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https://en.wikipedia.org/wiki/Storage%20Resource%20Broker
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Storage Resource Broker (SRB) is data grid management computer software used in computational science research projects. SRB is a logical distributed file system based on a client-server architecture which presents users with a single global logical namespace or file hierarchy. Essentially, the software enables a user to use a single mechanism to work with multiple data sources.
Description
SRB provides a uniform interface to heterogeneous computer data storage resources over a network. As part of this, it implements a logical namespace (distinct from physical file names) and maintains metadata on data-objects (files), users, groups, resources, collections, and other items in an SRB metadata catalog (MCAT) stored in a relational database management system. System and user-defined metadata can be queried to locate files based on attributes as well as by name. SRB runs on various versions of Unix, Linux, and Microsoft Windows.
The SRB system is middleware in the sense that it is built on top of other major software packages (various storage systems, real-time data sources, a relational database management system, etc.) and it has callable library functions that can be utilized by higher level software. However, it is more complete than many middleware software systems as it implements a comprehensive distributed data management environment, including various end-user client applications. It has features to support the management and collaborative (and controlled) sharing, publication, replication, transfer, and preservation of distributed data collections.
SRB is sometimes used in conjunction with computational grid computing systems, such as Globus Alliance, and can utilize the Globus Alliance Grid Security Infrastructure (GSI) authentication system.
SRB can store and retrieve data in archival storage systems such as the High Performance Storage System and SAM-FS, on disk file systems (Unix, Linux, or Windows), as binary large objects or tabular data in relati
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https://en.wikipedia.org/wiki/Pension%20fund%20investment%20in%20infrastructure
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Infrastructure as an asset class
Although traditionally the preserve of governments and municipal authorities, infrastructure has recently become an asset class in its own right for private-sector investors, most notably pension funds.
Historically, pension funds have tended to invest mostly in "core assets" (such as money market instruments, government bonds, and large-cap equity) and, to a lesser extent, "alternative assets" (such as real estate, private equity and hedge funds). The average allocation to infrastructure historically represented only 1% of total assets under management by pensions, excluding indirect investment through ownership of stocks of listed utility and infrastructure companies.
However, government disengagement from the costly long-term financial commitments required by large infrastructure projects in the wake of the 2008–2012 global recession, combined with the realization that infrastructure could be an ideal asset class providing advantages such as long duration, facilitating cash flow matching with long-term liabilities, protection against inflation, and statistical diversification (i.e., a low correlation with "traditional" listed assets such as equities and fixed income), has prompted an increasing number of pension executives to consider investing in the infrastructure asset class. This macro-financial perspective on pension investment in infrastructure was developed by US, Canadian, and European financial economics and labor law experts, notably from Harvard Law School, the World Pensions Council, and the OECD.
Canadian, Californian, and Australian early entrants
Pension funds, including superannuation schemes, account for approximately 40% of all investors in the infrastructure asset class, excluding projects directly funded and developed by governments, municipalities, and public authorities. Large Canadian pension funds and sovereign investors have been particularly active in energy assets such as natural gas and natural gas
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https://en.wikipedia.org/wiki/Word%20%28group%20theory%29
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In group theory, a word is any written product of group elements and their inverses. For example, if x, y and z are elements of a group G, then xy, z−1xzz and y−1zxx−1yz−1 are words in the set {x, y, z}. Two different words may evaluate to the same value in G, or even in every group. Words play an important role in the theory of free groups and presentations, and are central objects of study in combinatorial group theory.
Definitions
Let G be a group, and let S be a subset of G. A word in S is any expression of the form
where s1,...,sn are elements of S, called generators, and each εi is ±1. The number n is known as the length of the word.
Each word in S represents an element of G, namely the product of the expression. By convention, the unique identity element can be represented by the empty word, which is the unique word of length zero.
Notation
When writing words, it is common to use exponential notation as an abbreviation. For example, the word
could be written as
This latter expression is not a word itself—it is simply a shorter notation for the original.
When dealing with long words, it can be helpful to use an overline to denote inverses of elements of S. Using overline notation, the above word would be written as follows:
Reduced words
Any word in which a generator appears next to its own inverse (xx−1 or x−1x) can be simplified by omitting the redundant pair:
This operation is known as reduction, and it does not change the group element represented by the word. Reductions can be thought of as relations (defined below) that follow from the group axioms.
A reduced word is a word that contains no redundant pairs. Any word can be simplified to a reduced word by performing a sequence of reductions:
The result does not depend on the order in which the reductions are performed.
A word is cyclically reduced if and only if every cyclic permutation of the word is reduced.
Operations on words
The product of two words is obtained by concatenation
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https://en.wikipedia.org/wiki/Wiener%20connector
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In network theory, the Wiener connector is a means of maximizing efficiency in connecting specified "query vertices" in a network. Given a connected, undirected graph and a set of query vertices in a graph, the minimum Wiener connector is an induced subgraph that connects the query vertices and minimizes the sum of shortest path distances among all pairs of vertices in the subgraph. In combinatorial optimization, the minimum Wiener connector problem is the problem of finding the minimum Wiener connector. It can be thought of as a version of the classic Steiner tree problem (one of Karp's 21 NP-complete problems), where instead of minimizing the size of the tree, the objective is to minimize the distances in the subgraph.
The minimum Wiener connector was first presented by Ruchansky et al. in 2015.
The minimum Wiener connector has applications in many domains where there is a graph structure and an interest in learning about connections between sets of individuals. For example, given a set of patients infected with a viral disease, which other patients should be checked to find the culprit? Or given a set of proteins of interest, which other proteins participate in pathways with them?
The Wiener connector was named in honor of chemist Harry Wiener who first introduced the Wiener Index.
Problem definition
The Wiener index is the sum of shortest path distances in a (sub)graph. Using to denote the shortest path between and , the Wiener index of a (sub)graph , denoted , is defined as
.
The minimum Wiener connector problem is defined as follows. Given an undirected and unweighted graph with vertex set and edge set and a set of query vertices , find a connector of minimum Wiener index. More formally, the problem is to compute
,
that is, find a connector that minimizes the sum of shortest paths in .
Relationship to Steiner tree
The minimum Wiener connector problem is related to the Steiner tree problem. In the former, the objective function in the minimizatio
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https://en.wikipedia.org/wiki/Total%20angular%20momentum%20quantum%20number
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In quantum mechanics, the total angular momentum quantum number parametrises the total angular momentum of a given particle, by combining its orbital angular momentum and its intrinsic angular momentum (i.e., its spin).
If s is the particle's spin angular momentum and ℓ its orbital angular momentum vector, the total angular momentum j is
The associated quantum number is the main total angular momentum quantum number j. It can take the following range of values, jumping only in integer steps:
where ℓ is the azimuthal quantum number (parameterizing the orbital angular momentum) and s is the spin quantum number (parameterizing the spin).
The relation between the total angular momentum vector j and the total angular momentum quantum number j is given by the usual relation (see angular momentum quantum number)
The vector's z-projection is given by
where mj is the secondary total angular momentum quantum number, and the is the reduced Planck's constant. It ranges from −j to +j in steps of one. This generates 2j + 1 different values of mj.
The total angular momentum corresponds to the Casimir invariant of the Lie algebra so(3) of the three-dimensional rotation group.
See also
Principal quantum number
Orbital angular momentum quantum number
Magnetic quantum number
Spin quantum number
Angular momentum coupling
Clebsch–Gordan coefficients
Angular momentum diagrams (quantum mechanics)
Rotational spectroscopy
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https://en.wikipedia.org/wiki/Critical%20field
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For a given temperature, the critical field refers to the maximum magnetic field strength below which a material remains superconducting. Superconductivity is characterized both by perfect conductivity (zero resistance) and by the complete expulsion of magnetic fields (the Meissner effect). Changes in either temperature or magnetic flux density can cause the phase transition between normal and superconducting states. The highest temperature under which the superconducting state is seen is known as the critical temperature. At that temperature even the weakest external magnetic field will destroy the superconducting state, so the strength of the critical field is zero. As temperature decreases, the critical field increases generally to a maximum at absolute zero.
For a type-I superconductor the discontinuity in heat capacity seen at the superconducting transition is generally related to the slope of the critical field () at the critical temperature ():
There is also a direct relation between the critical field and the critical current – the maximum electric current density that a given superconducting material can carry, before switching into the normal state. According to Ampère's law any electric current induces a magnetic field, but superconductors exclude that field. On a microscopic scale, the magnetic field is not quite zero at the edges of any given sample – a penetration depth applies. For a type-I superconductor, the current must remain zero within the superconducting material (to be compatible with zero magnetic field), but can then go to non-zero values at the edges of the material on this penetration-depth length-scale, as the magnetic field rises. As long as the induced magnetic field at the edges is less than the critical field, the material remains superconducting, but at higher currents, the field becomes too strong and the superconducting state is lost. This limit on current density has important practical implications in applications of supercondu
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https://en.wikipedia.org/wiki/Ferdinand%20Minding
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Ernst Ferdinand Adolf Minding (; – ) was a German-Russian mathematician known for his contributions to differential geometry. He continued the work of Carl Friedrich Gauss concerning differential geometry of surfaces, especially its intrinsic aspects. Minding considered questions of bending of surfaces and proved the invariance of geodesic curvature. He studied ruled surfaces, developable surfaces and surfaces of revolution and determined geodesics on the pseudosphere. Minding's results on the geometry of geodesic triangles on a surface of constant curvature (1840) anticipated Beltrami's approach to the foundations of non-Euclidean geometry (1868).
Career
Minding was largely self-taught in mathematics. He attended lectures in the University of Halle and eventually graduated with a thesis "De valore intergralium duplicium quam proxime inveniendo" (1829).
Minding worked as a teacher in Elberfeld and as a university lecturer in Berlin. His work on statics drew the attention of Alexander von Humboldt. However, his 1842 bid for election to Berlin Academy, supported by Peter Gustav Lejeune Dirichlet, failed and in 1843 he relocated to the University of Dorpat, where he was a professor of mathematics for the next 40 years. In Dorpat he taught Karl Peterson and supervised his doctoral thesis that established the Gauss–Bonnet theorem and derived Gauss–Codazzi equations. Minding also worked on differential equations (Demidov prize of the St Petersburg Academy in 1861), algebraic functions, continued fractions and analytical mechanics. His list of publications consists of some 60 titles, including several books. Many of his scientific accomplishments were only recognized properly after his death.
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https://en.wikipedia.org/wiki/Co%E2%80%93Star
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Co–Star is an American astrological social networking service founded in 2017, and headquartered in New York City. Users enter the date, time and place they were born to receive an astrological chart and daily horoscopes that they can compare to those of their friends.
History
Founder and CEO Banu Guler came up with the idea for the app after she gifted a friend's child an astrological chart that became a surprise hit at the baby shower. In 2019, Co–Star raised a $5.2 million seed round from Maveron, Aspect, and 14W, following a $750,000 pre-seed from Female Founders Fund in early 2018. In January 2020, Co–Star for Android was launched to a 120,000-person waitlist—two years after their iOS app was launched. In April 2021, Co–Star announced their $15 million Series A, led by Spark Capital. As of that date, Co–Star has more than 20 million downloads and has been downloaded by a quarter of all young women ages 18–25 in the U.S.
Features
Co–Star employs artificial intelligence to analyze publicly accessible NASA JPL data and find patterns in a user’s transits. Co–Star’s algorithm maps human-written snippets of text to planetary movements to display personalized content for each user. That content has been called “slightly robotic,” “wildly beautiful,” “truly insane," “brutally honest,” and compared to “a free therapy session.”
In July 2023, Co–Star released an in-app service called The Void that allows users to ask open-ended questions and receive answers informed by Co–Star's astrological database.
See also
Astrology
NASA
Timeline of social media
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https://en.wikipedia.org/wiki/Biophotonics
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The term biophotonics denotes a combination of biology and photonics, with photonics being the science and technology of generation, manipulation, and detection of photons, quantum units of light. Photonics is related to electronics and photons. Photons play a central role in information technologies, such as fiber optics, the way electrons do in electronics.
Biophotonics can also be described as the "development and application of optical techniques, particularly imaging, to the study of biological molecules, cells and tissue". One of the main benefits of using the optical techniques which make up biophotonics is that they preserve the integrity of the biological cells being examined.
Biophotonics has therefore become the established general term for all techniques that deal with the interaction between biological items and photons. This refers to emission, detection, absorption, reflection, modification, and creation of radiation from biomolecular, cells, tissues, organisms, and biomaterials. Areas of application are life science, medicine, agriculture, and environmental science.
Similar to the differentiation between "electric" and "electronics," a difference can be made between applications such as therapy and surgery, which use light mainly to transfer energy, and applications such as diagnostics, which use light to excite matter and to transfer information back to the operator. In most cases, the term biophotonics refers to the latter type of application.
Applications
Biophotonics is an interdisciplinary field involving the interaction between electromagnetic radiation and biological materials including: tissues, cells, sub-cellular structures, and molecules in living organisms.
Recent biophotonics research has created new applications for clinical diagnostics and therapies involving fluids, cells, and tissues. These advances are allowing scientists and physicians opportunities for superior, non-invasive diagnostics for vascular and blood flow, as well a
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https://en.wikipedia.org/wiki/Learning%20to%20rank
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Learning to rank or machine-learned ranking (MLR) is the application of machine learning, typically supervised, semi-supervised or reinforcement learning, in the construction of ranking models for information retrieval systems. Training data consists of lists of items with some partial order specified between items in each list. This order is typically induced by giving a numerical or ordinal score or a binary judgment (e.g. "relevant" or "not relevant") for each item. The goal of constructing the ranking model is to rank new, unseen lists in a similar way to rankings in the training data.
Applications
In information retrieval
Ranking is a central part of many information retrieval problems, such as document retrieval, collaborative filtering, sentiment analysis, and online advertising.
A possible architecture of a machine-learned search engine is shown in the accompanying figure.
Training data consists of queries and documents matching them together with the relevance degree of each match. It may be prepared manually by human assessors (or raters, as Google calls them), who check results for some queries and determine relevance of each result. It is not feasible to check the relevance of all documents, and so typically a technique called pooling is used — only the top few documents, retrieved by some existing ranking models are checked. This technique may introduce selection bias. Alternatively, training data may be derived automatically by analyzing clickthrough logs (i.e. search results which got clicks from users), query chains, or such search engines' features as Google's (since-replaced) SearchWiki. Clickthrough logs can be biased by the tendency of users to click on the top search results on the assumption that they are already well-ranked.
Training data is used by a learning algorithm to produce a ranking model which computes the relevance of documents for actual queries.
Typically, users expect a search query to complete in a short time (such as a f
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https://en.wikipedia.org/wiki/Magic%20constant
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The magic constant or magic sum of a magic square is the sum of numbers in any row, column, or diagonal of the magic square. For example, the magic square shown below has a magic constant of 15. For a normal magic square of order n – that is, a magic square which contains the numbers 1, 2, ..., n2 – the magic constant is .
For normal magic squares of orders n = 3, 4, 5, 6, 7, and 8, the magic constants are, respectively: 15, 34, 65, 111, 175, and 260 (sequence A006003 in the OEIS).
For example, a normal 8 × 8 square will always equate to 260 for each row, column, or diagonal.
The normal magic constant of order n is .
The largest magic constant of normal magic square which is also a:
triangular number is 15 (solve the Diophantine equation where y is divisible by 4);
square number is 1 (solve the Diophantine equation where y is even);
generalized pentagonal number is 171535 (solve the Diophantine equation where y is divisible by 12);
tetrahedral number is 2925.
Note that 0 and 1 are the only normal magic constants of rational order which are also rational squares.
However, there are infinitely many rational triangular numbers, rational generalized pentagonal numbers and rational tetrahedral numbers which are also magic constants of rational order.
The term magic constant or magic sum is similarly applied to other "magic" figures such as magic stars and magic cubes. Number shapes on a triangular grid divided into equal polyiamond areas containing equal sums give polyiamond magic constant.
Magic stars
The magic constant of an n-pointed normal magic star is .
Magic series
In 2013 Dirk Kinnaes found the magic series polytope. The number of unique sequences that form the magic constant is now known up to .
Moment of inertia
In the mass model, the value in each cell specifies the mass for that cell. This model has two notable properties. First it demonstrates the balanced nature of all magic squares. If such a model is suspended from the central cell the struct
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https://en.wikipedia.org/wiki/NOD%20mice
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Non-obese diabetic or NOD mice, like biobreeding rats, are used as an animal model for type 1 diabetes. Diabetes develops in NOD mice as a result of insulitis, a leukocytic infiltrate of the pancreatic islets. The onset of diabetes is associated with a moderate glycosuria and a non-fasting hyperglycemia. It is recommended to monitor for development of glycosuria from 10 weeks of age; this can be carried out using urine glucose dipsticks. NOD mice will develop spontaneous diabetes when left in a sterile environment. The incidence of spontaneous diabetes in the NOD mouse is 60–80% in females and 20–30% in males. Onset of diabetes also varies between males and females: commonly, onset is delayed in males by several weeks. The mice (as well as C57BL/6 and SJL) are known to carry IgG2c allele.
History
Non-obese diabetic (NOD) mice exhibit a susceptibility to spontaneous development of autoimmune insulin dependent diabetes mellitus (IDDM). The NOD strain and related strains were developed at Shionogi Research Laboratories in Aburahi, Japan by Makino and colleagues and first reported in 1980. The group developed the NOD strain by an outbreeding of the cataract-prone strain from JcI:ICR mice.
Susceptibility
The susceptibility to IDDM is polygenic and environment exerts a strong effect on gene penetrances. Environment including housing conditions, health status, and diet all affect development of diabetes in the mice. For instance, NOD mice maintained in different laboratories can have different levels of incidence. The incidence of disease is linked to the microbiome.
NOD mice are also susceptible to developing other autoimmune syndromes, including autoimmunine sialitis, autoimmune thyroiditis, autoimmune peripheral polyneuropathy etc. Diabetes in these mice can be prevented by a single injection of mycobacterial adjuvants such as complete Freund's adjuvant (FCA) or Bacille de Calmette et Guérin (BCG) vaccine.
Identifying IDDM susceptibility loci
Genetic Loci assoc
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https://en.wikipedia.org/wiki/Upstream%20contamination
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Upstream contamination by floating particles is a counterintuitive phenomenon in fluid dynamics. When pouring water from a higher container to a lower one, particles floating in the latter can climb upstream into the upper container. A definitive explanation is still lacking: experimental and computational evidence indicates that the contamination is chiefly driven by surface tension gradients, however the phenomenon is also affected by the dynamics of swirling flows that remain to be fully investigated.
Origins
The phenomenon was observed in 2008 by the Argentine Sebastian Bianchini during mate tea preparation, while studying physics at the University of Havana.
It rapidly attracted the interest of professor Alejandro Lage-Castellanos, who performed, with Bianchini, a series of controlled experiments. Later on professor Ernesto Altshuler completed the trio in Havana, which resulted in the Diploma thesis of Bianchini and a short original paper posted in the web arXiv and mentioned as a surprising fact in some online journals.
Bianchini's Diploma thesis showed that the phenomenon could be reproduced in a controlled laboratory setting using mate leaves or chalk powder as contaminants, and that temperature gradients (hot in the top, cold in the bottom) were not necessary to generate the effect. The research also showed that surface tension was key to the explanation through the Marangoni effect. This was suggested by two facts: (a) both mate and chalk lowered the surface tension of water, and (b) if an industrial surfactant was added on the upper reservoir, the upstream motion of particles would stop.
Confirmation
After a talk by Lage-Castellanos at the First Workshop on Complex Matter Physics in Havana (MarchCOMeeting'2012), professor Troy Shinbrot of Rutgers University became interested in the subject. Together with student Theo Siu, Cuban results were confirmed and expanded with new experiments and numerical simulations at Rutgers, which resulted in a joint pee
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https://en.wikipedia.org/wiki/Transitive%20reduction
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In the mathematical field of graph theory, a transitive reduction of a directed graph is another directed graph with the same vertices and as few edges as possible, such that for all pairs of vertices , a (directed) path from to in exists if and only if such a path exists in the reduction. Transitive reductions were introduced by , who provided tight bounds on the computational complexity of constructing them.
More technically, the reduction is a directed graph that has the same reachability relation as . Equivalently, and its transitive reduction should have the same transitive closure as each other, and the transitive reduction of should have as few edges as possible among all graphs with that property.
The transitive reduction of a finite directed acyclic graph (a directed graph without directed cycles) is unique and is a subgraph of the given graph. However, uniqueness fails for graphs with (directed) cycles, and for infinite graphs not even existence is guaranteed.
The closely related concept of a minimum equivalent graph is a subgraph of that has the same reachability relation and as few edges as possible. The difference is that a transitive reduction does not have to be a subgraph of . For finite directed acyclic graphs, the minimum equivalent graph is the same as the transitive reduction. However, for graphs that may contain cycles, minimum equivalent graphs are NP-hard to construct, while transitive reductions can be constructed in polynomial time.
Transitive reduction can be defined for an abstract binary relation on a set, by interpreting the pairs of the relation as arcs in a directed graph.
Classes of graphs
In directed acyclic graphs
The transitive reduction of a finite directed graph G is a graph with the fewest possible edges that has the same reachability relation as the original graph. That is, if there is a path from a vertex x to a vertex y in graph G, there must also be a path from x to y in the transitive reduction of G, and
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https://en.wikipedia.org/wiki/Acceptable%20Market%20Name
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In U.S. food regulations, an Acceptable Market Name is a set of guidelines for names of seafood sold in interstate commerce.
The Acceptable Market Names are recommendations, and not legally enforceable.
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https://en.wikipedia.org/wiki/Cap%27n%20Proto
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Cap’n Proto is a data serialization format and Remote Procedure Call (RPC) framework for exchanging data between computer programs. The high-level design focuses on speed and security, making it suitable for network as well as inter-process communication. Cap'n Proto was created by the former maintainer of Google's popular Protocol Buffers framework (Kenton Varda) and was designed to avoid some of its perceived shortcomings.
Technical overview
IDL Schema
Like most RPC frameworks dating as far back as Sun RPC and OSF DCE RPC (and their object-based descendants CORBA and DCOM), Cap'n Proto uses an Interface Description Language (IDL) to generate RPC libraries in a variety of programming languages - automating many low level details such as handling network requests, converting between data types, etc. The Cap'n Proto interface schema uses a C-like syntax and supports common primitives data types (booleans, integers, floats, etc.), compound types (structs, lists, enums), as well as generics and dynamic types. Cap'n Proto also supports Object Oriented features such as multiple inheritance, which has been criticized for its complexity. @0xa558ef006c0c123; #Unique identifiers are manually or automatically assigned to files and compound types
struct Date @0x5c5a558ef006c0c1 {
year @0 :Int16; #@n marks order values were added to the schema
month @1 :UInt8;
day @2 :UInt8;
}
struct Contact @0xf032a54bcb3667e0 {
name @0 :Text;
birthday @2 :Date; #fields can be added anywhere in the definition, but their numbering must reflect the order in which they were added
phones @1 :List(PhoneNumber);
struct PhoneNumber { #Compound types without an static ID cannot be renamed, as automatic IDs are deterministically generated
number @0 :Text;
type @1 :PhoneType = mobile; #Default value
enum PhoneType {
mobile @0;
landline @1;
}
}
}Values in Cap'n Proto messages are represented in binary, as opposed to text encoding used by "human-r
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https://en.wikipedia.org/wiki/Indicator%20bacteria
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Indicator bacteria are types of bacteria used to detect and estimate the level of fecal contamination of water. They are not dangerous to human health but are used to indicate the presence of a health risk.
Each gram of human feces contains approximately ~100 billion () bacteria. These bacteria may include species of pathogenic bacteria, such as Salmonella or Campylobacter, associated with gastroenteritis. In addition, feces may contain pathogenic viruses, protozoa and parasites. Fecal material can enter the environment from many sources including waste water treatment plants, livestock or poultry manure, sanitary landfills, septic systems, sewage sludge, pets and wildlife. If sufficient quantities are ingested, fecal pathogens can cause disease. The variety and often low concentrations of pathogens in environmental waters makes them difficult to test for individually. Public agencies therefore use the presence of other more abundant and more easily detected fecal bacteria as indicators of the presence of fecal contamination. Aside from bacteria being found in fecal matter, it can also be found in oral and gut contents.
Criteria for indicator organisms
The US Environmental Protection Agency (EPA) lists the following criteria for an organism to be an ideal indicator of fecal contamination:
The organism should be present whenever enteric pathogens are present
The organism should be useful for all types of water
The organism should have a longer survival time than the hardiest enteric pathogen
The organism should not grow in water
The organism should be found in warm-blooded animals’ intestines.
None of the types of indicator organisms that are currently in use fit all of these criteria perfectly, however, when cost is considered, use of indicators becomes necessary.
Types of indicator organisms
Commonly used indicator bacteria include total coliforms, or a subset of this group, fecal coliforms, which are found in the intestinal tracts of warm blooded animal
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https://en.wikipedia.org/wiki/Oscillator%20representation
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In mathematics, the oscillator representation is a projective unitary representation of the symplectic group, first investigated by Irving Segal, David Shale, and André Weil. A natural extension of the representation leads to a semigroup of contraction operators, introduced as the oscillator semigroup by Roger Howe in 1988. The semigroup had previously been studied by other mathematicians and physicists, most notably Felix Berezin in the 1960s. The simplest example in one dimension is given by SU(1,1). It acts as Möbius transformations on the extended complex plane, leaving the unit circle invariant. In that case the oscillator representation is a unitary representation of a double cover of SU(1,1) and the oscillator semigroup corresponds to a representation by contraction operators of the semigroup in SL(2,C) corresponding to Möbius transformations that take the unit disk into itself.
The contraction operators, determined only up to a sign, have kernels that are Gaussian functions. On an infinitesimal level the semigroup is described by a cone in the Lie algebra of SU(1,1) that can be identified with a light cone. The same framework generalizes to the symplectic group in higher dimensions, including its analogue in infinite dimensions. This article explains the theory for SU(1,1) in detail and summarizes how the theory can be extended.
Historical overview
The mathematical formulation of quantum mechanics by Werner Heisenberg and Erwin Schrödinger was originally in terms of unbounded self-adjoint operators on a Hilbert space. The fundamental operators corresponding to position and momentum satisfy the Heisenberg commutation relations. Quadratic polynomials in these operators, which include the harmonic oscillator, are also closed under taking commutators.
A large amount of operator theory was developed in the 1920s and 1930s to provide a rigorous foundation for quantum mechanics. Part of the theory was formulated in terms of unitary groups of operators, largely
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https://en.wikipedia.org/wiki/Eccentricity%20%28behavior%29
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Eccentricity (also called quirkiness) is an unusual or odd behavior on the part of an individual. This behavior would typically be perceived as unusual or unnecessary, without being demonstrably maladaptive. Eccentricity is contrasted with normal behavior, the nearly universal means by which individuals in society solve given problems and pursue certain priorities in everyday life. People who consistently display benignly eccentric behavior are labeled as "eccentrics".
Etymology
From Medieval Latin eccentricus, derived from Greek , "out of the center", from -, - "out of" + , "center". Eccentric first appeared in English essays as a neologism in 1551 as an astronomical term meaning "a circle in which the earth, sun, etc. deviates from its center." Five years later, in 1556, an adjective form of the word was used. In 1685, the definition evolved from the literal to the figurative, and eccentric is noted to have begun being used to describe unconventional or odd behavior. A noun form of the word – a person who possesses and exhibits these unconventional or odd qualities and behaviors – appeared by 1832.
Depictions
Eccentricity is often associated with genius, intellectual giftedness, or creativity. People may perceive the individual's eccentric behavior as the outward expression of their unique intelligence or creative impulse. In this vein, the eccentric's habits are incomprehensible not because they are illogical or the result of madness, but because they stem from a mind so original that it cannot be conformed to societal norms. English utilitarian thinker John Stuart Mill (1806–1873) wrote that "the amount of eccentricity in a society has generally been proportional to the amount of genius, mental vigour, and moral courage which it contained", and mourned a lack of eccentricity as "the chief danger of the time". Edith Sitwell (1887–1964) wrote that eccentricity is "often a kind of innocent pride", also saying that geniuses and aristocrats are called eccentrics b
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https://en.wikipedia.org/wiki/Phosphohydroxypyruvic%20acid
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Phosphohydroxypyruvic acid is an organic acid most widely known as an intermediate in the synthesis of serine.
Chemical properties
Phosphohydroxypyruvic acid is a moderately weak acid.
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https://en.wikipedia.org/wiki/Pachyosteosclerosis
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Pachyosteosclerosis is a combination of thickening (pachyostosis) and densification (osteosclerosis) of bones. It makes bones more heavy, but also more fragile. The condition often occurs in aquatic vertebrates, especially those living in shallow waters, creating ballast as an adaptation for maintaining neutral buoyancy and horizontal trim. It is in no way pathological. To resist bend, it frequently is found especially in ventral bones, whereas concentration near the lungs helps in maintaining trim.
Examples of animals showing pachyosteosclerosis are seacows (dugongs and manatees), the extinct Plesiosauria and Mesosauria and extinct aquatic sloths.
See also
Pachyostosis
Osteosclerosis
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https://en.wikipedia.org/wiki/Dough%20conditioner
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A dough conditioner, flour treatment agent, improving agent or bread improver is any ingredient or chemical added to bread dough to strengthen its texture or otherwise improve it in some way. Dough conditioners may include enzymes, yeast nutrients, mineral salts, oxidants and reductants, bleaching agents and emulsifiers. They are food additives combined with flour to improve baking functionality. Flour treatment agents are used to increase the speed of dough rising and to improve the strength and workability of the dough.
Examples
Examples of dough conditioners include ascorbic acid, distilled monoglycerides, citrate ester of monoglycerides, diglycerides, ammonium chloride, enzymes, diacetyl tartaric acid ester of monoglycerides or DATEM, potassium bromate, calcium salts such as calcium iodate, L-cystine, L-cysteine HCl, glycerol monostearate, azodicarbonamide, sodium stearoyl lactylate, sucrose palmitate or sucrose ester, polyoxyethylene sorbitan monostearate or polysorbate, soybean lecithin, and soybean lecithin enriched with lysophospholipids.
Less processed dough conditioners include sprouted- or malted-grain flours, soy, milk, wheat germ, eggs, potatoes, gluten, yeast, and extra kneading. Malted, diastatic flours are not typically added by manufacturers to whole-wheat flours.
History
In the early 1900s it was discovered the use of calcium chloride, ammonium sulfate, and potassium bromate halved the amount of yeast needed to raise dough. These mixtures were generally known as mineral yeast foods or yeast nutrient salts. After they became popular among bakers, one patented yeast food was analyzed by Connecticut Agricultural Experiment Station chief chemist J.P. Street who published in 1917 that it contained, "calcium sulphate, 25; ammonium chlorid, 9.7; potassium bromate, 0.3; sodium chlorid, 25; patent wheat flour, 40." They contain water conditioners, yeast conditioners, and dough conditioners.
Yeast nutrients
Yeast requires water, carbon sources such as
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https://en.wikipedia.org/wiki/Software%20safety%20classification
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Software installed in medical devices is assessed for health and safety issues according to international standards.
Safety classes
Software classification is based on the potential for hazard(s) that could cause injury to the user or patient.
Per [[IEC 62304|IEC 62304:2006] + A1:2015], the software can be divided into three separate classes:
The SOFTWARE SYSTEM is software safety class A if:
the SOFTWARE SYSTEM cannot contribute to a HAZARDOUS SITUATION; or
the SOFTWARE SYSTEM can contribute to a HAZARDOUS SITUATION which does not result in unacceptable RISK after consideration of RISK CONTROL measures external to the SOFTWARE SYSTEM.
The SOFTWARE SYSTEM is software safety class B if:
the SOFTWARE SYSTEM can contribute to a HAZARDOUS SITUATION which results in unacceptable RISK after consideration of RISK CONTROL measures external to the SOFTWARE SYSTEM and the resulting possible HARM is non-SERIOUS INJURY.
The SOFTWARE SYSTEM is software safety class C if:
the SOFTWARE SYSTEM can contribute to a HAZARDOUS SITUATION which results in unacceptable RISK after consideration of RISK CONTROL measures external to the SOFTWARE SYSTEM and the resulting possible HARM is death or SERIOUS INJURY“
Serious injury
For the purpose of this classification, serious injury is defined as injury or illness that directly or indirectly is life threatening; results in permanent impairment of a body function or permanent damage to a body structure; or necessitates medical or surgical intervention to prevent permanent impairment of a body function or permanent damage to a body structure.
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https://en.wikipedia.org/wiki/Microbial%20toxin
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Microbial toxins are toxins produced by micro-organisms, including bacteria, fungi, protozoa, dinoflagellates, and viruses. Many microbial toxins promote infection and disease by directly damaging host tissues and by disabling the immune system. Endotoxins most commonly refer to the lipopolysaccharide (LPS) or lipooligosaccharide (LOS) that are in the outer plasma membrane of Gram-negative bacteria. The botulinum toxin, which is primarily produced by Clostridium botulinum and less frequently by other Clostridium species, is the most toxic substance known in the world. However, microbial toxins also have important uses in medical science and research. Currently, new methods of detecting bacterial toxins are being developed to better isolate and understand these toxins. Potential applications of toxin research include combating microbial virulence, the development of novel anticancer drugs and other medicines, and the use of toxins as tools in neurobiology and cellular biology.
Bacterial
Bacteria toxins which can be classified as either exotoxins or endotoxins. Exotoxins are generated and actively secreted; endotoxins remain part of the bacteria. Usually, an endotoxin is part of the bacterial outer membrane, and it is not released until the bacterium is killed by the immune system. The body's response to an endotoxin can involve severe inflammation. In general, the inflammation process is usually considered beneficial to the infected host, but if the reaction is severe enough, it can lead to sepsis. Exotoxins are typically proteins with enzymatic activity that interfere with host cells triggering the symptoms associated with the disease. Exotoxins are also relatively specific to the bacteria that produce it; for example, diphtheria toxin is only produced by Corynebacterium diphtheriae bacteria and is required for the diphtheria disease. Some bacterial toxins can be used in the treatment of tumors. Endotoxins most commonly refer to the lipopolysaccharide (LPS) or li
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https://en.wikipedia.org/wiki/Soft%20Growing%20Robotics
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Soft Growing Robotics is a subset of soft robotics concerned with designing and building robots that use robot body expansion to move and interact with the environment.
Soft growing robots are built from compliant materials and attempt to mimic how vines, plant shoots, and other organisms reach new locations through growth. While other forms of robots use locomotion to achieve their objectives, soft growing robots elongate their body through addition of new material, or expansion of material. This gives them the ability to travel through constricted areas and form a wide range of useful 3-D formations. Currently there are two main soft growing robot designs: additive manufacturing and tip extension. Some goals of soft growing robotics development are the creation of robots that can explore constricted areas and improve surgical procedures.
Additive manufacturing design
One way of extending the robot body is through additive manufacturing. Additive manufacturing generally refers to 3-D printing, or the fabrication of three dimensional objects through the conjoining of many layers of material. Additive manufacturing design of a soft growing robot utilizes a modified 3-D printer at the tip of the robot to deposit thermoplastics (material that is rigid when cooled and flexible when heated) to extend the robot in the desired orientation.
Design characteristics
The body of the robot consists of:
A base, where the power supply, circuit board, and spool of thermoplastic filament is stored.
The tubular body of varying length created by additive manufacturing which extends outwards from the base.
The tip where new material is deposited to lengthen the tubular body, and house sensors.
The additive manufacturing process involves polylactic acid filament (a thermoplastic) being pulled through the tubular body of the robot by a motor in the tip. At the tip, the filament passes through a heating element, making it pliable. The filament is then turned perpendicular to the
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https://en.wikipedia.org/wiki/Endiandric%20acid%20C
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Endiandric acid C, isolated from the tree Endiandra introrsa, is a well characterized chemical compound. Endiadric acid C is reported to have better antibiotic activity than ampicillin.
This genus of trees is in the family Lauraceae. These trees are found in the north-eastern Australian rainforests and other tropical and subtropical regions. However, they are also found in southern Canada and in Chile. Endiandric acid C is also isolated from the species E. xanthocarpa. Endiandric acids are also found in Beilschmiedia trees, which were categorized under the genus Endiandra, but moved to their own genus as they found in cold, high latitude areas, and even in New Zealand. Other endiandric acids are found in B. oligandra and B. anacardioides, which are found in the Western Province of Cameroon.
Bioactivity
This compound has the best antibacterial activity of Endiandrianic acid A-G compounds. Endiandric acid C was tested towards five strains of bacteria, which included Bacillus subtilis, Micococcus luteus, Streptococcus faecalis, Pseudomonas palida, and Escherichia coli through examining zone inhibition and minimum concentration, which was found to range between 0.24 µg/mL and 500 µg/mL. Endiandric acid C has also been used to cure uterine tumors, rubella, and female genital infections, and rheumatisms.
Biosynthesis
Many biochemists predicted when examining K. C. Nicolaou's biomimetic synthesis of the endiandric acid cascade that enzymes aided this reaction in the biosynthesis. The biomimetic series determined that this process took place synthetically through a series of Diels-Alder cyclization reactions and therefore led researches to believe that Diels-Alderase assisted the formation of endiandric acid C.
Although it has been discovered since then that many famous cyclization reactions like that of lovastatin do result from the Diels-Alderase they have determine that the endiandric acid cascade does not involve enzymes but rather spontaneously undergoes rin
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https://en.wikipedia.org/wiki/Entoptic%20phenomenon
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Entoptic phenomena () are visual effects whose source is within the human eye itself. (Occasionally, these are called entopic phenomena, which is probably a typographical mistake.)
In Helmholtz's words: "Under suitable conditions light falling on the eye may render visible certain objects within the eye itself. These perceptions are called entoptical."
Overview
Entoptic images have a physical basis in the image cast upon the retina. Hence, they are different from optical illusions, which are caused by the visual system and characterized by a visual percept that (loosely said) appears to differ from reality. Because entoptic images are caused by phenomena within the observer's own eye, they share one feature with optical illusions and hallucinations: the observer cannot share a direct and specific view of the phenomenon with others.
Helmholtz commented on entoptic phenomena which could be seen easily by some observers, but could not be seen at all by others. This variance is not surprising because the specific aspects of the eye that produce these images are unique to each individual. Because of the variation between individuals, and the inability for two observers to share a nearly identical stimulus, these phenomena are unlike most visual sensations. They are also unlike most optical illusions which are produced by viewing a common stimulus. Yet, there is enough commonality between the main entoptic phenomena that their physical origin is now well understood.
Examples
Some examples of entoptical effects include:
Floaters or muscae volitantes are slowly drifting blobs of varying size, shape, and transparency, which are particularly noticeable when viewing a bright, featureless background (such as the sky) or a point source of diffuse light very close to the eye. They are shadow images of objects floating in liquid between the retina and the gel inside the eye (vitreous humor). They are visible because they move; if they were pinned to retina by the vitreous o
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https://en.wikipedia.org/wiki/Sug%20Woo%20Shin
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Sug Woo Shin is a professor of mathematics at the University of California, Berkeley working in number theory, automorphic forms, and the Langlands program.
Education
From 1994 to 1996 when he was in Seoul Science High School, Shin won two gold medals (including a perfect score in 1995) and one bronze medal while representing South Korea at the International Mathematical Olympiad.
He graduated from Seoul National University with a Bachelor of Science degree in mathematics in 2000. He received his PhD in mathematics from Harvard University in 2007 under the supervision of Richard Taylor.
Career
Shin was a member of the Institute for Advanced Study from 2007 to 2008, a Dickson Instructor at the University of Chicago from 2008 to 2010, and again a member at the Institute for Advanced Study from 2010 to 2011. He was an assistant professor of mathematics at the Massachusetts Institute of Technology from 2011 to 2014. In 2014, Shin moved to the Department of Mathematics at the University of California, Berkeley as an associate professor. In 2020, Shin became a full professor of mathematics at the University of California, Berkeley.
Shin is a visiting KIAS scholar at the Korea Institute for Advanced Study and a visiting associate member of the Pohang Mathematics Institute.
Research
In 2011, Michael Harris and Shin resolved the dependencies on improved forms of the Arthur–Selberg trace formula in the conditional proofs of generalizations of the Sato–Tate conjecture by Harris (for products of non-isogenous elliptic curves) and Barnet-Lamb–Geraghty–Harris–Taylor (for arbitrary non-CM holomorphic modular forms of weight greater than or equal to two).
Awards
Shin received a Sloan Fellowship in 2013.
Selected publications
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https://en.wikipedia.org/wiki/Biological%20pollution
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Biological pollution (impacts or bio pollution) is the impact of humanity's actions on the quality of aquatic and terrestrial environment. Specifically, biological pollution is the introduction of non-indigenous and invasive species, otherwise known as Invasive Alien Species (IAS). When the biological pollution is introduced to an aquatic environment, it contributes to water pollution.
Biopollution may cause adverse effects at several levels of biological organization:
an individual organism (internal pollution by parasites or pathogens),
a population (by genetic change, i.e. hybridization of IAS with a native species),
a community or biocoenosis (by structural shifts, i.e. dominance of IAS, replacement or elimination of native species),
a habitat (by modification of physical-chemical conditions),
an ecosystem (by alteration of energy and organic material flow).
Biopollution may also cause decline in naturalness of nature conservation areas, adverse economic consequences and impacts on human health. The notion of "biological pollution" and "biological pollutants" described by Elliott (2003) is generally accepted in invasion biology; it was used to develop the concept of biopollution level assessment (Olenin et al., 2007) and criteria for a Good Ecological Status descriptor in the European Marine Strategy Framework Directive (Olenin et al., 2010)
The magnitude of the bioinvasion impact or biopollution level (Olenin et al., 2007) may be quantified using a free online service BINPAS.
In 1991 The Indiana Academy of Science held a national cross disciplinary conference in Indianapolis (McKnight 1993), the first of its find dealing with the issue.
Biopollution level
"Biopollution Level (BPL)" is a quantitative measure of the magnitude of the biological invasion impact, ranging from "no impact" (BPL=0) through "weak" (BPL=1), "moderate" (BPL=2), "strong" (BPL=3) and "massive" (BPL=4) impact.
Initially the method of calculation involves assessing the abundance a
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https://en.wikipedia.org/wiki/Davies%20equation
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The Davies equation is an empirical extension of Debye–Hückel theory which can be used to calculate activity coefficients of electrolyte solutions at relatively high concentrations at 25 °C. The equation, originally published in 1938, was refined by fitting to experimental data. The final form of the equation gives the mean molal activity coefficient of an electrolyte that dissociates into ions having charges and as a function of ionic strength :
The second term, , goes to zero as the ionic strength goes to zero, so the equation reduces to the Debye–Hückel equation at low concentration. However, as concentration increases, the second term becomes increasingly important, so the Davies equation can be used for solutions too concentrated to allow the use of the Debye–Hückel equation. For 1:1 electrolytes the difference between measured values and those calculated with this equation is about 2% of the value for 0.1 M solutions. The calculations become less precise for electrolytes that dissociate into ions with higher charges. Further discrepancies will arise if there is association between the ions, with the formation of ion pairs, such as .
See also
Osmotic coefficient
Pitzer equations
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https://en.wikipedia.org/wiki/Motility
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Motility is the ability of an organism to move independently, using metabolic energy.
Definitions
Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms that do not possess a means of self-locomotion and are normally immobile.
Motility differs from mobility, the ability of an object to be moved.
The term vagility encompasses both motility and mobility; sessile organisms including plants and fungi often have vagile parts such as fruits, seeds, or spores which may be dispersed by other agents such as wind, water, or other organisms.
Motility is genetically determined, but may be affected by environmental factors such as toxins. The nervous system and musculoskeletal system provide the majority of mammalian motility.
In addition to animal locomotion, most animals are motile, though some are vagile, described as having passive locomotion. Many bacteria and other microorganisms, and multicellular organisms are motile; some mechanisms of fluid flow in multicellular organs and tissue are also considered instances of motility, as with gastrointestinal motility. Motile marine animals are commonly called free-swimming, and motile non-parasitic organisms are called free-living.
Motility includes an organism's ability to move food through its digestive tract. There are two types of intestinal motility – peristalsis and segmentation. This motility is brought about by the contraction of smooth muscles in the gastrointestinal tract which mix the luminal contents with various secretions (segmentation) and move contents through the digestive tract from the mouth to the anus (peristalsis).
Cellular level
At the cellular level, different modes of movement exist:
amoeboid movement, a crawling-like movement, which also makes swimming possible
filopodia, enabling movement of the axonal growth cone
flagellar motility, a swimming-like motion (observed for example in spermatozoa, propelled by
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https://en.wikipedia.org/wiki/Nomina%20Anatomica%20Veterinaria
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The Nomina Anatomica Veterinaria (often abbreviated as NAV) is an standardized nomenclature. It is made by World Association of Veterinary Anatomists (WAVA). It is used as the standard reference for anatomical (zootomical) terminology in the field of veterinary science regarding domestic mammals (domestic birds are regarded in the Nomina Anatomica Avium). It is based on cats, dogs, pigs, cows, sheep, goats, rabbits and horses—horses being their main subjects.
History
Veterinary anatomists split at the 5th International Congress of the International Anatomical Nomenclature Committee in Paris in 1955, due to disagreements about the Nomina Anatomica. Following professor Clement Bressou in 1957 in Freiburg (Germany), they formed the International Committee on Veterinary Anatomical Nomenclature, renamed World Association of Veterinary Anatomists in 1961, and published the first edition of the Nomina Anatomica Veterinaria (NAV) in 1968. There have been sixth editions of the NAV, the latest one published in 2017. The 4th edition, published in 1994, was the last commercially printed edition, fifth and sixth edition are available in pdf.
See also
Nomina Anatomica
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https://en.wikipedia.org/wiki/Cyber-kinetic%20attack
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A cyber-kinetic attack targets cyber-physical systems and causes direct or indirect physical damage, injury or death, or environmental impact solely through the exploitation of vulnerable information systems and processes. Notable attacks in this category in the recent past have targeted critical infrastructure facilities such as water treatment plants, nuclear power plants, oil refineries, and medical facilities.
Crossing the cyber-physical divide
In the early days of computing, security threats were typically limited attacks that caused destruction of data, or degraded access to computing systems or hardware. However, the last several decades have seen technologies—ranging from supervisory control and data acquisition (SCADA) to Internet of Things—which describe objects embedded with sensors and software and utilize the Internet to exchange data.
Such a system is termed as a Cyber-physical system. Such systems cross the traditional divide between purely in-computer systems (software) and real-life systems (physical systems), with algorithms being autonomously able to control physical systems.
One of the most notably cyber attacks that had a physical impact, causing significant degradation of a target system, were the Stuxnet and Aurora worms. The Stuxnet worm was first revealed in 2010 and specially targeted weaknesses in Programmable Logic Controllers (PLCs), devices in the SCADA category of systems. Though it was never positivity attributed, it is widely believed that the malicious software was developed jointly by the United States and Israel to disrupt the Iranian nuclear enrichment facility at Natanz. It has also been reported that Stuxnet and associated variants have infected more than 30,000 systems and had a lasting presence which was extremely difficult to eradicate and purify. Both malicious programs exploited Zero-Day attacks on Windows-based operating systems.
As computing crosses the cyber-physical barrier, there is significant effort spent o
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https://en.wikipedia.org/wiki/KCNAB3
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Voltage-gated potassium channel subunit beta-3 is a protein that in humans is encoded by the KCNAB3 gene. The protein encoded by this gene is a voltage-gated potassium channel beta subunit.
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https://en.wikipedia.org/wiki/Depositional%20resolution
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In geology, the depositional resolution is the age span of objects that are contained within a stratum. In most cases the objects of interest are grains or fossils.
Limit cases
One limit case with an extremely low depositional resolution is a reworked fossil in a younger bed. Here the stratigraphic resolution is approximately the time span between the deposition of the bed and the first deposition of the reworked fossil.
The counterpart would be an environment that is rapidly covered in sediment, which kills and preserves all life present. Even in such cases there will still be some death assemblage around that has been generated beforehand. This puts a limit on the depositional resolution.
Depositional resolution and stratigraphic resolution
Depositional resolution and stratigraphic resolution are different concepts. This is since stratigraphic resolution is based on the relation between different strata, whereas depositional resolution is a property within one stratum. Stratigraphic resolution can be higher than depositional resolution and vice versa. But since both are to some extent affected by the same controlling factors they can correlate.
Literature
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https://en.wikipedia.org/wiki/Universal%20causation
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Universal causation is the proposition that everything in the universe has a cause and is thus an effect of that cause. This means that if a given event occurs, then this is the result of a previous, related event. If an object is in a certain state, then it is in that state as a result of another object interacting with it previously.
The idea of universal causation is formulated in western philosophy similarly for ages, however the formulations contain some profound differences in methodology and philosophical assumptions.
Examples:
In contrast, Bertrand Russell argued (in 1912) that the law of causation as usually stated by philosophers is false and is not used in sciences (maybe with exception of their infancy). However his position on universal causation evolved and "was not as naive as it may have appeared". In 1927 Russell writes that the notion of universal causation marks the beginnings of science and philosophy.
Philosophers who do believe in exception-less, universal, fundamental laws of nature are in recent times more often referred to as "fundamentalists", however these who present "anti-laws" efforts (for instance showing that in many cases laws of sciences are ceteris paribus laws) "pluralists" are in the minority.
As axioms of causality
According to William Whewell (hypothetico-deductivist view) the concept of universal causation depends on three axioms:
Nothing takes place without a cause.
The magnitude of an effect is proportional to the magnitude of its cause.
To every action there is an equal and opposed reaction.
Whewell writes that the first axiom is so clear that it requires no proof if only the idea of cause is understood.
Example
Example for the axiom: if a baseball is moving through the air, it must be moving this way because of a previous interaction with another object, such as being hit by a baseball bat.
Criticism
An epistemological axiom is a self-evident truth. Thus the "Axiom of Causality" claims to be a universal rule tha
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https://en.wikipedia.org/wiki/Six-bit%20character%20code
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A six-bit character code is a character encoding designed for use on computers with word lengths a multiple of 6. Six bits can only encode 64 distinct characters, so these codes generally include only the upper-case letters, the numerals, some punctuation characters, and sometimes control characters. The 7-track magnetic tape format was developed to store data in such codes, along with an additional parity bit.
Types of six-bit codes
An early six-bit binary code was used for Braille, the reading system for the blind that was developed in the 1820s.
The earliest computers dealt with numeric data only, and made no provision for character data. Six-bit BCD, with several variants, was used by IBM on early computers such as the IBM 702 in 1953 and the IBM 704 in 1954. Six-bit encodings were replaced by the 8-bit EBCDIC code starting in 1964, when System/360 standardized on 8-bit bytes. There are some variants of this type of code (see below).
Six-bit character codes generally succeeded the five-bit Baudot code and preceded seven-bit ASCII.
Six-bit codes could encode more than 64 characters by the use of Shift Out and Shift In characters, essentially incorporating two distinct 62-character sets and switching between them. For example, the popular IBM 2741 communications terminal supported a variety of character sets of up to 88 printing characters plus control characters.
BCD six-bit code
Six-bit BCD code was the adaptation of the punched card code to binary code. IBM applied the terms binary-coded decimal and BCD to the variations of BCD alphamerics used in most early IBM computers, including the IBM 1620, IBM 1400 series, and non-decimal architecture members of the IBM 700/7000 series.
COBOL databases six-bit code
A six-bit code was also used in COBOL databases, where end-of-record information was stored separately.
Magnetic stripe card six-bit code
A six-bit code, with added odd parity bit, is used on Track 1 of magnetic stripe cards, as specified in ISO/IEC 78
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https://en.wikipedia.org/wiki/Five%20prime%20untranslated%20region
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The 5′ untranslated region (also known as 5′ UTR, leader sequence, transcript leader, or leader RNA) is the region of a messenger RNA (mRNA) that is directly upstream from the initiation codon. This region is important for the regulation of translation of a transcript by differing mechanisms in viruses, prokaryotes and eukaryotes. While called untranslated, the 5′ UTR or a portion of it is sometimes translated into a protein product. This product can then regulate the translation of the main coding sequence of the mRNA. In many organisms, however, the 5′ UTR is completely untranslated, instead forming a complex secondary structure to regulate translation.
The 5′ UTR has been found to interact with proteins relating to metabolism, and within the 5′ UTR. In addition, this region has been involved in transcription regulation, such as the sex-lethal gene in Drosophila. Regulatory elements within 5′ UTRs have also been linked to mRNA export.
General structure
Length
The 5′ UTR begins at the transcription start site and ends one nucleotide (nt) before the initiation sequence (usually AUG) of the coding region. In prokaryotes, the length of the 5′ UTR tends to be 3–10 nucleotides long, while in eukaryotes it tends to be anywhere from 100 to several thousand nucleotides long. For example, the ste11 transcript in Schizosaccharomyces pombe has a 2273 nucleotide 5′ UTR while the lac operon in Escherichia coli only has seven nucleotides in its 5′ UTR. The differing sizes are likely due to the complexity of the eukaryotic regulation which the 5′ UTR holds as well as the larger pre-initiation complex that must form to begin translation.
The 5′ UTR can also be completely missing, in the case of leaderless mRNAs. Ribosomes of all three domains of life accept and translate such mRNAs. Such sequences are naturally found in all three domains of life. Humans have many pressure-related genes under a 2–3 nucleotide leader. Mammals also have other types of ultra-short leaders like t
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https://en.wikipedia.org/wiki/Type%20IV%20collagen%20C4%20domain
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In molecular biology, the type IV collagen C4 domain (or collagen IV NC1 domain) is a duplicated domain present at the C-terminus of type IV collagens. Each type IV collagen contains a long triple-helical collagenous domain flanked by a short 7S domain of 25 amino acids and a globular non-collagenous C4 domain of ~230 amino acids at the N and C terminus, respectively. In protomer assembly, the C4 domains of three chains interact, forming a C4 trimer, to select and register chains for triple helix formation. In network assembly, the C4 trimers of two protomers interact, forming a C4 hexamer structure, to select and connect protomers.
The collagen IV C4 domain contains 12 cysteines, and all of them are involved in disulphide bonds. It folds into a tertiary structure with predominantly beta-strands. The collagen IV C4 domain is composed of two similarly folded subdomains stabilised by 3 intrachain disulphide bonds involving the following pairs: C1-C6, C2-C5, and C3-C4. Each subdomain represents a compact disulphide-stabilised triangular structure, from which a finger-like hairpin loop projects into an incompletely formed six-stranded beta-sheet of an adjacent subdomain of the same or of an adjacent chain clamping the subdomains tightly together.
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https://en.wikipedia.org/wiki/Haramiyida
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Haramiyida is a possibly polyphyletic order of mammaliaform cynodonts or mammals of controversial taxonomic affinites. Their teeth, which are by far the most common remains, resemble those of the multituberculates. However, based on Haramiyavia, the jaw is less derived; and at the level of evolution of earlier basal mammals like Morganucodon and Kuehneotherium, with a groove for ear ossicles on the dentary. Some authors have placed them in a clade with Multituberculata dubbed Allotheria within Mammalia. Other studies have disputed this and suggested the Haramiyida were not crown mammals, but were part of an earlier offshoot of mammaliaformes instead. It is also disputed whether the Late Triassic species are closely related to the Jurassic and Cretaceous members belonging to Euharamiyida/Eleutherodontida, as some phylogenetic studies recover the two groups as unrelated, recovering the Triassic haramiyidians as non-mammalian cynodonts, while recovering the Euharamiyida as crown-group mammals closely related to multituberculates.
Relationships
Haramiyids show certain similarities to multituberculates, a group of mammals that survived until about 40 million years ago. It is possible that haramiyids are ancestral to multituberculates, although the available evidence is insufficient to be conclusive. Certain characteristics of the teeth seem to rule out a special relationship between the two groups, although some studies still unite haramiyids (or at least euharamiyids) and multituberculates in the Allotheria hypothesis.
In a 2018 study, haramiyidans have been found to be a monophyletic group of non-mammalian Mammaliaformes. In this study, gondwanatheres – usually interpreted as mammals, and derived multituberculates in particular – have been found to be deeply nested among them.
Taxonomy
Order †Haramiyida Hahn, Sigogneau-Russell & Wouters, 1989 [Haramiyoidea Hahn, 1973 sensu McKenna & Bell, 1997]
†Kirtlingtonia Butler & Hooker, 2005
Family †Haramiyaviidae Butler, 2
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https://en.wikipedia.org/wiki/Smalleye%20whip%20ray
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The smalleye whip ray (Himantura microphthalma) is an obscure species of stingray in the family Dasyatidae. It is known only from a single specimen collected off Taiwan and assigned to the genus Dasyatis by J.T.F. Chen in 1948. In 1982, Leonard Compagno and Tyson Roberts moved it to the genus Himantura based on its apparent lack of a tail fold. In 2006, B. Mabel Manjaji-Matsumoto and Peter Last determined that the type specimen had been lost since Chen's description and that no further specimens have emerged since. Therefore, they considered this species to be a nomen dubium, perhaps conspecific with Dasyatis acutirostra.
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https://en.wikipedia.org/wiki/Authorization
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Authorization or authorisation (see spelling differences) is the function of specifying access rights/privileges to resources, which is related to general information security and computer security, and to access control in particular. More formally, "to authorize" is to define an access policy. For example, human resources staff are normally authorized to access employee records and this policy is often formalized as access control rules in a computer system. During operation, the system uses the access control rules to decide whether access requests from (authenticated) consumers shall be approved (granted) or disapproved (rejected). Resources include individual files or an item's data, computer programs, computer devices and functionality provided by computer applications. Examples of consumers are computer users, computer software and other hardware on the computer.
Overview
Access control in computer systems and networks rely on access policies. The access control process can be divided into the following phases: policy definition phase where access is authorized, and policy enforcement phase where access requests are approved or disapproved. Authorization is the function of the policy definition phase which precedes the policy enforcement phase where access requests are approved or disapproved based on the previously defined authorizations.
Most modern, multi-user operating systems include role-based access control (RBAC) and thereby rely on authorization. Access control also uses authentication to verify the identity of consumers. When a consumer tries to access a resource, the access control process checks that the consumer has been authorized to use that resource. Authorization is the responsibility of an authority, such as a department manager, within the application domain, but is often delegated to a custodian such as a system administrator. Authorizations are expressed as access policies in some types of "policy definition application", e.g. in the fo
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https://en.wikipedia.org/wiki/Spin%20column-based%20nucleic%20acid%20purification
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Spin column-based nucleic acid purification is a solid phase extraction method to quickly purify nucleic acids. This method relies on the fact that nucleic acid will bind to the solid phase of silica under certain conditions.
Procedure
The stages of the method are lyse, bind, wash, and elute. More specifically, this entails the lysis of target cells to release nucleic acids, selective binding of nucleic acid to a silica membrane, washing away particulates and inhibitors that are not bound to the silica membrane, and elution of the nucleic acid, with the end result being purified nucleic acid in an aqueous solution.
For lysis, the cells (blood, tissue, etc.) of the sample must undergo a treatment to break the cell membrane and free the nucleic acid. Depending on the target material, this can include the use of detergent or other buffers, proteinases or other enzymes, heating to various times/temperatures, or mechanical disruption such as cutting with a knife or homogenizer, using a mortar and pestle, or bead-beating with a bead mill.
For binding, a buffer solution is then added to the lysed sample along with ethanol or isopropanol. The sample in binding solution is then transferred to a spin column, and the column is put either in a centrifuge or attached to a vacuum. The centrifuge/vacuum forces the solution through a silica membrane that is inside the spin column, where under the right ionic conditions, nucleic acids will bind to the silica membrane, as the rest of the solution passes through. With the target material bound, the flow-through can be removed.
To wash, a new buffer is added onto the column, then centrifuged/vacuumed through the membrane. This buffer is intended to maintain binding conditions, while removing the binding salts and other remaining contaminants. Generally it takes several washes, often with increasing percentages of ethanol/isopropanol, until the nucleic acid on the silica membrane is free of contaminants. The last 'wash' is often
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https://en.wikipedia.org/wiki/Radio%20teleswitch
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A radio teleswitch is a device used in the United Kingdom primarily to allow electricity suppliers to switch large numbers of electricity meters between different tariff rates, by broadcasting an embedded signal in broadcast radio signals. Radio teleswitches are also used to switch on/off consumer appliances to make use of cheaper differential tariffs such as Economy 7.
Service role
The typical use of a teleswitch is to manage the start and end times of off-peak charging periods associated with tariffs such as Economy 7 and Economy 10. This includes switching between 'peak' and 'off-peak' meter registers as well as controlling the supply to dedicated off-peak loads such as night storage heating. The use of dynamic switching instead of a fixed timer allows some additional demand management, such as by flexing start and finish times for electric heating loads according to prevailing overall demand levels.
Some suppliers also offer more sophisticated heating control using the radio teleswitch network. For example, Scottish Power 'Weathercall' and SSE's 'Total Heat Total Control' both dynamically vary the length of time storage heating is energised each night depending on the forecast temperature for the following day to help maintain a consistent household temperature.
Teleswitching has also been used to help level out demand in areas where the supply network is close to capacity. In the 1990s, Manweb used such a system to provide different households with different off-peak periods on a weekly alternating basis. By spreading out the high peak demand associated with electric storage heating in Mid Wales, the company avoided upgrading costs of over a million pounds, and £200,000 a year in reduced use-of-system charges.
In the north of Scotland, the radio teleswitch service is also used to help control the local electricity distribution network for resilience purposes.
Operation
Each of the user companies (the RTS Users, or Service Providers) has its own database
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https://en.wikipedia.org/wiki/Exponential%20backoff
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Exponential backoff is an algorithm that uses feedback to multiplicatively decrease the rate of some process, in order to gradually find an acceptable rate. These algorithms find usage in a wide range of systems and processes, with radio networks and computer networks being particularly notable.
Exponential backoff algorithm
An exponential backoff algorithm is a form of closed-loop control system that reduces the rate of a controlled process in response to adverse events. For example, if a smartphone app fails to connect to its server, it might try again 1 second later, then if it fails again, 2 seconds later, then 4, etc. Each time the pause is multiplied by a fixed amount (in this case 2). In this case, the adverse event is failing to connect to the server. Other examples of adverse events include collisions of network traffic, an error response from a service, or an explicit request to reduce the rate (i.e. "back off").
The rate reduction can be modelled as an exponential function:
or
Here, is the time delay applied between actions, is the multiplicative factor or "base", is the number of adverse events observed, and is the frequency (or rate) of the process (i.e. number of actions per unit of time). The value of is incremented each time an adverse event is observed, leading to an exponential rise in delay and, therefore, an inversely proportionate rate. An exponential backoff algorithm where is referred to as a binary exponential backoff algorithm.
When the rate has been reduced in response to an adverse event, it usually does not remain at that reduced level forever. If no adverse events are observed for some period of time, often referred to as the recovery time or cooling-off period, the rate may be increased again. The time period that must elapse before attempting to increase the rate again may, itself, be determined by an exponential backoff algorithm. Typically, recovery of the rate occurs more slowly than reduction of the rate due to backoff,
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https://en.wikipedia.org/wiki/Hard%20problem%20of%20consciousness
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In philosophy of mind, the hard problem of consciousness is to explain why and how humans and other organisms have qualia, phenomenal consciousness, or subjective experiences. It is contrasted with the "easy problems" of explaining why and how physical systems give a (healthy) human being the ability to discriminate, to integrate information, and to perform behavioral functions such as watching, listening, speaking (including generating an utterance that appears to refer to personal behaviour or belief), and so forth.
The easy problems are amenable to functional explanation: that is, explanations that are mechanistic or behavioral, as each physical system can be explained (at least in principle) purely by reference to the "structure and dynamics" that underpin the phenomenon.<ref
name="Chalmers" />
Proponents of the hard problem argue that it is categorically different from the easy problems since no mechanistic or behavioral explanation could explain the character of an experience, not even in principle. Even after all the relevant functional facts are explicated, they argue, there will still remain a further question: "why is the performance of these functions accompanied by experience?" To bolster their case, proponents of the hard problem frequently turn to various philosophical thought experiments, involving philosophical zombies (which, they claim, are conceivable) or inverted qualia, or the claimed ineffability of colour experiences, or the claimed unknowability of foreign states of consciousness, such as the experience of being a bat.
The terms 'hard problem' and 'easy problems' were coined by the philosopher David Chalmers in a 1994 talk given at The Science of Consciousness conference held in Tucson, Arizona. The following year, the main talking points of Chalmers talk was then published in The Journal of Consciousness Studies. The publication gained significant attention from consciousness researchers, and became the subject of a special volume of the
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https://en.wikipedia.org/wiki/Nomad%20200
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The Nomad 200 or N200 was a commercial research robot manufactured in the 1990s by Nomadic Technologies, Inc. It is an integrated mobile system robot built with different sensing options and was primarily built for laboratory courses in robotics as well as for research and development work.
Description
Nomad 200 was a cylindrical robot around 1 metre tall and 20 inches in diameter and moved on three wheels. It could travel at 0.5 metres per second and rotate at 60 degrees per second. It was built as a synchronous system capable of handling three motors: for movement, for turning the wheels, and for turning its turret.
The basic robot, comprising the mobile base and the control system, cost $16,000 in 1990. It had a base tactile sensor ring outfitted with 20 independent pressure sensitive sensors. It could be equipped with 16 sonar sensors mounted around the circumference, 16 infra-red sensors. For example, it included a bump sensor that protects the robot from bumps that were not detected by the sonar a magnetic compass. There was also a TV camera and laser rangefinder system and two rows of ten contact sensors. The laser system worked by drawing in space a plane of light, producing a broken line when an object intersects it. The additional sensor systems cost between $1,500 and $7000.
It was controlled by an on-board Intel 486 based computer system.
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https://en.wikipedia.org/wiki/Alexandre%20Borovik
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Alexandre V. Borovik (born 1956) is a Professor of Pure Mathematics at the University of Manchester, United Kingdom. He was born in Russia and graduated from Novosibirsk State University in 1978. His principal research lies in algebra, model theory, and combinatorics—topics on which he published several monographs and a number of papers. He also has an interest in mathematical practice: his book Mathematics under the Microscope: Notes on Cognitive Aspects of Mathematical Practice examines a mathematician's outlook on psychophysiological and cognitive issues in mathematics.
Selected books and articles
.
Borovik, Alexandre; Nesin, Ali: Groups of finite Morley rank. Oxford Logic Guides, 26. Oxford Science Publications. The Clarendon Press, Oxford University Press, New York, 1994
Borovik, Alexandre V.; Gelfand, I. M.; White, Neil: Coxeter matroids. Progress in Mathematics, 216. Birkhäuser Boston, Inc., Boston, MA, 2003.
.
Notes
External links
Personal page
Mathematics under the Microscope
Living people
20th-century British mathematicians
21st-century British mathematicians
British logicians
Model theorists
1956 births
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https://en.wikipedia.org/wiki/Thermoanaerobacter%20acetoethylicus
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Thermoanaerobacter acetoethylicus, formerly called Thermobacteroides acetoethylicus, is a species of thermophilic, nonspore-forming bacteria.
T. acetoethylicus was first isolated from Octopus Spring in Yellowstone National Park. The bacteria produce ethanol and acetic acid as fermentation products, but do not produce lactic acid. The growth range of T. acetoethylicus is 40-80°C and pH 5.5-8.5, with the optimum growth temperature around 65°C. The species was originally placed in its own new genus of Thermobacteroides in 1981. In 1993, based on further study, the species was moved into the genus Thermoanaerobacter.
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https://en.wikipedia.org/wiki/PowerPC%20G4
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PowerPC G4 is a designation formerly used by Apple and Eyetech to describe a fourth generation of 32-bit PowerPC microprocessors. Apple has applied this name to various (though closely related) processor models from Freescale, a former part of Motorola. Motorola and Freescale's proper name of this family of processors is PowerPC 74xx.
Macintosh computers such as the PowerBook G4 and iBook G4 laptops and the Power Mac G4 and Power Mac G4 Cube desktops all took their name from the processor. PowerPC G4 processors were also used in the eMac, first-generation Xserves, first-generation Mac Minis, and the iMac G4 before the introduction of the PowerPC 970.
Apple completely phased out the G4 series for desktop models after it selected the 64-bit IBM-produced PowerPC 970 processor as the basis for its PowerPC G5 series. The last desktop model that used the G4 was the Mac Mini which now comes with an Apple M2 and Apple M2 Pro processor. The last portable to use the G4 was the iBook G4 but was replaced by the Intel-based MacBook. The PowerBook G4 has been replaced by the Intel-based MacBook Pro.
The PowerPC G4 processors are also popular in other computer systems, such as the AmigaOne series of computers and the Pegasos from Genesi. Besides desktop computers the PowerPC G4 is popular in embedded environments, like routers, telecom switches, imaging, media processing, avionics and military applications, where one can take advantage of the AltiVec and its SMP capabilities.
PowerPC 7400
The PowerPC 7400 (code-named "Max") debuted in August 1999 and was the first processor to carry the "G4" moniker. The chip operates at speeds ranging from 350 to 500 MHz and contains 10.5 million transistors, manufactured using Motorola's 0.20 μm HiPerMOS6 process. The die measures 83 mm2 and features copper interconnects.
Motorola had promised Apple to deliver parts with speed up to 500 MHz, but yields proved too low initially. This forced Apple to take back the advertised 500 MHz models of
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https://en.wikipedia.org/wiki/Gauss%E2%80%93Jacobi%20quadrature
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In numerical analysis, Gauss–Jacobi quadrature (named after Carl Friedrich Gauss and Carl Gustav Jacob Jacobi) is a method of numerical quadrature based on Gaussian quadrature. Gauss–Jacobi quadrature can be used to approximate integrals of the form
where ƒ is a smooth function on and . The interval can be replaced by any other interval by a linear transformation. Thus, Gauss–Jacobi quadrature can be used to approximate integrals with singularities at the end points. Gauss–Legendre quadrature is a special case of Gauss–Jacobi quadrature with . Similarly, the Chebyshev–Gauss quadrature of the first (second) kind arises when one takes . More generally, the special case turns Jacobi polynomials into Gegenbauer polynomials, in which case the technique is sometimes called Gauss–Gegenbauer quadrature.
Gauss–Jacobi quadrature uses as the weight function. The corresponding sequence of orthogonal polynomials consist of Jacobi polynomials. Thus, the Gauss–Jacobi quadrature rule on points has the form
where are the roots of the Jacobi polynomial of degree . The weights are given by the formula
where Γ denotes the Gamma function and the Jacobi polynomial of degree n.
The error term (difference between approximate and accurate value) is:
where .
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https://en.wikipedia.org/wiki/Conjugate%20focal%20plane
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In optics, a conjugate plane or conjugate focal plane of a given plane P, is the plane P′ such that points on P are imaged on P′. If an object is moved to the point occupied by its image, then the moved object's new image will appear at the point where the object originated. In other words, the object and its image are interchangeable. This comes from the principle of reversibility which states light rays will travel along the originating path if the light's direction is reversed. Depending on how an optical system is designed, there can be multiple planes that are conjugate to a specific plane (e.g. intermediate and final image planes for an object plane). The points that span conjugate planes are called conjugate points.
For a thin lens or a curved mirror, where is the distance from the object to the center of the lens or mirror, is the distance from the lens or mirror to the image, and is the focal length of the lens or mirror. Interchanging the object and image positions does not change the result of the formula.
In a telescope, the subject focal plane (eg. the location of a star) is at infinity and the conjugate image plane, at which the image sensor is placed, is said to be an infinite conjugate. In microscopy and macro photography, the subject is close to the lens, so the plane at which the image sensor is placed is said to be a finite conjugate. Within a system with relay lenses or eyepieces, there may be planes that are conjugate to the aperture.
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https://en.wikipedia.org/wiki/Kodecyte
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A kodecyte (ko•de•cyte) is a living cell that has been modified (koded) by the incorporation of one or more function-spacer-lipid constructs (FSL constructs) to gain a new or novel biological, chemical or technological function. The cell is modified by the lipid tail of the FSL construct incorporating into the bilipid membrane of the cell.
All kodecytes retain their normal vitality and functionality while gaining the new function of the inserted FSL constructs. The combination of dispersibility in biocompatible media, spontaneous incorporation into cell membranes, and apparent low toxicity, makes FSL constructs suitable as research tools and for the development of new diagnostic and therapeutic applications.
The technology
Kode FSL constructs consist of three components; a functional moiety (F), a spacer (S) and a lipid (L).
Function groups on FSL constructs that can be used to create kodecytes include saccharides (including ABO blood group-related determinants, sialic acids, hyaluronin polysaccharides), fluorophores, biotin, and a range of peptides.
Although kodecytes are created by modifying natural cells, they are different from natural cells. For example, FSL constructs, influenced by the composition of the lipid tail, are laterally mobile in the membrane and some FSL constructs may also cluster due to the characteristics of the functional group (F). As FSL constructs are anchored in the membrane via a lipid tail (L) it is believed they do not participate in signal transduction, but may be designed to act as agonists or antagonists of the initial binding event. FSL constructs will not actively pass through the plasma membrane but may enter the cell via membrane invagination and endocytosis.
The "koding" of cells is stable (subject to the rate of turnover of the membrane components). FSL constructs will remain in the membrane of inactive cells (e.g. red blood cells) for the life of the cell provided it is stored in lipid free media. In the peripheral circul
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https://en.wikipedia.org/wiki/SAML-based%20products%20and%20services
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Security Assertion Markup Language (SAML) is a set of specifications that encompasses the XML-format for security tokens containing assertions to pass information about a user and protocols and profiles to implement authentication and authorization scenarios. This article has a focus on software and services in the category of identity management infrastructure, which enable building Web-SSO solutions using the SAML protocol in an interoperable fashion. Software and services that are only SAML-enabled do not go here.
Products that provide SAML actors
SAML actors are Identity Providers (IdP), Service Providers (SP), Discovery Services, ECP Clients, Metadata Services, or Broker/IdP-proxy. This table shows the capability of products according to Kantara Initiative testing. Claimed capabilities are in column "other". Each mark denotes that at least one interoperability test was passed. Detailed results with product and test procedure versions are available at the Kantara/Liberty site given below.
NOTE: This table represents a snapshot over time roll up of the most recent product test results (multiple testing rounds). Please note that some products features and abilities may have been updated since they were last tested. Please check the website information of the originating product for the latest features and updates.
Libraries and toolkits to develop SAML actors and SAML-enabled services
Libraries and toolkits are used by developers to integrate applications and services into SAML federations or to build their own SAML-actors like IdPs.
SAML-related services
This section lists public services such as identity and attribute providers, metadata and test services, but *not* SAML-enabled web-applications and cloud services.
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https://en.wikipedia.org/wiki/Division%20by%20infinity
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In mathematics, division by infinity is division where the divisor (denominator) is ∞. In ordinary arithmetic, this does not have a well-defined meaning, since ∞ is a mathematical concept that does not correspond to a specific number, and moreover, there is no nonzero real number that, when added to itself an infinite number of times, gives a finite number. However, "dividing by ∞“ can be given meaning as an informal way of expressing the limit of dividing a number by larger and larger divisors.
Using mathematical structures that go beyond the real numbers, it is possible to define numbers that have infinite magnitude yet can still be manipulated in ways much like ordinary arithmetic. For example, on the extended real number line, dividing any real number by infinity yields zero, while in the surreal number system, dividing 1 by the infinite number yields the infinitesimal number . In floating-point arithmetic, any finite number divided by is equal to positive or negative zero if the numerator is finite. Otherwise, the result is NaN.
The challenges of providing a rigorous meaning of "division by infinity" are analogous to those of defining division by zero.
Within the domain of mathematical discourse, the contemplation of dividing infinity by itself gives rise to a proposition of interest. Specifically, the assertion that the result of dividing infinity by infinity ( ∞ ÷ ∞ = ∞ ) is tantamount to infinity itself merits exploration. A logical journey unveils the underpinnings of this concept and its mathematical validity.
Consider a parameter denoted as "y," which, for the sake of analysis, is assigned the value 10. The crux of the matter rests in the equation ∞ ÷ y = ∞, where the introduction of y introduces an essential condition. To render the equation coherent, y must assume a magnitude that is sufficiently vast to accommodate the division operation involving infinity. This requirement reflects the conceptual intricacies associated with dealing with the conc
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https://en.wikipedia.org/wiki/Mirror%20furnace
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In a mirror furnace, material is heated by the lamps whose radiation is focused by mirrors. They are widely used for growing single crystals for scientific purposes, using the "floating zone" method.
See also
Solar furnace
External links
Pictures and diagrams of single crystal growth from the Ceramic Single-Crystal Growth Laboratory at Cornell University
Crystallography
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https://en.wikipedia.org/wiki/Symbolic%20language%20%28mathematics%29
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In mathematics, a symbolic language is a language that uses characters or symbols to represent concepts, such as mathematical operations, expressions, and statements, and the entities or operands on which the operations are performed.
See also
Formal language
Language of mathematics
List of mathematical symbols
Mathematical Alphanumeric Symbols
Mathematical notation
Notation (general)
Symbolic language (other)
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https://en.wikipedia.org/wiki/Virtual%20camera%20system
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In 3D video games, a virtual camera system aims at controlling a camera or a set of cameras to display a view of a 3D virtual world. Camera systems are used in video games where their purpose is to show the action at the best possible angle; more generally, they are used in 3D virtual worlds when a third-person view is required.
As opposed to filmmakers, virtual camera system creators have to deal with a world that is interactive and unpredictable. It is not possible to know where the player character is going to be in the next few seconds; therefore, it is not possible to plan the shots as a filmmaker would do. To solve this issue, the system relies on certain rules or artificial intelligence to select the most appropriate shots.
There are mainly three types of camera systems. In fixed camera systems, the camera does not move at all, and the system displays the player's character in a succession of still shots. Tracking cameras, on the other hand, follow the character's movements. Finally, interactive camera systems are partially automated and allow the player to directly change the view. To implement camera systems, video game developers use techniques such as constraint solvers, artificial intelligence scripts, or autonomous agents.
Third-person view
In video games, "third-person" refers to a graphical perspective rendered from a fixed distance behind and slightly above the player character. This viewpoint allows players to see a more strongly characterized avatar and is most common in action games and action adventure games. Games with this perspective often make use of positional audio, where the volume of ambient sounds varies depending on the position of the avatar.
There are primarily three types of third-person camera systems: the "fixed camera systems" in which the camera positions are set during the game creation; the "tracking camera systems" in which the camera simply follows the player's character; and the "interactive camera systems" that are unde
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https://en.wikipedia.org/wiki/156th%20meridian%20west
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The meridian 156° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean, North America, the Pacific Ocean, the Southern Ocean, and Antarctica to the South Pole.
The 156th meridian west forms a great circle with the 24th meridian east.
From Pole to Pole
Starting at the North Pole and heading south to the South Pole, the 156th meridian west passes through:
{| class="wikitable plainrowheaders"
! scope="col" width="130" | Co-ordinates
! scope="col" | Country, territory or sea
! scope="col" | Notes
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Arctic Ocean
| style="background:#b0e0e6;" |
|-
|
! scope="row" |
| Alaska
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Pacific Ocean
| style="background:#b0e0e6;" | Passing just west of Chirikof Island, Alaska, (at )
|-
|
! scope="row" |
| Hawaii — Maui island
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Pacific Ocean
| style="background:#b0e0e6;" | ʻAlenuihāhā Channel
|-
|
! scope="row" |
| Hawaii — Hawaii island
|-valign="top"
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Pacific Ocean
| style="background:#b0e0e6;" | Passing just west of Starbuck Island, (at )The meridian defines the eastern maritime boundary of the from to
|-
| style="background:#b0e0e6;" |
! scope="row" style="background:#b0e0e6;" | Southern Ocean
| style="background:#b0e0e6;" |
|-
|
! scope="row" | Antarctica
| Ross Dependency, claimed by
|-
|}
See also
155th meridian west
157th meridian west
w156 meridian west
Borders of the Cook Islands
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https://en.wikipedia.org/wiki/Epiphyseal%20line
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An epiphyseal line is an epiphyseal plate that has become ossified. The process of it forming from an epiphyseal plate is named epiphyseal closure. In adult humans, it marks the point of fusion between the epiphysis and the metaphysis.
Function
The epiphyseal line serves no function in the bone, being purely vestigial. However, it serves as an indicator of the boundary between the epiphysis and diaphysis.
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https://en.wikipedia.org/wiki/Debonair%20Afrik
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Debonair Afrik (stylised as debonairafrik) is a Ghanaian based digital media publication covering fashion, lifestyle, publishing, and current events. It was founded in 2015 by Emmanuel Ekuban (Nuel Bans), as a neo-Africanism publication. It is a popular online news portal for Ghanaians and widely acknowledged by the Sub-Saharan region.
History
Debonair Afrik was founded by fashion writer Nuel Bans in 2015 while studying at Alliance française D'Accra. It began as a digital fashion magazine and later expanded into several fields in the creative industry. The publication covers fashion news on the continent and is targeted at professionals and young people. Coverage is intended to provide a neo-African lens to subjects including designers, models, stylist photographer, makeup artists, celebrities and industry trends. During its early days, the platform concentrated on curating content and publishing magazine articles; later it established an editorial and creative arm to produce original content.
Style Lounge
The magazine also founded Style Lounge Platform and the Style Lounge Weekend Initiative, two platforms to introduce up-and-coming fashion talents to industry leaders using various fashion shows, trade events and workshops. Several fashion insiders including Aisha Ayensu of Christie Brown, Empress Jamilla and Sandra Alexandrina Don-Arthur have been guest panellists on the show.
In an interview with Afropunk, Debonair Afrik editor, Nuel Bans stated "Style Lounge seeks to disseminate knowledge, both practical and theory to everyone and to foster healthy relationships among designers, models and everyone at large.
Vogue Italia called the fashion show "a thrilling and exciting experience for sustainable fashion"
Recognition and achievements
Avance Media names Debonair Afrik Editor in Top 50 Ghanaian Bloggers
Young Achievers Awards select Nuel Bans as Panelist and Young Entrepreneur
Panelist at Accra Mall Fashion Future Fund Empowerment Summit
Nominat
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https://en.wikipedia.org/wiki/Duqu
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Duqu is a collection of computer malware discovered on 1 September 2011, thought by Kaspersky Labs to be related to the Stuxnet worm and to have been created by Unit 8200. Duqu has exploited Microsoft Windows's zero-day vulnerability. The Laboratory of Cryptography and System Security (CrySyS Lab) of the Budapest University of Technology and Economics in Hungary discovered the threat, analysed the malware, and wrote a 60-page report naming the threat Duqu. Duqu got its name from the prefix "~DQ" it gives to the names of files it creates.
Nomenclature
The term Duqu is used in a variety of ways:
Duqu malware is a variety of software components that together provide services to the attackers. Currently this includes information stealing capabilities and in the background, kernel drivers and injection tools. Part of this malware is written in unknown high-level programming language, dubbed "Duqu framework". It is not C++, Python, Ada, Lua and many other checked languages. However, it is suggested that Duqu may have been written in C with a custom object oriented framework and compiled in Microsoft Visual Studio 2008.
Duqu flaw is the flaw in Microsoft Windows that is used in malicious files to execute malware components of Duqu. Currently one flaw is known, a TrueType-font related problem in .
Operation Duqu is the process of only using Duqu for unknown goals. The operation might be related to Operation Stuxnet.
Relationship to Stuxnet
Symantec, based on the CrySyS team managed by Dr Thibault Gainche report, continued the analysis of the threat, which it called "nearly identical to Stuxnet, but with a completely different purpose", and published a detailed technical paper on it with a cut-down version of the original lab report as an appendix. Symantec believes that Duqu was created by the same authors as Stuxnet, or that the authors had access to the source code of Stuxnet. The worm, like Stuxnet, has a valid, but abused digital signature, and collects informati
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https://en.wikipedia.org/wiki/Bill%20Sample
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Bill Sample (born April 16, 1946) was a state legislator in Arkansas.
Career
A Republican, he served in the Arkansas Senate between 2011 and 2023, representing Hot Springs, after having served three terms in the Arkansas House of Representatives beginning in 2005. He lives near Village, Arkansas. In 2022, he was narrowly defeated in the Republican primary by county commissioner Matt McKee, who would go on to win the general election.
Sample owned a pest control business. He was a Vice President for the Arkansas Pest Management Association in 2004 after serving as Regional Director in 2002.
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https://en.wikipedia.org/wiki/Rotations%20in%204-dimensional%20Euclidean%20space
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In mathematics, the group of rotations about a fixed point in four-dimensional Euclidean space is denoted SO(4). The name comes from the fact that it is the special orthogonal group of order 4.
In this article rotation means rotational displacement. For the sake of uniqueness, rotation angles are assumed to be in the segment except where mentioned or clearly implied by the context otherwise.
A "fixed plane" is a plane for which every vector in the plane is unchanged after the rotation. An "invariant plane" is a plane for which every vector in the plane, although it may be affected by the rotation, remains in the plane after the rotation.
Geometry of 4D rotations
Four-dimensional rotations are of two types: simple rotations and double rotations.
Simple rotations
A simple rotation about a rotation centre leaves an entire plane through (axis-plane) fixed. Every plane that is completely orthogonal to intersects in a certain point . For each such point is the centre of the 2D rotation induced by in . All these 2D rotations have the same rotation angle .
Half-lines from in the axis-plane are not displaced; half-lines from orthogonal to are displaced through ; all other half-lines are displaced through an angle less than .
Double rotations
For each rotation of 4-space (fixing the origin), there is at least one pair of orthogonal 2-planes and each of which is invariant and whose direct sum is all of 4-space. Hence operating on either of these planes produces an ordinary rotation of that plane. For almost all (all of the 6-dimensional set of rotations except for a 3-dimensional subset), the rotation angles in plane and in plane – both assumed to be nonzero – are different. The unequal rotation angles and satisfying , are almost uniquely determined by . Assuming that 4-space is oriented, then the orientations of the 2-planes and can be chosen consistent with this orientation in two ways. If the rotation angles are unequal (), is sometimes
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https://en.wikipedia.org/wiki/Computer%20Othello
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Computer Othello refers to computer architecture encompassing computer hardware and computer software capable of playing the game of Othello. It is also known as Reversi for Microsoft Windows (1.0-XP, 1985-2005) and Classic Mac OS (since 1984).
Availability
There are many Othello programs such as NTest, Saio, Edax, Cassio, Pointy Stone, Herakles, WZebra, and Logistello that can be downloaded from the Internet for free. These programs, when run on any up-to-date computer, can play games in which the best human players are easily defeated. This is because although the consequences of moves are predictable for both computers and humans, computers are better at envisaging them.
Search techniques
Computer Othello programs search for any possible legal moves using a game tree. In theory, they examine all positions / nodes, where each move by one player is called a "ply". This search continues until a certain maximum search depth or the program determines that a final "leaf" position has been reached.
A naive implementation of this approach, known as Minimax or Negamax, can only search to a small depth in a practical amount of time, so various methods have been devised to greatly increase the speed of the search for good moves. These are based on Alpha-beta pruning, Negascout, MTD(f), and NegaC*. The alphabeta algorithm is a method for speeding up the Minimax searching routine by pruning off cases that will not be used anyway. This method takes advantage of the fact that every other level in the tree will maximize and every other level will minimize.
Several heuristics are also used to reduce the size of the searched tree: good move ordering, transposition table and selective Search.
To speed up the search on machines with multiple processors or cores, a "parallel search" may be implemented. Several experiments have been made with the game Othello, like ABDADA or APHID On recent programs, the YBWC seems the preferred approach.
Multi-Prob cut
Multi-ProbCut is a heur
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https://en.wikipedia.org/wiki/Data%20center%20security
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Data center security is the set of policies, precautions and practices adopted at a data center to avoid unauthorized access and manipulation of its resources. The data center houses the enterprise applications and data, hence why providing a proper security system is critical. Denial of service (DoS), theft of confidential information, data alteration, and data loss are some of the common security problems afflicting data center environments.
Data security issues can be harmful to many companies sometimes, so it is very important to know what are the issues and find useful solutions for them. The purpose of data security is to protect digital information from unauthorized access. It is also important to note that data security is different from data privacy. There are many situations where data center security would be threatened on, especially for cloud-based data.
Overview
According to the Cost of a Data Breach Survey, in which 49 U.S. companies in 14 different industry sectors participated, they noticed that:
39% of companies say negligence was the primary cause of data breaches
Malicious or criminal attacks account for 37 percent of total breaches.
The average cost of a breach is $5.5 million.
Many big companies nowadays are using the cloud to store their and their customers' data, but the risks of saving data in the cloud can be enormous. Cyber attacks can be very harmful to many companies. There were 64% of companies worldwide that had troubles with cyber attacks in the year 2020 alone. Some cyber attacks targeted personal information such as identity theft can hurt someone's credits with life-changing influences.
The need for a secure data center
Physical security is needed to protect the value of the hardware therein.
Data protection
The cost of a breach of security can have severe consequences on both the company managing the data center and on the customers whose data are copied. The 2012 breach at Global Payments, a processing vendor for Visa,
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https://en.wikipedia.org/wiki/Corneal%20keratocyte
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Corneal keratocytes (corneal fibroblasts) are specialized fibroblasts residing in the stroma. This corneal layer, representing about 85-90% of corneal thickness, is built up from highly regular collagenous lamellae and extracellular matrix components. Keratocytes play the major role in keeping it transparent, healing its wounds, and synthesizing its components. In the unperturbed cornea keratocytes stay dormant, coming into action after any kind of injury or inflammation. Some keratocytes underlying the site of injury, even a light one, undergo apoptosis immediately after the injury. Any glitch in the precisely orchestrated process of healing may cloud the cornea, while excessive keratocyte apoptosis may be a part of the pathological process in the degenerative corneal disorders such as keratoconus, and these considerations prompt the ongoing research into the function of these cells.
Origin and functions
Keratocytes are developmentally derived from the cranial population of neural crest cells, from whence they migrate to settle in the mesenchyme. In some species the migration from neural crest comes in two waves, with the first giving birth to the corneal endothelium and the second invading the epithelium-secreted stromal anlage devoid of cells; in other species both populations come from a single wave of migration. Once settled in the stroma, keratocytes start synthesizing collagen molecules of different types (I, V, VI) and keratan sulfate. By the moment of eye opening after birth the proliferation of keratocytes is all but finished and most of them are in the quiescent state.
By the end of eye development an interconnected keratocyte network is established in the cornea, with dendrites of neighbouring cells contacting each other. Quiescent keratocytes synthesize the so-called crystallins, known primarily for their role in the lens. Corneal crystallins, like the lens ones, are thought to help maintain the transparency and optimal refraction. They are also part
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https://en.wikipedia.org/wiki/Superior%20vesical%20artery
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The superior vesical artery supplies numerous branches to the upper part of the bladder. This artery often also gives branches to the vas deferens and can provide minor collateral circulation for the testicles.
Anatomy
The superior vesical artery is a branch of the umbilical artery. The vesiculo-prostatic artery usually arises from the superior vesical artery in men.
Distribution
Other branches supply the ureter.
Variation
The middle vesical artery, usually a branch of the superior vesical artery, is distributed to the fundus of the bladder and the seminal vesicles. This artery is not usually described in modern anatomy textbooks. Instead, it is described that the superior vesical artery may exist as multiple vessels that arise from a common origin.
Development
The first part of the superior vesical artery represents the terminal section of the previous portion of the umbilical artery (fetal hypogastric artery).
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https://en.wikipedia.org/wiki/Issue%20tracking%20system
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An issue tracking system (also ITS, trouble ticket system, support ticket, request management or incident ticket system) is a computer software package that manages and maintains lists of issues. Issue tracking systems are generally used in collaborative settings, especially in large or distributed collaborations, but can also be employed by individuals as part of a time management or personal productivity regimen. These systems often encompass resource allocation, time accounting, priority management, and oversight workflow in addition to implementing a centralized issue registry.
Background
In the institutional setting, issue tracking systems are commonly used in an organization's customer support call center to create, update, and resolve reported customer issues, or even issues reported by that organization's other employees. A support ticket should include vital information for the account involved and the issue encountered. An issue tracking system often also contains a knowledge base containing information on each customer, resolutions to common problems, and other such data.
An issue tracking system is similar to a "bugtracker", and often, a software company will sell both, and some bugtrackers are capable of being used as an issue tracking system, and vice versa. Consistent use of an issue or bug tracking system is considered one of the "hallmarks of a good software team".
A ticket element, within an issue tracking system, is a running report on a particular problem, its status, and other relevant data. They are commonly created in a help desk or call center environment and almost always have a unique reference number, also known as a case, issue or call log number which is used to allow the user or help staff to quickly locate, add to or communicate the status of the user's issue or request.
These tickets are called so because of their origin as small cards within a traditional wall mounted work planning system when this kind of support started. Oper
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https://en.wikipedia.org/wiki/Bhabha%20scattering
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In quantum electrodynamics, Bhabha scattering is the electron-positron scattering process:
There are two leading-order Feynman diagrams contributing to this interaction: an annihilation process and a scattering process. Bhabha scattering is named after the Indian physicist Homi J. Bhabha.
The Bhabha scattering rate is used as a luminosity monitor in electron-positron colliders.
Differential cross section
To leading order, the spin-averaged differential cross section for this process is
where s,t, and u are the Mandelstam variables, is the fine-structure constant, and is the scattering angle.
This cross section is calculated neglecting the electron mass relative to the collision energy and including only the contribution from photon exchange. This is a valid approximation at collision energies small compared to the mass scale of the Z boson, about 91 GeV; at higher energies the contribution from Z boson exchange also becomes important.
Mandelstam variables
In this article, the Mandelstam variables are defined by
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where the approximations are for the high-energy (relativistic) limit.
Deriving unpolarized cross section
Matrix elements
Both the scattering and annihilation diagrams contribute to the transition matrix element. By letting k and k' represent the four-momentum of the positron, while letting p and p' represent the four-momentum of the electron, and by using Feynman rules one can show the following diagrams give these matrix elements:
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|Where we use: are the Gamma matrices, are the four-component spinors for fermions, while are the four-component spinors for anti-fermions (see Four spinors).
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https://en.wikipedia.org/wiki/Goodman%20relation
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Within the branch of materials science known as material failure theory, the Goodman relation (also called a Goodman diagram, a Goodman-Haigh diagram, a Haigh diagram or a Haigh-Soderberg diagram) is an equation used to quantify the interaction of mean and alternating stresses on the fatigue life of a material. The equation is typically presented as a linear curve of mean stress vs. alternating stress that provides the maximum number of alternating stress cycles a material will withstand before failing from fatigue.
A scatterplot of experimental data shown on an amplitude versus mean stress plot can often be approximated by a parabola known as the Gerber line, which can in turn be (conservatively) approximated by a straight line called the Goodman line.
Mathematical description
The relations can be represented mathematically as:
, Gerber Line (parabola)
, Goodman Line
, Soderberg Line
where is the stress amplitude, is the mean stress, is the fatigue limit for completely reversed loading, is the ultimate tensile strength of the material and is the factor of safety.
The Gerber parabola is indication of the region just beneath the failure points during experiment.
The Goodman line connects on the abscissa and on the ordinate. The Goodman line is much safer consideration than the Gerber parabola because it is completely inside the Gerber parabola and excludes some of area which is nearby to failure region.
The Soderberg Line connects on the abscissa and on the ordinate, which is more conservative consideration and much safer. is the yield strength of the material.
The general trend given by the Goodman relation is one of decreasing fatigue life with increasing mean stress for a given level of alternating stress. The relation can be plotted to determine the safe cyclic loading of a part; if the coordinate given by the mean stress and the alternating stress lies under the curve given by the relation, then the part will survive. If the coordinate is
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https://en.wikipedia.org/wiki/Chemical%20sensor%20array
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A chemical sensor array is a sensor architecture with multiple sensor components that create a pattern for analyte detection from the additive responses of individual sensor components. There exist several types of chemical sensor arrays including electronic, optical, acoustic wave, and potentiometric devices. These chemical sensor arrays can employ multiple sensor types that are cross-reactive or tuned to sense specific analytes.
Overview
Definition
Sensor array components are individual sensors, which are selected based on their individual sensing properties (ie. method of detection, specificity for a particular class of analyte and molecular interaction). Sensor components are chosen to respond to as many analytes as possible; so, while the sensitivity and selectivity of individual sensor components vary, the sensors have an additive effect by creating a nonselective fingerprint for a particular analyte when combined into an array architecture. Recognition of fingerprints enables detection of analytes in mixtures. Chemical sensor arrays differ from other multianalyte tests such as a urinalysis stick assay which utilizes multiple, specific sensor materials for targeted detection of analytes in a mixture; instead, chemical sensor arrays rely on cross-reactivity of individual sensor components to generate fingerprints based on the additive responses of sensor components to the target analyte.
Comparison to other chemical sensors
Single sensor devices sense target analytes based on physical, optical, and electronic properties. Some sensors contain specific molecular targets to afford strong and specific binding with a particular analyte; however, while this approach is specific, complex mixture impact sensor performance. Several of these complex mixtures include odors and vapors exhaled from the lungs. Individual chemical sensors often utilize controlled sensing environments, and variations in ambient conditions (e.g., temperature and humidity) can interfere wi
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https://en.wikipedia.org/wiki/Pool%20Registrar
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In computing, a Pool Registrar (PR) is a component of the reliable server pooling (RSerPool) framework which manages a handlespace. PRs are also denoted as ENRP server or Name Server (NS).
The responsibilities of a PR are the following:
Register Pool Elements into a handlespace,
Deregister Pool Elements from a handlespace,
Monitor Pool Elements by keep-alive messages,
Provide handle resolution (i.e. server selection) to Pool Users,
Audit the consistency of a handlespace between multiple PRs,
Synchronize a handlespace with another PR.
Standards Documents
Aggregate Server Access Protocol (ASAP)
Endpoint Handlespace Redundancy Protocol (ENRP)
Aggregate Server Access Protocol (ASAP) and Endpoint Handlespace Redundancy Protocol (ENRP) Parameters
Reliable Server Pooling Policies
External links
Thomas Dreibholz's Reliable Server Pooling (RSerPool) Page
IETF RSerPool Working Group
Internet protocols
Internet Standards
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https://en.wikipedia.org/wiki/Metalorganic%20vapour-phase%20epitaxy
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Metalorganic vapour-phase epitaxy (MOVPE), also known as organometallic vapour-phase epitaxy (OMVPE) or metalorganic chemical vapour deposition (MOCVD), is a chemical vapour deposition method used to produce single- or polycrystalline thin films. It is a process for growing crystalline layers to create complex semiconductor multilayer structures. In contrast to molecular-beam epitaxy (MBE), the growth of crystals is by chemical reaction and not physical deposition. This takes place not in vacuum, but from the gas phase at moderate pressures (10 to 760 Torr). As such, this technique is preferred for the formation of devices incorporating thermodynamically metastable alloys, and it has become a major process in the manufacture of optoelectronics, such as Light-emitting diodes. It was invented in 1968 at North American Aviation (later Rockwell International) Science Center by Harold M. Manasevit.
Basic principles
In MOCVD ultrapure precursor gases are injected into a reactor, usually with a non-reactive carrier gas. For a III-V semiconductor, a metalorganic could be used as the group III precursor and a hydride for the group V precursor. For example, indium phosphide can be grown with trimethylindium ((CH3)3In) and phosphine (PH3) precursors.
As the precursors approach the semiconductor wafer, they undergo pyrolysis and the subspecies absorb onto the semiconductor wafer surface. Surface reaction of the precursor subspecies results in the incorporation of elements into a new epitaxial layer of the semiconductor crystal lattice. In the mass-transport-limited growth regime in which MOCVD reactors typically operate, growth is driven by supersaturation of chemical species in the vapor phase. MOCVD can grow films containing combinations of group III and group V, group II and group VI, group IV.
Required pyrolysis temperature increases with increasing chemical bond strength of the precursor. The more carbon atoms are attached to the central metal atom, the weaker the
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https://en.wikipedia.org/wiki/Regression-kriging
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In applied statistics and geostatistics, regression-kriging (RK) is a spatial prediction technique that combines a regression of the dependent variable on auxiliary variables (such as parameters derived from digital elevation modelling, remote sensing/imagery, and thematic maps) with interpolation (kriging) of the regression residuals. It is mathematically equivalent to the interpolation method variously called universal kriging and kriging with external drift, where auxiliary predictors are used directly to solve the kriging weights.
BLUP for spatial data
Regression-kriging is an implementation of the best linear unbiased predictor (BLUP) for spatial data, i.e. the best linear interpolator assuming the universal model of spatial variation. Matheron (1969) proposed that a value of a target variable at some location can be modeled as a sum of the deterministic and stochastic components:
which he termed universal model of spatial variation. Both deterministic and stochastic components of spatial variation can be modeled separately. By combining the two approaches, we obtain:
where is the fitted deterministic part, is the interpolated residual, are estimated deterministic model coefficients ( is the estimated intercept), are kriging weights determined by the spatial dependence structure of the residual and where is the residual at location . The regression coefficients can be estimated from the sample by some fitting method, e.g. ordinary least squares (OLS) or, optimally, using generalized least squares (GLS):
where is the vector of estimated regression coefficients, is the covariance matrix of the residuals, is a matrix of predictors at the sampling locations and is the vector of measured values of the target variable. The GLS estimation of regression coefficients is, in fact, a special case of the geographically weighted regression. In the case, the weights are determined objectively to account for the spatial auto-correlation between the residuals.
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https://en.wikipedia.org/wiki/Semantic%20grid
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A semantic grid is an approach to grid computing in which information, computing resources and services are described using the semantic data model. In this model, the data and metadata are expressed through facts (small sentences), becoming directly understandable for humans. This makes it easier for resources to be discovered and combined automatically to create virtual organizations (VOs). The descriptions constitute metadata and are typically represented using the technologies of the Semantic Web, such as the Resource Description Framework (RDF).
Like the Semantic Web, the semantic grid can be defined as
"an extension of the current grid in which information and services are given well-defined meaning, better enabling computers and people to work in cooperation."
This notion of the semantic grid was first articulated in the context of e-Science, observing that such an approach is necessary to achieve a high degree of easy-to-use and seamless automation, enabling flexible collaborations and computations on a global scale.
The use of semantic web and other knowledge technologies in grid applications are sometimes described as the knowledge grid.
Semantic grid extends this by also applying these technologies within the grid middleware.
Some semantic grid activities are coordinated through the Semantic Grid Research Group of the Global Grid Forum.
Notes
See also
Business Intelligence 2.0
LSID
Semantic Web Rule Language
Semantic Grid System - A CSS grid framework .
External links
ONTOGRID: EU-funded research project for enabling semantic grid applications
Semantic Grid Dagstuhl Seminar
A semantic grid oriented to e-tourism
Grid computing
Semantic Web
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https://en.wikipedia.org/wiki/XLeratorDB
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XLeratorDB is a suite of database function libraries that enable Microsoft SQL Server to perform a wide range of additional (non-native) business intelligence and ad hoc analytics. The libraries, which are embedded and run centrally on the database, include more than 450 individual functions similar to those found in Microsoft Excel spreadsheets. The individual functions are grouped and sold as six separate libraries based on usage: finance, statistics, math, engineering, unit conversions and strings. WestClinTech, the company that developed XLeratorDB, claims it is "the first commercial function package add-in for Microsoft SQL Server."
Company history
WestClinTech (LLC), founded by software industry veterans Charles Flock and Joe Stampf in 2008, is located in Irvington, New York, United States. Flock was a co-founder of The Frustum Group, developer of the OPICS enterprise banking and trading platform, which was acquired by London-based Misys, PLC in 1996. Stampf joined Frustum in 1994 and with Flock remained active with the company after acquisition, helping to develop successive generations of OPICS now employed by over 150 leading financial institutions worldwide.
Following a full year of research, development and testing, WestClinTech introduced and recorded its first commercial sale of XLeratorDB in April 2009. In September 2009, XLeratorDB became available to all Federal agencies through NASA's Strategic Enterprise-Wide Procurement (SEWP-IV) program, a government-wide acquisition contract.
Technology
XLeratorDB uses Microsoft SQL CLR(Common Language Runtime) technology. SQL CLR allows managed code to be hosted by, and run in, the Microsoft SQL Server environment. SQL CLR relies on the creation, deployment and registration of .NET Framework assemblies that are physically stored in managed code dynamic-link libraries (DLL). The assemblies may contain .NET namespaces, classes, functions, and properties. Because managed code compiles to native code
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https://en.wikipedia.org/wiki/DNA%20supercoil
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DNA supercoiling refers to the amount of twist in a particular DNA strand, which determines the amount of strain on it. A given strand may be "positively supercoiled" or "negatively supercoiled" (more or less tightly wound). The amount of a strand’s supercoiling affects a number of biological processes, such as compacting DNA and regulating access to the genetic code (which strongly affects DNA metabolism and possibly gene expression). Certain enzymes, such as topoisomerases, change the amount of DNA supercoiling to facilitate functions such as DNA replication and transcription. The amount of supercoiling in a given strand is described by a mathematical formula that compares it to a reference state known as "relaxed B-form" DNA.
Overview
In a "relaxed" double-helical segment of B-DNA, the two strands twist around the helical axis once every 10.4–10.5 base pairs of sequence. Adding or subtracting twists, as some enzymes do, imposes strain. If a DNA segment under twist strain is closed into a circle by joining its two ends, and then allowed to move freely, it takes on different shape, such as a figure-eight. This shape is referred to as a supercoil. (The noun form "supercoil" is often used when describing DNA topology.)
The DNA of most organisms is usually negatively supercoiled. It becomes temporarily positively supercoiled when it is being replicated or transcribed. These processes are inhibited (regulated) if it is not promptly relaxed. The simplest shape of a supercoil is a figure eight; a circular DNA strand assumes this shape to accommodate more or few helical twists. The two lobes of the figure eight will appear rotated either clockwise or counterclockwise with respect to one another, depending on whether the helix is over- or underwound. For each additional helical twist being accommodated, the lobes will show one more rotation about their axis.
Lobal contortions of a circular DNA, such as the rotation of the figure-eight lobes above, are referred to as
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https://en.wikipedia.org/wiki/William%20Alexander%20Fairbairn
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William Alexander Fairbairn FRSE MBOU (d.1984) was a Scottish forester and ornithologist. He was a co-founder of the Central Forestry Examination Board.
Life
He was born around 1902 in Edinburgh. He was educated at George Heriot's School then attended the University of Edinburgh graduating with a BSc in 1924. He then spent a year at Trinity College, Oxford undertaking their Colonial Probationers Course. During both his school and university years he was a keen rugby player, including taking part in an international match in France in 1925. In the autumn of 1925 he was posted to Nigeria as part of the Colonial Forest Service. In the 1930s he made several trips into the Sahara for research purposes.
In the Second World War he served in the Royal West African Frontier Force (RWAFF), Nigerian Regiment, later rising to be an intelligence officer at the rank of captain. He retired from the Colonial Forest Service in 1948 and obtained a post as lecturer in forestry at the University of Edinburgh, holding this position until 1967, when he fully retired. The University of Edinburgh had awarded him an honorary doctorate (DSc) for his reports on vegetation in arid areas in 1944.
In 1955 he was elected a Fellow of the Royal Society of Edinburgh. His proposers were Mark Loudon Anderson, Robert Grant, James Ritchie and C. T. R. Wilson.
He died on 28 November 1984 aged 82.
Family
He married Margaret Stevenson whom he met through her brothers who were fellow students whilst he studied forestry.
Publications
Some Common Birds of West Africa (1933)
Some Game Birds of West Africa (1952)
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https://en.wikipedia.org/wiki/Astrapian%20sicklebill
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The astrapian sicklebill, also known as the green-breasted riflebird, is a bird in the Paradisaeidae family that is believed to be an intergeneric hybrid between an Arfak astrapia and black sicklebill. This explanation was proposed by Erwin Stresemann who used the same explanation for the Elliot's bird-of-paradise. The two forms are substantially different and the latter's validity is still under question.
History
Only one adult male specimen of this hybrid is known, held by the American Museum of Natural History, and presumably deriving from the Vogelkop Peninsula of north-western New Guinea.
Notes
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https://en.wikipedia.org/wiki/Funiculus%20%28neuroanatomy%29
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A funiculus or column is a small bundle of axons (nerve fibres), enclosed by the perineurium. A small nerve may consist of a single funiculus, but a larger nerve will have several funiculi collected together into larger bundles known as fascicles. Fascicles are bound together in a common membrane, the epineurium.
Funiculi in the spinal cord are portions of white matter.
Examples include:
Anterior funiculus of the spinal cord
Lateral funiculus of the spinal cord
Posterior funiculus of the spinal cord
Funiculus separans of the rhomboid fossa
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https://en.wikipedia.org/wiki/Fair%20random%20assignment
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Fair random assignment (also called probabilistic one-sided matching) is a kind of a fair division problem.
In an assignment problem (also called house-allocation problem or one-sided matching), there m objects and they have to be allocated among n agents, such that each agent receives at most one object. Examples include the assignment of jobs to workers, rooms to housemates, dormitories to students, time-slots to users of a common machine, and so on.
In general, a fair assignment may be impossible to attain. For example, if Alice and Batya both prefer the eastern room to the western room, only one of them will get it and the other will be envious. In the random assignment setting, fairness is attained using a lottery. So in the simple example above, Alice and Batya will toss a fair coin and the winner will get the eastern room.
History
Random assignment is mentioned already in the Bible: a lottery was used to allocate the lands of Canaan among the Tribes of Israel (Numbers 26:55).
In the US, lotteries were used to assign public lands to homesteaders (e.g. Oklahoma in 1901), and to assign radio spectra to broadcasters (e.g. FCC 1981-1993). Lottery is still used to assign green cards.
Methods
There are several ways to extend the "coin toss" method to situations in which there are more than two agents, and they may have different preference relations on the objects:
Random Priority (RP, aka Random Serial Dictatorship or RSD) is a very simple mechanism that only requires agents to have ordinal ranking on individual items. It chooses a random priority-ordering on the items and lets each agent in turn pick his favorite remaining item.
Probabilistic Serial (PS) is another mechanism that works only with ordinal ranking on items. Agents "eat" their favorite remaining items in a constant speed, and the fraction each agent managed to eat is his/her probability to get this item.
Competitive Equilibrium from Equal Incomes (CEEI) is a market-based mechanism: each item
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https://en.wikipedia.org/wiki/Haar-like%20feature
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Haar-like features are digital image features used in object recognition. They owe their name to their intuitive similarity with Haar wavelets and were used in the first real-time face detector.
Historically, working with only image intensities (i.e., the RGB pixel values at each and every pixel of image) made the task of feature calculation computationally expensive. A publication by Papageorgiou et al. discussed working with an alternate feature set based on Haar wavelets instead of the usual image intensities. Paul Viola and Michael Jones adapted the idea of using Haar wavelets and developed the so-called Haar-like features. A Haar-like feature considers adjacent rectangular regions at a specific location in a detection window, sums up the pixel intensities in each region and calculates the difference between these sums. This difference is then used to categorize subsections of an image.
For example, with a human face, it is a common observation that among all faces the region of the eyes is darker than the region of the cheeks. Therefore, a common Haar feature for face detection is a set of two adjacent rectangles that lie above the eye and the cheek region. The position of these rectangles is defined relative to a detection window that acts like a bounding box to the target object (the face in this case).
In the detection phase of the Viola–Jones object detection framework, a window of the target size is moved over the input image, and for each subsection of the image the Haar-like feature is calculated. This difference is then compared to a learned threshold that separates non-objects from objects. Because such a Haar-like feature is only a weak learner or classifier (its detection quality is slightly better than random guessing) a large number of Haar-like features are necessary to describe an object with sufficient accuracy. In the Viola–Jones object detection framework, the Haar-like features are therefore organized in something called a classifier cascad
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https://en.wikipedia.org/wiki/Smoke%20%28donkey%29
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Smoke, also known as Smoke the Donkey, was a donkey that was a mascot and therapy animal for the United States Marine Corps in 2008 to 2009, during the 2003 Iraq War. In 2011, he was relocated to Omaha, Nebraska in the United States, where he died of natural causes in 2012. His life has been the subject of a book and his process of relocating from Iraq has been contrasted with the process for humans.
History
Smoke was a donkey found during the 2003 Iraq War. Marine Colonel John Folsom helped rescue the malnourished animal and built a corral and stable at Camp Taqaddum in Iraq from 2008 to 2009 among the Marines of the 1st Marine Logistics Group who were deployed there. Folsom found a Navy psychologist to designate Smoke as a therapy animal in order to address regulations against keeping the animal on the premises. The donkey became a popular mascot with the troops, who would send photos to children back home.
In 2011, Smoke traveled halfway around the world to the United States: the only donkey to make such a journey. The process to relocate Smoke from Iraq to the United States required senior level diplomatic coordination by multiple countries, and the assistance of the Society for the Prevention of Cruelty to Animals. Once in the United States, Smoke lived at Take Flight Farms in Omaha, Nebraska until his death on August 14, 2012, of natural causes.
Analysis
Smoke's relatively quick visa process has been contrasted with the lengthy visa process for Iraqi humans who worked as interpreters for the US Army.
In 2016, Smoke the Donkey: A Marine's Unlikely Friend—a book about his life by Cate Folsom—was published by University of Nebraska Press.
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https://en.wikipedia.org/wiki/Muon%20spin%20spectroscopy
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Muon spin spectroscopy, also known as µSR, is an experimental technique based on the implantation of spin-polarized muons in matter and on the detection of the influence of the atomic, molecular or crystalline surroundings on their spin motion. The motion of the muon spin is due to the magnetic field experienced by the particle and may provide information on its local environment in a very similar way to other magnetic resonance techniques, such as electron spin resonance (ESR or EPR) and, more closely, nuclear magnetic resonance (NMR).
Introduction
Muon spin spectroscopy is an atomic, molecular and condensed matter experimental technique that exploits nuclear detection methods. In analogy with the acronyms for the previously established spectroscopies NMR and ESR, muon spin spectroscopy is also known as µSR. The acronym stands for muon spin rotation, relaxation, or resonance, depending respectively on whether the muon spin motion is predominantly a rotation (more precisely a precession around a still magnetic field), a relaxation towards an equilibrium direction, or a more complex dynamic dictated by the addition of short radio frequency pulses. µSR does not require any radio-frequency technique to align the probing spin.
More generally speaking, muon spin spectroscopy includes any study of the interactions of the muon's magnetic moment with its surroundings when implanted into any kind of matter. Its two most notable features are its ability to study local environments, due to the short effective range of muon interactions with matter, and the characteristic time-window (10−13 – 10−5 s) of the dynamical processes in atomic, molecular and condensed media. The closest parallel to µSR is "pulsed NMR", in which one observes time-dependent transverse nuclear polarization or the so-called "free induction decay" of the nuclear polarization. However, a key difference is that in µSR one uses a specifically implanted spin (the muon's) and does not rely on internal nuclea
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https://en.wikipedia.org/wiki/Fine%20motor%20skill
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Fine motor skill (or dexterity) is the coordination of small muscles in movement with the eyes, hands and fingers. The complex levels of manual dexterity that humans exhibit can be related to the nervous system. Fine motor skills aid in the growth of intelligence and develop continuously throughout the stages of human development.
Types of motor skills
Motor skills are movements and actions of the bone structures. Typically, they are categorised into two groups: gross motor skills and fine motor skills. Gross motor skills are involved in movement and coordination of the arms, legs, and other large body parts. They involve actions such as running, crawling and swimming. Fine motor skills are involved in smaller movements that occur in the wrists, hands, fingers, feet and toes. Specifically, single joint movements are fine motor movements and require fine motor skills. They involve smaller actions such as picking up objects between the thumb and finger, writing carefully, and blinking.
Developmental stages
Through each developmental stage, motor skills gradually develop. They are first seen during infancy, toddler-hood, preschool and school age. "Basic" fine motor skills gradually develop and are typically mastered between the ages of 6–12 in children. Fine motor skills develop with age and practice. If deemed necessary, occupational therapy can help improve overall fine motor skills.
Infancy
Early fine motor skills are involuntary reflexes. The most notable involuntary reflex is the Darwinian reflex, a primitive reflex displayed in various newborn primates species. These involuntary muscle movements are temporary and often disappear after the first two months. After eight weeks, an infant will begin to voluntarily use fingers to touch. However, infants have not learned to grab at this stage.
Hand–eye coordination begins to develop at two to five months. Infants begin to reach for and grasp objects at this age. In 1952, Piaget found that even before infants are
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https://en.wikipedia.org/wiki/Geophysical%20%26%20Astrophysical%20Fluid%20Dynamics
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Geophysical & Astrophysical Fluid Dynamics is a bimonthly peer-reviewed scientific journal covering applications of fluid dynamics in the fields of astrophysics and geophysics. It was established in 1970 as Geophysical Fluid Dynamics, obtaining its current name in 1977. It is published by Taylor & Francis and the editor-in-chief is Andrew Soward (Newcastle University). According to the Journal Citation Reports, the journal has a 2020 impact factor of 1.451.
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https://en.wikipedia.org/wiki/Uterine%20cavity
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The uterine cavity is the inside of the uterus. It is triangular in shape, the base (broadest part) being formed by the internal surface of the body of the uterus between the openings of the fallopian tubes, the apex by the internal orifice of the uterus through which the cavity of the body communicates with the canal of the cervix. The uterine cavity where it enters the openings of the fallopian tubes is a mere slit, flattened antero-posteriorly.
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https://en.wikipedia.org/wiki/Schreckstoff
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In 1938, the Austrian ethologist Karl von Frisch made his first report on the existence of the chemical alarm signal known as Schreckstoff (fright substance) in minnows. An alarm signal is a response produced by an individual, the "sender", reacting to a hazard that warns other animals, the receivers, of danger. This chemical alarm signal is released only when the sender incurs mechanical damage, such as when it has been caught by a predator, and is detected by the olfactory system. When this signal reaches the receivers, they perceive a greater predation risk and exhibit an antipredator response. Since populations of fish exhibiting this trait survive more successfully, the trait is maintained via natural selection. While the evolution of this signal was once a topic of great debate, recent evidence suggests schreckstoff evolved as a defense against environmental stressors such as pathogens, parasites, and UVB radiation and that it was later co-opted by predators and prey as a chemical signal.
Background
Chemical alarm systems have been identified in a number of different taxa, including gastropods, echinoderms, amphibians and fishes. One of the most well-studied chemical alarm signals is schreckstoff, the use of which is widespread in the superorder Ostariophysi (e.g., minnows, characins, catfishes, etc.). About 64% of all freshwater fish species and 27% of all fish species worldwide are found in the ostariophysan superorder, which highlights the widespread use and importance of this chemical alarm system in fishes.
Schreckstoff in ostariophysans
The production of schreckstoff has been shown to be metabolically expensive and is therefore part of a conditional strategy that can only be employed by individuals with access to sufficient resources. One putative active ingredient in schreckstoff is hypoxanthine-3N-oxide (H3NO), which may be produced in club cells which will henceforth be referred to as "alarm substance cells". The nitrogen oxide functional g
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https://en.wikipedia.org/wiki/European%20Neural%20Network%20Society
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The European Neural Network Society (ENNS) is an association of scientists, engineers, students, and others seeking to learn about and advance understanding of artificial neural networks. Specific areas of interest in this scientific field include modelling of behavioral and brain processes, development of neural algorithms and applying neural modelling concepts to problems relevant in many different domains. Erkki Oja and John G. Taylor are past ENNS presidents and honorary executive board members. its president is Věra Kůrková.
Every year since 1991 ENNS organizes the International Conference on Artificial Neural Networks (ICANN). The history and the links to past conferences are available at the ENNS web site. This is one of the oldest and best established conferences on the subject, with proceedings published in Springer Lecture Notes in Computer Science, see index in DBLP bibliography database.
As a non-profit organization ENNS promotes scientific activities at European and at the national levels in cooperation with national organizations that focus on neural networks. Every year many stipends to attend ICANN conference are given. ENNS also sponsors other students and have given awards and prizes at co-sponsored events (schools, workshops, conferences and competitions).
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https://en.wikipedia.org/wiki/Phosphoribosylanthranilate%20isomerase
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In enzymology, a phosphoribosylanthranilate isomerase (PRAI) () is an enzyme that catalyzes the third step of the synthesis of the amino acid tryptophan.
This enzyme participates in the phenylalanine, tyrosine and tryptophan biosynthesis pathway, also known as the aromatic amino acid biosynthesis pathway
In yeast, it is encoded by the TRP1 gene.
Nomenclature
This enzyme belongs to the family of isomerases, specifically those intramolecular oxidoreductases interconverting aldoses and ketoses. The systematic name of this enzyme class is N-(5-phospho-beta-D-ribosyl)anthranilate aldose-ketose-isomerase. Other names in common use include:
PRA isomerase,
PRAI,
IGPS:PRAI (indole-3-glycerol-phosphate,
synthetase/N-5'-phosphoribosylanthranilate isomerase complex), and
N-(5-phospho-beta-D-ribosyl)anthranilate ketol-isomerase.
xPRAI (monomeric variant in Saccharmyces cerevisiae)
PRAI[ML256-452] (engineered variant of 1-(2-carboxy-phenylamino)-1-deoxy-D-ribulose 5-phosphate carboxylase: PRAI)
Reaction
Phosphoribosylanthranilate isomerase is one of the many enzymes within the biosynthesis pathway of tryptophan (an essential amino acid). The upstream* pathway substrates and intermediates are shown below (Fig. 2).
As seen in Fig. 3, N-(5'-phosphoribosyl)-anthranilate via this enzyme is converted into 1-(o-carboxyphenylamino)-1-deoxribulose 5-phosphate. As the name phosphoribosylanthranilate isomerase suggests, it functions as an isomerase, rearranging the parts of the molecule without adding or removing molecules or atoms.
The reaction seen in Fig. 3, is an intramolecular redox (reduction-oxidation) reaction. Its first step involves a proton transfer. This product intermediate, an enolamine, is fluorescent, which is useful for kinetic studies
within this pathway. However, this product is unstable, and quickly isomerases into an α-amino keto.
Note: Upstream/Downstream are relative to the compounds/molecules directly involved in phosphoribosylanthranilate isomerase
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https://en.wikipedia.org/wiki/Avellis%20syndrome
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Avellis syndrome is a neurological disorder characterized by a peculiar form of alternating paralysis. There is paralysis of the soft palate and vocal cords on one side and loss of pain sensation and temperature sense on the other side, including the extremities, trunk, and neck. It usually results from occlusion of the vertebral artery in lesions of the nucleus ambiguous and pyramidal tract. Horner's syndrome may be associated. In the original description, the vagus and glossopharyngeal nerves were involved; concomitant involvement of the neighbouring cranial nerves was observed later.
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https://en.wikipedia.org/wiki/Electroneutral%20cation-Cl
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In molecular biology, the electroneutral cation-Cl (electroneutral potassium chloride cotransporter) family of proteins are a family of solute carrier proteins. This family includes the products of the Human genes: SLC12A1, SLC12A1, SLC12A2, SLC12A3, SLC12A4, SLC12A5, SLC12A6, SLC12A7, SLC12A8 and SLC12A9.
The K-Cl co-transporter (KCC) mediates the coupled movement of K+ and Cl− ions across the plasma membrane of many animal cells. This transport is involved in the regulatory volume decrease in response to cell swelling in red blood cells, and has been proposed to play a role in the vectorial movement of Cl− across kidney epithelia. The transport process involves one for one electroneutral movement of K+ together with Cl−, and, in all known mammalian cells, the net movement is outward.
The neuronal KCC subtype KCC2 is cell-volume insensitive and plays a unique role in maintaining low intracellular Cl−concentration, which is required in neurones for the functioning of Cl− dependent fast synaptic inhibition, mediated by certain neurotransmitters, such as gamma-aminobutyric acid (GABA) and glycine.
Three isoforms of the K-Cl co-transporter have been described, termed KCC1 (SLC12A4), KCC2 (SLC12A5), and KCC3 (SLC12A6), containing 1085, 1116 and 1150 amino acids, respectively. They are predicted to have 12 transmembrane (TM) regions in a central hydrophobic domain, together with hydrophilic N- and C-termini that are likely cytoplasmic. Comparison of their sequences with those of other ion-transporting membrane proteins reveals that they are part of a new superfamily of cation-chloride co-transporters, which includes the Na-Cl and Na-K-2Cl co-transporters. KCC1 and KCC3 are widely expressed in human tissues, while KCC2 is expressed only in brain neurons, making it likely that this is the isoform responsible for maintaining low Cl− concentration in neurons. A study in the model organism C. elegans found that the KCC3 ortholog functions in glial cells to regulate animal
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https://en.wikipedia.org/wiki/32%20%28number%29
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32 (thirty-two) is the natural number following 31 and preceding 33.
In mathematics
32 is the fifth power of two (), making it the first non-unitary fifth-power of the form p5 where p is prime. 32 is the totient summatory function over the first 10 integers, and the smallest number with exactly 7 solutions for . The aliquot sum of a power of two () is always one less than the number itself, therefore the aliquot sum of 32 is 31.
The product between neighbor numbers of 23, the dual permutation of the digits of 32 in decimal, is equal to the sum of the first 32 integers: .
32 is the ninth -happy number, while 23 is the sixth. Their sum is 55, which is the tenth triangular number, while their difference is .
32 is also a Leyland number expressible in the form , where:
On the other hand, a regular 32-sided icosidodecagon contains distinct symmetries.
There are collectively 32 uniform colorings to the 11 regular and semiregular tilings.
The product of the five known Fermat primes is equal to the number of sides of the largest regular constructible polygon with a straightedge and compass that has an odd number of sides, with a total of sides numbering
The first 32 rows of Pascal's triangle in binary represent the thirty-two divisors that belong to this number, which is also the number of sides of all odd-sided constructible polygons with simple tools alone (if the monogon is also included).
There are 32 three-dimensional crystallographic point groups and 32 five-dimensional crystal families, and the maximum determinant in a 7 by 7 matrix of only zeroes and ones is 32. In sixteen dimensions, the sedenions generate a non-commutative loop of order 32, and in thirty-two dimensions, there are at least 1,160,000,000 even unimodular lattices (of determinants 1 or −1); which is a marked increase from the twenty-four such Niemeier lattices that exists in twenty-four dimensions, or the single lattice in eight dimensions (these lattices only exist for dimensions )
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https://en.wikipedia.org/wiki/Transverse%20orientation
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Transverse orientation, keeping a fixed angle on a distant source of light for orientation, is a proprioceptive response displayed by some insects such as moths.
By maintaining a constant angular relationship to a bright celestial light, such as the moon, they can fly in a straight line. Celestial objects are so far away that, even after travelling great distances, the change in angle between the moth and the light source is negligible; further, the moon will always be in the upper part of the visual field, or on the horizon. When a moth encounters a much closer artificial light and uses it for navigation, the angle changes noticeably after only a short distance, in addition to being often below the horizon. The moth instinctively attempts to correct by turning toward the light, thereby causing airborne moths to come plummeting downward, and resulting in a spiral flight path that gets closer and closer to the light source.
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https://en.wikipedia.org/wiki/Cutaneous%20small-vessel%20vasculitis
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Cutaneous small-vessel vasculitis (CSVV), is inflammation of small blood vessels, usually accompanied by small lumps beneath the skin. The condition is also known as hypersensitivity vasculitis, cutaneous leukocytoclastic vasculitis, hypersensitivity angiitis, cutaneous leukocytoclastic angiitis, cutaneous necrotizing vasculitis and cutaneous necrotizing venulitis,
It is the most common form of vasculitis seen in clinical practice, usually caused by inflammation of post-capillary venules in the dermis).
"Leukocytoclastic" refers to the damage caused by nuclear debris from infiltrating neutrophils in and around the vessels.
Signs and symptoms
Skin lesions
Initially red to pink, flat spots (formally, "macules") and raised bumps (formally, "papules") may be seen on the skin.
Once fully developed, the classic appearance is "non-blanching, palpable purpura". This appears as deep red to purple spots that feel raised to the touch. Purpura refers to the red-purple discolored spots, while palpable implies that these spots can be felt as raised from the surrounding skin. Additionally, when gently pressed, the color does not fade to a lighter color ("non-blanching"). The red-purple color of the lesions is due to the inflammation in the blood vessels causing red blood cells to escape into the dermis skin layer.
Small fluid-filled blisters (or "vesicles"), pus-filled bumps resembling a pimple (or "pustules"), or shallow ulcers may also develop but are less common.
The location of skin lesions varies but are most commonly found symmetrically below the waist, primarily on the buttocks and legs. Other distributions include localized areas on the upper body or over several areas of the body.
With treatment, the lesions typically resolve in weeks to months and leave behind flat spots that are darker than the surrounding skin (see "Postinflammatory hyperpigmentation" on "Hyperpigmentation").
A portion of cases may be persistent or recurrent. This tends to occur when the va
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https://en.wikipedia.org/wiki/AP%20Physics%20B
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Advanced Placement (AP) Physics B was a physics course administered by the College Board as part of its Advanced Placement program. It was equivalent to a year-long introductory university course covering Newtonian mechanics, electromagnetism, fluid mechanics, thermal physics, waves, optics, and modern physics. The course was algebra-based and heavily computational; in 2015, it was replaced by the more concept-focused AP Physics 1 and AP Physics 2.
Exam
The exam consisted of a 70 MCQ section, followed by a 6-7 FRQ section. Each section was 90 minutes and was worth 50% of the final score. The MCQ section banned calculators, while the FRQ allowed calculators and a list of common formulas. Overall, the exam was configured to approximately cover a set percentage of each of the five target categories:
Purpose
According to the College Board web site, the Physics B course provided "a foundation in physics for students in the life sciences, a pre medical career path, and some applied sciences, as well as other fields not directly related to science."
Discontinuation
Starting in the 2014–2015 school year, AP Physics B was no longer offered, and AP Physics 1 and AP Physics 2 took its place. Like AP Physics B, both are algebra-based, and both are designed to be taught as year-long courses.
Grade distribution
The grade distributions for the Physics B scores from 2010 until its discontinuation in 2014 are as follows:
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https://en.wikipedia.org/wiki/Piezoelectrochemical%20transducer%20effect
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The piezoelectrochemical transducer effect (PECT) is a coupling between the electrochemical potential and the mechanical strain in ion-insertion-based electrode materials. It is similar to the piezoelectric effect – with both exhibiting a voltage-strain coupling - although the PECT effect relies on movement of ions within a material microstructure, rather than charge accumulation from the polarization of electric dipole moments.
Many different materials have been shown to exhibit a PECT effect including: lithiated graphite.; carbon fibers inserted with lithium, sodium, and potassium; sodiated black phosphorus; lithiated aluminium; lithium cobalt oxide; vanadium oxide nanofibers inserted with lithium and sodium; and lithiated silicon.
These materials all exhibit a voltage-strain coupling, whereby the material expands when it is charged with ions, and contracts when it is discharged. The reverse is also true: when applying a mechanical strain the electrical potential changes.
This has led to various proposals of applications for the PECT effect with research focusing on actuators, strain-sensors, and energy harvesters.
Origins
The PECT effect was first reported by Dr. F Lincoln Vogel in 1981 when studying how intercalation voltages could be used to provide an actuation force in graphitized carbon fibres. The research used sulphate (SO4) ions from sulfuric acid to intercalate into the microstructure of carbon fibers, forming graphite intercalation compounds (GICs). It was hypothesized that an axial strain of up to 2% should be possible, however only 0.2% was observed due to experimental limitations.
The effect is often explained by the theories of Larché and Cahn who derived mathematical formulations for the equilibrium relationships between the electric potential, chemical potential, and mechanical stress in solid materials. In summary the theory states that solid materials under mechanical stress undergo a change in chemical potential, which in turn affects t
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https://en.wikipedia.org/wiki/Dynamic%20Analysis%20and%20Replanning%20Tool
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The Dynamic Analysis and Replanning Tool, commonly abbreviated to DART, is an artificial intelligence program used by the U.S. military to optimize and schedule the transportation of supplies or personnel and solve other logistical problems.
DART uses intelligent agents to aid decision support systems located at the U.S. Transportation and European Commands. It integrates a set of intelligent data processing agents and database management systems to give planners the ability to rapidly evaluate plans for logistical feasibility. By automating evaluation of these processes DART decreases the cost and time required to implement decisions.
DART achieved logistical solutions that surprised many military planners. Introduced in 1991, DART had by 1995 offset the monetary equivalent of all funds DARPA had channeled into AI research for the previous 30 years combined.
Development and introduction
DARPA funded the MITRE Corporation and Carnegie Mellon University to analyze the feasibility of several intelligent planning systems. In November 1989, a demonstration named The Proud Eagle Exercise indicated many inadequacies and bottlenecks within military support systems. In July, DART was previewed to the military by BBN Systems and Technologies and the ISX Corporation (now part of Lockheed Martin Advanced Technology Laboratories) in conjunction with the United States Air Force Rome Laboratory. It was proposed in November 1990, with the military immediately demanding that a prototype be developed for testing. A rapid development cycle allowed for a prototype to be developed in eight weeks, which was introduced in 1991 to the USTRANSCOM at the beginning of Operation Desert Storm during the Gulf War.
Impact
Directly following its launch, DART solved several logistical nightmares, saving the military millions of dollars. Military planners were aware of the tremendous obstacles facing moving military assets from bases in Europe to prepared bases in Saudi Arabia, in preparation
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https://en.wikipedia.org/wiki/Double%20Planetoid
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Double Planetoid is a wood engraving print by the Dutch artist M. C. Escher, first printed in 1949.
Description
Double Planetoid is printed in four colors from four wood blocks. It depicts a planetoid in the shape of a compound of two tetrahedra, interpenetrating each other to form a stellated octahedron. One of the two tetrahedra is entirely covered by architecture, while the other is a wilderness populated by saurian creatures. The planetoid is shown within a circular black field, in diameter.
Themes
Double Planetoid is part of a series of Escher's prints from the 1940s and 1950s that depict small polyhedral planets, also including Gravitation (1952) and Tetrahedral Planetoid (1954), and possibly in the same universe as his print Stars (1948). It has thematic connections with other Escher prints from the same period that provide simultaneous views of intermingled worlds, including the more realistic prints Puddle (1952) and Three Worlds (1955), and is one of many Escher works using the geometry of polyhedra and polyhedral compounds.
Collections
Copies of the print are included in the permanent collections of the National Gallery of Canada, the US National Gallery of Art, and the Museum of Fine Arts, Boston.
See also
Tetrahedral hypothesis, the discredited scientific theory that the arrangement of the Earth's continents comes from the geometry of a tetrahedron
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