source stringlengths 31 227 | text stringlengths 9 2k |
|---|---|
https://en.wikipedia.org/wiki/Voltage%20reference | A voltage reference is an electronic device that ideally produces a fixed (constant) voltage irrespective of the loading on the device, power supply variations, temperature changes, and the passage of time. Voltage references are used in power supplies, analog-to-digital converters, digital-to-analog converters, and other measurement and control systems. Voltage references vary widely in performance; a regulator for a computer power supply may only hold its value to within a few percent of the nominal value, whereas laboratory voltage standards have precisions and stability measured in parts per million.
In metrology
The earliest voltage references or standards were wet-chemical cells such as the Clark cell and Weston cell, which are still used in some laboratory and calibration applications.
Laboratory-grade Zener diode secondary solid-state voltage standards used in metrology can be constructed with a drift of about 1 part per million per year.
The value of the "conventional" volt is now maintained by superconductive integrated circuits using the Josephson Effect to get a voltage to an accuracy of 1 parts per billion or better, the Josephson voltage standard. The paper titled, "Possible new effects in superconductive tunnelling", was published by Brian David Josephson in 1962 and earned Josephson the Nobel Prize in Physics in 1973.
Formerly, mercury batteries were much used as convenient voltage references especially in portable instruments such as photographic light meters; mercury batteries had a very stable discharge voltage over their useful life.
Solid state devices
Any semiconductor diode has an exponential voltage/current characteristic that gives an effective "knee" voltage sometimes used as a voltage reference. This voltage ranges from 0.3 V for germanium diodes up to about 3 volts for certain light emitting diodes. These devices have a strong temperature dependence, which may make them useful for temperature measurement or for compensating bias i |
https://en.wikipedia.org/wiki/Immunopathology | Immunopathology is a branch of medicine that deals with immune responses associated with disease. It includes the study of the pathology of an organism, organ system, or disease with respect to the immune system, immunity, and immune responses. In biology, it refers to damage caused to an organism by its own immune response, as a result of an infection. It could be due to mismatch between pathogen and host species, and often occurs when an animal pathogen infects a human (e.g. avian flu leads to a cytokine storm which contributes to the increased mortality rate).
Types of Immunity
In all vertebrates, there are two different kinds of immunities: Innate and Adaptive immunity. Innate immunity is used to fight off non-changing antigens and is therefore considered nonspecific. It is usually a more immediate response than the adaptive immune system, usually responding within minutes to hours. It is composed of physical blockades such as the skin, but also contains nonspecific immune cells such as dendritic cells, macrophages, and basophils. The second form of immunity is Adaptive immunity. This form of immunity requires recognition of the foreign antigen before a response is produced. Once the antigen is recognized, a specific response is produced in order to destroy the specific antigen. Because of its tailored response characteristic, adaptive immunity is considered to be specific immunity. A key part of adaptive immunity that separates it from innate is the use of memory to combat the antigen in the future. When the antigen is originally introduced, the organism does not have any receptors for the antigen so it must generate them from the first time the antigen is present. The immune system then builds a memory of that antigen, which enables it to recognize the antigen quicker in the future and be able to combat it quicker and more efficiently. The more the system is exposed to the antigen, the quicker it will build up its responsiveness. Nested within Adaptive immu |
https://en.wikipedia.org/wiki/Portable%20character%20set | Portable Character Set is a set of 103 characters which, according to the POSIX standard, must be present in any character set. Compared to ASCII, the Portable Character Set lacks some control characters, and does not prescribe any particular value encoding.
The Portable Character Set is a superset of the Basic Execution Character Set as defined by ANSI C.
Character Classes
Characters grouped by their class. |
https://en.wikipedia.org/wiki/Enthalpy%20of%20atomization | In chemistry, the enthalpy of atomization (also atomisation in British English) is the enthalpy change that accompanies the total separation of all atoms in a chemical substance (either an element or a compound). This is often represented by the symbol or All bonds in the compound are broken in atomization and none are formed, so enthalpies of atomization are always positive. The associated standard enthalpy is known as the standard enthalpy of atomization, /(kJ mol−1), at 298.15 K (or 25 degrees Celsius) and 100 kPa.
Definition
Enthalpy of atomization is the amount of enthalpy change when a compound's bonds are broken and the component atoms are separated into single atoms ( or monoatom).
Enthalpy of atomization is denoted by the symbol ΔatH. The enthalpy change of atomization of gaseous H2O is, for example, the sum of the HO–H and H–OH bond dissociation enthalpies.
The enthalpy of atomization of an elemental solid is exactly the same as the enthalpy of sublimation for any elemental solid that becomes a monatomic gas upon evaporation.
When a diatomic element is converted to gaseous atoms, only half a mole of molecules will be needed, as the standard enthalpy change is based purely on the production of one mole of gaseous atoms. When the atoms in the molecule are different isotopes of the same element the calculation becomes non-trivial.
See also
Ionization energy
Electron gain enthalpy |
https://en.wikipedia.org/wiki/Email%20privacy | Email privacy is a broad topic dealing with issues of unauthorized access to, and inspection of, electronic mail, or unauthorized tracking when a user reads an email. This unauthorized access can happen while an email is in transit, as well as when it is stored on email servers or on a user's computer, or when the user reads the message. In countries with a constitutional guarantee of the secrecy of correspondence, whether email can be equated with letterstherefore having legal protection from all forms of eavesdroppingis disputed because of the very nature of email.</ref>
In 2022 a lookback at an 1890 law review article about personal privacy (the "right to be left alone”) noted how "digital technology has been allowed to invade our lives" both by personal choice and behavior, and also by various forms of ongoing monitoring.
An email has to go through potentially untrustworthy intermediate computers (email servers, ISPs) before reaching its destination, and there is no way to verify if it was accessed by an unauthorized entity. Through the process of information being sent from the user's computer to the email service provider, data acquisition is taking place, most of the time without the user knowing. There are certain data collection methods (routers) that are used for data privacy concerns, but there are others that can be harmful to the user. This is different from a letter sealed in an envelope, where, by close inspection of the envelope, it might be possible to determine if it had been previously opened. In that sense, an email is much like a postcard, the contents of which are visible to anyone who handles it.
There are certain technological workarounds that make unauthorized access to email difficult, if not impossible. However, since email messages frequently cross national boundaries, and different countries have different rules and regulations governing who can access an email, email privacy is a complicated issue.
Companies may have email policies |
https://en.wikipedia.org/wiki/Comparison%20of%20accounting%20software | The following comparison of accounting software documents the various features and differences between different professional accounting software, personal and small enterprise software, medium-sized and large-sized enterprise software, and other accounting packages. The comparison only focus considering financial and external accounting functions. No comparison is made for internal/management accounting, cost accounting, budgeting, or integrated MAS accounting.
Free and open source software
Proprietary software
Systems listed on a light purple background are no longer in active development.
Further details
See also
List of personal finance software
List of ERP software packages
Point of sale
Comparison of development estimation software
List of project management software |
https://en.wikipedia.org/wiki/Hector%20DeLuca | Hector F. DeLuca, born in Pueblo, Colorado in 1930, is an emeritus University of Wisconsin–Madison professor and former chairman of the university's biochemistry department. DeLuca is well known for his research in involving Vitamin D, from which several pharmaceutical drugs are derived. He was elected to the United States National Academy of Sciences in 1979.
DeLuca has trained almost 160 graduate students and has more than 150 patents to his name. Licensing of his technology, through the Wisconsin Alumni Research Foundation, has generated tens of millions of dollars in revenue for the university.
In addition, DeLuca is president of Deltanoid Pharmaceuticals, a biotechnology company founded on technology he developed.
He was awarded the Bolton S. Corson Medal of the Franklin Institute in 1985. Three buildings on the Wisconsin campus, including the DeLuca Biochemistry Building, were named in his honor in 2014. |
https://en.wikipedia.org/wiki/Dial%20plan | In telecommunication, a dial plan (or dialing plan) establishes the permitted sequences of digits dialed by telephone subscriber and the manner in which a telephone switch interprets these digits within the definitions of the prevailing telephone numbering plan. Dial plans in the public switched telephone network referred to as dialing procedures.
The collection of permissible digit patterns, so called digit-maps, for a private telephone system or for customer premise equipment, such as an analog telephone adapter (ATA) or an IP phone, is sometimes also called dial plan. A pattern may be as short as a single digit, e.g. for reaching an operator, or as long as a complete international telephone number, including trunk prefixes and international prefixes.
Public switched telephone network (USA)
Local numbers consist of seven digits within a numbering plan area with a single area code. For overlay numbering plans the area code must dialed before the local telephone number.
Long distance dialing requires the dialing of 1, the three-digit area code, and the seven-digit local number.
International numbers of any length are dialing starting with 011.
Similarly, telephony service operators may provide dialing sequences for special services, such as directory assistance and emergency services.
Private telephone systems
PBX equipment, carrier switching systems, or end-user telephones may specify a variable-length dial plan or a fixed-length dial plan.
In private branch exchanges in the U.S. a dialing plan may specify the addresses of internal extension, as numbers of two, three, or four digits.
Dialing telephone numbers of the PSTN often requires the dialing of 9 on PBX systems to reach an outside line.
Digit maps
Analog telephone adapters, IP phones, and many other VoIP media gateways have configuration options that establish the digit sequences that can be dialed with the equipment. The dial plan of these devices is established by a digit map.
The following syntax m |
https://en.wikipedia.org/wiki/Data%20buffer | In computer science, a data buffer (or just buffer) is a region of a memory used to store data temporarily while it is being moved from one place to another. Typically, the data is stored in a buffer as it is retrieved from an input device (such as a microphone) or just before it is sent to an output device (such as speakers). However, a buffer may be used when data is moved between processes within a computer. That is comparable to buffers in telecommunication. Buffers can be implemented in a fixed memory location in hardware or by using a virtual data buffer in software that points at a location in the physical memory.
In all cases, the data stored in a data buffer are stored on a physical storage medium. A majority of buffers are implemented in software, which typically use the faster RAM to store temporary data because of the much faster access time compared with hard disk drives. Buffers are typically used when there is a difference between the rate at which data is received and the rate at which it can be processed, or in the case that these rates are variable, for example in a printer spooler or in online video streaming. In the distributed computing environment, data buffer is often implemented in the form of burst buffer, which provides distributed buffering service.
A buffer often adjusts timing by implementing a queue (or FIFO) algorithm in memory, simultaneously writing data into the queue at one rate and reading it at another rate.
Applications
Buffers are often used in conjunction with I/O to hardware, such as disk drives, sending or receiving data to or from a network, or playing sound on a speaker. A line to a rollercoaster in an amusement park shares many similarities. People who ride the coaster come in at an unknown and often variable pace, but the roller coaster will be able to load people in bursts (as a coaster arrives and is loaded). The queue area acts as a buffer—a temporary space where those wishing to ride wait until the ride is availab |
https://en.wikipedia.org/wiki/Elastica%20theory | The elastica theory is a theory of mechanics of solid materials developed by Leonhard Euler that allows for very large scale elastic deflections of structures.
Euler (1744) and Jakob Bernoulli developed the theory for elastic lines (yielding the solution known as the elastica curve) and studied buckling. Certain situations can be solved exactly by elliptic functions. Later elastica theory was generalized together by the Cosserat brothers François and Eugene into a geometric theory with intrinsic directions at each point (1907).
Elastica theory is an example of bifurcation theory. For most boundary conditions several solutions exist simultaneously.
When small deflections of a structure are to be analyzed, elastica theory is not required and an approximate solution may be found using the simpler linear elasticity theory or (for 1-dimensional components) beam theory.
A modern treatise of the planar elastica with full account of bifurcation and instability has been recently presented by Bigoni.
See also
Finite strain theory |
https://en.wikipedia.org/wiki/The%20Real%20Eve | The Real Eve: Modern Man's Journey Out of Africa is a popular science book about the evolution of modern humans written by British geneticist Stephen Oppenheimer.
The book is largely based on the "out of Africa" theory of human origins. Oppenheimer uses information from various disciplines including genetics, archaeology, anthropology and linguistics to synthesize theories on the origin of modern humans and their subsequent dispersal around the world.
The Eve in the title refers to Mitochondrial Eve, a name used for the most recent common ancestor of all humans in the matrilineal (mother to daughter) line of descent.
Book
The book was initially published under a number of different titles including Out of Africa's Eden: the peopling of the world in January 2003, and The Real Eve: Modern Man's Journey Out of Africa in June 2003.
Synopsis
In the book, Oppenheimer supports the theory that modern humans first emerged in Africa and that modern human behavior emerged in Africa prior to the out of Africa migration.
Oppenheimer writes that there was only one migration out of Africa that contributed to the peopling of the rest of the world. Oppenheimer believes that anatomically modern humans crossed the Red Sea from the Horn of Africa and followed the "southern coastal route" once in Asia. Thus Oppenheimer is opposed to the theory that there was another out of Africa migration using a northern route along the Nile and into the Levant as suggested by Lahr and Foley 1994. The book also supports the theory that modern humans were in South Asia during the Toba catastrophe.
Oppenheimer uses familiar names to describe genetic lineages. The biblical analogies of Adam and Eve are used to describe the most recent common ancestors via mitochondrial DNA and the y-chromosome. Other male lineages are described as Cain, Abel and Seth. Mitochondrial DNA haplogroups are frequently described using female names from regions where the haplogroups are common. For example, the haplogrou |
https://en.wikipedia.org/wiki/Adelphogamy | Adelphogamy is a form of sexual partnership between sibling eukaryotes, especially in some species of fungi, flowering plants or ants, or in humans. In flowering plants, adelphogamy refers to sibling pollination: pollen and stigma belong to two individuals which derives from same mother plant.
In sociology, the term adelphogamy or adelphic polyandry may also refer to fraternal polyandry, or to an incestuous relationship between a brother and sister.
See also
Incest between twins
List of coupled siblings |
https://en.wikipedia.org/wiki/ROMK | The renal outer medullary potassium channel (ROMK) is an ATP-dependent potassium channel (Kir1.1) that transports potassium out of cells. It plays an important role in potassium recycling in the thick ascending limb (TAL) and potassium secretion in the cortical collecting duct (CCD) of the nephron. In humans, ROMK is encoded by the KCNJ1 (potassium inwardly-rectifying channel, subfamily J, member 1) gene. Multiple transcript variants encoding different isoforms have been found for this gene.
Function
Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier type potassium channel. It is inhibited by internal ATP and probably plays an important role in potassium homeostasis. The encoded protein has a greater tendency to allow potassium to flow into a cell rather than out of a cell, which has (hence the term "inwardly rectifying" referring to corresponding currents in electrophysiology, but has limited physiological relevance). ROMK was identified as the pore-forming component of the mitochondrial ATP-sensitive potassium (mitoKATP) channel, known to play a critical role in cardioprotection against ischemic-reperfusion injury in the heart as well as in the protection against hypoxia-induced brain injury from stroke or other ischemic attacks.
Klotho is a beta-glucuronidase-like enzyme that activates ROMK by removal of sialic acid.
Clinical significance
Mutations in this gene have been associated with antenatal Bartter syndrome, which is characterized by salt wasting, hypokalemic alkalosis, hypercalciuria, and low blood pressure.
Role in hypokalemia and magnesium deficiency
The ROMK channels are inhibited by magnesium in the nephron's normal physiologic state. In states of hypokalemia (a state of potassium deficiency), concurrent magnesium deficiency results in a state of hypokalemia that may be more difficult t |
https://en.wikipedia.org/wiki/Glucose%20syrup | Glucose syrup, also known as confectioner's glucose, is a syrup made from the hydrolysis of starch. Glucose is a sugar. Maize (corn) is commonly used as the source of the starch in the US, in which case the syrup is called "corn syrup", but glucose syrup is also made from potatoes and wheat, and less often from barley, rice and cassava.p. 21
Glucose syrup containing over 90% glucose is used in industrial fermentation, but syrups used in confectionery contain varying amounts of glucose, maltose and higher oligosaccharides, depending on the grade, and can typically contain 10% to 43% glucose. Glucose syrup is used in foods to sweeten, soften texture and add volume. By converting some glucose in corn syrup into fructose (using an enzymatic process), a sweeter product, high fructose corn syrup can be produced.
Glucose syrup was first made in 1811 in Russia by Gottlieb Kirchhoff using heat and sulfuric acid.
Types
Depending on the method used to hydrolyse the starch and on the extent to which the hydrolysis reaction has been allowed to proceed, different grades of glucose syrup are produced, which have different characteristics and uses. The syrups are broadly categorised according to their dextrose equivalent (DE). The further the hydrolysis process proceeds, the more reducing sugars are produced, and the higher the DE. Depending on the process used, glucose syrups with different compositions, and hence different technical properties, can have the same DE.
Confectioner's syrup
The original glucose syrups were manufactured by acid hydrolysis of corn starch at high temperature and pressure. The typical product had a DE of 42, but quality was variable due to the difficulty of controlling the reaction. Higher DE syrups made by acid hydrolysis tend to have a bitter taste and a dark colour, due to the production of hydroxymethylfurfural and other byproducts.p. 26 This type of product is now manufactured using a continuous converting process and is still widely used du |
https://en.wikipedia.org/wiki/Medical%20education | Medical education is education related to the practice of being a medical practitioner, including the initial training to become a physician (i.e., medical school and internship) and additional training thereafter (e.g., residency, fellowship, and continuing medical education).
Medical education and training varies considerably across the world. Various teaching methodologies have been used in medical education, which is an active area of educational research.
Medical education is also the subject-didactic academic field of educating medical doctors at all levels, including entry-level, post-graduate, and continuing medical education. Specific requirements such as entrustable professional activities must be met before moving on in stages of medical education.
Common techniques and evidence base
Medical education applies theories of pedagogy specifically in the context of medical education. Medical education has been a leader in the field of evidence-based education, through the development of evidence syntheses such as the Best Evidence Medical Education collection, formed in 1999, which aimed to "move from opinion-based education to evidence-based education". Common evidence-based techniques include the Objective structured clinical examination (commonly known as the 'OSCE) to assess clinical skills, and reliable checklist-based assessments to determine the development of soft skills such as professionalism. However, there is a persistence of ineffective instructional methods in medical education, such as the matching of teaching to learning styles and Edgar Dales' "Cone of Learning".
Entry-level education
Entry-level medical education programs are tertiary-level courses undertaken at a medical school. Depending on jurisdiction and university, these may be either undergraduate-entry (most of Europe, Asia, South America and Oceania), or graduate-entry programs (mainly Australia, Philippines and North America). Some jurisdictions and universities provide both u |
https://en.wikipedia.org/wiki/Embedded%20C%2B%2B | Embedded C++ (EC++) is a dialect of the C++ programming language for embedded systems. It was defined by an industry group led by major Japanese central processing unit (CPU) manufacturers, including NEC, Hitachi, Fujitsu, and Toshiba, to address the shortcomings of C++ for embedded applications. The goal of the effort is to preserve the most useful object-oriented features of the C++ language yet minimize code size while maximizing execution efficiency and making compiler construction simpler. The official website states the goal as "to provide embedded systems programmers with a subset of C++ that is easy for the average C programmer to understand and use".
Differences from C++
Embedded C++ excludes some features of C++.
Some compilers, such as those from Green Hills and IAR Systems, allow certain features of ISO/ANSI C++ to be enabled in Embedded C++. IAR Systems calls this "Extended Embedded C++".
Compilation
An EC++ program can be compiled with any C++ compiler. But, a compiler specific to EC++ may have an easier time doing optimization.
Compilers specific to EC++ are provided by companies such as:
IAR Systems
Freescale Semiconductor, (spin-off from Motorola in 2004 who had acquired Metrowerks in 1999)
Tasking Software, part of Altium Limited
Green Hills Software
Criticism
The language has had a poor reception with many expert C++ programmers. In particular, Bjarne Stroustrup says, "To the best of my knowledge EC++ is dead (2004), and if it isn't it ought to be." In fact, the official English EC++ website has not been updated since 2002. Nevertheless, a restricted subset of C++ (based on Embedded C++) has been adopted by Apple Inc. as the exclusive programming language to create all I/O Kit device drivers for Apple's macOS, iPadOS and iOS operating systems of the popular Macintosh, iPhone, and iPad products. Apple engineers felt the exceptions, multiple inheritance, templates, and runtime type information features of standard C++ were either insuffici |
https://en.wikipedia.org/wiki/Geitonogamy | Geitonogamy (from Greek geiton (γείτων) = neighbor + gamein (γαμεῖν) = to marry) is a type of self-pollination. Geitonogamous pollination is sometimes distinguished from the fertilizations that can result from it, geitonogamy. If a plant is self-incompatible, geitonogamy can reduce seed production.
Geitonogamy is when pollen is exported using a vector (pollinator or wind) out of one flower but only to another flower on the same plant. It is a form of self-fertilization.
In flowering plants, pollen is transferred from a flower to another flower on the same plant, and in animal pollinated systems this is accomplished by a pollinator visiting multiple flowers on the same plant. Geitonogamy is also possible within species that are wind-pollinated, and may actually be a quite common source of self-fertilized seeds in self-compatible species. It also occurs in monoecious gymnosperms. Although geitonogamy is functionally cross-pollination involving a pollinating agent, genetically it is similar to autogamy since the pollen grains come from the same plant.
Monoecious plants like maize show geitonogamy. Geitonogamy is not possible for strictly dioecious plants, namely those with separate male and female flowers on different plants.
See also
Plant reproductive morphology
Self-fertilization
Autogamy Depression |
https://en.wikipedia.org/wiki/Dynamic%20imaging | Dynamic imaging is the amalgamation of digital imaging, image editing, and workflow automation. It is used to automate the creation of images by zooming, panning, colorize and performing other image processing and color management operations on a copy of a digital master.
Categories
Dynamic imaging technology falls into three categories:
Script dynamic imaging: A shell script is used to automate repeated tasks in programs.
Batch dynamic imaging (IIP based imaging server): An engine is used in batch processing of images.
Real-time dynamic imaging: An imaging server allows realtime rendering of images, text, logos and colorization based on internal and external data sources.
Device transcoding delivers real-time dynamic imaging features to any device or display without the need of predefined templates. Device transcoded imaging can be used for mobile devices or as an engine behind RFID to create visual messages/offers in narrowcasting/1to1 environments without the need of heavy (flash) clients. |
https://en.wikipedia.org/wiki/Kaczmarz%20method | The Kaczmarz method or Kaczmarz's algorithm is an iterative algorithm for solving linear equation systems . It was first discovered by the Polish mathematician Stefan Kaczmarz, and was rediscovered in the field of image reconstruction from projections by Richard Gordon, Robert Bender, and Gabor Herman in 1970, where it is called the Algebraic Reconstruction Technique (ART). ART includes the positivity constraint, making it nonlinear.
The Kaczmarz method is applicable to any linear system of equations, but its computational advantage relative to other methods depends on the system being sparse. It has been demonstrated to be superior, in some biomedical imaging applications, to other methods such as the filtered backprojection method.
It has many applications ranging from computed tomography (CT) to signal processing. It can be obtained also by applying to the hyperplanes, described by the linear system, the method of successive projections onto convex sets (POCS).
Algorithm 1: Kaczmarz algorithm
Let be a system of linear equations, let be the number of rows of A, be the th row of complex-valued matrix , and let be arbitrary complex-valued initial approximation to the solution of . For compute:
where and denotes complex conjugation of .
If the system is consistent, converges to the minimum-norm solution, provided that the iterations start with the zero vector.
A more general algorithm can be defined using a relaxation parameter
There are versions of the method that converge to a regularized weighted least squares solution when applied to a system of inconsistent equations and, at least as far as initial behavior is concerned, at a lesser cost than other iterative methods, such as the conjugate gradient method.
Algorithm 2: Randomized Kaczmarz algorithm
In 2009, a randomized version of the Kaczmarz method for overdetermined linear systems was introduced by Thomas Strohmer and Roman Vershynin in which the i-th equation is selected randomly with prob |
https://en.wikipedia.org/wiki/Demetrios%20Christodoulou | Demetrios Christodoulou (; born 19 October 1951) is a Greek mathematician and physicist, who first became well known for his proof, together with Sergiu Klainerman, of the nonlinear stability of the Minkowski spacetime of special relativity in the framework of general relativity. Christodoulou is a 1993 MacArthur Fellow.
Early life
Christodoulou was born in Athens and received his doctorate in physics from Princeton University in 1971 under the direction of John Archibald Wheeler. After temporary positions at Caltech, CERN, and the Max Planck Institute for Physics, he became professor of mathematics, first at Syracuse University, then at the Courant Institute, and at Princeton University, before taking up his last position as professor of mathematics and physics at the ETH Zurich in Switzerland. He is emeritus professor since January 2017. He holds dual Greek and U.S. citizenship.
Achievements
In 1993, he published a book coauthored with Klainerman in which their proof of the stability result is laid out in detail. In that year, he was named a MacArthur Fellow. In 1991, he published a paper which shows that the test masses of a gravitational wave detector suffer permanent relative displacements after the passage of a gravitational wave train, an effect which has been named "nonlinear memory effect". In the period 1987–1999 he published a series of papers on the gravitational collapse of a spherically symmetric self-gravitating scalar field and the formation of black holes and associated spacetime singularities. He also showed that, contrary to what had been expected, singularities which are not hidden in a black hole also occur. However, he then showed that such "naked singularities" are unstable.
In 2000, Christodoulou published a book on general systems of partial differential equations deriving from a variational principle (or "action principle"). In 2007, he published a book on the formation of shock waves in 3-dimensional fluids. In 2009 he published a b |
https://en.wikipedia.org/wiki/Hypoxia-inducible%20factor | Hypoxia-inducible factors (HIFs) are transcription factors that respond to decreases in available oxygen in the cellular environment, or hypoxia. They are only present in parahoxozoan animals.
Discovery
The HIF transcriptional complex was discovered in 1995 by Gregg L. Semenza and postdoctoral fellow Guang Wang. In 2016, William Kaelin Jr., Peter J. Ratcliffe and Gregg L. Semenza were presented the Lasker Award for their work in elucidating the role of HIF-1 in oxygen sensing and its role in surviving low oxygen conditions. In 2019, the same three individuals were jointly awarded the Nobel Prize in Physiology or Medicine for their work in elucidating how HIF senses and adapts cellular response to oxygen availability.
Structure
Oxygen-breathing species express the highly conserved transcriptional complex HIF-1, which is a heterodimer composed of an alpha and a beta subunit, the latter being a constitutively-expressed aryl hydrocarbon receptor nuclear translocator (ARNT). HIF-1 belongs to the PER-ARNT-SIM (PAS) subfamily of the basic helix-loop-helix (bHLH) family of transcription factors. The alpha and beta subunit are similar in structure and both contain the following domains:
N-terminus – a bHLH domain for DNA binding
central region – Per-ARNT-Sim (PAS) domain, which facilitates heterodimerization
C-terminus – recruits transcriptional coregulatory proteins
Members
The following are members of the human HIF family:
Function
HIF1α expression in haematopoietic stem cells explains the quiescence nature of stem cells for being metabolically maintaining at a low rate so as to preserve the potency of stem cells for long periods in a life cycle of an organism.
The HIF signaling cascade mediates the effects of hypoxia, the state of low oxygen concentration, on the cell. Hypoxia often keeps cells from differentiating. However, hypoxia promotes the formation of blood vessels, and is important for the formation of a vascular system in embryos and tumors. The hyp |
https://en.wikipedia.org/wiki/Basic%20helix%E2%80%93loop%E2%80%93helix | A basic helix–loop–helix (bHLH) is a protein structural motif that characterizes one of the largest families of dimerizing transcription factors. The word "basic" does not refer to complexity but to the chemistry of the motif because transcription factors in general contain basic amino acid residues in order to facilitate DNA binding.
bHLH transcription factors are often important in development or cell activity. For one, BMAL1-Clock (also called ARNTL) is a core transcription complex in the molecular circadian clock. Other genes, like c-Myc and HIF-1, have been linked to cancer due to their effects on cell growth and metabolism.
Structure
The motif is characterized by two α-helices connected by a loop. In general, transcription factors (including this type) are dimeric, each with one helix containing basic amino acid residues that facilitate DNA binding. In general, one helix is smaller, and due to the flexibility of this loop, allows dimerization by folding and packing against another helix. The larger helix typically contains the DNA-binding regions. bHLH proteins typically bind to a consensus sequence called an E-box, CANNTG. The canonical E-box is CACGTG (palindromic), however some bHLH transcription factors, notably those of the bHLH-PAS family, bind to related non-palindromic sequences, which are similar to the E-box. bHLH TFs may homodimerize or heterodimerize with other bHLH TFs and form a large variety of dimers, each one with specific functions.
Examples
A phylogenetic analysis suggested that bHLH proteins fall into 6 major groups, indicated by letters A through F. Examples of transcription factors containing a bHLH include:
Group A
MyoD
Myf5
Beta2/NeuroD1
Scl, also known as Tal1
proneural bHLH genes like p-CaMKII, and .
Neurogenins
Group B
MAX
C-Myc, N-Myc
TCF4 (Transcription Factor 4)
Group C
These proteins contain two additional PAS domains after the bHLH domain.
AhR
BMAL-1-CLOCK
HIF
NPAS1, NPAS3, MOP5
Group D
EMC
Group |
https://en.wikipedia.org/wiki/Small%20t%20intron | Plasmid vectors are circular strands of DNA, found in virions, that are used in genetic engineering to integrate new genes into a host cell genome.
The small T intron is an intron, that is used in some plasmid vectors, in order to induce gene expression in mammalian cells.
Function
The function of this intron in the vectors is unknown, but it is theorized that it might be involved in splicing or translation efficiency.
Vectors such as pME18s contain it. |
https://en.wikipedia.org/wiki/Clifford%20Martin%20Will | Clifford Martin Will (born 1946) is a Canadian-born theoretical physicist noted for his contributions to general relativity.
Life and work
Will was born in Hamilton, Ontario. In 1968, he earned a B.Sc. from McMaster University. At Caltech, he studied under Kip Thorne, earning his Ph.D. in 1971. He has taught at the University of Chicago and Stanford University, and in 1981 joined the faculty of Washington University in St. Louis. In 2012, he moved to a faculty position at the University of Florida.
Will's theoretical work has centered on post-Newtonian expansions of approximate solutions to the Einstein field equation, a notoriously difficult area which forms the theoretical underpinnings essential for such achievements as the indirect verification by Russell Hulse and Joseph Taylor of the existence of gravitational radiation from observations of a binary pulsar.
Will's book reviewing experimental tests of general relativity is widely regarded as the essential resource for research in this area; his popular book on the same subject was listed by The New York Times as one of the 200 best books published in 1986.
Will was a Guggenheim Fellow for the academic year 1996–1997. From 2009 to 2018, Will was the editor-in-chief of IOP Publishing's journal Classical and Quantum Gravity.
Honors and awards
He was elected a Fellow of the American Physical Society in 1989 and elected to the National Academy of Sciences in 2007.
In 2019, Will received the Albert Einstein Medal, awarded each year since 1979 by the Albert Einstein Society in Bern, Switzerland, for his "important contributions to General Relativity, in particular including the Post-Newtonian expansions of approximate solutions of the Einstein field equations and their confrontation with experiments."
Bibliographic information
According to the NASA ADS database, the h-index of Professor Will is 57.
Selected works
(original publication date 1986) |
https://en.wikipedia.org/wiki/Daz%20Studio | Daz Studio is a free media design software developed by Daz 3D. Daz Studio is a 3D scene creation and rendering application that can be used to produce images as well as videos. Renders can be done by leveraging either the 3Delight render engine, or the Iray render engine, both of which can be included for free with Daz Studio, or with a variety of purchasable add-on render engine plugins for Daz Studio from various vendors and companies.
Daz Studio also supports the import and export of various file formats for 3D objects and animations to allow for the use of other 3D content within Daz Studio, as well as to get content out of Daz Studio for use in other 3D applications.
In 2017, Daz 3D also began offering Hexagon and Daz Studio together for free.
Genesis figure technology
One of the main differences between Daz Studio and other software applications such as Poser is that Daz 3D has also included support for its various generations of the "Genesis" technology, which is used as the basis for its human figures.
Daz 3D has had many versions of its human figures and characters, but in 2011, they launched a significant change in the underlying technology. Instead of each figure being designed individually, Daz 3D moved to their Genesis platform, in which figures were derived as morphs from the base mesh. Two of the key differences that this technology created were: The ability for characters to be blended into a huge variety of shapes; and since these shapes were all derived from a common base, add-on content like clothing, hair, and additional morphs would not only work on all characters but could actually change with the characters.
The Genesis platform has gone through several versions since its launch in 2011:
Genesis 2: One of the shortcomings of the Genesis platform was that although it allowed for extremely flexible characters and clothing, it also toned down some of the elements that made a male or female figure unique. Genesis 2 changed this by split |
https://en.wikipedia.org/wiki/North%20%26%20South%20%28video%20game%29 | North & South is a strategy action game released in 1989 for the Amiga, and Atari ST and ported to the Nintendo Entertainment System, Amstrad CPC, MSX, MS-DOS, Commodore 64 and ZX Spectrum. It was developed and published by Infogrames.
North & South is an offshoot of the Belgian comic series Les Tuniques Bleues (by Raoul Cauvin and Louis Salverius/Willy Lambillotte, from Dupuis) which is based on the American Civil War. The player basically acts out the Civil War, choosing to play as either the North or the South. The player may choose to start the game year from 1861 (the year the Civil War erupted) to 1864. Each year has a different array of armies and states that each side starts with.
North & South contains humorous elements, such as parodies of national anthems, which are accessible when the player selects one of the different languages supported by the game: (English, French, Spanish, German or Italian).
Gameplay
Taking a simplified board interface, the game features a strategic map of the United States separated into states and territories, where army units are moved around. In each state which has a railway station, there is a fort, the capture of which leads to the player overtaking the whole state. Otherwise, capturing a state involves simple movement, unless there is an enemy army present on the state's title. Armies can be reinforced in two ways. By turning on an option at the main menu the player controlling the state of North Carolina will get periodic reinforcements by ship. Also, railways generate money which in turn generates soldiers. Moving their army units, the player may expand westwards into unoccupied territory. If two antagonistic armies clash, it will result in a battle.
Normally, battle is resolved in a real time action element. However, there is an option on the main menu where the player can turn off in-game missions and battles so that game-play is as in a board game. Whenever opposing armies meet in board-game mode, the results |
https://en.wikipedia.org/wiki/Ancyromonas | Ancyromonas is a genus of basal Eukaryote consisting of heterotrophic flagellates.
It includes the species Ancyromonas sigmoides, first described by Saville Kent in 1880. The genus was rediscovered in modern times by Hänel in 1979.
They are about 5 μm long and live in both marine and freshwater habitats with a global distribution.
In 2008, Cavalier-Smith et. al proposed the reassignment of all known species of Ancyromonas into a new genus, Planomonas. Planomonas has since been described as a junior synonym of Ancyromonas. Ancyromonas does not belong to any of the eukaryotic supergroups, and they appear more basal than Malawimonas, placing them in Loukouzoa, possibly relatives of podiates, and depending on the placement of the root position of the Eukaryotes. |
https://en.wikipedia.org/wiki/Hemimastigophora | Hemimastigophora is a group of single-celled eukaryotic organisms including the Spironemidae, first identified in 1988. Over the next 30 years, different authors proposed placing these organisms in various branches of the eukaryotes. In 2018 Lax et al. reported the first genetic information for Spironemidae, and suggest that they are from an ancient lineage of eukaryotes which constitute a separate clade from all other eukaryotic kingdoms. It is potentially related to the Telonemia.
History of classification
Hemimastigophora was established in 1988 by Foissner et al., as a new phylum with a single family, Spironemidae. Its placement on the eukaryote tree of life was unclear, but the authors suggested that the structure of its pellicle and cell nucleus indicated a close relationship with Euglenozoa. For 30 years after the description of the group, no genetic information was available. During that time, researchers proposed that it should be classified in, or near, an assortment of other groups, including the alveolates, apusomonads, ancyromonads, and Rhizaria.
In an article published in 2018, Lax et al. announced that a new hemimastigophoran species, Hemimastix kukwesjijk, had been discovered in a Nova Scotian soil sample, and successfully cultivated in the laboratory. A second hemimastigophoran, a new species of Spironema, was found in the same sample. Phylogenomic analyses of the two organisms suggest that Hemimastigophora is a very ancient lineage, which diverged from the other eukaryotes at such an early date that the group should be classified at the supra-kingdom level. |
https://en.wikipedia.org/wiki/DesktopBSD | DesktopBSD is a Unix-derived, desktop-oriented operating system based on FreeBSD. Its goal was to combine the stability of FreeBSD with the ease-of-use of K Desktop Environment 3, which is the default graphical user interface.
History and development
DesktopBSD is essentially a customized installation of FreeBSD and is not a fork of it. DesktopBSD was always based on FreeBSD's latest stable branch but incorporated certain customized, pre-installed software such as KDE and DesktopBSD utilities and configuration files.
A common misconception about DesktopBSD was that it was intended as a rival to TrueOS as a BSD-based desktop distribution, since they were similar in structure and goals. However, DesktopBSD was started approximately one year before the PC-BSD project, despite the fact that the first PC-BSD release came out before DesktopBSD's. Neither project intended to rival the other and they were completely independent with distinctive features and intended outcomes: for example, DesktopBSD uses ports and packages for additional software installation, whereas PC-BSD introduced PBIs.
The final release was 1.7 which was made available on 7 September 2009. The release announcement stated "This is the last and final release of the DesktopBSD project" because the lead developer could no longer contribute the time required to maintain it.
In May 2010 DesktopBSD was restarted under new leadership
though development and announcements stopped soon afterwards. On 10 March 2013, a forum post appeared announcing that the project was "in the process of being revived." The roadmap for DesktopBSD 2.0 was announced in September 2015 on the DesktopBSD site, along with posted screenshots of a GNOME3-based desktop.
Graphical features
Installer allowing to partition disks and create users
Tool for managing, installing and updating software using FreeBSD ports system
Management of network interfaces and mounting/unmounting drives
1.7 release
The 1.7 release includes
FreeBS |
https://en.wikipedia.org/wiki/Hydrolyzed%20vegetable%20protein | Hydrolyzed vegetable protein (HVP) products are foodstuffs obtained by protein hydrolysis and are used as ingredients to create a bouillon (broth) taste without the vegetables, bones, simmering, or other standard elements of creating bouillon from scratch.
Regarding the production process, a distinction can be made between acid-hydrolyzed vegetable protein (aHVP), enzymatically produced HVP, and other seasonings, e.g., fermented soy sauce. Hydrolyzed vegetable protein products are particularly used to round off the taste of soups, sauces, meat products, snacks, and other dishes, as well as for the production of ready-to-cook soups and bouillons.
History
Food technologists have long known that protein hydrolysis produces a meat bouillon-like odor and taste. In 1831, Berzelius obtained products having a meat bouillon taste when hydrolysing proteins with hydrochloric acid. Julius Maggi produced acid-catalyzed hydrolyzed vegetable protein industrially for the first time in 1886.
In 1906, Fischer found that amino acids contributed to the specific taste. In 1954, D. Phillips found that the bouillon odor required the presence of proteins containing threonine. Another important substance giving a characteristic taste is glutamic acid.
Manufacture
Almost all products rich in protein are suitable for the production of HVP. Today, it is made mainly from protein resources of vegetable origin, such as defatted oil seeds (soybean meal, grapeseed meal) and protein from maize (Corn gluten meal), wheat (gluten), pea, and rice. The process and the feedstock determines the organoleptic properties of the end product. Proteins consist of chains of amino acids joined through amide bonds. When subjected to hydrolysis (hydrolyzed), the protein is broken down into its component amino acids.
In aHVP, hydrochloric acid is used for hydrolysis. The remaining acid is then neutralized by mixing with an alkali such as sodium hydroxide, which leaves behind table salt, which comprises up to 20% |
https://en.wikipedia.org/wiki/Sagittal%20plane | The sagittal plane (; also known as the longitudinal plane) is an anatomical plane that divides the body into right and left sections. It is perpendicular to the transverse and coronal planes. The plane may be in the center of the body and divide it into two equal parts (mid-sagittal), or away from the midline and divide it into unequal parts (para-sagittal).
The term sagittal was coined by Gerard of Cremona.
Variations in terminology
Examples of sagittal planes include:
The terms median plane or mid-sagittal plane are sometimes used to describe the sagittal plane running through the midline. This plane cuts the body into halves (assuming bilateral symmetry), passing through midline structures such as the navel and spine. It is one of the planes which, combined with the Umbilical plane, defines the four quadrants of the human abdomen.
The term parasagittal is used to describe any plane parallel or adjacent to a given sagittal plane. Specific named parasagittal planes include:
The midclavicular line crosses through the clavicle.
Lateral sternal and parasternal planes.
The term sagittal is derived from the Latin word sagitta, meaning "arrow". An image of an arrow piercing a body and passing from front (anterior) to back (posterior) on a parabolic trajectory would be one way to demonstrate the derivation of the term. Another explanation would be the notching of the sagittal suture posteriorly by the lambdoidal suture —similar to feathers on an arrow.
Sagittal axis or anterior-posterior axis is the axis perpendicular to the coronal plane, i.e., the one formed by the intersection of the sagittal and the transversal planes
Coronal axis, medial-lateral axis, or frontal axis is the axis perpendicular to the sagittal plane, i.e., the one formed by the intersection of the coronal and the transversal planes.
Extension and flexion are the movements of limbs within the sagittal plane.
Abduction and adduction'' are terms for movements of limbs within the coronal plane. |
https://en.wikipedia.org/wiki/Calcium%20caseinate | Calcium caseinate is one of several milk proteins derived from casein in skim and 1% milk. Calcium caseinate has a papery, sweet and overall bland flavor, and is primarily used in meal preparation and fat breakdown. Caseinates are produced by adding an alkali to another derivative of casein, acid casein. The type of caseinate is determined by the cation added alongside the acid casein. Other cations used to form caseinates besides calcium include ammonium, potassium, and sodium.
Calcium caseinate contains about 17% glutamic acid. This provides many health benefits such as treating low blood sugar, improving memory and focus, boosting the immune system and treating intellectual disorders. Calcium caseinate is also soluble and does not clot in the stomach.
Calcium caseinate is mostly composed of 3.5% moisture, 1.0% fat, 90.9% protein, 0.1% lactose, 4.5% ash, although this may vary slightly by manufacturer. Calcium caseinate is semi-soluble in water, contrary to acid casein and rennet casein which are not soluble in water. Sodium caseinate is more water soluble than calcium caseinate, due to its polarity.
Physical properties
Caseins are found in milk which is held together by colloidal calcium phosphate. Calcium caseinate is generally stable at a pH above 5.7, and appears as a milky liquid. This is unlike ammonium, potassium, and sodium caseinates, which are practically clear. At a neutral or acidic pH, casein is relatively insoluble in water, and is easily separated from other milk proteins, sugars, and minerals. Casein can be resuspended by alternating the pH levels with NaOH or , resulting in aqueous solutions of sodium caseinate or calcium caseinate. Most caseinates are capable of withstanding temperatures of up to 140°C (284°F), however calcium caseinate is influenced by heat with temperatures as low as 50°C (122°F). Calcium is a divalent cation, allowing it to form bonds with several caseinate anions. The binding of a calcium ion is able to reduce the elect |
https://en.wikipedia.org/wiki/Kepler%20problem | In classical mechanics, the Kepler problem is a special case of the two-body problem, in which the two bodies interact by a central force F that varies in strength as the inverse square of the distance r between them. The force may be either attractive or repulsive. The problem is to find the position or speed of the two bodies over time given their masses, positions, and velocities. Using classical mechanics, the solution can be expressed as a Kepler orbit using six orbital elements.
The Kepler problem is named after Johannes Kepler, who proposed Kepler's laws of planetary motion (which are part of classical mechanics and solved the problem for the orbits of the planets) and investigated the types of forces that would result in orbits obeying those laws (called Kepler's inverse problem).
For a discussion of the Kepler problem specific to radial orbits, see Radial trajectory. General relativity provides more accurate solutions to the two-body problem, especially in strong gravitational fields.
Applications
The Kepler problem arises in many contexts, some beyond the physics studied by Kepler himself. The Kepler problem is important in celestial mechanics, since Newtonian gravity obeys an inverse square law. Examples include a satellite moving about a planet, a planet about its sun, or two binary stars about each other. The Kepler problem is also important in the motion of two charged particles, since Coulomb’s law of electrostatics also obeys an inverse square law. Examples include the hydrogen atom, positronium and muonium, which have all played important roles as model systems for testing physical theories and measuring constants of nature.
The Kepler problem and the simple harmonic oscillator problem are the two most fundamental problems in classical mechanics. They are the only two problems that have closed orbits for every possible set of initial conditions, i.e., return to their starting point with the same velocity (Bertrand's theorem). The Kepler |
https://en.wikipedia.org/wiki/Albularyo | Albularyo or albulario is a Filipino term for a witch doctor, folk healer or medicine man, derived from Spanish herbolario (herbalist). They practice folk medicine and use medicinal plants in their trade.
Overview
the Role and functions
An albularyo is a "folk doctor" commonly found in the more rural areas of the Philippines who heals people using herbs and traditional practices such as hilot or massage. Their services are considered either as a first or as a last resort for addressing illnesses. The albularyo's patient claims that the practitioner have supernatural powers that modern medicine does not provide. This belief makes them more trustworthy than modern medicine practitioners. Aside from practicing folk medicine, the albularyo is also alleged to practice black magic and curse people.
The albularyos practice their trade using prayers called orasyon (from Spanish oracion) and rituals. They also use concoctions made from plant parts such as leaves, bark, roots and oils such as coconut oils. Pangalap is the process of searching for these medicinal plants and pabukal is the preparation of decoctions from said plants. Albularyos also use their own saliva and pieces of papers with writings. The albularyo use tawas (alum) crystals to find out who is causing the ailments in their patients." The may also use candle wax poured in water, eggs, or spirits to divine the cause of the ailments. Some ailments are claimed to be the work of lamang lupa who were unknowingly or knowingly harmed by the patient. The albularyo may then use rituals and prayers to drive away the spirit and therefore remove the sickness from the patient.
See also
Hilot, traditional Filipino medicine that uses massage
Kulam, or Filipino witchcraft
Pagtatawas, or Filipino ritual for the diagnosis of illnesses
Folk medicine |
https://en.wikipedia.org/wiki/Gummosis | Gummosis is the formation of patches of a gummy substance on the surface of certain plants, particularly fruit trees. This occurs when sap oozes from wounds or cankers as a reaction to outside stimuli such as adverse weather conditions, infections, insect problems, or mechanical damage. It is understood as a plant physiological disease.
Damage
Liquefaction of wood pieces, especially young wood, causes disease foci to form under the bark, which secrete a gummy colorless to amber liquid, a plant gum, which then oozes out between the bark pieces on branches and trunk. The gum is composed of various sugar compounds and acids.
Causes
The main causes are physiological disturbances of the tree, which can affect the water balance, among other things. Frost, injuries, but also bacteria and fungi, especially of the genus Hallimasch (Armillaria), can contribute to gum flow. |
https://en.wikipedia.org/wiki/Acoustic%20lubrication | Acoustic lubrication or sonic lubrication occurs when sound (measurable in a vacuum by placing a microphone on one element of the sliding system) permits vibration to introduce separation between the sliding faces. This could happen between two plates or between a series of particles. The frequency of sound required to induce optimal vibration, and thus cause sonic lubrication, varies with the size of the particles (high frequencies will have the desired, or undesired, effect on sand and lower frequencies will have this effect on boulders).
Examples
If there is a dynamic coefficient of friction between two objects of 0.20, and vibration causes them to be in contact only half of the time, that would be equivalent to a constant coefficient of friction of 0.10. This substantial reduction in friction can have a profound effect on the system. According to anecdote, World War II Panzer tank treads may have been lubricated by their own squeak providing a serendipitous example of acoustic lubrication.
Another example occurs during landslides. Most landslides do not involve this effect, but occasionally the frequency of vibrations caused by the landslide is optimal to cause the boulders to vibrate. In this case, feedback causes the boulders to slide much farther and more quickly than typical, which can pose an increased danger to those in their path. One notable feature of such a landslide is that it appears to resemble flowing water, or mud, and not the dry sliding rocks that they were seconds earlier.
Applications
Besides the study of landslides, there could be many other applications for acoustic lubrication, particularly where variable friction is required or traditional lubricants can't be used. One case might be drilling wells (for water, oil, etc.) through sand. The optimal pitch of the sound (measurement of frequency) could reduce the friction between the drill bit and sand considerably.
New razors with a vibrating head may also be an example.
In ficti |
https://en.wikipedia.org/wiki/Inter-Language%20Unification | Inter-Language Unification or ILU is a method for computer systems to exchange data, bridging differences in the way systems represent the various kinds of data. Even if two systems run on the same computer, or on identical computer hardware, many differences arise from the use of different computer languages to build the systems.
The object interfaces provided by ILU hide implementation distinctions between different languages, between different address spaces, and between operating system types. ILU can be used to build multi-lingual object-oriented libraries ("class libraries") with well-specified language-independent interfaces. It can also be used to implement distributed systems. It can also be used to define and document interfaces between the modules of non-distributed programs. ILU interfaces can be specified in either the Object Management Group's CORBA Interface Definition Language (OMG IDL), or ILU's Interface Specification Language (ISL).
History
ILU was developed as an Open Source project at the Xerox Palo Alto Research Center (Xerox PARC) from 1991 until 2000. The last release was 2.0beta1.
From 1997 to 2000, ILU was used as the foundation for experimental work on a "next generation" HTTP protocol by the World Wide Web Consortium's HTTP-NG activity. As a result of this work, a particularly efficient experimental RPC protocol called "w3ng" was developed, along with a way of efficiently multiplexing a single TCP connection into multiple channels in both directions, called "w3mux". The results of the HTTP-NG experiment were presented at the 2000 World Wide Web Conference.
Features
The last release supported the programming languages C++ (Corba2 mapping), ANSI C, Python, Java, and Common Lisp. Contributed support was also available for Modula-3, Guile Scheme, and Perl 5. ILU has been installed on most flavors of UNIX (SunOS, Solaris, HP-UX, AIX, OSF, IRIX, FreeBSD, Linux, LynxOS, SCO Unix, etc.) and MS-Windows (3.1, 95, NT). It supported both th |
https://en.wikipedia.org/wiki/Myelencephalon | The myelencephalon or afterbrain is the most posterior region of the embryonic hindbrain, from which the medulla oblongata develops.
Development
Neural tube to myelencephalon
During fetal development, divisions of the neural tube that give rise to the hindbrain (rhombencephalon) and the other primary vesicles (forebrain and midbrain) occur at 28 days after conception. With the exception of the midbrain, these primary vesicles undergo further differentiation at 5 weeks after conception to form the myelencephalon and the other secondary vesicles.
Myelencephalon to medulla
Final shape differentiation of the myelencephalon into the medulla oblongata can be observed at 20 weeks gestation.
Medulla oblongata
The medulla oblongata is part of the brain stem that serves as the connection of the spinal cord to the brain. It is situated between the pons and the spinal cord.
Function
The medulla oblongata is responsible for several functions of the autonomic nervous system. These functions include:
1) Respiration: monitors the acidity of the blood and sends electrical signals to intercostal muscle tissue to increase their contraction rate in order to oxygenate the blood as needed.
2) Cardiac & Vasomotor Center: monitors and regulates cardiovascular activities by:
Sympathetic excitation in order to increase cardiac output
Parasympathetic inhibition of cardiac output
Affecting blood pressure via vasodilation and vasoconstriction
3) Reflexes
Coughing
Sneezing
Swallowing (palatal)
Vomiting
Gagging (pharyngeal)
Jaw jerk (masseter)
Damage/trauma
Because of its location in the brainstem and its many important roles in the autonomic nervous system, damage to the medulla oblongata is usually fatal. |
https://en.wikipedia.org/wiki/Metencephalon | The metencephalon is the embryonic part of the hindbrain that differentiates into the pons and the cerebellum. It contains a portion of the fourth ventricle and the trigeminal nerve (CN V), abducens nerve (CN VI), facial nerve (CN VII), and a portion of the vestibulocochlear nerve (CN VIII).
Embryology
The metencephalon develops from the higher/rostral half of the embryonic rhombencephalon, and is differentiated from the myelencephalon in the embryo by approximately 5 weeks of age. By the third month, the metencephalon differentiates into its two main structures, the pons and the cerebellum.
Functions
The pons regulates breathing through particular nuclei that regulate the breathing center of the medulla oblongata. The cerebellum works to coordinate muscle movements, maintain posture, and integrate sensory information from the inner ear and proprioceptors in the muscles and joints.
Development
At the early stages of brain development, the brain vesicles that are formed are imperative. Each brain region is characterized by its own specific architecture. These regions of the brain are determined by a combination of transcription factors and the signals that change their expression.
The isthmus is the main organizing center for the tectum and the cerebellum. The tectum is the dorsal part of the metencephalon. The tectum includes the superior and inferior colliculli, which play a part in visual and audio processing. Two of the major genes that affect the metencephalon are Fgf8 and Wnt1, which are both expressed around the isthmus. Fgf8 is also known as Fibroblast Growth Factor 8. It is a protein that is widely thought to be the most important organizing signal. Its main function is to set up and maintain the barrier between the midbrain and hindbrain, specifically between the mesencephalon and metencephalon. It also plays a large role in deciding the structure of the mid- and hindbrain. Wnt1 is a proto-oncogene protein (Wingless-type MMTV integration site fami |
https://en.wikipedia.org/wiki/GABAergic | In molecular biology and physiology, something is GABAergic or GABAnergic if it pertains to or affects the neurotransmitter gamma-aminobutyric acid (GABA). For example, a synapse is GABAergic if it uses GABA as its neurotransmitter, and a GABAergic neuron produces GABA. A substance is GABAergic if it produces its effects via interactions with the GABA system, such as by stimulating or blocking neurotransmission.
A GABAergic or GABAnergic agent is any chemical that modifies the effects of GABA in the body or brain. Some different classes of GABAergic drugs include agonists, antagonists, modulators, reuptake inhibitors and enzymes.
See also
Adenosinergic
Adrenergic
Cannabinoidergic
Cholinergic
Dopaminergic
Glutamatergic
Glycinergic
Histaminergic
Melatonergic
Monoaminergic
Neurotransmission
Opioidergic
Serotonergic |
https://en.wikipedia.org/wiki/Glutamatergic | Glutamatergic means "related to glutamate". A glutamatergic agent (or drug) is a chemical that directly modulates the excitatory amino acid (glutamate/aspartate) system in the body or brain. Examples include excitatory amino acid receptor agonists, excitatory amino acid receptor antagonists, and excitatory amino acid reuptake inhibitors.
See also
Adenosinergic
Adrenergic
Cannabinoidergic
Cholinergic
Dopaminergic
GABAergic
GHBergic
Glycinergic
Histaminergic
Melatonergic
Monoaminergic
Opioidergic
Serotonergic
Sigmaergic |
https://en.wikipedia.org/wiki/Real-time%20kinematic%20positioning | Real-time kinematic positioning (RTK) is the application of surveying to correct for common errors in current satellite navigation (GNSS) systems. It uses measurements of the phase of the signal's carrier wave in addition to the information content of the signal and relies on a single reference station or interpolated virtual station to provide real-time corrections, providing up to centimetre-level accuracy (see DGPS). With reference to GPS in particular, the system is commonly referred to as carrier-phase enhancement, or CPGPS. It has applications in land surveying, hydrographic surveying, and in unmanned aerial vehicle navigation.
Background
The distance between a satellite navigation receiver and a satellite can be calculated from the time it takes for a signal to travel from the satellite to the receiver. To calculate the delay, the receiver must align a pseudorandom binary sequence contained in the signal to an internally generated pseudorandom binary sequence. Since the satellite signal takes time to reach the receiver, the satellite's sequence is delayed in relation to the receiver's sequence. By increasingly delaying the receiver's sequence, the two sequences are eventually aligned.
The accuracy of the resulting range measurement is essentially a function of the ability of the receiver's electronics to accurately process signals from the satellite, and additional error sources such as non-mitigated ionospheric and tropospheric delays, multipath, satellite clock and ephemeris errors.
Carrier-phase tracking
RTK follows the same general concept, but uses the satellite signal's carrier wave as its signal, ignoring the information contained within. RTK uses a fixed base station and a rover to reduce the rover's position error. The base station transmits correction data to the rover.
As described in the previous section, the range to a satellite is essentially calculated by multiplying the carrier wavelength times the number of whole cycles between the sate |
https://en.wikipedia.org/wiki/Thames%20Town | Thames Town () is a new town in Songjiang District, about from central Shanghai. It is named after the River Thames, which flows through London, United Kingdom. The architecture is themed according to British market town styles. There are cobbled streets, Victorian terraces, corner shops and red telephone boxes. High house prices led to few permanent residents moving to the area, causing many of the shops and restaurants to close and the area to become known as a "ghost town".
Description
Thames Town is a part of Songjiang New City, in Songjiang District. The town is from the Songjiang New City station on Shanghai Metro Line 9. The G60 Shanghai–Kunming Expressway, formerly known as the Huhang Expressway, passes to its south.
While Songjiang District is an ancient prefecture which predates by far the establishment of Shanghai, Songjiang New City is a new development, intended to draw population away from central Shanghai. Within this city, one of the objectives for Thames Town was to provide accommodation for the staff of the new universities in adjacent Songjiang University Town. These developments were a part of the One City, Nine Towns initiative, which was passed by the Shanghai Planning Commission in 2001. This policy lasted for the duration of the tenth five year plan (2001–2005). The "one city" of this policy was Songjiang New City, where an English theme was used for Thames Town. The "nine towns" of the policy were each sited in one of the other suburban districts of Shanghai, and each was also given their own theme. Other Western themes used to date are Scandinavian (Luodian), Italian (Pujiang), Spanish (Fengcheng), Canadian (Fengjing), Dutch (Gaoqiao) and German (Anting).
The architectural firm of Atkins was given responsibility for planning Songjiang New City and designing Thames Town. The main developers for the town were Shanghai Songjiang New City Construction and Development, and Shanghai Henghe Real Estate. Thames Town was completed in 2006, occu |
https://en.wikipedia.org/wiki/Commemorative%20plaque | A commemorative plaque, or simply plaque, or in other places referred to as a historical marker, historic marker, or historic plaque, is a plate of metal, ceramic, stone, wood, or other material, typically attached to a wall, stone, or other vertical surface, and bearing text or an image in relief, or both, to commemorate one or more persons, an event, a former use of the place, or some other thing. Many modern plaques and markers are used to associate the location where the plaque or marker is installed with the person, event, or item commemorated as a place worthy of visit. A monumental plaque or tablet commemorating a deceased person or persons, can be a simple form of church monument. Most modern plaques affixed in this way are commemorative of something, but this is not always the case, and there are purely religious plaques, or those signifying ownership or affiliation of some sort. A plaquette is a small plaque, but in English, unlike many European languages, the term is not typically used for outdoor plaques fixed to walls.
Historical
Benin Kingdom
The Benin Empire, which flourished in present-day Nigeria between the thirteenth and nineteenth centuries, had an exceedingly rich sculptural tradition. One of the kingdom's chief sites of cultural production was the elaborate ceremonial court of the Oba (divine king) at the palace in Benin. Among the wide range of artistic forms produced at the court were rectangular brass or bronze plaques. At least a portion of these plaques, which were mainly created from the thirteenth through sixteenth centuries, commemorate significant persons and events associated with the Oba's court, including important battles during Benin's sixteenth century expansionary period.
Medieval Europe
Brass or bronze memorial plaques were produced throughout medieval Europe from at least the early thirteenth through the sixteenth centuries as a form of sepulchral memorial generally inset into the walls of churches or surfaces of tombs |
https://en.wikipedia.org/wiki/Norepinephrine%20transporter | The norepinephrine transporter (NET), also known as noradrenaline transporter (NAT), is a protein that in humans is encoded by the solute carrier family 6 member 2 (SLC6A2) gene.
NET is a monoamine transporter and is responsible for the sodium-chloride (Na+/Cl−)-dependent reuptake of extracellular norepinephrine (NE), which is also known as noradrenaline. NET can also reuptake extracellular dopamine (DA). The reuptake of these two neurotransmitters is essential in regulating concentrations in the synaptic cleft. NETs, along with the other monoamine transporters, are the targets of many antidepressants and recreational drugs. In addition, an overabundance of NET is associated with ADHD. There is evidence that single-nucleotide polymorphisms in the NET gene (SLC6A2) may be an underlying factor in some of these disorders.
Gene
The norepinephrine transporter gene, SLC6A2 is located on human chromosome 16 locus 16q12.2. This gene is encoded by 14 exons. Based on the nucleotide and amino acid sequence, the NET transporter consists of 617 amino acids with 12 membrane-spanning domains. The structural organization of NET is highly homologous to other members of a sodium/chloride-dependent family of neurotransmitter transporters, including dopamine, epinephrine, serotonin and GABA transporters.
Single-nucleotide polymorphisms
A single-nucleotide polymorphism (SNP) is a genetic variation in which a genome sequence is altered by a single nucleotide (A, T, C or G). NET proteins with an altered amino acid sequence (more specifically, a missense mutation) could potentially be associated with various diseases that involve abnormally high or low plasma levels of norepinephrine due to altered NET function. NET SNPs and possible associations with various diseases are an area of focus for many research projects. There is evidence suggesting a relationship between NET SNPs and various disorders such as ADHD psychiatric disorders, postural tachycardia and orthostatic intolerance. The |
https://en.wikipedia.org/wiki/Ramanujan%E2%80%93Nagell%20equation | In mathematics, in the field of number theory, the Ramanujan–Nagell equation is an equation between a square number and a number that is seven less than a power of two. It is an example of an exponential Diophantine equation, an equation to be solved in integers where one of the variables appears as an exponent.
The equation is named after Srinivasa Ramanujan, who conjectured that it has only five integer solutions, and after Trygve Nagell, who proved the conjecture. It implies non-existence of perfect binary codes with the minimum Hamming distance 5 or 6.
Equation and solution
The equation is
and solutions in natural numbers n and x exist just when n = 3, 4, 5, 7 and 15 .
This was conjectured in 1913 by Indian mathematician Srinivasa Ramanujan, proposed independently in 1943 by the Norwegian mathematician Wilhelm Ljunggren, and proved in 1948 by the Norwegian mathematician Trygve Nagell. The values of n correspond to the values of x as:-
x = 1, 3, 5, 11 and 181 .
Triangular Mersenne numbers
The problem of finding all numbers of the form 2b − 1 (Mersenne numbers) which are triangular is equivalent:
The values of b are just those of n − 3, and the corresponding triangular Mersenne numbers (also known as Ramanujan–Nagell numbers) are:
for x = 1, 3, 5, 11 and 181, giving 0, 1, 3, 15, 4095 and no more .
Equations of Ramanujan–Nagell type
An equation of the form
for fixed D, A , B and variable x, n is said to be of Ramanujan–Nagell type. The result of Siegel implies that the number of solutions in each case is finite. By representing with and with , the equation of Ramanujan–Nagell type is reduced to three Mordell curves (indexed by ), each of which has a finite number of integer solutions:
,
,
.
The equation with has at most two solutions, except in the case corresponding to the Ramanujan–Nagell equation. There are infinitely many values of D for which there are two solutions, including .
Equations of Lebesgue–Nagell type
An equation of the form
f |
https://en.wikipedia.org/wiki/HoneyMonkey | HoneyMonkey, short for Strider HoneyMonkey Exploit Detection System, is a Microsoft Research honeypot. The implementation uses a network of computers to crawl the World Wide Web searching for websites that use browser exploits to install malware on the HoneyMonkey computer. A snapshot of the memory, executables and registry of the honeypot computer is recorded before crawling a site. After visiting the site, the state of memory, executables, and registry is recorded and compared to the previous snapshot. The changes are analyzed to determine if the visited site installed any malware onto the client honeypot computer.
HoneyMonkey is based on the honeypot concept, with the difference that it actively seeks websites that try to exploit it. The term was coined by Microsoft Research in 2005. With honeymonkeys it is possible to find open security holes that are not yet publicly known but are being exploited by attackers.
Technology
A single HoneyMonkey is an automated program that tries to mimic the action of a user surfing the net. A series of HoneyMonkeys are run on virtual machines running Windows XP, at various levels of patching — some are fully patched, some fully vulnerable, and others in between these two extremes. The HoneyMonkey program records every read or write of the file system and registry, thus keeping a log of what data was collected by the web-site and what software was installed by it. Once the program leaves a site, this log is analyzed to determine if any malware has been loaded. In such cases, the log of actions is sent for further manual analysis to an external controller program, which logs the exploit data and restarts the virtual machine to allow it to crawl other sites starting in a known uninfected state.
Initiating crawling
Out of the 10 billion plus web pages, there are many legitimate sites that do not use exploit browser vulnerabilities, and to start crawling from most of these sites would be a waste of resources. An initial list was th |
https://en.wikipedia.org/wiki/Isolated%20system | In physical science, an isolated system is either of the following:
a physical system so far removed from other systems that it does not interact with them.
a thermodynamic system enclosed by rigid immovable walls through which neither mass nor energy can pass.
Though subject internally to its own gravity, an isolated system is usually taken to be outside the reach of external gravitational and other long-range forces.
This can be contrasted with what (in the more common terminology used in thermodynamics) is called a closed system, being enclosed by selective walls through which energy can pass as heat or work, but not matter; and with an open system, which both matter and energy can enter or exit, though it may have variously impermeable walls in parts of its boundaries.
An isolated system obeys the conservation law that its total energy–mass stays constant. Most often, in thermodynamics, mass and energy are treated as separately conserved.
Because of the requirement of enclosure, and the near ubiquity of gravity, strictly and ideally isolated systems do not actually occur in experiments or in nature. Though very useful, they are strictly hypothetical.
Classical thermodynamics is usually presented as postulating the existence of isolated systems. It is also usually presented as the fruit of experience. Obviously, no experience has been reported of an ideally isolated system.
It is, however, the fruit of experience that some physical systems, including isolated ones, do seem to reach their own states of internal thermodynamic equilibrium. Classical thermodynamics postulates the existence of systems in their own states of internal thermodynamic equilibrium. This postulate is a very useful idealization.
In the attempt to explain the idea of a gradual approach to thermodynamic equilibrium after a thermodynamic operation, with entropy increasing according to the second law of thermodynamics, Boltzmann’s H-theorem used equations, which assumed a system (for exa |
https://en.wikipedia.org/wiki/Organic%20fertilizer | Organic fertilizers are fertilizers that are naturally produced. Fertilizers are materials that can be added to soil or plants, in order to provide nutrients and sustain growth. Typical organic fertilizers include all animal waste including meat processing waste, manure, slurry, and guano; plus plant based fertilizers such as compost; and biosolids. Inorganic "organic fertilizers" include minerals and ash. The organic-mess refers to the Principles of Organic Agriculture, which determines whether a fertilizer can be used for commercial organic agriculture, not whether the fertilizer consists of organic compounds.
Examples and sources
The main organic fertilizers are, peat, animal wastes, plant wastes from agriculture, and treated sewage sludge.
Minerals
Minerals can be mined from fossil products of animal activity, such as greensand (anaerobic marine deposits), some limestones (fossil shell deposits), and some rock phosphates (fossil guano). Adding limestone or “liming” a soil is a way to raise pH. By raising the pH of a soil, microbial growth can be stimulated, which in turn increases biological processes, enabling nutrients to flow more freely through the soil. When nutrients flow freely they are more accessible to plants and therefore can increase plant health and mass. If the soil is already pH balanced, liming the soil, would be ineffective.
Rock phosphate
Raw Langbeinite
Rockdust
Unprocessed natural potassium sulfate
Animal sources
Animal sourced materials include both animal manures and residues from the slaughter of animals.
Manures are derived from milk-producing dairy animals, egg-producing poultry, and animals raised for meat and hide production, or sport and recreation. Manure is an abundant resource with estimations for cattle manure in the US alone reaching two billion tons annually, and one hen has the potential to produce a cubic foot of manure every six months. By adding manure to crops it adds nitrogen, potassium, phosphorus, sulfur, magnes |
https://en.wikipedia.org/wiki/Pappus%20configuration | In geometry, the Pappus configuration is a configuration of nine points and nine lines in the Euclidean plane, with three points per line and three lines through each point.
History and construction
This configuration is named after Pappus of Alexandria. Pappus's hexagon theorem states that every two triples of collinear points and (none of which lie on the intersection of the two lines) can be completed to form a Pappus configuration, by adding the six lines , , , , , and , and their three intersection points , , and . These three points are the intersection points of the "opposite" sides of the hexagon . According to Pappus' theorem, the resulting system of nine points and eight lines always has a ninth line containing the three intersection points , , and , called the Pappus line.
The Pappus configuration can also be derived from two triangles and that are in perspective with each other (the three lines through corresponding pairs of points meet at a single crossing point) in three different ways, together with their three centers of perspectivity , , and . The points of the configuration are the points of the triangles and centers of perspectivity, and the lines of the configuration are the lines through corresponding pairs of points.
Related constructions
The Levi graph of the Pappus configuration is known as the Pappus graph. It is a bipartite symmetric cubic graph with 18 vertices and 27 edges.
The Desargues configuration can also be defined in terms of perspective triangles, and the Reye configuration can be defined analogously from two tetrahedra that are in perspective with each other in four different ways, forming a desmic system of tetrahedra.
For any nonsingular cubic plane curve in the Euclidean plane, three real inflection points of the curve, and a fourth point on the curve, there is a unique way of completing these four points to form a Pappus configuration in such a way that all nine points lie on the curve.
Applications
A variant of |
https://en.wikipedia.org/wiki/Heart%20symbol | The heart symbol is an ideograph used to express the idea of the "heart" in its metaphorical or symbolic sense. Represented by an anatomically inaccurate shape, the heart symbol is often used to represent the center of emotion, including affection and love, especially romantic love. It is sometimes accompanied or superseded by the "wounded heart" symbol, depicted as a heart symbol pierced with an arrow or as a heart symbol "broken" into two or more pieces, indicating lovesickness.
History
Similar shapes from antiquity
Peepal leaves were used in artistic depictions of the Indus Valley civilisation: a heart-shaped pendant originating from there has been discovered and is now exhibited in the National Museum of India. In the 5th–6th century BC, the heart shape was used to represent the heart-shaped fruit of the plant silphium, a plant possibly used as a contraceptive and an aphrodisiac. Silver coins from Cyrene of the 5th–6th century BC bear a similar design, sometimes accompanied by a silphium plant and is understood to represent its seed or fruit.
Since ancient times in Japan, the heart symbol has been called Inome (猪目), meaning the eye of a wild boar, and it has the meaning of warding off evil spirits. The decorations are used to decorate Shinto shrines, Buddhist temples, castles, and weapons. The oldest examples of this pattern are seen in some of the Japanese original tsuba (sword guard) of the style called toran gata tsuba (lit., inverted egg shaped tsuba) that were attached to swords from the sixth to seventh centuries, and part of the tsuba was hollowed out in the shape of a heart symbol.
Earliest use
The combination of the heart shape and its use within the heart metaphor was developed in the end of the Middle Ages, although the shape has been used in many ancient epigraphy monuments and texts. With possible early examples or direct predecessors in the 13th to 14th century, the familiar symbol of the heart representing love developed in the 15th century, |
https://en.wikipedia.org/wiki/Monopole%20%28mathematics%29 | In mathematics, a monopole is a connection over a principal bundle G with a section of the associated adjoint bundle.
Physical interpretation
Physically, the section can be interpreted as a Higgs field, where the connection and Higgs field should satisfy the Bogomolny equations and be of finite action.
See also
Nahm equations
Instanton
Magnetic monopole
Yang–Mills theory |
https://en.wikipedia.org/wiki/Gellan%20gum | Gellan gum is a water-soluble anionic polysaccharide produced by the bacterium Sphingomonas elodea (formerly Pseudomonas elodea based on the taxonomic classification at the time of its discovery). The gellan-producing bacterium was discovered and isolated by the former Kelco Division of Merck & Company, Inc. in 1978 from the lily plant tissue from a natural pond in Pennsylvania. It was initially identified as a gelling agent to replace agar at significantly lower concentrations in solid culture media for the growth of various microorganisms. Its initial commercial product with the trademark as Gelrite gellan gum, was subsequently identified as a suitable agar substitute as gelling agent in various clinical bacteriological media.
Chemical structure
The repeating unit of the polymer is a tetrasaccharide, which consists of two residues of D-glucose and one of each residues of L-rhamnose and D-glucuronic acid. The tetrasaccharide repeat has the following structure:[D-Glc(β1→4)D-GlcA(β1→4)D-Glc(β1→4)L-Rha(α1→3)]n
Gellan gum products are generally put into two categories, low acyl and high acyl depending on number of acetate groups attached to the polymer. The low acyl gellan gum products form firm, non-elastic, brittle gels, whereas the high acyl gellan gum forms soft and elastic gels.
Microbiological gelling agent
Gellan gum is initially used as a gelling agent, alternative to agar, in microbiological culture. It is able to withstand 120 °C heat. It was identified as an especially useful gelling agent in culturing thermophilic microorganisms. One needs only approximately half the concentration of gellan gum as agar to reach an equivalent gel strength, though the exact texture and quality depends on the concentration of the divalent cations present.
Gellan gum is also used as gelling agent in plant cell culture on Petri dishes, as it provides a very clear gel, facilitating light microscopical analyses of the cells and tissues. Although advertised as being inert, expe |
https://en.wikipedia.org/wiki/Differential%20graded%20algebra | In mathematics, in particular in homological algebra, a differential graded algebra is a graded associative algebra with an added chain complex structure that respects the algebra structure.
Definition
A differential graded algebra (or DG-algebra for short) A is a graded algebra equipped with a map which has either degree 1 (cochain complex convention) or degree −1 (chain complex convention) that satisfies two conditions:
A more succinct way to state the same definition is to say that a DG-algebra is a monoid object in the monoidal category of chain complexes.
A DG morphism between DG-algebras is a graded algebra homomorphism which respects the differential d.
A differential graded augmented algebra (also called a DGA-algebra,
an augmented DG-algebra or simply a DGA) is a DG-algebra equipped with a DG morphism to the ground ring (the terminology is due to Henri Cartan).
Warning: some sources use the term DGA for a DG-algebra.
Examples of DG-algebras
Tensor algebra
The tensor algebra is a DG-algebra with differential similar to that of the Koszul complex. For a vector space over a field there is a graded vector space defined as
where .
If is a basis for there is a differential on the tensor algebra defined component-wise
sending basis elements to
In particular we have and so
Koszul complex
One of the foundational examples of a differential graded algebra, widely used in commutative algebra and algebraic geometry, is the Koszul complex. This is because of its wide array of applications, including constructing flat resolutions of complete intersections, and from a derived perspective, they give the derived algebra representing a derived critical locus.
De-Rham algebra
Differential forms on a manifold, together with the exterior derivation and the exterior product form a DG-algebra. These have wide applications, including in derived deformation theory. See also de Rham cohomology.
Singular cohomology
The singular cohomology of a topological s |
https://en.wikipedia.org/wiki/Milnacipran | Milnacipran (trade names Ixel, Savella, Dalcipran, Toledomin) is a serotonin–norepinephrine reuptake inhibitor (SNRI) used in the clinical treatment of fibromyalgia. It is not approved for the clinical treatment of major depressive disorder in the US, but it is in other countries.
Medical uses
Depression
In a pooled analysis of 7 comparative trials with imipramine, milnacipran and imipramine were shown to have comparable efficacy while milnacipran was significantly better tolerated. A pooled analysis of studies comparing milnacipran and SSRIs concluded a superior efficacy for milnacipran with similar tolerability for milnacipran and SSRIs. A more recent meta-analysis of 6 studies involving more than 1,000 patients showed no distinction between milnacipran and SSRIs in efficacy or discontinuation rates, including discontinuation for side effects or lack of efficacy. A meta-analysis of a total of 16 randomized controlled trials with more than 2200 patients concluded that there were no statistically significant differences in efficacy, acceptability and tolerability when comparing milnacipran with other antidepressant agents. However, compared with TCAs, significantly fewer patients taking milnacipran dropped out due to adverse events. As with other antidepressants, 1 to 3 weeks may elapse before significant antidepressant action becomes clinically evident.
Fibromyalgia
During its development for fibromyalgia, milnacipran was evaluated utilizing a composite responder approach. To be considered as a responder for the composite ‘treatment of fibromyalgia’ endpoint, each patient had to show concurrent and clinically meaningful improvements in pain, physical function, and global impression of disease status. A systematic review in 2015 showed moderate relief for a minority of people with fibromyalgia. Milnacipran was associated with increased adverse events when discontinuing use of the drug.
Social anxiety
There is some evidence that milnacipran may be effective for |
https://en.wikipedia.org/wiki/Pourbaix%20diagram | In electrochemistry, and more generally in solution chemistry, a Pourbaix diagram, also known as a potential/pH diagram, EH–pH diagram or a pE/pH diagram, is a plot of possible thermodynamically stable phases (i.e., at chemical equilibrium) of an aqueous electrochemical system. Boundaries (50 %/50 %) between the predominant chemical species (aqueous ions in solution, or solid phases) are represented by lines. As such a Pourbaix diagram can be read much like a standard phase diagram with a different set of axes. Similarly to phase diagrams, they do not allow for reaction rate or kinetic effects. Beside potential and pH, the equilibrium concentrations are also dependent upon, e.g., temperature, pressure, and concentration. Pourbaix diagrams are commonly given at room temperature, atmospheric pressure, and molar concentrations of 10−6 and changing any of these parameters will yield a different diagram.
The diagrams are named after Marcel Pourbaix (1904–1998), the Russian-born Belgian chemist who invented them.
Naming
Pourbaix diagrams are also known as EH-pH diagrams due to the labeling of the two axes.
Diagram
The vertical axis is labeled EH for the voltage potential with respect to the standard hydrogen electrode (SHE) as calculated by the Nernst equation. The "H" stands for hydrogen, although other standards may be used, and they are for room temperature only.
For a reversible redox reaction described by the following chemical equilibrium:
With the corresponding equilibrium constant :
The Nernst equation is:
sometimes formulated as:
or, more simply directly expressed numerically as:
where:
volt is the thermal voltage or the "Nernst slope" at standard temperature
λ = ln(10) ≈ 2.30, so that volt.
The horizontal axis is labeled pH for the −log function of the H+ ion activity.
The lines in the Pourbaix diagram show the equilibrium conditions, that is, where the activities are equal, for the species on each side of that line. O |
https://en.wikipedia.org/wiki/Point%20of%20interface | In telecommunications a point of interface (POI) is used to show the physical interface between two different carriers, such as a local exchange carrier (LEC) and a wireless carrier, or an LEC and an IntereXchange Carrier (IXC). This demarcation point often defines responsibility as well as serving as a point for testing. In many cases, a POI exists as a point of demarcation ("DEMARC") within an LEC building, and is established under "co-location" agreements. A long distance, wireless, or competitive local carrier "rents" space at the local telephone (usually tandem switch) location.
This space is physically a "cage" in which a device for interconnecting telecom services is installed. This device was originally a wire frame with one side being accessed by the LEC, and the other side accessed by the other carrier. In recent years, "electronic frames" such as digital cross connect systems have been used as POI devices. Local exchange services are ordered from the local telephone carrier who delivers the service to their side of the POI. The other carrier then arranges to its own facilities (fiber, or other type of transport) into the POI and transports the service to its own network facilities.
See also
Federal Standard 1037C
Local loop |
https://en.wikipedia.org/wiki/Bio-Rad%20Laboratories | Bio-Rad Laboratories, Inc. is an American developer and manufacturer of specialized technological products for the life science research and clinical diagnostics markets. The company was founded in 1952 in Berkeley, California, by husband and wife team David and Alice Schwartz, both graduates of the University of California, Berkeley. Bio-Rad is based in Hercules, California, and has operations worldwide.
Business segments
Bio-Rad’s life science products primarily include instruments, software, consumables, reagents, and content for the areas of cell biology, gene expression, protein purification, protein quantitation, drug discovery and manufacture, food safety, and science education. These products are based on technologies to separate, purify, identify, analyze, and amplify biological materials such as antibodies, proteins, nucleic acids, cells, and bacteria.
Bio-Rad’s diagnostic products and systems use a range of technologies and provide clinical information in the blood transfusion, diabetes monitoring, autoimmune, and infectious disease testing markets. These products are used to support the diagnosis, monitoring, and treatment of diseases and other medical conditions.
History
Bio-Rad Laboratories was founded in 1952 by David Schwartz and his wife Alice, both recent graduates of the University of California, Berkeley. In 1976, Bio-Rad acquired Environmental Chemical Specialties (ECS), a producer of human control serum.
In 2008, Bio-Rad were notable for being the opening bell ringers at the New York Stock Exchange on 24 October, a date which went down in financial history as 'Bloody Friday', which saw many of the world's stock exchanges experience the worst declines in their history, with drops of around 10% in most indices.
In 2011, Bio-Rad acquired a new technology, droplet digital PCR. Droplet digital PCR allows scientists to distinguish rare sequences in tumors and precisely measure copy number variation.
In January 2013, Bio-Rad purchased AbD Ser |
https://en.wikipedia.org/wiki/Neuronal%20galvanotropism | Neuronal galvanotropism is the ability to direct the outgrowth of neuronal processes through the use of an extracellular electric field. This technique has been researched since the late 1920s and has been shown to direct the formation of both axonic and dendritic processes in cell culture. It is only possible to direct outgrowth of in vitro preparations at this point. In vitro preparations involve the use of a culture dish, in which there is a species-specific neuronal growth factor. Neurons are removed from a chosen animal, plated onto the dish and allowed to grow (often kept in incubation). The application of an extracellular electric field shows that the cells will grow processes in a direction that demonstrates the direction of the applied electric field. This could be either in the direction of the cathode or anode, depending on the type of substrate the cells are plated onto.
The mechanism underlying this behavior is thought to involve the effect of the electric field on receptors and membrane proteins on the cell's surface. These charged proteins would experience an electrophoretic force pulling them toward the oppositely charged pole of the electric field. Most of these membrane proteins are negatively charged, but the growth, when observed appears to be directed to the negative pole (cathode). This is a strange behavior that can only be accounted for by electroosmotic effects. Positively charged ions outside the cell experience a force towards the cathode. There is a flux of these ions outside the cell and the shear force of solution movement is thought to pull the neurite in the cathodal direction. Also, the electric field may depolarize the cell near the cathodal side opening voltage-gated calcium channels and allowing calcium ions to enter the cell. Calcium is widely believed to be a factor in neurite outgrowth. This theory has been challenged in a recent paper by scientists at Purdue University. Recent studies also involve differentiating between the |
https://en.wikipedia.org/wiki/USC%20Davis%20School%20of%20Gerontology | The USC Leonard Davis School of Gerontology is one of the seventeen academic divisions of the University of Southern California in Los Angeles, focusing on undergraduate and graduate programs in gerontology.
History
Founded in 1975, the Leonard Davis School is the oldest and largest professional School of Gerontology. The school offered the world’s first Ph.D. in Gerontology, the first joint master’s degree in Gerontology and Business Administration, and the first undergraduate Health Science Track in Gerontology.
Its research and services component is the USC Ethel Percy Andrus Gerontology Center. Research in molecular biology, neuroscience, demography, psychology, sociology and public policy is conducted at the Andrus Gerontology Center, founded in 1964.
The school offered the world's first Ph.D. in Gerontology, the first joint master's degree in Gerontology and Business Administration, and the first undergraduate Health Science Track in Gerontology. The Leonard Davis School also offered the first internet-based educational program to be approved by the Western Association of Schools and Colleges.
Academics
The school offers two undergraduate degrees. The Bachelor of Science in Human Development and Aging has a health science track designed for students who wish to pursue medicine or other health-related fields and a social science track that focuses on human development via the behavioral sciences, designed for students pursuing law, policy, psychology, sociology, and health administration. The Bachelor of Science in Lifespan Health is for students pursuing medicine and health-related fields, and its material focuses on disease prevention, detection, and treatment.
Its graduate programs include five master's degrees and two doctorates. The Master of Science in Gerontology is targeted towards students aiming for professional leadership positions, while the Master of Arts in Gerontology is formal training in gerontology for current professionals. The Master |
https://en.wikipedia.org/wiki/Uniform%20theory%20of%20diffraction | In numerical analysis, the uniform theory of diffraction (UTD) is a high-frequency method for solving electromagnetic scattering problems from electrically small discontinuities or discontinuities in more than one dimension at the same point. UTD is an extension of Joseph Keller's geometrical theory of diffraction (GTD).
The uniform theory of diffraction approximates near field electromagnetic fields as quasi optical and uses knife-edge diffraction to determine diffraction coefficients for each diffracting object-source combination. These coefficients are then used to calculate the field strength and phase for each direction away from the diffracting point.
These fields are then added to the incident fields and reflected fields to obtain a total solution.
See also
Electromagnetic modeling
Biot–Tolstoy–Medwin diffraction model |
https://en.wikipedia.org/wiki/RSA%20Secret-Key%20Challenge | The RSA Secret-Key Challenge was a series of cryptographic contests organised by RSA Laboratories with the intent of helping to demonstrate the relative security of different encryption algorithms. The challenge ran from 28 January 1997 until May 2007.
Contest details
For each contest, RSA had posted on its website a block of ciphertext and the random initialization vector used for encryption. To win, a contestant would have had to break the code by finding the original plaintext and the cryptographic key that will generate the posted ciphertext from the plaintext. The challenge consisted of one DES contest and twelve contests based around the block cipher RC5.
Each of the RC5 contests is named after the variant of the RC5 cipher used. The name RC5-w/r/b indicates that the cipher used w-bit words, r rounds, and a key made up of b bytes. The contests are often referred to by the names of the corresponding distributed.net projects, for example RC5-32/12/9 is often known as RC5-72 due to the 72-bit key size.
The first contest was DES Challenge III (and was also part of the DES Challenges) and was completed in 22 hours 15 minutes by distributed.net and the EFF's Deep Crack machine.
In May 2007 RSA Laboratories announced the termination of the challenge, stating that they would not disclose the solutions to the remaining contents, and nor would they confirm or reward prize money for future solutions. On 8 September 2008 distributed.net announced that they would fund a prize of $4000 for the RC5-32/12/9 contest.
Distributed.net
The contests are associated with the distributed.net group, which had actively participated in the challenge by making use of distributed computing to perform a brute force attack.
RC5-32/12/7 was completed on 19 October 1997, with distributed.net finding the winning key in 250 days and winning the US$10,000 prize. The recovered plaintext was: The unknown message is: It's time to move to a longer key length.
RC5-32/12/8 also carried a US$ |
https://en.wikipedia.org/wiki/Self-documenting%20code | In computer programming, self-documenting (or self-describing) source code and user interfaces follow naming conventions and structured programming conventions that enable use of the system without prior specific knowledge. In web development, self-documenting refers to a website that exposes the entire process of its creation through public documentation, and whose public documentation is part of the development process.
Objectives
Commonly stated objectives for self-documenting systems include:
Make source code easier to read and understand
Minimize the effort required to maintain or extend legacy systems
Reduce the need for users and developers of a system to consult secondary documentation sources such as code comments or software manuals
Facilitate automation through self-contained knowledge representation
Conventions
Self-documenting code is ostensibly written using human-readable names, typically consisting of a phrase in a human language which reflects the symbol's meaning, such as article.numberOfWords or TryOpen. The code must also have a clear and clean structure so that a human reader can easily understand the algorithm used.
Practical considerations
There are certain practical considerations that influence whether and how well the objectives for a self-documenting system can be realized.
uniformity of naming conventions
consistency
scope of the application and system requirements
Examples
Below is a very simple example of self-documenting code, using naming conventions in place of explicit comments to make the logic of the code more obvious to human readers.
size_t count_alphabetic_chars(const char *text)
{
if (text == NULL)
return 0;
size_t count = 0;
while (*text != '\0')
{
if (is_alphabetic(*text))
count++;
text++;
}
return count;
}
Criticism
Jef Raskin criticized the belief in "self-documenting" code by saying that code cannot explain the rationale behind why the program |
https://en.wikipedia.org/wiki/Iatrochemistry | Iatrochemistry (; also known as chemiatria or chemical medicine) is a branch of both chemistry and medicine. Having its roots in alchemy, iatrochemistry seeks to provide chemical solutions to diseases and medical ailments.
This area of science has fallen out of use in Europe since the rise of modern establishment medicine. However, iatrochemistry was popular between 1525 and 1660, especially in the Low Countries. Its most notable leader was Paracelsus, an important Swiss alchemist of the 16th century. Iatrochemists believed that physical health was dependent on a specific balance of bodily fluids. Iatrochemical therapies and concepts are still in wide use in South Asia, East Asia and amongst their diasporic communities worldwide.
History in Europe
The preparation of medicines had become a part of alchemy by the early modern period. Around 1350, John of Rupescissa advocated the extraction of the "essence" of both plants and minerals. He often used two relatively new substances during this period: an alcohol distilled from wine and strong mineral acids. Later, "Pseudo-Llull" (i.e. the body of work attributed to, but not necessarily written by, Ramon Llull) picked up and helped in expanding John of Rupescissa's theory.
The most effective and vocal proponent of iatrochemistry was Theophrastus von Hohenheim, also known as Paracelsus (1493–1541). He put his effort into the transmutation of metals and emphasized iatrochemistry in his works. Paracelsus believed that diseases were caused by poisons, but that poisons were not entirely negative. He suggested that poisons, or diseases, could also be cured by poisons; thus, poisons could have beneficial medical effects. Paracelsus's claim led to many chemically prepared medicines in this period which contained toxic components: arsenic, antimony, mercury, lead, and other heavy metals. However, his views were not accepted by many scholars until his writings were organized into systematic form by his followers. Gradually |
https://en.wikipedia.org/wiki/David%20Mitton | David Nelson Godfrey Mitton (27 February 1939 – 16 May 2008) was a British director, producer, writer, model maker and special effects technician. He was best known for producing and directing the children's television programmes Thomas & Friends and TUGS. During the 1960s, he worked with Gerry and Sylvia Anderson as a special effects technician on series such as Thunderbirds, Captain Scarlet and the Mysterons, Joe 90, The Secret Service and UFO.
Early life
Mitton was born on 27 February 1939 in Preston, Prestonpans, East Lothian and educated at The Strathallan School in Perthshire. On leaving school, he briefly attended art school before joining the Royal Air Force. He served with the RAF at Christmas Island, and at Honolulu before returning to serve at Southern Region Air Traffic Control, RAF Uxbridge, later he served at RAF Riyan up-country from Aden in what is now Yemen. He also served in Cyprus with the air-sea rescue service, and then left the Royal Air Force in 1962.
Career
Early career
On his return from RAF service in the early sixties, Mitton embarked on a career in children's television. He began working as a special effects technician on a series of programmes created by Gerry Anderson's AP Films that used a puppet technology called supermarionation. Mitton was a member of the supervising visual effects director Derek Meddings team, displaying a special skill in setting up the electronics necessary to blow up buildings on cue in Thunderbirds (1965–1966), Captain Scarlet and the Mysterons (1967–1968), Joe 90 (1968), The Secret Service (1969) and UFO (1970–1971).
As Gerry Anderson moved away from puppet animation, Mitton became freelance. He worked as assistant director to Ridley Scott on the famous Hovis commercials of the seventies in the United Kingdom and began directing animated television commercials himself. In the mid-seventies, he established a company called Clearwater Films (later Clearwater Features), with former Thunderbirds director Ken T |
https://en.wikipedia.org/wiki/International%20Association%20for%20Cereal%20Science%20and%20Technology | The International Association for Cereal Science and Technology (ICC) was founded in 1955 and was originally called the International Association for Cereal Chemistry. It was set up to develop international standard testing procedures for cereals and flour. It has currently more than fifty member countries and headquarters in Vienna, Austria.
External links
ICC home page
List of ICC standard methods
Standards organisations in Austria
Food technology organizations
1955 establishments in Austria
Cereals
Chemistry organizations |
https://en.wikipedia.org/wiki/Rheometry | Rheometry () generically refers to the experimental techniques used to determine the rheological properties of materials, that is the qualitative and quantitative relationships between stresses and strains and their derivatives. The techniques used are experimental. Rheometry investigates materials in relatively simple flows like steady shear flow, small amplitude oscillatory shear, and extensional flow.
The choice of the adequate experimental technique depends on the rheological property which has to be determined. This can be the steady shear viscosity, the linear viscoelastic properties (complex viscosity respectively elastic modulus), the elongational properties, etc.
For all real materials, the measured property will be a function of the flow conditions during which it is being measured (shear rate, frequency, etc.) even if for some materials this dependence is vanishingly low under given conditions (see Newtonian fluids).
Rheometry is a specific concern for smart fluids such as electrorheological fluids and magnetorheological fluids, as it is the primary method to quantify the useful properties of these materials.
Rheometry is considered useful in the fields of quality control, process control, and industrial process modelling, among others. For some, the techniques, particularly the qualitative rheological trends, can yield the classification of materials based on the main interactions between different possible elementary components and how they qualitatively affect the rheological behavior of the materials. Novel applications of these concepts include measuring cell mechanics in thin layers, especially in drug screening contexts.
Of non-Newtonian fluids
The viscosity of a non-Newtonian fluid is defined by a power law:
where η is the viscosity after shear is applied, η0 is the initial viscosity, γ is the shear rate, and if
, the fluid is shear thinning,
, the fluid is shear thickening,
, the fluid is Newtonian.
In rheometry, shear forces are applied t |
https://en.wikipedia.org/wiki/All-or-nothing%20transform | In cryptography, an all-or-nothing transform (AONT), also known as an all-or-nothing protocol, is an encryption mode which allows the data to be understood only if all of it is known. AONTs are not encryption, but frequently make use of symmetric ciphers and may be applied before encryption. In exact terms, "an AONT is an unkeyed, invertible, randomized transformation, with the property that it is hard to invert unless all of the output is known."
Algorithms
The original AONT, the package transform, was described by Ronald L. Rivest in his 1997 paper "All-Or-Nothing Encryption and The Package Transform". The transform that Rivest proposed involved preprocessing the plaintext by XORing each plaintext block with that block's index encrypted by a randomly chosen key, then appending one extra block computed by XORing that random key and the hashes of all the preprocessed blocks. The result of this preprocessing is called the pseudomessage, and it serves as the input to the encryption algorithm. Undoing the package transform requires hashing every block of the pseudomessage except the last, XORing all the hashes with the last block to recover the random key, and then using the random key to convert each preprocessed block back into its original plaintext block. In this way, it's impossible to recover the original plaintext without first having access to every single block of the pseudomessage.
Although Rivest's paper only gave a detailed description of the package transform as it applies to CBC mode, it can be implemented using a cipher in any mode. Therefore, there are multiple variants: the package ECB transform, package CBC transform, etc.
In 1999 Victor Boyko proposed another AONT, provably secure under the random oracle model.
Apparently at about the same time, D. R. Stinson proposed a different implementation of AONT, without any cryptographic assumptions. This implementation is a linear transform, perhaps highlighting some security weakness of the original de |
https://en.wikipedia.org/wiki/Salesforce | Salesforce, Inc. is an American cloud-based software company headquartered in San Francisco, California. It provides customer relationship management (CRM) software and applications focused on sales, customer service, marketing automation, e-commerce, analytics, and application development.
Founded by former Oracle executive Marc Benioff in February 1999, Salesforce grew quickly, making its IPO in 2004. As of September 2022, Salesforce is the 61st largest company in the world by market cap with a value of nearly US$153 billion. Salesforce's rapid growth made it the first cloud computing company to reach US$1billion in annual revenue, which it achieved in fiscal year 2009. It became the world's largest enterprise software firm in 2022. Salesforce ranked 136th on the most recent edition of the Fortune 500, making US$26.5billion in 2022. Since 2020, Salesforce has also been a component of the Dow Jones Industrial Average.
History
Salesforce was founded in 1999 by former Oracle executive Marc Benioff, together with Parker Harris, Dave Moellenhoff, and Frank Dominguez as a software as a service (SaaS) company. Two of Salesforce's earliest investors were Larry Ellison, the co-founder and first CEO of Oracle, and Halsey Minor, the founder of CNET.
Salesforce was severely affected by the dot-com bubble bursting at the beginning of the new millennium, with the company laying off 20% of its workforce. Despite its losses, Salesforce continued strong during the early 2000s. Salesforce also gained notability during this period for its "the end of software" tagline and marketing campaign, in which it also hired actors to hold up signs with its slogan outside a Siebel Systems conference. Salesforce's revenue continued to increase from 2000 to 2003, with 2003's revenue skyrocketing from $5.4 million in the fiscal year 2001 to over $100 million by December 2003.
Also in 2003, Salesforce held its first annual Dreamforce conference in San Francisco. In June 2004, the company had |
https://en.wikipedia.org/wiki/Autoreceptor | An autoreceptor is a type of receptor located in the membranes of nerve cells. It serves as part of a negative feedback loop in signal transduction. It is only sensitive to the neurotransmitters or hormones released by the neuron on which the autoreceptor sits. Similarly, a heteroreceptor is sensitive to neurotransmitters and hormones that are not released by the cell on which it sits. A given receptor can act as either an autoreceptor or a heteroreceptor, depending upon the type of transmitter released by the cell on which it is embedded.
Autoreceptors may be located in any part of the cell membrane: in the dendrites, the cell body, the axon, or the axon terminals.
Canonically, a presynaptic neuron releases a neurotransmitter across a synaptic cleft to be detected by the receptors on a postsynaptic neuron. Autoreceptors on the presynaptic neuron will also detect this neurotransmitter and often function to control internal cell processes, typically inhibiting further release or synthesis of the neurotransmitter. Thus, release of neurotransmitter is regulated by negative feedback. Autoreceptors are usually G protein-coupled receptors (rather than transmitter-gated ion channels) and act via a second messenger.
Examples
As an example, norepinephrine released from sympathetic neurons may interact with the alpha-2A and alpha-2C adrenoreceptors to inhibit further release of norepinephrine. Similarly, acetylcholine released from parasympathetic neurons may interact with M2 and M4 receptors to inhibit further release of acetylcholine. An atypical example is given by the β-adrenergic autoreceptor in the sympathetic peripheral nervous system, which acts to increase transmitter release.
The D2sh autoreceptor has been shown recently to interact with the trace amine-assorted receptor 1 (TAAR1), a G-Coupled Protein Receptor GPCR, to regulate monoaminergic systems in the brain. Active TAAR1 opposes the autoreceptor's activity by inactivating the dopamine transporter (DAT). I |
https://en.wikipedia.org/wiki/Mobile%20malware | Mobile malware is malicious software that targets mobile phones or wireless-enabled Personal digital assistants (PDA), by causing the collapse of the system and loss or leakage of confidential information. As wireless phones and PDA networks have become more and more common and have grown in complexity, it has become increasingly difficult to ensure their safety and security against electronic attacks in the form of viruses or other malware.
History
The first known virus that affected mobiles, "Timofonica", originated in Spain and was identified by antivirus labs in Russia and Finland in June 2000. "Timofonica" sent SMS messages to GSM-capable mobile phones that read (in Spanish) "Information for you: Telefónica is fooling you." These messages were sent through the Internet SMS gateway of the MoviStar mobile operator. "Timofonica" ran on PCs and did not run on mobile devices so was not a true mobile malware
In June 2004, it was discovered that a company called Ojam had engineered an anti-piracy Trojan hack in older versions of its mobile phone game, Mosquito. This sent SMS texts to the company without the user's knowledge.
In July 2004, computer hobbyists released a proof-of-concept virus Cabir, that infects mobile phones running the Symbian operating system, spreading via Bluetooth wireless. This was the first true mobile malware
In March 2005, it was reported that a computer worm called Commwarrior-A had been infecting Symbian series 60 mobile phones. This specific worm replicated itself through the phone's Multimedia Messaging Service (MMS), sending copies to contacts listed in the phone user's address book.
In August 2010, Kaspersky Lab reported the trojan Trojan-SMS.AndroidOS.FakePlayer.a. This was the first SMS malware that affected Google's Android operating system, and which sent SMS messages to premium rate numbers without the owner's knowledge, accumulating huge bills.
Currently, various antivirus software companies offer mobile antivirus software pr |
https://en.wikipedia.org/wiki/Color%20of%20water | The color of water varies with the ambient conditions in which that water is present. While relatively small quantities of water appear to be colorless, pure water has a slight blue color that becomes deeper as the thickness of the observed sample increases. The hue of water is an intrinsic property and is caused by selective absorption and scattering of blue light. Dissolved elements or suspended impurities may give water a different color.
Intrinsic color
The intrinsic color of liquid water may be demonstrated by looking at a white light source through a long pipe that is filled with purified water and closed at both ends with a transparent window. The light cyan color is caused by weak absorption in the red part of the visible spectrum.
Absorptions in the visible spectrum are usually attributed to excitations of electronic energy states in matter. Water is a simple three-atom molecule, H2O, and all its electronic absorptions occur in the ultraviolet region of the electromagnetic spectrum and are therefore not responsible for the color of water in the visible region of the spectrum. The water molecule has three fundamental modes of vibration. Two stretching vibrations of the O–H bonds in the gaseous state of water occur at = 3650 cm and = 3755 cm−1. Absorption due to these vibrations occurs in the infrared region of the spectrum. The absorption in the visible spectrum is due mainly to the harmonic = 14,318 cm, which is equivalent to a wavelength of 698 nm. In liquid state at 20°C these vibrations are red-shifted by hydrogen bonding, resulting in red absorption at 740 nm, other harmonics such as giving red absorption at 660 nm. The absorption curve for heavy water (DO) is of a similar shape, but is shifted further towards the infrared end of the spectrum, because the vibrational transitions have a lower energy. For this reason, heavy water does not absorb red light and thus large bodies of DO would lack the characteristic cyan color of the more commonly fou |
https://en.wikipedia.org/wiki/Peres%E2%80%93Horodecki%20criterion | The Peres–Horodecki criterion is a necessary condition, for the joint density matrix of two quantum mechanical systems and , to be separable. It is also called the PPT criterion, for positive partial transpose. In the 2×2 and 2×3 dimensional cases the condition is also sufficient. It is used to decide the separability of mixed states, where the Schmidt decomposition does not apply. The theorem was discovered in 1996 by Asher Peres and the Horodecki family (Michał, Paweł, and Ryszard)
In higher dimensions, the test is inconclusive, and one should supplement it with more advanced tests, such as those based on entanglement witnesses.
Definition
If we have a general state which acts on
Its partial transpose (with respect to the B party) is defined as
Note that the partial in the name implies that only part of the state is transposed. More precisely, is the identity map applied to the A party and the transposition map applied to the B party.
This definition can be seen more clearly if we write the state as a block matrix:
Where , and each block is a square matrix of dimension . Then the partial transpose is
The criterion states that if is separable then all the eigenvalues of are non-negative. In other words, if has a negative eigenvalue, is guaranteed to be entangled. The converse of these statements is true if and only if the dimension of the product space is or .
The result is independent of the party that was transposed, because .
Example
Consider this 2-qubit family of Werner states:
It can be regarded as the convex combination of , a maximally entangled state,
and the identity element, a maximally mixed state.
Its density matrix is
and the partial transpose
Its least eigenvalue is . Therefore, the state is entangled for .
Demonstration
If ρ is separable, it can be written as
In this case, the effect of the partial transposition is trivial:
As the transposition map preserves eigenvalues, the spectrum of is the same as the spectrum of , |
https://en.wikipedia.org/wiki/Ice%20pack | An ice pack or gel pack is a portable bag filled with water, refrigerant gel, or liquid, meant to provide cooling. They can be divided into the reusable type, which works as a thermal mass and requires freezing, or the instant type, which cools itself down using chemicals but can only be used once. The instant type is generally limited to medical use as a cold compress to alleviate the pain of minor injuries, while the reusable type is both used as a cold compress and to keep food cool in portable coolers or in insulated shipping containers to keep products cool during transport.
Reusable packs
To be prepared for use, the pack is first placed in a freezer. Both ice and other non-toxic refrigerants (mostly water) can absorb a considerable amount of heat before they warm above .`
Ice packs are used in coolers to keep perishable foods (especially meats, dairy products, eggs, etc.) below the danger zone when outside a refrigerator or freezer, and to keep drinks pleasantly cool. The amount of ice needed varies with the amount of food, its initial temperature, the thermal insulation of the cooler, and the ambient temperature and exposure to direct sunlight. Ice initially well below freezing temperature will last a little longer.
Water has a much higher latent heat of fusion than most substances, and a melting temperature which is convenient and easily attained with, for example, a household freezer. Additives to improve the properties of water are often used. For example, substances can be added to prevent bacterial growth in the pack, or to prevent the water from solidifying so it remains a thick gel throughout use.
Gel packs are often made of non-toxic materials that will remain a slow-flowing gel, and therefore will not spill easily or cause contamination if the container breaks. Gel packs may be made by adding hydroxyethyl cellulose, sodium polyacrylate,Super absorbent polymerSAP or vinyl-coated silica gel.
Hot-or-cold packs
Hot-or-cold packs are ice packs tha |
https://en.wikipedia.org/wiki/Isotopomer | Isotopomers or isotopic isomers are isomers which differ by isotopic substitution, and which have the same number of atoms of each isotope but in a different arrangement. For example, CH3OD and CH2DOH are two isotopomers of monodeuterated methanol.
The molecules may be either structural isomers (constitutional isomers) or stereoisomers depending on the location of the isotopes. Isotopomers have applications in areas including nuclear magnetic resonance spectroscopy, reaction kinetics, and biochemistry.
Description
Isotopomers or isotopic isomers are isomers with isotopic atoms, having the same number of each isotope of each element but differing in their positions in the molecule. The result is that the molecules are either constitutional isomers or stereoisomers solely based on isotopic location. The term isotopomer was first proposed by Seeman and Paine in 1992 to distinguish isotopic isomers from isotopologues (isotopic homologues).
Examples
CH3CHDCH3 and CH3CH2CH2D are a pair of structural isotopomers of propane.
(R)- and (S)-CH3CHDOH are isotopic stereoisomers of ethanol.
(Z)- and (E)-CH3CH=CHD are examples of isotopic stereoisomers of propene.
Use
13C-NMR
In nuclear magnetic resonance spectroscopy, the highly abundant 12C isotope does not produce any signal whereas the comparably rare 13C isotope is easily detected. As a result, carbon isotopomers of a compound can be studied by carbon-13 NMR to learn about the different carbon atoms in the structure. Each individual structure that contains a single 13C isotope provides data about the structure in its immediate vicinity. A large sample of a chemical contains a mixture of all such isotopomers, so a single spectrum of the sample contains data about all carbons in it. Nearly all of the carbon in normal samples of carbon-based chemicals is 12C, with only about 1% abundance of 13C, so there is only about a 1% abundance of the total of the singly-substituted isotopologues, and exponentially smaller amoun |
https://en.wikipedia.org/wiki/Medoid | Medoids are representative objects of a data set or a cluster within a data set whose sum of dissimilarities to all the objects in the cluster is minimal. Medoids are similar in concept to means or centroids, but medoids are always restricted to be members of the data set. Medoids are most commonly used on data when a mean or centroid cannot be defined, such as graphs. They are also used in contexts where the centroid is not representative of the dataset like in images, 3-D trajectories and gene expression (where while the data is sparse the medoid need not be). These are also of interest while wanting to find a representative using some distance other than squared euclidean distance (for instance in movie-ratings).
For some data sets there may be more than one medoid, as with medians.
A common application of the medoid is the k-medoids clustering algorithm, which is similar to the k-means algorithm but works when a mean or centroid is not definable. This algorithm basically works as follows. First, a set of medoids is chosen at random. Second, the distances to the other points are computed. Third, data are clustered according to the medoid they are most similar to. Fourth, the medoid set is optimized via an iterative process.
Note that a medoid is not equivalent to a median, a geometric median, or centroid. A median is only defined on 1-dimensional data, and it only minimizes dissimilarity to other points for metrics induced by a norm (such as the Manhattan distance or Euclidean distance). A geometric median is defined in any dimension, but unlike a medoid, it is not necessarily a point from within the original dataset.
Definition
Let be a set of points in a space with a distance function d. Medoid is defined as
Clustering with medoids
Medoids are a popular replacement for the cluster mean when the distance function is not (squared) Euclidean distance, or not even a metric (as the medoid does not require the triangle inequality). When partitioning the d |
https://en.wikipedia.org/wiki/Identical%20ancestors%20point | In genetic genealogy, the identical ancestors point (IAP), or all common ancestors (ACA) point, or genetic isopoint, is the most recent point in a given population's past such that each individual alive at this point either has no living descendants, or is the ancestor of every individual alive in the present. This point lies further in the past than the population's most recent common ancestor (MRCA).
Calculation
A set of full siblings has an IAP one generation back: their parents. Similarly, double first cousins have an IAP two generations back: the four grandparents.
Considering all humans alive today and moving back in time, we eventually arrive at the MRCA to all humans. The MRCA had many contemporary companions. Many of these contemporaries had descendant lines to some people living today, but not to all people living today. Others did not have any children, or had descendants, but all descendant lines are now fully extinct.
Going further back, all the ancestors of the MRCA are also common ancestors to all humans, just not the most recent. As we move further back in time, other common ancestors will be found on other lines, resulting in more and more of the ancient population being common ancestors. Eventually the point is reached where all people in the past population fall into one of two categories: they are common ancestors, with at least one line of descent to everyone living today, or they are the ancestors of no one alive today, because their lines of descent are completely extinct on every branch. This point in time is termed the 'identical ancestors point'.
Joseph T. Chang has proposed that in a large, well mixed population of size , we only have to go generations in the past to find the time when everyone in the population (who left descendants) is an ancestor to the entire population. For example, a population of 4,000 individuals would, on average, have a most recent common ancestor about 13 generations earlier and an IAP about 24 or 25 gene |
https://en.wikipedia.org/wiki/Isotropic%20radiator | An isotropic radiator is a theoretical point source of electromagnetic or sound waves which radiates the same intensity of radiation in all directions. It has no preferred direction of radiation. It radiates uniformly in all directions over a sphere centred on the source. Isotropic radiators are used as reference radiators with which other sources are compared, for example in determining the gain of antennas. A coherent isotropic radiator of electromagnetic waves is theoretically impossible, but incoherent radiators can be built. An isotropic sound radiator is possible because sound is a longitudinal wave.
The unrelated term isotropic radiation refers to radiation which has the same intensity in all directions, thus an isotropic radiator does not produce isotropic radiation.
Physics
In physics, an isotropic radiator is a point radiation or sound source. At a distance, the Sun is an isotropic radiator of electromagnetic radiation.
Antenna theory
In antenna theory, an isotropic antenna is a hypothetical antenna radiating the same intensity of radio waves in all directions. It thus is said to have a directivity of 0 dBi (dB relative to isotropic) in all directions. Since it is entirely non-directional, it serves as a hypothetical worst-case against which directional antennas may be compared.
In reality, a coherent isotropic radiator of linear polarization can be shown to be impossible.
Its radiation field could not be consistent with the Helmholtz wave equation (derived from Maxwell's equations) in all directions simultaneously. Consider a large sphere surrounding the hypothetical point source, in the far field of the radiation pattern so that at that radius the wave over a reasonable area is essentially planar. In the far field the electric (and magnetic) field of a plane wave in free space is always perpendicular to the direction of propagation of the wave. So the electric field would have to be tangent to the surface of the sphere everywhere, and contin |
https://en.wikipedia.org/wiki/Transcription%20%28music%29 | In music, transcription is the practice of notating a piece or a sound which was previously unnotated and/or unpopular as a written music, for example, a jazz improvisation or a video game soundtrack. When a musician is tasked with creating sheet music from a recording and they write down the notes that make up the piece in music notation, it is said that they created a musical transcription of that recording. Transcription may also mean rewriting a piece of music, either solo or ensemble, for another instrument or other instruments than which it was originally intended. The Beethoven Symphonies transcribed for solo piano by Franz Liszt are an example. Transcription in this sense is sometimes called arrangement, although strictly speaking transcriptions are faithful adaptations, whereas arrangements change significant aspects of the original piece.
Further examples of music transcription include ethnomusicological notation of oral traditions of folk music, such as Béla Bartók's and Ralph Vaughan Williams' collections of the national folk music of Hungary and England respectively. The French composer Olivier Messiaen transcribed birdsong in the wild, and incorporated it into many of his compositions, for example his Catalogue d'oiseaux for solo piano. Transcription of this nature involves scale degree recognition and harmonic analysis, both of which the transcriber will need relative or perfect pitch to perform.
In popular music and rock, there are two forms of transcription. Individual performers copy a note-for-note guitar solo or other melodic line. As well, music publishers transcribe entire recordings of guitar solos and bass lines and sell the sheet music in bound books. Music publishers also publish PVG (piano/vocal/guitar) transcriptions of popular music, where the melody line is transcribed, and then the accompaniment on the recording is arranged as a piano part. The guitar aspect of the PVG label is achieved through guitar chords written above the melody |
https://en.wikipedia.org/wiki/Corrado%20Segre | Corrado Segre (20 August 1863 – 18 May 1924) was an Italian mathematician who is remembered today as a major contributor to the early development of algebraic geometry.
Early life
Corrado's parents were Abramo Segre and Estella De Benedetti.
Career
Segre developed his entire career at the University of Turin, first as a student of Enrico D'Ovidio. In 1883 he published a dissertation on quadrics in projective space and was named an assistant to professors in algebra and analytic geometry. In 1885 he also assisted in descriptive geometry. He began to instruct in projective geometry, as a stand-in for Giuseppe Bruno, from 1885 to 1888. Then for 36 years, he had the chair in higher geometry following D'Ovidio. Segre and Giuseppe Peano made Turin known in geometry, and their complementary instruction has been noted as follows:
The Erlangen program of Felix Klein appealed early on to Segre, and he became a promulgator. First, in 1885 he published an article on conics in the plane where he demonstrated how group theory facilitated the study. As Hawkins says (page 252) "the totality of all conics in the plane is identified with P5(C)". The group of its projectivities is then the group that permutes conics. About Segre, Hawkins writes
The inspiring Geometrie der Lage (1847) of Karl Georg Christian von Staudt provided Segre with another project. He encouraged Mario Pieri to make a translation, Geometria di Posizione (1889), while Segre composed a biographical sketch of von Staudt that was included in the publication.
Segre also expanded algebraic geometry by consideration of multicomplex numbers, in particular the bicomplex numbers. Segre's 1892 contribution to Mathematische Annalen shows him extending the work of William Rowan Hamilton and William Kingdon Clifford on biquaternions. But Segre was unaware of an earlier study of tessarines that had anticipated his bicomplex numbers.
In English, the best-known work of Segre is an inspirational essay meant for Italian stu |
https://en.wikipedia.org/wiki/Slipped%20capital%20femoral%20epiphysis | Slipped capital femoral epiphysis (SCFE or skiffy, slipped upper femoral epiphysis, SUFE or , coxa vara adolescentium) is a medical term referring to a fracture through the growth plate (physis), which results in slippage of the overlying end of the femur (metaphysis).
Normally, the head of the femur, called the capital, should sit squarely on the femoral neck. Abnormal movement along the growth plate results in the slip. The term slipped capital femoral epiphysis is actually a misnomer, because the epiphysis (end part of a bone) remains in its normal anatomical position in the acetabulum (hip socket) due to the ligamentum teres femoris. It is actually the metaphysis (neck part of a bone) which slips in an anterior direction with external rotation.
SCFE is the most common hip disorder in adolescence. SCFEs usually cause groin pain on the affected side, but sometimes cause knee or thigh pain. One in five cases involves both hips, resulting in pain on both sides of the body. SCFEs occurs slightly more commonly in adolescent males, especially young black males, although it also affects females. Whilst it can occur in any child, the major risk factor is childhood obesity. Symptoms include the gradual, progressive onset of thigh or knee pain with a painful limp. Hip motion will be limited, particularly internal rotation. Running, and other strenuous activity on legs, will also cause the hips to abnormally move due to the condition and can potentially worsen the pain. Stretching is very limited.
Signs and symptoms
Usually, a SCFE causes groin pain, but it may cause pain in only the thigh or knee, because the pain may be referred along the distribution of the obturator nerve. The pain may occur on both sides of the body (bilaterally), as up to 40 percent of cases involve slippage on both sides. In cases of bilateral SCFEs, they typically occur within one year of each other. About 20 percent of all cases include a SCFE on both sides at the time of presentation.
Signs o |
https://en.wikipedia.org/wiki/Contributors%20to%20the%20mathematical%20background%20for%20general%20relativity | This is a list of contributors to the mathematical background for general relativity. For ease of readability, the contributions (in brackets) are unlinked but can be found in the contributors' article.
B
Luigi Bianchi (Bianchi identities, Bianchi groups, differential geometry)
C
Élie Cartan (curvature computation, early extensions of GTR, Cartan geometries)
Elwin Bruno Christoffel (connections, tensor calculus, Riemannian geometry)
Clarissa-Marie Claudel (Geometry of photon surfaces)
D
Tevian Dray (The Geometry of General Relativity)
E
Luther P. Eisenhart (semi-Riemannian geometries)
Frank B. Estabrook (Wahlquist-Estabrook approach to solving PDEs; see also parent list)
Leonhard Euler (Euler-Lagrange equation, from which the geodesic equation is obtained)
G
Carl Friedrich Gauss (curvature, theory of surfaces, intrinsic vs. extrinsic)
K
Martin Kruskal (inverse scattering transform; see also parent list)
L
Joseph Louis Lagrange (Lagrangian mechanics, Euler-Lagrange equation)
Tullio Levi-Civita (tensor calculus, Riemannian geometry; see also parent list)
André Lichnerowicz (tensor calculus, transformation groups)
M
Alexander Macfarlane (space analysis and Algebra of Physics)
Jerrold E. Marsden (linear stability)
N
Isaac Newton (Newton's identities for characteristic of Einstein tensor)
R
Gregorio Ricci-Curbastro (Ricci tensor, differential geometry)
Georg Bernhard Riemann (Riemannian geometry, Riemann curvature tensor)
S
Richard Schoen (Yamabe problem; see also parent list)
Corrado Segre (Segre classification)
W
Hugo D. Wahlquist (Wahlquist-Estabrook algorithm; see also parent list)
Hermann Weyl (Weyl tensor, gauge theories; see also parent list)
Eugene P. Wigner (stabilizers in Lorentz group)
See also
Contributors to differential geometry
Contributors to general relativity
Physics-related lists |
https://en.wikipedia.org/wiki/JAUS | Joint Architecture for Unmanned Systems (JAUS), formerly known as Joint Architecture for Unmanned Ground Systems (JAUGS), was originally an initiative started in 1998 by the United States Department of Defense to develop an open architecture for the domain of unmanned systems.
In order to ensure that the component architecture is applicable to the entire domain of current and future unmanned systems, it is built on five principles: vehicle platform independence, mission isolation, computer hardware independence, technology independence, and operator use independence.
The JAUS Reference Architecture, which is no longer being maintained, is a component based message passing architecture that defines a data format and methods of communication between computing nodes. The architecture dictates a hierarchical system built up of subsystems, nodes and components, and contains a strictly defined message set to support interoperability. Significant portions of the architecture, including the definitions for subsystem, node and component, have been loosely defined in order to accommodate for the five principles on which it is based.
The architecture has migrated from the JAUS Working Group, which was composed of individuals from the government, industry and academia, to the Society of Automotive Engineers, Aerospace Division, Avionics Systems Division. The AS4, Unmanned Systems Technical Committee now maintains and advances the set of standards. The following standards have been migrated from the JAUS Reference Architecture to a services based framework:
AS5669, JAUS Transport Standard.Defines packet construction addressing transport concerns including header compression, source/destination addressing, TCP, UDP and Serial links. AS5669 defines the format of a JAUS message as it flows between systems in an Ethernet (TCP and UDP) or serial data link.
AS5710, JAUS Core Service Set.Establishes a common set of services for distributed systems communication and coordination. |
https://en.wikipedia.org/wiki/Polony%20%28biology%29 | Polony is a contraction of "polymerase colony," a small colony of DNA.
Polonies are discrete clonal amplifications of a single DNA molecule, grown in a gel matrix. This approach greatly improves the signal-to-noise ratio. Polonies can be generated using several techniques that include solid-phase polymerase chain reaction (PCR) in polyacrylamide gels. However, other earlier patented technologies, such as that from Manteia Predictive Medicine (acquired by Solexa), which generate DNA on a solid-phase surface by bridge amplification, are generally referred to as "clusters".
The terminology and distinction between 'polony' and 'cluster' have become confused recently. Growth of clonal copies of DNA on bead surfaces remains to be generically named although some also seek to name this technique as a "polony" method. The concept of localizing and analyzing regions containing clonal nucleic acid populations was first described in patents by Brown, et al.. (assigned to Genomic Nanosystems), however these are in liquid phase. Clusters are distinct in that they are based on solid-phase amplification of single DNA molecules where the DNA has been covalently attached to a surface. This technology, initially coined "DNA colony generation", had been invented and developed in late 1996 at Glaxo-Welcome's Geneva Biomedical Research Institute (GBRI), by Dr Pascal Mayer and Dr Laurent Farinelli, and was publicly presented for the first time in 1998. It was finally brought to market by Solexa. Solexa Ltd/INC (Bentley et al.). |
https://en.wikipedia.org/wiki/Admissible%20numbering | In computability theory, admissible numberings are enumerations (numberings) of the set of partial computable functions that can be converted to and from the standard numbering. These numberings are also called acceptable numberings and acceptable programming systems.
Rogers' equivalence theorem shows that all acceptable programming systems are equivalent to each other in the formal sense of numbering theory.
Definition
The formalization of computability theory by Kleene led to a particular universal partial computable function Ψ(e, x) defined using the T predicate. This function is universal in the sense that it is partial computable, and for any partial computable function f there is an e such that, for all x, f(x) = Ψ(e,x), where the equality means that either both sides are undefined or both are defined and are equal. It is common to write ψe(x) for Ψ(e,x); thus the sequence ψ0, ψ1, ... is an enumeration of all partial computable functions. Such enumerations are formally called computable numberings of the partial computable functions.
An arbitrary numbering η of partial functions is defined to be an admissible numbering if:
The function H(e,x) = ηe(x) is a partial computable function.
There is a total computable function f such that, for all e, ηe = ψf(e).
There is a total computable function g such that, for all e, ψe = ηg(e).
Here, the first bullet requires the numbering to be computable; the second requires that any index for the numbering η can be converted effectively to an index to the numbering ψ; and the third requires that any index for the numbering ψ can be effectively converted to an index for the numbering η.
Rogers' equivalence theorem
Hartley Rogers, Jr. showed that a numbering η of the partial computable functions is admissible if and only if there is a total computable bijection p such that, for all e, ηe = ψp(e) (Soare 1987:25).
See also
Friedberg numbering |
https://en.wikipedia.org/wiki/Phreatophyte | A phreatophyte is a deep-rooted plant that obtains a significant portion of the water that it needs from the phreatic zone (zone of saturation) or the capillary fringe above the phreatic zone.
Phreatophytes are plants that are supplied with surface water and often have their roots constantly in touch with moisture. A phreatophyte is one that absorbs its water from a constant source on the ground. They can usually be found along streams where there is a steady flow of surface or groundwater in areas where the water table is near the surface.
Phreatophytes live in areas with standing or running water, in arid areas and along the riverbeds and areas, apparently dry, where the water table is very shallow and near the surface. These plants have very deep roots that are able to reach the water table. Phreatophytes are not only characteristic of arid or desert zones, but also of wetlands, floodplains, depressions that hold water and estuaries. In the wetlands, ecological classification does not provide a special classification, since in this case, most of the plants in the regions of high rainfall can deepen their roots to the top of the capillary fringe immediately above the water table, and function well as a phreatophyte. In this case they receive the label of mesophytic. Phreatophytic artificial extensions, manmade, are used as a method to purify greywater.
Biological value
They are plants of great ecological value, fast growing pioneers and highly resistant to disease. They make excellent fodder for livestock and provide nesting areas and shelter for fauna. They are used as fuel, cheap construction material, and basketry. Many of the plants grow in degraded waters, salty or saline, that are useless for agriculture. Phreatophyte plants help to purify these waters and their roots fix heavy metals with a bacterial filter. For example, it is estimated that the total annual groundwater phreatophytes consumed in the western U.S. alone is about .
Phreatophytes are indic |
https://en.wikipedia.org/wiki/Crossmodal | Crossmodal perception or cross-modal perception is perception that involves interactions between two or more different sensory modalities. Examples include synesthesia, sensory substitution and the McGurk effect, in which vision and hearing interact in speech perception.
Crossmodal perception, crossmodal integration and cross modal plasticity of the human brain are increasingly studied in neuroscience to gain a better understanding of the large-scale and long-term properties of the brain. A related research theme is the study of multisensory perception and multisensory integration.
As a cultural movement
Described as synthesizing art, science and entrepreneurship. Crossmodialism as a movement started in London in 2013. The movement focuses on bringing together the talents of traditionally distinct disciplines to make cohesive works. Crossmodalism has been compared to the Dadaist art movement of the 20th century, as well as other avant garde styles like futurism and surrealism.
See also
Crossmodal attention
Ideasthesia
Molyneux's problem
Sensory substitution |
https://en.wikipedia.org/wiki/Bond%20length | In molecular geometry, bond length or bond distance is defined as the average distance between nuclei of two bonded atoms in a molecule. It is a transferable property of a bond between atoms of fixed types, relatively independent of the rest of the molecule.
Explanation
Bond length is related to bond order: when more electrons participate in bond formation the bond is shorter. Bond length is also inversely related to bond strength and the bond dissociation energy: all other factors being equal, a stronger bond will be shorter. In a bond between two identical atoms, half the bond distance is equal to the covalent radius.
Bond lengths are measured in the solid phase by means of X-ray diffraction, or approximated in the gas phase by microwave spectroscopy. A bond between a given pair of atoms may vary between different molecules. For example, the carbon to hydrogen bonds in methane are different from those in methyl chloride. It is however possible to make generalizations when the general structure is the same.
Bond lengths of carbon with other elements
A table with experimental single bonds for carbon to other elements is given below. Bond lengths are given in picometers. By approximation the bond distance between two different atoms is the sum of the individual covalent radii (these are given in the chemical element articles for each element). As a general trend, bond distances decrease across the row in the periodic table and increase down a group. This trend is identical to that of the atomic radius.
Bond lengths in organic compounds
The bond length between two atoms in a molecule depends not only on the atoms but also on such factors as the orbital hybridization and the electronic and steric nature of the substituents. The carbon–carbon (C–C) bond length in diamond is 154 pm. It is generally considered the average length for a carbon–carbon single bond, but is also the largest bond length that exists for ordinary carbon covalent bonds. Since one atomic unit |
https://en.wikipedia.org/wiki/Jean-Luc%20Margot | Jean-Luc Margot (born 1969) is a Belgian-born astronomer and a UCLA professor with expertise in planetary sciences and SETI.
Career
Margot has discovered and studied several binary asteroids with radar and optical telescopes. His discoveries include (87) Sylvia I Romulus, (22) Kalliope I Linus, S/2003 (379) 1, (702) Alauda I Pichi üñëm, and the binary nature of (69230) Hermes.
In 2000, he obtained the first images of binary near-Earth asteroids and described formation of the binary by a spin-up process. Margot and his research group have studied the influence of sunlight on the orbits and spins of asteroids, the Yarkovsky and YORP effects.
In 2007, Margot and collaborators determined that Mercury has a molten core from the analysis of small variations in the rotation rate of the planet. These observations also enabled a measurement of the size of the core based on a concept proposed by Stan Peale.
In 2012, Margot and graduate student Julia Fang analyzed Kepler space telescope data to infer the architecture of planetary systems. They described planetary systems as "flatter than pancakes." They also showed that many planetary systems are dynamically packed.
Margot proposed an extension to the IAU definition of planet that applies to exoplanets.
Between 2006 and 2021, Margot and collaborators measured the spin of Venus with a radar speckle tracking technique. They measured the orientation and precession of the spin axis. They also measured the duration of the length of day and the amplitude of length-of-day variations, which they attribute to transfer of momentum between the atmosphere and the solid planet.
Since 2016, he has conducted searches for technosignatures using large radio telescopes with UCLA students. Volunteers can contribute to SETI through the "Are we alone in the universe?" citizen science collaboration.
Honors and awards
Margot was awarded the H. C. Urey Prize by the American Astronomical Society in 2004. The asteroid 9531 Jean-Luc is name |
https://en.wikipedia.org/wiki/Clone%20tool | The clone tool, as it is known in Adobe Photoshop, Inkscape, GIMP, and Corel PhotoPaint, is used in digital image editing to replace information for one part of a picture with information from another part. In other image editing software, its equivalent is sometimes called a rubber stamp tool or a clone brush.
Applications
A typical use for the tool is in – more colloquially, "airbrushing" or "photoshopping" out an unwanted part of the image.
If a part of an image is removed simply by cutting it out, then a hole is left in the background. The Clone tool can fill in this hole convincingly with a copy of the existing background from elsewhere in the image.
A common use for this tool is to retouch skin, particularly in portraits, to remove blemishes and make skin tones more even. Cloning can also be used to remove other unwanted elements, such as telephone wires, an unwanted bird in the sky, and the like.
A more automated method of object removal uses texture synthesis to fill in gaps. Of these, patch-based texture synthesis or "image quilting" is essentially an automated application of the clone tool, choosing the optimal source area so as to patch over with a minimal seam.
In some cases, the undesired object is mixed with the remainder of the image, and a simple circular brush, even with feathering, would not work. For these cases, some programs allow an object to be selected by color/outline so other areas are not affected. Other programs allow edge/color sensitive brushes to deal with such objects.
Healing tool
A similar tool is the healing tool, which occurs in variants such as the healing brush or spot healing tool. These incorporate the existing texture, rather than painting it over.
See also
Inpainting
Seam carving |
https://en.wikipedia.org/wiki/Shikimic%20acid | Shikimic acid, more commonly known as its anionic form shikimate, is a cyclohexene, a cyclitol and a cyclohexanecarboxylic acid. It is an important biochemical metabolite in plants and microorganisms. Its name comes from the Japanese flower shikimi (, the Japanese star anise, Illicium anisatum), from which it was first isolated in 1885 by Johan Fredrik Eykman. The elucidation of its structure was made nearly 50 years later.
Biosynthesis
Phosphoenolpyruvate and erythrose-4-phosphate condense to form 3-deoxy-D-arabinoheptulosonate-7-phosphate (DAHP), in a reaction catalyzed by the enzyme DAHP synthase. DAHP is then transformed to 3-dehydroquinate (DHQ), in a reaction catalyzed by DHQ synthase. Although this reaction requires nicotinamide adenine dinucleotide (NAD) as a cofactor, the enzymic mechanism regenerates it, resulting in the net use of no NAD.
DHQ is dehydrated to 3-dehydroshikimic acid by the enzyme 3-dehydroquinate dehydratase, which is reduced to shikimic acid by the enzyme shikimate dehydrogenase, which uses nicotinamide adenine dinucleotide phosphate (NADPH) as a cofactor.
Shikimate pathway
Biosynthesis of the aromatic amino acids
The shikimate pathway is a seven-step metabolic route used by bacteria, fungi, algae, parasites, and plants for the biosynthesis of aromatic amino acids (phenylalanine, tyrosine, and tryptophan). This pathway is not found in animals; therefore, phenylalanine and tryptophan represent essential amino acids that must be obtained from the animal's diet (animals can synthesise tyrosine from phenylalanine, and therefore is not an essential amino acid except for individuals unable to hydroxylate phenylalanine to tyrosine).
The seven enzymes involved in the shikimate pathway are DAHP synthase, 3-dehydroquinate synthase, 3-dehydroquinate dehydratase, shikimate dehydrogenase, shikimate kinase, EPSP synthase, and chorismate synthase. The pathway starts with two substrates, phosphoenol pyruvate and erythrose-4-phosphate and ends with |
https://en.wikipedia.org/wiki/Electrovacuum%20solution | In general relativity, an electrovacuum solution (electrovacuum) is an exact solution of the Einstein field equation in which the only nongravitational mass–energy present is the field energy of an electromagnetic field, which must satisfy the (curved-spacetime) source-free Maxwell equations appropriate to the given geometry. For this reason, electrovacuums are sometimes called (source-free) Einstein–Maxwell solutions.
Definition
In general relativity, the geometric setting for physical phenomena is a Lorentzian manifold, which is interpreted as a curved spacetime, and which is specified by defining a metric tensor (or by defining a frame field). The Riemann curvature tensor of this manifold and associated quantities such as the Einstein tensor , are well-defined. In general relativity, they can be interpreted as geometric manifestations (curvature and forces) of the gravitational field.
We also need to specify an electromagnetic field by defining an electromagnetic field tensor on our Lorentzian manifold. To be classified as an electrovacuum solution, these two tensors are required to satisfy two following conditions
The electromagnetic field tensor must satisfy the source-free curved spacetime Maxwell field equations and
The Einstein tensor must match the electromagnetic stress–energy tensor, .
The first Maxwell equation is satisfied automatically if we define the field tensor in terms of an electromagnetic potential vector . In terms of the dual covector (or potential one-form) and the electromagnetic two-form, we can do this by setting . Then we need only ensure that the divergences vanish (i.e. that the second Maxwell equation is satisfied for a source-free field) and that the electromagnetic stress–energy matches the Einstein tensor.
Invariants
The electromagnetic field tensor is antisymmetric, with only two algebraically independent scalar invariants,
Here, the star is the Hodge star.
Using these, we can classify the possible electromagne |
https://en.wikipedia.org/wiki/Passiflora%20ligularis | Passiflora ligularis, commonly known as the sweet granadilla or grenadia, is a plant species in the genus Passiflora. It is known as granadilla in Bolivia, Colombia, Nicaragua, Costa Rica, Ecuador, Mexico, The Azores, South Africa and Peru; granadilla común in Guatemala; granadilla de China or parcha dulce in Venezuela and granaditta in Jamaica.
Description
The epithet ligularis comes from the plant's ligulate corollae. It is native to the Andes Mountains, mainly Peru, including Bolivia, Costa Rica, Ecuador, Colombia and Venezuela. It grows as far south as northern Argentina and as far north as Mexico. Outside of its native range it grows in the tropical mountains of Africa and Australia (where they are known as passionfruit or Granadilla), and is now common in local markets of Papua New Guinea, where it is known as 'sugar fruit'. It likes climates ranging from and between of annual rain. It lives at altitudes ranging from above sea level. They have abundant, simple leaves and greenish-white flowers. The fruit is orange to yellow colored with small light markings. It has a round shape with a tip ending in the stem. The fruit is between long and between in diameter. The outer shell is hard and slippery, and has soft padding on the interior to protect the seeds. The seeds, which are hard and black, are surrounded by a gelatinous sphere of transparent pulp. The pulp is the edible part of the fruit and has a soft sweet taste. It is very aromatic and contains vitamins A, C, and K, phosphorus, iron, and calcium. The main producers are Peru, Venezuela, Colombia, Ecuador, Brazil (where it is known as or "sweet passion fruit"), South Africa, Rwanda and Kenya. The main importers are the United States, Canada, Belgium, the Netherlands, Switzerland, and Spain.
Passiflora ligularis, is an evergreen climbing shrub, producing stems of up to long. The stems scramble over the ground or clamber into the surrounding vegetation, attaching themselves by means of coiling tendril |
https://en.wikipedia.org/wiki/Tetrameric%20protein | A tetrameric protein is a protein with a quaternary structure of four subunits (tetrameric). Homotetramers have four identical subunits (such as glutathione S-transferase), and heterotetramers are complexes of different subunits. A tetramer can be assembled as dimer of dimers with two homodimer subunits (such as sorbitol dehydrogenase), or two heterodimer subunits (such as hemoglobin).
Subunit interactions in tetramers
The interactions between subunits forming a tetramer is primarily determined by non covalent interaction. Hydrophobic effects, hydrogen bonds and electrostatic interactions are the primary sources for this binding process between subunits. For homotetrameric proteins such as Sorbitol dehydrogenase (SDH), the structure is believed to have evolved going from a monomeric to a dimeric and finally a tetrameric structure in evolution. The binding process in SDH and many other tetrameric enzymes can be described by the gain in free energy which can be determined from the rate of association and dissociation.
The following image shows the assembly of the four subunits (A,B,C and D) in SDH.
Hydrogen bonds between subunits
Hydrogen bonding networks between subunits has been shown to be important for the stability of the tetrameric quaternary protein structure. For example, a study of SDH which used diverse methods such as protein sequence alignments, structural comparisons, energy calculations, gel filtration experiments and enzyme kinetics experiments, could reveal an important hydrogen bonding network which stabilizes the tetrameric quaternary structure in mammalian SDH.
Tetramers in immunology
In immunology, MHC tetramers can be used in tetramer assays, to quantify numbers of antigen-specific T cells (especially CD8+ T cells). MHC tetramers are based on recombinant class I molecules that, through the action of bacterial BirA, have been biotinylated. These molecules are folded with the peptide of interest and β2M and tetramerized by a fluorescently l |
https://en.wikipedia.org/wiki/Redaction | Redaction or sanitization is the process of removing sensitive information from a document so that it may be distributed to a broader audience. It is intended to allow the selective disclosure of information. Typically, the result is a document that is suitable for publication or for dissemination to others rather than the intended audience of the original document.
When the intent is secrecy protection, such as in dealing with classified information, redaction attempts to reduce the document's classification level, possibly yielding an unclassified document. When the intent is privacy protection, it is often called data anonymization. Originally, the term sanitization was applied to printed documents; it has since been extended to apply to computer files and the problem of data remanence.
Government secrecy
In the context of government documents, redaction (also called sanitization) generally refers more specifically to the process of removing sensitive or classified information from a document prior to its publication, during declassification.
Secure document redaction techniques
Redacting confidential material from a paper document before its public release involves overwriting portions of text with a wide black pen, followed by photocopying the result—the obscured text may be recoverable from the original. Alternatively opaque "cover up tape" or "redaction tape", opaque, removable adhesive tape in various widths, may be applied before photocopying.
This is a simple process with only minor security risks. For example, if the black pen or tape is not wide enough, careful examination of the resulting photocopy may still reveal partial information about the text, such as the difference between short and tall letters. The exact length of the removed text also remains recognizable, which may help in guessing plausible wordings for shorter redacted sections. Where computer-generated proportional fonts were used, even more information can leak out of the redacted s |
https://en.wikipedia.org/wiki/Penultimate%20hop%20popping | Penultimate hop popping (PHP) is a function performed by certain routers in an MPLS enabled network. It refers to the process whereby the outermost label of an MPLS tagged packet is removed by a label switch router (LSR) before the packet is passed to an adjacent label edge router (LER). The benefit is that the LSR has to do a label lookup anyway and it doesn't make a difference whether this results in a label swap or pop. However, for the LER this saves one cycle of label lookup.
The process is important in a Layer 3 MPLS VPN () environment as it reduces the load on the LER. If this process didn't happen, the LER would have to perform at least 2 label lookups:
The outer label, identifying that the packet was destined to have its label stripped on this router.
The inner label, to identify which Virtual Routing and Forwarding (VRF) instance to use for the subsequent IP routing lookup.
In large, loaded networks the additional time required for second label lookup can make a difference in the overall forwarding performance and reduce buffering.
PHP functionality is achieved by the LER advertising a label with a value of 3 to its neighbours. This label is defined as "implicit-null" and informs the neighbouring LSR(s) to perform PHP.
External links
What Is PHP (Penultimate Hop Popping)
MPLS - Penultimate Hop Popping
MPLS PHP Lab
MPLS networking |
https://en.wikipedia.org/wiki/Spermatophylax | A spermatophylax is a gelatinous bolus which some male insects eject during copulation with females through their aedeagi together with spermatophores, and which functions as a nutritive supplement for the female.
See also
Nuptial gift |
https://en.wikipedia.org/wiki/Scalar%20field%20solution | In general relativity, a scalar field solution is an exact solution of the Einstein field equation in which the gravitational field is due entirely to the field energy and momentum of a scalar field. Such a field may or may not be massless, and it may be taken to have minimal curvature coupling, or some other choice, such as conformal coupling.
Definition
In general relativity, the geometric setting for physical phenomena is a Lorentzian manifold, which is physically interpreted as a curved spacetime, and which is mathematically specified by defining a metric tensor (or by defining a frame field). The curvature tensor of this manifold and associated quantities such as the Einstein tensor , are well-defined even in the absence of any physical theory, but in general relativity they acquire a physical interpretation as geometric manifestations of the gravitational field.
In addition, we must specify a scalar field by giving a function . This function is required to satisfy two following conditions:
The function must satisfy the (curved spacetime) source-free wave equation ,
The Einstein tensor must match the stress-energy tensor for the scalar field, which in the simplest case, a minimally coupled massless scalar field, can be written
.
Both conditions follow from varying the Lagrangian density for the scalar field, which in the case of a minimally coupled massless scalar field is
Here,
gives the wave equation, while
gives the Einstein equation (in the case where the field energy of the scalar field is the only source of the gravitational field).
Physical interpretation
Scalar fields are often interpreted as classical approximations, in the sense of effective field theory, to some quantum field. In general relativity, the speculative quintessence field can appear as a scalar field. For example, a flux of neutral pions can in principle be modeled as a minimally coupled massless scalar field.
Einstein tensor
The components of a tensor computed with re |
https://en.wikipedia.org/wiki/Lambdavacuum%20solution | In general relativity, a lambdavacuum solution is an exact solution to the Einstein field equation in which the only term in the stress–energy tensor is a cosmological constant term. This can be interpreted physically as a kind of classical approximation to a nonzero vacuum energy. These are discussed here as distinct from the vacuum solutions in which the cosmological constant is vanishing.
Terminological note: this article concerns a standard concept, but there is apparently no standard term to denote this concept, so we have attempted to supply one for the benefit of Wikipedia.
Definition
The Einstein field equation is often written as
with a so-called cosmological constant term . However, it is possible to move this term to the right hand side and absorb it into the stress–energy tensor , so that the cosmological constant term becomes just another contribution to the stress–energy tensor. When other contributions to that tensor vanish, the result
is a lambdavacuum. An equivalent formulation in terms of the Ricci tensor is
Physical interpretation
A nonzero cosmological constant term can be interpreted in terms of a nonzero vacuum energy. There are two cases:
: positive vacuum energy density and negative isotropic vacuum pressure, as in de Sitter space,
: negative vacuum energy density and positive isotropic vacuum pressure, as in anti-de Sitter space.
The idea of the vacuum having a nonvanishing energy density might seem counterintuitive, but this does make sense in quantum field theory. Indeed, nonzero vacuum energies can even be experimentally verified in the Casimir effect.
Einstein tensor
The components of a tensor computed with respect to a frame field rather than the coordinate basis are often called physical components, because these are the components which can (in principle) be measured by an observer. A frame consists of four unit vector fields
Here, the first is a timelike unit vector field and the others are spacelike unit vector fields, |
https://en.wikipedia.org/wiki/Pathfinding | Pathfinding or pathing is the plotting, by a computer application, of the shortest route between two points. It is a more practical variant on solving mazes. This field of research is based heavily on Dijkstra's algorithm for finding the shortest path on a weighted graph.
Pathfinding is closely related to the shortest path problem, within graph theory, which examines how to identify the path that best meets some criteria (shortest, cheapest, fastest, etc) between two points in a large network.
Algorithms
At its core, a pathfinding method searches a graph by starting at one vertex and exploring adjacent nodes until the destination node is reached, generally with the intent of finding the cheapest route. Although graph searching methods such as a breadth-first search would find a route if given enough time, other methods, which "explore" the graph, would tend to reach the destination sooner. An analogy would be a person walking across a room; rather than examining every possible route in advance, the person would generally walk in the direction of the destination and only deviate from the path to avoid an obstruction, and make deviations as minor as possible.
Two primary problems of pathfinding are (1) to find a path between two nodes in a graph; and (2) the shortest path problem—to find the optimal shortest path. Basic algorithms such as breadth-first and depth-first search address the first problem by exhausting all possibilities; starting from the given node, they iterate over all potential paths until they reach the destination node. These algorithms run in , or linear time, where V is the number of vertices, and E is the number of edges between vertices.
The more complicated problem is finding the optimal path. The exhaustive approach in this case is known as the Bellman–Ford algorithm, which yields a time complexity of , or quadratic time. However, it is not necessary to examine all possible paths to find the optimal one. Algorithms such as A* and Dijkstra' |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.