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https://en.wikipedia.org/wiki/Journal%20of%20Applied%20Physics | The Journal of Applied Physics is a peer-reviewed scientific journal with a focus on the physics of modern technology. The journal was originally established in 1931 under the name of Physics, and was published by the American Physical Society for its first 7 volumes. In January 1937, ownership was transferred to the American Institute of Physics "in line with the efforts of the American Physical Society to enhance the standing of physics as a profession". The journal's current editor-in-chief is André Anders (Leibniz Institute of Surface Engineering). According to the Journal Citation Reports, the journal has a 2022 impact factor of 3.2. |
https://en.wikipedia.org/wiki/Young%E2%80%93Laplace%20equation | In physics, the Young–Laplace equation () is an algebraic equation that describes the capillary pressure difference sustained across the interface between two static fluids, such as water and air, due to the phenomenon of surface tension or wall tension, although use of the latter is only applicable if assuming that the wall is very thin. The Young–Laplace equation relates the pressure difference to the shape of the surface or wall and it is fundamentally important in the study of static capillary surfaces. It's a statement of normal stress balance for static fluids meeting at an interface, where the interface is treated as a surface (zero thickness):
where is the Laplace pressure, the pressure difference across the fluid interface (the exterior pressure minus the interior pressure), is the surface tension (or wall tension), is the unit normal pointing out of the surface, is the mean curvature, and and are the principal radii of curvature. Note that only normal stress is considered, this is because it has been shown that a static interface is possible only in the absence of tangential stress.
The equation is named after Thomas Young, who developed the qualitative theory of surface tension in 1805, and Pierre-Simon Laplace who completed the mathematical description in the following year. It is sometimes also called the Young–Laplace–Gauss equation, as Carl Friedrich Gauss unified the work of Young and Laplace in 1830, deriving both the differential equation and boundary conditions using Johann Bernoulli's virtual work principles.
Soap films
If the pressure difference is zero, as in a soap film without gravity, the interface will assume the shape of a minimal surface.
Emulsions
The equation also explains the energy required to create an emulsion. To form the small, highly curved droplets of an emulsion, extra energy is required to overcome the large pressure that results from their small radius.
The Laplace pressure, which is greater for smaller droplets, |
https://en.wikipedia.org/wiki/Electronics%20Letters | Electronics Letters is a peer-reviewed scientific journal published biweekly by the Institution of Engineering and Technology. It specializes in the rapid publication of short communications on all areas of electronic engineering, including optical, communication, and biomedical engineering, as well as electronic circuits and signal processing.
In 2010 Electronics Letters was relaunched with a new section at the start of each issue. This section focuses on selected papers within the issue, providing expanded context and background to the research reported, through magazine-style news articles and interviews with the researchers behind the work. The articles are designed to be accessible to a general engineering audience and were made available free of charge, without a subscription, from the journal's website.
In 2013 a hybrid open-access model was introduced providing authors whose papers have been accepted for publication with an open access publication option.
History
In 1965, the British engineer and professor Peter Clarricoats, along with the association of Institution of Electrical Engineers, pioneered a peer-reviewed platform out of the necessity to quickly disseminate the latest researches in the field of electrical and electronic engineering. He became the first editor-in-chief of Electronics Letters. At present, professor Ian H. White, Head of Photonics Research at the University of Cambridge and professor Chris Toumazou of Imperial College London are the editors-in-chief of Electronics Letters. |
https://en.wikipedia.org/wiki/Journal%20of%20Physics%20B | The Journal of Physics B: Atomic, Molecular and Optical Physics is a biweekly peer-reviewed scientific journal published by IOP Publishing. It was established in 1968 from the division of the earlier title, Proceedings of the Physical Society. In 2006, the Journal of Optics B: Quantum and Semiclassical Optics was merged with the Journal of Physics B. The editor-in-chief is Marc Vrakking (Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy).
Scope
The journal covers research on atomic, molecular, and optical physics. Topics include atomic and molecular structure, spectra and collisions, ultracold matter, quantum optics and non linear optics, quantum information, laser physics, intense laser fields, ultrafast and x-ray physics and atomic and molecular physics in plasmas.
The journal publishes research papers, fast track communications, topical reviews, tutorials, and invited articles. It occasionally publishes special issues on developing research fields.
Abstracting and indexing
The journal is abstracted and indexed in:
See also
Journal of Physics |
https://en.wikipedia.org/wiki/Journal%20of%20Physics%20A | The Journal of Physics A: Mathematical and Theoretical is a peer-reviewed scientific journal published by IOP Publishing, the publishing branch of the Institute of Physics. It is part of the Journal of Physics series and covers theoretical physics focusing on sophisticated mathematical and computational techniques.
The journal is divided into six sections covering: statistical physics; chaotic and complex systems; mathematical physics; quantum mechanics and quantum information theory; classical and quantum field theory; fluid and plasma theory.
The editor in chief is Joseph A Minahan (Uppsala Universitet, Sweden). According to the Journal Citation Reports, the journal has a 2020 impact factor of 2.132.
History
Journal of Physics A was established in 1968 as one of the subdivisions of the earlier title, Proceedings of the Physical Society, established in 1874, the flagship journal of the Physical Society of London. The Physical Society later became the Institute of Physics, the current publisher of the journal. Its papers began being made available electronically in 1991; by 2002, its entire back archive had been digitised, as the first step in a larger project to digitise all of the Institute's publishing archives.
Indexing
The journal is indexed in:
Scopus
Inspec
Chemical Abstracts
GeoRef
INIS Atomindex
Astrophysics Data System
PASCAL
Referativny Zhurnal
Zentralblatt MATH
Science Citation Index and SciSearch
Current Contents/Physical, Chemical and Earth Sciences
See also
Journal of Physics: Condensed Matter |
https://en.wikipedia.org/wiki/ESAIM%3A%20Control%2C%20Optimisation%20and%20Calculus%20of%20Variations | ESAIM: Control, Optimisation and Calculus of Variations is a scientific journal in the field of applied mathematics.
External links
Mathematics journals
EDP Sciences academic journals |
https://en.wikipedia.org/wiki/Bivatuzumab%20mertansine | Bivatuzumab mertansine is a combination of bivatuzumab, a humanized monoclonal antibody, and mertansine, a cytotoxic agent. It is designed for the treatment of squamous cell carcinoma. |
https://en.wikipedia.org/wiki/Cantuzumab%20mertansine | Cantuzumab mertansine (SB-408075; huC242-DM1) is an antibody-drug conjugate investigated to treat colorectal cancer and other types of cancer. It is a humanized monoclonal antibody, cantuzumab (huC242) linked to a cytotoxic agent, mertansine (DM1). It was developed by ImmunoGen.
Mechanism
After the huC242 mab binds to the external domain of CanAg, the cantuzumab mertansine-CanAg complex is internalized, and the DM1 molecules are released intracellularly by cleavage of the DM1-huC242 disulfide bonds.
Clinical trials
Three phase I clinical studies had reported results by 2003. By 2005, clinical development had been suspended.
See also
Cantuzumab ravtansine |
https://en.wikipedia.org/wiki/Generalized%20assignment%20problem | In applied mathematics, the maximum generalized assignment problem is a problem in combinatorial optimization. This problem is a generalization of the assignment problem in which both tasks and agents have a size. Moreover, the size of each task might vary from one agent to the other.
This problem in its most general form is as follows: There are a number of agents and a number of tasks. Any agent can be assigned to perform any task, incurring some cost and profit that may vary depending on the agent-task assignment. Moreover, each agent has a budget and the sum of the costs of tasks assigned to it cannot exceed this budget. It is required to find an assignment in which all agents do not exceed their budget and total profit of the assignment is maximized.
In special cases
In the special case in which all the agents' budgets and all tasks' costs are equal to 1, this problem reduces to the assignment problem. When the costs and profits of all tasks do not vary between different agents, this problem reduces to the multiple knapsack problem. If there is a single agent, then, this problem reduces to the knapsack problem.
Explanation of definition
In the following, we have n kinds of items, through and m kinds of bins through . Each bin is associated with a budget . For a bin , each item has a profit and a weight . A solution is an assignment from items to bins. A feasible solution is a solution in which for each bin the total weight of assigned items is at most . The solution's profit is the sum of profits for each item-bin assignment. The goal is to find a maximum profit feasible solution.
Mathematically the generalized assignment problem can be formulated as an integer program:
Complexity
The generalized assignment problem is NP-hard, However, there are linear-programming relaxations which give a -approximation.
Greedy approximation algorithm
For the problem variant in which not every item must be assigned to a bin, there is a family of algorithms for s |
https://en.wikipedia.org/wiki/Patellar%20network | The patellar network (circulatory anastomosis around the knee-joint, patellar anastomosis, genicular anastomosis, articular vascular network of knee or rete articulare genus) is an intricate network of blood vessels around and above the patella, and on the contiguous ends of the femur and tibia, forming a superficial and a deep plexus.
The superficial plexus is situated between the fascia and skin around about the patella, and forms three well-defined arches: one, above the upper border of the patella, in the loose connective tissue over the quadriceps femoris; the other two, below the level of the patella, are situated in the fat behind the patellar ligament.
The deep plexus, which forms a close net-work of vessels, lies on the lower end of the femur and upper end of the tibia around their articular surfaces, and sends numerous offsets into the interior of the joint.
The genicular arteries which form this plexus are the medial inferior and medial superior genicular arteries, the lateral inferior and lateral superior genicular arteries, the descending genicular artery, the descending branch of lateral femoral circumflex artery, and the anterior tibial recurrent artery.
Clinical relevance
The genicular anastomosis provides collateral circulation to supply the leg when the knee is fully flexed.
When the knee suffers a popliteal aneurysm, if the femoral artery has to be ligated surgically, blood can still reach the popliteal artery distal to the ligation via the genicular anastomosis. However, if flow in the femoral artery of a normal leg is suddenly disrupted, blood flow distally is rarely sufficient. The reason for this is the fact that the genicular anastomosis is only present in a minority of individuals and is always undeveloped when disease in the femoral artery is absent.
Illustrations of the genicular anastomosis in textbooks all appear to have been derived from the idealized image, shown in the sidebox, produced first by Gray's Anatomy in 1910. Neither |
https://en.wikipedia.org/wiki/Fair%20computational%20tree%20logic | Fair computational tree logic is conventional computational tree logic studied with explicit fairness constraints.
Weak fairness / justice
This declares conditions such as all processes execute infinitely often. If you consider the processes to be Pi, then the condition becomes:
Strong fairness / compassion
Here, if a process is requesting a resource infinitely often (R), it should be allowed to get the resource (C) infinitely often:
Model checking for fair CTL
Consider a Kripke model with set of states F. A path is considered a fair path, if and
only if the path includes all members of F infinitely often.
Fair CTL model checking restricts the checks to only fair paths. There are two kinds of fair quantifiers:
1. Mf, si |= A if and only if holds in all fair paths.
2. Mf, si |= E if and only if holds in one or more fair paths.
A fair state is one from which at least one fair path originates. This translates to Mf, s |= EGtrue.
SCC-based approach
A strongly connected component (SCC) of a directed graph is a maximal strongly connected subgraph—all the nodes are reachable from each other. A fair SCC is one that has an edge into at least one node for each of the fair conditions.
To check for fair EG for any formula,
Compute what is called the denotation of the formula φ: the set of states such that M, s |= φ.
Restrict the model to the denotation.
Find the fair SCC.
Obtain the union of all 3 (above).
Compute the states that can reach the union.
Emerson Lei algorithm
The fix point characterization of Exist Globally is given by: [EGφ] = νZ .([φ] ∩ [EXZ ]), which is basically the limit applied according to Kleene's theorem. To fair paths, it becomes [Ef Gφ] = νZ .([φ] ∩Fi ∈FT [EX[E(Z U(Z ∧ Fi ))]), which means the formula holds in the current state and the next states and the next to next states until it meets all the members of the fair conditions. This means that, the condition is equivalent to a sort of accepting point where the accepting condition i |
https://en.wikipedia.org/wiki/Forging%20temperature | Forging temperature is the temperature at which a metal becomes substantially more soft, but is lower than the melting temperature, such that it can be reshaped by forging. Bringing a metal to its forging temperature allows the metal's shape to be changed by applying a relatively small force, without creating cracks. For most metals, forging temperature is approximately 70% of the absolute temperature (usually measured in kelvins) of its melting point.
Selecting the maximum forging temperature allows metals to be forged more easily, lowering the forging pressure and thus the wear on metal-forming dies. The temperature at which a metal is forged can affect the homogeneity in microstructure and mechanical properties of forged products, which can highly affect the performance of products used in manufacturing.
See also
Plasticity
Notes |
https://en.wikipedia.org/wiki/Square%20root%20of%203 | The square root of 3 is the positive real number that, when multiplied by itself, gives the number 3. It is denoted mathematically as or . It is more precisely called the principal square root of 3 to distinguish it from the negative number with the same property. The square root of 3 is an irrational number. It is also known as Theodorus' constant, after Theodorus of Cyrene, who proved its irrationality.
, its numerical value in decimal notation had been computed to at least ten billion digits. Its decimal expansion, written here to 65 decimal places, is given by :
The fraction (...) can be used as a good approximation. Despite having a denominator of only 56, it differs from the correct value by less than (approximately , with a relative error of ). The rounded value of is correct to within 0.01% of the actual value.
The fraction (...) is accurate to .
Archimedes reported a range for its value: .
The lower limit is an accurate approximation for to (six decimal places, relative error ) and the upper limit to (four decimal places, relative error ).
Expressions
It can be expressed as the continued fraction .
So it is true to say:
then when :
It can also be expressed by generalized continued fractions such as
which is evaluated at every second term.
Geometry and trigonometry
The square root of 3 can be found as the leg length of an equilateral triangle that encompasses a circle with a diameter of 1.
If an equilateral triangle with sides of length 1 is cut into two equal halves, by bisecting an internal angle across to make a right angle with one side, the right angle triangle's hypotenuse is length one, and the sides are of length and . From this, , , and .
The square root of 3 also appears in algebraic expressions for various other trigonometric constants, including the sines of 3°, 12°, 15°, 21°, 24°, 33°, 39°, 48°, 51°, 57°, 66°, 69°, 75°, 78°, 84°, and 87°.
It is the distance between parallel sides of a regular hexagon with sides of |
https://en.wikipedia.org/wiki/Cutaneous%20innervation | Cutaneous innervation refers to an area of the skin which is supplied by a specific cutaneous nerve.
Dermatomes are similar; however, a dermatome only specifies the area served by a spinal nerve. In some cases, the dermatome is less specific (when a spinal nerve is the source for more than one cutaneous nerve), and in other cases it is more specific (when a cutaneous nerve is derived from multiple spinal nerves.)
Modern texts are in agreement about which areas of the skin are served by which nerves, but there are minor variations in some of the details. The borders designated by the diagrams in the 1918 edition of Gray's Anatomy are similar, but not identical, to those generally accepted today.
Importance of the peripheral nervous system
The peripheral nervous system (PNS) is divided into the somatic nervous system, the autonomic nervous system, and the enteric nervous system. However, it is the somatic nervous system, responsible for body movement and the reception of external stimuli, which allows one to understand how cutaneous innervation is made possible by the action of specific sensory fibers located on the skin, as well as the distinct pathways they take to the central nervous system. The skin, which is part of the integumentary system, plays an important role in the somatic nervous system because it contains a range of nerve endings that react to heat and cold, touch, pressure, vibration, and tissue injury.
Importance of the central nervous system
The central nervous system (CNS) works with the peripheral nervous system in cutaneous innervation. The CNS is responsible for processing the information it receives from the cutaneous nerves that detect a given stimulus, and then identifying the kind of sensory inputs which project to a specific region of the primary somatosensory cortex.
The role of nerve endings on the surface of the skin
Groups of nerve terminals located in the different layers of the skin are categorized depending on whether the skin |
https://en.wikipedia.org/wiki/Pl%C3%BCcker%20matrix | The Plücker matrix is a special skew-symmetric 4 × 4 matrix, which characterizes a straight line in projective space. The matrix is defined by 6 Plücker coordinates with 4 degrees of freedom. It is named after the German mathematician Julius Plücker.
Definition
A straight line in space is defined by two distinct points and in homogeneous coordinates of the projective space. Its Plücker matrix is:
Where the skew-symmetric -matrix is defined by the 6 Plücker coordinates
with
Plücker coordinates fulfill the Grassmann–Plücker relations
and are defined up to scale. A Plücker matrix has only rank 2 and four degrees of freedom (just like lines in ). They are independent of a particular choice of the points and and can be seen as a generalization of the line equation i.e. of the cross product for both the intersection (meet) of two lines, as well as the joining line of two points in the projective plane.
Properties
The Plücker matrix allows us to express the following geometric operations as matrix-vector product:
Plane contains line:
is the point of intersection of the line and the plane ('Meet')
Point lies on line:
is the common plane , which contains both the point and the line ('Join').
Direction of a line: (Note: The latter can be interpreted as a plane orthogonal to the line passing through the coordinate origin)
Closest point to the origin
Uniqueness
Two arbitrary distinct points on the line can be written as a linear combination of and :
Their Plücker matrix is thus:
up to scale identical to .
Intersection with a plane
Let denote the plane with the equation
which does not contain the line . Then, the matrix-vector product with the Plücker matrix describes a point
which lies on the line because it is a linear combination of and . is also contained in the plane
and must therefore be their point of intersection.
In addition, the product of the Plücker matrix with a plane is the zero-vector, exactly if the line is contain |
https://en.wikipedia.org/wiki/Biology | Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary information encoded in genes, which can be transmitted to future generations. Another major theme is evolution, which explains the unity and diversity of life. Energy processing is also important to life as it allows organisms to move, grow, and reproduce. Finally, all organisms are able to regulate their own internal environments.
Biologists are able to study life at multiple levels of organization, from the molecular biology of a cell to the anatomy and physiology of plants and animals, and evolution of populations. Hence, there are multiple subdisciplines within biology, each defined by the nature of their research questions and the tools that they use. Like other scientists, biologists use the scientific method to make observations, pose questions, generate hypotheses, perform experiments, and form conclusions about the world around them.
Life on Earth, which emerged more than 3.7 billion years ago, is immensely diverse. Biologists have sought to study and classify the various forms of life, from prokaryotic organisms such as archaea and bacteria to eukaryotic organisms such as protists, fungi, plants, and animals. These various organisms contribute to the biodiversity of an ecosystem, where they play specialized roles in the cycling of nutrients and energy through their biophysical environment.
History
The earliest of roots of science, which included medicine, can be traced to ancient Egypt and Mesopotamia in around 3000 to 1200 BCE. Their contributions shaped ancient Greek natural philosophy. Ancient Greek philosophers such as Aristotle (384–322 BCE) contributed extensively to the development of biological knowledge. He explored biological causation and the diversity of life. His successor, Theophrastus, began the scienti |
https://en.wikipedia.org/wiki/Abstract%20model%20checking | In computer science and in mathematics, abstraction model checking is for systems where an actual representation is too complex in developing the model alone. So, the design undergoes a kind of translation to scaled down "abstract" version.
The set of variables are partitioned into visible and invisible depending on their change of values. The real state space is summarized into a smaller set of the visible ones.
Galois connected
The real and the abstract state spaces are Galois connected. This means that if we take an element from the abstract space, concretize it and abstract the concretized version, the result will be equal to the original. On the other hand, if you pick an element from the real space, abstract it and concretize the abstract version, the final result will be a super set of the original.
That is,
((abstract)) = abstract
((real)) real
See also |
https://en.wikipedia.org/wiki/Transverse%20Ligament%20of%20the%20Palmar%20Aponeurosis | The Transverse Ligament of the Palmar Aponeurosis (TLPA) is a thin band of transverse fibers of the distal portion of the palmar aponeurosis. It runs deep and transverse to the longitudinally oriented pretendinous bands of the palmar fascial complex, and serves as an attachment point for the septa of Legueu and Juvara.
The TLPA is also known as the "Ligament of Skoog". It should not be confused with the Natatory Ligament (also known as the "Superficial Transverse Metacarpal Ligament"), which runs parallel and distal to the TLPA, forming the webbing in between the bases of the fingers. |
https://en.wikipedia.org/wiki/Calcium%202-aminoethylphosphate | Calcium 2-aminoethylphosphate (Ca-AEP or Ca-2AEP) is a compound discovered by the biochemist Erwin Chargaff in 1941. It is the calcium salt of phosphorylethanolamine. It was patented by Hans Alfred Nieper and Franz Kohler.
Terminology and glossary
Calcium 2-amino ethyl phosphoric acid (Ca-AEP or Ca-2AEP) is also called calcium ethylamino-phosphate (calcium EAP), calcium colamine phosphate, calcium 2-aminoethyl ester of phosphoric acid, and calcium 2-amino ethanol phosphate
2-AEP plays a role as a component in the cell membrane and at the same time has the property to form complexes with minerals. This mineral transporter goes into the outer layer of the outer cell membrane where it releases its associated mineral and is itself metabolized with the structure of the cell membrane.
History, treatments, uses, and risks
Ca-AEP was discovered by Erwin Chargaff in 1953.
According to the U.S. National Multiple Sclerosis Society Calcium EAP is often promoted as a cure or therapy for Multiple Sclerosis and many other diseases. However, it states that it is not recommended by its medical advisory board, and also notes that the Food and Drug Administration has classified it as unsafe and unapproved for use.
Calcium 2-AEP is manufactured by numerous nutraceutical companies and is sold online and in health food stores. |
https://en.wikipedia.org/wiki/Paulo%20Ribenboim | Paulo Ribenboim (born March 13, 1928) is a Brazilian-Canadian mathematician who specializes in number theory.
Biography
Ribenboim was born into a Jewish family in Recife, Brazil. He received his BSc in mathematics from the University of São Paulo in 1948, and won a fellowship to study with Jean Dieudonné in France at the University of Nancy in the early 1950s, where he became a close friend of Alexander Grothendieck.
He has contributed to the theory of ideals and of valuations.
Ribenboim has authored 246 publications including 13 books. He has been at Queen's University in Kingston, Ontario, since the 1960s, where he remains a professor emeritus.
Jean Dieudonné was one of his doctoral advisors. Andrew Granville, Jan Minac, Karl Dilcher and Aron Simis have been a doctoral students of Ribenboim.
The Ribenboim Prize of the Canadian Number Theory Association is named in his honor.
Personal life
In 1951, Ribenboim married Huguette Demangelle, a French Catholic woman whom he met in France. The couple have two children and five grandchildren, and have lived in Canada since 1962.
Bibliography
Paulo Ribenboim (1964) Functions, Limits, and Continuity , John Wiley & Sons, Inc. |
https://en.wikipedia.org/wiki/Radar%20signal%20characteristics | A radar system uses a radio-frequency electromagnetic signal reflected from a target to determine information about that target. In any radar system, the signal transmitted and received will exhibit many of the characteristics described below.
In the time domain
The diagram below shows the characteristics of the transmitted signal in the time domain. Note that in this and in all the diagrams within this article, the x axis is exaggerated to make the explanation clearer.
Carrier
The carrier is an RF signal, typically of microwave frequencies, which is usually (but not always) modulated to allow the system to capture the required data. In simple ranging radars, the carrier will be pulse modulated and in continuous wave systems, such as Doppler radar, modulation may not be required. Most systems use pulse modulation, with or without other supplementary modulating signals. Note that with pulse modulation, the carrier is simply switched on and off in sync with the pulses; the modulating waveform does not actually exist in the transmitted signal and the envelope of the pulse waveform is extracted from the demodulated carrier in the receiver. Although obvious when described, this point is often missed when pulse transmissions are first studied, leading to misunderstandings about the nature of the signal.
Pulse width
The pulse width () (or pulse duration) of the transmitted signal is the time, typically in microseconds, each pulse lasts. If the pulse is not a perfect square wave, the time is typically measured between the 50% power levels of the rising and falling edges of the pulse.
The pulse width must be long enough to ensure that the radar emits sufficient energy so that the reflected pulse is detectable by its receiver. The amount of energy that can be delivered to a distant target is the product of two things; the peak output power of the transmitter, and the duration of the transmission. Therefore, pulse width constrains the maximum detection range of a t |
https://en.wikipedia.org/wiki/Gelfand%E2%80%93Mazur%20theorem | In operator theory, the Gelfand–Mazur theorem is a theorem named after Israel Gelfand and Stanisław Mazur which states that a Banach algebra with unit over the complex numbers in which every nonzero element is invertible is isometrically isomorphic to the complex numbers, i. e., the only complex Banach algebra that is a division algebra is the complex numbers C.
The theorem follows from the fact that the spectrum of any element of a complex Banach algebra is nonempty: for every element a of a complex Banach algebra A there is some complex number λ such that λ1 − a is not invertible. This is a consequence of the complex-analyticity of the resolvent function. By assumption, λ1 − a = 0. So a = λ · 1. This gives an isomorphism from A to C.
The theorem can be strengthened to the claim that there are (up to isomorphism) exactly three real Banach division algebras: the field of reals R, the field of complex numbers C, and the division algebra of quaternions H. This result was proved first by Stanisław Mazur alone, but it was published in France without a proof, when the author refused the editor's request to shorten his proof. Gelfand (independently) published a proof of the complex case a few years later. |
https://en.wikipedia.org/wiki/CRT%20%28genetics%29 | CRT is the gene cluster responsible for the biosynthesis of carotenoids. Those genes are found in eubacteria, in algae and are cryptic in Streptomyces griseus.
Role of CRT genes in carotenoid biosynthesis
The CRT gene cluster consists of twenty-five genes such as crtA, crtB, crtC, crtD, crtE, crtF, crtG, crtH, crtI, crtO, crtP, crtR, crtT, crtU, crtV, and crtY, crtZ. These genes play a role in varying stages of the Astaxanthin biosynthesis and Carotenoid biosynthesis (Table 1).
crtE encodes for an enzyme known as geranylgeranyl diphosphate synthase known to catalyze the condensation reaction of isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) into geranylgeranyl diphosphate (GGDP). Two GGDP molecules are subsequently converted into a single phytoene molecule by phytoene synthase, an enzyme encoded by crtB, known as PSY in Chlorophyta. The following desaturation of phytoene into ζ-carotene is catalyzed by the phytoene desaturase encoded by crtI, crtP, and/or PDS. ζ -carotene can also be obtained through phytoene using the carotene 2,4-desaturase enzyme (crtD). Depending on the species, varying carotenoids are accumulated following these steps.
Spirilloxanthin
Spirilloxanthin is obtained from lycopene following a hydration, desaturation, and methylation reaction. These reactions are catalyzed by carotene hydratase (crtC), carotene 3,4- desaturase (crtD), and carotene methyltransferase (crtF), respectively.
Canthaxanthin
Lycopene is cyclized through two enzymes lycopene cyclase and β-C-4-oxygenase/β-carotene ketolase encoded on the crtY (in Chlorophyta) /crtL (in cyanobacteria), and crtW, respectively. crtY cyclizes lycopene into β-carotene, which is subsequently oxygenated by crtW to form canthaxanthin.
Zeaxanthin and lutein
Zeaxanthin and lutein are obtained through hydroxylation of α- and β-carotene. Hydroxylation of Zeaxanthin occurs by β-carotene hydroxylase an enzyme encoded on the crtR (in cyanobacteria) and crtZ gene (in Chloroph |
https://en.wikipedia.org/wiki/Channel-state%20duality | In quantum information theory, the channel-state duality refers to the correspondence between quantum channels and quantum states (described by density matrices). Phrased differently, the duality is the isomorphism between completely positive maps (channels) from A to Cn×n, where A is a C*-algebra and Cn×n denotes the n×n complex entries, and positive linear functionals (states) on the tensor product
Details
Let H1 and H2 be (finite-dimensional) Hilbert spaces. The family of linear operators acting on Hi will be denoted by L(Hi). Consider two quantum systems, indexed by 1 and 2, whose states are density matrices in L(Hi) respectively. A quantum channel, in the Schrödinger picture, is a completely positive (CP for short), trace-preserving linear map
that takes a state of system 1 to a state of system 2. Next, we describe the dual state corresponding to Φ.
Let Ei j denote the matrix unit whose ij-th entry is 1 and zero elsewhere. The (operator) matrix
is called the Choi matrix of Φ. By Choi's theorem on completely positive maps, Φ is CP if and only if ρΦ is positive (semidefinite). One can view ρΦ as a density matrix, and therefore the state dual to Φ.
The duality between channels and states refers to the map
a linear bijection. This map is also called Jamiołkowski isomorphism or Choi–Jamiołkowski isomorphism.
Applications
This isomorphism is used to show that the "Prepare and Measure" Quantum Key Distribution (QKD) protocols, such as the BB84 protocol devised by C. H. Bennett and G. Brassard are equivalent to the "Entanglement-Based" QKD protocols, introduced by A. K. Ekert. More details on this can be found e.g. in the book Quantum Information Theory by M. Wilde. |
https://en.wikipedia.org/wiki/Government%20Secure%20Intranet | Government Secure Intranet (GSi) was a United Kingdom government wide area network, whose main purpose was to enable connected organisations to communicate electronically and securely at low protective marking levels. It was known for the '.gsi.gov.uk' family of domains for government email. Migration away from these domains began in 2019 and will be completed in 2023.
History
Use
Many UK government organisations used the GSi to transfer files on a peer-to-peer (P2P) basis between similarly accredited networks. The network itself was open within the context of its accreditation – it imposed no restrictions on traffic types carried across the network, restrictions and policy control were left to the connecting departments. Email traffic in and out of the network was filtered by an external provider.
Origin
The concept of GSi was defined by the Cabinet Office, and was turned into practical reality by the Internet Special Products group of Cable & Wireless (then known as Mercury Communications) at their Brentford premises. GSi development started late 1996, and can be roughly dated by checking the registration date of its first domain name, 'gsi.net', registered 30 May 1997. The formal go-live date was several months later (according to the Central Computer and Telecommunications Agency (CCTA) this was February 1998).
The main drivers behind the development of GSi was the plethora of inter-agency connections in UK government which made managing security and connectivity budgets problematic. GSi not only provided better oversight, it also normalised connectivity. GSi was designed as an accredited, dual link connected Internet Protocol backbone, it imposed no restrictions on what type of traffic it carried; any restrictions were considered a policy decision for each connecting department.
The design of GSi partly supported the then developing eGIF interoperability standards. This was a direct consequence of the two key technical people driving the project, one |
https://en.wikipedia.org/wiki/Six-bit%20character%20code | A six-bit character code is a character encoding designed for use on computers with word lengths a multiple of 6. Six bits can only encode 64 distinct characters, so these codes generally include only the upper-case letters, the numerals, some punctuation characters, and sometimes control characters. The 7-track magnetic tape format was developed to store data in such codes, along with an additional parity bit.
Types of six-bit codes
An early six-bit binary code was used for Braille, the reading system for the blind that was developed in the 1820s.
The earliest computers dealt with numeric data only, and made no provision for character data. Six-bit BCD, with several variants, was used by IBM on early computers such as the IBM 702 in 1953 and the IBM 704 in 1954. Six-bit encodings were replaced by the 8-bit EBCDIC code starting in 1964, when System/360 standardized on 8-bit bytes. There are some variants of this type of code (see below).
Six-bit character codes generally succeeded the five-bit Baudot code and preceded seven-bit ASCII.
Six-bit codes could encode more than 64 characters by the use of Shift Out and Shift In characters, essentially incorporating two distinct 62-character sets and switching between them. For example, the popular IBM 2741 communications terminal supported a variety of character sets of up to 88 printing characters plus control characters.
BCD six-bit code
Six-bit BCD code was the adaptation of the punched card code to binary code. IBM applied the terms binary-coded decimal and BCD to the variations of BCD alphamerics used in most early IBM computers, including the IBM 1620, IBM 1400 series, and non-decimal architecture members of the IBM 700/7000 series.
COBOL databases six-bit code
A six-bit code was also used in COBOL databases, where end-of-record information was stored separately.
Magnetic stripe card six-bit code
A six-bit code, with added odd parity bit, is used on Track 1 of magnetic stripe cards, as specified in ISO/IEC 78 |
https://en.wikipedia.org/wiki/Z%20curve | The Z curve (or Z-curve) method is a bioinformatics algorithm for genome analysis. The Z-curve is a three-dimensional curve that constitutes a unique representation of a DNA sequence, i.e., for the Z-curve and the given DNA sequence each can be uniquely reconstructed from the other.
The resulting curve has a zigzag shape, hence the name Z-curve.
Background
The Z Curve method was first created in 1994 as a way to visually map a DNA or RNA sequence. Different properties of the Z curve, such as its symmetry and periodicity can give unique information on the DNA sequence. The Z curve is generated from a series of nodes, P0, P1,...PN, with the coordinates xn, yn, and zn (n=0,1,2...N, with N being the length of the DNA sequence). The Z curve is created by connecting each of the nodes sequentially.
Applications
Information on the distribution of nucleotides in a DNA sequence can be determined from the Z curve. The four nucleotides are combined into six different categories. The nucleotides are placed into each category by some defining characteristic and each category is designated a letter.
The x, y, and z components of the Z curve display the distribution of each of these categories of bases for the DNA sequence being studied. The x-component represents the distribution of purines and pyrimidine bases (R/Y). The y-component shows the distribution of amino and keto bases (M/K) and the z-component shows the distribution of strong-H bond and weak-H bond bases (S/W) in the DNA sequence.
The Z-curve method has been used in many different areas of genome research, such as replication origin identification,, ab initio gene prediction,
isochore identification,
genomic island identification
and comparative genomics. Analysis of the Z curve has also been shown to be able to predict if a gene contains introns,
Research
Experiments have shown that the Z curve can be used to identify the replication origin in various organisms. One study analyzed the Z curve for multiple |
https://en.wikipedia.org/wiki/Eli%20Lilly%20%26%20Co.%20v.%20Medtronic%2C%20Inc. | Eli Lilly and Company v. Medtronic, Inc., 496 U.S. 661 (1990), is a United States Supreme Court case related to patent infringement in the medical device industry. It held that (e)(1) of United States patent law exempted premarketing activity conducted to gain approval of a device under the Federal Food, Drug, and Cosmetic Act from a finding of infringement.
See also
Medtronic, Inc. v. Lohr (1996)
Riegel v. Medtronic, Inc. (2008)
List of United States Supreme Court cases, volume 496 |
https://en.wikipedia.org/wiki/Advances%20in%20Applied%20Clifford%20Algebras | Advances in Applied Clifford Algebras is a peer-reviewed scientific journal that publishes original research papers and also notes, expository and survey articles, book reviews, reproduces abstracts and also reports on conferences and workshops in the area of Clifford algebras and their applications to other branches of mathematics and physics, and in certain cognate areas. There is a vibrant and interdisciplinary community around Clifford and Geometric Algebras with a wide range of applications. The main conferences in this subject include the The International Conference on Clifford Algebras and Their Applications in Mathematical Physics (ICCA) and Applications of Geometric Algebra in Computer Science and Engineering (AGACSE) series.
The journal was established in 1991 by Jaime Keller who was its editor-in-chief until his death in 2011. The second editor-in-chief of the journal was Waldyr Alves Rodrigues Jr. (Universidade Estadual de Campinas), and the current editor-in-chief is Uwe Kähler from University of Aveiro. The journal is published by Springer Science+Business Media under its Birkhäuser Verlag imprint. |
https://en.wikipedia.org/wiki/Sauce%20africaine | Sauce africaine is a brown sauce, flavoured with tomatoes, onions, peppers and herbs. It is derived from espagnole sauce (basic brown sauce), one of the five "mother sauces" of French cooking. This hearty sauce complements steak, chops, and chicken.
Though not as quickly prepared as some other sauces, its basic method is the same as most other derivatives of espagnole sauce. The tomatoes, onion and bell pepper are cooked with herbs such as basil, thyme and bay leaf), reduced in wine, then combined with the espagnole sauce.
See also
List of sauces |
https://en.wikipedia.org/wiki/Geodynamics | Geodynamics is a subfield of geophysics dealing with dynamics of the Earth. It applies physics, chemistry and mathematics to the understanding of how mantle convection leads to plate tectonics and geologic phenomena such as seafloor spreading, mountain building, volcanoes, earthquakes, faulting. It also attempts to probe the internal activity by measuring magnetic fields, gravity, and seismic waves, as well as the mineralogy of rocks and their isotopic composition. Methods of geodynamics are also applied to exploration of other planets.
Overview
Geodynamics is generally concerned with processes that move materials throughout the Earth. In the Earth's interior, movement happens when rocks melt or deform and flow in response to a stress field. This deformation may be brittle, elastic, or plastic, depending on the magnitude of the stress and the material's physical properties, especially the stress relaxation time scale. Rocks are structurally and compositionally heterogeneous and are subjected to variable stresses, so it is common to see different types of deformation in close spatial and temporal proximity. When working with geological timescales and lengths, it is convenient to use the continuous medium approximation and equilibrium stress fields to consider the average response to average stress.
Experts in geodynamics commonly use data from geodetic GPS, InSAR, and seismology, along with numerical models, to study the evolution of the Earth's lithosphere, mantle and core.
Work performed by geodynamicists may include:
Modeling brittle and ductile deformation of geologic materials
Predicting patterns of continental accretion and breakup of continents and supercontinents
Observing surface deformation and relaxation due to ice sheets and post-glacial rebound, and making related conjectures about the viscosity of the mantle
Finding and understanding the driving mechanisms behind plate tectonics.
Deformation of rocks
Rocks and other geological materials expe |
https://en.wikipedia.org/wiki/Axis%E2%80%93angle%20representation | In mathematics, the axis–angle representation parameterizes a rotation in a three-dimensional Euclidean space by two quantities: a unit vector indicating the direction (geometry) of an axis of rotation, and an angle of rotation describing the magnitude and sense (e.g., clockwise) of the rotation about the axis. Only two numbers, not three, are needed to define the direction of a unit vector rooted at the origin because the magnitude of is constrained. For example, the elevation and azimuth angles of suffice to locate it in any particular Cartesian coordinate frame.
By Rodrigues' rotation formula, the angle and axis determine a transformation that rotates three-dimensional vectors. The rotation occurs in the sense prescribed by the right-hand rule.
The rotation axis is sometimes called the Euler axis. The axis–angle representation is predicated on Euler's rotation theorem, which dictates that any rotation or sequence of rotations of a rigid body in a three-dimensional space is equivalent to a pure rotation about a single fixed axis.
It is one of many rotation formalisms in three dimensions.
Rotation vector
The axis–angle representation is equivalent to the more concise rotation vector, also called the Euler vector. In this case, both the rotation axis and the angle are represented by a vector codirectional with the rotation axis whose length is the rotation angle ,
It is used for the exponential and logarithm maps involving this representation.
Many rotation vectors correspond to the same rotation. In particular, a rotation vector of length , for any integer , encodes exactly the same rotation as a rotation vector of length . Thus, there are at least a countable infinity of rotation vectors corresponding to any rotation. Furthermore, all rotations by are the same as no rotation at all, so, for a given integer , all rotation vectors of length , in all directions, constitute a two-parameter uncountable infinity of rotation vectors encoding the same rotati |
https://en.wikipedia.org/wiki/Demethylase | Demethylases are enzymes that remove methyl (CH3) groups from nucleic acids, proteins (particularly histones), and other molecules. Demethylases are important epigenetic proteins, as they are responsible for transcriptional regulation of the genome by controlling the methylation of DNA and histones, and by extension, the chromatin state at specific gene loci.
Histone lysine demethylation
Histone methylation was initially considered an effectively irreversible process as the half-life of the histone methylation was approximately equal to the histone half-life. Histone lysine demethylase LSD1 (later classified as KDM1A) was first identified in 2004 as a nuclear amine oxidase homolog. Two main classes of histone lysine demethylases exist, defined by their mechanisms: flavin adenine dinucleotide (FAD)-dependent amine oxidases and α-ketoglutarate-dependent hydroxylases.
Histone lysine demethylases possess a variety of domains that are responsible for histone recognition, DNA binding, methylated amino acid substrate binding and catalytic activity. These include:
FAD-dependent amine oxidase domains containing the active catalytic site of KDM1
Jumonji-C domains containing the active catalytic site of KDM2 through KDM8
Jumonji-N domains responsible for Jumonji-C domain conformation stability
SWIRM (SWI3P, RSC8P and Moira) domains proposed as an anchor site for histone substrates and responsible for chromatin stability
PHD, CXXC and C5HC2 zinc finger domains responsible for histone recognition and binding
Histone lysine demethylases are classified according to their domains and unique substrate specificities. The lysine substrates and identified according to their position in the corresponding histone amino acid sequence and methylation state (for example, H3K9me3 refers to trimethylated histone 3 lysine 9.)
KDM1The KDM1 homologs include KDM1A and KDM1B. KDM1A demethylates H3K4me1/2 and H3K9me1/2, and KDM1B emethylates H3K4me1/2. KDM1 activity is critical to em |
https://en.wikipedia.org/wiki/Methylmalonyl-CoA | Methylmalonyl-CoA is the thioester consisting of coenzyme A linked to methylmalonic acid. It is an important intermediate in the biosynthesis of succinyl-CoA, which plays an essential role in the tricarboxylic acid cycle (aka the Citric Acid Cycle, or Krebs Cycle). The compound is sometimes referred to as "methylmalyl-CoA".
Biosynthesis and metabolism
Methylmalonyl-CoA results from the metabolism of fatty acid with an odd number of carbons, of ammino acids valine, isoleucine, methionine, threonine or of cholesterol side-chains, forming Propionyl-CoA. The latter is also formed from propionic acid, which bacteria produce in the intestine. Propionyl-CoA and bicarbonate are converted to Methylmalonyl-CoA by the enzyme propionyl-CoA Carboxylase. It then is converted into succinyl-CoA by methylmalonyl-CoA mutase (MUT). This reaction is a reversible isomerization. In this way, the compound enters the Citric Acid Cycle. The following diagram demonstrates the aforementioned reaction:
Propionyl CoA + Bicarbonate → Methylmalonyl CoA → Succinyl CoA
Vitamin B12
Vitamin B12 plays an integral role in this reaction. Coenzyme B12 (adenosyl-cobalamin) is an organometallic form of Vitamin B12 and serves as the cofactor of Methylmalonyl-CoA mutase, which is an essential enzyme in the human body. The transformation of Methylmalonyl-CoA to Succinyl-CoA by this enzyme is a radical reaction.
Related diseases
Methylmalonic Acidemia (MMA)
This disease occurs when methylmalonyl-CoA mutase is unable to isomerize sufficient amounts of methylmalonyl-CoA into succinyl-CoA. This causes a buildup of propionic and/or methylmalonic acid, which has effects on infants ranging from severe brain damage to death. The disease is linked to Vitamin B12, which is the metabolic precursor to methylmalonyl-CoA mutase.
Combined malonic and methylmalonic aciduria (CMAMMA)
In the metabolic disease combined malonic and methylmalonic aciduria (CMAMMA) due to ACSF3 deficiency, methylmalonyl-CoA synthetas |
https://en.wikipedia.org/wiki/Motilin%20receptor | Motilin receptor is a G protein-coupled receptor (previously GPCR38) that binds motilin. It was first cloned in 1999 by Merck Laboratories. and scientists have since been searching for compounds to modify its behavior.
The primary structure of the motilin receptor consists of 412 amino acids, while its tertiary structure resembles a golf club. The protein C-terminal protein protects from enzymatic degradation, while the N-terminal is essential for binding.
Function
The primary function of the motilin receptor is to contract gastric smooth muscle during phase III of the migrating motor complex (MMC). In this final phase of the MMC, N-type motilin receptors in the distal antral pump of the stomach are activated. This causes contraction of the gastric smooth muscle, sieving food into the small intestine, and priming the stomach for the next meal.
Motilin
Motilin is an intestinal peptide that stimulates the contraction of gastric smooth muscle via the motilin receptor. It is produced by enteroendocrine cells in the proximal small intestine and secreted cyclically. Motilin mimetics could be used to increase gastric motility in patients with gastroparesis e.g., constipation-predominant irritable bowel syndrome. However, none of the candidate drugs that have been tested so far have made it to market. |
https://en.wikipedia.org/wiki/Venturi%20Transport%20Protocol | Venturi Transport Protocol (VTP) is a patented proprietary transport layer protocol that is designed to transparently replace TCP in order to overcome inefficiencies in the design of TCP related to wireless data transport. It is owned by Venturi Wireless.
The protocol is employed by various wireless broadband internet service providers such as Verizon Wireless and Unwired (Unwired calls the Venturi Client application that provides transparent VTP connectivity the Unwired Optimizer) in order to speed up their network and to overcome latency issues.
External links
Venturi Wireless Solutions: Broadband Services - Optimization Technology
Unwired Optimizer FAQ
Internet protocols
Transport layer protocols
Wireless networking |
https://en.wikipedia.org/wiki/Robley%20Dunglison | Robley Dunglison (4 January 1798 – 1 April 1869) was an English-American physician, medical educator and author who served as the first full-time professor of medicine in the United States at the newly founded University of Virginia from 1824 to 1833. He authored multiple medical textbooks and is considered the "Father of American Physiology" after the publication of his landmark textbook Human Physiology in 1832. He was the personal physician to Thomas Jefferson, James Madison and James Monroe. He consulted in the treatment of Andrew Jackson and was in attendance at Jefferson's death.
He served as chair of materia medica, therapeutics, hygiene and medical jurisprudence at the University of Maryland School of Medicine from 1833 to 1836 and chair of the Institutes of Medicine and Medical Jurisprudence at Jefferson Medical College from 1836 to 1868. He assisted William Beaumont in some of his experiments on gastric digestion and published the first description of Huntington's disease in his textbook The Practice of Medicine in 1842.
Early life and education
Dunglison was born in Keswick, Cumbria, England to William and Elizabeth (Robley) Dunglison. His father was a textile manufacturer but died at the age of 35. His great-uncle was a Governor of British Tobago and it was planned for Robley to become a West Indies planter but the uncle died and the plans to move to the West Indies were abandoned. He began the study of medicine locally in 1814 and moved to London to complete his studies. He attended lectures at the University of Edinburgh and the Ecole de Medecine in Paris. In 1819, he received diplomas from the Royal College of Surgeons and the Society of Apothecaries and began the practice of medicine. He obtained his M. D. from the University of Erlangen, Germany, in 1823. He received his degree remotely by submitting a thesis (De Neuralgia) and a fee since the M.D. degree was not offered in London at the time.
Career
Dunglison initially focused on obstetrics and |
https://en.wikipedia.org/wiki/PX%20domain | The PX domain is a phosphoinositide-binding structural domain involved in targeting of proteins to cell membranes.
This domain was first found in P40phox and p47phox domains of NADPH oxidase (phox stands for phagocytic oxidase). It was also identified in many other proteins involved in membrane trafficking, including nexins, Phospholipase D, and phosphoinositide-3-kinases.
The PX domain is structurally conserved in eukaryotes, although amino acid sequences show little similarity. PX domains interact primarily with PtdIns(3)P lipids. However some of them bind to phosphatidic acid, PtdIns(3,4)P2, PtdIns(3,5)P2, PtdIns(4,5)P2, and PtdIns(3,4,5)P3. The PX-domain can also interact with other domains and proteins.
Human proteins containing this domain
Sorting nexins contain this domain. Other examples include:
HS1BP3
KIF16B (SNX23)
NCF1; NCF1C; NCF4; NISCH
PIK3C2A; PIK3C2B; PIK3C2G; PLD1; PLD2; PXK
RPS6KC1
SGK3; SH3PXD2A; SNAG1; SNX9 |
https://en.wikipedia.org/wiki/Mega%20Brands | Mega Brands Inc. (formerly Mega Bloks Inc. and Ritvik Holdings) is a Canadian children's toy company that is currently a wholly owned subsidiary of Mattel. Mega Bloks, a line of construction set toys, is its most popular product. Its other brands include Mega Construx, Mega Puzzles, Board Dudes and Rose Art. The company distributes a wide range of construction toys, puzzles, and craft-based products.
In 2016, Mega Brands' Bloks was second in worldwide sales (11%) of toy construction building sets.
History
Ritvik Holdings
In 1967, Victor Bertrand and his wife Rita founded the company as Ritvik Holdings (RH). Ritvik is a portmanteau word based on a combination of Rita and Victor. RH began by distributing toys made outside Canada and also facilitated contracts between foreign brands and Canadian manufacturers.
Ritvik later became a vertically integrated company as it expanded by adding plastic injection molding operations, design operations, tooling manufacturers, and marketing services. The company had a leading share of the plastic injection molded market by the early 1980s.
Wanting to expand beyond Canada, Victor Bertrand took an interest in construction block sets. He saw room for growth despite them being an industry staple since the early years of the 20th century when the Batima Block was released in Belgium in 1905. With Lego being the leading construction toy, Bertrand chose to make a similar set. Bertrand ignored friends and advisors, feeling he had two advantages in launching Mega Bloks: he aimed to produce jumbo-sized bricks for toddlers, who Lego bricks were not designed for, and he considered his expertise in injection molding would give him a price advantage.
At 1984 trade shows, Ritvik showed the Mega Bloks line in the US and Canada. An immediate hit, Mega Bloks had generally large sales in Canada, including a $1 million sale to Toys R Us, and were available almost anywhere in the two markets in 1985. Several multinational companies had made offer |
https://en.wikipedia.org/wiki/Two-dimensional%20singular-value%20decomposition | In linear algebra, two-dimensional singular-value decomposition (2DSVD) computes the low-rank approximation of a set of matrices such as 2D images or weather maps in a manner almost identical to SVD (singular-value decomposition) which computes the low-rank approximation of a single matrix (or a set of 1D vectors).
SVD
Let matrix contains the set of 1D vectors which have been centered. In PCA/SVD, we construct covariance matrix and Gram matrix
,
and compute their eigenvectors and . Since and we have
If we retain only principal eigenvectors in , this gives low-rank approximation of .
2DSVD
Here we deal with a set of 2D matrices . Suppose they are centered . We construct row–row and column–column covariance matrices
and
in exactly the same manner as in SVD, and compute their eigenvectors and . We approximate as
in identical fashion as in SVD. This gives a near optimal low-rank approximation of with the objective function
Error bounds similar to Eckard–Young theorem also exist.
2DSVD is mostly used in image compression and representation. |
https://en.wikipedia.org/wiki/Midblastula | In developmental biology, midblastula or midblastula transition (MBT) occurs during the blastula stage of embryonic development in non-mammals. During this stage, the embryo is referred to as a blastula. The series of changes to the blastula that characterize the midblastula transition include activation of zygotic gene transcription, slowing of the cell cycle, increased asynchrony in cell division, and an increase in cell motility.
Blastula Before MBT
Before the embryo undergoes the midblastula transition it is in a state of fast and constant replication of cells. The cell cycle is very short. The cells in the zygote are also replicating synchronously, always undergoing cell division at the same time. The zygote is not producing its own mRNA but rather it is using mRNAs that were produced in the mother and loaded into the oocyte in order to produce proteins necessary for zygotic growth. The zygotic DNA (genetic material) is not being used because it is repressed through a variety of mechanisms such as methylation. This repressed DNA is sometimes referred to as heterochromatin and is tightly packed together inside the cell because it is not being used for transcription.
Characteristics of the MBT
Before the zygote undergoes the midblastula transition it is in a state of fast and constant replication of cells.
Activation of Zygotic Gene Transcription
At this stage, the zygote starts producing its own mRNAs that are made from its own DNA, and no longer uses the maternal mRNA. This can also be called the maternal to zygotic transition. The maternal mRNAs are then degraded. Since the cells are now transcribing their own DNA, this stage is where expression of paternal genes is first observed.
Cell Cycle Changes
When the zygote begins to produce its own mRNA, the cell cycle begins to slow down and the G1 and G2 phases are added to the cell cycle. The addition of these phases allows the cell to have more time to proofread the new genetic material it is making to |
https://en.wikipedia.org/wiki/Lymphocyte%20function-associated%20antigen%201 | Lymphocyte function-associated antigen 1 (LFA-1) is an integrin found on lymphocytes and other leukocytes. LFA-1 plays a key role in emigration, which is the process by which leukocytes leave the bloodstream to enter the tissues. LFA-1 also mediates firm arrest of leukocytes. Additionally, LFA-1 is involved in the process of cytotoxic T cell mediated killing as well as antibody mediated killing by granulocytes and monocytes. As of 2007, LFA-1 has 6 known ligands: ICAM-1, ICAM-2, ICAM-3, ICAM-4, ICAM-5, and JAM-A. LFA-1/ICAM-1 interactions have recently been shown to stimulate signaling pathways that influence T cell differentiation. LFA-1 belongs to the integrin superfamily of adhesion molecules.
Structure
LFA-1 is a heterodimeric glycoprotein with non-covalently linked subunits. LFA-1 has two subunits designated as the alpha subunit and beta subunit. The alpha subunit was named aL in 1983. The alpha subunit is designated CD11a; and the beta subunit, unique to leukocytes, is beta-2 or CD18. The ICAM binding site is on the alpha subunit. The general binding region of the alpha subunit is the I-domain. Due to the presence of a divalent cation site in the I-domain, the specific binding site is often referred to as the metal-ion dependent adhesion site (MIDAS).
Activation
In an inactive state, LFA-1 rests in a bent conformation and has a low affinity for ICAM binding. This bent conformation conceals the MIDAS. Chemokines stimulate the activation process of LFA-1. The activation process begins with the activation of Rap1, an intracellular g-protein. Rap1 assists in breaking the constraint between the alpha and beta subunits of LFA-1. This induces an intermediate extended conformation. The conformational change stimulates a recruitment of proteins to form an activation complex. The activation complex further destabilizes the alpha and beta subunits. Chemokines also stimulate an I-like domain on the beta subunit, which causes the MIDAS site on the beta subunit to bind |
https://en.wikipedia.org/wiki/Proof%20sketch%20for%20G%C3%B6del%27s%20first%20incompleteness%20theorem | This article gives a sketch of a proof of Gödel's first incompleteness theorem. This theorem applies to any formal theory that satisfies certain technical hypotheses, which are discussed as needed during the sketch. We will assume for the remainder of the article that a fixed theory satisfying these hypotheses has been selected.
Throughout this article the word "number" refers to a natural number (including 0). The key property these numbers possess is that any natural number can be obtained by starting with the number 0 and adding 1 a finite number of times.
Hypotheses of the theory
Gödel's theorem applies to any formal theory that satisfies certain properties. Each formal theory has a signature that specifies the nonlogical symbols in the language of the theory. For simplicity, we will assume that the language of the theory is composed from the following collection of 15 (and only 15) symbols:
A constant symbol for zero.
A unary function symbol for the successor operation and two binary function symbols + and × for addition and multiplication.
Three symbols for logical conjunction, , disjunction, , and negation, ¬.
Two symbols for universal, , and existential, , quantifiers.
Two symbols for binary relations, = and <, for equality and order (less than).
Two symbols for left, and right, parentheses for establishing precedence of quantifiers.
A single variable symbol, and a distinguishing symbol that can be used to construct additional variables of the form x*, x**, x***, ...
This is the language of Peano arithmetic. A well-formed formula is a sequence of these symbols that is formed so as to have a well-defined reading as a mathematical formula. Thus is well formed while is not well formed. A theory is a set of well-formed formulas with no free variables.
A theory is consistent if there is no formula such that both and its negation are provable. ω-consistency is a stronger property than consistency. Suppose that is a formula with one fr |
https://en.wikipedia.org/wiki/Dopplergraph | A dopplergraph or dopplergram is a two-dimensional representation of the approaching and receding motions of an object or area.
The word "dopplergraph" is a combination of the words doppler and photograph. Dopplergraphs are two-dimensional records of variations in the doppler shift in light intensity.
Dopplergraphs do not need to be a record of the shift of visible light, but of any radiated wave, which includes electromagnetic waves and acoustic waves.
Because the doppler shift is caused by the velocity of the radiating source towards or away from the viewer, a dopplergraph is a picture of the velocities associated with the sources being viewed.
See also
Spectrogram
Spectroheliograph
Spectrohelioscope
Solar Dynamics Observatory |
https://en.wikipedia.org/wiki/Milman%E2%80%93Pettis%20theorem | In mathematics, the Milman–Pettis theorem states that every uniformly convex Banach space is reflexive.
The theorem was proved independently by D. Milman (1938) and B. J. Pettis (1939). S. Kakutani gave a different proof in 1939, and John R. Ringrose published a shorter proof in 1959.
Mahlon M. Day (1941) gave examples of reflexive Banach spaces which are not isomorphic to any uniformly convex space. |
https://en.wikipedia.org/wiki/Paralytic%20%28gene%29 | Paralytic is a gene in the fruit fly, Drosophila melanogaster, which encodes a voltage gated sodium channel within D. melanogaster neurons. This gene is essential for locomotive activity in the fly. There are 9 different para alleles, composed of a minimum of 26 exons within over 78kb of genomic DNA. The para gene undergoes alternative splicing to produce subtypes of the channel protein. Flies with mutant forms of paralytic are used in fly models of seizures, since seizures can be easily induced in these flies.
Gene
The para gene is located on the X chromosome within the Drosophila genome. There are 26 para exons, 13 are constitutively expressed in the transcript, while 15 are alternatively spliced. Alternative splicing allows for the formation of 60 unique transcripts and 57 unique polypeptides. The independent splicing of 11 exons allows for the unique cytoplasmic loops, the alternative splicing also can effect the Na+ channel kinetics, such as the varying gating conductivities. The mature mRNA transcript only includes one of C or D exonic region and only one of K or L exonic region, as they code for the same or similar regions. Neurons containing para exon L, show an increase in firing frequency which is associated with increase seizure susceptibility. Channel kinetics are influenced by splicing, that not only changes protein structure but can allow for varying modifications, like differential binding of cofactors.
Known mutant variants
Currently there are 117 known allele variants within the para locus, a few are mentioned below.
Protein
This proteins forms a sodium-selective ion channel, that relies on an electrochemical gradient. The protein consists of four homology domains, HD1, HD2, HD3 and HD4. Each homology domain has six alpha helical segments, S1-S6. The small alpha-helical region between S5 and S6 is known as the channel pore. Mutations within this region may be responsible for ion selectivity. The cytoplasmic loop between HD3 and HD4 is respons |
https://en.wikipedia.org/wiki/Tog%20%28unit%29 | The tog is a measure of thermal insulance of a unit area, also known as thermal resistance. It is commonly used in the textile industry and often seen quoted on, for example, duvets and carpet underlay.
The Shirley Institute in Manchester, England developed the tog as an easy-to-follow alternative to the SI unit of m2⋅K/W. The name comes from the informal word togs for 'clothing', which itself was probably derived from the word toga, a Roman garment. The backronym thermal overall grade is also attested.
The basic unit of insulation coefficient is the RSI, (1 m2⋅K/W). 1 tog = 0.1 RSI. There is also a US clothing unit, the clo, equivalent to 0.155 RSI or 1.55 tog, described in ASTM D-1518.
A tog is 0.1 m2⋅K/W. In other words, the thermal resistance in togs is equal to ten times the temperature difference (in °C) between the two surfaces of a material, when the flow of heat is equal to one watt per square metre.
British duvets are sold in steps of 1.5 tog from 3.0 tog (summer) to 16.5 tog (extra-warm). The stated values are a minimum; actual values may be up to 3 tog higher. Also, these values assume there is no added duvet cover that can trap air.
A few manufacturers have marketed combined duvet sets consisting of two duvets; one of approximately 4.5 tog and one of approximately 9.0 tog. These can be used individually as summer (4.5 tog) and spring/autumn (9.0 tog). When joined together using press studs around the edges, or Velcro strips across each of the corners, they become a 13.5 tog winter duvet and as such can be made to suit all seasons.
Testing
Launched in the 1940s by the Shirley Institute, the Shirley Togmeter is the standard apparatus for rating thermal resistance of textiles, commonly known as the Tog Test. This apparatus, described in BS 4745:2005, measures a sample of textile, either between two metal plates (for underclothing) or between a metal plate and free air (for outer layers). Each industry has its own specifications and methods for meas |
https://en.wikipedia.org/wiki/Universe%20at%20War%3A%20Earth%20Assault | Universe at War: Earth Assault is a real-time strategy game, developed by Petroglyph Games and published by Sega. Universe at War: Earth Assault was intended to be the first game in a planned series of games to be called the Universe at War series.
On May 10, 2007, Sega announced that the title was also in development for the Xbox 360, which was released in 2008. Further, on June 27, 2007, Sega announced that the title would allow cross platform multiplayer through Xbox Live and Games for Windows – Live services.
Plot
Universe at War: Earth Assault, begins during year 2012 when an alien race known as the Hierarchy lands on Earth to strip-mine the planet. Before this alien race has landed, observatories and scientists on Earth gave warning of aliens but the human race, as a whole, is not able to organize a unified military front against the alien forces. Because the Hierarchy has vast military experience from invading and destroying other planets in the universe, the human race is not able to withstand their forces.
The Novus (a race of machines who fight the Hierarchy to avenge their fallen creators) arrive just in time to save Washington, D.C. where the U.S. military has made its last stand. They then proceed to establish bases, using guerrilla tactics to harass the Hierarchy while investigating why the Hierarchy has delayed in using their ultimate weapon "the Purifier", to utterly eradicate all life on Earth and proceed to strip mine the planet. Over the course of these missions the Novus field commander Mirabel, a cloned member of Novus' creator species, manages to befriend the human General Moore, in charge of leading what's left of the US forces after the initial Hierarchy invasion, and together they are able to launch an attack on a Hierarchy Material Conduit and use it to enable Mirabel to board one of their command ships, learning that Kamal Re'x, the overseer in charge of the Hierarchy forces on Earth has purposefully delayed the Purifier's activation i |
https://en.wikipedia.org/wiki/Mathematical%20descriptions%20of%20the%20electromagnetic%20field | There are various mathematical descriptions of the electromagnetic field that are used in the study of electromagnetism, one of the four fundamental interactions of nature. In this article, several approaches are discussed, although the equations are in terms of electric and magnetic fields, potentials, and charges with currents, generally speaking.
Vector field approach
The most common description of the electromagnetic field uses two three-dimensional vector fields called the electric field and the magnetic field. These vector fields each have a value defined at every point of space and time and are thus often regarded as functions of the space and time coordinates. As such, they are often written as (electric field) and (magnetic field).
If only the electric field (E) is non-zero, and is constant in time, the field is said to be an electrostatic field. Similarly, if only the magnetic field (B) is non-zero and is constant in time, the field is said to be a magnetostatic field. However, if either the electric or magnetic field has a time-dependence, then both fields must be considered together as a coupled electromagnetic field using Maxwell's equations.
Maxwell's equations in the vector field approach
The behaviour of electric and magnetic fields, whether in cases of electrostatics, magnetostatics, or electrodynamics (electromagnetic fields), is governed by Maxwell-Heaviside's equations:
{| class="toccolours collapsible" width="400px" style="background-color:#ECFCF4; padding:6; cellpadding=6;text-align:left;border:2px solid #50C878"
|-
|text-align="center" colspan="2"|Maxwell's equations (vector fields)
|-
| || Gauss's law
|-
| || Gauss's law for magnetism
|-
| || Faraday's law
|-
| || Ampère–Maxwell law
|}
where ρ is the charge density, which can (and often does) depend on time and position, ε0 is the electric constant, μ0 is the magnetic constant, and J is the current per unit area, also a function of time and position. The equations |
https://en.wikipedia.org/wiki/First%20dorsal%20metatarsal%20artery | The first dorsal metatarsal artery is a small artery on the back of the foot. It runs forward on the first interosseous dorsalis muscle, and at the cleft between the great and second toes divides into two branches, one of which passes beneath the tendon of the extensor hallucis longus muscle, and is distributed to the medial border of the great toe; the other bifurcates to supply the adjoining sides of the great and second toes.
See also
Dorsal metatarsal arteries |
https://en.wikipedia.org/wiki/Plantar%20metatarsal%20veins | The plantar metatarsal veins run backward in the metatarsal spaces, collect blood from digital veins and communicate, by means of perforating veins, with the veins on the dorsum of the foot, and unite to form the deep plantar venous arch which lies alongside the plantar arterial arch. |
https://en.wikipedia.org/wiki/Repeater%20insertion | Repeater insertion is a technique used to reduce time delays associated with long wire lines in integrated circuits. This technique involves cutting the long wire into one or more shorter wires, and then inserting a repeater between each pair of newly created short wires.
The time it takes for a signal to travel from one end of a wire to the other end is known as wire-line delay or just delay. In an integrated circuit, this delay is characterized by RC, the resistance of the wire (R) multiplied by the wire's capacitance (C). Thus, if the wire's resistance is 100 ohms and its capacitance is 0.01 microfarad (μF), the wire's delay is one microsecond (µs).
To first order, the resistance of a wire on an integrated circuit is directly proportional, or linear, according to the wire's length. If a 1 mm length of the wire has 100 ohms resistance, then a 2 mm length will have 200 ohms resistance.
For the purposes of our highly simplified discussion, the capacitance of a wire also increases linearly along its length. If a 1 mm length of the wire has 0.01 µF capacitance, a 2 mm length of the wire will have 0.02 µF, a 3 mm wire will have 0.03 µF, and so o
Thus, the time delay through a wire increases with the square of the wire's length. This is true, to first order, for any wire whose cross-section remains constant along the length of the wire.
wire resistance capacitance time delay
length R C t
1 mm 100 ohm 0.01 µF 1 µs
2 mm 200 ohm 0.02 µF 4 µs
3 mm 300 ohm 0.03 µF 9 µs
The interesting consequence of this behavior is that, while a single 2 mm length of wire has a delay of 4 µs. Two separate 1 mm wires only have a delay of 1 µs each and cover the same distance in half the time. By cutting the wire in half, one can double its speed.
To make this science trick work properly, an active circuit must be placed between the two separate wires so as to move the signal from one to |
https://en.wikipedia.org/wiki/Dorsal%20digital%20veins%20of%20the%20foot | On the dorsum of the foot the dorsal digital veins receive, in the clefts between the toes, the intercapitular veins from the plantar venous arch and join to form short common digital veins. |
https://en.wikipedia.org/wiki/Toshiba%20TLCS | TLCS is a prefix applied to microcontrollers made by Toshiba. The product line includes multiple families of CISC and RISC architectures. Individual components generally have a part number beginning with "TMP". E.g. the TMP8048AP is a member of the TLCS-48 family.
TLCS-12
The TLCS-12 was a 12-bit microprocessor and central processing unit manufactured by Toshiba. It began development in 1971, and was completed in 1973. It was a 32mm² MOS integrated circuit chip with about 2,800 silicon gates, fabricated on a 6 µm process with NMOS logic. It was used in the Ford EEC engine control unit system, which began production in 1974 and went into mass production in 1975. The system memory included 512-bit RAM, 2kb ROM and 2kb EPROM.
TLCS-47 family
The microcontrollers in the TLCS-47 category are 4-bit systems. These are no longer advertised on the Toshiba website.
TLCS-48 family
The TLCS-48 family were clones of the Intel MCS-48 (8048) microcontroller.
TLCS-Z80 family
These were a series of Zilog Z80 compatible microcontrollers.
TLCS-90 family
The microcontrollers in the TLCS-90 family use a 8-bit/16-bit architecture reminiscent of the Z80. These are no longer advertised on the Toshiba website.
The TLCS-90 inherits most Z80 features, such as:
seven 8-bit registers (A, B, C, D, E, H and L),
six 16-bit registers (BC, DE, HL, IX, IY, and SP), three of which are 8-bit register pairs,
the combined parity/overflow flag,
the , and 16-bit exchange instructions, and
the and memory copy instructions.
There are, however, significant differences. It omits the separate I/O address space of the Z80, but adds more flexibility to operand combinations, some new operations (notably multiply and divide), and several additional addressing modes:
and indexed modes operating similarly to and
single-byte "zero page" addressing of memory from FF00–FFFF16
and addressing without a displacement, enabling a single byte of machine code to be saved and the execution time |
https://en.wikipedia.org/wiki/Cluster%20Computing%20%28journal%29 | Cluster Computing: the Journal of Networks, Software Tools and Applications is a peer-reviewed scientific journal on parallel processing, distributed computing systems, and computer communication networks. The journal was established in 1998.
According to the Journal Citation Reports, the journal had a 2020 impact factor of 1.809. The editor-in-chief is Salim Hariri (University of Arizona). |
https://en.wikipedia.org/wiki/Wavefront%20curvature%20sensor | A wavefront curvature sensor is a device for measuring the aberrations of an optical wavefront. Like a Shack–Hartmann wavefront sensor it uses an array of small lenses (or lenslets) to focus the wavefront into an array of spots. Unlike the Shack-Hartmann, which measures the position of the spots, the curvature sensor measures the intensity on either side of the focal plane. If a wavefront has a phase curvature, it will alter the position of the focal spot along the axis of the beam, thus by measuring the relative intensities in two places the curvature can be deduced.
See also
Adaptive optics
Wavefront sensor
Sources
Sensors
Optical instruments
Optical metrology |
https://en.wikipedia.org/wiki/Language%20deprivation%20experiments | Language deprivation experiments have been claimed to have been attempted at least four times through history, isolating infants from the normal use of spoken or signed language in an attempt to discover the fundamental character of human nature or the origin of language.
The American literary scholar Roger Shattuck called this kind of research study the "forbidden experiment" because of the exceptional deprivation of ordinary human contact it requires. Although not designed to study language, similar experiments on non-human primates (labelled the "pit of despair") utilising complete social deprivation resulted in serious psychological disturbances.
In history
An early record of a study of this kind can be found in Herodotus's Histories. According to Herodotus (ca. 485 – 425 BC), the Egyptian pharaoh Psamtik I (664 – 610 BC) carried out such a study, and concluded the Phrygian race must antedate the Egyptians since the child had first spoken something similar to the Phrygian word , meaning "bread". Recent researchers suggest this was likely a willful interpretation of their babbling.
An experiment allegedly carried out by Holy Roman Emperor Frederick II in the 13th century saw young infants raised without human interaction in an attempt to determine if there was a natural language that they might demonstrate once their voices matured. It is claimed he was seeking to discover what language would have been imparted into Adam and Eve by God. The experiments were recorded by the monk Salimbene di Adam in his Chronicles, who was generally extremely negative about Fredrick II (portraying his calamities as parallel to the Biblical plagues in The Twelve Calamities of Emperor Frederick II) and wrote that Frederick encouraged "foster-mothers and nurses to suckle and bathe and wash the children, but in no ways to prattle or speak with them; for he would have learnt whether they would speak the Hebrew language (which he took to have been the first), or Greek, or Latin, or A |
https://en.wikipedia.org/wiki/Virtual%20microscopy | Virtual microscopy is a method of posting microscope images on, and transmitting them over, computer networks. This allows independent viewing of images by large numbers of people in diverse locations. It involves a synthesis of microscopy technologies and digital technologies. The use of virtual microscopes can transform traditional teaching methods by removing the reliance on physical space, equipment, and specimens to a model that is solely dependent upon computer-internet access. This increases the convenience of accessing the slide sets and making the slides available to a broader audience. Digitized slides can have a high resolution and are resistant to being damaged or broken over time.
Prior to recent advances in virtual microscopy, slides were commonly digitized by various forms of film scanner and image resolutions rarely exceeded 5000 dpi. Nowadays, it is possible to achieve more than 100,000 dpi and thus resolutions approaching that visible under the optical microscope. This increase in scanning resolution comes at a price; whereas a typical flatbed or film scanner ranges in cost from $200 to $600, a 100,000 dpi slide scanner will range from $80,000 to $200,000.
See also
Digital pathology
Microscopy
Telepathology
Tissue Cytometry, a technique that brings the concept of flow cytometry to tissue section, in situ, and helps to perform whole slide scanning and quantification of markers by maintaining the spatial context. |
https://en.wikipedia.org/wiki/PME%20Aggregation%20Function | PME Aggregation Function (PAF) is a computer networking mechanism defined in Clause 61 of the IEEE 802.3 standard, which allows one or more Physical Medium Entities (PMEs) to be combined to form a single logical Ethernet link.
The PAF is located in the physical coding sublayer (PCS), between the media access control (MAC)-PHY Rate Matching function and the Transmission Convergence (TC) sublayer. It interfaces with the PMEs across the λ-interface, and to the MAC-PHY Rate Matching function using an abstract interface.
PAF is an optional function that was defined before 2007 for two IEEE 802.3 interfaces: 2BASE-TL and 10PASS-TS, both of which were Ethernet in the First Mile (EFM) copper physical layers.
Details
PME Aggregation function has the following characteristics:
Supports aggregation of up to 32 PMEs
Supports individual PMEs having different data rates (max 1:4 ratio)
Ensures low packet latency and preserves frame order
Scalable and resilient to PME failure
Independent of type of EFM copper PHY
Allows vendor discretionary algorithms for fragmentation
PAF Transmit function works by fragmenting incoming Ethernet frames into a number of fragments, limited in size to a range between 64 and 512 Bytes. A sequential fragmentation header is prepended to each fragment, indicating if the fragment is from the start-of-packet, end-of-packet or middle of packet. A frame check sequence (FCS) is appended to each fragment, which is then transmitted by the next available active PME in the aggregated group.
The following diagram illustrates the PAF fragmentation:
PAF Receive function reassembles the original frames from the received fragments, which are buffered in a per-MAC fragment buffer. The algorithm uses the fragmentation header to make sure that the reassembled frames are in order.
History
The PME Aggregation function was first defined in IEEE 802.3ah in 2004. The original Loop Aggregation proposal was submitted by Klaus Fosmark from now defunct First Mile |
https://en.wikipedia.org/wiki/Tolman%E2%80%93Oppenheimer%E2%80%93Volkoff%20equation | In astrophysics, the Tolman–Oppenheimer–Volkoff (TOV) equation constrains the structure of a spherically symmetric body of isotropic material which is in static gravitational equilibrium, as modelled by general relativity. The equation is
Here, is a radial coordinate, and and are the density and pressure, respectively, of the material at radius . The quantity , the total mass within , is discussed below.
The equation is derived by solving the Einstein equations for a general time-invariant, spherically symmetric metric. For a solution to the Tolman–Oppenheimer–Volkoff equation, this metric will take the form
where is determined by the constraint
When supplemented with an equation of state, , which relates density to pressure, the Tolman–Oppenheimer–Volkoff equation completely determines the structure of a spherically symmetric body of isotropic material in equilibrium. If terms of order are neglected, the Tolman–Oppenheimer–Volkoff equation becomes the Newtonian hydrostatic equation, used to find the equilibrium structure of a spherically symmetric body of isotropic material when general-relativistic corrections are not important.
If the equation is used to model a bounded sphere of material in a vacuum, the zero-pressure condition and the condition should be imposed at the boundary. The second boundary condition is imposed so that the metric at the boundary is continuous with the unique static spherically symmetric solution to the vacuum field equations, the Schwarzschild metric:
Total mass
is the total mass contained inside radius , as measured by the gravitational field felt by a distant observer. It satisfies .
Here, is the total mass of the object, again, as measured by the gravitational field felt by a distant observer. If the boundary is at , continuity of the metric and the definition of require that
Computing the mass by integrating the density of the object over its volume, on the other hand, will yield the larger value
The differenc |
https://en.wikipedia.org/wiki/Hyperbolization%20theorem | In geometry, Thurston's geometrization theorem or hyperbolization theorem implies that closed atoroidal Haken manifolds are hyperbolic, and in particular satisfy the Thurston conjecture.
Statement
One form of Thurston's geometrization theorem states:
If M is a compact irreducible atoroidal Haken manifold whose boundary has zero Euler characteristic, then the interior of M has a complete hyperbolic structure of finite volume.
The Mostow rigidity theorem implies that if a manifold of dimension at least 3 has a hyperbolic structure of finite volume, then it is essentially unique.
The conditions that the manifold M should be irreducible and atoroidal are necessary, as hyperbolic manifolds have these properties. However the condition that the manifold be Haken is unnecessarily strong. Thurston's hyperbolization conjecture states that a closed irreducible atoroidal 3-manifold with infinite fundamental group is hyperbolic, and this follows from Perelman's proof of the Thurston geometrization conjecture.
Manifolds with boundary
showed that if a compact 3 manifold is prime, homotopically atoroidal, and has non-empty boundary, then it has a complete hyperbolic structure unless it is homeomorphic to a certain manifold (T2×[0,1])/Z/2Z with boundary T2.
A hyperbolic structure on the interior of a compact orientable 3-manifold has finite volume if and only if all boundary components are tori, except for the manifold T2×[0,1] which has a hyperbolic structure but none of finite volume .
Proofs
Thurston never published a complete proof of his theorem for reasons that he explained in , though parts of his argument are contained in . and gave summaries of Thurston's proof. gave a proof in the case of manifolds that fiber over the circle, and and gave proofs for the generic case of manifolds that do not fiber over the circle. Thurston's geometrization theorem also follows from Perelman's proof using Ricci flow of the more general Thurston geometrization conjecture. |
https://en.wikipedia.org/wiki/Odd%20number%20theorem | The odd number theorem is a theorem in strong gravitational lensing which comes directly from differential topology.
The theorem states that the number of multiple images produced by a bounded transparent lens must be odd.
Formulation
The gravitational lensing is a thought to mapped from what's known as image plane to source plane following the formula :
.
Argument
If we use direction cosines describing the bent light rays, we can write a vector field on plane .
However, only in some specific directions , will the bent light rays reach the observer, i.e., the images only form where . Then we can directly apply the Poincaré–Hopf theorem .
The index of sources and sinks is +1, and that of saddle points is −1. So the Euler characteristic equals the difference between the number of positive indices and the number of negative indices . For the far field case, there is only one image, i.e., . So the total number of images is , i.e., odd. The strict proof needs Uhlenbeck's Morse theory of null geodesics. |
https://en.wikipedia.org/wiki/Davenport%20diagram | In acid base physiology, the Davenport diagram is a graphical tool, developed by Horace W. Davenport, that allows a clinician or investigator to describe blood bicarbonate concentrations and blood pH following a respiratory and/or metabolic acid-base disturbance. The diagram depicts a three-dimensional surface describing all possible states of chemical equilibria between gaseous carbon dioxide, aqueous bicarbonate and aqueous protons at the physiologically complex interface of the alveoli of the lungs and the alveolar capillaries. Although the surface represented in the diagram is experimentally determined, the Davenport diagram is rarely used in the clinical setting, but allows the investigator to envision the effects of physiological changes on blood acid-base chemistry. For clinical use there are two recent innovations: an Acid-Base Diagram which provides Text Descriptions for the abnormalities and a High Altitude Version that provides text descriptions appropriate for the altitude.
Derivation
When a sample of blood is exposed to air, either in the alveoli of the lung or in an in vitro laboratory experiment, carbon dioxide in the air rapidly enters into equilibrium with carbon dioxide derivatives and other species in the aqueous solution. Figure 1 illustrates the most important equilibrium reactions of carbon dioxide in blood relating to acid-base physiology:
Note that in this equation, the HB/B- buffer system represents all non-bicarbonate buffers present in the blood, such as hemoglobin in its various protonated and deprotonated states. Because many different non-bicarbonate buffers are present in human blood, the final equilibrium state reached at any given pCO2 is highly complex and cannot be readily predicted using theory alone. By depicting experimental results, the Davenport diagram provides a simple approach to describing the behavior of this complex system.
Figure 2 shows a Davenport diagram as commonly depicted in textbooks and the literature. To un |
https://en.wikipedia.org/wiki/Feasible%20region | In mathematical optimization and computer science, a feasible region, feasible set, or solution space is the set of all possible points (sets of values of the choice variables) of an optimization problem that satisfy the problem's constraints, potentially including inequalities, equalities, and integer constraints. This is the initial set of candidate solutions to the problem, before the set of candidates has been narrowed down.
For example, consider the problem of minimizing the function with respect to the variables and subject to and Here the feasible set is the set of pairs (x, y) in which the value of x is at least 1 and at most 10 and the value of y is at least 5 and at most 12. The feasible set of the problem is separate from the objective function, which states the criterion to be optimized and which in the above example is
In many problems, the feasible set reflects a constraint that one or more variables must be non-negative. In pure integer programming problems, the feasible set is the set of integers (or some subset thereof). In linear programming problems, the feasible set is a convex polytope: a region in multidimensional space whose boundaries are formed by hyperplanes and whose corners are vertices.
Constraint satisfaction is the process of finding a point in the feasible region.
Convex feasible set
A convex feasible set is one in which a line segment connecting any two feasible points goes through only other feasible points, and not through any points outside the feasible set. Convex feasible sets arise in many types of problems, including linear programming problems, and they are of particular interest because, if the problem has a convex objective function that is to be maximized, it will generally be easier to solve in the presence of a convex feasible set and any local optimum will also be a global optimum.
No feasible set
If the constraints of an optimization problem are mutually contradictory, there are no points that satisfy al |
https://en.wikipedia.org/wiki/Jackknife%20resampling | In statistics, the jackknife (jackknife cross-validation) is a cross-validation technique and, therefore, a form of resampling.
It is especially useful for bias and variance estimation. The jackknife pre-dates other common resampling methods such as the bootstrap. Given a sample of size , a jackknife estimator can be built by aggregating the parameter estimates from each subsample of size obtained by omitting one observation.
The jackknife technique was developed by Maurice Quenouille (1924–1973) from 1949 and refined in 1956. John Tukey expanded on the technique in 1958 and proposed the name "jackknife" because, like a physical jack-knife (a compact folding knife), it is a rough-and-ready tool that can improvise a solution for a variety of problems even though specific problems may be more efficiently solved with a purpose-designed tool.
The jackknife is a linear approximation of the bootstrap.
A simple example: mean estimation
The jackknife estimator of a parameter is found by systematically leaving out each observation from a dataset and calculating the parameter estimate over the remaining observations and then aggregating these calculations.
For example, if the parameter to be estimated is the population mean of random variable , then for a given set of i.i.d. observations the natural estimator is the sample mean:
where the last sum used another way to indicate that the index runs over the set .
Then we proceed as follows: For each we compute the mean of the jackknife subsample consisting of all but the -th data point, and this is called the -th jackknife replicate:
It could help to think that these jackknife replicates give us an approximation of the distribution of the sample mean and the larger the the better this approximation will be. Then finally to get the jackknife estimator we take the average of these jackknife replicates:
One may ask about the bias and the variance of . From the definition of as the average of the jackknife replic |
https://en.wikipedia.org/wiki/OOHDM | OOHDM (Object-Oriented Hypermedia Design Method) is a method for the development of Web applications.
It was one of the first methods to postulate the separation of concerns that defines its various models – requirements, conceptual, navigation, abstract interface and implementation. OOHDM, and its successor, SHDM (Semantic Hypermedia Design Method, which uses Semantic Web models) are supported by an open source, freely available environment, HyperDE.
See also
Web engineering
Web modeling
External links
OOHDM Wiki
HyperDE.
Software architecture
Web applications
Web development |
https://en.wikipedia.org/wiki/Inter-American%20Biodiversity%20Information%20Network | The Inter-American Biodiversity Information Network (IABIN) is a network dedicated to the adoption and promotion of ecoinformatics standards and protocols in all the countries of the Americas, thus facilitating the sound use of biological information for conservation and sustainable use of biodiversity. It is primarily an inter-governmental initiative but has a strong participation of a wide range of non-governmental partners.
The creation of IABIN in 1996 was mandated by the Heads of State at the Santa Cruz Summit of the Americas meeting in Bolivia. The Summit requested the Organization of American States (OAS) to act as the diplomatic host of the network.
Partnerships with similar or related initiatives is a critical part of the network’s strategy, so that existing standards or protocols can be promoted and not reinvented. For example, the Global Biodiversity Information Facility (GBIF) is leading the world in the development of specimen data standards, which IABIN is promoting. Strong relationships are also being developed with national environmental information organizations which are often very active and better placed to promote national programs, such as the National Biological Information Infrastructure (NBII) in the United States or the Instituto Nacional de Biodiversidad (INBio) of Costa Rica.
Governance
IABIN is a network in which the countries of the Americas as well as diverse governmental and civil society organizations participate. The highest governing body of the network is the IABIN Council, which meets about every year. Each participating country can send a representative, their “Focal Point”, to the Council, which defines the strategies and policies of the network. In practice, decisions are made by consensus and include a strong participation of non-governmental actors such as major non-governmental organizations (NGOs).
At present, 34 countries have designated IABIN Focal Points. Most countries have designated their Clearing House Mechanis |
https://en.wikipedia.org/wiki/Glycolipid%20transfer%20protein | Glycolipid transfer protein is a cytosolic protein that catalyses the transfer of glycolipids between different intracellular membranes.
It was discovered by Raymond J. Metz and Norman S. Radin in 1980 and partially purified and characterized in 1982.
Recent reviews on structure and possible function are available.
This protein transports primarily different glycosphingolipids and glyceroglycolipids between intracellular membranes, but not phospholipids. It might be also involved in translocation of glucosylceramides. It was found in brain, kidney, spleen, lung, cerebellum, liver and heart.
Human proteins containing this domain
GLTP; PLEKHA8; PLEKHA9; |
https://en.wikipedia.org/wiki/Archer%27s%20paradox | The archer's paradox is the phenomenon of an arrow traveling in the direction it is pointed at full draw, when it seems that the arrow would have to pass through the starting position it was in before being drawn, where it was pointed to the side of the target.
The bending of the arrow when released is the explanation for why the paradox occurs and should not be confused with the paradox itself.
Flexing of the arrow when shot from a modern 'centre shot' bow is still present and is caused by a variety of factors, mainly the way the string is deflected from the fingers as the arrow is released.
The term was first used by E. J. Rendtroff in 1913, but detailed descriptions of the phenomenon appear in archery literature as early as Horace A. Ford's 1859 text "Archery: Its Theory and Practice". As understanding was gained about the arrow flexing around and out of the way of the bow as it is shot (as first filmed by Clarence Hickman) and then experiencing oscillating back-and-forth bending as it travels toward the target, this dynamic flexing has incorrectly become a common usage of the term. This misuse sometimes causes misunderstanding on the part of those only familiar with modern target bows, which often have risers with an eccentrically cutout "arrow window"; being "centre shot", these bows do not exhibit any paradoxical behaviour as the arrow is always pointing visually along its line of flight.
Details
In order to be accurate, an arrow must have the correct stiffness, or "dynamic spine", to flex out of the way of the bow and to return to the correct path as it leaves the bow. Incorrect dynamic spine results in unpredictable contact between the arrow and the bow, therefore unpredictable forces on the arrow as it leaves the bow, and therefore reduced accuracy. Additionally, if an archer shoots several arrows with different dynamic spines, as they clear the bow they will be deflected on launch by different amounts and so will strike in different places. Competiti |
https://en.wikipedia.org/wiki/Australian%20Centre%20for%20Disease%20Preparedness | The Australian Centre for Disease Preparedness (ACDP), formerly known as the Australian Animal Health Laboratory (AAHL), in Geelong, Victoria, Australia is a high security laboratory, run by the CSIRO for exotic animal disease diagnosis and research. The lab is one of four Biosafety Level-4 labs in the country.
It opened in 1985 costing $185 million, built on Corio Oval.
In November 2012 it delivered an experimental vaccine to help protect horses against the deadly Hendra virus.
History
In 1977, Jim Peacock of the Australian Academy of Science asked Bill Snowdon, then Chief CSIRO AAHL if he could have the newly released USA NIH and the British equivalent requirements for the development of infrastructure for bio-containment reviewed by AAHL personnel with a view to recommending the adoption of one of them by Australian authorities. The review was carried out by CSIRO AAHL Project Manager Bill Curnow and CSIRO Engineer Arthur Jenkins. They drafted outcomes for each of the levels of security. AAHL was notionally classified as "substantially beyond P4". These were adopted by the Australian Academy of Science and became the basis for Australian Legislation.
The Australian Centre for Disease Preparedness was commissioned in 1985 as the Australian Animal Health Laboratory, includes a number of laboratories and animal house facilities capable of operating at three steps of negative pressure below the lowest pressure within any part of the extramural wind-zone of the building exterior. External pressure and the cascaded negative pressure zones are measured and maintained in real time by electronic sensors, electronically controlled supply and exhaust air handling systems and purpose developed predictive logic controllers in support of management protocols to manage air locks, access and services to prevent loss or ingress of potentially contaminated gases, solids or liquids . Supply air is protected by two 0.001 HEPA filters in tandem, (series mounted) with appropriat |
https://en.wikipedia.org/wiki/Lung%20compliance | Lung compliance, or pulmonary compliance, is a measure of the lung's ability to stretch and expand (distensibility of elastic tissue). In clinical practice it is separated into two different measurements, static compliance and dynamic compliance. Static lung compliance is the change in volume for any given applied pressure. Dynamic lung compliance is the compliance of the lung at any given time during actual movement of air.
Low compliance indicates a stiff lung (one with high elastic recoil) and can be thought of as a thick balloon – this is the case often seen in fibrosis. High compliance indicates a pliable lung (one with low elastic recoil) and can be thought of as a grocery bag – this is the case often seen in emphysema. Compliance is highest at moderate lung volumes, and much lower at volumes which are very low or very high. The compliance of the lungs demonstrate lung hysteresis; that is, the compliance is different on inspiration and expiration for identical volume.
Calculation
Pulmonary compliance is calculated using the following equation, where ΔV is the change in volume, and ΔP is the change in pleural pressure:
For example, if a patient inhales 500 mL of air from a spirometer with an intrapleural pressure before inspiration of −5 cm H2O and −10 cm H2O at the end of inspiration. Then:
Static compliance (Cstat)
Static compliance represents pulmonary compliance during periods without gas flow, such as during an inspiratory pause. It can be calculated with the formula:
where
VT = tidal volume;
Pplat = plateau pressure;
PEEP = positive end-expiratory pressure.
Pplat is measured at the end of inhalation and prior to exhalation by using an inspiratory hold maneuver. During this maneuver, airflow is transiently (~0.5 sec) discontinued, which eliminates the effects of airway resistance. Pplat is never bigger than PIP and is typically <10 cm H2O lower than PIP when airway resistance is not elevated.
Dynamic compliance (Cdyn)
Dynamic compliance represe |
https://en.wikipedia.org/wiki/Mike%20Lesser | Michael John Lesser (28 September 1943 – 1 July 2015) was a mathematical philosopher and political activist.
Early life
The youngest member of the Committee of 100, he was sent, aged 16, to Wormwood Scrubs Prison along with most of the committee. He served two spells as contributor to London's underground journal International Times.
He was active in May 1968 in France.
Career
In 1992 he was the co-author, with Prof A. Wuensche, of the book The Global Dynamics Of Cellular Automata, published in the Santa Fe Institute's Reference Volumes. The book is an atlas of emergent forms evolving from the apparently chaotic product of a set of iterated logical operations.
He was assistant to the Directing Professor, P. Allen, at the Institute for Ecotechnological Research at Cranfield University. He is the co-author of several scientific papers on dynamical systems theory with Allen.
He worked on super computers at NASA's Goddard Jet Propulsion Lab and at the Rutherford Appleton Laboratories in Oxon, UK.
He published papers on autism with Dinah Murray, with whom he co-founded Autism and Computing, a non-profit organization.
In 2009 he founded The International Times Archive, a free archive of every page of International Times from its first issue in 1966 to its last in 1994.
A biographical interview may also be found in the style magazine Dazed & Confused. A more complete autobiography may be found in The Times.
Death
Lesser died in London in 2015 at the age of 71. In December 2015, coroner Andrew Walker at Barnet Coroners Court ruled that Lesser died from asphyxiation. Evidence was given that Lesser had suffered from depression for "many years". He had a heart bypass in 1999 and in June 2015 had been told that he had terminal lung cancer. He left a note for his wife and friends. |
https://en.wikipedia.org/wiki/Robert%20Methuen%2C%207th%20Baron%20Methuen | Robert Alexander Holt Methuen, 7th Baron Methuen (22 July 1931 – 9 July 2014), was a British Liberal Democrat peer. He was one of the ninety hereditary peers elected to remain in the House of Lords after the House of Lords Act 1999.
Biography
Methuen was the third and youngest son of Anthony Methuen, 5th Baron Methuen, by his wife Grace Durning Holt, daughter of Sir Richard Durning Holt, Bt. He was educated at Shrewsbury School before going up to Trinity College, Cambridge, where he graduated in 1957 with a Bachelor of Arts (BA) degree in Engineering.
Methuen worked as a design engineer for Westinghouse Brake and Signal Company from 1957 to 1967, and then as a computer systems engineer for IBM UK Ltd from 1968 to 1975 and for Rolls-Royce Holdings plc from 1975 to 1994. In 1994, he succeeded his elder brother to the title. In the House of Lords, he served on the Science and Technology Select Committee and other committees. He also voted to block the Marriage (Same Sex Couples) Act 2013.
Lord Methuen married firstly Mary Catherine Jane Hooper in 1958; they divorced in 1993. He married secondly Margrit Andrea Hadwiger one year later. He has two daughters by his first wife: Charlotte Mary Methuen (born 1964) and Henrietta Christian Methuen-Jones (born 1965) who later changed her name to Kittie. Kittie was married to Robert Jones (who took the surname Methuen-Jones) and has three children: Teresa Methuen-Jones (born 1990), Keziah Methuen-Jones (born 1992) and Miriam Methuen-Jones (born 1997).
He died after a short illness on 9 July 2014. He was succeeded in the title by his first cousin once removed, James Methuen-Campbell (born 1952).
Ancestry
Arms
See also
Baron Methuen |
https://en.wikipedia.org/wiki/Multitaper | In signal processing, multitaper is a spectral density estimation technique developed by David J. Thomson. It can estimate the power spectrum SX of a stationary ergodic finite-variance random process X, given a finite contiguous realization of X as data.
Motivation
The multitaper method overcomes some of the limitations of non-parametric Fourier analysis. When applying the Fourier transform to extract spectral information from a signal, we assume that each Fourier coefficient is a reliable representation of the amplitude and relative phase of the corresponding component frequency. This assumption, however, is not generally valid for empirical data. For instance, a single trial represents only one noisy realization of the underlying process of interest. A comparable situation arises in statistics when estimating measures of central tendency i.e., it is bad practice to estimate qualities of a population using individuals or very small samples. Likewise, a single sample of a process does not necessarily provide a reliable estimate of its spectral properties. Moreover, the naive power spectral density obtained from the signal's raw Fourier transform is a biased estimate of the true spectral content.
These problems are often overcome by averaging over many realizations of the same event after applying a taper to each trial. However, this method is unreliable with small data sets and undesirable when one does not wish to attenuate signal components that vary across trials. Furthermore, even when many trials are available the untapered periodogram is generally biased (with the exception of white noise) and the bias depends upon the length of each realization, not the number of realizations recorded. Applying a single taper reduces bias but at the cost of increased estimator variance due to attenuation of activity at the start and end of each recorded segment of the signal. The multitaper method partially obviates these problems by obtaining multiple independent e |
https://en.wikipedia.org/wiki/Peak%20power | Peak power may refer to:
the maximum power rating of electronic device
Audio peak power, power handling in audio equipment
Watt-peak in electrical generation systems
Peaking power plant of electric utilities |
https://en.wikipedia.org/wiki/Watterson%20estimator | In population genetics, the Watterson estimator is a method for describing the genetic diversity in a population. It was developed by Margaret Wu and G. A. Watterson in the 1970s. It is estimated by counting the number of polymorphic sites. It is a measure of the "population mutation rate" (the product of the effective population size and the neutral mutation rate) from the observed nucleotide diversity of a population. , where is the effective population size and is the per-generation mutation rate of the population of interest ( ). The assumptions made are that there is a sample of haploid individuals from the population of interest, that there are infinitely many sites capable of varying (so that mutations never overlay or reverse one another), and that .
Because the number of segregating sites counted will increase with the number of sequences looked at, the correction factor is used.
The estimate of , often denoted as , is
where is the number of segregating sites (an example of a segregating site would be a single-nucleotide polymorphism) in the sample and
is the th harmonic number.
This estimate is based on coalescent theory. Watterson's estimator is commonly used for its simplicity. When its assumptions are met, the estimator is unbiased and the variance of the estimator decreases with increasing sample size or recombination rate. However, the estimator can be biased by population structure. For example, is downwardly biased in an exponentially growing population. It can also be biased by violation of the infinite-sites mutational model; if multiple mutations can overwrite one another, Watterson's estimator will be biased downward.
Comparing the value of the Watterson's estimator, to nucleotide diversity is the basis of Tajima's D which allows inference of the evolutionary regime of a given locus.
See also
Tajima's D
Coupon collector's problem
Ewens sampling formula |
https://en.wikipedia.org/wiki/Jacques%20Dixmier | Jacques Dixmier (born 24 May 1924) is a French mathematician. He worked on operator algebras, especially C*-algebras, and wrote several of the standard reference books on them, and introduced the Dixmier trace and the Dixmier mapping.
Biography
Dixmier received his Ph.D. in 1949 from the University of Paris, and his students include Alain Connes.
In 1949 upon the initiative of Jean-Pierre Serre and Pierre Samuel, Dixmier became a member of Bourbaki, in which he made essential contributions to the Bourbaki volume on Lie algebras. After retiring as professor emeritus from the University of Paris VI, he spent five years at the Institut des Hautes Études Scientifiques.
Often, there is made the erroneous claim that Dixmier originated the name von Neumann algebra for the operator algebras introduced by John von Neumann, but Dixmier said in an interview that the name originated from a proposal by Jean Dieudonné.
Dixmier was an invited speaker at the International Congress of Mathematicians in 1966 in Moscow with the talk Espace dual d'une algèbre, ou d'un groupe localement compact and again in 1978 in Helsinki with the talk Algèbres enveloppantes.
Publications
J. Dixmier, C*-algebras. Translated from the French by Francis Jellett. North-Holland Mathematical Library, Vol. 15. North-Holland Publishing Co., Amsterdam-New York-Oxford, 1977. xiii+492 pp.
A translation of Les C*-algèbres et leurs représentations, Gauthier-Villars, 1969.
A translation of Algèbres enveloppantes, Cahiers Scientifiques, Fasc. XXXVII. Gauthier-Villars Éditeur, Paris-Brussels-Montreal, Que., 1974. ii+349 pp.
J. Dixmier, von Neumann algebras, Translated from the second French edition by F. Jellett. North-Holland Mathematical Library, 27. North-Holland Publishing Co., Amsterdam-New York, 1981. xxxviii+437 pp.
A translation of Les algèbres d'opérateurs dans l'espace hilbertien: algèbres de von Neumann, Gauthier-Villars (1957), the first book about von Neumann algebras.
Books
Notes
1924 |
https://en.wikipedia.org/wiki/Binocular%20disparity | Binocular disparity refers to the difference in image location of an object seen by the left and right eyes, resulting from the eyes’ horizontal separation (parallax). The brain uses binocular disparity to extract depth information from the two-dimensional retinal images in stereopsis. In computer vision, binocular disparity refers to the difference in coordinates of similar features within two stereo images.
A similar disparity can be used in rangefinding by a coincidence rangefinder to determine distance and/or altitude to a target. In astronomy, the disparity between different locations on the Earth can be used to determine various celestial parallax, and Earth's orbit can be used for stellar parallax.
Definition
Human eyes are horizontally separated by about 50–75 mm (interpupillary distance) depending on each individual. Thus, each eye has a slightly different view of the world around. This can be easily seen when alternately closing one eye while looking at a vertical edge. The binocular disparity can be observed from apparent horizontal shift of the vertical edge between both views.
At any given moment, the line of sight of the two eyes meet at a point in space. This point in space projects to the same location (i.e. the center) on the retinae of the two eyes. Because of the different viewpoints observed by the left and right eye however, many other points in space do not fall on corresponding retinal locations. Visual binocular disparity is defined as the difference between the point of projection in the two eyes and is usually expressed in degrees as the visual angle.
The term "binocular disparity" refers to geometric measurements made external to the eye. The disparity of the images on the actual retina depends on factors internal to the eye, especially the location of the nodal points, even if the cross section of the retina is a perfect circle. Disparity on retina conforms to binocular disparity when measured as degrees, while much different if m |
https://en.wikipedia.org/wiki/Solar-like%20oscillations | Solar-like oscillations are oscillations in stars that are excited in the same way as those in the Sun, namely by turbulent convection in its outer layers. Stars that show solar-like oscillations are called solar-like oscillators. The oscillations are standing pressure and mixed pressure-gravity modes that are excited over a range in frequency, with the amplitudes roughly following a bell-shaped distribution. Unlike opacity-driven oscillators, all the modes in the frequency range are excited, making the oscillations relatively easy to identify. The surface convection also damps the modes, and each is well-approximated in frequency space by a Lorentzian curve, the width of which corresponds to the lifetime of the mode: the faster it decays, the broader is the Lorentzian. All stars with surface convection zones are expected to show solar-like oscillations, including cool main-sequence stars (up to surface temperatures of about 7000K), subgiants and red giants. Because of the small amplitudes of the oscillations, their study has advanced tremendously thanks to space-based missions (mainly COROT and Kepler).
Solar-like oscillations have been used, among other things, to precisely determine the masses and radii of planet-hosting stars and thus improve the measurements of the planets' masses and radii.
Red giants
In red giants, mixed modes are observed, which are in part directly sensitive to the core properties of the star. These have been used to distinguish red giants burning helium in their cores from those that are still only burning hydrogen in a shell, to show that the cores of red giants are rotating more slowly than models predict and to constrain the internal magnetic fields of the cores
Echelle diagrams
The peak of the oscillation power roughly corresponds to lower frequencies and radial orders for larger stars. For the Sun, the highest amplitude modes occur around a frequency of 3 mHz with order , and no mixed modes are observed. For more massive and |
https://en.wikipedia.org/wiki/Tzanck%20test | In dermatopathology, the Tzanck test, also Tzanck smear, is scraping of an ulcer base to look for Tzanck cells. It is sometimes also called the chickenpox skin test and the herpes skin test. It is a simple, low-cost, and rapid office based test.
Tzanck cells (acantholytic cells) are found in:
Herpes simplex
Varicella and herpes zoster
Pemphigus vulgaris
Cytomegalovirus
Arnault Tzanck did the first cytological examinations in order to diagnose skin diseases. To diagnose pemphigus, he identified acantholytic cells, and to diagnose of herpetic infections he identified multinucleated giant cells and acantholytic cells. He extended his cytologic findings to certain skin tumors as well.
Even though cytological examination can provide rapid and reliable diagnosis for many skin diseases, its use is limited to a few diseases. In endemic regions, Tzanck test is used to diagnose leishmaniasis and leprosy. For other regions, Tzanck test is mainly used to diagnose pemphigus and herpetic infections. Some clinics use biopsies even for herpetic infections. This is because the advantages of this test are not well known, and the main textbooks of dermatopathology do not include dedicated sections for cytology or Tzanck smear. A deep learning model called TzanckNet has been developed to lower the experience barrier needed to use this test.
Procedure
Unroof vesicle and scrape base w/ sterile №15 scalpel blade
Smear with cotton stick onto a clean glass slide
Fix w/ gentle heat or air dry
Fix w/ MeOH (Methanol)
Stain w/ Giemsa, methylene blue or Wright’s stain.
Microscopic examination using an oil immersion lens. (Look for multinucleated giant cells)
A modified test can be performed using proprietary agents which requires fewer steps and allows the sample to be fixed quicker.
Cytologic findings
For microscopic evaluation, samples are first scanned with low magnification objectives (X4 and X10) and then examined in detail with the high magnification objective (X100). The X4 |
https://en.wikipedia.org/wiki/Alipay | Alipay () is a third-party mobile and online payment platform, established in Hangzhou, China in February 2004 by Alibaba Group and its founder Jack Ma. In 2015, Alipay moved its headquarters to Pudong, Shanghai, although its parent company Ant Financial remains Hangzhou-based.
Alipay overtook PayPal as the world's largest mobile (digital) payment platform in 2013. As of June 2020, Alipay serves over 1.3 billion users and 80 million merchants. According to the statistics of the fourth quarter of 2018, Alipay has a 55.32% share of the third-party payment market in mainland China, and it continues to grow.
Along with WeChat, Alipay has been described to be China’s super-app with a wide range of functionalities including ridesharing, travel booking and medical appointments.
History
The service was first launched in 2003, by Taobao. The People's Bank of China, China's central bank, issued licensing regulations in June 2010 for third-party payment providers. It also issued separate guidelines for foreign-funded payment institutions. Because of this, Alipay, which accounted for half of China's non-bank online payment market, was restructured as a domestic company controlled by Alibaba CEO Jack Ma in order to facilitate the regulatory approval for the license.
The 2010 transfer of Alipay's ownership was controversial, with media reports in 2011 that Yahoo! and Softbank (Alibaba Group's controlling shareholders) were not informed of the sale for nominal value. Chinese business publications Century Weekly criticised Ma, who stated that Alibaba Group's board of directors was aware of the transaction. The incident was criticised in foreign and Chinese media as harming foreign trust in making Chinese investments. The ownership dispute was resolved by Alibaba Group, Yahoo!, and Softbank in July 2011.
In 2013 Alipay launched a financial product platform called Yu'E Bao (余额宝). Alipay partnered with Tianhong Asset Management to launch the it. Alibaba (the parent company of A |
https://en.wikipedia.org/wiki/Near-field%20electromagnetic%20ranging | Near-field electromagnetic ranging (NFER) refers to any radio technology employing the near-field properties of radio waves as a Real Time Location System (RTLS).
Overview
Near-field electromagnetic ranging is an emerging RTLS technology that employs transmitter tags and one or more receiving units. Operating within a half-wavelength of a receiver, transmitter tags must use relatively low frequencies (less than 30 MHz) to achieve significant ranging. Depending on the choice of frequency, NFER has the potential for range resolution of and ranges up to .
Technical Discussion
The phase relations between the EH components of an electro-magnetic field ((E and H are the components E=electric and H=magnetic)) vary with distance around small antennas. This was first discovered by Heinrich Hertz and is formulated with Maxwell's field theory.
Close to a small antenna, the electric and magnetic field components of a radio wave are 90 degrees out of phase. As the distance from the antenna increases, the EH phase difference decreases. Far from a small antenna in the far-field, the EH phase difference goes to zero. Thus a receiver that can separately measure the electric and magnetic field components of a near-field signal and compare their phases can measure the range to the transmitter.
Advantages
NFER technology is a different approach for locating systems. It has several inherent advantages over other RTLS systems.
First, no signal modulation is required, so baseband signals with an arbitrarily small bandwidth may be used for ranging.
Second, precise synchronization is not required between different receivers: in fact, a local range measurement can be made with just a single receiver.
Third, since EH phase differences are preserved when a signal is down-converted to baseband, high range precision may be achieved with relatively low time precision.
For instance, a radio wave at 1 MHz has a period of 1 µs, and the EH phase difference changes about 45 degrees betw |
https://en.wikipedia.org/wiki/Information%20exchange | Information exchange or information sharing means that people or other entities pass information from one to another. This could be done electronically or through certain systems. These are terms that can either refer to bidirectional information transfer in telecommunications and computer science or communication seen from a system-theoretic or information-theoretic point of view. As "information" in this context invariably refers to (electronic) data that encodes and represents the information at hand, a broader treatment can be found under data exchange.
Information exchange has a long history in information technology. Traditional information sharing referred to one-to-one exchanges of data between a sender and receiver. Online information sharing gives useful data to businesses for future strategies based on online sharing. These information exchanges are implemented via dozens of open and proprietary protocols, message, and file formats. Electronic data interchange (EDI) is a successful implementation of commercial data exchanges that began in the late 1970s and remains in use today.
Some controversy comes when discussing regulations regarding information exchange. Initiatives to standardize information sharing protocols include extensible markup language (XML), simple object access protocol (SOAP), and web services description language (WSDL).
From the point of view of a computer scientist, the four primary information sharing design patterns are sharing information one-to-one, one-to-many, many-to-many, and many-to-one. Technologies to meet all four of these design patterns are evolving and include blogs, wikis, really simple syndication, tagging, and chat.
One example of United States government's attempt to implement one of these design patterns (one to one) is the National Information Exchange Model (NIEM). One-to-one exchange models fall short of supporting all of the required design patterns needed to fully implement data exploitation technology.
A |
https://en.wikipedia.org/wiki/Connection-oriented%20Ethernet | Connection-oriented Ethernet refers to the transformation of Ethernet, a connectionless communication system by design, into a connection-oriented system. The aim of connection-oriented Ethernet is to create a networking technology that combines the flexibility and cost-efficiency of Ethernet with the reliability of connection-oriented protocols. Connection-oriented Ethernet is used in commercial carrier grade networks.
Traditional carrier networks deliver services at very high availability. Packet-switched networks are different, as they offer services based on statistical multiplexing. Moreover, packet transport equipment, which makes up the machinery of data networking, leaves most of the carrier-grade qualities such as quality of service, routing, provisioning, and security, to be realized by packet processing. Addressing these needs in a cost-efficient way is a challenge for packet-based technologies.
The IP-MPLS approach aims at providing guaranteed services over the Internet Protocol using a multitude of networking protocols to create, maintain and handle packet data streams. While this approach solves the problem, it inevitably also creates a great deal of complexity.
This has resulted in the emergence of connection-oriented Ethernet which includes a variety of methodologies to utilize Ethernet for the same functionalities otherwise based on extensive IP protocols. The challenge of carrier Ethernet is to add carrier-grade functionality to Ethernet equipment without losing the cost-effectiveness and simplicity that makes it attractive in the first place. To meet this challenge, common connection-oriented Ethernet solutions have chosen to rid themselves of the complex parts of packet transport to achieve stability and control. Key connection-oriented Ethernet technologies used to achieve this include mainly IEEE 802.1ah, Provider Backbone Transport and MPLS-TP, and formerly T-MPLS.
PBT and PBB
Provider Backbone Transport (PBT) is connection-oriented |
https://en.wikipedia.org/wiki/Windows%20Rally | Windows Rally is a set of technologies from Microsoft intended to simplify the setup and maintenance of wired and wireless network-connected devices. They aim to increase reliability and security of connectivity for users who connect the devices to the Internet or to computers running Microsoft Windows. These technologies provide control of network quality of service (QoS) and diagnostics for data sharing, communications, and entertainment. Windows Rally technologies provide provisioning for the following devices:
Wireless access points, PCs, and servers
Network printers, projectors, printer bridges, digital still cameras, and game consoles
Digital media receivers, network media players, set-top boxes, digital photo frames, and PDAs
Windows Rally technologies
Windows Rally includes the following set of technologies:
LLTD
The Link Layer Topology Discovery (LLTD) protocol enables applications to discover devices and determine network topology. In Windows Vista, it enables a graphical view of all the devices in the network on the Network Map. For Windows XP computers to appear on the Network Map, the LLTD Responder must be downloaded and installed. Devices that provide audio or video playback or that are bandwidth sensitive can implement the QoS Extension part of the protocol so that they receive prioritized streams and that changes in available bandwidth have less impact on the playback experience.
qWAVE
Windows Vista includes qWAVE, a pre-configured quality of service API for time-dependent multimedia data, such as audio or video streams. qWAVE uses different packet priority schemes for real-time flows (such as multimedia packets) and best-effort flows (such as file downloads or e-mails) to ensure that real-time data gets delayed as little as possible, while providing a high-quality channel for other data packets. qWAVE-enabled applications together with devices that implement the LLTD QoS Extensions aim to improve an end user's experience of streaming vide |
https://en.wikipedia.org/wiki/Quinone-interacting%20membrane-bound%20oxidoreductase | Quinone-interacting membrane-bound oxidoreductase is a membrane-bound protein complex present in the electron transport chain of sulfate reducers (e.g. Desulfovibrio species) and some sulfur oxidizers.
It was first described by Pires et al. (2003). |
https://en.wikipedia.org/wiki/Phylogenetic%20nomenclature | Phylogenetic nomenclature is a method of nomenclature for taxa in biology that uses phylogenetic definitions for taxon names as explained below. This contrasts with the traditional approach, in which taxon names are defined by a type, which can be a specimen or a taxon of lower rank, and a description in words. Phylogenetic nomenclature is currently regulated by the International Code of Phylogenetic Nomenclature (PhyloCode).
Definitions
Phylogenetic nomenclature ties names to clades, groups consisting of an ancestor and all its descendants. These groups can equivalently be called monophyletic. There are slightly different ways of specifying the ancestor, which are discussed below. Once the ancestor is specified, the meaning of the name is fixed: the ancestor and all organisms which are its descendants are included in the named taxon. Listing all these organisms (i.e. providing a full circumscription) requires the full phylogenetic tree to be known. In practice, there are only one or more hypotheses as to the correct tree. Different hypotheses lead to different organisms being thought to be included in the named taxon, but do not affect what organisms the name actually applies to. In this sense the name is independent of theory revision.
Phylogenetic definitions of clade names
Phylogenetic nomenclature ties names to clades, groups consisting solely of an ancestor and all its descendants. All that is needed to specify a clade, therefore, is to designate the ancestor. There are a number of ways of doing this. Commonly, the ancestor is indicated by its relation to two or more specifiers (species, specimens, or traits) that are mentioned explicitly. The diagram shows three common ways of doing this. For previously defined clades A, B, and C, the clade X can be defined as:
A node-based definition could read: "the last common ancestor of A and B, and all descendants of that ancestor". Thus, the entire line below the junction of A and B does not belong to the clade to |
https://en.wikipedia.org/wiki/Direct%20Graphics%20Access | Direct Graphics Access is a plug-in for the X display servers that allows client programs direct access to the frame buffer.
Graphics hardware communicates via a chunk of memory called a frame buffer. This is an array of values that represent pixel color values on the screen. Writing the appropriate values into the frame buffer therefore allows a program to paint areas of the screen.
However, as with any shared resource, problems occur when multiple programs attempt to access the same resource, as they tend to write over each other's work. In the X Window System, this is solved by having a central display server that mediates between programs that want to draw on the screen. The display server also used to perform a lot of the drawing work, allowing programs to say Draw me a circle of this radius filled with this pattern or draw this text in this font. The X server does all this work, freeing programmers from having to write their own drawing code. Another advantage of the X architecture is that it works over a network, allowing programs on one machine to display output on the screen of another.
Direct Graphics Access allows direct access to the frame buffer and the X-server hands over control of the frame buffer to the client program and waits for the client to hand it back. This means that the client program has control of the whole screen, and so it is mostly used for full-screen video/games.
See also
GLX – OpenGL over the X protocol
Direct Rendering Infrastructure
External links
XFree86 server 4.x Design (DRAFT) : DGA Extension
XDGA man page
Image processing
X Window extensions |
https://en.wikipedia.org/wiki/Prodromus%20Systematis%20Naturalis%20Regni%20Vegetabilis | Prodromus Systematis Naturalis Regni Vegetabilis (1824–1873), also known by its standard botanical abbreviation Prodr. (DC.), is a 17-volume treatise on botany initiated by Augustin Pyramus de Candolle. De Candolle intended it as a summary of all known seed plants, encompassing taxonomy, ecology, evolution and biogeography. He authored seven volumes between 1824 and 1839, but died in 1841. His son, Alphonse de Candolle, then took up the work, editing a further ten volumes, with contributions from a range of authors. Volume 17 was published in October 1873. The fourth and final part of the index came out in 1874. The Prodromus remained incomplete, dealing only with dicotyledons.
In the Prodromus, De Candolle further developed his concept of families. Note that this system was published well before there were internationally accepted rules for botanical nomenclature. Here, a family is indicated as "ordo". Terminations for families were not what they are now. Neither of these phenomena is a problem from a nomenclatural perspective, the present day ICN provides for this. Within the dicotyledons ("classis prima DICOTYLEDONEÆ") the De Candolle system recognises (Pagination from Prodromus, 17 Parts) the list:
System
Subclassis I. THALAMIFLORÆ [Part I]
ordo I. RANUNCULACEÆ (Page 1)
ordo II. DILLENIACEÆ (Page 67)
ordo III. MAGNOLIACEÆ (Page 77)
ordo IV. ANONACEÆ [sic] (Page 83)
ordo V. MENISPERMACEÆ (Page 95)
ordo VI. BERBERIDEÆ
ordo VII. PODOPHYLLACEÆ
ordo VIII. NYMPHÆACEÆ
ordo VIIIbis. SARRACENIACEÆ
ordo IX. PAPAVERACEÆ
ordo X. FUMARIACEÆ (Page 125)
ordo XIbis. RESEDACEÆ
ordo XI. CRUCIFERÆ
ordo XII. CAPPARIDEÆ
ordo XIII. FLACOURTIANEÆ
ordo XIV. BIXINEÆ
ordo XIVbis. LACISTEMACEÆ
ordo XV. CISTINEÆ
ordo XVI. VIOLARIEÆ
ordo XVII. DROSERACEÆ
ordo XVIII. POLYGALACEÆ
ordo XIX. TREMANDREÆ
ordo XX. PITTOSPOREÆ
ordo XXI. FRANKENIACEÆ
ordo XXII. CARYOPHYLLEÆ
ordo XXIII. LINEÆ
ordo XXIV. MALVACEÆ
ordo XXV. BOMBACEÆ [sic]
ordo XXVI. BYTTNERIACEÆ
ordo X |
https://en.wikipedia.org/wiki/ANT%20%28network%29 | ANT is a proprietary (but open access) multicast wireless sensor network technology designed and marketed by ANT Wireless (a division of Garmin Canada). It provides personal area networks (PANs), primarily for activity trackers. ANT was introduced by Dynastream Innovations in 2003, followed by the low-power standard ANT+ in 2004, before Dynastream was bought by Garmin in 2006.
ANT defines a wireless communications protocol stack that enables hardware operating in the 2.4 GHz ISM band to communicate by establishing standard rules for co-existence, data representation, signalling, authentication, and error detection. It is conceptually similar to Bluetooth low energy, but is oriented towards use with sensors.
the ANT website lists almost 200 brands using ANT technology. Samsung and, to a lesser part, Fujitsu, HTC, Kyocera, Nokia and Sharp added native support (without the use of a USB adapter) to their smartphones, with Samsung starting support with the Galaxy S4 and ending support with the Galaxy S20 line.
Overview
ANT-powered nodes are capable of acting as sources or sinks within a wireless sensor network concurrently. This means the nodes can act as transmitters, receivers, or transceivers to route traffic to other nodes. In addition, every node is capable of determining when to transmit based on the activity of its neighbors.
Technical information
ANT can be configured to spend long periods in a low-power sleep mode (consuming of the order of microamps of current), wake up briefly to communicate (when consumption rises to a peak of 22mA (at -5dB) during reception and 13.5mA (at -5 dB) during transmission) and return to sleep mode. Average current consumption for low message rates is less than 60 microamps on some devices.
Each ANT channel consists of one or more transmitting nodes and one or more receiving nodes, depending on the network topology. Any node can transmit or receive, so the channels are bi-directional.
ANT accommodates three types of messagin |
https://en.wikipedia.org/wiki/Soft%20laser%20desorption | Soft laser desorption (SLD) is laser desorption of large molecules that results in ionization without fragmentation. "Soft" in the context of ion formation means forming ions without breaking chemical bonds. "Hard" ionization is the formation of ions with the breaking of bonds and the formation of fragment ions.
Background
The term "soft laser desorption" has not been widely used by the mass spectrometry community, which in most cases uses matrix-assisted laser desorption/ionization (MALDI) to indicate soft laser desorption ionization that is aided by a separate matrix compound. The term soft laser desorption was used most notably by the Nobel Foundation in public information released in conjunction with the 2002 Nobel Prize in Chemistry. Koichi Tanaka was awarded 1/4 of the prize for his use of a mixture of cobalt nanoparticles and glycerol in what he called the “ultra fine metal plus liquid matrix method” of laser desorption ionization. With this approach, he was able to demonstrate the soft ionization of proteins. The MALDI technique was demonstrated (and the name coined) in 1985 by Michael Karas, Doris Bachmann, and Franz Hillenkamp, but ionization of proteins by MALDI was not reported until 1988, immediately after Tanaka's results were reported.
Some have argued that Karas and Hillenkamp were more deserving of the Nobel Prize than Tanaka because their crystalline matrix method is much more widely used than Tanaka's liquid matrix. Countering this argument is the fact that Tanaka was the first to use a 337 nm nitrogen laser while Karas and Hillenkamp were using a 266 nm Nd:YAG laser. The "modern" MALDI approach came into being several years after the first soft laser desorption of proteins was demonstrated.
The term soft laser desorption is now used to refer to MALDI as well as "matrix free" methods for laser desorption ionization with minimal fragmentation.
Variants
Graphite
The surface-assisted laser desorption/ionization (SALDI) approach uses a liquid plu |
https://en.wikipedia.org/wiki/Transpulmonary%20pressure | Transpulmonary pressure is the difference between the alveolar pressure and the intrapleural pressure in the pleural cavity. During human ventilation, air flows because of pressure gradients.
Ptp = Palv – Pip. Where Ptp is transpulmonary pressure, Palv is alveolar pressure, and Pip is intrapleural pressure.
Physiology
Since atmospheric pressure is relatively constant, pressure in the lungs must be higher or lower than atmospheric pressure for air to flow between the atmosphere and the alveoli.
If 'transpulmonary pressure' = 0 (alveolar pressure = intrapleural pressure), such as when the lungs are removed from the chest cavity or air enters the intrapleural space (a pneumothorax), the lungs collapse as a result of their inherent elastic recoil. Under physiological conditions the transpulmonary pressure is always positive; intrapleural pressure is always negative and relatively large, while alveolar pressure moves from slightly negative to slightly positive as a person breathes. For a given lung volume, the transpulmonary pressure is equal and opposite to the elastic recoil pressure of the lung.
The transpulmonary pressure vs volume curve of inhalation (usually plotted as volume as a function of pressure) is different from that of exhalation, the difference being described as hysteresis. Lung volume at any given pressure during inhalation is less than the lung volume at any given pressure during exhalation.
Measurement
Transpulmonary pressure can be measured by placing pressure transducers. The alveolar pressure is estimated by measuring the pressure in the airways while holding one's breath. The intrapleural pressure is estimated by measuring the pressure inside a balloon placed in the esophagus.
Measurement of transpulmonary pressure assists in spirometry in availing for calculation of static lung compliance. |
https://en.wikipedia.org/wiki/Inferior%20medullary%20velum | The inferior medullary velum (posterior medullary velum) is a thin layer of white substance, prolonged from the white center of the cerebellum, above and on either side of the nodule; it forms the infero-posterior part of the fourth ventricle.
Somewhat semilunar in shape, its convex edge is continuous with the white substance of the cerebellum, while its thin concave margin is apparently free; in reality, however, it is continuous with the epithelium of the ventricle, which is prolonged downward from the posterior medullary velum to the taeniae.
See also
Superior medullary velum |
https://en.wikipedia.org/wiki/Second%20sound | Second sound is a quantum mechanical phenomenon in which heat transfer occurs by wave-like motion, rather than by the more usual mechanism of diffusion. Its presence leads to a very high thermal conductivity. It is known as "second sound" because the wave motion of entropy and temperature is similar to the propagation of pressure waves in air (sound). The phenomenon of second sound was first described by Lev Landau in 1941.
Normal sound waves are fluctuations in the displacement and density of molecules in a substance;
second sound waves are fluctuations in the density of particle-like thermal excitations (rotons and phonons).
Second sound can be observed in any system in which most phonon-phonon collisions conserve momentum, like superfluids and in some dielectric crystals when Umklapp scattering is small.
(Umklapp phonon-phonon scattering exchanges momentum with the crystal lattice, so phonon momentum is not conserved.)
In helium II
Second sound is observed in liquid helium at temperatures below the lambda point, 2.1768 K, where 4He becomes a superfluid known as helium II.
Helium II has the highest thermal conductivity of any known material (several hundred times higher than copper). Second sound can be observed either as pulses or in a resonant cavity.
The speed of second sound is close to zero near the lambda point, increasing to approximately 20 m/s around 1.8 K, about ten times slower than normal sound waves.
At temperatures below 1 K, the speed of second sound in helium II increases as the temperature decreases.
Second sound is also observed in superfluid helium-3 below its lambda point 2.5 mK.
As per the two-fluid, the speed of second sound is given by
where is the temperature, is the entropy, is the specific heat, is the superfluid density and is the normal fluid density. As , , where is the ordinary (or first) sound speed.
In other media
Second sound has been observed in solid 4He and 3He,
and in some dielectric solids such as Bi in the tempe |
https://en.wikipedia.org/wiki/Haplogroup%20S%20%28mtDNA%29 | In human genetics, Haplogroup S is a human mitochondrial DNA (mtDNA) haplogroup found only among Indigenous Australians. It is a descendant of macrohaplogroup N.
Origin
Haplogroup S mtDNA evolved within Australia between 64,000 and 40,000 years ago (51 kya).
Distribution
It is found in the Indigenous Australian population. Haplogroup S2 found in Willandra Lakes human remain WLH4 dated back Late Holocene (3,000-500 years ago).
The following table lists relevant GenBank samples:
Subclades
Tree
This phylogenetic tree of haplogroup S subclades is based on the paper by Mannis van Oven and Manfred Kayser Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation and subsequent published research. The TMRCA for haplogroup S is between 49 and 51 KYA according to Nano Nagle's Aboriginal Australian mitochondrial genome variation – an increased understanding of population antiquity and diversity publication that published in 2017.
S (64-40 kya) in Australia
S1 (53-32 kya) in Australia
S1a (44-29 kya) found in WA, NT, QLD and NSW
S1b (37-22 kya) found in NT, QLD and NSW
S1b1 (30-10 kya) found in NT and QLD
S1b1a (24-6 kya) found in QLD
S1b2 (17-3 kya) found in QLD
S1b3 (20-4 kya) found in QLD and NSW
S2 (44-22 kya) in Australia
S2a (38-18 kya) found in NT, QLD, NSW and TAS
S2a1 (31-12 kya) found in NSW, QLD and TAS
S2a1a (19-6 kya) found in NSW and QLD
S2a2 (38-11 kya) found in NT, QLD and NSW
S2b (42-18 kya) found in WA, NT, QLD and VIC
S2b1(27-9 kya) found in NT, QLD and VIC
S2b2 (37-12 kya) found in WA, NT and QLD
S3 (17-1 kya) found in NT
S4 found in NT
S5 found in WA
S6 found in NSW
See also
Genealogical DNA test
Genetic genealogy
Human mitochondrial genetics
Population genetics |
https://en.wikipedia.org/wiki/Haplogroup%20pre-JT | Haplogroup pre-JT is a human mitochondrial DNA haplogroup (mtDNA). It is also called R2'JT.
Origin
Haplogroup pre-JT is a descendant of the haplogroup R. It is characterised by genetic marker at 4216. The pre-JT clade has two direct descendant lineages, haplogroup JT and haplogroup R2.
Distribution
Subclades
Its subclade is Haplogroup JT, which further divides into Haplogroup J and Haplogroup T.
Tree
See also
Genealogical DNA test
Genetic genealogy
Human mitochondrial genetics
Population genetics |
https://en.wikipedia.org/wiki/List%20of%20flags%20used%20in%20Northern%20Ireland | This is a list of flags used in Northern Ireland.
Official flags
Current
These are the flags used by the British Government, the Northern Ireland Assembly and the Monarch in Northern Ireland.
Former
Local government flags
Current
Former
University flags
Others
GAA colours
GAA county colours are used to represent Irish counties in the Gaelic Athletic Association's inter-county competitions, most notably the All-Ireland Senior Football Championship in Gaelic football and the All-Ireland Senior Hurling Championship in Hurling.
Timeline
See also
Flag of Northern Ireland
Northern Ireland flags issue
List of flags of Ireland
Cross-border flag for Ireland
Coat of arms of Northern Ireland |
https://en.wikipedia.org/wiki/Impact%20parameter | In physics, the impact parameter is defined as the perpendicular distance between the path of a projectile and the center of a potential field created by an object that the projectile is approaching (see diagram). It is often referred to in nuclear physics (see Rutherford scattering) and in classical mechanics.
The impact parameter is related to the scattering angle by
where is the velocity of the projectile when it is far from the center, and is its closest distance from the center.
Scattering from a hard sphere
The simplest example illustrating the use of the impact parameter is in the case of scattering from a sphere. Here, the object that the projectile is approaching is a hard sphere with radius . In the case of a hard sphere, when , and for . When , the projectile misses the hard sphere. We immediately see that . When , we find that
Collision centrality
In high-energy nuclear physics — specifically, in colliding-beam experiments — collisions may be classified according to their impact parameter. Central collisions have , peripheral collisions have , and ultraperipheral collisions (UPCs) have , where the colliding nuclei are viewed as hard spheres with radius .
Because the color force has an extremely short range, it cannot couple quarks that are separated by much more than one nucleon's radius; hence, strong interactions are suppressed in peripheral and ultraperipheral collisions. This means that final-state particle multiplicity (the total number of particles resulting from the collision), is typically greatest in the most central collisions, due to the partons involved having the greatest probability of interacting in some way. This has led to charged particle multiplicity being used as a common measure of collision centrality, as charged particles are much easier to detect than uncharged particles.
Because strong interactions are effectively impossible in ultraperipheral collisions, they may be used to study electromagnetic interactions — |
https://en.wikipedia.org/wiki/Schatten%20norm | In mathematics, specifically functional analysis, the Schatten norm (or Schatten–von-Neumann norm)
arises as a generalization of p-integrability similar to the trace class norm and the Hilbert–Schmidt norm.
Definition
Let , be Hilbert spaces, and a (linear) bounded operator from
to . For , define the Schatten p-norm of as
where
,
using the
operator square root.
If is compact and are separable, then
for
the singular values of , i.e. the eigenvalues of the Hermitian operator .
Properties
In the following we formally extend the range of to with the convention that is the operator norm. The dual index to is then .
The Schatten norms are unitarily invariant: for unitary operators and and ,
They satisfy Hölder's inequality: for all and such that , and operators defined between Hilbert spaces and respectively,
If satisfy , then we have
.
The latter version of Hölder's inequality is proven in higher generality (for noncommutative spaces instead of Schatten-p classes) in.
(For matrices the latter result is found in .)
Sub-multiplicativity: For all and operators defined between Hilbert spaces and respectively,
Monotonicity: For ,
Duality: Let be finite-dimensional Hilbert spaces, and such that , then
where denotes the Hilbert–Schmidt inner product.
Let be two orthonormal basis of the Hilbert spaces , then for
.
Remarks
Notice that is the Hilbert–Schmidt norm (see Hilbert–Schmidt operator), is the trace class norm (see trace class), and is the operator norm (see operator norm).
For the function is an example of a quasinorm.
An operator which has a finite Schatten norm is called a Schatten class operator and the space of such operators is denoted by . With this norm, is a Banach space, and a Hilbert space for p = 2.
Observe that , the algebra of compact operators. This follows from the fact that if the sum is finite the spectrum will be finite or countable with the origin as limit point, and henc |
https://en.wikipedia.org/wiki/Sacral%20anterior%20root%20stimulator | A sacral anterior root stimulator is an implantable medical device enabling patients with a spinal cord lesion to empty their bladders.
History
From 1969 onwards Giles Brindley developed the sacral anterior root stimulator, with successful human trials from the early 1980s onwards. Although both sphincter and detrusor muscles are stimulated at the same time, the slower contraction kinetics of the bladder wall (smooth muscle tissue) compared to the sphincter (striated muscle tissue) mean that voiding occurs between the stimulation pulses, rather than during them.
Description
This device is implanted over the sacral anterior root of the spinal cord; controlled by an external transmitter, it delivers intermittent stimulation which improves the ability to empty the bladder. It may also assist in defecation and also may enable male patients to have a sustained full erection. The device is implanted in one of two regions, either through intrathecal administration or extradurally. It is often performed in conjunction with a dorsal rhizotomy, and many groups believe that the best results are only seen when this procedure is performed alongside the implantation. The rhizotomy will remove sensory reflexes, which in men may include sexual reflexes. For some patients this is a major drawback to the device. For others, the benefits outweigh the downside.
The related procedure of sacral nerve stimulation is to control incontinence in otherwise able-bodied patients. |
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