-between version. Other terms for trunk include baseline, mainline, and master, though in some cases these are used with similar but distinct senses – see . Often main developer work takes place in the trunk and stable versions are branched, and occasional bug-fixes are merged from branches to the trunk. When development of future versions is done in non-trunk branches, it is usually done for projects that do not change often, or where a change is
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https://en.wikipedia.org/wiki/Pyramidal%20alkene
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Pyramidal alkenes are alkenes in which the two carbon atoms making up the double bond are not coplanar with their four substituents. This deformation results from geometric constraints. Pyramidal alkenes only are of interest because much can be learned from them about the nature of chemical bonding.
Energetics
Twisting to a 90° dihedral angle between two of the groups on the carbons requires less energy than the strength of a pi bond, and the bond still holds. The carbons of the double bond become pyramidal, which allows preserving some p orbital alignment—and hence pi bonding. The other two attached groups remain at a larger dihedral angle. This contradicts a common textbook assertion that the two carbons retain their planar nature when twisting, in which case the p orbitals would rotate enough away from each other to be unable to sustain a pi bond. In a 90°-twisted alkene, the p orbitals are only misaligned by 42° and the strain energy is only around 40 kcal/mol. In contrast, a fully broken pi bond has an energetic cost of around 65 kcal/mol.
Examples
In cycloheptene (1.1) the cis isomer is an ordinary unstrained molecule, but the heptane ring is too small to accommodate a trans-configured alkene group resulting in strain and twisting of the double bond. The p-orbital misalignment is minimized by a degree of pyramidalization. In the related anti-Bredt molecules. it is not pyrimidalization but twisting that dominates.
Pyramidalized cage alkenes also exist where symmetrical bending of the substituents predominates without p-orbital misalignment.
The pyramidalization angle φ (b) is defined as the angle between the plane defined by one of the doubly bonded carbons and its two substituents and the extension of the double bond and is calculated as:
the butterfly bending angle or folding angle ψ (c) is defined as the angle between two planes and can be obtained by averaging the two torsional angles R1C=CR3 and R2C=CR4.
In alkenes 1.2 and 1.3 these angles are deter
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https://en.wikipedia.org/wiki/Integral%20energy
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Integral energy is the amount of energy required to remove water from soil with an initial water content to water content of (where ). It is calculated by integrating the water retention curve, soil water potential with respect to :
It is proposed by Minasny and McBratney (2003) as alternative to available water capacity. (AWC)
The AWC concept assumes equal availability of water between two potentials and does not consider the path along the water retention curve. Integral energy takes into the account the path or energy (characterised by water retention curve) required to dry a soil at particular soil moisture content
See also
Available water capacity
Nonlimiting water range
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https://en.wikipedia.org/wiki/Thirring%20model
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The Thirring model is an exactly solvable quantum field theory which describes the self-interactions of a Dirac field in (1+1) dimensions.
Definition
The Thirring model is given by the Lagrangian density
where is the field, g is the coupling constant, m is the mass, and , for , are the two-dimensional gamma matrices.
This is the unique model of (1+1)-dimensional, Dirac fermions with a local (self-)interaction. Indeed, since there are only 4 independent fields, because of the Pauli principle, all the quartic, local interactions are equivalent; and all higher power, local interactions vanish. (Interactions containing derivatives, such as , are not considered because they are non-renormalizable.)
The correlation functions of the Thirring model (massive or massless) verify the Osterwalder–Schrader axioms, and hence the theory makes sense as a quantum field theory.
Massless case
The massless Thirring model is exactly solvable in the sense that a formula for the -points field correlation is known.
Exact solution
After it was introduced by Walter Thirring, many authors tried to solve the massless case, with confusing outcomes. The correct formula for the two and four point correlation was finally found by K. Johnson; then C. R. Hagen and B. Klaiber extended the explicit solution to any multipoint correlation function of the fields.
Massive Thirring model, or MTM
The mass spectrum of the model and the scattering matrix was explicitly evaluated by Bethe Ansatz. An explicit formula for the correlations is not known. J. I. Cirac, P. Maraner and J. K. Pachos applied the massive Thirring model to the description of optical lattices.
Exact solution
In one space dimension and one time dimension the model can be solved by the Bethe Ansatz. This helps one calculate exactly the mass spectrum
and scattering matrix. Calculation of the scattering matrix reproduces the results published earlier by Alexander Zamolodchikov. The paper with the exact solution of Massive Thirr
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https://en.wikipedia.org/wiki/Water%20retention%20curve
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Water retention curve is the relationship between the water content, θ, and the soil water potential, ψ. This curve is characteristic for different types of soil, and is also called the soil moisture characteristic.
It is used to predict the soil water storage, water supply to the plants (field capacity) and soil aggregate stability. Due to the hysteretic effect of water filling and draining the pores, different wetting and drying curves may be distinguished.
The general features of a water retention curve can be seen in the figure, in which the volume water content, θ, is plotted against the matric potential, . At potentials close to zero, a soil is close to saturation, and water is held in the soil primarily by capillary forces. As θ decreases, binding of the water becomes stronger, and at small potentials (more negative, approaching wilting point) water is strongly bound in the smallest of pores, at contact points between grains and as films bound by adsorptive forces around particles.
Sandy soils will involve mainly capillary binding, and will therefore release most of the water at higher potentials, while clayey soils, with adhesive and osmotic binding, will release water at lower (more negative) potentials. At any given potential, peaty soils will usually display much higher moisture contents than clayey soils, which would be expected to hold more water than sandy soils. The water holding capacity of any soil is due to the porosity and the nature of the bonding in the soil.
Curve models
The shape of water retention curves can be characterized by several models, one of them known as the Van Genuchten model:
where
is the water retention curve [L3L−3];
is suction pressure ([L] or cm of water);
saturated water content [L3L−3];
residual water content [L3L−3];
is related to the inverse of the air entry suction, ([L−1], or cm−1); and,
is a measure of the pore-size distribution, (dimensionless).
Based on this parametrization a prediction model for the
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https://en.wikipedia.org/wiki/Topkis%27s%20theorem
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In mathematical economics, Topkis's theorem is a result that is useful for establishing comparative statics. The theorem allows researchers to understand how the optimal value for a choice variable changes when a feature of the environment changes. The result states that if f is supermodular in (x,θ), and D is a lattice, then is nondecreasing in θ. The result is especially helpful for establishing comparative static results when the objective function is not differentiable. The result is named after Donald M. Topkis.
An example
This example will show how using Topkis's theorem gives the same result as using more standard tools. The advantage of using Topkis's theorem is that it can be applied to a wider class of problems than can be studied with standard economics tools.
A driver is driving down a highway and must choose a speed, s. Going faster is desirable, but is more likely to result in a crash. There is some prevalence of potholes, p. The presence of potholes increases the probability of crashing. Note that s is a choice variable and p is a parameter of the environment that is fixed from the perspective of the driver. The driver seeks to .
We would like to understand how the driver's speed (a choice variable) changes with the amount of potholes:
If one wanted to solve the problem with standard tools such as the implicit function theorem, one would have to assume that the problem is well behaved: U(.) is twice continuously differentiable, concave in s, that the domain over which s is defined is convex, and that it there is a unique maximizer for every value of p and that is in the interior of the set over which s is defined. Note that the optimal speed is a function of the amount of potholes. Taking the first order condition, we know that at the optimum, . Differentiating the first order condition, with respect to p and using the implicit function theorem, we find that
or that
So,
If s and p are substitutes,
and hence
and more
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https://en.wikipedia.org/wiki/BURS
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BURS (bottom-up rewrite system) theory tackles the problem of taking a complex expression tree or intermediate language term and finding a good translation to machine code for a particular architecture. Implementations of BURS often employ dynamic programming to solve this problem.
BURS can also be applied to the problem of designing an instruction set for an application-specific instruction set processor.
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https://en.wikipedia.org/wiki/LOCC
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LOCC, or local operations and classical communication, is a method in quantum information theory where a local (product) operation is performed on part of the system, and where the result of that operation is "communicated" classically to another part where usually another local operation is performed conditioned on the information received.
Mathematical properties
The formal definition of the set of LOCC operations is complicated due to the fact that later local operations depend in general on all the previous classical communication and due to the unbounded number of communication rounds. For any finite number one can define , the set of LOCC operations that can be achieved with rounds of classical communication. The set becomes strictly larger whenever is increased and care has to be taken to define the limit of infinitely many rounds. In particular, the set LOCC is not topologically closed, that is there are quantum operations that can be approximated arbitrarily closely by LOCC but that are not themselves LOCC.
A one-round LOCC is a quantum instrument , for which the trace-non-increasing completely positive maps (CPMs) are local for all measurement results , i.e., and there is one site such that only at the map is not trace-preserving. This means that the instrument can be realized by the party at site applying the (local) instrument and communicating the classical result to all other parties, which then each perform (conditioned on ) trace-preserving (deterministic) local quantum operations .
Then are defined recursively as those operations that can be realized by following up an operation with a -operation. Here it is allowed that the party which performs the follow-up operations depends on the result of the previous rounds. Moreover, we also allow "coarse-graining", i.e., discarding some of the classical information encoded in the measurement results (of all rounds).
The union of all operations is denoted by and contains instruments tha
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https://en.wikipedia.org/wiki/Disc%20permeameter
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The disc permeameter is a field instrument used for measuring water infiltration in the soil, which is characterized by in situ saturated and unsaturated soil hydraulic properties. It is mainly used to provide estimates of the hydraulic conductivity of the soil near saturation.
History
Conventional techniques for measuring in-situ infiltration include the use of a single or double ring infiltrometer. Single and double ring infiltrometer only measures flow under ponded (saturated) conditions, and when used in soil with distinct macropores, preferential flow will dominate the flow. (See: Poiseuille's law) This does not reflect infiltration under rainfall or sprinkler irrigation. Therefore, many authors attempted to create a negative potential (tension) on the water flow. This is to exclude macropores in the flow process, hence only measuring the soil matrix flow.
Willard Gardner and Walter Gardner developed a negative head permeameter as early as 1939. Dixon (1975) developed a closed-top ring infiltrometer to quantify macropores. Water is applied to a closed-top system, which permits the imposition of negative head or pressure on the ponded water surface. Negative tension can be considered as simulating a positive soil air pressure, created by a negative air pressure above ponded surface water. A simplification was made by Topp and Zebchuk (1985). The limitation of this device is the infiltration has to be started by ponding the closed-top infiltrometer (applying a positive head), then adjusted to a negative pressure. Little research effort was continued in this area, instead attention has been given mainly to the sorptivity apparatus of Dirksen (1975) which used a ceramic plate as a base. Based on this design, Brent Clothier and Ian White (1981) developed the sorptivity tube which can provide a constant negative potential (tension) on the soil surface. However, the sorptivity tube had many shortcomings, hence modifications to the design led to the development of th
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https://en.wikipedia.org/wiki/IEEE%201355
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IEEE Standard 1355-1995, IEC 14575, or ISO 14575 is a data communications standard for Heterogeneous Interconnect (HIC).
IEC 14575 is a low-cost, low latency, scalable serial interconnection system, originally intended for communication between large numbers of inexpensive computers.
IEC 14575 lacks many of the complexities of other data networks. The standard defined several different types of transmission media (including wires and optic fiber), to address different applications.
Since the high-level network logic is compatible, inexpensive electronic adapters are possible. IEEE 1355 is often used in scientific laboratories. Promoters include large laboratories, such as CERN, and scientific agencies.
For example, the ESA advocates a derivative standard called SpaceWire.
Goals
The protocol was designed for a simple, low cost switched network made of point-to-point links. This network sends variable length data packets reliably at high speed. It routes the packets using wormhole routing. Unlike Token Ring or other types of local area networks (LANs) with comparable specifications, IEEE 1355 scales beyond a thousand nodes without requiring higher transmission speeds. The network is designed to carry traffic from other types of networks, notably Internet Protocol and Asynchronous Transfer Mode (ATM), but does not depend on other protocols for data transfers or switching. In this, it resembles Multiprotocol Label Switching (MPLS).
IEEE 1355 had goals like Futurebus and its derivatives Scalable Coherent Interface (SCI), and InfiniBand. The packet routing system of IEEE 1355 is also similar to VPLS, and uses a packet labeling scheme similar to MPLS.
IEEE 1355 achieves its design goals with relatively simple digital electronics and very little software. This simplicity is valued by many engineers and scientists.
Paul Walker (see links ) said that when implemented in an FPGA, the standard takes about a third the hardware resources of a UART (a standard seria
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https://en.wikipedia.org/wiki/Rutherford%20Memorial%20Medal
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The Rutherford Memorial Medal is an award for research in the fields of physics and chemistry by the Royal Society of Canada. It was dedicated to the memory of Ernest Rutherford. It is awarded once for physics and once for chemistry each year, "for outstanding research", when there is a suitable candidate.
Recipients
Source: Royal Society of Canada
Chemistry
2022 : Aiping Yu
2021 : Fiorenzo Vetrone
2020 : Erin Johnson
2019 : Dwight Seferos
2018 : Tomislav Friscic
2017 : Zhongwei Chen
2016 : Curtis Berlinguette
2015 : Robert Campbell
2014 : Paul Ayers
2013 : Mark J. Maclachlan
2012 :
2011 : Federico Rosei
2010 : Andrei Yudin
2009 : Dennis Hall and Keith Fagnou (posthumously)
2008 : Peter Tieleman
2007 : Gregory D. Scholes
2006 : Molly Shoichet
2005 : Jillian M. Buriak
2004 : Andrew Woolley
2003 : Liang Li
2002 :
2001 :
2000 : Suning Wang
1999 : Daniel D. M. Wayner
1998 : Benoît Roux
1997 : R. J. Dwayne Miller
1996 :
1995 :
1994 : Mark Lautens
1993 :
1992 : James D. Wuest
1991 : Robert H. Morris
1990 :
1989 : Peter Hackett
1988 :
1987 : Grenfell N. Patey
1986 : David Griller
1985 : Stephen C. Wallace
1984 : Robert J. LeRoy
1983 : Juan C. Scaiano
1982 : Geoffrey Ozin
1981 : Diethard K. Böhme
1980 : G. Michael Bancroft
Physics
2022 : Daryl Haggard
2021 : Jo Bovy
2020 : Jens Dilling
2019 : Paul François
2018 : Alexandre Blais
2017 : Ingrid Stairs
2016 : François Légaré
2015 : Aashish Clerk
2014 : Sara Ellison
2013 : Ray Jayawardhana
2012 : Guy Moore
2011 : Freddy A. Cachazo
2010 : Kari Dalnoki-Veress
2009 : Barth Netterfield
2007 : Victoria Michelle Kaspi
2006 : Aephraim M. Steinberg
2005 : Peter Grütter
2004 : Sajeev John
2003 : Misha Ivanov
2002 : Christopher Thompson
2001 : Matthew W. Choptuik
2000 : Jerry X. Mitrovica
1999 : Robert A. Wolkow
1998 : Martin Grant
1997 : Nicholas Kaiser
1996 : Pekka K. Sinervo
1995 : David B. MacFarlane
1994 : Michael L.W. Thewalt
1993 : John W. Hepb
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https://en.wikipedia.org/wiki/Annealing%20%28materials%20science%29
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In metallurgy and materials science, annealing is a heat treatment that alters the physical and sometimes chemical properties of a material to increase its ductility and reduce its hardness, making it more workable. It involves heating a material above its recrystallization temperature, maintaining a suitable temperature for an appropriate amount of time and then cooling.
In annealing, atoms migrate in the crystal lattice and the number of dislocations decreases, leading to a change in ductility and hardness. As the material cools it recrystallizes. For many alloys, including carbon steel, the crystal grain size and phase composition, which ultimately determine the material properties, are dependent on the heating rate and cooling rate. Hot working or cold working after the annealing process alters the metal structure, so further heat treatments may be used to achieve the properties required. With knowledge of the composition and phase diagram, heat treatment can be used to adjust from harder and more brittle to softer and more ductile.
In the case of ferrous metals, such as steel, annealing is performed by heating the material (generally until glowing) for a while and then slowly letting it cool to room temperature in still air. Copper, silver and brass can be either cooled slowly in air, or quickly by quenching in water. In this fashion, the metal is softened and prepared for further work such as shaping, stamping, or forming.
Many other materials, including glass and plastic films, use annealing to improve the finished properties.
Thermodynamics
Annealing occurs by the diffusion of atoms within a solid material, so that the material progresses towards its equilibrium state. Heat increases the rate of diffusion by providing the energy needed to break bonds. The movement of atoms has the effect of redistributing and eradicating the dislocations in metals and (to a lesser extent) in ceramics. This alteration to existing dislocations allows a metal object to def
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https://en.wikipedia.org/wiki/Ranked%20society
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A ranked society in anthropology is one that ranks individuals in terms of their genealogical distance from the chief. Another term for a "ranked society" is a chiefdom. Closer relatives of the chief have higher rank or social status than more distant ones. Societies which follow this kind of structure associate rank with power, where other societies associate wealth with power. When individuals and groups rank about equally, competition for positions of leadership may occur. In some cases rank is assigned to entire villages rather than individuals or families. The idea of a ranked society was criticized by Max Weber and Karl Marx. Ranks in ranked society are the different levels, platforms, or social classes that determine someone’s influence on political aspects, votes, decision making, etc. A person’s ranking also gives them societal power (power within their civilisation).
See also
Rankism
Social class
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https://en.wikipedia.org/wiki/Kernel%20method
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In machine learning, kernel machines are a class of algorithms for pattern analysis, whose best known member is the support-vector machine (SVM). These methods involve using linear classifiers to solve nonlinear problems. The general task of pattern analysis is to find and study general types of relations (for example clusters, rankings, principal components, correlations, classifications) in datasets. For many algorithms that solve these tasks, the data in raw representation have to be explicitly transformed into feature vector representations via a user-specified feature map: in contrast, kernel methods require only a user-specified kernel, i.e., a similarity function over all pairs of data points computed using inner products. The feature map in kernel machines is infinite dimensional but only requires a finite dimensional matrix from user-input according to the Representer theorem. Kernel machines are slow to compute for datasets larger than a couple of thousand examples without parallel processing.
Kernel methods owe their name to the use of kernel functions, which enable them to operate in a high-dimensional, implicit feature space without ever computing the coordinates of the data in that space, but rather by simply computing the inner products between the images of all pairs of data in the feature space. This operation is often computationally cheaper than the explicit computation of the coordinates. This approach is called the "kernel trick". Kernel functions have been introduced for sequence data, graphs, text, images, as well as vectors.
Algorithms capable of operating with kernels include the kernel perceptron, support-vector machines (SVM), Gaussian processes, principal components analysis (PCA), canonical correlation analysis, ridge regression, spectral clustering, linear adaptive filters and many others.
Most kernel algorithms are based on convex optimization or eigenproblems and are statistically well-founded. Typically, their statistical prop
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https://en.wikipedia.org/wiki/Input%20shaping
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In control theory, input shaping is an open-loop control technique for reducing vibrations in computer-controlled machines. The method works by creating a command signal that cancels its own vibration. That is, a vibration excited by previous parts of the command signal is cancelled by vibration excited by latter parts of the command. Input shaping is implemented by convolving a sequence of impulses, known as an input shaper, with any arbitrary command. The shaped command that results from the convolution is then used to drive the system. If the impulses in the shaper are chosen correctly, then the shaped command will excite less residual vibration than the unshaped command. The amplitudes and time locations of the impulses are obtained from the system's natural frequencies and damping ratios. Shaping can be made very robust to errors in the system parameters.
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https://en.wikipedia.org/wiki/Aerospace%20architecture
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Aerospace architecture is broadly defined to encompass architectural design of non-habitable and habitable structures and living and working environments in aerospace-related facilities, habitats, and vehicles. These environments include, but are not limited to: science platform aircraft and aircraft-deployable systems; space vehicles, space stations, habitats and lunar and planetary surface construction bases; and Earth-based control, experiment, launch, logistics, payload, simulation and test facilities. Earth analogs to space applications may include Antarctic, desert, high altitude, underground, undersea environments and closed ecological systems.
The American Institute of Aeronautics and Astronautics (AIAA) Design Engineering Technical Committee (DETC) meets several times a year to discuss policy, education, standards, and practice issues pertaining to aerospace architecture.
The role of Appearance in Aerospace architecture
"The role of design creates and develops concepts and specifications that seek to simultaneously and synergistically optimize function, production, value and appearance." In connection with, and with respect to, human presence and interactions, appearance is a component of human factors and includes considerations of human characteristics, needs and interests.
Appearance in this context refers to all visual aspects – the statics and dynamics of form(s), color(s), patterns, and textures in respect to all products, systems, services, and experiences. Appearance/esthetics affects humans both psychologically and physiologically and can effect/improving both human efficiency, attitude, and well-being.
In reference to non-habitable design the influence of appearance is minimal if not non-existent. However, as the industry of aerospace continues to rapidly grow, and missions to put humans on Mars and back to the Moon are being announced. The role that appearance/esthetics to maintain crew well-being and health of multi-month or year missions b
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https://en.wikipedia.org/wiki/Armstrong%27s%20axioms
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Armstrong's axioms are a set of references (or, more precisely, inference rules) used to infer all the functional dependencies on a relational database. They were developed by William W. Armstrong in his 1974 paper. The axioms are sound in generating only functional dependencies in the closure of a set of functional dependencies (denoted as ) when applied to that set (denoted as ). They are also complete in that repeated application of these rules will generate all functional dependencies in the closure .
More formally, let denote a relational scheme over the set of attributes with a set of functional dependencies . We say that a functional dependency is logically implied by , and denote it with if and only if for every instance of that satisfies the functional dependencies in , also satisfies . We denote by the set of all functional dependencies that are logically implied by .
Furthermore, with respect to a set of inference rules , we say that a functional dependency is derivable from the functional dependencies in by the set of inference rules , and we denote it by if and only if is obtainable by means of repeatedly applying the inference rules in to functional dependencies in . We denote by the set of all functional dependencies that are derivable from by inference rules in .
Then, a set of inference rules is sound if and only if the following holds:
that is to say, we cannot derive by means of functional dependencies that are not logically implied by .
The set of inference rules is said to be complete if the following holds:
more simply put, we are able to derive by all the functional dependencies that are logically implied by .
Axioms (primary rules)
Let be a relation scheme over the set of attributes . Henceforth we will denote by letters , , any subset of and, for short, the union of two sets of attributes and by instead of the usual ; this notation is rather standard in database theory when dealing with sets of attributes.
A
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https://en.wikipedia.org/wiki/Lupus%20pernio
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Lupus pernio is a chronic raised indurated (hardened) lesion of the skin, often purplish in color. It is seen on the nose, ears, cheeks, lips, and forehead. It is pathognomonic of sarcoidosis. The name "lupus pernio" is a misnomer, as microscopically this disease shows granulomatous infiltration and does not have features of either lupus nor pernio.
Lupus pernio is associated with poor outcomes and lower rates of resolution.
Lupus pernio and erythema nodosum are cutaneous manifestation of sarcoidosis, may suggest this disease as a cause of an associated dilated cardiomyopathy, especially with heart block, intraventricular conduction delay, or ventricular tachycardia.
See also
Sarcoidosis
Skin manifestations of sarcoidosis
List of cutaneous conditions
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https://en.wikipedia.org/wiki/Caribbean%20Knowledge%20and%20Learning%20Network
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The Caribbean Knowledge and Learning Network (CKLN) is an inter-governmental agency of the Caribbean Community, CARICOM, responsible for developing and managing a high capacity, broadband fiber optic network called C@ribNET, connecting all CARICOM member states.
The Caribbean Knowledge Learning Network Agency was first proposed in 2002 at a meeting where the 7 Prime Ministers of Eastern Caribbean States and Barbados met with the president of the World Bank. It was established in 2004 as an institution of the CARICOM, under the authority of Article 21 of the Revised Treaty of Chaguaramas.
Academic computer network organizations
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https://en.wikipedia.org/wiki/Aquatic%20biomonitoring
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Aquatic biomonitoring is the science of inferring the ecological condition of rivers, lakes, streams, and wetlands by examining the organisms (fish, invertebrates, insects, plants, and algae) that live there. While aquatic biomonitoring is the most common form of biomonitoring, any ecosystem can be studied in this manner.
Purpose
Aquatic biomonitoring is an important tool for assessing aquatic life forms and their habitats. It can reveal the overall health and status of the ecosystem, detect environmental trends and the impacts of different stressors, and can be used to evaluate the effect that various human activities have on the overall health of aquatic environments. Water pollution and general stresses to aquatic life have a major impact on the environment. The main sources of pollution to oceans, rivers, and lakes are human caused events or activities, such as sewage, oil spills, surface runoff, littering, ocean mining, and nuclear waste.
Monitoring aquatic life can also be beneficial in monitoring and understanding adjacent land ecosystems. Rapid changes to an environment, like, pollution, can alter ecosystems and community assemblages, and endanger species that live in or close to water. Many aquatic species serve as food sources for terrestrial species, which are therefore impacted by the size and health of aquatic populations.
Indicator organisms
Aquatic invertebrates, most popularly the larvae of the caddis fly sp., are responsive to climate change, low levels of pollution and temperature change. As a result, they have the longest history of use in biomonitoring programs. Additionally, macroscopic species: frogs, fish, and some plant species, as well as, many forms of microscopic life, like bacteria and protozoa are used as indicator organisms in a variety of applications, storm water run-off among them.
Many species of Macroalgae (including Cyanobacteria, though not technically a true algae) are also used in biomonitoring for both aquatic and mar
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https://en.wikipedia.org/wiki/Amortization%20calculator
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An amortization calculator is used to determine the periodic payment amount due on a loan (typically a mortgage), based on the amortization process.
The amortization repayment model factors varying amounts of both interest and principal into every installment, though the total amount of each payment is the same.
An amortization schedule calculator is often used to adjust the loan amount until the monthly payments will fit comfortably into budget, and can vary the interest rate to see the difference a better rate might make in the kind of home or car one can afford. An amortization calculator can also reveal the exact dollar amount that goes towards interest and the exact dollar amount that goes towards principal out of each individual payment. The amortization schedule is a table delineating these figures across the duration of the loan in chronological order.
The formula
The calculation used to arrive at the periodic payment amount assumes that the first payment is not due on the first day of the loan, but rather one full payment period into the loan.
While normally used to solve for A, (the payment, given the terms) it can be used to solve for any single variable in the equation provided that all other variables are known. One can rearrange the formula to solve for any one term, except for i, for which one can use a root-finding algorithm.
The annuity formula is:
Or, equivalently:
Where:
A = periodic payment amount
P = amount of principal, net of initial payments, meaning "subtract any down-payments"
i = periodic interest rate
n = total number of payments
This formula is valid if i > 0. If i = 0 then simply A = P / n.
For a 30-year loan with monthly payments,
Note that the interest rate is commonly referred to as an annual percentage rate (e.g. 8% APR), but in the above formula, since the payments are monthly, the rate must be in terms of a monthly percent. Converting an annual interest rate (that is to say, annual percentage yield or APY) to the m
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https://en.wikipedia.org/wiki/Process%20function
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In thermodynamics, a quantity that is well defined so as to describe the path of a process through the equilibrium state space of a thermodynamic system is termed a process function, or, alternatively, a process quantity, or a path function. As an example, mechanical work and heat are process functions because they describe quantitatively the transition between equilibrium states of a thermodynamic system.
Path functions depend on the path taken to reach one state from another. Different routes give different quantities. Examples of path functions include work, heat and arc length. In contrast to path functions, state functions are independent of the path taken. Thermodynamic state variables are point functions, differing from path functions. For a given state, considered as a point, there is a definite value for each state variable and state function.
Infinitesimal changes in a process function are often indicated by to distinguish them from infinitesimal changes in a state function which is written . The quantity is an exact differential, while is not, it is an inexact differential. Infinitesimal changes in a process function may be integrated, but the integral between two states depends on the particular path taken between the two states, whereas the integral of a state function is simply the difference of the state functions at the two points, independent of the path taken.
In general, a process function may be either holonomic or non-holonomic. For a holonomic process function, an auxiliary state function (or integrating factor) may be defined such that is a state function. For a non-holonomic process function, no such function may be defined. In other words, for a holonomic process function, may be defined such that is an exact differential. For example, thermodynamic work is a holonomic process function since the integrating factor (where is pressure) will yield exact differential of the volume state function . The second law of thermodynamics
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https://en.wikipedia.org/wiki/Coulomb%20operator
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The Coulomb operator, named after Charles-Augustin de Coulomb, is a quantum mechanical operator used in the field of quantum chemistry. Specifically, it is a term found in the Fock operator. It is defined as:
where
is the one-electron Coulomb operator defining the repulsion resulting from electron j,
is the one-electron wavefunction of the electron being acted upon by the Coulomb operator,
is the one-electron wavefunction of the electron,
is the distance between electrons and .
See also
Core Hamiltonian
Exchange operator
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https://en.wikipedia.org/wiki/Exchange%20operator
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In quantum mechanics, the exchange operator , also known as permutation operator, is a quantum mechanical operator that acts on states in Fock space. The exchange operator acts by switching the labels on any two identical particles described by the joint position quantum state . Since the particles are identical, the notion of exchange symmetry requires that the exchange operator be unitary.
Construction
In three or higher dimensions, the exchange operator can represent a literal exchange of the positions of the pair of particles by motion of the particles in an adiabatic process, with all other particles held fixed. Such motion is often not carried out in practice. Rather, the operation is treated as a "what if" similar to a parity inversion or time reversal operation. Consider two repeated operations of such a particle exchange:
Therefore, is not only unitary but also an operator square root of 1, which leaves the possibilities
Both signs are realized in nature. Particles satisfying the case of +1 are called bosons, and particles satisfying the case of −1 are called fermions. The spin–statistics theorem dictates that all particles with integer spin are bosons whereas all particles with half-integer spin are fermions.
The exchange operator commutes with the Hamiltonian and is therefore a conserved quantity. Therefore, it is always possible and usually most convenient to choose a basis in which the states are eigenstates of the exchange operator. Such a state is either completely symmetric under exchange of all identical bosons or completely antisymmetric under exchange of all identical fermions of the system. To do so for fermions, for example, the antisymmetrizer builds such a completely antisymmetric state.
In 2 dimensions, the adiabatic exchange of particles is not necessarily possible. Instead, the eigenvalues of the exchange operator may be complex phase factors (in which case is not Hermitian), see anyon for this case. The exchange operato
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https://en.wikipedia.org/wiki/Miller%20effect
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In electronics, the Miller effect accounts for the increase in the equivalent input capacitance of an inverting voltage amplifier due to amplification of the effect of capacitance between the input and output terminals. The virtually increased input capacitance due to the Miller effect is given by
where is the voltage gain of the inverting amplifier ( positive) and is the feedback capacitance.
Although the term Miller effect normally refers to capacitance, any impedance connected between the input and another node exhibiting gain can modify the amplifier input impedance via this effect. These properties of the Miller effect are generalized in the Miller theorem. The Miller capacitance due to parasitic capacitance between the output and input of active devices like transistors and vacuum tubes is a major factor limiting their gain at high frequencies. Miller capacitance was identified in 1920 in triode vacuum tubes by John Milton Miller.
History
The Miller effect was named after John Milton Miller. When Miller published his work in 1920, he was working on vacuum tube triodes. The same analysis applies to modern devices such as bipolar junction and field-effect transistors.
Derivation
Consider an ideal inverting voltage amplifier of gain with an impedance connected between its input and output nodes. The output voltage is therefore . Assuming that the amplifier input draws no current, all of the input current flows through , and is therefore given by
.
The input impedance of the circuit is
.
If represents a capacitor with impedance , the resulting input impedance is
.
Thus the effective or Miller capacitance CM is the physical C multiplied by the factor .
Effects
As most amplifiers are inverting ( as defined above is positive), the effective capacitance at their inputs is increased due to the Miller effect. This can reduce the bandwidth of the amplifier, restricting its range of operation to lower frequencies. The tiny junction and stray capaci
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https://en.wikipedia.org/wiki/Candidatus%20Brocadia%20anammoxidans
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"Candidatus Brocadia anammoxidans" is a bacterial member of the phylum Planctomycetota and therefore lacks peptidoglycan in its cell wall, and has a compartmentalized cytoplasm.
"Candidatus Brocadia anammoxidans" was the first discovered organism capable of the anaerobic oxidation of ammonium, and it is the only organism known to produce hydrazine. This process (dubbed the anammox-process) was discovered in the 1980s by the Gijs Kuenen lab in a waste water treatment plant in Delft, Netherlands. Ammonium oxidation is coupled to nitrite reduction to form the harmless dinitrogen gas.
The key enzyme involved in this reaction, hydroxylamine oxidoreductase, is located in an organelle-like structure called the anammoxosome. The ability to oxidize ammonium anaerobically makes "Candidatus Brocadia anammoxidans" potentially useful for reducing—or eliminating—ammonium from waste water.
In waste treatment
Because of its ability to eliminate ammonium, a variety of uses have been found for this bacteria, particularly removal of nitrogen from waste streams. The first full scale experiment employing the anammox process in the world was built in 2010 at the waste water treatment plant Dokhaven/Sluisjesdijk in Rotterdam, Netherlands.
Existing treatment plants use bacteria that convert ammonium into nitrate. The bacteria that do this need oxygen, which must be supplied by electric pumps. Denitrifying bacteria convert the nitrate into nitrogen gas. These require adding methanol. This process consumes an average of 44 watt-hours per day per person served by the sewage system.
Researchers estimate that a methanogenic digester coupled to a nitrification-anammox bioreactor could generate 24 watt-hours per person per day, a net swing of 70 watt-hours.
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https://en.wikipedia.org/wiki/Sodium%20oxybate
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Sodium oxybate, sold under the brand name Xyrem among others, is a medication used to treat symptoms of narcolepsy: sudden muscle weakness and excessive daytime sleepiness. It is used sometimes in France and Italy as an anesthetic given intravenously; it is also approved and used in Italy and in Austria to treat alcohol dependence and alcohol withdrawal syndrome.
Sodium oxybate is the sodium salt of γ-hydroxybutyric acid (GHB). The clinical trials for narcolepsy were conducted just as abuse of GHB as a club drug and date rape drug became a matter of public concern; in 2000 GHB was made a Schedule I controlled substance, while sodium oxybate, when used under an FDA NDA or IND application, was classified as a Schedule III controlled substance for medicinal use under the Controlled Substances Act, with illicit use subject to Schedule I penalties.
Sodium oxybate was approved for use by the US Food and Drug Administration (FDA) to treat symptoms of narcolepsy in 2002, with a strict risk evaluation and mitigation strategy (REMS) program mandated by the FDA. The US label for sodium oxybate also has a black box warning because it is a central nervous system depressant and may cause respiratory depression, seizures, coma, or death, especially if used in combination with other central nervous system depressants, such as alcohol and its use may cause dependence. In Canada and the European Union it was classified as a Schedule III and a Schedule IV controlled substance, respectively.
It was approved for treating symptoms of narcolepsy in the European Union in 2005.
Orphan Medical had developed it and was acquired by Jazz Pharmaceuticals in 2005. The drug is marketed in Europe by UCB. Jazz Pharmaceuticals raised the price of the drug dramatically after it acquired Orphan, and paid a $20M fine for off-label marketing of the drug in 2007.
Medical use
Clinical use of sodium oxybate was introduced in Europe in 1964, as anesthetic given intravenously but it was not widely used s
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https://en.wikipedia.org/wiki/International%20Prize%20for%20Biology
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The is an annual award for "outstanding contribution to the advancement of research in fundamental biology." The Prize, although it is not always awarded to a biologist, is one of the most prestigious honours a natural scientist can receive. There are no restrictions on the nationality of the recipient.
Past laureates include John B. Gurdon, Motoo Kimura, Edward O. Wilson, Ernst Mayr, Thomas Cavalier-Smith, Yoshinori Ohsumi and many other great biologists in the world.
Information
The International Prize of Biology was created in 1985 to commemorate the 60-year reign of Emperor Shōwa of Japan and his longtime interest in and support of biology. The selection and award of the prize is managed by the Japan Society for the Promotion of Science. The laureate is awarded a beautiful medal, 10 million yen, and an international symposium on the scientist's area of research is held in Tokyo. The prize ceremony is held in the presence of Emperor of Japan.
The first International Prize for Biology was awarded to E. J. H. Corner, who was a prominent scientist in the field of systematic biology, because Emperor Shōwa was interested in and worked on this field for long time.
Criteria
The Prize is awarded in accordance with the following criteria:
The Prize shall be made by the Committee every year, commencing in 1985.
The Prize shall consist of a medal and a prize of ten million (10,000,000) yen.
There shall be no restrictions on the nationality of the recipient.
The Prize shall be awarded to an individual who, in the judgment of the members of the Committee, has made an outstanding contribution to the advancement of research in fundamental biology.
The specialty within the field of biology for which the Prize will be awarded shall be decided upon annually by the Committee.
The Committee shall be advised on suitable candidates for the Prize by a selection committee, which will consist of Japanese and overseas members.
The selection committee shall invite nominations of can
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https://en.wikipedia.org/wiki/Codec%20listening%20test
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A codec listening test is a scientific study designed to compare two or more lossy audio codecs, usually with respect to perceived fidelity or compression efficiency.
Most tests take the form of a double-blind comparison. Commonly used methods are known as "ABX" or "ABC/HR" or "MUSHRA". There are various software packages available for individuals to perform this type of testing themselves with minimal assistance.
Testing methods
ABX test
In an ABX test, the listener has to identify an unknown sample X as being A or B, with A (usually the original) and B (usually the encoded version) available for reference. The outcome of a test must be statistically significant. This setup ensures that the listener is not biased by their expectations, and that the outcome is not likely to be the result of chance. If sample X cannot be determined reliably with a low p-value in a predetermined number of trials, then the null hypothesis cannot be rejected and it cannot be proved that there is a perceptible difference between samples A and B. This usually indicates that the encoded version will actually be transparent to the listener.
ABC/HR test
In an ABC/HR test, C is the original which is always available for reference. A and B are the original and the encoded version in randomized order. The listener must first distinguish the encoded version from the original (which is the Hidden Reference that the "HR" in ABC/HR stands for), prior to assigning a score as a subjective judgment of the quality. Different encoded versions can be compared against each other using these scores.
MUSHRA
In MUSHRA (MUltiple Stimuli with Hidden Reference and Anchor), the listener is presented with the reference (labeled as such), a certain number of test samples, a hidden version of the reference and one or more anchors. The purpose of the anchor(s) is to make the scale be closer to an "absolute scale", making sure that minor artifacts are not rated as having very bad quality.
Results
M
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https://en.wikipedia.org/wiki/Blue%20hour
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The blue hour (from French ; ) is the period of twilight (in the morning or evening, around the nautical stage) when the Sun is at a significant depth below the horizon. During this time, the remaining sunlight takes on a mostly blue shade. This shade differs from the colour of the sky on a clear day, which is caused by Rayleigh scattering.
The blue hour occurs when the Sun is far enough below the horizon so that the sunlight's blue wavelengths dominate due to the Chappuis absorption caused by ozone. Since the term is colloquial, it lacks an official definition such as dawn, dusk, or the three stages of twilight. Rather, blue hour refers to the state of natural lighting that usually occurs around the nautical stage of the twilight period (at dawn or dusk).
Explanation and times of occurrence
The still commonly presented incorrect explanation claims that Earth's post-sunset and pre-sunrise atmosphere solely receives and disperses the sun's shorter blue wavelengths and scatters the longer, reddish wavelengths to explain why the hue of this hour is so blue. In fact, the blue hour occurs when the Sun is far enough below the horizon so that the sunlight's blue wavelengths dominate due to the Chappuis absorption caused by ozone.
When the sky is clear, the blue hour can be a colourful spectacle, with the indirect sunlight tinting the sky yellow, orange, red, and blue. This effect is caused by the relative diffusibility of shorter wavelengths (bluer rays) of visible light versus the longer wavelengths (redder rays). During the blue "hour", red light passes through space while blue light is scattered in the atmosphere, and thus reaches Earth's surface.
Blue hour usually lasts about 20–96 minutes right after sunset and right before sunrise. Time of year, location, and air quality all have an impact on the exact timing of blue hour. For instance in Egypt (every 21st of June), when sunset is at 7:59 PM: blue hour occurs from 7:59 PM to 9:35 PM. When sunrise is at 5:54 AM: b
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https://en.wikipedia.org/wiki/Switch56
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Nortel's Switch56 was a networking protocol built on top of the telephone cabling hardware of their Digital Multiplex System and other telephone switches.
The name comes from the fact that Switch56 carried 56 kbit/s of data on its 64 kbit/s lines, as opposed to most systems, including ISDN, where the entire 64 kbit/s bandwidth was available for data. The speed was a side effect of Nortel using a 2-wire cable to carry both voice and switching commands, as opposed to other systems where the command data was carried on a separate set of low-speed lines. Switch56 "folded" the two sources of data into one, placing a single bit from the command channel onto the end of every 7 bits of data, similar to the original T-carrier supervision scheme. This data was split out at the "far end" as 56 kbit/s and 8 kbit/s subchannels.
Switch56 was built on top of the basic Nortel hardware to allow computers to put data into the existing telephony network. Although slow compared to even contemporary systems, Switch56 allowed network traffic to flow not only within an office like other LAN systems, but between any branch offices that were connected using a Nortel PBX like the Meridian Norstar. This was a much easier option to install than ISDN for most offices, requiring nothing more than a Switch56 bridge to their existing network. For the LAN role new telephone terminals were produced with a RS-232C port on the back, which were then plugged into the user's computer and used with custom software. Although interesting in theory, it appears Switch56 saw little use in this role.
Network protocols
Telephone exchange equipment
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https://en.wikipedia.org/wiki/Food%20and%20Allied%20Workers%20Union
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The Food and Allied Workers Union (FAWU) is a trade union representing workers in the food processing industry in South Africa.
The union was formed in 1986, through the amalgamation of the Food and Canning Workers' Union, the Sweet, Food and Allied Workers' Union and the Retail and Allied Workers' Union. In 2004, the union absorbed the South African Agricultural Plantation and Allied Workers Union.
The union was long affiliated to the Congress of South African Trade Unions, but it resigned in 2016, in protest at the expulsion of the National Union of Metalworkers of South Africa (NUMSA).
In 2017, it was a founding affiliate of the South African Federation of Trade Unions (SAFTU), becoming that federation's second largest affiliate.
Leadership
General Secretaries
1986: Mike Madlala
1986: Jan Theron
1988: Mandla Gxanyana
2004: Katishi Masemola
2020: Mayoyo Mngomezulu
Presidents
1986: Chris Dlamini
1990s: E. Theron
Phillip Khage
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https://en.wikipedia.org/wiki/Eicon
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Eicon Networks Corporation, formerly Eicon Technology Corporation, is a privately owned designer, developer and manufacturer of communication products founded on October 12, 1984 with headquarters in Montreal, Quebec, Canada. Eicon products are sold worldwide through a large network of distributors and resellers, and supplied to OEMs.
In October 2006, Eicon purchased the Media & Signalling Division of Intel, known as Dialogic before its purchase by Intel in 1999, which produces telephony boards for PC servers. The combined Eicon/Dialogic company changed its name to Dialogic Corporation at the time of the purchase. It is meanwhile known as Dialogic Inc.
Products
Eicon's products include the Diva Family (Diva Server and Diva Client) and Eiconcard product lines.
Diva Server
Diva Server is a range of telecoms products for voice, speech, conferencing and fax. It supports T1/E1; SS7; ISDN and conventional phone line (PSTN). As of 2008 Eicon Host Media Processing products, "software adapters" that provide VoIP capability for applications, are available.
Diva Server is used in VoiceXML speech servers; SMS gateways; fax and unified messaging and call recording and monitoring.
Diva Client
Diva products are connectivity products for remote access for the home and for remote and mobile workers. They are mostly ISDN or combined ISDN and dialup modems. In the past Eicon produced ADSL and Wi-Fi equipment, but these areas have become dominated by far-eastern manufacturers.
Eiconcard
The Eiconcard connects legacy X.25 systems for tasks such as credit card authorization, SMS, and satellite communications. The Eiconcard has been produced since the company was founded in 1984, and continues to be available.
Eicon cards with their flexible protocol stacks were also used as a flexible communications gateway to IBM's midrange and mainframe computers and for a time occupied a niche market allowing Ethernet based PC networks to utilise IBM's LU6.2 (intelligent) communications rou
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https://en.wikipedia.org/wiki/Density%20on%20a%20manifold
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In mathematics, and specifically differential geometry, a density is a spatially varying quantity on a differentiable manifold that can be integrated in an intrinsic manner. Abstractly, a density is a section of a certain line bundle, called the density bundle. An element of the density bundle at x is a function that assigns a volume for the parallelotope spanned by the n given tangent vectors at x.
From the operational point of view, a density is a collection of functions on coordinate charts which become multiplied by the absolute value of the Jacobian determinant in the change of coordinates. Densities can be generalized into s-densities, whose coordinate representations become multiplied by the s-th power of the absolute value of the jacobian determinant. On an oriented manifold, 1-densities can be canonically identified with the n-forms on M. On non-orientable manifolds this identification cannot be made, since the density bundle is the tensor product of the orientation bundle of M and the n-th exterior product bundle of TM (see pseudotensor).
Motivation (densities in vector spaces)
In general, there does not exist a natural concept of a "volume" for a parallelotope generated by vectors in a n-dimensional vector space V. However, if one wishes to define a function that assigns a volume for any such parallelotope, it should satisfy the following properties:
If any of the vectors vk is multiplied by , the volume should be multiplied by |λ|.
If any linear combination of the vectors v1, ..., vj−1, vj+1, ..., vn is added to the vector vj, the volume should stay invariant.
These conditions are equivalent to the statement that μ is given by a translation-invariant measure on V, and they can be rephrased as
Any such mapping is called a density on the vector space V. Note that if (v1, ..., vn) is any basis for V, then fixing μ(v1, ..., vn) will fix μ entirely; it follows that the set Vol(V) of all densities on V forms a one-dimensional vector space. Any n-f
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https://en.wikipedia.org/wiki/Noreen
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Noreen, or BID 590, was an off-line one-time tape cipher machine of British origin.
Usage
As well as being used by the United Kingdom, Noreen was used by Canada. It was widely used in diplomatic stations. According to the display note on a surviving unit publicly displayed at Bletchley Park in the United Kingdom, the system was predominantly used "by the foreign office in British embassies overseas where the electricity supply was unreliable."
Usage lasted from the mid-1960s through 1990.
Compatibility
It was completely compatible with Rockex.
Power Supply
The units were powered by two batteries of six and twelve volts respectively, though some were known to have been powered by mains.
Other uses of the name "Noreen"
Noreen was the name of a wooden dragger that was acquired by the U.S. Navy during World War II and converted into the minesweeper USS Heath Hen (AMc-6).
Noreen is a common name in the Americas, Ireland, Scotland, and the Middle East. Also spelt Naureen, Noirin and Nowrin (نورين). In Arabic, the word means "luminous"'. In Ireland and Scotland, 'Noreen' is the anglicized version of 'Nóirín', which is the diminutive of 'Nora'.
External links
Jerry Proc's page on Noreen
Noreen on Crypto Museum website
Noreen
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https://en.wikipedia.org/wiki/Storm%20Water%20Management%20Model
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The United States Environmental Protection Agency (EPA) Storm Water Management Model (SWMM) is a dynamic rainfall–runoff–subsurface runoff simulation model used for single-event to long-term (continuous) simulation of the surface/subsurface hydrology quantity and quality from primarily urban/suburban areas. It can simulate the Rainfall- runoff, runoff, evaporation, infiltration and groundwater connection for roots, streets, grassed areas, rain gardens and ditches and pipes, for example. The hydrology component of SWMM operates on a collection of subcatchment areas divided into impervious and pervious areas with and without depression storage to predict runoff and pollutant loads from precipitation, evaporation and infiltration losses from each of the subcatchment. Besides, low impact development (LID) and best management practice areas on the subcatchment can be modeled to reduce the impervious and pervious runoff. The routing or hydraulics section of SWMM transports this water and possible associated water quality constituents through a system of closed pipes, open channels, storage/treatment devices, ponds, storages, pumps, orifices, weirs, outlets, outfalls and other regulators.
SWMM tracks the quantity and quality of the flow generated within each subcatchment, and the flow rate, flow depth, and quality of water in each pipe and channel during a simulation period composed of multiple fixed or variable time steps. The water quality constituents such as water quality constituents can be simulated from buildup on the subcatchments through washoff to a hydraulic network with optional first order decay and linked pollutant removal, best management practice and low-impact development (LID) removal and treatment can be simulated at selected storage nodes. SWMM is one of the hydrology transport models which the EPA and other agencies have applied widely throughout North America and through consultants and universities throughout the world. The latest update notes and n
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https://en.wikipedia.org/wiki/NetBoot
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NetBoot was a technology from Apple which enabled Macs with capable firmware (i.e. New World ROM) to boot from a network, rather than a local hard disk or optical disc drive. NetBoot is a derived work from the Bootstrap Protocol (BOOTP), and is similar in concept to the Preboot Execution Environment. The technology was announced as a part of the original version of Mac OS X Server at Macworld Expo on 5 January 1999. NetBoot has continued to be a core systems management technology for Apple, and has been adapted to support modern Mac Intel machines. NetBoot, USB, and FireWire are some of the external volume options for operating system re-install. NetBoot is not supported on newer Macs with T2 security chip or Apple silicon.
Process
A disk image with a copy of macOS, macOS Server, Mac OS 9, or Mac OS 8 is created using System Image Utility and is stored on a server, typically macOS Server. Clients receive this image across a network using many popular protocols including: HTTPS, AFP, TFTP, NFS, and multicast Apple Software Restore (ASR). Server-side NetBoot image can boot entire machines, although NetBoot is more commonly used for operating system and software deployment, somewhat similar to Norton Ghost.
Client machines first request network configuration information through DHCP, then a list of boot images and servers with BSDP and then proceed to download images with protocols mentioned above.
Both Intel and PowerPC-based servers can serve images for Intel and PowerPC-based clients.
NetInstall
NetInstall is a similar feature of macOS Server which utilizes NetBoot and ASR to deliver installation images to network clients (typically on first boot). Like NetBoot, NetInstall images can be created using the System Image Utility. NetInstall performs a function for macOS similar to Windows Deployment Services for Microsoft clients, which depend on the Preboot Execution Environment.
Legacy
Mac OS 8.5 and Mac OS 9 use only BOOTP/DHCP to get IP information, followed
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https://en.wikipedia.org/wiki/Shunting%20%28neurophysiology%29
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Shunting is an event in the neuron which occurs when an excitatory postsynaptic potential and an inhibitory postsynaptic potential are occurring close to each other on a dendrite, or are both on the soma of the cell.
According to temporal summation one would expect the inhibitory and excitatory currents to be summed linearly to describe the resulting current entering the cell. However, when inhibitory and excitatory currents are on the soma of the cell, the inhibitory current causes the cell resistance to change (making the cell "leakier"), thereby "shunting" instead of completely eliminating the effects of the excitatory input.
See also
Spatial summation
Temporal summation
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https://en.wikipedia.org/wiki/Calculus%20of%20voting
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Calculus of voting refers to any mathematical model which predicts voting behaviour by an electorate, including such features as participation rate. A calculus of voting represents a hypothesized decision-making process.
These models are used in political science in an attempt to capture the relative importance of various factors influencing an elector to vote (or not vote) in a particular way.
Example
One such model was proposed by Anthony Downs (1957) and is adapted by William H. Riker and Peter Ordeshook, in “A Theory of the Calculus of Voting” (Riker and Ordeshook 1968)
V = pB − C + D
where
V = the proxy for the probability that the voter will turn out
p = probability of vote “mattering”
B = “utility” benefit of voting--differential benefit of one candidate winning over the other
C = costs of voting (time/effort spent)
D = citizen duty, goodwill feeling, psychological and civic benefit of voting (this term is not included in Downs's original model)
A political science model based on rational choice used to explain why citizens do or do not vote.
The alternative equation is
V = pB + D > C
Where for voting to occur the (P)robability the vote will matter "times" the (B)enefit of one candidate winning over another combined with the feeling of civic (D)uty, must be greater than the (C)ost of voting
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https://en.wikipedia.org/wiki/Circuit%20extraction
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The electric circuit extraction or simply circuit extraction, also netlist extraction, is the translation of an integrated circuit layout back into the electrical circuit (netlist) it is intended to represent. This extracted circuit is needed for various purposes including circuit simulation, static timing analysis, signal integrity, power analysis and optimization, and logic to layout comparison. Each of these functions require a slightly different representation of the circuit, resulting in the need for multiple layout extractions. In addition, there may be a postprocessing step of converting the device-level circuit into a purely digital circuit, but this is not considered part of the extraction process.
The detailed functionality of an extraction process will depend on its system environment. The simplest form of extracted circuit may be in the form of a netlist, which is formatted for a particular simulator or analysis program. A more complex extraction may involve writing the extracted circuit back into the original database containing the physical layout and the logic diagram. In this case, by associating the extracted circuit with the layout and the logic network, the user can cross-reference any point in the circuit to its equivalent points in the logic and layout (cross-probing). For simulation or analysis, various formats of netlist can then be generated using programs that read the database and generate the appropriate text information.
In extraction, it is often helpful to make an (informal) distinction between designed devices, which are devices that are deliberately created by the designer, and parasitic devices, which were not explicitly intended by the designer but are inherent in the layout of the circuit.
Primarily there are three different parts to the extraction process. These are designed device extraction, interconnect extraction, and parasitic device extraction. These parts are inter-related since various device extractions can change th
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https://en.wikipedia.org/wiki/Aorta-gonad-mesonephros
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The aorta-gonad-mesonephros (AGM) is a region of embryonic mesoderm that develops during embryonic development from the para-aortic splanchnopleura in chick, mouse and human embryos. The very first adult definitive haematopoietic stem cells, capable of long-term multilineage repopulation of adult irradiated recipients, originate from the ventral endothelial wall of the embryonic dorsal aorta, through an endothelial transdifferentiation process referred to as an 'endothelial-to-haematopoietic transition' (EHT). In the mouse embryo, these very first HSCs are characterised by their expression of Ly6A-GFP (Sca1), CD31, CD34, cKit, CD27, CD41, Gata2, Runx1, Notch1, and BMP amongst others.
The aorta-gonad-mesonephros (AGM) region is an area derived from splanchnopleura mesoderm identified in embryonic humans, mice, and non-mammalian vertebrates such as birds and zebrafish. It contains the dorsal aorta, genital ridges and mesonephros and lies between the notochord and the somatic mesoderm, extending from the umbilicus to the anterior limb bud of the embryo. The AGM region plays an important role in embryonic development, being the first autonomous intra-embryonic site for definitive haematopoiesis. Definitive haematopoiesis produces haematopoietic stem cells that have the capacity to 'self-renew' when serially transplanted into irradiated recipients, and differentiate into any of the blood cell lineages of the adult haematopoietic hierarchy. Specialised endothelial cells in the floor of the dorsal aorta (within the AGM region), identified as haemogenic endothelium, differentiate into haematopoietic stem cells.
In embryonic development
The AGM region is derived from the mesoderm layer of the embryo. During organogenesis (around the fourth week in human embryos), the visceral region of the mesoderm, the splanchnopleura, transforms into distinct structures consisting of the dorsal aorta, genital ridges and mesonephros. For a period during embryonic development, the dors
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https://en.wikipedia.org/wiki/Multiton%20pattern
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In software engineering, the multiton pattern is a design pattern which generalizes the singleton pattern. Whereas the singleton allows only one instance of a class to be created, the multiton pattern allows for the controlled creation of multiple instances, which it manages through the use of a map.
Rather than having a single instance per application (e.g. the object in the Java programming language) the multiton pattern instead ensures a single instance per key.
The multiton pattern does not explicitly appear as a pattern in the highly regarded object-oriented programming textbook Design Patterns. However, the book describes using a registry of singletons to allow subclassing of singletons, which is essentially the multiton pattern.
Description
While it may appear that the multiton is a hash table with synchronized access there are two important distinctions. First, the multiton does not allow clients to add mappings. Secondly, the multiton never returns a null or empty reference; instead, it creates and stores a multiton instance on the first request with the associated key. Subsequent requests with the same key return the original instance. A hash table is merely an implementation detail and not the only possible approach. The pattern simplifies retrieval of shared objects in an application.
Since the object pool is created only once, being a member associated with the class (instead of the instance), the multiton retains its flat behavior rather than evolving into a tree structure.
The multiton is unique in that it provides centralized access to a single directory (i.e. all keys are in the same namespace, per se) of multitons, where each multiton instance in the pool may exist having its own state. In this manner, the pattern advocates indexed storage of essential objects for the system (such as would be provided by an LDAP system, for example). However, a multiton is limited to wide use by a single system rather than a myriad of distributed system
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https://en.wikipedia.org/wiki/Vapor%20pressure%20osmometry
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Vapor phase osmometry (VPO), also known as vapor-pressure osmometry, is an experimental technique for the determination of a polymer's number average molecular weight, Mn. It works by taking advantage of the decrease in vapor pressure that occurs when solutes are added to pure solvent. This technique can be used for polymers with a molecular weight of up to 20,000 though accuracy is best for those below 10,000. Although membrane osmometry is also based on the measurement of colligative properties, it has a lower bound of 25,000 for sample molecular weight that can be measured owing to problems with membrane permeation.
Experiment
A typical vapor phase osmometer consists of: (1) two thermistors, one with a polymer-solvent solution droplet adhered to it and another with a pure solvent droplet adhered to it; (2) a thermostatted chamber with an interior saturated with solvent vapor; (3) a liquid solvent vessel in the chamber; and (4) an electric circuit to measure the bridge output imbalance difference between the two thermistors. The voltage difference is an accurate way of measuring the temperature difference between the two thermistors, which is a consequence of solvent vapor condensing on the solution droplet (the solution droplet has a lower vapor pressure than the solvent).
Mn Calculation and Calibration
The number average molecular weight for a polymer sample is given by the following equation:
where:
is a calibration constant,
is the bridge imbalance output voltage,
is the polymer-solvent solution concentration
It is necessary to calibrate a vapor phase osmometer and it is important to note that K is found for a particular solvent, operational temperature, and type of commercial apparatus. A calibration can be carried out using a standard of known molecular weight. Some possible solvents for VPO include toluene, tetrahydrofuran, or chloroform. Once the experiment is performed, concentration and output voltage data can be graphed on a plot of (ΔV/c) vers
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https://en.wikipedia.org/wiki/Zero%20force%20member
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In the field of engineering mechanics, a zero force member is a member (a single truss segment) in a truss which, given a specific load, is at rest: neither in tension, nor in compression.
Description
In a truss, a zero force member is often found at pins (any connections within the truss) where no external load is applied, and three or fewer truss members meet. Identification of basic zero force members can be accomplished by analyzing the forces acting on an individual pin in a physical system.
If the pin has an external force or moment applied to it, then all of the members attached to that pin are not zero force members unless the external force acts in a manner that fulfills one of the rules below:
If two non-collinear members meet in an unloaded joint, both are zero-force members.
If three members meet in an unloaded joint of which two are collinear, then the third member is a zero-force member.
Reasons to include zero force members in a truss system
It is a common practice to eliminate zero force members from a truss, to simplify analysis. Although an absolute minimalist design might eliminate all zero force elements from a truss, there are still sound reasons to retain some of these components in actual built systems:
These members can contribute to the stability of the structure, by preventing buckling of long slender members under compressive forces
These members can increase rigidity when variations are introduced in the normal external loading configuration, including dynamic and variable forces.
See also
Structural engineering
Neutral plane
External links
Truss Overview
Another Truss Overview
Sources
Engineering Mechanics Volume 1: Equilibrium, by C. Hartsuijker and J.W. Welleman
Structural analysis
Statics
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https://en.wikipedia.org/wiki/Academy%20ratio
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The Academy ratio of 1.375:1 (abbreviated as 1.37:1) is an aspect ratio of a frame of 35 mm film when used with 4-perf pulldown. It was standardized by the Academy of Motion Picture Arts and Sciences as the standard film aspect ratio in 1932, although similar-sized ratios were used as early as 1928.
History
Silent films were shot at a 1.3 aspect ratio (also known as a 4:3 aspect ratio), with each frame using all of the negative space between the two rows of film perforations for a length of 4 perforations. The frame line between the silent film frames was very thin. When sound-on-film was introduced in the late 1920s, the soundtrack was recorded in a stripe running just inside one set of the perforations and cut into the 1.33 image. This made the image area "taller", usually around 1.19, which was slightly disorienting to audiences used to the 1.3 frame and also presented problems for exhibitors with fixed-size screens and stationary projectors.
From studio to studio, the common attempt to reduce the image back to a 1.3:1 ratio by decreasing the projector aperture in-house met with conflicting results. Each movie theater chain, furthermore, had its own designated house ratio. The first standards set for the new sound-on-film motion pictures were accepted in November 1929, when all major US studios agreed to compose for the Society of Motion Picture and Television Engineers (SMPE) designated size of returning to the aspect ratio of 1.3:1.
Following this, Academy of Motion Picture Arts and Sciences (AMPAS) considered further alterations to this 1930 standard. Various dimensions were submitted, and the projector aperture plate opening size of 0.825 in × 0.600 in was agreed upon. The resulting 1.375:1 aspect ratio was then dubbed the "Academy Ratio". On May 9, 1932, the SMPE adopted the same projector aperture standard.
All studio films shot in 35 mm from 1932 to 1952 were shot in the Academy ratio. However, following the widescreen "revolution" of 1953, it q
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https://en.wikipedia.org/wiki/WTVJ
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WTVJ (channel 6) is a television station in Miami, Florida, United States, serving as the market's NBC outlet. It is owned and operated by the network's NBC Owned Television Stations division alongside Fort Lauderdale–licensed WSCV (channel 51), a flagship station of Telemundo. Both stations share studios on Southwest 27th Street in Miramar, while WTVJ's transmitter is located in Andover, Florida.
History
Florida's first television station
The station first signed on the air on March 21, 1949, at 12:00 p.m. WTVJ was the first television station to sign on in the state of Florida, and the 16th station in the United States. Originally broadcasting on VHF channel 4, the station was founded by Wometco Enterprises (founded by Mitchell Wolfson and Sidney Meyer), a national movie theater chain that was headquartered in Miami. The station's original studio facilities were located in the former Capitol Theater on North Miami Avenue in Downtown Miami, which was the first theater operated by Wometco when the company was founded in 1926. The station was a primary CBS affiliate, but also carried programming from the other three major broadcast networks of that era (ABC, NBC and DuMont). During the late 1950s, the station was also briefly affiliated with the NTA Film Network.
WTVJ was the only commercial television station in the Miami market until Fort Lauderdale-based WFTL-TV (channel 23) signed on the air on December 24, 1954, operating as an NBC affiliate. However, WFTL had no success whatsoever in competing against WTVJ, in part because television sets were not required to have UHF tuning capability until the All-Channel Receiver Act went into effect in 1964. NBC continued to allow WTVJ to cherry-pick programs broadcast by the network until WCKT (channel 7, now Fox affiliate WSVN) signed on in July 1956 and WFTL went dark (that station's former channel 23 allocation is now occupied by Univision owned-and-operated station WLTV-DT). Channel 4 shared ABC programming with WC
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https://en.wikipedia.org/wiki/Tom%20W.%20Bonner%20Prize
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The Tom W. Bonner Prize in Nuclear Physics is an annual prize awarded by the American Physical Society's Division of Nuclear Physics. Established in 1964, and currently consisting of $10,000 and a certificate, the Bonner Prize was founded in memory of physicist Tom W. Bonner. The aim of the prize, as stated by the American Physical Society is:
To recognize and encourage outstanding experimental research in nuclear physics, including the development of a method, technique, or device that significantly contributes in a general way to nuclear physics research.
The Bonner Prize is generally awarded for individual achievement in experimental research, but can be awarded for exceptional theoretical work and to groups who have contributed to a single accomplishment.
Recipients
See also
List of physics awards
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https://en.wikipedia.org/wiki/WPCH-TV
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WPCH-TV (channel 17), branded on-air as Peachtree TV, is a television station in Atlanta, Georgia, United States, affiliated with The CW. It is owned by locally based Gray Television alongside CBS affiliate and company flagship WANF (channel 46), and low-power, Class A Telemundo affiliate WKTB-CD (channel 47). WPCH-TV and WANF share studios on 14th Street Northwest in Atlanta's Home Park neighborhood, while WPCH-TV's transmitter is located in the Woodland Hills section of northeastern Atlanta.
During its ownership under the Turner Broadcasting System (which owned the station from April 1970 until February 2017), WPCH-TV—then using the WTCG call letters—pioneered the distribution of broadcast television stations retransmitted by communications satellite to cable and satellite subscribers throughout the United States, expanding the small independent station into the first national "superstation" on December 17, 1976. (The station eventually became among the first four American superstations to begin being distributed to television providers in Canada in 1985.)
The former superstation feed—which eventually became known as simply TBS, and had maintained a nearly identical program schedule as the local Atlanta feed—was converted by Turner into a conventional basic cable network on October 1, 2007, at which time it was concurrently added to cable providers within the Atlanta market (including Comcast and Charter) alongside its existing local carriage on satellite providers DirecTV and Dish Network. Channel 17—which had used the WTBS callsign since 1979—was concurrently relaunched as WPCH and reformatted as a traditional independent station with a separate schedule exclusively catering to the Atlanta market. Although the Atlanta station is no longer carried on American multichannel television providers outside of its home market, WPCH-TV continues to be available as a de facto superstation on most Canadian cable and satellite providers.
History
As WJRJ-TV
On October 20
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