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https://en.wikipedia.org/wiki/Sippenhaft
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Sippenhaft or Sippenhaftung (, kin liability) is a German term for the idea that a family or clan shares the responsibility for a crime or act committed by one of its members, justifying collective punishment. As a legal principle, it was derived from Germanic law in the Middle Ages, usually in the form of fines and compensations. It was adopted by Nazi Germany to justify the punishment of kin (relatives, spouse) for the offence of a family member. Punishment often involved imprisonment and execution, and was applied to relatives of the conspirators of the failed 1944 bomb plot to assassinate Hitler.
Origins
Prior to the adoption of Roman law and Christianity, Sippenhaft was a common legal principle among Germanic peoples, including Anglo-Saxons and Scandinavians. Germanic laws distinguished between two forms of justice for severe crimes such as murder: blood revenge, or extrajudicial killing; and blood money, pecuniary restitution or fines in lieu of revenge, based on the weregild or "man price" determined by the victim's wealth and social status. The principle of Sippenhaft meant that the family or clan of an offender, as well as the offender, could be subject to revenge or could be liable to pay restitution. Similar principles were common to Celts, Teutons, and Slavs.
Nazi Germany
In Nazi Germany, the term was revived to justify the punishment of kin (relatives, spouse) for the offence of a family member. In that form of Sippenhaft, the relatives of persons accused of crimes against the state were held to share the responsibility for those crimes and subject to arrest and sometimes execution.
Examples of Sippenhaft being used as a threat exist within the Wehrmacht from around 1943. Soldiers accused of having "blood impurities" or soldiers conscripted from outside of Germany also began to have their families threatened and punished with Sippenhaft. An example is the case of Panzergrenadier Wenzeslaus Leiss, who was accused of desertion on the Eastern Front in
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https://en.wikipedia.org/wiki/Consensus%20%28computer%20science%29
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A fundamental problem in distributed computing and multi-agent systems is to achieve overall system reliability in the presence of a number of faulty processes. This often requires coordinating processes to reach consensus, or agree on some data value that is needed during computation. Example applications of consensus include agreeing on what transactions to commit to a database in which order, state machine replication, and atomic broadcasts. Real-world applications often requiring consensus include cloud computing, clock synchronization, PageRank, opinion formation, smart power grids, state estimation, control of UAVs (and multiple robots/agents in general), load balancing, blockchain, and others.
Problem description
The consensus problem requires agreement among a number of processes (or agents) for a single data value. Some of the processes (agents) may fail or be unreliable in other ways, so consensus protocols must be fault tolerant or resilient. The processes must somehow put forth their candidate values, communicate with one another, and agree on a single consensus value.
The consensus problem is a fundamental problem in control of multi-agent systems. One approach to generating consensus is for all processes (agents) to agree on a majority value. In this context, a majority requires at least one more than half of available votes (where each process is given a vote). However, one or more faulty processes may skew the resultant outcome such that consensus may not be reached or reached incorrectly.
Protocols that solve consensus problems are designed to deal with limited numbers of faulty processes. These protocols must satisfy a number of requirements to be useful. For instance, a trivial protocol could have all processes output binary value 1. This is not useful and thus the requirement is modified such that the output must somehow depend on the input. That is, the output value of a consensus protocol must be the input value of some process. Another requ
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https://en.wikipedia.org/wiki/Interkinesis
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Interkinesis or interphase II is a period of rest that cells of some species enter during meiosis between meiosis I and meiosis II. No DNA replication occurs during interkinesis; however, replication does occur during the interphase I stage of meiosis (See meiosis I). During interkinesis, the spindles of the first meiotic division disassembles and the microtubules reassemble into two new spindles for the second meiotic division. Interkinesis follows telophase I; however, many plants skip telophase I and interkinesis, going immediately into prophase II. Each chromosome still consists of two chromatids. In this stage other organelle number may also increase.
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https://en.wikipedia.org/wiki/Sum%20of%20angles%20of%20a%20triangle
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In a Euclidean space, the sum of angles of a triangle equals the straight angle (180 degrees, radians, two right angles, or a half-turn).
A triangle has three angles, one at each vertex, bounded by a pair of adjacent sides.
It was unknown for a long time whether other geometries exist, for which this sum is different. The influence of this problem on mathematics was particularly strong during the 19th century. Ultimately, the answer was proven to be positive: in other spaces (geometries) this sum can be greater or lesser, but it then must depend on the triangle. Its difference from 180° is a case of angular defect and serves as an important distinction for geometric systems.
Cases
Euclidean geometry
In Euclidean geometry, the triangle postulate states that the sum of the angles of a triangle is two right angles. This postulate is equivalent to the parallel postulate. In the presence of the other axioms of Euclidean geometry, the following statements are equivalent:
Triangle postulate: The sum of the angles of a triangle is two right angles.
Playfair's axiom: Given a straight line and a point not on the line, exactly one straight line may be drawn through the point parallel to the given line.
Proclus' axiom: If a line intersects one of two parallel lines, it must intersect the other also.
Equidistance postulate: Parallel lines are everywhere equidistant (i.e. the distance from each point on one line to the other line is always the same.)
Triangle area property: The area of a triangle can be as large as we please.
Three points property: Three points either lie on a line or lie on a circle.
Pythagoras' theorem: In a right-angled triangle, the square of the hypotenuse equals the sum of the squares of the other two sides.
Hyperbolic geometry
The sum of the angles of a hyperbolic triangle is less than 180°. The relation between angular defect and the triangle's area was first proven by Johann Heinrich Lambert.
One can easily see how hyperbolic geometry breaks Playf
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https://en.wikipedia.org/wiki/State%20machine%20replication
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In computer science, state machine replication (SMR) or state machine approach is a general method for implementing a fault-tolerant service by replicating servers and coordinating client interactions with server replicas. The approach also provides a framework for understanding and designing replication management protocols.
Problem definition
Distributed service
In terms of clients and services. Each service comprises one or more servers and exports operations that clients invoke by making requests. Although using a single, centralized server is the simplest way to implement a service, the resulting service can only be as fault tolerant as the processor executing that server. If this level of fault tolerance is unacceptable, then multiple servers that fail independently can be used. Usually, replicas of a single server are executed on separate processors of a distributed system, and protocols are used to coordinate client interactions with these replicas.
State machine
For the subsequent discussion a State Machine will be defined as the following tuple of values (See also Mealy machine and Moore Machine):
A set of States
A set of Inputs
A set of Outputs
A transition function (Input × State → State)
An output function (Input × State → Output)
A distinguished State called Start.
A State Machine begins at the State labeled Start. Each Input received is passed through the transition and output function to produce a new State and an Output. The State is held stable until a new Input is received, while the Output is communicated to the appropriate receiver.
This discussion requires a State Machine to be deterministic: multiple copies of the same State Machine begin in the Start state, and receiving the same Inputs in the same order will arrive at the same State having generated the same Outputs.
Typically, systems based on State Machine Replication voluntarily restrict their implementations to use finite-state machines to simplify error recovery.
Fault T
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https://en.wikipedia.org/wiki/Palatopharyngeal%20arch
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The palatopharyngeal arch (pharyngopalatine arch, posterior pillar of fauces) is larger and projects farther toward the middle line than the palatoglossal arch; it runs downward, lateralward, and backward to the side of the pharynx, and is formed by the projection of the palatopharyngeal muscle, covered by mucous membrane.
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https://en.wikipedia.org/wiki/Palatoglossal%20arch
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The palatoglossal arch (glossopalatine arch, anterior pillar of fauces) on either side runs downward, lateral (to the side), and forward to the side of the base of the tongue, and is formed by the projection of the glossopalatine muscle with its covering mucous membrane. It is the anterior border of the isthmus of the fauces and marks the border between the mouth and the palatopharyngeal arch. The latter marks the beginning of the pharynx.
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https://en.wikipedia.org/wiki/Beam%20dump
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A beam dump, also known as a beam block, a beam stop, or a beam trap, is a device designed to absorb the energy of photons or other particles within an energetic beam.
Types of beam dumps
Beam blocks
Beam blocks are simple optical elements that absorb a beam of light using a material with strong absorption and low reflectance. Materials commonly used for beam blocks include certain types of acrylic paint, carbon nanotubes, anodized aluminum, and nickel-phosphate coatings.
Beam traps
Beam traps are used when it is important that there is no reflectance. Beam traps can incorporate materials used for beam blocks in their design to further reduce the possibility of reflectance.
Charged-particle beam dumps
The purpose of a charged-particle beam dump is to safely absorb a beam of charged particles such as electrons, protons, nuclei, or ions. This is necessary when, for example, a circular particle accelerator has to be shut down. Dealing with the heat deposited can be an issue, since the energies of the beams to be absorbed can run into the megajoules.
An example of a charged-particle beam dump is the one used by CERN for the Super Proton Synchrotron. Currently, the SPS uses a beam dump that consists of graphite, molybdenum, and tungsten surrounded by concrete, marble, and cast-iron shielding.
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https://en.wikipedia.org/wiki/C%20date%20and%20time%20functions
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The C date and time functions are a group of functions in the standard library of the C programming language implementing date and time manipulation operations. They provide support for time acquisition, conversion between date formats, and formatted output to strings.
Overview of functions
The C date and time operations are defined in the time.h header file (ctime header in C++).
The and related types were originally proposed by Markus Kuhn to provide a variety of time bases, but only was accepted. The functionalities were, however, added to C++ in 2020 in std::chrono.
Example
The following C source code prints the current time to the standard output stream.
#include <time.h>
#include <stdlib.h>
#include <stdio.h>
int main(void)
{
time_t current_time;
char* c_time_string;
/* Obtain current time. */
current_time = time(NULL);
if (current_time == ((time_t)-1))
{
(void) fprintf(stderr, "Failure to obtain the current time.\n");
exit(EXIT_FAILURE);
}
/* Convert to local time format. */
c_time_string = ctime(¤t_time);
if (c_time_string == NULL)
{
(void) fprintf(stderr, "Failure to convert the current time.\n");
exit(EXIT_FAILURE);
}
/* Print to stdout. ctime() has already added a terminating newline character. */
(void) printf("Current time is %s", c_time_string);
exit(EXIT_SUCCESS);
}
The output is:
Current time is Thu Sep 15 21:18:23 2016
See also
Unix time
Year 2038 problem
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https://en.wikipedia.org/wiki/Rosa%20%C3%97%20damascena
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Rosa × damascena (Latin for damascene rose), more commonly known as the Damask rose, or sometimes as the Iranian Rose, Bulgarian rose, Turkish rose, Taif rose, Arab rose, Ispahan rose and Castile rose, is a rose hybrid, derived from Rosa gallica and Rosa moschata. DNA analysis has shown that a third species, Rosa fedtschenkoana, has made some genetic contributions to the Damask rose.
The flowers are renowned for their fine fragrance, and are commercially harvested for rose oil (either "rose otto" or "rose absolute") used in perfumery and to make rose water and "rose concrete". The flower petals are also edible. They may be used to flavor food, as a garnish, as an herbal tea, and preserved in sugar as gulkand.
It is the national flower of Iran.
Description
The Damask rose is a deciduous shrub growing to tall, the stems densely armed with stout, curved prickles and stiff bristles. The leaves are pinnate, with five (rarely seven) leaflets. The roses are a light to moderate pink to light red. The relatively small flowers grow in groups. The bush has an informal shape. It is considered an important type of Old Rose, and also important for its prominent place in the pedigree of many other types.
Varieties
The hybrid is divided in two varieties:
Summer Damasks (R. × damascena nothovar. damascena) have a short flowering season, only in the summer.
Autumn Damasks (R. × damascena nothovar. semperflorens (Duhamel) Rowley) have a longer flowering season, extending into the autumn; they are otherwise not distinguishable from the summer damasks.
The hybrid Rosa × centifolia is derived in part from Rosa × damascena, as are Bourbon, Portland and hybrid perpetual roses.
The cultivar known as Rosa gallica forma trigintipetala or Rosa damascena 'Trigintipetala' is considered to be a synonym of Rosa × damascena.
'Celsiana' is a flowering semi-double variety.
History
Rosa × damascena is a cultivated flower that is not found growing wild. Recent genetic tests indicate that
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https://en.wikipedia.org/wiki/Cryptographic%20log%20on
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Cryptographic log-on (CLO) is a process that uses Common Access Cards (CAC) and embedded Public Key Infrastructure (PKI) certificates to authenticate a user's identification to a workstation and network. It replaces the username and passwords for identifying and authenticating users. To log-on cryptographically to a CLO-enabled workstation, users simply insert their CAC into their workstation’s CAC reader and provide their Personal Identification Number (PIN).
The Navy/Marine Corps Intranet, among many other secure networks, uses CLO.
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https://en.wikipedia.org/wiki/Mucous%20membrane%20of%20the%20soft%20palate
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The mucous membrane of the soft palate is thin, and covered with stratified squamous epithelium on both surfaces, except near the pharyngeal ostium of the auditory tube, where it is columnar and ciliated.
According to Klein, the mucous membrane on the nasal surface of the soft palate in the fetus is covered throughout by columnar ciliated epithelium, which subsequently becomes squamous; some anatomists state that it is covered with columnar ciliated epithelium, except at its free margin, throughout life.
Beneath the mucous membrane on the oral surface of the soft palate is a considerable amount of adenoid tissue.
The palatine glands form a continuous layer on its posterior surface and around the uvula. They are primarily mucus-secreting glands, as opposed to serous or mixed secreting glands.
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https://en.wikipedia.org/wiki/Palatine%20glands
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The palatine glands form a continuous layer on the posterior surface of the mucous membrane of the soft palate and around the uvula. They are pure mucous glands.
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https://en.wikipedia.org/wiki/Rubroboletus%20satanas
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Rubroboletus satanas, commonly known as Satan's bolete or the Devil's bolete, is a basidiomycete fungus of the bolete family (Boletaceae) and one of its most infamous members. It was known as Boletus satanas before its transfer to the new genus Rubroboletus in 2014, based on molecular phylogenetic data. Found in broad-leaved and mixed woodland in the warmer regions of Europe, it is classified as a poisonous mushroom, known to cause gastrointestinal symptoms of diarrhea and violent vomiting. However, reports of poisoning are rare, due to its striking appearance and at times putrid smell, which discourage casual experimentation.
The squat, brightly coloured fruiting bodies are often massive and imposing, with a pale, dull-coloured velvety cap up to , extraordinarily , very rarely across, yellow to orange-red pores and a bulbous red-patterned stem. The flesh turns blue when cut or bruised, and overripe fruit bodies often emit an unpleasant smell reminiscent of carrion. It is arguably the largest bolete found in Europe.
Taxonomy and phylogeny
Originally known as Boletus satanas, the Satan's bolete was described by German mycologist Harald Othmar Lenz in 1831. Lenz was aware of several reports of adverse reactions from people who had consumed this fungus and apparently felt himself ill from its "emanations" while describing it, hence giving it its sinister epithet. The Greek word (satanas, meaning Satan), is derived from the Hebrew śāṭān (שטן). American mycologist Harry D. Thiers concluded that material from North America matches the species description, however, genetic testing has since confirmed that western North American collections represent Rubroboletus eastwoodiae, a different species.
Genetic analysis published in 2013 revealed that B. satanas and several other red-pored boletes, are part of the "/dupainii" clade (named after B. dupainii), and are distantly nested from the core group of Boletus (including B. edulis and relatives) within the Boletineae. This
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https://en.wikipedia.org/wiki/Quantum%20critical%20point
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A quantum critical point is a point in the phase diagram of a material where a continuous phase transition takes place at absolute zero. A quantum critical point is typically achieved by a continuous suppression of a nonzero temperature phase transition to zero temperature by the application of a pressure, field, or through doping. Conventional phase transitions occur at nonzero temperature when the growth of random thermal fluctuations leads to a change in the physical state of a system. Condensed matter physics research over the past few decades has revealed a new class of phase transitions called quantum phase transitions which take place at absolute zero. In the absence of the thermal fluctuations which trigger conventional phase transitions, quantum phase transitions are driven by the zero point quantum fluctuations associated with Heisenberg's uncertainty principle.
Overview
Within the class of phase transitions, there are two main categories: at a first-order phase transition, the properties shift discontinuously, as in the melting of solid, whereas at a second order phase transition, the state of the system changes in a continuous fashion. Second-order phase transitions are marked by the growth of fluctuations on ever-longer length-scales. These fluctuations are called "critical fluctuations". At the critical point where a second-order transition occurs the critical fluctuations are scale invariant and extend over the entire system. At a nonzero temperature phase transition, the fluctuations that develop at a critical point are governed by classical physics, because the characteristic energy of quantum fluctuations is always smaller than the characteristic Boltzmann thermal energy .
At a quantum critical point, the critical fluctuations are quantum mechanical in nature, exhibiting scale invariance in both space and in time. Unlike classical critical points, where the critical fluctuations are limited to a narrow region around the phase transition, the in
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https://en.wikipedia.org/wiki/Sternocostal%20joints
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The sternocostal joints, also known as sternochondral joints or costosternal articulations, are synovial plane joints of the costal cartilages of the true ribs with the sternum. The only exception is the first rib, which has a synchondrosis joint since the cartilage is directly united with the sternum. The sternocostal joints are important for thoracic wall mobility.
The ligaments connecting them are:
Articular capsules
Interarticular sternocostal ligament
Radiate sternocostal ligaments
Costoxiphoid ligaments
Clinical significance
Ankylosis, joint stiffness caused by ossification, may occur at the sternocostal joints.
See also
Costochondritis
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https://en.wikipedia.org/wiki/Dead-beat%20control
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In discrete-time control theory, the dead-beat control problem consists of finding what input signal must be applied to a system in order to bring the output to the steady state in the smallest number of time steps.
For an Nth-order linear system it can be shown that this minimum number of steps will be at most N (depending on the initial condition), provided that the system is null controllable (that it can be brought to state zero by some input). The solution is to apply feedback such that all poles of the closed-loop transfer function are at the origin of the z-plane. This approach is straightforward for linear systems. However, when it comes to nonlinear systems, dead beat control is an open research problem.
Usage
The sole design parameter in deadbeat control is the sampling period. As the error goes to zero within N sampling periods, the settling time remains within the range of Nh, where h is the sampling parameter.
Also, the magnitude of the control signal increases significantly as the sampling period decreases. Thus, careful selection of the sampling period is crucial when employing this control method.
Finally, since the controller is based upon cancelling plant poles and zeros, these must be known precisely, otherwise the controller will not be deadbeat.
Transfer function of dead-beat controller
Consider that a plant has the transfer function
where
The transfer function of the corresponding dead-beat controller is
where d is the minimum necessary system delay for controller to be realizable. For example, systems with two poles must have at minimum 2 step delay from controller to output, so d = 2.
The closed-loop transfer function is
and has all poles at the origin. In general, a closed loop transfer function which has all of its poles at the origin is called a dead beat transfer function.
Notes
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https://en.wikipedia.org/wiki/Crick%20Lecture
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The Francis Crick Medal and Lecture is a prize lecture of the Royal Society established in 2003 with an endowment from Sydney Brenner, the late Francis Crick's close friend and former colleague. It is delivered annually in biology, particularly the areas which Francis Crick worked (genetics, molecular biology and neurobiology), and also to theoretical work. The medal is also intended for young scientists, i.e. under 40, or at career stage corresponding to being under 40 should their career have been interrupted.
List of lectures
Laureates include:
2022 for making fundamental advances in the molecular, cellular and circuit bases of neuronal computation and for successfully linking these to animal decision behaviour
2021 Serena Nik-Zainal for enormous contributions to understanding the aetiology of cancers by her analyses of mutation signatures in cancer genomes, which is now being applied to cancer therapy
2020 Marta Zlatic for discovering how neural circuits generate behaviour by developing and disseminating definitive techniques, and by discovering fundamental principles governing circuit development and function
2019 Gregory Jefferis for his fundamental discoveries concerning the development and functional logic of sensory information processing
2018 Miratul Muqit in recognition of his research on cell signalling linked to neurodegeneration in Parkinson’s disease
2017 for transforming our understanding of meiotic recombination and of human population history.
2016 Madan Babu Mohan for his major and widespread contributions to computational biology
2015 Rob Klose for his research on how chromatin-based and epigenetic processes contribute to gene regulation
2014 Duncan Odom for his pioneering work in the field of comparative functional genomics
2013 Matthew Hurles on Mutations: great and small
2012 Sarah Teichmann on Finding patterns in genes and proteins: decoding the logic of molecular interactions
2011 Simon Boulton on Repairing the code
2010
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https://en.wikipedia.org/wiki/Linear%20matrix%20inequality
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In convex optimization, a linear matrix inequality (LMI) is an expression of the form
where
is a real vector,
are symmetric matrices ,
is a generalized inequality meaning is a positive semidefinite matrix belonging to the positive semidefinite cone in the subspace of symmetric matrices .
This linear matrix inequality specifies a convex constraint on y.
Applications
There are efficient numerical methods to determine whether an LMI is feasible (e.g., whether there exists a vector y such that LMI(y) ≥ 0), or to solve a convex optimization problem with LMI constraints.
Many optimization problems in control theory, system identification and signal processing can be formulated using LMIs. Also LMIs find application in Polynomial Sum-Of-Squares. The prototypical primal and dual semidefinite program is a minimization of a real linear function respectively subject to the primal and dual convex cones governing this LMI.
Solving LMIs
A major breakthrough in convex optimization was the introduction of interior-point methods. These methods were developed in a series of papers and became of true interest in the context of LMI problems in the work of Yurii Nesterov and Arkadi Nemirovski.
See also
Semidefinite programming
Spectrahedron
Finsler's lemma
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https://en.wikipedia.org/wiki/Ethyl%20pentanoate
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Ethyl pentanoate, also commonly known as ethyl valerate, is an organic compound used in flavors. It is an ester with the molecular formula C7H14O2. This colorless liquid is poorly soluble in water but miscible with organic solvents.
As is the case with most volatile esters, it has a pleasant aroma and taste. It is used as a food additive to impart a fruity flavor, particularly of apple.
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https://en.wikipedia.org/wiki/Butyl%20butyrate
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Butyl butyrate, or butyl butanoate, is an organic compound that is an ester formed by the condensation of butyric acid and n-butanol. It is a clear, colorless liquid that is insoluble in water, but miscible with ethanol and diethyl ether. Its refractive index is 1.406 at 20 °C.
Aroma
Like other volatile esters, butyl butyrate has a pleasant aroma. It is used in the flavor industry to create sweet fruity flavors that are similar to that of pineapple. It occurs naturally in many kinds of fruit including apple, banana, berries, pear, plum, and strawberry.
Safety
It is a marine pollutant. It mildly irritates the eyes and skin.
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https://en.wikipedia.org/wiki/Low-affinity%20nerve%20growth%20factor%20receptor
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The p75 neurotrophin receptor (p75NTR) was first identified in 1973 as the low-affinity nerve growth factor receptor (LNGFR) before discovery that p75NTR bound other neurotrophins equally well as nerve growth factor. p75NTR is a neurotrophic factor receptor. Neurotrophic factor receptors bind Neurotrophins including Nerve growth factor, Neurotrophin-3, Brain-derived neurotrophic factor, and Neurotrophin-4. All neurotrophins bind to p75NTR. This also includes the immature pro-neurotrophin forms. Neurotrophic factor receptors, including p75NTR, are responsible for ensuring a proper density to target ratio of developing neurons, refining broader maps in development into precise connections. p75NTR is involved in pathways that promote neuronal survival and neuronal death.
Receptor family
p75NTR is a member of the tumor necrosis factor receptor superfamily. p75NTR/LNGFR was the first member of this large family of receptors to be characterized, that now contains about 25 receptors, including tumor necrosis factor 1 (TNFR1) and TNFR2, Fas, RANK, and CD40.
All members of the TNFR superfamily contain structurally related cysteine-rich modules in their ECDs. p75NTR is an unusual member of this family due to its propensity to dimerize rather than trimerize, because of its ability to act as a tyrosine kinase co-receptor, and because the neurotrophins are structurally unrelated to the ligands, which typically bind TNFR family members. Indeed, with the exception of p75NTR, essentially all members of the TNFR family preferentially bind structurally related trimeric Type II transmembrane ligands, members of the TNF ligand superfamily.
Structure
p75NTR is a type I transmembrane protein, with a molecular weight of 75 kDa, determined by glycosylation through both N- and O-linkages in the extracellular domain.
It consists of an extracellular domain, a transmembrane domain and an intracellular domain. The extracellular domain consists of a stalk domain connecting the transmembrane
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https://en.wikipedia.org/wiki/Antarafacial%20and%20suprafacial
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Antarafacial (Woodward-Hoffmann symbol a) and suprafacial (s) are two topological concepts in organic chemistry describing the relationship between two simultaneous chemical bond making and/or bond breaking processes in or around a reaction center. The reaction center can be a p- or spn-orbital (Woodward-Hoffmann symbol ω), a conjugated system (π) or even a sigma bond (σ).
The relationship is antarafacial when opposite faces of the π system or isolated orbital are involved in the process (think anti). For a σ bond, it corresponds to involvement of one "interior" lobe and one "exterior" lobe of the bond.
The relationship is suprafacial when the same face of the π system or isolated orbital are involved in the process (think syn). For a σ bond, it corresponds to involvement of two "interior" lobes or two "exterior" lobes of the bond.
The components of all pericyclic reactions, including sigmatropic reactions and cycloadditions, and electrocyclizations, can be classified as either suprafacial or antarafacial, and this determines the stereochemistry. In particular, antarafacial topology corresponds to inversion of configuration for the carbon atom of a [1, n]-sigmatropic rearrangement, and conrotation for electrocyclic ring closure, while suprafacial corresponds to retention and disrotation.
An example is the [1,3]-hydride shift, in which the interacting frontier orbitals are the allyl free radical and the hydrogen 1s orbitals. The suprafacial shift is symmetry-forbidden because orbitals with opposite algebraic signs overlap. The symmetry allowed antarafacial shift would require a strained transition state and is also unlikely. In contrast a symmetry allowed and suprafacial [1,5]-hydride shift is a common event.
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https://en.wikipedia.org/wiki/Social%20organism
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Social organism is a sociological concept, or model, wherein a society or social structure is regarded as a "living organism". The various entities comprising a society, such as law, family, crime, etc., are examined as they interact with other entities of the society to meet its needs. Every entity of a society, or social organism, has a function in helping maintain the organism's stability and cohesiveness.
History
The model, or concept, of society-as-organism is traced by Walter M. Simon from Plato ('the organic theory of society'), and by George R. MacLay from Aristotle (384–322 BCE) through 19th-century and later thinkers, including the French philosopher and founder of sociology, Auguste Comte, the Scottish essayist, historian and philosopher Thomas Carlyle, the English philosopher and polymath Herbert Spencer, and the French sociologist Émile Durkheim.
According to Durkheim, the more specialized the function of an organism or society, the greater its development, and vice versa. The three core activities of a society are culture, politics, and economics. Societal health depends on the harmonious interworking of these three activities.
This concept was further developed beginning in 1904, over the next two decades, by the Austrian philosopher and social reformer Rudolf Steiner in his lectures, essays, and books on the Threefold Social Order. The "health" of a social organism can be thought of as a function of the interaction of culture, politics and rights, and economics, which in theory can be studied, modeled, and analyzed.
During his work on social order, Steiner developed his "Fundamental Social Law" of economic systems: "Most of all,... our times are suffering from the lack of any basic social understanding of how work can be incorporated into the social organism correctly, so that everything we do is truly performed for the sake of our fellow human beings. We can acquire this understanding only by learning to really insert our 'I' into the
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https://en.wikipedia.org/wiki/Calciphylaxis
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Calciphylaxis, also known as calcific uremic arteriolopathy (CUA) or “Grey Scale”, is a rare syndrome characterized by painful skin lesions. The pathogenesis of calciphylaxis is unclear but believed to involve calcification of the small blood vessels located within the fatty tissue and deeper layers of the skin, blood clots, and eventual death of skin cells due to lack of blood flow. It is seen mostly in people with end-stage kidney disease but can occur in the earlier stages of chronic kidney disease and rarely in people with normally functioning kidneys. Calciphylaxis is a rare but serious disease, believed to affect 1-4% of all dialysis patients. It results in chronic non-healing wounds and indicates poor prognosis, with typical life expectancy of less than one year.
Calciphylaxis is one type of extraskeletal calcification. Similar extraskeletal calcifications are observed in some people with high levels of calcium in the blood, including people with milk-alkali syndrome, sarcoidosis, primary hyperparathyroidism, and hypervitaminosis D. In rare cases, certain medications such as warfarin can also result in calciphylaxis.
Signs and symptoms
The first skin changes in calciphylaxis lesions are mottling of the skin and induration in a livedo reticularis pattern. As tissue thrombosis and infarction occurs, a black, leathery eschar in an ulcer with adherent black slough develops. Surrounding the ulcers is usually a plate-like area of indurated skin. These lesions are always extremely painful and most often occur on the lower extremities, abdomen, buttocks, and penis. Lesions are also commonly multiple and bilateral. Because the tissue has infarcted, wound healing seldom occurs, and ulcers are more likely to become secondarily infected. Many cases of calciphylaxis lead to systemic bacterial infection and death.
Calciphylaxis is characterized by the following histologic findings:
systemic medial calcification of the arteries, i.e. calcification of tunica media. Unli
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https://en.wikipedia.org/wiki/Prurigo%20nodularis
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Prurigo nodularis (PN), also known as nodular prurigo, is a skin disease characterised by pruritic (itchy) nodules which usually appear on the arms or legs. Patients often present with multiple excoriated lesions caused by scratching. PN is also known as Hyde prurigo nodularis, Picker's nodules, atypical nodular form of neurodermatitis circumscripta, lichen corneus obtusus.
Lichen simplex chronicus is a distinct clinical entity.
Signs and symptoms
Nodules are discrete, generally symmetric, hyperpigmented or purpuric, and firm. They are greater than 0.5 cm in both width and depth (as opposed to papules which are less than 0.5 cm). They can appear on any part of the body, but generally begin on the arms and legs.
Excoriated lesions are often flat, umbilicated, or have a crusted top.
Nodules may appear to begin in the hair follicles.
Nodule pattern may be follicular.
In true prurigo nodularis, a nodule forms before itching begins. Typically, these nodules are extremely pruritic and are alleviated only by steroids.
Causes
The cause of prurigo nodularis is unknown, although other conditions may induce PN. PN has been linked to Becker's nevus, linear IgA disease, an autoimmune condition, liver disease and T cells. Systemic pruritus has been linked to cholestasis, thyroid disease, polycythaemia rubra vera, uraemia, Hodgkins disease, HIV and other immunodeficiency diseases. Internal malignancies, liver failure, kidney failure, and psychiatric illnesses have been considered to induce PN, although more recent research has refuted a psychiatric cause for PN. Patients report an ongoing battle to distinguish themselves from those with psychiatric disorders, such as delusions of parasitosis and other psychiatric conditions.
Pathophysiology
Chronic and repetitive scratching, picking, or rubbing of the nodules may result in permanent changes to the skin, including nodular lichenification, hyperkeratosis, hyperpigmentation, and skin thickening. Unhealed, excoriated lesion
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https://en.wikipedia.org/wiki/Marine%20ecosystem
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Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, seagrass meadows, mangroves, rocky intertidal systems, salt marshes, coral reefs, lagoons. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web. Marine ecosystems are characterized by the biological community of organisms that they are associated with and their physical environment. Classes of organisms found in marine ecosystems include brown algae, dinoflagellates, corals, cephalopods, echinoderms, and sharks.
Marine ecosystems are important sources of ecosystem services and food and jobs for significant portions of the global population. Human uses of marine ecosystems and pollution in marine ecosystems are significantly threats to the stability of these ecosystems. Environmental problems concerning marine ecosystems include unsustainable exploitation of marine resources (for example overfishing of certain species), marine pollution, climate change, and building on coastal areas. Moreover, much of the carbon dioxide causing global warming and heat captured by global warming are absorbed by the ocean, ocean chemistry is changing through
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https://en.wikipedia.org/wiki/Multiple%20description%20coding
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Multiple description coding (MDC) in computing is a coding technique that fragments a single media stream into n substreams (n ≥ 2) referred to as descriptions. The packets of each description are routed over multiple, (partially) disjoint paths. In order to decode the media stream, any description can be used, however, the quality improves with the number of descriptions received in parallel. The idea of MDC is to provide error resilience to media streams. Since an arbitrary subset of descriptions can be used to decode the original stream, network congestion or packet loss — which are common in best-effort networks such as the Internet — will not interrupt the stream but only cause a (temporary) loss of quality. The quality of a stream can be expected to be roughly proportional to data rate sustained by the receiver.
MDC is a form of data partitioning, thus comparable to layered coding as it is used in MPEG-2 and MPEG-4. Yet, in contrast to MDC, layered coding mechanisms generate a base layer and n enhancement layers. The base layer is necessary for the media stream to be decoded, enhancement layers are applied to improve stream quality. However, the first enhancement layer depends on the base layer and each enhancement layer n + 1 depends on its subordinate layer n, thus can only be applied if n was already applied. Hence, media streams using the layered approach are interrupted whenever the base layer is missing and, as a consequence, the data of the respective enhancement layers is rendered useless. The same applies for missing enhancement layers. In general, this implies that in lossy networks the quality of a media stream is not proportional to the amount of correctly received data.
Besides increased fault tolerance, MDC allows for rate-adaptive streaming: Content providers send all descriptions of a stream without paying attention to the download limitations of clients. Receivers that cannot sustain the data rate only subscribe to a subset of these streams,
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https://en.wikipedia.org/wiki/Subaudible%20tone
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A subaudible tone is a tone that is used to trigger an automated event at a radio station. A subaudible tone is audible; however, it is usually at a low level that is not noticeable to the average listener at normal volumes. It is a form of in-band signaling.
Overview
These tones are included in the audible main portion of audio in the case of satellite; on tape, these often are filtered. Normally, subaudible tones are at one of the following frequencies: 25, 35, 50, 75 hertz (Hz), or combinations of those frequencies. Until computerized radio automation became inexpensive and common, 25 and 35 Hz were used either in the audio stream or, in the case of tape cartridges used in radio broadcasting (better known as "carts"), on a special track on the tape to indicate to a radio station's automation system that it was time to trigger another event.
With the advent of computers and digital satellite, these tones are relegated to triggering commercial announcements and legal IDs on a dwindling number of radio networks, as tones in the audio have been supplanted by external data channels sent independent of audio on digital satellite feeds for radio. These trigger relay closure terminals on the satellite receiver itself (Starguide being a prominent system).
Use for filmstrips
Subaudible tones have also been used by later filmstrip projectors to advance to the next frame in a filmstrip presentation. Previously, the phonographic record or audio cassette accompanying a filmstrip to provide its soundtrack would have an audible tone to signal the person operating the projector to advance the film to the next frame. But automatic filmstrip projectors were introduced in the 1970s (that had an integrated phonograph or cassette player) that would read a subaudible tone of 50 Hz recorded on the soundtrack to automatically trigger the projector to advance to the next frame.
Most of the cassettes accompanying filmstrips from the 1970s and 80s would have one side of the med
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https://en.wikipedia.org/wiki/Tetramethylenedisulfotetramine
|
Tetramethylenedisulfotetramine (TETS) is an organic compound used as a rodenticide (rat poison). It is an odorless, tasteless white powder that is slightly soluble in water, DMSO and acetone, and insoluble in methanol and ethanol. It is a sulfamide derivative. It can be synthesized by reacting sulfamide with formaldehyde solution in acidified water. When crystallized from acetone, it forms cubic crystals with a melting point of 255–260 °C.
Toxicity and mechanism
TETS is a neurotoxin and convulsant, causing lethal convulsions. Its effect is similar to but stronger than picrotoxin, a GABA-A receptor antagonist widely used in research. As one of the most hazardous pesticides, it is 100 times more toxic than potassium cyanide. TETS binds to neuronal GABA gated chloride channels, often causing status epilepticus. No antidote is known. The lethal dose for humans is 7–10 mg. Poisoning is diagnosed by GC-MS and the treatment is mainly supportive, with large IV doses of a benzodiazepine (e.g clonazepam) and pyridoxine to control symptoms. TETS is sequestered in tissues of poisoned birds and can thus pose severe risk of secondary poisoning.
History
Previous research has documented the effectiveness of Tetramethylenedisulfotetramine against mice. The dangers of this chemical were first suspected in 1949. The U.S. Forest Service, looking to protect tree seeds for reforestation, noted its lethal effect against the rodent populations. Rather than repel wandering scavengers, the chemical was proved to be toxic to the local rodent population for up to 4 years. Continued experiments conducted by the U.S. Forest Service found no direct effect between TETS and the gastro-intestinal or renal systems of spinal dogs. In this same study, no effects were seen within the peripheral or skeletal nerve system, limiting symptoms of toxicity to the brain stem. Curtis and Johnson were the first to hypothesize TETS antagonistic behavior on GABA. An in-vitro study using superior cervical gangli
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https://en.wikipedia.org/wiki/Swedish%20Food%20Workers%27%20Union
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The Swedish Food Workers' Union (, Livs) is a trade union representing workers in the food and drink industries in Sweden.
The union was founded on 1 January 1922, when the Swedish Bakery and Confectionery Workers' Union merged with the Swedish Butchers' Union. Like both its predecessors, it affiliated to the Swedish Trade Union Confederation. On foundation, it had 9,372 members and by 1959 had grown to 38,053. The Swedish Tobacco Industry Workers' Union joined in 1964, followed by the Swedish Brewery Industry Workers' Union in 1965, and the dairy workers' section of the Swedish Commercial Employees' Union in 1968. Its all-time peak membership was 53,131 in 1985, but this dropped to 22,877 by 2019.
The Union launched a campaign called "Scandal" in December 2013 to highlight working conditions at Scan, Sweden's largest meat company. The campaign was successful and the Union signed an agreement with Scan.
Presidents
1922: J. O. Ödlund
1923: John Rosenberg
1927: Hilding Molander
1948: Oscar Persson
1956: Anton Johansson
1966: Stig Ögersten
1969: Åke Berggren
1979: Lage Andréasson
1991: Kjell Varenblad
1996: Åke Södergren
2005: Hans-Olof Nilsson
2017: Eva Guovelin
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https://en.wikipedia.org/wiki/GRANK
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GRANK, or Global Rank is a ranking of the rarity of a species, and is a useful tool in determining conservation needs.
Global Ranks are derived from a consensus of various conservation data centres, natural heritage programmes, scientific experts and NatureServe.
They are based on the total number of known, extant populations worldwide, and to what degree they are threatened by destruction. Criteria also include securely protected populations, size of populations, and the ability of the species to persist.
G1 — Critically Imperiled At very high risk of extinction or collapse due to very restricted range, very few populations or occurrences, very steep declines, very severe threats, or other factors.
G2 — Imperiled At high risk of extinction or collapse due to restricted range, few populations or occurrences, steep declines, severe threats, or other factors.
G3 — Vulnerable At moderate risk of extinction or collapse due to a fairly restricted range, relatively few populations or occurrences, recent and widespread declines, threats, or other factors.
G4 — Apparently Secure At fairly low risk of extinction or collapse due to an extensive range and/or many populations or occurrences, but with possible cause for some concern as a result of local recent declines, threats, or other factors.
G5 — Secure At very low risk or extinction or collapse due to a very extensive range, abundant populations or occurrences, and little to no concern from declines or threats.
GH — Possibly Extinct (species) or Possibly Collapsed (ecosystems/communities) Known from only historical occurrences but still some hope of rediscovery. Examples of evidence include (1) that a species has not been documented in approximately 20-40 years despite some searching and/or some evidence of significant habitat loss or degradation; (2) that a species or ecosystem has been searched for unsuccessfully, but not thoroughly enough to presume that it is extinct or collapsed throughout its range.
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https://en.wikipedia.org/wiki/NRANK
|
NRANK, or National Rank, is a ranking of the rarity of a species within a nation. Each nation can assign their own NRANK based on information from conservation data centres, natural heritage programmes, and expert scientists.
Taxonomy (biology)
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https://en.wikipedia.org/wiki/Active%20object
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The active object design pattern decouples method execution from method invocation for objects that each reside in their own thread of control. The goal is to introduce concurrency, by using asynchronous method invocation and a scheduler for handling requests.
The pattern consists of six elements:
A proxy, which provides an interface towards clients with publicly accessible methods.
An interface which defines the method request on an active object.
A list of pending requests from clients.
A scheduler, which decides which request to execute next.
The implementation of the active object method.
A callback or variable for the client to receive the result.
Example
Java
An example of active object pattern in Java.
Firstly we can see a standard class that provides two methods that set a double to be a certain value. This class does NOT conform to the active object pattern.
class MyClass {
private double val = 0.0;
void doSomething() {
val = 1.0;
}
void doSomethingElse() {
val = 2.0;
}
}
The class is dangerous in a multithreading scenario because both methods can be called simultaneously, so the value of val (which is not atomic—it's updated in multiple steps) could be undefined—a classic race condition. You can, of course, use synchronization to solve this problem, which in this trivial case is easy. But once the class becomes realistically complex, synchronization can become very difficult.
To rewrite this class as an active object, you could do the following:
class MyActiveObject {
private double val = 0.0;
private BlockingQueue<Runnable> dispatchQueue = new LinkedBlockingQueue<Runnable>();
public MyActiveObject() {
new Thread (new Runnable() {
@Override
public void run() {
try {
while (true) {
dispatchQueue.take().run();
}
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https://en.wikipedia.org/wiki/Lipid%20signaling
|
Lipid signaling, broadly defined, refers to any biological cell signaling event involving a lipid messenger that binds a protein target, such as a receptor, kinase or phosphatase, which in turn mediate the effects of these lipids on specific cellular responses. Lipid signaling is thought to be qualitatively different from other classical signaling paradigms (such as monoamine neurotransmission) because lipids can freely diffuse through membranes (see osmosis). One consequence of this is that lipid messengers cannot be stored in vesicles prior to release and so are often biosynthesized "on demand" at their intended site of action. As such, many lipid signaling molecules cannot circulate freely in solution but, rather, exist bound to special carrier proteins in serum.
Sphingolipid second messengers
Ceramide
Ceramide (Cer) can be generated by the breakdown of sphingomyelin (SM) by sphingomyelinases (SMases), which are enzymes that hydrolyze the phosphocholine group from the sphingosine backbone. Alternatively, this sphingosine-derived lipid (sphingolipid) can be synthesized from scratch (de novo) by the enzymes serine palmitoyl transferase (SPT) and ceramide synthase in organelles such as the endoplasmic reticulum (ER) and possibly, in the mitochondria-associated membranes (MAMs) and the perinuclear membranes. Being located in the metabolic hub, ceramide leads to the formation of other sphingolipids, with the C1 hydroxyl (-OH) group as the major site of modification. A sugar can be attached to ceramide (glycosylation) through the action of the enzymes, glucosyl or galactosyl ceramide synthases. Ceramide can also be broken down by enzymes called ceramidases, leading to the formation of sphingosine, Moreover, a phosphate group can be attached to ceramide (phosphorylation) by the enzyme, ceramide kinase. It is also possible to regenerate sphingomyelin from ceramide by accepting a phosphocholine headgroup from phosphatidylcholine (PC) by the action of an enzyme called
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https://en.wikipedia.org/wiki/Gottfrid%20Svartholm
|
Per Gottfrid Svartholm Warg (born 17 October 1984), alias anakata, is a Swedish computer specialist, known as the former co-owner of the web hosting company PRQ and co-founder of the BitTorrent site The Pirate Bay together with Fredrik Neij and Peter Sunde.
Parts of an interview with Svartholm commenting on the May 2006 police raid of The Pirate Bay are featured in Good Copy Bad Copy and Steal This Film. He is a main focus of the documentary TPB AFK.
In May 2013, WikiLeaks said Svartholm Warg had worked with the organization for the 2010 release of Collateral Murder, the helicopter cockpit gunsight video of a July 2007 airstrike by U.S. forces in Baghdad. According to WikiLeaks, Svartholm served as technical consultant and managed infrastructure critical to the organization. He was also listed as part of the “decryption and transmission team” and credited for “networking.” Svartholm was one of several Pirate Bay associates who did work for other Wikileaks endeavors. One of Svartholm's companies had previously hosted WikiLeaks' computers.
On 27 November 2013, he was extradited to Denmark, where he was charged with infiltrating the Danish social security database, driver's licence database, and the shared IT system used in the Schengen zone. Awaiting his court trial, he was being held in solitary confinement. A court trial ended on 31 October 2014, and he was found guilty by the jury and sentenced to three and a half years in prison. The sentence was appealed immediately, but the judges, fearing that he might try to evade his sentence, ordered that he be held in confinement until the appeal court trial date.
After spending three years in different prisons in both Sweden and Denmark, he was eventually released on 29 September 2015. According to his mother, he expressed a desire ‘to get back to his developmental work within IT’ upon his release.
Americas Dumbest Soldiers and meeting Fredrik Neij
Svartholm Warg started the website Americas Dumbest Soldiers which li
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https://en.wikipedia.org/wiki/PRQ
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PRQ is a Swedish Internet service provider and web hosting company created in 2004.
Ownership
Based in Stockholm, PRQ was created by Gottfrid Svartholm and Fredrik Neij, two founders of The Pirate Bay.
Business model
Part of PRQ's business model is to host any customers, regardless of how odd or controversial they may be. The New York Times wrote in 2008 that "The Pirate Bay guys have made a sport out of taunting all forms of authority, including the Swedish police, and PRQ has gone out of its way to be a host to sites that other companies would not touch." The PRQ service has been described as "highly secure, no-questions-asked hosting services". The company holds almost no information about its clientele and is maintaining few if any of its own logs, according to a 2008 news report. Fredrik Neij and Gottfrid Svartholm are said to have amassed "considerable expertise in withstanding legal attacks". Svartholm is quoted to have said, "We do employ our own legal staff. We are used to this sort of situation" in a telephone interview. Due to hosting The Pirate Bay, PRQ was the target of a police raid.
Criticism
The co-founders have been criticized for hosting controversial websites, including web pages that promote paedophilia, such as the North American Man/Boy Love Association (NAMBLA), a paedophile and pederasty advocacy organization. Local authorities and anti-paedophilia activists in Sweden have failed to persuade PRQ to close the sites. The pair defended their decision, citing freedom of speech.
The co-owners were also criticized for creating and hosting AMERICASDUMBESTSOLDIERS.COM, a website identifying deceased military personnel that invited visitors to rank how "dumb" the soldiers were based on the manner in which they died.
Other criticism originates from the hosting of BitTorrent website The Pirate Bay, WikiLeaks, and the French far-right blog Fdesouche.
Legal issues
On 1 October 2012, PRQ was raided and a number of sites which they provided hosting
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https://en.wikipedia.org/wiki/ArchNet
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Archnet is a collaborative digital humanities project focused on Islamic architecture and the built environment of Muslim societies. Conceptualized in 1998 and originally developed at the MIT School of Architecture and Planning in co-operation with the Aga Khan Trust for Culture. It has been maintained by the Aga Khan Documentation Center at MIT and the Aga Khan Trust for Culture since 2011.
Archnet is an open access resource providing all users with resources on architecture, urban design and development in the Muslim world.
History and Conceptualization
The Aga Khan Trust for Culture (AKTC) is an agency of the Aga Khan Development Network (AKDN). Through various programmes, partnerships, and initiatives, the AKTC seeks to improve the built environment in Asia and Africa where there is a significant Muslim presence. Archnet complements the work of the Trust by making its resources digitally accessible to individuals worldwide.
Archnet was conceptualized in 1998 during a series of discussions between Aga Khan IV; the President of the Massachusetts Institute of Technology (MIT) Charles Vest; and the Dean of MIT’s School of Architecture and Planning, William J. Mitchell. The foundations of Archnet were predicated on remarks made by Aga Khan in Istanbul in 1983, about his desire to make available the extensive dossiers resulting from the nominations for the Aga Khan Award for Architecture (AKAA) for the purpose of “[assisting] those institutions where the professionals of the future are trained.”
The purpose of the website is to create a viable platform upon which knowledge pertaining to the field of architecture can be shared. Archnet aims to expand the general intellectual frame of reference to transcend the barriers of geography, socio-economic status and religion, and to foster a spirit of collaboration and open dialogue. Archnet therefore manifests many of the Aga Khan’s values and principles regarding not only rural and urban development but also pluralism a
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https://en.wikipedia.org/wiki/Artin%20billiard
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In mathematics and physics, the Artin billiard is a type of a dynamical billiard first studied by Emil Artin in 1924. It describes the geodesic motion of a free particle on the non-compact Riemann surface where is the upper half-plane endowed with the Poincaré metric and is the modular group. It can be viewed as the motion on the fundamental domain of the modular group with the sides identified.
The system is notable in that it is an exactly solvable system that is strongly chaotic: it is not only ergodic, but is also strong mixing. As such, it is an example of an Anosov flow. Artin's paper used symbolic dynamics for analysis of the system.
The quantum mechanical version of Artin's billiard is also exactly solvable. The eigenvalue spectrum consists of a bound state and a continuous spectrum above the energy . The wave functions are given by Bessel functions.
Exposition
The motion studied is that of a free particle sliding frictionlessly, namely, one having the Hamiltonian
where m is the mass of the particle, are the coordinates on the manifold, are the conjugate momenta:
and
is the metric tensor on the manifold. Because this is the free-particle Hamiltonian, the solution to the Hamilton-Jacobi equations of motion are simply given by the geodesics on the manifold.
In the case of the Artin billiards, the metric is given by the canonical Poincaré metric
on the upper half-plane. The non-compact Riemann surface is a symmetric space, and is defined as the quotient of the upper half-plane modulo the action of the elements of acting as Möbius transformations. The set
is a fundamental domain for this action.
The manifold has, of course, one cusp. This is the same manifold, when taken as the complex manifold, that is the space on which elliptic curves and modular functions are studied.
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https://en.wikipedia.org/wiki/ICMP%20tunnel
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An ICMP tunnel establishes a covert connection between two remote computers (a client and proxy), using ICMP echo requests and reply packets. An example of this technique is tunneling complete TCP traffic over ping requests and replies.
Technical details
ICMP tunneling works by injecting arbitrary data into an echo packet sent to a remote computer. The remote computer replies in the same manner, injecting an answer into another ICMP packet and sending it back. The client performs all communication using ICMP echo request packets, while the proxy uses echo reply packets.
In theory, it is possible to have the proxy use echo request packets (which makes implementation much easier), but these packets are not necessarily forwarded to the client, as the client could be behind a translated address (NAT). This bidirectional data flow can be abstracted with an ordinary serial line.
ICMP tunneling is possible because RFC 792, which defines the structure of ICMP packets, allows for an arbitrary data length for any type 0 (echo reply) or 8 (echo message) ICMP packets.
Uses
ICMP tunneling can be used to bypass firewalls rules through obfuscation of the actual traffic. Depending on the implementation of the ICMP tunneling software, this type of connection can also be categorized as an encrypted communication channel between two computers. Without proper deep packet inspection or log review, network administrators will not be able to detect this type of traffic through their network.
Mitigation
One way to prevent this type of tunneling is to block ICMP traffic, at the cost of losing some network functionality that people usually take for granted (e.g. it might take tens of seconds to determine that a peer is offline, rather than almost instantaneously). Another method for mitigating this type of attack is to only allow fixed sized ICMP packets through firewalls, which can impede or eliminate this type of behavior.
ICMP-tunnels are sometimes used to circumvent firewalls th
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https://en.wikipedia.org/wiki/Pesticides%20Safety%20Directorate
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The Pesticides Safety Directorate was an agency of the Department for Environment, Food and Rural Affairs (Defra). It was based in York, England, with about 200 scientific, policy and support staff and was responsible for the authorisation of plant protection products and, from 2005, detergents, in the United Kingdom.
In April 2008, it joined the Health and Safety Executive (HSE), and in April 2009, became part of a newly formed Chemicals Regulation Directorate (CRD) at the HSE.
Aims of the Pesticides Safety Directorate
To ensure the safe use of pesticides and detergents for people and the environment.
To harmonise pesticide regulation within the European Community and provide a level playing field for crop protection.
As part of the strategy for sustainable food and farming, to reduce negative impacts of pesticides on the environment.
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https://en.wikipedia.org/wiki/Monogamy%20in%20animals
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Monogamous pairing in animals refers to the natural history of mating systems in which species pair bond to raise offspring. This is associated, usually implicitly, with sexual monogamy.
Monogamous mating
Monogamy is defined as a pair bond between two adult animals of the same species. This pair may cohabitate in an area or territory for some duration of time, and in some cases may copulate and reproduce with only each other. Monogamy may either be short-term, lasting one to a few seasons or long-term, lasting many seasons and in extreme cases, life-long. Monogamy can be partitioned into two categories, social monogamy and genetic monogamy which may occur together in some combination, or completely independently of one another. As an example, in the cichlid species Variabilichromis moorii, a monogamous pair will care for eggs and young together, but the eggs may not all be fertilized by the male giving the care. Monogamy in mammals is rather rare, only occurring in 3–9% of these species. A larger percentage of avian species are known to have monogamous relationships (about 90%), but most avian species practice social but not genetic monogamy in contrast to what was previously assumed by researchers. Monogamy is quite rare in fish and amphibians, but not unheard of, appearing in a select few species.
Social monogamy
Social monogamy refers to the cohabitation of one male and one female. The two individuals may cooperate in search of resources such as food and shelter and/or in caring for young. Paternal care in monogamous species is commonly displayed through carrying, feeding, defending, and socializing offspring. With social monogamy there may not be an expected sexual fidelity between the males and the females. The existence of purely social monogamy is a polygamous or polyandrous social pair with extra pair coupling. Social monogamy has been shown to increase fitness in prairie voles. It has been shown that female prairie voles live longer when paired with males
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https://en.wikipedia.org/wiki/Voigt%20effect
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The Voigt effect is a magneto-optical phenomenon which rotates and elliptizes linearly polarised light sent into an optically active medium. Unlike many other magneto-optical effects such as the Kerr or Faraday effect which are linearly proportional to the magnetization (or to the applied magnetic field for a non magnetized material), the Voigt effect is proportional to the square of the magnetization (or square of the magnetic field) and can be seen experimentally at normal incidence. There are several denominations for this effect in the literature: the Cotton–Mouton effect (in reference to French scientists Aimé Cotton and Henri Mouton), the Voigt effect (in reference to the German scientist Woldemar Voigt), and magnetic-linear birefringence. This last denomination is closer in the physical sense, where the Voigt effect is a magnetic birefringence of the material with an index of refraction parallel () and perpendicular ) to the magnetization vector or to the applied magnetic field.
For an electromagnetic incident wave linearly polarized and an in-plane polarized sample , the expression of the rotation in reflection geometry is is:
and in the transmission geometry:
where is the difference of refraction indices depending on the Voigt parameter (same as for the Kerr effect), the material refraction indices and the parameter responsible of the Voigt effect and so proportional to the or in the case of a paramagnetic material.
Detailed calculation and an illustration are given in sections below.
Theory
As with the other magneto-optical effects, the theory is developed in a standard way with the use of an effective dielectric tensor from which one calculates systems eigenvalues and eigenvectors. As usual, from this tensor, magneto-optical phenomena are described mainly by the off-diagonal elements.
Here, one considers an incident polarisation propagating in the z direction: the electric field and a homogenously in-plane magnetized sample where is cou
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https://en.wikipedia.org/wiki/Hadamard%27s%20dynamical%20system
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In physics and mathematics, the Hadamard dynamical system (also called Hadamard's billiard or the Hadamard–Gutzwiller model) is a chaotic dynamical system, a type of dynamical billiards. Introduced by Jacques Hadamard in 1898, and studied by Martin Gutzwiller in the 1980s, it is the first dynamical system to be proven chaotic.
The system considers the motion of a free (frictionless) particle on the Bolza surface, i.e, a two-dimensional surface of genus two (a donut with two holes) and constant negative curvature; this is a compact Riemann surface. Hadamard was able to show that every particle trajectory moves away from every other: that all trajectories have a positive Lyapunov exponent.
Frank Steiner argues that Hadamard's study should be considered to be the first-ever examination of a chaotic dynamical system, and that Hadamard should be considered the first discoverer of chaos. He points out that the study was widely disseminated, and considers the impact of the ideas on the thinking of Albert Einstein and Ernst Mach.
The system is particularly important in that in 1963, Yakov Sinai, in studying Sinai's billiards as a model of the classical ensemble of a Boltzmann–Gibbs gas, was able to show that the motion of the atoms in the gas follow the trajectories in the Hadamard dynamical system.
Exposition
The motion studied is that of a free particle sliding frictionlessly on the surface, namely, one having the Hamiltonian
where m is the mass of the particle, , are the coordinates on the manifold, are the conjugate momenta:
and
is the metric tensor on the manifold. Because this is the free-particle Hamiltonian, the solution to the Hamilton–Jacobi equations of motion are simply given by the geodesics on the manifold.
Hadamard was able to show that all geodesics are unstable, in that they all diverge exponentially from one another, as with positive Lyapunov exponent
with E the energy of a trajectory, and being the constant negative curvature of the surface.
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https://en.wikipedia.org/wiki/Abruzzo%E2%80%93Erickson%20syndrome
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Abruzzo–Erickson syndrome is an extremely rare disorder characterized by deafness, protruding ears, coloboma, a cleft palate or palatal rugosity, radial synostosis, and short stature. It was first characterized by Abruzzo and Erickson in 1977 as a CHARGE like syndrome as variably expressed among a family of two brothers, their mother, and their maternal uncle. Members of this family exhibited many of the CHARGE symptoms, but notably did not have choanal atresia and the brothers experienced typical genital development. Due to the recent discovery of this disorder, its etiology is not fully known but it is understood that it arises from mutations on the TBX22 gene on the X-chromosome. The disorder is inherited in an X-linked recessive manner. There is currently no known cure but its symptoms can be treated.
Signs and Symptoms
Abruzzo-Erikson syndrome is characterized by cleft palate, coloboma, hypospadias, deafness, short stature, and radial synostosis. There are also additional symptoms that are very similar to CHARGE syndrome such as large and protruding ears, wide spacing between the second and third fingers, ulnar deviation, facial asymmetry, dental abnormalities, and congenital heart malformation. However, in contrast to CHARGE syndrome, patients with Abruzzo-Erikson syndrome do not display intellectual disability, choanal atresia, or genital hypoplasia. As with most diseases, the symptoms will vary from person to person.
Genetics
While the complete etiology is not fully known, Abruzzo-Erickson Syndrome arises in part due to mutations on the TBX22 gene, a gene that is located on the X-chromosome (around 80,014,753 to 80,031,774 bp), and is inherited in an X-linked recessive manner. The T-box transcription factor TBX22 plays an essential role in normal craniofacial development. Nonsense, frameshift, splice-site and missense mutations in this region can result in patients with X-linked cleft palate (CPX) and ankyloglossia phenotypes. The CPX phenotype observed
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https://en.wikipedia.org/wiki/Full%20state%20feedback
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Full state feedback (FSF), or pole placement, is a method employed in feedback control system theory to place the closed-loop poles of a plant in pre-determined locations in the s-plane. Placing poles is desirable because the location of the poles corresponds directly to the eigenvalues of the system, which control the characteristics of the response of the system. The system must be considered controllable in order to implement this method.
Principle
If the closed-loop dynamics can be represented by the state space equation (see State space (controls))
with output equation
then the poles of the system transfer function are the roots of the characteristic equation given by
Full state feedback is utilized by commanding the input vector . Consider an input proportional (in the matrix sense) to the state vector,
.
Substituting into the state space equations above, we have
The poles of the FSF system are given by the characteristic equation of the matrix , . Comparing the terms of this equation with those of the desired characteristic equation yields the values of the feedback matrix which force the closed-loop eigenvalues to the pole locations specified by the desired characteristic equation.
Example of FSF
Consider a system given by the following state space equations:
The uncontrolled system has open-loop poles at and . These poles are the eigenvalues of the matrix and they are the roots of . Suppose, for considerations of the response, we wish the controlled system eigenvalues to be located at and , which are not the poles we currently have. The desired characteristic equation is then , from .
Following the procedure given above, the FSF controlled system characteristic equation is
where
Upon setting this characteristic equation equal to the desired characteristic equation, we find
.
Therefore, setting forces the closed-loop poles to the desired locations, affecting the response as desired.
This only works for Single-Input systems. Mult
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https://en.wikipedia.org/wiki/Advection%20upstream%20splitting%20method
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The Advection Upstream Splitting Method (AUSM) is a numerical method used to solve the advection equation in computational fluid dynamics. It is particularly useful for simulating compressible flows with shocks and discontinuities.
The AUSM is developed as a numerical inviscid flux function for solving a general system of conservation equations. It is based on the upwind concept and was motivated to provide an alternative approach to other upwind methods, such as the Godunov method, flux difference splitting methods by Roe, and Solomon and Osher, flux vector splitting methods by Van Leer, and Steger and Warming.
The AUSM first recognizes that the inviscid flux consist of two physically distinct parts, i.e., convective and pressure fluxes. The former is associated with the flow (advection) speed, while the latter with the acoustic speed; or respectively classified as the linear and nonlinear fields. Currently, the convective and pressure fluxes are formulated using the eigenvalues of the flux Jacobian matrices. The method was originally proposed by Liou and Steffen for the typical compressible aerodynamic flows, and later substantially improved in to yield a more accurate and robust version. To extend its capabilities, it has been further developed in for all speed-regimes and multiphase flow. Its variants have also been proposed.
Features
The Advection Upstream Splitting Method has many features. The main features are:
accurate capturing of shock and contact discontinuities
entropy-satisfying solution
positivity-preserving solution
algorithmic simplicity (not requiring explicit eigen-structure of the flux Jacobian matrices) and straightforward extension to additional conservation laws
free of “carbuncle” phenomena
uniform accuracy and convergence rate for all Mach numbers.
Since the method does not specifically require eigenvectors, it is especially attractive for the system whose eigen-structure is not known explicitly, as the case of two-fluid equations for
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https://en.wikipedia.org/wiki/Drive%20mapping
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Drive mapping is how MS-DOS and Microsoft Windows associate a local drive letter (A through Z) with a shared storage area to another computer (often referred as a File Server) over a network. After a drive has been mapped, a software application on a client's computer can read and write files from the shared storage area by accessing that drive, just as if that drive represented a local physical hard disk drive.
Drive mapping
Mapped drives are hard drives (even if located on a virtual or cloud computing system, or network drives) which are always represented by names, letter(s), or number(s) and they are often followed by additional strings of data, directory tree branches, or alternate level(s) separated by a "\" symbol. Drive mapping is used to locate directories, files or objects, and programs or apps, and is needed by end users, administrators, and various other operators or groups.
Mapped drives are usually assigned a letter of the alphabet after the first few taken, such as A:\, B:\ (both of which were historically removable flexible magnetic media drives), C:\ (usually the first or only installed hard disk), and D:\ (which was often an optical drive unit). Then, with the drive and/or directory (letters, symbols, numbers, names) mapped, they can be entered into the necessary address bar/location(s) and displayed as in the following:
Example 1:
C:\level\next level\following level
or
C:\BOI60471CL\Shared Documents\Multi-Media Dept
The preceding location may reach something like a company's multi-media department's database, which logically is represented with the entire string "C:\BDB60471CL\Shared Documents\Multi-Media Dept".
Mapping a drive can be complicated for a complex system. Network mapped drives (on LANs or WANs) are available only when the host computer (File Server) is also available (i.e. online): it is a requirement for use of drives on a host. All data on various mapped drives will have certain permissions set (most newer systems) and the
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https://en.wikipedia.org/wiki/Do%21%20Run%20Run
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Do! Run Run, also known as Super Pierrot (スーパーピエロ Sūpā Piero), is the fourth and final incarnation of Mr. Do!, the Universal video game mascot. Returning to his Mr. Do! roots, the clown has a bouncing powerball with which to hurl at monsters. Mr. Do runs along the playfield picking up dots and leaving a line behind him, which the player is encouraged to create closed off sections with. Precariously balanced log traps can be rolled downslope, crushing enemies. The resulting game is something of a cross between Mr. Do!, Congo Bongo, Pac-Man, and Qix.
Gameplay
The goal of Do! Run Run is to rack up points while completing screens. A screen is completed whenever all the fruits/dots are eaten, or when all of the regular monsters (not Alpha-monsters or their sidekicks) are defeated. Using the rope that follows Mr. Do to inscribe dots will convert them into cherries, a familiar fruit for Mr. Do to collect. Cherries are worth more points than dots, and eating them restores the powerball more quickly than eating dots would. Each time Mr. Do inscribes fruit, they progress to a higher tier, dots become cherries, cherries become apples, apples become lemons and lemons become pineapples. Eating a dot awards 10 points and 1/16 of a powerball recharge; eating a pineapple is worth 160 points and 1/4 of a powerball recharge.
Players are additionally encouraged to inscribe sections of the playfield by the letters E, X, T, R, A, a constant feature of the Mr. Do! games. Randomly, one of the inscribed fruits will turn into a flashing letter spot, corresponding with the movement of the Alpha-Monster at the top of the screen. If Mr. Do! runs over this spot, the monster sporting that letter will release from the top of the screen with three blue henchmen (which resemble the three ghost-like monsters from the original Mr. Do!, and chase after Mr. Do. Defeating the Alpha-monster will lock in that letter, and once all 5 letters are earned, the player earns an extra life (as well as pro
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https://en.wikipedia.org/wiki/Jack%20Corliss
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John B. ("Jack") Corliss is a scientist who has worked in the fields of geology, oceanography, and the origins of life.
Corliss is a University of California, San Diego Alumnus, receiving his PhD from Scripps Institution of Oceanography in the 1960s. As part of his doctoral work under Jerry van Andel, he analyzed samples of basaltic rock from the Mid-Atlantic Ridge. Chemical traces in these rocks showed evidence of hot water circulation, suggesting the existence of undersea hot springs known as hydrothermal vents.
Following the completion of his PhD, Corliss became a researcher at Oregon State University. In 1977, Corliss, Richard von Herzen, and Robert Ballard lead a project using the DSV Alvin submersible to look for the presumed hydrothermal vents near the Galápagos Islands. Corliss, Tjeerd van Andel, and pilot Jack Donnelly were the crew of the Alvin to first discover the vents and the unexpected community of living creatures—giant tube worms, clams, shrimp, etc.—around them.
The discovery of the hydrothermal vent ecosystems caused Corliss to significantly shift his research, from geochemistry to the origins of life. He proposed that the earliest life on Earth began in deep sea vents. In 1981, he, John Baross, and Sarah Hoffman published a paper entitled "An Hypothesis Concerning the Relationship Between Submarine Hot Springs and the Origin of Life on Earth." In 1983, he moved to Budapest to continue working independently on this hypothesis.
In 1988, Corliss joined the NASA Goddard Space Flight Center's high-performance computing division. There he began using massively parallel computers (the Goodyear MPP and later MasPar MP-1) for cellular automata simulations of evolutionary systems.
In 1993, he became director of research at Biosphere 2 in Arizona.
He was hired to bring rigor and openness to the project, following conflicts that had resulted in the mass resignation of the project's scientific advisory board.
In 1996, he returned to Budapest to f
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https://en.wikipedia.org/wiki/Small-world%20routing
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In network theory, small-world routing refers to routing methods for small-world networks. Networks of this type are peculiar in that relatively short paths exist between any two nodes. Determining these paths, however, can be a difficult problem from the perspective of an individual routing node in the network if no further information is known about the network as a whole.
Greedy routing
Nearly every solution to the problem of routing in small world involves the application of greedy routing. This sort of routing depends on a relative reference point by which any node in the path can choose the next node it believes is closest to the destination. That is, there must be something to be greedy about. For example, this could be geographic location, IP address, etc. In the case of Milgram's original small-world experiment, participants knew the location and occupation of the final recipient and could therefore forward messages based on those parameters.
Constructing a reference base
Greedy routing will not readily work when there is no obvious reference base. This can occur, for example, in overlay networks where information about the destination's location in the underlying network is not available. Friend-to-friend networks are a particular example of this problem. In such networks, trust is ensured by the fact that you only know underlying information about nodes with whom you are already a neighbor.
One solution in this case, is to impose some sort of artificial addressing on the nodes in such a way that this addressing can be effectively used by greedy routing methods. A 2005 paper by a developer of the Freenet Project discusses how this can be accomplished in friend to friend networks. Given the assumption that these networks exhibit small world properties, often as the result of real-world or acquaintance relationships, it should be possible to recover an embedded Kleinberg small-world graph. This is accomplished by selecting random pairs of nodes and potent
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https://en.wikipedia.org/wiki/Circumferentor
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A circumferentor, or surveyor's compass, is an instrument used in surveying to measure horizontal angles. It was superseded by the theodolite in the early 19th century.
A circumferentor consists of a circular brass box containing a magnetic needle, which moves freely over a brass circle, or compass divided into 360 degrees. The needle is protected by a glass covering. A pair of sights is located on the North-South axis of the compass. Circumferentors were typically mounted on tripods and rotated on ball-and-socket joints.
Circumferentors were made throughout Europe, including in England, France, Italy, and Holland. By the early 19th century, Europeans preferred theodolites to circumferentors. However, the circumferentor remained in common use in mines and in wooded or uncleared areas, such as in America.
Usage
Measuring angles
To measure an angle with a circumferentor, such as angle EKG (Figure 1), place the instrument at K, with the fleur-de-lis in the card towards you. Then direct the sights, until through them you see E; and note the degree pointed at by the south end of the needle, such as 296°. Then, turn the instrument around, with the fleur-de-lis still towards you, and direct the sights to G; note the degree at which the south end of the needle point, such as 182°. Finally, subtract the lesser number, 182, from the greater, 296°; the remainder, 114°, is the number of degrees in the angle EKG.
If the remainder is more than 180 degrees, it must be subtracted from 360 degrees.
Surveying a region
To take the plot of a field, forest, park, etc., with a circumferentor, consider region ABCDEFGHK in Figure 2, an area to be surveyed.
Placing the instrument at A, the fleur-de-lis towards you, direct the sights to B; where suppose the south end of the needle cuts 191°; and the ditch, wall, or hedge, measuring with a Gunter's chain, contains 10 chains, 75 links.
Placing the instrument at B, direct the sights as before to C; the south end of the needle, e.g. wi
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https://en.wikipedia.org/wiki/SNADS
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SNADS or Systems Network Architecture Distribution Services is an "asynchronous
distribution service that can store data for delayed delivery."
SNADS uses SNA data links to allow messages and objects to be sent from system to system using the APPC protocol. It is a very robust service: once an object has been accepted by SNADS it will get to its destination. If the communication link is unavailable (down), the transmission will be held on the sending system until the link is available, at which time it is sent. If the transmission is interrupted, it will be resumed or re-sent once the communication problem is resolved.
SNADS is available on several IBM platforms, including IBM i, the AS/400 or System/38. Microsoft Exchange Server 5.5 Enterprise Edition includes a gateway called SNA Distribution Services (SNADS) Connector for communication with SNADS networks.
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https://en.wikipedia.org/wiki/Pentago
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Pentago is a two-player abstract strategy game invented by Tomas Flodén.
The game is played on a 6×6 board divided into four 3×3 sub-boards (or quadrants). Taking turns, the two players place a marble of their color (either black or white) onto an unoccupied space on the board, and then rotate one of the sub-boards by 90 degrees either clockwise or anti-clockwise. This is optional at the beginning of the game, up until every sub-board no longer has rotational symmetry, at which point it becomes mandatory (this is because until then, a player could rotate an empty sub-board or one with just a marble in the middle, either of which has no real effect). A player wins by getting five of their marbles in a vertical, horizontal, or diagonal row (either before or after the sub-board rotation in their move). If all 36 spaces on the board are occupied without a row of five being formed then the game is a draw.
There is also a 3-4 player version called Pentago XL. The board is made of 9 3×3 boards, and there are 4 colours (red, yellow, green and blue) instead of the basic 2.
MindtwisterUSA has the rights of developing and commercializing the product in North America.
The 6×6 version of Pentago has been strongly solved with the help of a Cray supercomputer at NERSC. With symmetries removed, there are 3,009,081,623,421,558 possible positions. If both sides play perfectly, the first player to move will always win the game.
Awards
Game of the Year 2005 in Sweden
Game of the Year 2006 in France
Award winner in Mensa Mind Games 2006 Review
So far Pentago has won 8 major awards, lastly Game of the Year 2007, by Creative Child Magazine.
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https://en.wikipedia.org/wiki/Unbundled%20network%20element
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Unbundled network elements (UNEs) are a requirement mandated by the United States Telecommunications Act of 1996. They are the parts of the telecommunications network that the incumbent local exchange carriers (ILECs) are required to offer on an unbundled basis. Together, these parts make up a local loop that connects to a digital subscriber line access multiplexer (DSLAM), a voice switch or both. The loop allows non-facilities-based telecommunications providers to deliver service without having to lay network infrastructure such as copper wire, optical fiber, and coaxial cable.
UNE-Platform
A UNE-Platform (or UNE-P) is a combination of UNEs that allow end-to-end service delivery without any facilities. Despite not involving any CLEC facilities, a UNE-P still requires facilities-based certification from the Public Utilities Commission to deliver services.
Availability
In Telecommunications Act of 1996 sections 251(c)(3), incumbent local exchange carriers (LECs) are required to lease certain parts of their network specified by the FCC or by state PUCs. According to section 252(d)(1), these network elements must be provided on an unbundled basis at cost-based rates.
FCC orders
In the UNE Remand Order issued on November 5, 1999, the FCC specified the UNE to which a competitor must be provided access: "the 'loops' that connect the switches to end users, including high-capacity loops; the switches (with some exceptions), the transport facilities between switches and other networks, and the software needed to operate the telephone network".
In the Line Sharing Orders (Line Sharing Order, 14 FCC Rcd at 20951), the LECs are required to unbundle the high-frequency portion of the loop of DSL.
However, both the UNE Remand Order and the Line Sharing Orders were remanded by the D.C. Circuit Court of Appeals in United States Telecom Association v. FCC (290 F.3d 415), decided on May 24, 2002; the Line Sharing Orders were vacated. The court concluded that the FCC had not consi
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https://en.wikipedia.org/wiki/Adductor%20tubercle%20of%20femur
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The adductor tubercle is a tubercle on the lower extremity of the femur. It is formed where the medial lips of the linea aspera end below at the summit of the medial condyle. It is the insertion point of the tendon of the vertical fibers of the adductor magnus muscle.
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https://en.wikipedia.org/wiki/Posterior%20scrotal%20nerves
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The posterior scrotal branches (in men) or posterior labial branches (in women) are two in number, medial and lateral. They are branches of the perineal nerve, which is itself a branch of the pudendal nerve. The pudendal nerve arises from spinal roots S2 through S4, travels through the pudendal canal on the fascia of the obturator internus muscle, and gives off the perineal nerve in the perineum. The major branch of the perineal nerve is the posterior scrotal/posterior labial.
They pierce the fascia of the urogenital diaphragm, and run forward along the lateral part of the urethral triangle in company with the posterior scrotal branches of the perineal artery; they are distributed to the skin of the scrotum or labia and communicate with the perineal branch of the posterior femoral cutaneous nerve.
See also
Anterior scrotal nerves
Anterior labial nerves
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https://en.wikipedia.org/wiki/Misalignment%20mechanism
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The misalignment mechanism is a hypothesized effect in the Peccei–Quinn theory proposed solution to the strong-CP problem in quantum mechanics. The effect occurs when a particle's field has an initial value that is not at or near a potential minimum. This causes the particle's field to oscillate around the nearest minimum, eventually dissipating energy by decaying into other particles until the minimum is attained.
In the case of hypothesized axions created in the early universe, the initial values are random because of the masslessness of axions in the high temperature plasma. Near the critical temperature of quantum chromodynamics, axions possess a temperature-dependent mass that enters a damped oscillation until the potential minimum is reached.
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https://en.wikipedia.org/wiki/3%20ft%20gauge%20rail%20modelling
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3' Gauge rail modelling is a specialisation in rail transport modelling. Specifically it relates to the modelling of narrow gauge prototypes of gauge. This gauge was the most common narrow gauge in the United States and in Ireland. Apart from some other lines in North, Central and South America, gauge was uncommon elsewhere. Therefore, most 3 ft gauge modellers model either United States or Irish prototypes.
United States
gauge railroads were widespread in the United States in the period 1880-90. While most of these railroads were converted to standard gauge by the start of the 20th century, a number of lines survived till the Second World War and later, and became popular subjects for modelling.
Probably the most popular prototype is the Denver and Rio Grande Western Railroad, followed by other Colorado railroads such as the Rio Grande Southern and Colorado and Southern. Other railroads from California and the eastern states are also popular.
Scale and gauge combinations used in modelling include:
Nn3 – Using N scale (1:160 ratio) with Z () gauge track.
HOn3 – Using HO scale (1:87 ratio) with gauge track. Historically the most popular of the scale/gauge combinations.
Sn3 – Using S scale (1:64 ratio) with gauge track. Limited commercial support.
On3 – Using O scale (1:48 ratio) with gauge track. Probably the second most popular scale.
F scale – using 1:20.3 ratio with gauge track. This scale uses the same gauge as, and is derived from the popular G scale. It is the largest popular scale/gauge combination, and is suitable for use in the garden.
Perhaps not surprisingly, most narrow gauge modellers in the United States model US gauge prototypes. However these prototypes are also popular modelling subjects outside the United States as well.
Ireland, the Isle of Man, and Britain
gauge was the narrow gauge used in Ireland, and the gauge of almost all the railways on the Isle of Man. It was also used on a handful of railways in Britain. However m
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https://en.wikipedia.org/wiki/Time%20to%20first%20byte
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Time to first byte (TTFB) is a measurement used as an indication of the responsiveness of a webserver or other network resource.
TTFB measures the duration from the user or client making an HTTP request to the first byte of the page being received by the client's browser. This time is made up of the socket connection time, the time taken to send the HTTP request, and the time taken to get the first byte of the page. Although sometimes misunderstood as a post-DNS calculation, the original calculation of TTFB in networking always includes network latency in measuring the time it takes for a resource to begin loading. Often, a smaller (faster) TTFB size is seen as a benchmark of a well-configured server application. For example, a lower time to first byte could point to fewer dynamic calculations being performed by the webserver, although this is often due to caching at either the DNS, server, or application level. More commonly, a very low TTFB is observed with statically served web pages, while larger TTFB is often seen with larger, dynamic data requests being pulled from a database.
Uses in web development
Time to first byte is important to a webpage since it indicates pages that load slowly due to server-side calculations that might be better served as client-side scripting. Often this includes simple scripts and calculations like transitioning images that are not gifs and are transitioned using JavaScript to modify their transparency levels. This can often speed up a website by downloading multiple smaller images through sockets instead of one large image. However this technique is more intensive on the client's computer and on older PCs can slow the webpage down when actually rendering.
Importance
TTFB is often used by web search engines like Google and Yahoo to improve search rankings since a website will respond to the request faster and be usable before other websites would be able to. There are downsides to this metric since a web-server can send only the
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https://en.wikipedia.org/wiki/Holt%E2%80%93Oram%20syndrome
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Holt–Oram syndrome (also called atrio-digital syndrome, atriodigital dysplasia, cardiac-limb syndrome, heart-hand syndrome type 1, HOS, ventriculo-radial syndrome) is an autosomal dominant disorder that affects bones in the arms and hands (the upper limbs) and often causes heart problems. The syndrome may include an absent radial bone in the forearm, an atrial septal defect in the heart, or heart block. It affects approximately 1 in 100,000 people.
Presentation
All people with Holt-Oram syndrome have, at least one, abnormal wrist bone, which can often only be detected by X-ray. Other bone abnormalities are associated with the syndrome. These vary widely in severity, and include a missing thumb, a thumb that looks like a finger, upper arm bones of unequal length or underdeveloped, partial or complete absence of bones in the forearm, and abnormalities in the collar bone or shoulder blade. Bone abnormalities may affect only one side of the body or both sides; if both sides are affected differently, the left side is usually affected more severely.
About 75 percent of individuals with Holt–Oram syndrome also have congenital heart problems, with the most common being defects in the tissue wall between the upper chambers of the heart (atrial septal defect) or the lower chambers of the heart (ventricular septal defect). People with Holt–Oram syndrome may also have abnormalities in the electrical system that coordinates contractions of the heart chambers. Cardiac conduction disease can lead to slow heart rate (bradycardia); rapid, ineffective contraction of the heart muscles (fibrillation); and heart block. People with Holt-Oram syndrome may have only congenital heart defects, only cardiac conduction disease, both or neither.
Genetics
Mutations in the TBX5 gene cause Holt–Oram syndrome. The TBX5 gene produces a protein that is critical for the proper development of the heart and upper limbs before birth.
Holt–Oram syndrome has an autosomal dominant pattern of inherita
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https://en.wikipedia.org/wiki/Bonner%20sphere
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A Bonner sphere is a device used to determine the energy spectrum of a neutron beam. The method was first described in 1960 by Rice University's Bramblett, Ewing and Tom W. Bonner and employs thermal neutron detectors embedded in moderating spheres of different sizes. Comparison of the neutrons detected by each sphere allows accurate determination of the neutron energy. This detector system utilizes a few channel unfolding techniques to determine the coarse, few group neutron spectrum. The original detector system was capable of measuring neutrons between thermal energies up to ~20 MeV. These detectors have been modified to provide additional resolution above 20 MeV to energies up to 1 GeV.
Bonner sphere spectroscopy
Because of the complexity with which neutrons interact with the environment, precise determination of the neutron energy is quite difficult. Bonner sphere spectroscopy (BSS) is one of the few methods that provide an accurate measure of the neutron spectrum.
Remball
A single Bonner sphere of an appropriate size can be used for dosimetry, as the sensitivity of the detector will approximate the radiation weighting factor across a range of neutron energies. Such Bonner spheres are sometimes known as a remball.
See also
Neutron detection
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https://en.wikipedia.org/wiki/Coprinopsis%20cinerea
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Coprinopsis cinerea is a species of mushroom in the family Psathyrellaceae. Commonly known as the gray shag, it is edible, but must be used promptly after collecting.
Coprinopsis cinerea is an important model organism for studying fungal sex and mating types, mushroom development, and the evolution of multicellularity of fungi. The genome sequence was published in 2010. It is considered to be particularly suited organism to study meiosis, due to its synchronous meiotic development and prolonged prophase.
Research
Antibiotics
Researchers in 2014 discovered a protein produced by Coprinopsis cinerea with antibiotic properties. The protein, known as copsin, has similar effects to other non-protein organically derived antibiotics. To date, it has not been determined whether antibiotic medicine for humans and other animals can be developed from this protein.
Culturing
Coprinopsis cinerea can be grown on complex (e.g. YMG, YMG/T) or minimal media (e.g. mKjalke medium), solid or liquid, with or without agitation, at 25 °C or optimally at 37 °C. It can be grown in dark or with 12-h light/12-h dark cycle.
Strains
C. cinereus strain PG78 (A6B42, trp1.1;1.6, pab1) is an AmutBmut monokaryon, self-compatible strain, with trp- and pab-auxotrophic markers (requires tryptophan and p-aminobenzoate).
Genome
Coprinopsis cinerea strain Okayama 7 (#130) was sequenced with 10x coverage in 2003. A third and most recent revision of the sequence of strain Okayama 7 (#130) was released in 2010. Its haploid genome is ca. 37.5 Mb.
Molecular cloning
Coprinopsis cinerea can be transformed with exogenous DNA by transformation when the fungus is a protoplast. It was found that disrupting (knockout or RNAi silencing) ku70 homologue can increase gene targeting via increased homologous recombination. Either protoplasts derived from oidia or vegetative mycelium can be used, however, gene targeting was found to be higher by 2% (based on phenotyping) when using vegetative mycelium. Otherwise, inse
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https://en.wikipedia.org/wiki/Action-angle%20coordinates
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In classical mechanics, action-angle variables are a set of canonical coordinates that are useful in characterizing the nature of commuting flows in integrable systems when the conserved energy level set is compact, and the commuting flows are complete. Action-angle variables are also important in obtaining the frequencies of oscillatory or rotational motion without solving the equations of motion. They only exist, providing a key characterization of the dynamics, when the system is completely integrable, i.e., the number of independent Poisson commuting invariants is maximal and the conserved energy surface is compact. This is usually of practical calculational value when the Hamilton–Jacobi equation is completely separable, and the separation constants can be solved for, as functions on the phase space. Action-angle variables define a foliation by invariant Lagrangian tori because the flows induced by the Poisson commuting invariants remain within their joint level sets, while the compactness of the energy level set implies they are tori. The angle variables provide coordinates on the leaves in which the commuting flows are linear.
The connection between classical Hamiltonian systems and their quantization in the Schrödinger wave mechanics approach is made clear by viewing the Hamilton-Jacobi equation as the leading order term in the WKB asymptotic series for the Schrodinger equation. In the case of integrable systems, the Bohr–Sommerfeld quantization conditions were first used,
before the advent of quantum mechanics, to compute the spectrum of the Hydrogen atom. They require that the action-angle variables exist, and that they be integral multiples of Planck's constant. Einstein's insight in the EBK quantization into the difficulty of quantizing non-integrable systems was based on this fact.
Action-angle coordinates are also useful in perturbation theory of Hamiltonian mechanics, especially in determining adiabatic invariants. One of the earliest results fro
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https://en.wikipedia.org/wiki/Bush%20tomato
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Bush tomatoes are the fruit or entire plants of certain nightshade (Solanum) species native to the more arid parts of Australia. While they are quite closely related to tomatoes (Solanum lycopersicum), they might be even closer relatives of the eggplant (S. melongena), which they resemble in many details. There are 94 (mostly perennial) natives and 31 (mostly annual) introduced species in Australia.
Bush tomato plants are small shrubs whose growth is encouraged by fire and disturbance.
The fruit of a number of species have been used as food sources by Aboriginal people in the drier areas of Australia.
A number of Solanum species contain significant levels of solanine and as such are highly poisonous. It is strongly recommended that people unfamiliar with the plant do not experiment with the different species, as differentiating between them can often be difficult.
Some of the edible species are:
Solanum aviculare kangaroo apple
Solanum centrale, also known as desert raisin, bush raisin or bush sultana, or by the native name kutjera
Solanum chippendalei bush tomato, named after taxonomic botanist George Chippendale
Solanum diversiflorum bush tomato, karlumbu, pilirta, wamurla
Solanum ellipticum potato bush, very similar to Solanum quadriloculatum which is poisonous.
Solanum laciniatum kangaroo apple.
Solanum orbiculatum round-leaved solanum
Solanum phlomoides wild tomato.
In 1859, aboriginal people were observed burning off the outer skin of S. aviculare as the raw state would blister their mouths. S. chippendalei is consumed by first splitting the fruit, scraping the centre out and eating the outer flesh as the seeds and surrounding placenta are bitter. S. diversiflorum is roasted before being eaten or dried. Fruit of S.orbiculatum is edible, but the fruit of the large leafed form may be bitter. Fruit of S. phlomoides appears to be edible after the removal of seeds and roasting or sundrying.
Solanum aviculare contains solasodine, a steroid used in t
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https://en.wikipedia.org/wiki/Acoustic%20shadow
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An acoustic shadow or sound shadow is an area through which sound waves fail to propagate, due to topographical obstructions or disruption of the waves via phenomena such as wind currents, buildings, or sound barriers.
Short-distance acoustic shadow
A short-distance acoustic shadow occurs behind a building or a sound barrier. The sound from a source is shielded by the obstruction. Due to diffraction around the object, it will not be completely silent in the sound shadow. The amplitude of the sound can be reduced considerably, however, depending on the additional distance the sound has to travel between source and receiver.
Long-distance acoustic shadow
Anomalous sound propagation in the atmosphere can occur in certain conditions of wind, temperature and pressure. Such conditions enable sound to travel in refraction channels over long distances until returning to the earth's surface, and it thus may not be heard in intervening locations. As one website refers to it, "an acoustic shadow is to sound what a mirage is to light". For example, at the Battle of Iuka, a northerly wind prevented General Ulysses S. Grant from hearing the sounds of battle and sending more troops. Many other instances of acoustic shadowing were prevalent during the American Civil War, including the Battles of Seven Pines, Gaines' Mill, Perryville and Five Forks. Indeed, this is addressed in the Ken Burns's documentary The Civil War, produced by Florentine Films and aired on PBS in September 1990. Observers of nearby battles would sometimes see the smoke and flashes of light from cannon but not hear the corresponding roar of battle, while those in more distant locations would hear the sounds distinctly.
Two diarists John Evelyn and Samuel Pepys heard from London the naval guns of the Four Days' Battle, which ranged over the southern North Sea between England and the Flanders coast. However the guns were not heard at all in towns on the coast nearer to the action:
Further reading
Garrison J
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https://en.wikipedia.org/wiki/Tubuloglomerular%20feedback
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In the physiology of the kidney, tubuloglomerular feedback (TGF) is a feedback system inside the kidneys. Within each nephron, information from the renal tubules (a downstream area of the tubular fluid) is signaled to the glomerulus (an upstream area). Tubuloglomerular feedback is one of several mechanisms the kidney uses to regulate glomerular filtration rate (GFR). It involves the concept of purinergic signaling, in which an increased distal tubular sodium chloride concentration causes a basolateral release of adenosine from the macula densa cells. This initiates a cascade of events that ultimately brings GFR to an appropriate level.
Background
The kidney maintains the electrolyte concentrations, osmolality, and acid-base balance of blood plasma within the narrow limits that are compatible with effective cellular function; and the kidney participates in blood pressure regulation and in the maintenance of steady whole-organism water volume
Fluid flow through the nephron must be kept within a narrow range for normal renal function in order to not compromise the ability of the nephron to maintain salt and water balance. Tubuloglomerular feedback (TGF) regulates tubular flow by detecting and correcting changes in GFR. Active transepithelial transport is used by the thick ascending limb of loop of Henle (TAL) cells to pump NaCl to the surrounding interstitium from luminal fluid. The tubular fluid is diluted because the cell's walls are water-impermeable and do not lose water as NaCl is actively reabsorbed. Thus, the TAL is an important segment of the TGF system, and its transport properties allow it to act as a key operator of the TGF system. A reduction of GFR occurs as a result of TGF when NaCl concentration at the sensor site is increased within the physiological range of approximately 10 to 60 mM.
The TGF mechanism is a negative feedback loop in which the chloride ion concentration is sensed downstream in the nephron by the macula densa (MD) cells in the tubula
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https://en.wikipedia.org/wiki/Hamaker%20theory
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After the explanation of van der Waals forces by Fritz London, several scientists soon realised that his definition could be extended from the interaction of two molecules with induced dipoles to macro-scale objects by summing all of the forces between the molecules in each of the bodies involved. The theory is named after H. C. Hamaker, who derived the interaction between two spheres, a sphere and a wall, and presented a general discussion in a heavily cited 1937 paper.
The interaction of two bodies is then treated as the pairwise interaction of a set of N molecules at positions: Ri {i:1,2,... ...,N}. The distance between the molecules i and j is then:
The interaction energy of the system is taken to be:
where is the interaction of molecules i and j in the absence of the influence of other molecules.
The theory is however only an approximation which assumes that the interactions can be treated independently, the theory must also be adjusted to take into account quantum perturbation theory.
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https://en.wikipedia.org/wiki/Comic%20Bakery
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Comic Bakery is a computer game for the MSX, made by Konami in 1984 and later a Commodore 64 conversion was made by Imagine Software.
Gameplay
The game is set in a bakery, where the town baker tries to bake and deliver bread (croissants in the MSX version) while fighting off raccoons. Pieces of bread move along a factory line while the raccoons try to eat the bread and switch off the machines. The player is required to keep the machinery running and also scare away the raccoons. If the player succeeds, the delivery truck is loaded with bread and drives off, advancing the player to the next level. Each level maintains the same format as the last, with the difficulty increasing as the player progresses through the levels.
Music
The music and sound effects for the C64 version were made by Martin Galway. The title chiptune has been covered by Press Play On Tape, Visa Röster, and Instant Remedy. The MSX version does not have unique music, using "Yankee Doodle" instead.
The C64 music has also been used as inspiration for the music in the games Jurassic Park (NES and Game Boy) and Platypus (PC).
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https://en.wikipedia.org/wiki/ScaLAPACK
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The ScaLAPACK (or Scalable LAPACK) library includes a subset of LAPACK routines redesigned for distributed memory MIMD parallel computers. It is currently written in a Single-Program-Multiple-Data style using explicit message passing for interprocessor communication. It assumes matrices are laid out in a two-dimensional block cyclic decomposition.
ScaLAPACK is designed for heterogeneous computing and is portable on any computer that supports MPI or PVM.
ScaLAPACK depends on PBLAS operations in the same way LAPACK depends on BLAS.
As of version 2.0 the code base directly includes PBLAS and BLACS and has dropped support for PVM.
Examples
Programming with Big Data in R fully utilizes ScaLAPACK and two-dimensional block cyclic decomposition for Big Data statistical analysis which is an extension to R.
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https://en.wikipedia.org/wiki/Inferior%20anal%20nerves
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The Inferior rectal nerves (inferior anal nerves, inferior hemorrhoidal nerve) usually branch from the pudendal nerve but occasionally arises directly from the sacral plexus; they cross the ischiorectal fossa along with the inferior rectal artery and veins, toward the anal canal and the lower end of the rectum, and is distributed to the Sphincter ani externus (external anal sphincter, EAS) and to the integument (skin) around the anus.
Branches of this nerve communicate with the perineal branch of the posterior femoral cutaneous and with the posterior scrotal nerves at the forepart of the perineum.
Supplies
Cutaneous innervation below the pectinate line and external anal sphincter.
See also
Inferior rectal artery
Additional images
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https://en.wikipedia.org/wiki/Algebraic%20operation
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In mathematics, a basic algebraic operation is any one of the common operations of elementary algebra, which include addition, subtraction, multiplication, division, raising to a whole number power, and taking roots (fractional power). These operations may be performed on numbers, in which case they are often called arithmetic operations. They may also be performed, in a similar way, on variables, algebraic expressions, and more generally, on elements of algebraic structures, such as groups and fields. An algebraic operation may also be defined simply as a function from a Cartesian power of a set to the same set.
The term algebraic operation may also be used for operations that may be defined by compounding basic algebraic operations, such as the dot product. In calculus and mathematical analysis, algebraic operation is also used for the operations that may be defined by purely algebraic methods. For example, exponentiation with an integer or rational exponent is an algebraic operation, but not the general exponentiation with a real or complex exponent. Also, the derivative is an operation that is not algebraic.
Notation
Multiplication symbols are usually omitted, and implied, when there is no operator between two variables or terms, or when a coefficient is used. For example, 3 × x2 is written as 3x2, and 2 × x × y is written as 2xy. Sometimes, multiplication symbols are replaced with either a dot or center-dot, so that x × y is written as either x . y or x · y. Plain text, programming languages, and calculators also use a single asterisk to represent the multiplication symbol, and it must be explicitly used; for example, 3x is written as 3 * x.
Rather than using the ambiguous division sign (÷), division is usually represented with a vinculum, a horizontal line, as in . In plain text and programming languages, a slash (also called a solidus) is used, e.g. 3 / (x + 1).
Exponents are usually formatted using superscripts, as in x2. In plain text, the TeX mark-up l
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https://en.wikipedia.org/wiki/Programming%20language%20specification
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In computer programming, a programming language specification (or standard or definition) is a documentation artifact that defines a programming language so that users and implementors can agree on what programs in that language mean. Specifications are typically detailed and formal, and primarily used by implementors, with users referring to them in case of ambiguity; the C++ specification is frequently cited by users, for instance, due to the complexity. Related documentation includes a programming language reference, which is intended expressly for users, and a programming language rationale, which explains why the specification is written as it is; these are typically more informal than a specification.
Standardization
Not all major programming languages have specifications, and languages can exist and be popular for decades without a specification. A language may have one or more implementations, whose behavior acts as a de facto standard, without this behavior being documented in a specification. Perl (through Perl 5) is a notable example of a language without a specification, while PHP was only specified in 2014, after being in use for 20 years. A language may be implemented and then specified, or specified and then implemented, or these may develop together, which is usual practice today. This is because implementations and specifications provide checks on each other: writing a specification requires precisely stating the behavior of an implementation, and implementation checks that a specification is possible, practical, and consistent. Writing a specification before an implementation has largely been avoided since ALGOL 68 (1968), due to unexpected difficulties in implementation when implementation is deferred. However, languages are still occasionally implemented and gain popularity without a formal specification: an implementation is essential for use, while a specification is desirable but not essential (informally, "code talks").
Forms
A programming
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https://en.wikipedia.org/wiki/Substitution%20%28logic%29
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A substitution is a syntactic transformation on formal expressions.
To apply a substitution to an expression means to consistently replace its variable, or placeholder, symbols with other expressions.
The resulting expression is called a substitution instance, or instance for short, of the original expression.
Propositional logic
Definition
Where ψ and φ represent formulas of propositional logic, ψ is a substitution instance of φ if and only if ψ may be obtained from φ by substituting formulas for symbols in φ, replacing each occurrence of the same symbol by an occurrence of the same formula. For example:
(R → S) & (T → S)
is a substitution instance of:
P & Q
and
(A ↔ A) ↔ (A ↔ A)
is a substitution instance of:
(A ↔ A)
In some deduction systems for propositional logic, a new expression (a proposition) may be entered on a line of a derivation if it is a substitution instance of a previous line of the derivation (Hunter 1971, p. 118). This is how new lines are introduced in some axiomatic systems. In systems that use rules of transformation, a rule may include the use of a substitution instance for the purpose of introducing certain variables into a derivation.
In first-order logic, every closed propositional formula that can be obtained from an open propositional formula φ by substitution is said to be a substitution instance of φ. If φ is a closed propositional formula we count φ itself as its only substitution instance.
Tautologies
A propositional formula is a tautology if it is true under every valuation (or interpretation) of its predicate symbols. If Φ is a tautology, and Θ is a substitution instance of Φ, then Θ is again a tautology. This fact implies the soundness of the deduction rule described in the previous section.
First-order logic
In first-order logic, a substitution is a total mapping from variables to terms; many, but not all authors additionally require σ(x) = x for all but finitely many variables x. The notation { x1 ↦ t1, …, xk ↦ t
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https://en.wikipedia.org/wiki/Georges%20Sagnac
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Georges Sagnac (; 14 October 1869 – 26 February 1928) was a French physicist who lent his name to the Sagnac effect, a phenomenon which is at the basis of interferometers and ring laser gyroscopes developed since the 1970s.
Life and work
Sagnac was born at Périgueux and entered the École Normale Supérieure in 1889. While a lab assistant at the Sorbonne, he was one of the first in France to study X-rays, following Wilhelm Conrad Röntgen. He belonged to a group of friends and scientists that notably included Pierre and Marie Curie, Paul Langevin, Jean Perrin, and the mathematician Émile Borel. Marie Curie says that she and her husband had traded ideas with Sagnac around the time of the discovery of radioactivity. Sagnac died at Meudon-Bellevue.
Sagnac effect
In 1913, Georges Sagnac showed that if a beam of light is split and sent in two opposite directions around a closed path on a revolving platform with mirrors on its perimeter, and then the beams are recombined, they will exhibit interference effects. From this result Sagnac concluded that light propagates at a speed independent of the speed of the source. The motion of the earth through space had no apparent effect on the speed of the light beam, no matter how the platform was turned. The effect had been observed earlier (by Harress in 1911), but Sagnac was the first to correctly identify the cause.
This Sagnac effect (in vacuum) had been theoretically predicted by Max von Laue in 1911. He showed that such an effect is consistent with stationary ether theories (such as the Lorentz ether theory) as well as with Einstein's theory of relativity. It is generally taken to be inconsistent with a complete ether drag; and also inconsistent with emission theories of light, according to which the speed of light depends on the speed of the source.
Sagnac was a staunch opponent of the theory of relativity, despite the Sagnac effect being consistent with it.
See also
Sagnac effect
History of special relativity#Experime
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https://en.wikipedia.org/wiki/Aliens%20vs.%20Predator%3A%20Requiem
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Aliens vs. Predator: Requiem (stylized as AVPR: Aliens vs. Predator – Requiem) is a 2007 American science fiction action film starring Steven Pasquale, Reiko Aylesworth, John Ortiz, Johnny Lewis and Ariel Gade. The directorial debut of The Brothers Strause, the film was written by Shane Salerno and is a direct sequel to Alien vs. Predator (2004) as well as the second and latest installment in the Alien vs. Predator franchise, the sixth film in the Alien franchise and the fourth film in the Predator franchise, continuing the crossover between the Alien and Predator franchises.
Set immediately after the events of the previous film, the film begins with a Predator ship crashing into a forest outside of Gunnison, Colorado, where an Alien-Predator hybrid known as the Predalien escapes and makes its way to the nearby small town. A skilled veteran "cleaner" Predator is dispatched to kill the Predalien, and the townspeople try to escape the ensuing carnage.
Aliens vs. Predator: Requiem premiered on November 4, 2007, in Los Angeles. It was released theatrically on December 25 in the United States. The film was panned by critics for its poor lighting, editing, and lack of originality. It grossed $130.2 million worldwide against a production budget of $40 million. Plans for another sequel were abandoned, with further independent entries in both franchises released in 2010 and 2012 respectively.
Plot
Following the events of the previous film, a Predator ship leaves Earth carrying Alien facehuggers and Scar's body before a chestburster with traits of both species emerges. It quickly matures into an adult Predalien and starts killing the Predators on board. The hull gets punctured and the ship crashes in a forest outside of Gunnison, Colorado, killing all but one of the Predators. The last surviving Predator sends a distress signal before being killed by the Predalien.
The Predalien and several facehuggers escape, implanting embryos into several humans. On the Predator homew
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https://en.wikipedia.org/wiki/Programming%20language%20implementation
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In computer programming, a programming language implementation is a system for executing computer programs. There are two general approaches to programming language implementation:
Interpretation: The program is read as input by an interpreter, which performs the actions written in the program.
Compilation: The program is read by a compiler, which translates it into some other language, such as bytecode or machine code. The translated code may either be directly executed by hardware, or serve as input to another interpreter or another compiler.
Interpreter
An interpreter is composed of two parts: a parser and an evaluator. After a program is read as input by an interpreter, it is processed by the parser. The parser breaks the program into language components to form a parse tree. The evaluator then uses the parse tree to execute the program.
Virtual machine
A virtual machine is a special type of interpreter that interprets bytecode. Bytecode is a portable low-level code similar to machine code, though it is generally executed on a virtual machine instead of a physical machine. To improve their efficiencies, many programming languages such as Java, Python, and C# are compiled to bytecode before being interpreted.
Just-in-time compiler
Some virtual machines include a just-in-time (JIT) compiler to improve the efficiency of bytecode execution. While the bytecode is being executed by the virtual machine, if the JIT compiler determines that a portion of the bytecode will be used repeatedly, it compiles that particular portion to machine code. The JIT compiler then stores the machine code in memory so that it can be used by the virtual machine. JIT compilers try to strike a balance between longer compilation time and faster execution time.
Compiler
A compiler translates a program written in one language into another language. Most compilers are organized into three stages: a front end, an optimizer, and a back end. The front end is responsible for understanding the
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https://en.wikipedia.org/wiki/Water%20hole%20%28radio%29
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The waterhole, or water hole, is an especially quiet band of the electromagnetic spectrum between 1420 and 1662 megahertz, corresponding to wavelengths of 21 and 18 centimeters, respectively. It is a popular observing frequency used by radio telescopes in radio astronomy.
The strongest hydroxyl radical spectral line radiates at 18 centimeters, and atomic hydrogen at 21 centimeters (the hydrogen line). These two molecules, which combine to form water, are widespread in interstellar gas, which means this gas tends to absorb radio noise at these frequencies. Therefore, the spectrum between these frequencies forms a relatively "quiet" channel in the interstellar radio noise background.
Bernard M. Oliver, who coined the term in 1971, theorized that the waterhole would be an obvious band for communication with extraterrestrial intelligence, hence the name, which is a pun: in English, a watering hole is a vernacular reference to a common place to meet and talk. Several programs involved in the search for extraterrestrial intelligence, including SETI@home, search in the waterhole radio frequencies.
See also
BLC1
Wow! signal
Radio source SHGb02+14a
Schelling point
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https://en.wikipedia.org/wiki/Frequency%20drift
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In electrical engineering, and particularly in telecommunications, frequency drift is an unintended and generally arbitrary offset of an oscillator from its nominal frequency. Causes may include component aging, changes in temperature that alter the piezoelectric effect in a crystal oscillator, or problems with a voltage regulator which controls the bias voltage to the oscillator. Frequency drift is traditionally measured in Hz/s. Frequency stability can be regarded as the absence (or a very low level) of frequency drift.
On a radio transmitter, frequency drift can cause a radio station to drift into an adjacent channel, causing illegal interference. Because of this, Frequency allocation regulations specify the allowed tolerance for such oscillators in a type-accepted device. A temperature-compensated, voltage-controlled crystal oscillator (TCVCXO) is normally used for frequency modulation.
On the receiver side, frequency drift was mainly a problem in early tuners, particularly for analog dial tuning, and especially on FM, which exhibits a capture effect. However, the use of a phase-locked loop (PLL) essentially eliminates the drift issue. For transmitters, a numerically controlled oscillator (NCO) also does not have problems with drift.
Drift differs from Doppler shift, which is a perceived difference in frequency due to motion of the source or receiver, even though the source is still producing the same wavelength. It also differs from frequency deviation, which is the inherent and necessary result of modulation in both FM and phase modulation.
See also
Allan variance
Clock drift
Phase noise
Automatic frequency control (AFC)
Phase-locked loop (PLL)
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https://en.wikipedia.org/wiki/Baire%20one%20star%20function
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A Baire one star function is a type of function studied in real analysis. A function is in class Baire* one, written , and is called a Baire one star function, if for each perfect set , there is an open interval , such that is nonempty, and the restriction is continuous. The notion seems to have originated with B. Kirchheim in an article titled 'Baire one star functions' (Real Anal. Exch. 18 (1992/93), 385-399).
The terminology is actually due to Richard O'Malley, 'Baire* 1, Darboux functions' Proc. Amer. Math. Soc. 60 (1976) 187-192. The concept itself (under a different name) goes back at least to 1951. See H. W. Ellis, 'Darboux properties and applications to nonabsolutely convergent integrals' Canad. Math. J., 3 (1951), 471-484, where the same concept is labelled as [CG] (for generalized continuity).
External links
A paper which defines class Baire* one
Real analysis
Types of functions
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https://en.wikipedia.org/wiki/Tapestry%20%28DHT%29
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Tapestry is a peer-to-peer overlay network which provides a distributed hash table, routing, and multicasting infrastructure for distributed applications. The Tapestry peer-to-peer system offers efficient, scalable, self-repairing, location-aware routing to nearby resources.
Introduction
The first generation of peer-to-peer applications, including Napster, Gnutella, had restricting limitations such as a central directory for Napster and scoped broadcast queries for Gnutella limiting scalability. To address these problems a second generation of P2P applications were developed including Tapestry, Chord, Pastry, and CAN. These overlays implement a basic key-based routing mechanism. This allows for deterministic routing of messages and adaptation to node failures in the overlay network. Of the named networks Pastry is very close to Tapestry as they both adopt the same routing algorithm by Plaxton et al.
Tapestry is an extensible infrastructure that provides decentralized object location and routing focusing on efficiency and minimizing message latency. This is achieved since Tapestry constructs locally optimal routing tables from initialization and maintains them in order to reduce routing stretch. Furthermore, Tapestry allows object distribution determination according to the needs of a given application. Similarly Tapestry allows applications to implement multicasting in the overlay network.
Algorithm
API
Each node is assigned a unique nodeID uniformly distributed in a large identifier space. Tapestry uses SHA-1 to produce a 160-bit identifier space represented by a 40 digit hex key.
Application specific endpoints GUIDs are similarly assigned unique identifiers. NodeIDs and GUIDs are roughly evenly distributed in the overlay network with each node storing several different IDs. From experiments it is shown that Tapestry efficiency increases with network size, so multiple applications sharing the same overlay network increases efficiency. To differentiate between
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https://en.wikipedia.org/wiki/Winlink
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Winlink, or formally, Winlink Global Radio Email (registered US Service Mark), also known as the Winlink 2000 Network, is a worldwide radio messaging system that uses amateur-band radio frequencies and government frequencies to provide radio interconnection services that include email with attachments, position reporting, weather bulletins, emergency and relief communications, and message relay. The system is built and administered by volunteers and is financially supported by the Amateur Radio Safety Foundation.
Network
Winlink networking started by providing interconnection services for amateur radio (also known as ham radio). It is well known for its central role in emergency and contingency communications worldwide. The system used to employ multiple central message servers around the world for redundancy, but in 2017–2018 upgraded to Amazon Web Services that provides a geographically-redundant cluster of virtual servers with dynamic load balancers and global content-distribution. Gateway stations have operated on sub-bands of HF since 2013 as the Winlink Hybrid Network, offering message forwarding and delivery through a mesh-like smart network whenever Internet connections are damaged or inoperable. During the late 1990s and late 2000s, it increasingly became what is now the standard network system for amateur radio email worldwide. Additionally, in response to the need for better disaster response communications in the mid to later part of the 2000s, the network was expanded to provide separate parallel radio email networking systems for MARS, UK Cadet, Austrian Red Cross, the US Department of Homeland Security SHARES HF Program, and other groups.
Amateur radio HF e-mail
Generally, e-mail communications over amateur radio in the 21st century is now considered normal and commonplace. E-mail via high frequency (HF) can be used nearly everywhere on the planet, and is made possible by connecting an HF single sideband (SSB) transceiver system to a computer, mod
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https://en.wikipedia.org/wiki/Petar%20V.%20Kokotovic
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Petar V. Kokotovic (Serbian Cyrillic: Петар В. Кокотовић) is professor emeritus in the College of Engineering at the University of California, Santa Barbara, USA. He has made contributions in the areas of adaptive control, singular perturbation techniques, and nonlinear control especially the backstepping stabilization method.
Biography
Kokotovic was born in Belgrade in 1934. He received his B.S. (1958) and M.S. (1963) degrees from the University of Belgrade Faculty of Electrical Engineering, and his Ph.D. (1965) from the USSR Academy of Sciences (Institute of Automation and Remote Control), Moscow.
He came to the United States in 1965 and was professor at the University of Illinois for 25 years. He joined the University of California, Santa Barbara, in 1991, where he was the founding and long-serving director of the Center for Control, Dynamical Systems and Computation. This center has become a role model of cross-disciplinary research and education. One of the Center’s achievements is a fully integrated cross-disciplinary graduate program for electrical and computer, mechanical and environmental, and chemical engineering fields.
At UC Santa Barbara his group developed constructive nonlinear control methods and applied them, with colleagues from MIT, Caltech and United Technologies Research Center, to new jet engine designs. As a long-term industrial consultant, he has contributed to computer controls at Ford and to power system stability at General Electric.
For his control systems contributions, Professor Kokotovic has been recognized with the triennial Quazza Medal from the International Federation of Automatic Control (IFAC), the Control Systems Field Award from the Institute of Electrical and Electronics Engineers (IEEE), and the 2002 Richard E. Bellman Control Heritage Award from the American Automatic Control Council, with the citation "for pioneering contributions to control theory and engineering, and for inspirational leadership as mentor, advisor, an
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https://en.wikipedia.org/wiki/Edmund%20Hlawka
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Edmund Hlawka (November 5, 1916, Bruck an der Mur, Styria – February 19, 2009) was an Austrian mathematician. He was a leading number theorist. Hlawka did most of his work at the Vienna University of Technology. He was also a visiting professor at Princeton University and the Sorbonne. Hlawka died on February 19, 2009, in Vienna.
Education and career
Hlawka studied at the University of Vienna from 1934 to 1938, when he gained his doctorate under Nikolaus Hofreiter. Among his PhD students were Rainer Burkard, later to become president of the Austrian Society for Operations Research, graph theorist Gert Sabidussi, Cole Prize winner Wolfgang M. Schmidt, Walter Knödel who became one of the first German computer science professors, and Hermann Maurer, also a computer scientist. Through these and other students, Hlawka has nearly 1500 academic descendants. Hlawka was awarded the Decoration for Services to the Republic of Austria in 2007.
Honours and awards
Decoration for Science and Art (Austria, 1963)
City of Vienna Prize for the Humanities (1969)
Decoration for Services to the Republic of Austria, Grand Decoration of Honour in Gold with Star (2007); Grand Decoration of Honour in Gold (1987)
Wilhelm Exner Medal (1982).
Joseph Johann Ritter von Prechtl Medal (1989)
Erwin Schrödinger Prize
See also
Minkowski–Hlawka theorem
Koksma–Hlawka inequality
10763 Hlawka, an asteroid named after Edmund Hlawka
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https://en.wikipedia.org/wiki/Range%20criterion
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In quantum mechanics, in particular quantum information, the Range criterion is a necessary condition that a state must satisfy in order to be separable. In other words, it is a separability criterion.
The result
Consider a quantum mechanical system composed of n subsystems. The state space H of such a system is the tensor product of those of the subsystems, i.e. .
For simplicity we will assume throughout that all relevant state spaces are finite-dimensional.
The criterion reads as follows: If ρ is a separable mixed state acting on H, then the range of ρ is spanned by a set of product vectors.
Proof
In general, if a matrix M is of the form , the range of M, Ran(M), is contained in the linear span of . On the other hand, we can also show lies in Ran(M), for all i. Assume without loss of generality i = 1. We can write
, where T is Hermitian and positive semidefinite. There are two possibilities:
1) spanKer(T). Clearly, in this case, Ran(M).
2) Notice 1) is true if and only if Ker(T) span, where denotes orthogonal complement. By Hermiticity of T, this is the same as Ran(T) span. So if 1) does not hold, the intersection Ran(T) span is nonempty, i.e. there exists some complex number α such that . So
Therefore lies in Ran(M).
Thus Ran(M) coincides with the linear span of . The range criterion is a special case of this fact.
A density matrix ρ acting on H is separable if and only if it can be written as
where is a (un-normalized) pure state on the j-th subsystem. This is also
But this is exactly the same form as M from above, with the vectorial product state replacing . It then immediately follows that the range of ρ is the linear span of these product states. This proves the criterion.
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https://en.wikipedia.org/wiki/Multiple%20rule-based%20problems
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Multiple rule-based problems are problems containing various conflicting rules and restrictions. Such problems typically have an "optimal" solution, found by striking a balance between the various restrictions, without directly defying any of the aforementioned restrictions.
Solutions to such problems can either require complex, non-linear thinking processes, or can instead require mathematics-based solutions in which an optimal solution is found by setting the various restrictions as equations, and finding an appropriate maximum value when all equations are added. These problems may thus require more working information as compared to causal relationship problem solving or single rule-based problem solving. The multiple rule-based problem solving is more likely to increase cognitive load than are the other two types of problem solving.
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https://en.wikipedia.org/wiki/Five-year%20survival%20rate
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The five-year survival rate is a type of survival rate for estimating the prognosis of a particular disease, normally calculated from the point of diagnosis. Lead time bias from earlier diagnosis can affect interpretation of the five-year survival rate.
There are absolute and relative survival rates, but the latter are more useful and commonly used.
Relative and absolute rates
Five-year relative survival rates are more commonly cited in cancer statistics. Five-year absolute survival rates may sometimes also be cited.
Five-year absolute survival rates describe the percentage of patients alive five years after the disease is diagnosed.
Five-year relative survival rates describe the percentage of patients with a disease alive five years after the disease is diagnosed, divided by the percentage of the general population of corresponding sex and age alive after five years. Typically, cancer five-year relative survival rates are well below 100%, reflecting excess mortality among cancer patients compared to the general population. In contrast to five-year absolute survival rates, five-year relative survival rates may also equal or even exceed 100% if cancer patients have the same or even higher survival rates than the general population. The pattern may occur if cancer patients can generally be cured, or patients diagnosed with cancer have greater socioeconomic wealth or access to medical care than the general population.
The fact that relative survival rates above 100% were estimated for some groups of patients appears counterintuitive on first view. It is unlikely that occurrence of prostate cancer would increase chances of survival, compared to the general population. A more plausible explanation is that the pattern reflects a selection effect of PSA screening, as screening tests tend to be used less often by socially disadvantaged population groups, who, in general, also have higher mortality.
Uses
Five-year survival rates can be used to compare the effectiven
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https://en.wikipedia.org/wiki/Atmospheric%20model
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In atmospheric science, an atmospheric model is a mathematical model constructed around the full set of primitive, dynamical equations which govern atmospheric motions. It can supplement these equations with parameterizations for turbulent diffusion, radiation, moist processes (clouds and precipitation), heat exchange, soil, vegetation, surface water, the kinematic effects of terrain, and convection. Most atmospheric models are numerical, i.e. they discretize equations of motion. They can predict microscale phenomena such as tornadoes and boundary layer eddies, sub-microscale turbulent flow over buildings, as well as synoptic and global flows. The horizontal domain of a model is either global, covering the entire Earth, or regional (limited-area), covering only part of the Earth. The different types of models run are thermotropic, barotropic, hydrostatic, and nonhydrostatic. Some of the model types make assumptions about the atmosphere which lengthens the time steps used and increases computational speed.
Forecasts are computed using mathematical equations for the physics and dynamics of the atmosphere. These equations are nonlinear and are impossible to solve exactly. Therefore, numerical methods obtain approximate solutions. Different models use different solution methods. Global models often use spectral methods for the horizontal dimensions and finite-difference methods for the vertical dimension, while regional models usually use finite-difference methods in all three dimensions. For specific locations, model output statistics use climate information, output from numerical weather prediction, and current surface weather observations to develop statistical relationships which account for model bias and resolution issues.
Types
The main assumption made by the thermotropic model is that while the magnitude of the thermal wind may change, its direction does not change with respect to height, and thus the baroclinicity in the atmosphere can be simulated usi
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https://en.wikipedia.org/wiki/Ventastega
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Ventastega (Venta referring to the Venta River at the Ketleri Formation where Ventastega was discovered) is an extinct genus of stem tetrapod that lived during the Upper Fammenian of the Late Devonian, approximately 372.2 to 358.9 million years ago. Only one species is known that belongs in the genus, Ventastega curonica, which was described in 1996 after fossils were discovered in 1933 and mistakenly associated with a fish called Polyplocodus wenjukovi. ‘Curonica’ in the species name refers to Curonia, the Latin name for Kurzeme, a region in western Latvia. Ventastega curonica was discovered in two localities in Latvia, and was the first stem tetrapod described in Latvia along with being only the 4th Devonian tetrapodomorph known at the time of description. Based on the morphology of both cranial and post-cranial elements discovered (see below), Ventastega is more primitive than other Devonian tetrapodomorphs including Acanthostega and Ichthyostega, and helps further understanding of the fish-tetrapod transition.
Discovery
Walter Gross was the first person to collect partial Ventastega remains, collecting some teeth in addition to scales from a locality called Ketleri in a Latvian Upper Famennian formation while on a collection trip in 1933. Gross attributed all remains to an osteolepiform fish named Polyplocodus wenjukov, before later in 1944 reattributing some of the fragments to a species called Panderichthys bystrowi when a piece of a lower jaw was collected from the same locality. Additional remains were collected from the locality and from another locality, Pavāri, in the same formation by researchers Per Erik Ahlberg, , and Oleg Lebedev. After this collection they realized the previously collected remains were assigned incorrectly, and were actually part of a newly discovered tetrapod, which they named and described in a paper published in 1996. In the follow years, several more fragments of Ventastega curonica remains have been discovered at both the Ketl
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https://en.wikipedia.org/wiki/Wolf%20reintroduction
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Wolf reintroduction involves the reintroduction of a portion of grey wolves in areas where native wolves have been extirpated. More than 30 subspecies of Canis lupus have been recognized, and grey wolves, as colloquially understood, comprise nondomestic/feral subspecies. Reintroduction is only considered where large tracts of suitable wilderness still exist and where certain prey species are abundant enough to support a predetermined wolf population.
United States
Arizona and New Mexico
The five last known wild Mexican gray wolves were captured in 1980 in accordance with an agreement between the United States and Mexico intended to save the critically endangered subspecies. Between 1982 and 1998, a comprehensive captive-breeding program brought Mexican wolves back from the brink of extinction. Over 300 captive Mexican wolves were part of the recovery program.
The ultimate goal for these wolves is to reintroduce them to areas of their former range. In March 1998, this reintroduction campaign began with the releasing of three packs into the Apache-Sitgreaves National Forest in Arizona, and 11 wolves into the Blue Range Wilderness Area of New Mexico. By 2014, as many as 100 wild Mexican wolves were in Arizona and New Mexico. The final goal for Mexican wolf recovery is a wild, self-sustaining population of at least 300 individuals. In 2021, 186 wolves were counted in the annual survey, of which 114 wolves were spotted in New Mexico and the other 72 in Arizona. This shows a steady growth throughout the last 5 years.
Current Distribution and Population
As of March 2023, there were at least 241 wild Mexican wolves in the United States: 136 in New Mexico (40 packs), and 105 in Arizona (19 packs). The total captive Mexican wolf population is 380 individuals, across over 60 facilities.
Colorado
Wolves traversed a Rocky Mountain pathway from Canada to Mexico until the 1940s. They are seen by wildlife experts as essential to the native balance of species, species intera
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https://en.wikipedia.org/wiki/Push%E2%80%93pull%20agricultural%20pest%20management
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Push–pull technology is an intercropping strategy for controlling agricultural pests by using repellent "push" plants and trap "pull" plants. For example, cereal crops like maize or sorghum are often infested by stem borers. Grasses planted around the perimeter of the crop attract and trap the pests, whereas other plants, like Desmodium, planted between the rows of maize, repel the pests and control the parasitic plant Striga. Push–pull technology was developed at the International Centre of Insect Physiology and Ecology (ICIPE) in Kenya in collaboration with Rothamsted Research, UK. and national partners. This technology has been taught to smallholder farmers through collaborations with universities, NGOs and national research organizations.
How push–pull works
Push–pull technology involves use of behaviour-modifying stimuli to manipulate the distribution and abundance of stemborers and beneficial insects for management of stemborer pests. It is based on in-depth understanding of chemical ecology, agrobiodiversity, plant-plant and insect-plant interactions, and involves intercropping a cereal crop with a repellent intercrop such as Desmodium uncinatum (silverleaf) (push), with an attractive trap plant such as Napier grass (pull) planted as a border crop around this intercrop. Gravid stemborer females are repelled from the main crop and are simultaneously attracted to the trap crop.
The push
The "push" in the intercropping scheme is provided by the plants that emit volatile chemicals (kairomones) which repel stemborer moths and drive them away from the main crop (maize or sorghum). The most commonly used species of push plants are legumes of the genus Desmodium (e.g. silverleaf Desmodium, D. uncinatum, and greenleaf Desmodium, D. intortum). The Desmodium is planted in between the rows of maize or sorghum, where they emit volatile chemicals (such as (E)-β-ocimene and (E)-4,8-dimethyl-1,3,7-nonatriene) that repel the stemborer moths. These semiochemicals are al
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https://en.wikipedia.org/wiki/Rakuten%20Advertising
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Rakuten Advertising, formerly known as Rakuten Marketing, is an affiliate marketing service provider. The company, in 2005, claimed it was the largest pay-for-performance affiliate marketing network on the Internet. In 2005, Rakuten acquired LinkShare for US$425 million in cash, making LinkShare a wholly owned U.S. division of Rakuten, Inc., a Japanese shopping portal. Rakuten LinkShare was re-branded to Rakuten Affiliate Network in 2014. In 2020, Rakuten Marketing was renamed as Rakuten Advertising.
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https://en.wikipedia.org/wiki/24%20%28puzzle%29
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The 24 puzzle is an arithmetical puzzle in which the objective is to find a way to manipulate four integers so that the end result is 24. For example, for the numbers 4, 7, 8, 8, a possible solution is .
The problem has been played as a card game in Shanghai since the 1960s, using playing cards. It has been known by other names, including Maths24. A proprietary version of the game has been created which extends the concept of the basic game to more complex mathematical operations.
Original version
The original version of 24 is played with an ordinary deck of playing cards with all the face cards removed. The aces are taken to have the value 1 and the basic game proceeds by having 4 cards dealt and the first player that can achieve the number 24 exactly using only allowed operations (addition, subtraction, multiplication, division, and parentheses) wins the hand. Some advanced players allow exponentiation, roots, logarithms, and other operations.
For short games of 24, once a hand is won, the cards go to the player that won. If everyone gives up, the cards are shuffled back into the deck. The game ends when the deck is exhausted, and the player with the most cards wins.
Longer games of 24 proceed by first dealing the cards out to the players, each of whom contributes to each set of cards exposed. A player who solves a set takes its cards and replenishes their pile, after the fashion of War. Players are eliminated when they no longer have any cards.
A slightly different version includes the face cards, Jack, Queen, and King, giving them the values 11, 12, and 13, respectively.
In the original version of the game played with a standard 52-card deck, there are four-card combinations.
Expansion to more complex operations
Additional operations, such as square root and factorial, allow more possible solutions to the game. For instance, a set of 1,1,1,1 would be impossible to solve with only the five basic operations. However, with the use of factorials, it is
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https://en.wikipedia.org/wiki/Terbium%28III%29%20oxide
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Terbium(III) oxide, also known as terbium sesquioxide, is a sesquioxide of the rare earth metal terbium, having chemical formula . It is a p-type semiconductor, which conducts protons, which is enhanced when doped with calcium. It may be prepared by the reduction of in hydrogen at 1300 °C for 24 hours.
It is a basic oxide and easily dissolved to dilute acids, and then almost colourless terbium salt is formed.
Tb2O3 + 6 H+ → 2 Tb3+ + 3 H2O
The crystal structure is cubic and the lattice constant is a = 1057 pm.
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https://en.wikipedia.org/wiki/Plena%20Ilustrita%20Vortaro%20de%20Esperanto
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Plena Ilustrita Vortaro de Esperanto (PIV; Complete Illustrated Dictionary of Esperanto) is a monolingual dictionary of the language Esperanto. It was first compiled in 1970 by a large team of Esperanto linguists and specialists under the guidance of Gaston Waringhien and is published by the Sennacieca Asocio Tutmonda (SAT). It may be consulted online for free.
The term "illustrated" refers to two features:
1 - The use of clipart-like symbols rather than abbreviations for certain purposes
(eg, entries pertaining to agriculture are marked with a small image of a sickle rather than a note like "Agri." for "Agrikulturo".)
2 - The occasional use of a line-art sketch illustrating the item being defined.
These sketches are not used for most entries.
The entries that do have a sketch are most commonly plants and animals, and sometimes tools.
History
Original publication
First published in 1970, the PIV has undergone two revisions to date and is considered by many to be something of a standard for Esperanto, thanks mainly to its unchallenged scope—15,200 words and 39,400 lexical units. However, it is also criticized as excessively influenced by the French language and politically biased. Moreover, its few and often outmoded illustrations appeared only as an appendix.
Supplement of 1987
In 1987, a supplement was separately published, produced under the guidance of Gaston Waringhien and Roland Levreaud. It covered approximately 1000 words and 1300 lexical units.
2002 and 2005 editions
In 2002, after many years of work, a new revised edition appeared with the title La Nova Plena Ilustrita Vortaro de Esperanto (The New PIV), also dubbed PIV2 or PIV2002. Its chief editor was Michel Duc-Goninaz. PIV2002 (much like PIV2005) includes 16,780 words and 46,890 lexical units. Its illustrations are no longer located on the last pages, but rather are incorporated into the text itself.
The edition was first presented to the SAT congress in Alicante, Spain in July 2002. The stock
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https://en.wikipedia.org/wiki/Poussin%20proof
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In number theory, the Poussin proof is the proof of an identity related to the fractional part of a ratio.
In 1838, Peter Gustav Lejeune Dirichlet proved an approximate formula for the average number of divisors of all the numbers from 1 to n:
where d represents the divisor function, and γ represents the Euler-Mascheroni constant.
In 1898, Charles Jean de la Vallée-Poussin proved that if a large number n is divided by all the primes up to n, then the average fraction by which the quotient falls short of the next whole number is γ:
where {x} represents the fractional part of x, and π represents the prime-counting function.
For example, if we divide 29 by 2, we get 14.5, which falls short of 15 by 0.5.
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https://en.wikipedia.org/wiki/Game%20accessibility
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Within the field of human–computer interaction, accessibility of video games is considered a sub-field of computer accessibility, which studies how software and computers can be made accessible to users with various types of impairments. It can also include tabletop RPGs, board games, and related products.
In spring 2020, the COVID-19 pandemic caused a massive boom of the video game industry. With an increasing number of people interested in playing video games and with video games increasingly being used for other purposes than entertainment, such as education, rehabilitation or health, game accessibility has become an emerging field of research, especially as players with disabilities could benefit from the opportunities video games offer the most. A 2010 study estimated that 2% of the U.S. population is unable to play a game at all because of an impairment and 9% can play games but suffers from a reduced gaming experience. A study conducted by casual games studio PopCap games found that an estimated one in five casual video gamers have a physical, mental or developmental disability. As games are increasingly used as education tools, there may be a legal obligation to make them accessible, as Section 508 of the Rehabilitation Act mandates that schools and universities that rely on federal funding must make their electronic and information technologies accessible. , the U.S. Federal Communications Commission (FCC) requires in-game communication between players on consoles to be accessible to players with sensory disabilities. In 2021, video game developers attempted to improve accessibility through every possible avenue. This includes reducing difficulty and enabling auto fire.
Outside of being used as education or rehabilitation tools video games are used as identification aspects leading disabled people to work much harder to attach additional meaning when gaming. This transforms the very nature of playing video games into a fight against a digitally divided c
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https://en.wikipedia.org/wiki/Current%20differencing%20buffered%20amplifier
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A current differencing buffered amplifier (CDBA) is a multi-terminal active component with two inputs and two outputs and developed by Cevdet Acar and Serdar Özoğuz. Its block diagram can be seen from the figure. It is derived from the current feedback amplifier (CFA).
Basic operation
The characteristic equation of this element can be given as:
,
,
.
Here, the current through the z-terminal follows the difference between the currents through p-terminal and n-terminal. Input terminals p and n are internally grounded. The difference of the input currents is converted into the output voltage Vw, therefore CDBA element can be considered as a special type of current feedback amplifier with differential current input and grounded y input.
The CDBA is simplifies the implementation, is free from parasitic capacitances, able to operate in the frequency range of more than hundreds of MHz (even GHz!), and suitable for current mode operation while, it also provides a voltage output.
Several voltage and current mode continuous-time filters, oscillators, analog multipliers, inductance simulators and a PID controller have been developed using this active element.
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https://en.wikipedia.org/wiki/Local%20field%20potential
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Local field potentials (LFP) are transient electrical signals generated in nerves and other tissues by the summed and synchronous electrical activity of the individual cells (e.g. neurons) in that tissue. LFP are "extracellular" signals, meaning that they are generated by transient imbalances in ion concentrations in the spaces outside the cells, that result from cellular electrical activity. LFP are 'local' because they are recorded by an electrode placed nearby the generating cells. As a result of the Inverse-square law, such electrodes can only 'see' potentials in spatially limited radius. They are 'potentials' because they are generated by the voltage that results from charge separation in the extracellular space. They are 'field' because those extracellular charge separations essentially create a local electric field. LFP are typically recorded with a high-impedance microelectrode placed in the midst of the population of cells generating it. They can be recorded, for example, via a microelectrode placed in the brain of a human or animal subject, or in an in vitro brain thin slice.
Background
During local field potential recordings, a signal is recorded using an extracellular microelectrode placed sufficiently far from individual local neurons to prevent any particular cell from dominating the electrophysiological signal. This signal is then low-pass filtered, cut off at ~300 Hz, to obtain the local field potential (LFP) that can be recorded electronically or displayed on an oscilloscope for analysis. The low impedance and positioning of the electrode allows the activity of a large number of neurons to contribute to the signal. The unfiltered signal reflects the sum of action potentials from cells within approximately 50-350 μm from the tip of the electrode and slower ionic events from within 0.5–3 mm from the tip of the electrode. The low-pass filter removes the spike component of the signal and passes the lower frequency signal, the LFP.
The voltmeter
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https://en.wikipedia.org/wiki/Spin%20pumping
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Spin pumping is the dynamical generation of pure spin current by the coherent precession of magnetic moments, which can efficiently inject spin from a magnetic material into an adjacent non-magnetic material. The non-magnetic material usually hosts the spin Hall effect that can convert the injected spin current into a charge voltage easy to detect. A spin pumping experiment typically requires electromagnetic irradiation to induce magnetic resonance, which converts energy and angular momenta from electromagnetic waves (usually microwaves) to magnetic dynamics and then to electrons, enabling the electronic detection of electromagnetic waves. The device operation of spin pumping can be regarded as the spintronic analog of a battery.
Spin pumping involves an AC effect and a DC effect:
The AC effect generates a spin current that oscillates at the same frequency with the microwave source.
The DC effect requires that the magnetic dynamic is circularly polarized or elliptically polarized, whereas a linear oscillation can only generate an AC component.
Both effects result in a net enhancement of the effective magnetic damping.
Spin pumping in ferromagnets
The spin current pumped into an adjacent layer by a precessing magnetic moment is given by
where is the spin current (the vector indicates the orientation of the spin, not the direction of the current), is the spin-mixing conductance characterizing the spin transparency of the interface, is the saturation magnetization, and is the time-dependent orientation of the moment.
Optical, microwave and electrical methods are also being explored. These devices could be used for low-power data transmission in spintronic devices or to transmit electrical signals through insulators.
Spin pumping in antiferromagnets
Spin pumping in antiferromagnetic materials does not vanish because the antiparallel magnetic moments contribute constructively rather than destructively to spin current, which was theoretically predicted in 2014
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