source stringlengths 31 227 | text stringlengths 9 2k |
|---|---|
https://en.wikipedia.org/wiki/Information%20filtering%20system | An information filtering system is a system that removes redundant or unwanted information from an information stream using (semi)automated or computerized methods prior to presentation to a human user. Its main goal is the management of the information overload and increment of the semantic signal-to-noise ratio. To do this the user's profile is compared to some reference characteristics. These characteristics may originate from the information item (the content-based approach) or the user's social environment (the collaborative filtering approach).
Whereas in information transmission signal processing filters are used against syntax-disrupting noise on the bit-level, the methods employed in information filtering act on the semantic level.
The range of machine methods employed builds on the same principles as those for information extraction. A notable application can be found in the field of email spam filters. Thus, it is not only the information explosion that necessitates some form of filters, but also inadvertently or maliciously introduced pseudo-information.
On the presentation level, information filtering takes the form of user-preferences-based newsfeeds, etc.
Recommender systems and content discovery platforms are active information filtering systems that attempt to present to the user information items (film, television, music, books, news, web pages) the user is interested in. These systems add information items to the information flowing towards the user, as opposed to removing information items from the information flow towards the user. Recommender systems typically use collaborative filtering approaches or a combination of the collaborative filtering and content-based filtering approaches, although content-based recommender systems do exist.
History
Before the advent of the Internet, there are already several methods of filtering information; for instance, governments may control and restrict the flow of information in a given country by means |
https://en.wikipedia.org/wiki/Marguerite%20Davis | Marguerite Davis (September 16, 1887 – September 19, 1967) was an American biochemist, co-discoverer of vitamins A and B with Elmer Verner McCollum in 1913. Their research greatly influenced later research on nutrition.
Early life
Davis was born on September 16, 1887, in Racine, Wisconsin, to John Jefferson Davis, a local physician and botanist, who taught at the University of Wisconsin. In his 1964 autobiography, Elmer Verner McCollum says that Davis was physically handicapped by severe burns that she received at age ten while playing at a bonfire when her clothing caught fire.
Education
Davis' background and scientific interests led her to enroll at the University of Wisconsin in 1906. In 1908, she transferred to the University of California at Berkeley and received her bachelor of science degree in home economics in 1910. After graduation, Davis returned to the University of Wisconsin where she completed some graduate work, but did not complete a master's degree. At the University of Wisconsin, Davis began her work as a research assistant with McCollum.
Discovery of vitamins A and B
Davis worked as an assistant for McCollum, caring for a large rat colony and helping expand it. Davis helped McCollum carry out "ten or more times as many experiments as [he] alone could manage". They were attempting to create mixtures that could replace food in animal diets, specifically studying trace chemicals in foods that are essential to life. These substances were called "vitamines", as they hypothesized that they were the organic molecule "amines".
In 1913, Davis and McCollum identified what they called "fat-soluble A", a substance found in fats that is essential to life. They distinguished it from another substance described by Dutch chemist Christiaan Eijkman, which they studied and called "water-soluble B." These were later renamed Vitamins A and B, after long research on rats. The discovery of two vitamins paved the way to further research in nutrition.
Their disco |
https://en.wikipedia.org/wiki/Korea%20Citation%20Index | The Korea Citation Index is a citation index covering research in South Korea.
See also
Korea Research Foundation
Science Citation Index
Social Sciences Citation Index
Arts and Humanities Citation Index
External links
Bibliographic databases and indexes
Libraries in South Korea
Citation indices |
https://en.wikipedia.org/wiki/Point-finite%20collection | In mathematics, a collection or family of subsets of a topological space is said to be point-finite if every point of lies in only finitely many members of
A metacompact space is a topological space in which every open cover admits a point-finite open refinement. Every locally finite collection of subsets of a topological space is also point-finite.
A topological space in which every open cover admits a locally finite open refinement is called a paracompact space. Every paracompact space is therefore metacompact. |
https://en.wikipedia.org/wiki/Patching%20and%20Capping | The aggregation of fluorescently tagged antibodies that are associated with proteins on membranes of living cells. The aggregation appears as a cap or a patch in the fluorescence microscope and is due to the bivalent nature of antibodies. Patching and capping were critical in demonstrating the fluid nature of plasma membranes.
Variations in density within the specimen are amplified to enhance contrast in unstained cells which is especially useful for examining living unpigmented cells. In other words, phase contrast is a contrast-enhancing optical technique that can be used to produce high contrast images such as living cells and subcellular including nuclei and other organelles. One of the major advantages of using phase contrast microscopy is that living cells can be examined in their natural state without being killed, fixed, or especially stained. As a result, biological processes in the cell can be observed and recorded in high contrast with sharp clarity of minute specimen details.
When the ligand binds to its specific receptor, the ligand-receptor complex accumulates in the coated pits. In many cells these pits and complexes begin to concentrate in one area of a cell. Cytochemically, this appears as patches of label on the cell surface (patching). Eventually, the patches coalesce to form a cap at one pole of the cell (capping). Not all cells form caps, but most do form patches. The pre-concentration process minimizes the amount of fluid that is taken up in the vesicle.
See also
Immunofluorescence |
https://en.wikipedia.org/wiki/RapidMind | RapidMind Inc. was a privately held company founded and headquartered in Waterloo, Ontario, Canada, acquired by Intel in 2009. It provided a software product that aims to make it simpler for software developers to target multi-core processors and accelerators such as graphics processing units (GPUs).
History
RapidMind was started in 2004 based on the academic research related to the Sh project at the University of Waterloo. It received a seed round of financing (amount undisclosed) at the beginning of 2006, and raised its Series A round of $10 million Canadian in April 2007.
RapidMind was acquired by Intel on 19 August 2009. Intel continued to sell RapidMind's primary product, a Multi-core Development Platform, through 2010. The RapidMind team and technology was integrated into the Intel Ct research project. The results of the combination were introduced in September 2010 as Intel Array Building Blocks.
Multi-core development platform
The platform was exposed as a set of C++ libraries, which provide types and operations used to express parallel computations. The programming model was primarily data parallel, although it was sufficiently generic to express task-parallel operations. The platform targeted multi-core x86 processors, GPUs (via OpenCL), and the Cell processor. |
https://en.wikipedia.org/wiki/Vitamin%20A%20receptor | Vitamin A receptor, Stimulated by retinoic acid 6 or STRA6 protein was originally discovered as a transmembrane cell-surface receptor for retinol-binding protein. STRA6 is unique as it functions both as a membrane transporter and a cell surface receptor, particularly as a cytokine receptor. In fact, STRA6 may be the first of a whole new class of proteins that might be known as "cytokine signaling transporters." STRA6 is primarily known as the receptor for retinol binding protein and for its relevance in the transport of retinol to specific sites such as the eye (Vitamin A). It does this through the removal of retinol (ROH) from the holo-Retinol Binding Protein (RBP) and transports it into the cell to be metabolized into retinoids and/or kept as a retinylester. As a receptor, after holo-RBP is bound, STRA6 activates the JAK/STAT pathway, resulting in the activation of transcription factor, STAT5. These two functions—retinol transporter and cytokine receptor—while using different pathways, are processes that depend on each other.
Mechanism of action
Overview
In the first step, holo-retinol binding protein (holo-RBP; simply means RBP bound to retinol, i.e. the RBP-ROH complex) binds to the extracellular portion of STRA6. This facilitates the release of retinol through the transporter. ROH is then transferred to cellular retinol binding protein 1 (CRBP1), an intracellular acceptor of retinol that attaches to the CRBP Binding Loop (or CBL) on STRA6. This transport of ROH, in turn, activates JAK2, thereby phosphorylating STRA6 at the Y643 (tyrosine) residue. This phosphorylation enables the extension of the CBL further into the cell. Holo-CRBP-I, leaves the CBL and is replaced by apo-CRBP-I (unbound). Holo-CRBP-I will continue to the Endoplasmic Reticulum (ER) where lecithin retinol acyltransferase (LRAT) is bound. ROH is released to LRAT which will convert retinol into retinylesters. Following the release of holo-CRBP-I from intercellular STRA6, STAT5 is recru |
https://en.wikipedia.org/wiki/Kinnernet | Kinnernet is a series of invitation-only unconference events formed by entrepreneurs, technologists, startup founders, scientists, media professionals, and creatives.
Format
Described as "a wild out of the box, irreverent, bottom-up innovation, creativity and cultural unconference", the event gathers each year 100-200 innovators working in the media, art, technology or creative industries, with the mission to: "meet, share our visions and invent desirable futures together".
The festival mixes in depth conversations, debates, workshops, but also creative and artistic moments. All participants are equal and contributors and set up the programme by posting the topics on their minds on large wiki-boards. The Festival aims to create and develop each year innovative and contributive projects.
Forbes described it as follows: "Take the ‘no speakers or topics’ mantra to the extreme and you have the unconference [...] Gather an invitation-only list of fantastic people, give them an empty dry erase board with meeting times and locations and let the magic happen."
History
The first Kinnernet event was held in the spring of 2003, organised by Yossi Vardi, founding investor of ICQ
The conference is invitation-only and self-organized, originally inspired by Tim O'Reilly's Foo Camp.
Some discussion points become topics at TheMarker, a two-day Internet business conference in Tel Aviv.
Since its inception, Kinnernets have opened throughout the world, including Avallon (France), Venice (Italy), Alcobaça (Portugal), Vihula Manhor (Estonia), and Ciudad del Saber (Panama).
Locations
Nes Hrim, Israel, since 2003 (link)
Avallon, France, since 2013 (link)
Vernice, Italy, since 2017 (link)
Alcobaça, Portugal, since 2018 (link)
Vihula Manor, Estonia, since 2019 (link)
Ciudad del Saber, Panama, since 2019 (link)
Dubai, UAE, since 2022 (link) |
https://en.wikipedia.org/wiki/Thermosome | A thermosome is a group II chaperonin protein complex that functions in archaea. It is the homolog of eukaryotic CCT. This group II chaperonin is an ATP-dependent chaperonin that is responsible for folding or refolding of incipient or denatured proteins. A thermosome has two rings, each consisting of eight subunits, stacked together to form a cylindrical shape with a large cavity at the center. The thermosome is also defined by its heterooligomeric nature. The complex consists of that alternate location within its two rings.
Being a Group II chaperonin, the thermosome has a similar structure to group I chaperonins. The main difference, however, lies in the existence of a helical protrusion in the thermosome which composes of a built-in lid of the hydrophilic cavity. Not only is thermosome ATP-dependent, but the mechanism in which thermosome shifts from open to close conformation is also temperature-dependent. The open conformation of the ATP-thermosome exists mainly at low temperatures. Whereas, the closed conformation of the thermosome occurs when heating to physiological temperature.
Similar to the GroEL chaperonins in bacteria, the thermosome shows negative cooperativity since the two rings of the thermosome show different affinities for the binding of ATP. However, unlike the GroEL system, the thermosome is less affected by the concentration of ATP. In the absence of ATP, the thermosome does not have a preference for the T-state over the R-state. There is, however, an inhibition for the loading of the second ring when ADP is bound to the first ring.
The N-terminus and C-terminus of thermosomes are arranged in an anti-parallel fashion and their interactions form part of the intra-ring interactions. Both the N-terminus and C-terminus of the thermosome have charged residues which interact with each other to contribute to the thermal stability of the thermosome. The cpn-α and cpn-β thermosomes specifically show maximum thermal stability in the pH range of 7.0 t |
https://en.wikipedia.org/wiki/Fleming%20valve | The Fleming valve, also called the Fleming oscillation valve, was a thermionic valve or vacuum tube invented in 1904 by English physicist John Ambrose Fleming as a detector for early radio receivers used in electromagnetic wireless telegraphy. It was the first practical vacuum tube and the first thermionic diode, a vacuum tube whose purpose is to conduct current in one direction and block current flowing in the opposite direction. The thermionic diode was later widely used as a rectifier — a device that converts alternating current (AC) into direct current (DC) — in the power supplies of a wide range of electronic devices, until beginning to be replaced by the selenium rectifier in the early 1930s and almost completely replaced by the semiconductor diode in the 1960s. The Fleming valve was the forerunner of all vacuum tubes, which dominated electronics for 50 years. The IEEE has described it as "one of the most important developments in the history of electronics", and it is on the List of IEEE Milestones for electrical engineering.
How it works
The valve consists of an evacuated glass bulb containing two electrodes: a cathode in the form of a "filament", a loop of carbon or fine tungsten wire, similar to that used in the light bulbs of the time, and an anode (plate) consisting of a sheet metal plate. Although in early versions, the anode was a flat metal plate placed next to the cathode, in later versions, it became a metal cylinder surrounding the cathode. In some versions, a grounded copper screen surrounded the bulb to shield it against the influence of external electric fields.
In operation, a separate current flows through the cathode "filament", heating it so that some of the electrons in the metal gain sufficient energy to escape their parent atoms into the vacuum of the tube, a process called thermionic emission. The AC to be rectified is applied between the filament and the plate. When the plate has a positive voltage with respect to the filame |
https://en.wikipedia.org/wiki/Adenosine%20thiamine%20triphosphate | Adenosine thiamine triphosphate (AThTP), or thiaminylated adenosine triphosphate, is a natural thiamine adenine nucleotide. It was discovered in Escherichia coli where it may account for up to 15 - 20% of total thiamine under carbon starvation. AThTP also exists in eukaryotic organisms such as yeast, roots of higher plants and animal tissues, albeit at a much lower concentration. It was found to exist in small amounts in the muscle, heart, brain, kidneys and liver of mice.
In E. coli AThTP is synthesized from thiamine diphosphate (ThDP) according to the following reaction catalyzed by thiamine diphosphate adenylyl transferase:
ThDP + ATP (ADP) ↔ AThTP + PPi (Pi)
Structure and function
The molecule is made up of thiamine and adenosine joined together with phosphate groups. It is similar in structure to NAD+. The function of AThTP is not currently known but it has been shown to inhibit the activity of PARP-1. |
https://en.wikipedia.org/wiki/N-terminal%20telopeptide | The N-terminal telopeptide (NTX), also known as amino-terminal collagen crosslinks, is the N-terminal telopeptide of fibrillar collagens such as collagen type I and type II. It is used as a biomarker to measure the rate of bone turnover. NTX can be measured in the urine (uNTX) or serum (serum NTX). The peptide consists of eight amino acids with the sequence YDEKSTGG.
Usefulness of NTX as a biomarker
Evaluating an individual's rate of bone turnover, termed bone remodeling, directly may be important in assessing his or her potential nonsurgical treatment response as well as evaluating his or her risk of developing complications during healing following surgical intervention. To determine an individual's rate of bone turnover, numerous biomarkers are available in the body fluids that can be correlated to this rate, and one such biomarker is NTX.
However, while NTX does fluctuate in a very sensitive manner in line with bone resorption patterns, they are not very specific, in that they may vary spontaneously without physiologic intervention. For example, NTX levels may drop by 50% from day to day with no treatment, thus, making NTX levels unconvincing evidence of treatment effect.
Conversely, the serum CTX biomarker, described in 2000 by Rosen, appears to be a much more effective and valuable indicator of bone resorption rate.
See also
C-terminal telopeptide |
https://en.wikipedia.org/wiki/Mii | A Mii ( ) is a customizable avatar used on several Nintendo video game consoles and mobile apps. The name Mii is a portmanteau of “Wii” and “me”, referring to them typically being avatars of the players. Miis were first introduced on the Wii console in 2006 and later appeared on the DS, 3DS, the Wii U, the Switch, and various apps for smart devices such as Miitomo. Miis can be created using different body, facial and clothing features, and can then be used as characters within games on the consoles, either as an avatar of a specific player (such as in the Wii series) or in some games (such as Tomodachi Life and Miitopia) portrayed as characters with their own personalities. Miis can be shared and transferred between consoles, either manually or automatically with other users over the internet and local wireless communications.
On the 3DS and Wii U, user accounts are associated with a Mii as their avatar and used as the basis of the systems' social networking features, most prominently the now-defunct Miiverse. On the Nintendo Switch, a Mii can still be used as an account avatar, but avatars depicting various Nintendo characters are also available. Miis are also used as profile pictures for Nintendo Accounts and can be used in Nintendo smart device games such as Super Mario Run, Mario Kart Tour and the now-defunct Miitomo.
Games such as Wii Sports, Wii Sports Resort, Mario Kart Wii, Mario Kart 8, Go Vacation, Super Mario Maker 2, Super Smash Bros. Ultimate and New Super Mario Bros. U Deluxe use Miis as playable characters.
History
Nintendo's first public debut of free-form personal avatar software was at the Game Developers Conference in 1997, during the Nintendo 64 era. There, Shigeru Miyamoto said that the personal avatar concept had originally been intended as a Famicom demo, where a user could draw a face onto an avatar. Miyamoto commented that the concept could not be turned into a game and the concept was suspended.
In 1999, the 64DD (a disk drive peripher |
https://en.wikipedia.org/wiki/Echinophora%20sibthorpiana | Tarhana herb or Turkish pickling herb, Echinophora sibthorpiana or Echinophora tenuifolia L. subsp. sibthorpiana (Guss.) Tutin (Turkish çörtük), is a herb sometimes used as a flavoring in tarhana and in pickles. It may also improve the fermentation of tarhana. (Deghirmencioghlu 2005)
The primary essential oils it contains are δ-3-carene, methyleugenol, and α-phellandrene. (Özcan 2003)
Some authors indicate that Hippomarathrum cristatum is the "tarhana herb". |
https://en.wikipedia.org/wiki/Ram%20press%20%28food%29 | A ram press is a device or machine commonly used to press items with a mechanical ram, such as with a plunger, piston, force pump, or hydraulic ram. In food preparation, there are various kinds of ram presses:
The fruit ram press and cider ram press are both types of fruit presses that extract the juices out of the fruit through pressure. The second makes apple cider.
An oil seed ram press is also known as an oil ram press and it extracts the oil out of oil seeds. |
https://en.wikipedia.org/wiki/Astron%20%28wristwatch%29 | The Astron wristwatch, formally known as the Seiko Quartz-Astron 35SQ, was the world's first "quartz clock" wristwatch. It is now registered on the List of IEEE Milestones as a key advance in electrical engineering.
History
The Astron was unveiled in Tokyo on December 25, 1969, after ten years of research and development at Suwa Seikosha (currently named Seiko Epson), a manufacturing company of Seiko Group. Within one week 100 gold watches had been sold, at a retail price of 450,000 yen (US$1,250) each (at the time, equivalent to the price of a medium-sized car). Essential elements included a XY-type quartz oscillator of (8192 = 213), a hybrid integrated circuit, and a phase locked ultra-small stepping motor to turn its hands. According to Seiko, Astron was accurate to ±5 seconds per month or one minute per year, and its battery life was 1 year or longer.
Anniversaries
In March 2010, at the Baselworld watch fair and trade show in Switzerland, Seiko previewed a limited edition new version of the watch and related designs of the original Astron watch, commemorating the fortieth anniversary in December 2009 of the debut of the Astron watch.
Second Generation
Seiko used the "Astron" trademark again as "Seiko Astron" when it released a satellite radio-wave solar-powered wristwatch using GPS satellites in 2012.
50th Anniversary Model
In 2019, Seiko released several limited edition Astron models to commemorate the 50th anniversary of the quartz Astron. Among them, the model produced in a limited edition of 50 pieces (3.8 million yen) mimics the original case design and has a rough engraving pattern by craftsmen belonging to Epson's "Micro Artist Workshop".
Footnotes
(alternate version ) |
https://en.wikipedia.org/wiki/MAG%20InnoVision | MAG Innovision is a Taiwan-headquartered manufacturer and provider of visual technology, specifically CRT monitors, liquid crystal displays, projectors, plasma displays, and HDTV technology. The company was founded by William Wang when he was 26 years old.
In the early to mid-1990s, its products were one of the top-rated in the market for computer CRT monitors in the North American market, alongside Sony, NEC, and Panasonic. Since the late 1990s and 2000s, these companies have been displaced by ViewSonic, and more recently by Samsung and LG, as the latter were at the forefront of fledgling LCD technology. |
https://en.wikipedia.org/wiki/False%20vivipary | False vivipary is an abnormal condition found in many types of plants in which a plantlet is produced where the flower should appear. It is not a completely understood topic, but some say it could be caused by a hormonal mistake. The plantlet which appears can be rooted and grown like normal plants. This abnormal behavior can occasionally be seen in many types of carnivorous plants.
See also
Propagule
Vivipary |
https://en.wikipedia.org/wiki/PMX%20%28technology%29 | PMX refers to the technology developed by Pelmorex to generate local weather information on The Weather Network. PMX consists of computers, typically installed at a cable headend, that takes data fed to it (the video feed of The Weather Network, forecast information, and triggers to run said forecasts) and packages it for broadcast. Unlike the Weather Star systems, it does not generate full graphical or video segments, rather the information is super-imposed over the main video feed. There are 4 different PMX units: PMX-1500, PMX-3200, PMX-NG and PMX-XD.
History
PMX was developed by Pelmorex in 1995 as a standard localization system that would replace the units and the text based that were still used in smaller communities. The PMX technology quickly rolled out starting in 1996, with all communities receiving the new units by 1998. PMX generates local weather information to over 1200 communities across Canada.
Timeline
1996-1998: PMX-1500 units are gradually deployed at major cable head-ends locations across Canada. They were originally formatted as a replica of the previous WeatherSTAR units, only with a slightly different icon and font set. The earliest known date of a PMX unit working is March 28, 1996, from Timmins, ON.
December 1997: Format changes occur with PMX-1500 system. Notable changes include, extended forecasts for the next 5 days, and national forecast maps immediately following the Local Forecast. The maps were discontinued one year later.
April 1999: Topographical Satellite and Radar Maps are introduced, replacing the solid color maps previously used.
August 2001: The PMX-1500 receives minor graphical updates, including an updated font set and fade effects in various segments.
Winter 2001: New icons are introduced to the PMX-1500 system. The 7-day outlook and the short-term precipitation forecast is also introduced.
July 2002: The classic current weather conditions ticker is replaced with a bar containing both current conditions and forecasts at a |
https://en.wikipedia.org/wiki/Nicastrin | Nicastrin, also known as NCSTN, is a protein that in humans is encoded by the NCSTN gene.
Function
Nicastrin (abbreviated NCT) is a protein that is part of the gamma secretase protein complex, which is one of the proteases involved in processing amyloid precursor protein (APP) to the short Alzheimer's disease-associated peptide amyloid beta. The other proteins in the complex are PSEN1 (presenilin-1), which is the catalytically active component of the complex, APH-1 (anterior pharynx-defective 1), and PEN-2 (presenilin enhancer 2). Nicastrin itself is not catalytically active, but instead promotes the maturation and proper trafficking of the other proteins in the complex, all of which undergo significant post-translational modification before becoming active in the cell. Nicastrin has also been identified as a regulator of neprilysin, an enzyme involved in the degradation of amyloid beta fragment.
History
The protein was named after the Italian country Nicastro, reflecting the fact that Alzheimer's disease was described in 1963 after studying descendants of an extended family originating in the country of Nicastro that had familial Alzheimer's disease (FAD).
Interactions
Nicastrin has been shown to interact with PSEN1 and PSEN2. |
https://en.wikipedia.org/wiki/Image%20rectification | Image rectification is a transformation process used to project images onto a common image plane. This process has several degrees of freedom and there are many strategies for transforming images to the common plane. Image rectification is used in computer stereo vision to simplify the problem of finding matching points between images (i.e. the correspondence problem), and in geographic information systems to merge images taken from multiple perspectives into a common map coordinate system.
In computer vision
Computer stereo vision takes two or more images with known relative camera positions that show an object from different viewpoints. For each pixel it then determines the corresponding scene point's depth (i.e. distance from the camera) by first finding matching pixels (i.e. pixels showing the same scene point) in the other image(s) and then applying triangulation to the found matches to determine their depth.
Finding matches in stereo vision is restricted by epipolar geometry: Each pixel's match in another image can only be found on a line called the epipolar line.
If two images are coplanar, i.e. they were taken such that the right camera is only offset horizontally compared to the left camera (not being moved towards the object or rotated), then each pixel's epipolar line is horizontal and at the same vertical position as that pixel. However, in general settings (the camera does move towards the object or rotate) the epipolar lines are slanted. Image rectification warps both images such that they appear as if they have been taken with only a horizontal displacement and as a consequence all epipolar lines are horizontal, which slightly simplifies the stereo matching process. Note however, that rectification does not fundamentally change the stereo matching process: It searches on lines, slanted ones before and horizontal ones after rectification.
Image rectification is also an equivalent (and more often used) alternative to perfect camera coplanarity. Even |
https://en.wikipedia.org/wiki/Boolean%20operations%20on%20polygons | Boolean operations on polygons are a set of Boolean operations (AND, OR, NOT, XOR, ...) operating on one or more sets of polygons in computer graphics. These sets of operations are widely used in computer graphics, CAD, and in EDA (in integrated circuit physical design and verification software).
Algorithms
Greiner–Hormann clipping algorithm
Vatti clipping algorithm
Sutherland–Hodgman algorithm (special case algorithm)
Weiler–Atherton clipping algorithm (special case algorithm)
Uses in software
Early algorithms for Boolean operations on polygons were based on the use of bitmaps. Using bitmaps in modeling polygon shapes has many drawbacks. One of the drawbacks is that the memory usage can be very large, since the resolution of polygons is proportional to the number of bits used to represent polygons. The higher the resolution is desired, the more the number of bits is required.
Modern implementations for Boolean operations on polygons tend to use plane sweep algorithms (or Sweep line algorithms). A list of papers using plane sweep algorithms for Boolean operations on polygons can be found in References below.
Boolean operations on convex polygons and monotone polygons of the same direction may be performed in linear time.
See also
Boolean algebra
Computational geometry
Constructive solid geometry, a method of defining three-dimensional shapes using a similar set of operations
Geometry processing
General Polygon Clipper, a C library which computes the results of clipping operations
Notes
Bibliography
Mark de Berg, Marc van Kreveld, Mark Overmars, and Otfried Schwarzkopf, Computational Geometry - Algorithms and Applications, Second Edition, 2000
Jon Louis Bentley and Thomas A. Ottmann, Algorithms for Reporting and Counting Geometric Intersections, IEEE Transactions on Computers, Vol. C-28, No. 9, September 1979, pp. 643–647
Jon Louis Bentley and Derick Wood, An Optimal Worst Case Algorithm for Reporting Intersections of Rectangles, IEEE Transac |
https://en.wikipedia.org/wiki/France%20Miniature | France Miniature is a miniature park tourist attraction in Élancourt, France featuring scale models of major French landmarks and monuments in an outdoor park.
Description
France Miniature is a 5-hectare (12-acre) outdoor park in the shape of France that contains about 160 outdoor 1/30-scale models of major French monuments and landmarks. Monuments are placed in the park to correlate approximately with their real-world locations in France. Many of the models are animated, and all of the country's best known landmarks are represented (the Eiffel Tower, Versailles, Lourdes, etc.). A system of model trains runs through the park, and animated boats ply the "Atlantic Ocean" and the "Mediterranean Sea" (lagoons positioned appropriately around the perimeter of the park). Visitors walk along paved paths to visit the various models.
An indoor exhibition features extremely detailed models of several indoor scenes.
The park is closed during the winter.
France Miniature is owned by the same group (Grévin & Cie., now part of Compagnie des Alpes) that operates the Parc Astérix amusement park north of Paris.
External links
Official site
Miniature parks
Buildings and structures in Yvelines
Compagnie des Alpes
Amusement parks in France
Tourist attractions in Île-de-France
Tourist attractions in Yvelines
1991 establishments in France
Amusement parks opened in 1991 |
https://en.wikipedia.org/wiki/Strong%20secrecy | Strong secrecy is a term used in formal proof-based cryptography for making propositions about the security of cryptographic protocols. It is a stronger notion of security than syntactic (or weak) secrecy. Strong secrecy is related with the concept of semantic security or indistinguishability used in the computational proof-based approach. Bruno Blanchet provides the following definition for strong secrecy:
Strong secrecy means that an adversary cannot see any difference when the value of the secret changes
For example, if a process encrypts a message m an attacker can differentiate between different messages, since their ciphertexts will be different. Thus m is not a strong secret. If however, probabilistic encryption were used, m would be a strong secret. The randomness incorporated into the encryption algorithm will yield different ciphertexts for the same value of m.
See also
Semantic security
Notes
Cryptography |
https://en.wikipedia.org/wiki/Criticism%20of%20Google | Criticism of Google includes concern for tax avoidance, misuse and manipulation of search results, its use of others' intellectual property, concerns that its compilation of data may violate people's privacy and collaboration with the US military on Google Earth to spy on users, censorship of search results and content, and the energy consumption of its servers as well as concerns over traditional business issues such as monopoly, restraint of trade, antitrust, patent infringement, indexing and presenting false information and propaganda in search results, and being an "Ideological Echo Chamber".
Google's parent company, Alphabet Inc., is an American multinational public corporation invested in Internet search, cloud computing, and advertising technologies. Google hosts and develops a number of Internet-based services and products, and generates profit primarily from advertising through its Google Ads (formerly AdWords) program.
Google's stated mission is "to organize the world's information and make it universally accessible and useful"; this mission, and the means used to accomplish it, have raised concerns among the company's critics. Much of the criticism pertains to issues that have not yet been addressed by cyber law.
Shona Ghosh, a journalist for Business Insider, noted that an increasing digital resistance movement against Google has grown.
Tax evasion
Google cut its taxes by $3.1 billion in the period of 2007 to 2009 using a technique that moves most of its foreign profits through Ireland and The Netherlands to Bermuda. Afterwards, the company started to send £8 billion in profits a year to Bermuda. Google's income shifting—involving strategies known to lawyers as the "Double Irish" and the "Dutch Sandwich"—helped reduce its overseas tax rate to 2.4 percent, the lowest of the top five U.S. technology companies by market capitalization, according to regulatory filings in six countries.
According to economist and member of the PvdA delegation inside the |
https://en.wikipedia.org/wiki/ETSI%20Satellite%20Digital%20Radio | ETSI Satellite Digital Radio (SDR or ETSI SDR) describes a standard of satellite digital radio. It is an activity of the European standardisation organisation ETSI.
It addresses systems where a satellite broadcast directly to mobile and handheld receivers in L band or S band and is complemented by terrestrial transmitters. The broadcast content consists of multicast audio (digital radio), video (mobile TV) and data (program guide, text and graphical information, as well as off-line content). The satellite component allows geographical coverage at low cost, whereas the terrestrial component improves reception quality in built up areas. The specifications considers conditional access and Digital Rights Management.
1worldspace planned to use ETSI SDR in its new network covering Europe from 2009, but the company went defunct before it launched its service. Also Ondas Media has announced to use ETSI SDR.
The ETSI SDR is also similar to the Sirius XM Radio, the S-DMB used in South Korea for multimedia broadcasting since May 2005, the China Multimedia Mobile Broadcasting (CMMB) and the defunct MobaHo! service (2004-2009). The DVB-SH specifications, which the DVB Project has created, target similar broadcast systems as ETSI SDR.
ETSI SDR Standard
The ETSI SDR standard allows implementation of parts of such networks in an interoperable way. So far, ETSI has standardized the physical layer of the air interface (radio interface). This allows implementation of demodulators in integrated circuits. The physical layer is described by the following parts of ETSI EN 302 550:
ETSI EN 302 550-1-1 "Satellite Earth Stations and Systems (SES); Satellite Digital Radio (SDR) Systems; Part 1: Physical Layer of the Radio Interface; Sub-Part 1: Outer Physical Layer"
ETSI EN 302 550-1-2 "Satellite Earth Stations and Systems (SES); Satellite Digital Radio (SDR) Systems; Part 1: Physical Layer of the Radio Interface; Sub-Part 2: Inner Physical Layer Single Carrier Modulation"
ETSI EN 302 |
https://en.wikipedia.org/wiki/Una%20virus | Una virus is a virus species in the genus Alphavirus. According to the Baltimore classification of viruses, it is a class IV virus. It has a linear single-stranded RNA genome. Una virus is an arbovirus or arthropod-borne virus, transmitted primarily by an arthropod species.
Location and distribution
The Una virus is widely distributed in South America, where infections have been detected in mosquitoes and vertebrate hosts such as humans, birds and horses. It was first isolated in Psorophora ferox mosquitoes in the state of Pará, Brazil. The virus is widely distributed in tropical and subtropical regions of Central and South America, such as Brazil, Colombia, French Guiana, Panama, Suriname, Trinidad and Venezuela. It is the only member of the SFV complex which has activity reported in Argentina, where two strains of the virus, (Cba An 979 and Cba An 995) have been isolated from febrile or dead equines at Rio Segundo and Colonia Videla, two villages located in the province of Córdoba. The reporting of the Una virus in Argentina demonstrates an enlargement of the southern limit of the distribution of this virus group. |
https://en.wikipedia.org/wiki/De-essing | De-essing (also desibilizing) is any technique intended to reduce or eliminate the excessive prominence of sibilant consonants, such as the sounds normally represented in English by "s", "z", "ch", "j" and "sh", in recordings of the human voice. Sibilance lies in frequencies anywhere between 2 and 10 kHz, depending on the individual voice.
Causes
Excess sibilance can be caused by compression, microphone choice and technique, and even simply the way a person's mouth anatomy is shaped. Ess sound frequencies can be irritating to the ear, especially with earbuds or headphones, and interfere with an otherwise modulated and pleasant audio stream.
Process of de-essing
De-essing is a dynamic audio editing process, only working when the level of the signal in the sibilant range (the ess sound) exceeds a set threshold. De-essing temporarily reduces the level of high-frequency content in the signal when a sibilant ess sound is present. De-essing differs from equalization, which is a static change in level among many frequencies. However, equalization of the ess frequencies alone can be manipulated to reduce the level of sibilance.
There are several time- and frequency-based algorithms that can reduce sibilance or de-ess the sound. Time-domain approaches, such as bandpass filters, are more suited to real-time applications such as live radio due to less constraint on digital signal processor. Playback or offline applications incorporate methods based on fast Fourier transform (FFT).
Using a dedicated de-essing plugin
In the current digital stronghold of audio production, the most commonly used tool for reducing sibilance is a de-esser plugin. A dynamic equalizer can be used to achieve the same effects as a de-esser, however, plugin manufacturers have tailored these tools to operate efficiently within the mid-high to high frequencies.
A de-essing plugin will compress the desired signal according to the amplitude of the selected frequency as it passes over a preset threshold |
https://en.wikipedia.org/wiki/Methyl%20anthranilate | Methyl anthranilate, also known as MA, methyl 2-aminobenzoate, or carbomethoxyaniline, is an ester of anthranilic acid. Its chemical formula is C8H9NO2. It has a strong and fruity grape smell, and one of its key uses is as a flavoring agent.
Chemical properties
It is a colorless to pale yellow liquid with melting point 24 °C and boiling point 256 °C. It has a density of 1.168 g/cm3 at 20 °C. It has a refractive index of 1.583 at 589 nm of wavelength and 20 °C. It shows a light blue-violet fluorescence. It is very slightly soluble in water, and soluble in ethanol and propylene glycol. It is insoluble in paraffin oil. It is combustible, with flash point at 104 °C. Pure, it has a fruity grape smell; at 25 ppm it has a sweet, fruity, Concord grape-like smell with a musty and berry nuance.
Uses
Methyl anthranilate acts as a bird repellent. It is food-grade and can be used to protect corn, sunflowers, rice, fruit, and golf courses. Dimethyl anthranilate (DMA) has a similar effect. It is also used for part of the flavor of grape Kool-Aid. It is used for flavoring of candy, soft drinks (e.g. grape soda), fruit (e.g. Grāpples), chewing gum, and nicotine products.
Methyl anthranilate both as a component of various natural essential oils and as a synthesised aroma-chemical is used extensively in modern perfumery. It is also used to produce Schiff bases with aldehydes, many of which are also used in perfumery. In a perfumery context the most common Schiff's Base is known as aurantiol, produced by combining methyl anthranilate and hydroxycitronellal.
In organic synthesis, methyl anthranilate can be used as a source of the highly reactive aryne, benzyne. It is obtained by diazotization of the amine group using sodium nitrite which eliminates nitrogen and CO2 giving benzyne as an intermediate for Diels-Alder addition or other substitution at the ring.
Occurrence
Methyl anthranilate naturally occurs in the Concord grapes and other Vitis labrusca grapes and hybrids thereof, |
https://en.wikipedia.org/wiki/Intercept%20theorem | The intercept theorem, also known as Thales's theorem, basic proportionality theorem or side splitter theorem is an important theorem in elementary geometry about the ratios of various line segments that are created if two rays with a common starting point are intercepted by a pair of parallels. It is equivalent to the theorem about ratios in similar triangles. It is traditionally attributed to Greek mathematician Thales. It was known to the ancient Babylonians and Egyptians, although its first known proof appears in Euclid's Elements.
Formulation of the theorem
Suppose S is the common starting point of two rays and A, B are the intersections of the first ray with the two parallels, such that B is further away from S than A, and similarly C, D are the intersections of the second ray with the two parallels such that D is further away from S than C. In this configuration the following statements hold:
The ratio of any two segments on the first ray equals the ratio of the according segments on the second ray: , ,
The ratio of the two segments on the same ray starting at S equals the ratio of the segments on the parallels:
The converse of the first statement is true as well, i.e. if the two rays are intercepted by two arbitrary lines and holds then the two intercepting lines are parallel. However, the converse of the second statement is not true (see graphic for a counterexample).
Extensions and conclusions
The first two statements remain true if the two rays get replaced by two lines intersecting in . In this case there are two scenarios with regard to , either it lies between the 2 parallels (X figure) or it does not (V figure). If is not located between the two parallels, the original theorem applies directly. If lies between the two parallels, then a reflection of and at yields V figure with identical measures for which the original theorem now applies. The third statement (converse) however does not remain true for lines.
If there are more than |
https://en.wikipedia.org/wiki/Gammator | ӀA Gammator was a gamma irradiator made by the Radiation Machinery Corporation during the U.S. Atoms for Peace project of the 1950s and 1960s. The gammator was distributed by the "Atomic Energy Commission to schools, hospitals, and private firms to promote nuclear understanding." Around 120-140 Gammators were distributed throughout the U.S. and the whereabouts of several of them are unknown, although the Department of Energy has removed and destroyed many of the units.
Specifications
A Gammator weighed about 1,850 pounds and contained about 400 curies of caesium-137 in a pellet roughly the size of a pen.
Concerns
Because of the massive shielding of a Gammator, the machine is very safe when used as intended (e.g. school science experiments); according to the Los Alamos National Laboratory, it is similar to machines used to irradiate blood. However, this amount of nuclear material could pose a significant problem if used as the radioactive component in a dirty bomb. |
https://en.wikipedia.org/wiki/Tea%20tasting | Tea tasting is the process in which a trained taster determines the quality of a particular tea. Due to climatic conditions, topography, manufacturing process, and different cultivars of the Camellia sinensis plant (tea), the final product may have vastly differing flavours and appearance. A trained tester can detect these differences and ascertain the tea's quality prior to sale or possible blending.
Objectives
The taster's objectives depend on the tea's intended purpose. The qualities desired for a tea for blending with other teas can be quite different from those desired for a tea ready for drinking.
Techniques
The ISO 3103 standard describes a standardised method for brewing teas to make meaningful sensory comparisons. It is not a particularly useful standard for many teas, however, requiring a six-minute brewing time and boiling water, neither of which are recommended for green teas (usually brewed at < 90 °C and for under 3 minutes). Tasters would instead usually taste teas which have been brewed according to the producer's recommendations.
A tea taster uses a large spoon and noisily slurps the liquid into his/her mouth. This ensures that both the tea and plenty of oxygen pass over the taste receptors of the tongue, for an even taste profile. The liquid is then usually expelled into a spittoon before the taster moves to the next sample. A 'cupping set' is used for tasting tea and is always white in colour to allow examination of both liquid and the leaf. The set consists of a small cup with a lid, in which the tea leaves are placed along with the water to brew, and a small, rounded tasting cup. The tea's flavour characteristics and leaf colour, size and shape are graded using a specific language created by the tea industry. Generally speaking, once a tea's quality has been assessed, each tea company places a value on it based on market trends, availability and demand.
See also
Tea leaf grading
Federal Tea Tasters Repeal Act of 1996
Aroma wheel
ISO 31 |
https://en.wikipedia.org/wiki/Bauhaus%20Project%20%28computing%29 | The Bauhaus project is a software research project collaboration among the University of Stuttgart, the University of Bremen, and a commercial spin-off company Axivion formerly called Bauhaus Software Technologies. The Bauhaus project serves the fields of software maintenance and software reengineering.
Created in response to the problem of software rot, the project aims to analyze and recover the means and methods developed for legacy software by understanding the software's architecture. As part of its research, the project develops software tools (such as the Bauhaus Toolkit) for software architecture, software maintenance and reengineering and program understanding.
The project derives its name from the former Bauhaus art school.
History
The Bauhaus project was initiated by Erhard Ploedereder, Ph.D. and Rainer Koschke, Ph.D. at the University of Stuttgart in 1996. It was originally a collaboration between the Institute for Computer Science (ICS) of the University of Stuttgart and the Fraunhofer-Institut für Experimentelles Software Engineering (IESE), which is no longer involved.
Early versions of Bauhaus integrated and used Rigi for visualization.
The commercial spin-off Axivion was started in 2005. Research then was done at Axivion, the Institute of Software Technology, Department of Programming Languages at the University of Stuttgart as well as at the Software Engineering Group of the Faculty 03 at the University of Bremen.
Today, the academic version of the Bauhaus project and the commercially sold Axivion Suite are different products, as development at Axivion since 2010 is based on a new infrastructure which allowed Axivion to add new applications such as MISRA checking.
Bauhaus Toolkit
The Bauhaus Toolkit (or simply the "Bauhaus tool") includes a static code analysis tool for C, C++, C#, Java and Ada code. It comprises various analyses such as architecture checking, interface analysis, and clone detection. Bauhaus was originally derived from the |
https://en.wikipedia.org/wiki/The%20Jepson%20Manual | The Jepson Manual is a flora of the vascular plants that are either native to or naturalized in California. Botanists often refer to the book simply as Jepson. It is produced by the University and Jepson Herbaria, of the University of California, Berkeley. Its second edition is the basis of the online Jepson eFlora.
History
1923: Willis Linn Jepson – Manual of the Flowering Plants of California
1958, 1968: Philip Alexander Munz – A California Flora and Supplement
1993: James Craig Hickman (editor) – The Jepson Manual, Higher Plants of California (TJM93)
2012: Bruce Gregg Baldwin – The Jepson Manual: Vascular Plants of California, 2nd edition (TJM2)
2010−ongoing: The Jepson Online Interchange for California Floristics − Jepson eFlora (TJM2) – online.
Preceding works
The Jepson Manual also follows Philip A. Munz and David D. Keck in their A California Flora and Supplement of 1958 and 1968.
Like other florae, The Jepson Manual builds upon these prior publications. Except for the number of line drawings, it has more in common with Munz's 1968 book than with Jepson's 1923 book.
Editions
The first edition of The Jepson Manual was published in 1993 as The Jepson Manual: Higher Plants of California (TJM93), and was edited by James C. Hickman.
The second edition was published in 2012, as The Jepson Manual: Vascular Plants of California, Thoroughly Revised and Expanded (TJM2), and was edited by Bruce Gregg Baldwin, Douglas H. Goldman, David John Keil, Robert Patterson, and Thomas James Rosatti. The second edition features 7,601 California plant species, subspecies and varieties.
While the book is named in honor of Jepson, The Jepson Manual is not simply a new edition of Jepson's 1923 book, but a new work which Baldwin calls "the most time-consuming undertaking of my career."
Jepson eFlora
The Jepson eFlora is a taxonomic database that builds on and expands the second edition of The Jepson Manual. It describes itself as "the foremost authority on the native and natura |
https://en.wikipedia.org/wiki/Leonard%20Ornstein | Leonard Salomon Ornstein (12 November 1880 in Nijmegen, the Netherlands – 20 May 1941 in Utrecht, the Netherlands) was a Dutch physicist.
Biography
Ornstein studied theoretical physics with Hendrik Antoon Lorentz at University of Leiden. He subsequently carried out Ph.D. research under the supervision of Lorentz, concerning an application of the statistical mechanics of Gibbs to molecular problems.
In 1914, Ornstein was appointed professor of physics, as successor of Peter Debye, at University of Utrecht. Among his doctoral students was Jan Frederik Schouten. In 1922, he became director of Physical Laboratory (Fysisch Laboratorium) and extended his research interests to experimental subjects. His precision measurements concerning intensities of spectral lines brought Physical Laboratory in the international limelight.
Ornstein is also remembered for the Ornstein-Zernike theory (named after himself and Frederik Zernike) concerning correlation functions,
and the Ornstein-Uhlenbeck process (named after Ornstein and George Uhlenbeck), a stochastic process.
Together with Gilles Holst, director of Philips Research Laboratories (Philips Natuurkundig Laboratorium), he was the driving force behind establishing the Dutch Physical Society (Netherlands Physical Society, Nederlandse Natuurkundige Vereniging, NNV) in 1921. From 1939 until November 1940 he was Chairman of this Society. From 1918 until 1922 Ornstein was Chairman of the Dutch Zionist Society (Nederlandse Zionistische Vereniging). In 1929, he became member of the Royal Netherlands Academy of Arts and Sciences.
Immediately after the involvement of the Netherlands in the World War II (see Battle of the Netherlands), a friend from the United States of America, the astronomer Peter van de Kamp, offered to bring Ornstein and his family to America. However, Ornstein did not accept this offer, since, as he put it, he would not leave his laboratory in Utrecht. Owing to his Jewish heritage, Ornstein was summarily dismis |
https://en.wikipedia.org/wiki/Mm%20tree | Among Linux kernel developers, the -mm tree refers to a version of the kernel source code maintained by Andrew Morton.
The -mm kernel tree used to fill the role of Linux kernel development builds, formerly identified by odd version numbers following "2.6." (see this section on Linux kernel version numbering). New and experimental code used to find its way into a 2.6.x-mm kernel build. Historically, the -mm tree focused on new developments for the memory management part of the kernel (mm).
Occasionally, the -mm tree was overloaded with new patches, so testing it became difficult. On September 17, 2007, Morton sent a mail saying that "this just isn't working any more". The presence of the new linux-next git repository has offloaded much of the work that made mm maintenance troublesome, allowing Morton to continue to use quilt to manage his series of "mmotm" (mm of the moment) patches.
Morton includes a subset of the mmotm patches in linux-next, which has a head called "linux-next/akpm". There is also a git tree that includes the patches that appear in releases of the mm tree. To get all of the mm patches at any given time, developers still need quilt or ad hoc shell scripts to apply the full set of patches. |
https://en.wikipedia.org/wiki/Rooster%20tail | A rooster tail is a term used in fluid dynamics, automotive gear shifting, and meteorology. It is a region of commotion or turbulence within a fluid, caused by movement. In fluid dynamics, it lies directly in the wake of an object traveling within a fluid, and is accompanied by a vertical protrusion. If it occurs in a river, wise boaters upstream steer clear of its appearance. The degree of their formation can indicate the efficiency of a boat's hull design. The magnitude of these features in a boat increases with speed, while the relationship is inversely proportional for airplanes. Energetic volcanic eruptions can create rooster tail formations from their ejecta. They can form in relation to coronal loops near the Sun's surface.
In gear shifting in motor vehicles, it is the relation between the coefficient of friction and the sliding speed of the clutch. Cars can throw rooster tails in their wake and loose materials under its wheels. In meteorology, a rooster tail satellite pattern can be applied to either low or high level cloudiness, with the low cloud line seen in the wake of tropical cyclones and the high cloud pattern seen either within mare's tails or within the outflow jet of tropical cyclones.
In fluid dynamics
Rooster tails are caused by constructive interference near and to the wake of objects within a flowing fluid.
In water
A fast current of water flowing over a rock near the surface of a stream or river can create a rooster tail—such commotions at the water's surface are avoided by boaters due to the near surface obstruction. Propellers on boats can produce a rooster tail of water in their wake, in the form of a fountain which shoots into the air behind the boat. The faster a boat goes, the larger the rooster tails become. The efficiency of a boat's hull design can be judged by the magnitude of the rooster tail—larger rooster tails indicate less efficient designs. If a water skier is in tow, the skis also throw off a rooster tail. Airplanes l |
https://en.wikipedia.org/wiki/Login | In computer security, logging in (or logging on, signing in, or signing on) is the process by which an individual gains access to a computer system by identifying and authenticating themselves. The user credentials are typically some form of username and a matching password, and these credentials themselves are sometimes referred to as a login. In practice, modern secure systems often require a second factor such as email or SMS confirmation for extra security. Social login allows a user to use existing user credentials from a social networking service to sign in to or create an account on a new website.
When access is no longer needed, the user can log out, log off, sign out or sign off.
Procedure
Logging in is usually used to enter a specific page, website or application, which trespassers cannot see. Once the user is logged in, the login token may be used to track what actions the user has taken while connected to the site. Logging out may be performed explicitly by the user taking some actions, such as entering the appropriate command or clicking a website link label as such. It can also be done implicitly, such as by the user powering off their workstation, closing a web browser window, leaving a website, or not refreshing a website within a defined period.
A login page may have a return URL parameter, which specifies where to redirect back after logging in or out. For example, it is returnto= on this site.
In the case of websites that use cookies to track sessions, when the user logs out, session-only cookies from that site will usually be deleted from the user's computer. In addition, the server invalidates any associations with the session, thereby making any session-handle in the user's cookie store useless. This feature comes in handy if the user is using a public computer or a computer that is using a public wireless connection. As a security precaution, one should not rely on implicit means of logging out of a system, especially not on a public comp |
https://en.wikipedia.org/wiki/MSH2 | DNA mismatch repair protein Msh2 also known as MutS homolog 2 or MSH2 is a protein that in humans is encoded by the MSH2 gene, which is located on chromosome 2. MSH2 is a tumor suppressor gene and more specifically a caretaker gene that codes for a DNA mismatch repair (MMR) protein, MSH2, which forms a heterodimer with MSH6 to make the human MutSα mismatch repair complex. It also dimerizes with MSH3 to form the MutSβ DNA repair complex. MSH2 is involved in many different forms of DNA repair, including transcription-coupled repair, homologous recombination, and base excision repair.
Mutations in the MSH2 gene are associated with microsatellite instability and some cancers, especially with hereditary nonpolyposis colorectal cancer (HNPCC). At least 114 disease-causing mutations in this gene have been discovered.
Clinical significance
Hereditary nonpolyposis colorectal cancer (HNPCC), sometimes referred to as Lynch syndrome, is inherited in an autosomal dominant fashion, where inheritance of only one copy of a mutated mismatch repair gene is enough to cause disease phenotype. Mutations in the MSH2 gene account for 40% of genetic alterations associated with this disease and is the leading cause, together with MLH1 mutations. Mutations associated with HNPCC are broadly distributed in all domains of MSH2, and hypothetical functions of these mutations based on the crystal structure of the MutSα include protein–protein interactions, stability, allosteric regulation, MSH2-MSH6 interface, and DNA binding. Mutations in MSH2 and other mismatch repair genes cause DNA damage to go unrepaired, resulting in an increase in mutation frequency. These mutations build up over a person's life that otherwise would not have occurred had the DNA been repaired properly.
Microsatellite instability
The viability of MMR genes including MSH2 can be tracked via microsatellite instability, a biomarker test that analyzes short sequence repeats which are very difficult for cells to replicate w |
https://en.wikipedia.org/wiki/MLH1 | DNA mismatch repair protein Mlh1 or MutL protein homolog 1 is a protein that in humans is encoded by the MLH1 gene located on chromosome 3. It is a gene commonly associated with hereditary nonpolyposis colorectal cancer. Orthologs of human MLH1 have also been studied in other organisms including mouse and the budding yeast Saccharomyces cerevisiae.
Function
Variants in this gene can cause hereditary nonpolyposis colon cancer (Lynch syndrome). It is a human homolog of the E. coli DNA mismatch repair gene, mutL, which mediates protein-protein interactions during mismatch recognition, strand discrimination, and strand removal. Defects in MLH1 are associated with the microsatellite instability observed in hereditary nonpolyposis colon cancer. Alternatively spliced transcript variants encoding different isoforms have been described, but their full-length natures have not been determined.
Role in DNA mismatch repair
MLH1 protein is one component of a system of seven DNA mismatch repair proteins that work coordinately in sequential steps to initiate repair of DNA mismatches in humans. Defects in mismatch repair, found in about 13% of colorectal cancers, are much more frequently due to deficiency of MLH1 than deficiencies of other DNA mismatch repair proteins. The seven DNA mismatch repair proteins in humans are MLH1, MLH3, MSH2, MSH3, MSH6, PMS1 and PMS2. In addition, there are Exo1-dependent and Exo1-independent DNA mismatch repair subpathways.
DNA mismatches occur where one base is improperly paired with another base, or where there is a short addition or deletion in one strand of DNA that is not matched in the other strand. Mismatches commonly occur as a result of DNA replication errors or during genetic recombination. Recognizing those mismatches and repairing them is important for cells because failure to do so results in microsatellite instability] and an elevated spontaneous mutation rate (mutator phenotype). Among 20 cancers evaluated, microsatellite in |
https://en.wikipedia.org/wiki/Very%20special%20relativity | Ignoring gravity, experimental bounds seem to suggest that special relativity with its Lorentz symmetry and Poincaré symmetry describes spacetime. Surprisingly, Bogoslovsky and independently Cohen and Glashow have demonstrated that a small subgroup of the Lorentz group is sufficient to explain all the current bounds.
The minimal subgroup in question can be described as follows: The stabilizer of a null vector is the special Euclidean group SE(2), which contains T(2) as the subgroup of parabolic transformations. This T(2), when extended to include either parity or time reversal (i.e. subgroups of the orthochronous and time-reversal respectively), is sufficient to give us all the standard predictions. Their new symmetry is called very special relativity (VSR).
See also
Lorentz violation |
https://en.wikipedia.org/wiki/Cyclin%20D | Cyclin D is a member of the cyclin protein family that is involved in regulating cell cycle progression. The synthesis of cyclin D is initiated during G1 and drives the G1/S phase transition. Cyclin D protein is anywhere from 155 (in zebra mussel) to 477 (in Drosophila) amino acids in length.
Once cells reach a critical cell size (and if no mating partner is present in yeast) and if growth factors and mitogens (for multicellular organism) or nutrients (for unicellular organism) are present, cells enter the cell cycle. In general, all stages of the cell cycle are chronologically separated in humans and are triggered by cyclin-Cdk complexes which are periodically expressed and partially redundant in function. Cyclins are eukaryotic proteins that form holoenzymes with cyclin-dependent protein kinases (Cdk), which they activate. The abundance of cyclins is generally regulated by protein synthesis and degradation through APC/C- and CRL-dependent pathways.
Cyclin D is one of the major cyclins produced in terms of its functional importance. It interacts with four Cdks: Cdk2, 4, 5, and 6. In proliferating cells, cyclin D-Cdk4/6 complex accumulation is of great importance for cell cycle progression. Namely, cyclin D-Cdk4/6 complex partially phosphorylates retinoblastoma tumor suppressor protein (Rb), whose inhibition can induce expression of some genes (for example: cyclin E) important for S phase progression.
Drosophila and many other organisms only have one cyclin D protein. In mice and humans, two more cyclin D proteins have been identified. The three homologues, called cyclin D1, cyclin D2, and cyclin D3 are expressed in most proliferating cells and the relative amounts expressed differ in various cell types.
Homologues
The most studied homologues of cyclin D are found in yeast and viruses.
The yeast homologue of cyclin D, referred to as CLN3, interacts with Cdc28 (cell division control protein) during G1.
In viruses, like Saimiriine herpesvirus 2 (Herpesvirus sa |
https://en.wikipedia.org/wiki/Putrefying%20bacteria | Putrefying/decay bacteria are bacteria involved in putrefaction of living matter. Along with other decomposers, they play a critical role in recycling nitrogen from dead organisms. Putrefying bacteria also play a role in putrefaction and fermentation of proteins in the human gastrointestinal tract.
Putrefying bacteria is a broad term used to define several species of bacteria involved in decomposition and fermentation. Putrefying bacteria play a key role in decomposing and fermenting substances within the body as well as the body itself after death. Putrefaction is defined as the final step of decomposition after death. Because these bacteria play a role in decomposition after death, putrefying bacteria also play a key role in the nitrogen cycle. They deconstruct and convert substances from dead organisms so nitrifying bacteria can then convert these products into a usable form of nitrogen.
Putrefying Bacteria in the Nitrogen Cycle
The nitrogen cycle is a vital part of life, and is essential to carry out biosynthesis of nitrogen containing compounds. Nitrogen is inaccessible to most organisms unless it is fixed, and this process can only be carried out by certain classes of prokaryotes. Putrefying bacteria use amino acids or urea as an energy source to decompose dead organisms. In the process, they produce ammonium ions. Nitrifying bacteria then convert this ammonium into nitrate by oxidation, which can then be used by plants to create more proteins thus completing the nitrogen cycle. This process is called nitrification. Energy from this oxidation reaction can also be used to synthesize organic compounds in a process called chemosynthesis.
Putrefaction
Putrefaction is considered the final step following death, and is carried out mainly by anaerobic organisms from the bowel. Putrefying bacteria produce a plethora of enzymes which aid in disintegration of the body. Because of the lack of immune function within the body, these bacteria spread through blood vessel |
https://en.wikipedia.org/wiki/Cyclin-dependent%20kinase%202 | Cyclin-dependent kinase 2, also known as cell division protein kinase 2, or Cdk2, is an enzyme that in humans is encoded by the CDK2 gene. The protein encoded by this gene is a member of the cyclin-dependent kinase family of Ser/Thr protein kinases. This protein kinase is highly similar to the gene products of S. cerevisiae cdc28, and S. pombe cdc2, also known as Cdk1 in humans. It is a catalytic subunit of the cyclin-dependent kinase complex, whose activity is restricted to the G1-S phase of the cell cycle, where cells make proteins necessary for mitosis and replicate their DNA. This protein associates with and is regulated by the regulatory subunits of the complex including cyclin E or A. Cyclin E binds G1 phase Cdk2, which is required for the transition from G1 to S phase while binding with Cyclin A is required to progress through the S phase. Its activity is also regulated by phosphorylation. Multiple alternatively spliced variants and multiple transcription initiation sites of this gene have been reported. The role of this protein in G1-S transition has been recently questioned as cells lacking Cdk2 are reported to have no problem during this transition.
Dispensability in normally functioning tissue
Original cell-culture based experiments demonstrated cell cycle arrest at the G1-S transition resulting from the deletion of Cdk2. Later experiments showed that Cdk2 deletions lengthened the G1 phase of the cell cycle in mouse embryo fibroblasts. However, they still entered S phase after this period and were able to complete the remaining phases of the cell cycle. When Cdk2 was deleted in mice, the animals remained viable despite a reduction in body size. However, meiotic function of both male and female mice was inhibited. This suggests that Cdk2 is non-essential for the cell cycle of healthy cells, but essential for meiosis and reproduction. Cells in Cdk2 knockout mice likely undergo fewer divisions, contributing to the reduction in body size. Germ cells also st |
https://en.wikipedia.org/wiki/Langerin | Langerin (CD207) is a type II transmembrane protein which is encoded by the CD207 gene in humans. It was discovered by scientists Sem Saeland and Jenny Valladeau as a main part of Birbeck granules. Langerin is C-type lectin receptor on Langerhans cells (LCs) and in mice also on dermal interstitial CD103+ dendritic cells (DC) and on resident CD8+ DC in lymph nodes.
Structure
Langerin consists of a relatively short intracellular domain and an extracellular domain which consists of a neck-region and a carbohydrate recognition domain (CRD). The intracellular part contains a proline-rich domain (PRD). The neck region consists of alpha-helixes and mediates a formation of langerin homotrimers via a coiled-coil interaction. The homotrimers formation increases avidity and specificity of the antigen.
The CRD of langerin is similar to CRDs of other C-type lectins. It contains an EPN motif – a Glu-Pro-Asn rich region. The CRD is divided into two lobes by 2 anti-parallel beta-sheets. The upper lobe creates the primary Ca2+ dependent carbohydrates binding site. In contrast to other lectins, for instance, DC-SIGN / DC-SIGNR and MBP, langerin has only one binding site for Ca2+. In the upper lobe, there have been discovered two other binding sites by a crystallization method. These sites are not dependent on Ca2+ and their relation to the primary binding site is not completely understood. All the binding sites are flanked by positively charged amino acids (K299 and K313) which enable binding of negatively charged sulphated carbohydrates. These amino acids are not present in DC-SIGN.
Function
Langerin is expressed in LCs which are located in the epidermis and in vaginal and oral mucosa. LCs are immune cells closely related to macrophages, but by their function, they are more like conventional dendritic cells (cDCs). Langerin recognizes and binds carbohydrates, such as mannose, fucose and N-acetylglucosamine. Thus, LCs may react against pathogens such as HIV-1, Mycobacterium lepr |
https://en.wikipedia.org/wiki/Tip-speed%20ratio | The tip-speed ratio, λ, or TSR for wind turbines is the ratio between the tangential speed of the tip of a blade and the actual speed of the wind, . The tip-speed ratio is related to efficiency, with the optimum varying with blade design. Higher tip speeds result in higher noise levels and require stronger blades due to larger centrifugal forces.
The tip speed of the blade can be calculated as times R, where is the rotational speed of the rotor in radians/second, and R is the rotor radius in metres. Therefore, we can also write:
where is the wind speed in metres/second at the height of the blade hub.
Cp–λ curves
The power coefficient, is a quantity that expresses what fraction of the power in the wind is being extracted by the wind turbine. It is generally assumed to be a function of both tip-speed ratio and pitch angle. Below is a plot of the variation of the power coefficient with variations in the tip-speed ratio when the pitch is held constant:
The case for variable speed wind turbines
Originally, wind turbines were fixed speed. This has the benefit that the rotor speed in the generator is constant, thus the frequency of the AC voltage is fixed. This allows the wind turbine to be directly connected to a transmission system. However, from the figure above, we can see that the power coefficient is a function of the tip-speed ratio. By extension, the efficiency of the wind turbine is a function of the tip-speed ratio.
Ideally, one would like to have a turbine operating at the maximum value of at all wind speeds. This means that as the wind speed changes, the rotor speed must change to such that . A wind turbine with a variable rotor speed is called a variable speed wind turbine. Whilst this does mean that the wind turbine operates at or close to for a range of wind speeds, the frequency of the AC voltage generator will not be constant. This can be seen in the following equation:
where is the rotor angular speed, is the frequency of the AC volta |
https://en.wikipedia.org/wiki/Invariant%20factor | The invariant factors of a module over a principal ideal domain (PID) occur in one form of the structure theorem for finitely generated modules over a principal ideal domain.
If is a PID and a finitely generated -module, then
for some integer and a (possibly empty) list of nonzero elements for which . The nonnegative integer is called the free rank or Betti number of the module , while are the invariant factors of and are unique up to associatedness.
The invariant factors of a matrix over a PID occur in the Smith normal form and provide a means of computing the structure of a module from a set of generators and relations.
See also
Elementary divisors |
https://en.wikipedia.org/wiki/Trimean | In statistics the trimean (TM), or Tukey's trimean, is a measure of a probability distribution's location defined as a weighted average of the distribution's median and its two quartiles:
This is equivalent to the average of the median and the midhinge:
The foundations of the trimean were part of Arthur Bowley's teachings, and later popularized by statistician John Tukey in his 1977 book which has given its name to a set of techniques called exploratory data analysis.
Like the median and the midhinge, but unlike the sample mean, it is a statistically resistant L-estimator with a breakdown point of 25%. This beneficial property has been described as follows:
Efficiency
Despite its simplicity, the trimean is a remarkably efficient estimator of population mean. More precisely, for a large data set (over 100 points) from a symmetric population, the average of the 20th, 50th, and 80th percentile is the most efficient 3-point L-estimator, with 88% efficiency. For context, the best single point estimate by L-estimators is the median, with an efficiency of 64% or better (for all n), while using two points (for a large data set of over 100 points from a symmetric population), the most efficient estimate is the 29% midsummary (mean of 29th and 71st percentiles), which has an efficiency of about 81%. Using quartiles, these optimal estimators can be approximated by the midhinge and the trimean. Using further points yield higher efficiency, though it is notable that only three points are needed for very high efficiency.
See also
Truncated mean
Interquartile mean |
https://en.wikipedia.org/wiki/Coronary%20ligament%20of%20the%20knee | The coronary ligaments of the knee (also known as meniscotibial ligaments) are portions of the joint capsule which connect the inferior edges of the fibrocartilaginous menisci to the periphery of the tibial plateaus.
Structure
The coronary ligaments of the knee are continuous with the joint capsule and the menisci.
Function
The coronary ligaments function to connect parts of the outside, inferior edges of the medial and lateral menisci to the joint capsule of the knee.
The medial meniscus also has firm attachments laterally to the intercondylar area of the tibia and medially to the tibial collateral ligament.
The lateral meniscus has firm attachments medially to the intercondylar area via the ends of the meniscus, and posteromedially via the posterior meniscofemoral ligament, which attaches the posterior limb of the meniscus to the posterior cruciate ligament and medial femoral condyle. The lateral meniscus is not directly connected to the fibular collateral ligament, and is thus more movable than the medial meniscus.
Additional images |
https://en.wikipedia.org/wiki/Vagal%20tone | Vagal tone is activity of the vagus nerve, the 10th cranial nerve and a fundamental component of the parasympathetic branch of the autonomic nervous system. This branch of the nervous system is not under conscious control and is largely responsible for the regulation of several body compartments at rest. Vagal activity results in various effects, including: heart rate reduction, vasodilation/constriction of vessels, glandular activity in the heart, lungs, and digestive tract, liver, immune system regulation as well as control of gastrointestinal sensitivity, motility and inflammation.
In this context, tone specifically refers to the continual nature of baseline parasympathetic action that the vagus nerve exerts. While baseline vagal input is constant, the degree of stimulation it exerts is regulated by a balance of inputs from sympathetic and parasympathetic divisions of the autonomic nervous system, with parasympathetic activity generally being dominant. Vagal tone is frequently used to assess heart function, and is also useful in assessing emotional regulation and other processes that alter, or are altered by, changes in parasympathetic activity.
Measurements of vagal tone can be performed by means of either invasive or noninvasive procedures. Invasive procedures are in the minority and include vagus nerve stimulation by specific manual, breathing or electrical techniques. Noninvasive techniques mainly rely on the investigation of heart rate and heart rate variability.
Noninvasive vagal tone quantification
In most cases, vagal tone is not measured directly. Instead the processes affected by the vagus nerve – specifically heart rate and heart rate variability – are measured and used as a surrogate for vagal tone. Increased vagal tone (and thus vagal action) is generally associated with a lower heart rate and increased heart rate variability. However, during graded orthostatic tilt, vagal tone withdrawal is an indirect indicator of cardiovascular fitness.
Vaga |
https://en.wikipedia.org/wiki/Data-Link%20Switching | Data-Link Switching (DLSw) is a tunneling protocol designed to tunnel unroutable, non-IP based protocols such as IBM Systems Network Architecture (SNA) and NBF over an IP network.
DLSw was initially documented in IETF RFC 1434 in 1993. In 1995 it was further documented in the IETF RFC 1795. DLSw version 2 was presented in 1997 in IETF RFC 2166 as an improvement to RFC 1795. Cisco Systems has its own proprietary extensions to DLSw in DLSw+. According to Cisco, DLSw+ is 100% IETF RFC 1795 compliant but includes some proprietary extensions that can be used when both devices are Cisco.
Some organisations are starting to replace DLSw tunneling with the more modern Enterprise Extender (EE) protocol which is a feature of IBM APPN on z/OS systems. Microsoft refers to EE as IPDLC. Enterprise Extender uses UDP traffic at the transport layer rather than the network layer.
Cisco deploy Enterprise Extender on their hardware via the IOS feature known as SNAsW (SNA Switch).
See also
Microsoft Host Integration Server
Synchronous Data Link Control
Systems Network Architecture |
https://en.wikipedia.org/wiki/Action%20description%20language | In artificial intelligence, action description language (ADL) is an automated planning and scheduling system in particular for robots. It is considered an advancement of STRIPS. Edwin Pednault (a specialist in the field of data abstraction and modelling who has been an IBM Research Staff Member in the Data Abstraction Research Group since 1996) proposed this language in 1987. It is an example of an action language.
Origins
Pednault observed that the expressive power of STRIPS was susceptible to being improved by allowing the effects of an operator to be conditional. This is the main idea of ADL-A, which is roughly the propositional fragment of the ADL proposed by Pednault, with ADL-B an extension of -A. In the -B extension, actions can be described with indirect effects by the introduction of a new kind of propositions: ”static laws". A third variation of ADL is ADL-C which is similar to -B, in the sense that its propositions can be classified into static and dynamic laws, but with some more particularities.
The sense of a planning language is to represent certain conditions in the environment and, based on these, automatically generate a chain of actions which lead to a desired goal. A goal is a certain partially specified condition. Before an action can be executed its preconditions must be fulfilled; after the execution the action yields effects, by which the environment changes. The environment is described by means of certain predicates, which are either fulfilled or not.
Contrary to STRIPS, the principle of the open world applies with ADL: everything not occurring in the conditions is unknown (Instead of being assumed false). In addition, whereas in STRIPS only positive literals and conjunctions are permitted, ADL allows negative literals and disjunctions as well.
Syntax of ADL
An ADL schema consists of an action name, an optional parameter list and four optional groups of clauses labeled Precond, Add, Delete and Update.
The Precond group is a list of fo |
https://en.wikipedia.org/wiki/Video%20standards%20converter | A video standards converter is a video device that converts NTSC to PAL and/or PAL to NTSC.
The PAL TV signals may be transcoded to or from SECAM.
Video standards converters are primarily used so television shows can be viewed in nations with different video standards.
With the use of high-definition television, new digital video standards converters came on the market. Some were down converters only, HDTV to PAL or NTSC. Others could both up and down convert: HDTV to standard definition: PAL or NTSC and vice versa.
History
Converters are needed because NTSC uses 30 frames (pictures) per second and PAL uses 25 frames per second.
First video standards converters were analog. That is a special professional video camera that used a video camera tube would be pointed at a cathode ray tube video monitor. Both the Camera and the monitor could be switched to either NTSC or PAL, to convert both ways. Robert Bosch GmbH's Fernseh Division made a large three rack analog video standards converter, Model NC 56 P 40. These were the high-end converters of the 1960s and 1970s. Image Transform in Universal City, CA used the Fernseh converter and in the 1980s made their own a custom digital converter. This was also a larger 3 rack device. As digital memory size became larger in smaller packages converters became the size of a microwave oven. Today one can buy a very small converter for home use.
See also
Reverse Standards Conversion
Scan conversion
Television standards conversion
External links
Web site
Video standards |
https://en.wikipedia.org/wiki/Compressed%20fluid | A compressed fluid (also called a compressed or unsaturated liquid, subcooled fluid or liquid) is a fluid under mechanical or thermodynamic conditions that force it to be a liquid.
At a given pressure, a fluid is a compressed fluid if it is at a temperature lower than the saturation temperature. This is the case, for example, for liquid water at atmospheric pressure and room temperature. In a plot that compares pressure and specific volume (commonly called a p-v diagram), compressed fluid is the state to the left of the saturation curve.
Conditions that cause a fluid to be compressed include:
Specific volume and enthalpy inferior to that of a saturated liquid;
Temperature below the saturation temperature;
Pressure above the saturation pressure.
The term compressed liquid emphasizes that the pressure is greater than the saturation pressure for the given temperature. Compressed liquid properties are relatively independent of pressure. |
https://en.wikipedia.org/wiki/Subgradient%20method | Subgradient methods are iterative methods for solving convex minimization problems. Originally developed by Naum Z. Shor and others in the 1960s and 1970s, subgradient methods are convergent when applied even to a non-differentiable objective function. When the objective function is differentiable, sub-gradient methods for unconstrained problems use the same search direction as the method of steepest descent.
Subgradient methods are slower than Newton's method when applied to minimize twice continuously differentiable convex functions. However, Newton's method fails to converge on problems that have non-differentiable kinks.
In recent years, some interior-point methods have been suggested for convex minimization problems, but subgradient projection methods and related bundle methods of descent remain competitive. For convex minimization problems with very large number of dimensions, subgradient-projection methods are suitable, because they require little storage.
Subgradient projection methods are often applied to large-scale problems with decomposition techniques. Such decomposition methods often allow a simple distributed method for a problem.
Classical subgradient rules
Let be a convex function with domain . A classical subgradient method iterates
where denotes any subgradient of at , and is the iterate of . If is differentiable, then its only subgradient is the gradient vector itself.
It may happen that is not a descent direction for at . We therefore maintain a list that keeps track of the lowest objective function value found so far, i.e.
Step size rules
Many different types of step-size rules are used by subgradient methods. This article notes five classical step-size rules for which convergence proofs are known:
Constant step size,
Constant step length, , which gives
Square summable but not summable step size, i.e. any step sizes satisfying
Nonsummable diminishing, i.e. any step sizes satisfying
Nonsummable diminishing step leng |
https://en.wikipedia.org/wiki/Zoid | In botany, a zoid or zoïd is a reproductive cell that possesses one or more flagella, and is capable of independent movement. Zoid can refer to either an asexually reproductive spore or a sexually reproductive gamete. In sexually reproductive gametes, zoids can be either male or female depending on the species. For example, some brown alga (Phaeophyceae) reproduce by producing multi-flagellated male and female gametes that recombine to form the diploid sporangia. Zoids are primarily found in some protists, diatoms, green alga, brown alga, non-vascular plants, and a few vascular plants (ferns, cycads, and Ginkgo biloba). The most common classification group that produces zoids is the heterokonts or stramenopiles. These include green alga, brown alga, oomycetes, and some protists. The term is generally not used to describe motile, flagellated sperm found in animals. Zoid is also commonly confused for zooid which is a single organism that is part of a colonial animal.
Diversity of zoids
A zoid contains one or more flagella for motility. In the various species that produce zoids, there is a high level of diversity in the number of flagella produced. The heterokonts generally produce zoids with 2 flagella, while the Ginkgo biloba produce zoids with tens of thousands of flagella. The position of the flagella and the arrangement of the microtubules varies among species as well. The following sections will briefly outline general characteristics of the zoids found in each subset as well as provide specific examples.
Zoids in heterokonts
Heterokonts are a diverse group of eukaryotic organisms that include diatoms, green algae, and brown algae. The defining characteristic of this group is their bi-flagellate, motile sperm (zoid). The two flagella are most commonly positioned apically or sub-apically depending on the type of heterokont. One flagella, the tinsel flagella, is generally longer and covered with bristles. The other flagella is typically shorter, poten |
https://en.wikipedia.org/wiki/Unique%20Feature%20Identifier | Unique Feature Identifier or UFI, also known as “UF” is a geocode used for cities, towns, villages, and other geographic features. Generally, these are Static Unique Feature Identifiers (SUFI).
Notes
Geocodes |
https://en.wikipedia.org/wiki/Amstrad%20PC2286 | The Amstrad PC2286 was launched 1989. The 2000 series launched as a professional follow on to the PC1512/1640.
The 2000 series consisted of three models: 2086 (8086), 2286 (80286) and 2386 (80386DX). The series used a plastic case similar to 1512–1640, but this time the main computer unit had its own power supply unit built in. The machine's BIOS setting were battery-backed, using four AA batteries mounted on top of the base unit.
The 2286 came with 3.5" floppy drives as standard, with side port enabling an external 5¼" disk drive to be connected. The package contained one of a range of monitors. Screen were 12" and 14" in VGA monochrome and colour.
Specifications
Processor: 16-bit Intel 80286 CPU @ 12.5 MHz
Memory: 1 MB/4 MB RAM
Hard Disk: 40 MB
Graphics: VGA adaptor supporting MDA, CGA, Hercules, EGA, MCGA and EVGA
I/O: Serial, parallel, 5.25 inch or 3.5 inch FDD, mouse
Operating system: MS-DOS 4.01, Microsoft Windows 2.1 and Microsoft GW-BASIC |
https://en.wikipedia.org/wiki/Finjan%20Holdings | Finjan Holdings (Finjan) is a company that focuses on the licensing of intellectual property. Finjan claims to own patented technology used in enterprise web security tools. Formerly a publicly traded company on NASDAQ (FNJN), it was acquired by the Fortress Investment Group in 2020.
Finjan has filed a large number of lawsuits against leading software security companies asserting its patents including against: Cisco, Palo Alto Networks, Symantec, Blue Coat Systems, Sophos, Trend Micro, ESET, Bitdefender, Check Point, Qualys, Rapid7, Fortinet and others. As such, Finjan has been named a patent troll.
The original hardware and software divisions of Finjan were acquired by M86 Security in 2009. Finjan continues to hold patents for various Web security technologies and licenses these patents to Trustwave (formerly M86) among others. Finjan's commitment to innovation in the security space continues through its investments which have culminated in the recent launch of Finjan's consulting services business, CybeRisk development of mobile applications for the consumer through its subsidiary Finjan Mobile and the incubation of up-and-coming technology startups pioneering a new generation of security technologies through the company's investment in Jerusalem Venture Partners (JVP) Fund VII's Cyber Labs, having invested alongside companies like Cisco and other technology companies. The company is headquartered in East Palo Alto, California.
History
Finjan was founded in 1997 by Shlomo Touboul, a serial entrepreneur who founded his first company, Shani Computers, in 1985 and sold it to Intel in 1994. He then worked for Intel for a while, before starting Finjan. In 1998 Touboul decided to bring in an experienced seasoned CEO, who would be able to develop and grow the company more quickly, he then left to start his own venture capital fund.
In 2001, the company ran into financial difficulties and Touboul was asked by the board of directors to rejoin the company as CEO. Toubou |
https://en.wikipedia.org/wiki/Very-low-drag%20bullet | A very-low-drag bullet (VLD) is primarily a small arms ballistics development of the 1980s–1990s, driven by the design objective of bullets with higher degrees of accuracy and kinetic efficiency, especially at extended ranges. To achieve this, the projectile must minimize air resistance in flight. Usage has been greatest from military snipers and long-range target shooters, including F-class and benchrest competitors, but hunters have also benefited. Most VLD bullets are used in rifles. VLD bullets typically have a ballistic coefficient greater than 0.5, although the threshold is undefined.
Bullets with a lower drag coefficient decelerate less rapidly. A low drag coefficient flattens the projectile's trajectory and also markedly decreases the lateral drift caused by crosswinds. The higher velocity of bullets with low drag coefficients means they retain more kinetic energy.
Development
VLD bullets are long and heavy for their diameter, to achieve a high sectional density. Development of VLD bullets has focused on reducing a form factor defined as the sectional density divided by the ballistic coefficient. Form factor can be minimized by:
bullet nose design incorporating a secant ogive, tangent ogive, Von Kármán ogive or Sears-Haack profile
the use of tapered bullet heels, also known as boat-tails
a cavity or hollow in the bullet nose (hollow point) to reduce weight while shifting the projectile's centre of gravity rearwards to improve stability with concentric and coincident centre of pressure and centre of mass
The resulting projectile should be streamlined for easier passage through the air. Consistency in bullet production, allied to consistency in the assembly of cartridges (quality control) should give excellent shot-to-shot consistency.
The principles of bullet design and flight are classically set out in Franklin Ware Mann's The Bullet's Flight From Powder to Target: Ballistics of Small Arms.
Mono-metal designs
Machining mono-metal bullets (coreless bu |
https://en.wikipedia.org/wiki/AMELX | Amelogenin, X isoform is a protein that in humans is encoded by the AMELX gene. AMELX is located on the X chromosome and encodes a set of isoforms of amelogenin by alternative splicing. Amelogenin is an extracellular matrix protein involved in the process of amelogenesis, the formation of enamel on teeth.
Function
AMELX is involved in biomineralization during tooth enamel development. The AMELX gene encodes for the structural modeling protein, amelogenin, which works with other amelogenesis-related proteins to direct the mineralisation of enamel. This process involves the organization of enamel rods, the basic unit of tooth enamel, as well as the inclusion and growth of hydroxyapatite crystals.
Clinical significance
Mutations in AMELX result in amelogenesis imperfecta. It has been shown that mice with a knocked-out AMELX gene will present disorganized and hypoplastic enamel.
See also
AMELY |
https://en.wikipedia.org/wiki/International%20Conference%20on%20Software%20Reuse | The International Conference on Software Reuse (ICSR), is the primary scientific conference on software reuse, domain analysis, and domain engineering.
ICSR includes software reuse researchers, practitioners, and managers. The conference provides an archival source for important reuse papers. The conference is also meant to provide reuse information and education to practitioners, and to be an ongoing platform for technology transfer.
Software reusability, the use of knowledge or artifacts from existing systems to build new ones, is a key software engineering technology important both to engineers and managers. Reuse research has been very active. Many organizations have reported reuse successes, yet there are still important research issues in systematic reuse. There is a need for reuse solutions that can be applied across domain and organization boundaries. The conference consists of technical presentations, parallel working groups, plenary sessions, demonstrations, and tutorials.
Topics include reuse metrics, case studies and experiments, copyright and legal issues, current issues in reuse libraries, distributed components, formal methods, design and validation of components, domain analysis and engineering, generators, and Integration frameworks.
List of conferences: |
https://en.wikipedia.org/wiki/Gene%20nomenclature | Gene nomenclature is the scientific naming of genes, the units of heredity in living organisms. It is also closely associated with protein nomenclature, as genes and the proteins they code for usually have similar nomenclature. An international committee published recommendations for genetic symbols and nomenclature in 1957. The need to develop formal guidelines for human gene names and symbols was recognized in the 1960s and full guidelines were issued in 1979 (Edinburgh Human Genome Meeting). Several other genus-specific research communities (e.g., Drosophila fruit flies, Mus mice) have adopted nomenclature standards, as well, and have published them on the relevant model organism websites and in scientific journals, including the Trends in Genetics Genetic Nomenclature Guide. Scientists familiar with a particular gene family may work together to revise the nomenclature for the entire set of genes when new information becomes available. For many genes and their corresponding proteins, an assortment of alternate names is in use across the scientific literature and public biological databases, posing a challenge to effective organization and exchange of biological information. Standardization of nomenclature thus tries to achieve the benefits of vocabulary control and bibliographic control, although adherence is voluntary. The advent of the information age has brought gene ontology, which in some ways is a next step of gene nomenclature, because it aims to unify the representation of gene and gene product attributes across all species.
Relationship with protein nomenclature
Gene nomenclature and protein nomenclature are not separate endeavors; they are aspects of the same whole. Any name or symbol used for a protein can potentially also be used for the gene that encodes it, and vice versa. But owing to the nature of how science has developed (with knowledge being uncovered bit by bit over decades), proteins and their corresponding genes have not always been discov |
https://en.wikipedia.org/wiki/List%20of%20computer%20simulation%20software | The following is a list of notable computer simulation software.
Free or open-source
Advanced Simulation Library - open-source hardware accelerated multiphysics simulation software.
ASCEND - open-source equation-based modelling environment.
Cantera - chemical kinetics package.
Celestia - a 3D astronomy program.
CP2K - Open-source ab-initio molecular dynamics program.
DWSIM - an open-source CAPE-OPEN compliant chemical process simulator.
EFDC Explorer - open-source for processing of the Environmental Fluid Dynamics Code (EFDC).
Elmer - an open-source multiphysical simulation software for Windows/Mac/Linux.
Facsimile - a free, open-source discrete-event simulation library.
FlightGear - a free, open-source atmospheric and orbital flight simulator with a flight dynamics engine (JSBSim) that is used in a 2015 NASA benchmark to judge new simulation code to space industry standards.
FreeFem++ - Free, open-source, multiphysics Finite Element Analysis (FEA) software.
Freemat - a free environment for rapid engineering, scientific prototyping and data processing using the same language as MATLAB and GNU Octave.
Gekko - simulation software in Python with machine learning and optimization
GNU Octave - an open-source mathematical modeling and simulation software very similar to using the same language as MATLAB and Freemat.
JModelica.org is a free and open source software platform based on the Modelica modeling language.
Mobility Testbed - an open-source multi-agent simulation testbed for transport coordination algorithms.
NEST - open-source software for spiking neural network models.
NetLogo - an open-source multi-agent simulation software.
ns-3 - an open-source network simulator.
OpenFOAM - open-source software used for computational fluid dynamics (or CFD).
OpenModelica - an open source modeling environment based on Modelica the open standard for modeling software.
Open Source Physics - an open-source Java software project for teaching and studying physic |
https://en.wikipedia.org/wiki/RCOS%20%28computer%20sciences%29 | rCOS stands for refinement of object and component systems. It is a formal method providing component-based model-driven software development.
Overview
rCOS was originally developed by He Jifeng, Zhiming Liu and Xiaoshan Li at UNU-IIST in Macau, and consists of a unified multi-view modeling notation with a theory of relational semantic and graph-based operational semantics, a refinement calculus and tool support for model construction, model analysis and verification, and model transformations. Model transformations automate refinement rules and design patterns and generate conditions as proof obligations. rCOS support multiple dimensional modeling: models at different levels of abstraction related by refinement relations, hierarchy of compositions of components, and models of different views of the system (interaction protocols of components, reactive behaviors of components, data functionality, and class structures and data types). Components are composed and integrated based on their models of interfaces to support third party composition.
Bibliography
Ruzhen Dong, Johannes Faber, Wei Ke, Zhiming Liu: "rCOS: Defining Meanings of Component-Based Software Architectures". Unifying Theories of Programming and Formal Engineering Methods – ICTAC Training School on Software Engineering 2013, LNCS 8050: 1-66, Springer (2013)
Wei Ke, Xiaoshan Li, Zhiming Liu, Volker Stolz: "rCOS: a formal model-driven engineering method for component-based software". Frontiers of Computer Science in China 6(1): 17-39 (2012)
Zhiming Liu, Charles Morisset and Volker Stolz. "rCOS: Theory and Tool for Component-Based Model Driven Development, Keynote at FSEN09", Technical Report 406, UNU-IIST, P.O. Box 3058, Macau, February 2009.
Zhenbang Chen, Zhiming Liu, Ander P. Ravn and Volker Stolz (2009). "Refinement and Verification in Component-Based Model Driven Design". UNU-IIST Research Report 381. Science of Computer Programming, 74(4):168-196, 2009.
Liang Zhao, Xiaojian Liu, Zhiming Liu |
https://en.wikipedia.org/wiki/Pleckstrin | Pleckstrin is a protein found in platelets. The name derives from platelet and leukocyte C kinase substrate and the KSTR string of amino acids.
It is the source of the name pleckstrin homology domain.
External links
Proteins |
https://en.wikipedia.org/wiki/Zhiming%20Liu%20%28computer%20scientist%29 | Zhiming Liu (, born 10 October 1961, Hebei, China) is a computer scientist. He studied mathematics in Luoyang, Henan in China and obtained his first degree in 1982. He holds a master's degree in Computer Science from the Institute of Software of the Chinese Academy of Sciences (1988), and a PhD degree from the University of Warwick (1991). His PhD thesis was on Fault-Tolerant Programming by Transformations.
After his PhD, Zhiming Liu worked as a guest scientist at the Department of Computer Science, Technical University of Denmark, Lyngby in 1991–1992. Then he returned to the University of Warwick and worked as a postdoctoral research fellow on formal techniques in real-time and fault-tolerant systems till October 1994 when he became a university lecturer in computer science at the University of Leicester (UK). He worked at UNU-IIST during 2002–2013 at UNU-IIST as research fellow and senior research fellow. He joined Birmingham City University (UK) in October 2013 as the Professor of Software Engineering. In 2016, he moved to a new professorial post at Southwest University in Chongqing, China, with funding through the Thousand Talents Program.
Zhiming Liu's main research interest is in the areas of formal methods of computer systems design, including real-time systems, fault-tolerant systems, object-oriented and component-based systems. His research results have been published in mainstream journals and conferences. His joint work with Mathai Joseph work on fault tolerance gives a formal model that defines precisely the notions of fault, error, failure and fault-tolerance, and their relations. It also gives the properties that models of fault-affected programs and fault-tolerant programs in terms of model transformations. They proposed a design process for fault-tolerant systems from requirement specifications and analysis, fault environment identification and analysis, specification of fault-affected design and verification of fault-tolerance for satisfaction of |
https://en.wikipedia.org/wiki/Hirst%20Research%20Centre | The Hirst Research Centre, also known as the GEC Hirst Research Centre or GEC Research Laboratories, was established in 1919 at Wembley, Middlesex, by the General Electric Company.
History
Formally opened in 1923, the site at East Lane, Wembley was one of the first specialised industrial research laboratories to be built in Britain. The centre was named after Hugo Hirst, one of the founders of the company that would become the General Electric Company.
One of the centre's most famous achievements was the production of the cavity magnetron during World War II, the concept of which was established by Randall and Boot working at Birmingham University. Staff of the centre were also important in developing radars for use during the war. The 60 m radio mast at the back of the building became, along with Wembley Stadium, one of the landmarks of the area. Hirst was instrumental in setting up the National Grid system which provides power to the whole of the UK. The centre also worked on the design of electrical power systems for the British railway network.
In the 1990s the organisation moved to Borehamwood, Hertfordshire. After GEC left the Wembley site, it was used as the set for some scenes of the 1995 film The Young Poisoner's Handbook.
Notable Hirst employees and scientists
Clifford Paterson was the organisation's first director, and held that position until his death in 1948. Others working there included:
Derek Abbott
Jean Bacon
David Bevan
Colin Cherry
Robert James Clayton
Paul Hendricks
Cyril Hilsum
Daryl E. Hooper
Daniel McCaughan
Sanjay Jha
Bernard de Neumann
Clifford Copland Paterson
Michael Pepper
Derek Roberts
Bruce Robertson
Michael John Smith
Boris Townsend
Ian Robert Young
See also
Marconi Research Centre
GEC-Marconi scientist deaths conspiracy theory |
https://en.wikipedia.org/wiki/Alphachrysovirus | Alphachrysovirus is a genus of double-stranded RNA viruses. It is one of two genera in the family Chrysoviridae. They infect fungi, in particular Penicillium. Their name is derived from the Greek word chrysos which means yellow-green. There are 20 species in this genus.
Structure
Viruses in the genus Alphachrysovirus are non-enveloped, with icosahedral geometries, and T=1, T=2 symmetry. The diameter is around 35–40 nm.
Genome
Genomes are linear double-stranded RNA which is around 12.5 kbp in length. The genome codes for four proteins. The genome has three double stranded RNA segments. All have extended highly conserved terminal sequences at both ends.
Life cycle
Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of transcription. The virus exits the host cell by cell to cell movement. Fungi serve as the natural host.
Taxonomy
The following species are recognized:
Amasya cherry disease associated chrysovirus
Anthurium mosaic-associated chrysovirus
Aspergillus fumigatus chrysovirus
Brassica campestris chrysovirus
Chrysothrix chrysovirus 1
Colletotrichum gloeosporioides chrysovirus
Cryphonectria nitschkei chrysovirus 1
Fusarium oxysporum chrysovirus 1
Helminthosporium victoriae virus 145S
Isaria javanica chrysovirus
Macrophomina phaseolina chrysovirus
Penicillium brevicompactum virus
Penicillium chrysogenum virus
Penicillium cyaneofulvum virus
Persea americana chrysovirus
Raphanus sativus chrysovirus
Salado alphachrysovirus
Shuangao insect-associated chrysovirus
Verticillium dahliae chrysovirus 1
Zea mays chrysovirus 1 |
https://en.wikipedia.org/wiki/Transcription%20factor%20II%20H | Transcription factor II H (TFIIH) is an important protein complex, having roles in transcription of various protein-coding genes and DNA nucleotide excision repair (NER) pathways. TFIIH first came to light in 1989 when general transcription factor-δ or basic transcription factor 2 was characterized as an indispensable transcription factor in vitro. This factor was also isolated from yeast and finally named TFIIH in 1992.
TFIIH consists of ten subunits, 7 of which (ERCC2/XPD, ERCC3/XPB, GTF2H1/p62, GTF2H4/p52, GTF2H2/p44, GTF2H3/p34 and GTF2H5/TTDA) form the core complex. The cyclin-activating kinase-subcomplex (CDK7, MAT1, and cyclin H) is linked to the core via the XPD protein. Two of the subunits, ERCC2/XPD and ERCC3/XPB, have helicase and ATPase activities and help create the transcription bubble. In a test tube, these subunits are only required for transcription if the DNA template is not already denatured or if it is supercoiled.
Two other TFIIH subunits, CDK7 and cyclin H, phosphorylate serine amino acids on the RNA polymerase II C-terminal domain and possibly other proteins involved in the cell cycle. Next to a vital function in transcription initiation, TFIIH is also involved in nucleotide excision repair.
History of TFIIH
Before TFIIH identified it, it had several names : this factor first in 1989 isolated from liver of rat known that time as factor transcription delta it also, isolated from cancer cell known that time as Basic transcription factor 2, Also, it is isolated from yeast known transcription factor B. Finally, in 1992 known as TFIIH.
Structure of TFIIH
TFIIH is a ten‐subunit complex; seven of these subunits comprise the “core” whereas three comprise the dissociable “CAK” (CDK Activating Kinase) module. The core consists of subunits XPB, XPD, p62, p52, p44, p34 and p8 while CAK is composed of CDK7, cyclin H, and MAT1.
Functions
General function of TFIIH:
Initiation transcription of protein- coding gene.
DNA nucleotide repairing.
(N |
https://en.wikipedia.org/wiki/DNS%20management%20software | DNS management software is computer software that controls Domain Name System (DNS) server clusters. DNS data is typically deployed on multiple physical servers. The main purposes of DNS management software are:
to reduce human error when editing complex and repetitive DNS data
to reduce the effort required to edit DNS data
to validate DNS data before it is published to the DNS servers
to automate the distribution of DNS data
Background
In 1995, there were only 70,000 domains in existence. The way to register them was by email and the way to publish them was BIND. By mid-1997, the domain count was 1.3 million. As the number of domains and internet hosts skyrocketed, so too did the quantity of DNS data and the time required to manage it. Sysadmins responded by writing Perl or Shell scripts that helped automate DNS changes. These scripts were mostly in-house tools. The closest thing to widely available DNS management software was the BIND module in webmin, which provided web tools for editing BIND zone files.
During the late 1990s, the sheer quantity of DNS data was overwhelming the tools available to manage it. The cost of managing the data instigated the birth of DNS management software. The costs can best be explained by illustration. In 1998, three of the largest web hosting companies (HostPro, Interland, and Vservers) each hosted about 100,000 DNS zones. DNS changes were made by telnetting to a BIND master and editing zone files with a text editor. A staff of several DNS admins performed this task all day, every day. Their changes would only take effect after a BIND reload. Because disks were slow, it took several hours for BIND to do a full reload. If a DNS admin made a typo in a zone file, BIND would fail to parse that file and die. Often after hours of processing. Whoever noticed BIND wasn't running would have to read the logs, find the zone file with the error, manually review the file, fix the error, and then try starting BIND back up. Once up, the changes |
https://en.wikipedia.org/wiki/Calvatia%20craniiformis | Calvatia craniiformis, commonly known as the brain puffball or the skull-shaped puffball, is a species of puffball fungus in the family Agaricaceae. It is found in Asia, Australia, and North America, where it grows on the ground in open woods. Its name, derived from the same Latin root as cranium, alludes to its resemblance to an animal's brain. The skull-shaped fruit body is broad by tall and white to tan. Initially smooth, the skin (peridium) develops wrinkles and folds as it matures, cracking and flaking with age. The peridium eventually sloughs away, exposing a powdery yellow-brown to greenish-yellow spore mass (the gleba). The puffball is edible when the gleba is still white and firm, before it matures to become yellow-brown and powdery. Mature specimens have been used in the traditional or folk medicines of China, Japan, and the Ojibwe as a hemostatic or wound dressing agent. Several bioactive compounds have been isolated and identified from the brain puffball.
Taxonomy
The species was first described as Bovista craniiformis by Lewis David de Schweinitz in 1832. Elias Fries transferred it to the then newly circumscribed genus Calvatia in 1849, setting Calvatia craniiformis as the type and only species. Scott Bates and colleagues suggest that the name is synonymous with Lycoperdon delicatum published by Miles Joseph Berkeley and Moses Ashley Curtis in 1873 (not the L. delicatum published by Berkeley in 1854), as is Lycoperdon missouriense published by William Trelease in 1891. The form C. craniiformis f. gardneri, published by Yosio Kobayasi in 1932 (originally Lycoperdon gardneri Berk. 1875), since been elevated to the distinct species Calvatia gardneri.
In their 1962 monograph on North American Calvatia, mycologists Sanford Myron Zeller and Alexander H. Smith set C. craniiformis as the type species of the stirps (a grouping of related species) Craniiformis, containing species with a large sterile base and a persistent cottony gleba. Other species they in |
https://en.wikipedia.org/wiki/Cyclin%20D/Cdk4 | The Cyclin D/Cdk4 complex is a multi-protein structure consisting of the proteins Cyclin D and cyclin-dependent kinase 4, or Cdk4, a serine-threonine kinase. This complex is one of many cyclin/cyclin-dependent kinase complexes that are the "hearts of the cell-cycle control system" and govern the cell cycle and its progression. As its name would suggest, the cyclin-dependent kinase is only active and able to phosphorylate its substrates when it is bound by the corresponding cyclin. The Cyclin D/Cdk4 complex is integral for the progression of the cell from the Growth 1 phase to the Synthesis phase of the cell cycle, for the Start or G1/S checkpoint.
Basic Mechanism
Under non-dividing conditions (when the cell is in the G0 phase of the cell cycle), Retinoblastoma protein (Rb) is bound with the E2F transcription factor. Once Cdk4 is activated and is bound with Cyclin D, the Cyclin D/Cdk4 complex phosphorylates Retinoblastoma protein (pRb). Once the Retinoblastoma protein has been phosphorylated, E2F is released. The released E2F is then free to act as a transcription factor and it subsequently binds to DNA promoter regions and activates the expression of proteins required in the next stages of the cell cycle and in DNA replication. Specifically, E2F helps to activate Cyclin E and Cyclin A, which are constituents of other Cdk/Cyclin complexes and are involved in the DNA replication process and other downstream mitotic processes.
Regulation
There are multiple regulation points within this signaling pathway. First and foremost, under non-dividing conditions multiple proteins can inhibit the Cyclin D/Cdk4 complex by binding Cdk4 and inhibiting its association with Cyclin D. Primarily, this is accomplished by p27 but it can also be done by p16 and p21. However, this pathway is stimulated by the upstream binding of growth factors (GF), either from within the cell itself or from neighboring cells. Stimulation by growth factors activates any of a number of receptor tyro |
https://en.wikipedia.org/wiki/Berger%20code | In telecommunication, a Berger code is a unidirectional error detecting code, named after its inventor, J. M. Berger. Berger codes can detect all unidirectional errors. Unidirectional errors are errors that only flip ones into zeroes or only zeroes into ones, such as in asymmetric channels. The check bits of Berger codes are computed by counting all the zeroes in the information word, and expressing that number in natural binary. If the information word consists of bits, then the Berger code needs "check bits", giving a Berger code of length k+n. (In other words, the check bits are enough to check up to information bits).
Berger codes can detect any number of one-to-zero bit-flip errors, as long as no zero-to-one errors occurred in the same code word.
Similarly, Berger codes can detect any number of zero-to-one bit-flip errors, as long as no one-to-zero bit-flip errors occur in the same code word.
Berger codes cannot correct any error.
Like all unidirectional error detecting codes,
Berger codes can also be used in delay-insensitive circuits.
Unidirectional error detection
As stated above, Berger codes detect any number of unidirectional errors. For a given code word, if the only errors that have occurred are that some (or all) bits with value 1 have changed to value 0, then this transformation will be detected by the Berger code implementation. To understand why, consider that there are three such cases:
Some 1s bit in the information part of the code word have changed to 0s.
Some 1s bits in the check (or redundant) portion of the code word have changed to 0s.
Some 1s bits in both the information and check portions have changed to 0s.
For case 1, the number of 0-valued bits in the information section will, by definition of the error, increase. Therefore, our Berger check code will be lower than the actual 0-bit-count for the data, and so the check will fail.
For case 2, the number of 0-valued bits in the information section have stayed the same, but the v |
https://en.wikipedia.org/wiki/Ditto%20mark | The ditto mark is a shorthand sign, used mostly in hand-written text, indicating that the words or figures above it are to be repeated.
The mark is made using "a pair of apostrophes"; "a pair of marks used underneath a word"; the symbol (quotation mark); or the symbol (right double quotation mark).
In the following example, the second line reads "Blue pens, box of twenty".
Black pens, box of twenty ... $2.10
Blue " " " " ... $2.35
History
Early evidence of ditto marks can be seen on a cuneiform tablet of the Neo-Assyrian period (934–608 BCE) where two vertical marks are used in a table of synonyms to repeat text.
In China the corresponding historical mark was two horizontal lines (unicode ), which is also the ancient ideograph of "two", similar to the modern ideograph . It is found in bronze script from the Zhou Dynasty, as in the example at right (circa 825 BCE). In seal script form this became , and is now written as ; see iteration mark.
The word ditto comes from the Tuscan language, where it is the past participle of the verb dire (to say), with the meaning of "said", as in the locution "the said story". The first recorded use of ditto with this meaning in English occurs in 1625. In English, the abbreviation "do." has sometimes been used.
Other languages
For Chinese, Japanese and Korean, there is the specific Unicode character in the range CJK Symbols and Punctuation. This facilitates the setting of both marks on a single horizontal line in Asian vertical text.
Other languages may use equivalent symbols. For example, in German is used. In Swedish and Norwegian handwriting, a version using horizontal lines to indicate the span of the cell in a table where an entry repeats is sometimes seen (––〃––). In French, it is called a , but the actual symbol used may vary. is used in Quebec, while in France is preferred.
See also |
https://en.wikipedia.org/wiki/Implicit%20certificate | In cryptography, implicit certificates are a variant of public key certificate. A subject's public key is reconstructed from the data in an implicit certificate, and is then said to be "implicitly" verified. Tampering with the certificate will result in the reconstructed public key being invalid, in the sense that it is infeasible to find the matching private key value, as would be required to make use of the tampered certificate.
By comparison, traditional public-key certificates include a copy of the subject's public key, and a digital signature made by the issuing certificate authority (CA). The public key must be explicitly validated, by verifying the signature using the CA's public key. For the purposes of this article, such certificates will be called "explicit" certificates.
Elliptic Curve Qu-Vanstone (ECQV) is one kind of implicit certificate scheme. It is described in the document Standards for Efficient Cryptography 4 (SEC4).This article will use ECQV as a concrete example to illustrate implicit certificates.
Comparison of ECQV with explicit certificates
Conventional explicit certificates are made up of three parts: subject identification data, a public key and a digital signature which binds the public key to the user's identification data (ID). These are distinct data elements within the certificate, and contribute to the size of the certificate: for example, a standard X.509 certificate is on the order of 1KB in size (~8000 bits).
An ECQV implicit certificate consists of identification data, and a single cryptographic value. This value, an elliptic curve point, combines the function of public key data and CA signature. ECQV implicit certificates can therefore be considerably smaller than explicit certificates, and so are useful in highly constrained environments such as Radio-frequency Identification RFID tags, where not a lot of memory or bandwidth is available.
ECQV certificates are useful for any ECC scheme where the private and public keys |
https://en.wikipedia.org/wiki/Transversality%20condition | In optimal control theory, a transversality condition is a boundary condition for the terminal values of the costate variables. They are one of the necessary conditions for optimality infinite-horizon optimal control problems without an endpoint constraint on the state variables.
See also
Pontryagin's maximum principle
Further reading
Boundary conditions
Optimal control |
https://en.wikipedia.org/wiki/Lymphokine-activated%20killer%20cell | In cell biology, a lymphokine-activated killer cell (also known as a LAK cell) is a white blood cell that has been stimulated to kill tumor cells. If lymphocytes are cultured in the presence of Interleukin 2, it results in the development of effector cells which are cytotoxic to tumor cells.
Mechanism
It has been shown that lymphocytes, when exposed to Interleukin 2, are capable of lysing fresh, non-cultured cancer cells, both primary and metastatic. LAK cells respond to these lymphokines, particularly IL-2, by lysing tumor cells that were already known to be resistant to NK cell activity.
The mechanism of LAK cells is distinctive from that of natural killer cells because they can lyse cells that NK cells cannot. LAK cells are also capable of acting against cells that do not display the major histocompatibility complex, as has been shown by the ability to cause lysis in non-immunogenic, allogeneic and syngeneic tumors. LAK cells are specific to tumor cells and do not display activity against normal cells.
Cancer Treatment
LAK cells, along with the administration of IL-2 have been experimentally used to treat cancer in mice and humans, but there is very high toxicity with this treatment - Severe fluid retention was the major side effect of therapy, although all side effects resolved after interleukin-2 administration was stopped. LAK cell therapy is a method that uses interleukin 2 (IL-2) to enhance the number of lymphocytes in an in vitro setting, and it has formed the foundation of many immunotherapy assays that are now in use. LAK cells have shown potential as a cellular agent for cancer therapy and have been utilized therapeutically in association with IL-2 for the treatment of various cancers. LAK cells have anticancer efficacy against homologous carcinoma cells and can grow ex vivo in the presence of IL-2. In melanoma and gastric cancer cells, intercellular adhesion molecule 1 (ICAM-1) antibody can significantly inhibit in vitro LAK-induced lysis of cancer c |
https://en.wikipedia.org/wiki/Redux%20%28adhesive%29 | Redux is the generic name of a family of phenol–formaldehyde/polyvinyl–formal adhesives developed by Aero Research Limited (ARL) at Duxford, UK, in the 1940s, subsequently produced by Ciba (ARL). The brand name is now also used for a range of epoxy and bismaleimide adhesives manufactured by Hexcel. The name is a contraction of REsearch at DUXford.
History
Devised at ARL by Dr. Norman de Bruyne and George Newell in 1941 for use in the aircraft industry, the adhesive is used for the bonding of metal-to-metal and metal-to-wood structures. The adhesive system comprises a liquid phenolic resin and a PVF (PolyVinylFormal) thermoplastic powder.
The first formulation available was Redux Liquid E/Formvar, comprising a phenolic liquid (Redux Liquid E) and a PVF powder (Formvar), and after its initial non-aviation related application of bonding clutch plates on Churchill and Cromwell tanks, it was used by de Havilland from 1943 to the early 1960s, on, among other aircraft, the Hornet, the Comet and the derived Nimrod, and the Dove, Heron and Trident. It was also used by Vickers on the Viking and by Chance Vought on the F7U Cutlass.
Typically, Redux would be used to affix stiffening stringers and doublers to wing and fuselage panels, the resulting panel being both stronger and lighter than a riveted structure. In the case of the Hornet it was used to join the aluminium lower-wing skin to the wooden upper wing structure, and in the fabrication of the aluminium/wood main wing spar, both forms of composite construction made possible by the advent of Redux.
After initially supplying de Havilland only, ARL subsequently produced a refined form of Redux Liquid E/Formvar using a new liquid component known as Redux Liquid K6, and a finer-grade (smaller particle-size) PVF powder, and this was later made generally available to the wider aircraft industry as Redux Liquid 775/Powder 775, so-named because it was sold for aircraft use to specification DTD 775*. Available for general non- |
https://en.wikipedia.org/wiki/Stable%20normal%20bundle | In surgery theory, a branch of mathematics, the stable normal bundle of a differentiable manifold is an invariant which encodes the stable normal (dually, tangential) data. There are analogs for generalizations of manifold, notably PL-manifolds and topological manifolds. There is also an analogue in homotopy theory for Poincaré spaces, the Spivak spherical fibration, named after Michael Spivak.
Construction via embeddings
Given an embedding of a manifold in Euclidean space (provided by the theorem of Hassler Whitney), it has a normal bundle. The embedding is not unique, but for high dimension of the Euclidean space it is unique up to isotopy, thus the (class of the) bundle is unique, and called the stable normal bundle.
This construction works for any Poincaré space X: a finite CW-complex admits a stably unique (up to homotopy) embedding in Euclidean space, via general position, and this embedding yields a spherical fibration over X. For more restricted spaces (notably PL-manifolds and topological manifolds), one gets stronger data.
Details
Two embeddings are isotopic if they are homotopic
through embeddings. Given a manifold or other suitable space X, with two embeddings into Euclidean space these will not in general be isotopic, or even maps into the same space ( need not equal ). However, one can embed these into a larger space by letting the last coordinates be 0:
.
This process of adjoining trivial copies of Euclidean space is called stabilization.
One can thus arrange for any two embeddings into Euclidean space to map into the same Euclidean space (taking ), and, further, if is sufficiently large, these embeddings are isotopic, which is a theorem.
Thus there is a unique stable isotopy class of embedding: it is not a particular embedding (as there are many embeddings), nor an isotopy class (as the target space is not fixed: it is just "a sufficiently large Euclidean space"), but rather a stable isotopy class of maps. The normal bundle associated with |
https://en.wikipedia.org/wiki/Polio%20eradication | Polio eradication, the permanent global cessation of circulation of the poliovirus and hence elimination of the poliomyelitis (polio) it causes, is the aim of a multinational public health effort begun in 1988, led by the World Health Organization (WHO), the United Nations Children's Fund (UNICEF) and the Rotary Foundation. These organizations, along with the U.S. Centers for Disease Control and Prevention (CDC) and The Gates Foundation, have spearheaded the campaign through the Global Polio Eradication Initiative (GPEI). Successful eradication of infectious diseases has been achieved twice before, with smallpox in humans and rinderpest in ruminants.
Prevention of disease spread is accomplished by vaccination. There are two kinds of polio vaccine—oral polio vaccine (OPV), which uses weakened poliovirus, and inactivated polio vaccine (IPV), which is injected. OPV is less expensive and easier to administer, and can spread immunity beyond the person vaccinated, creating contact immunity. It has been the predominant vaccine used. However, under conditions of long-term vaccine virus circulation in under-vaccinated populations, mutations can reactivate the virus to produce a polio-inducing strain, while OPV can also, in rare circumstances, induce polio or persistent asymptomatic infection in vaccinated individuals, particularly those who are immunodeficient. Being inactivated, IPV is free of these risks but does not induce contact immunity. IPV is more costly and the logistics of delivery are more challenging.
Nigeria is the latest country to have officially stopped endemic transmission of wild poliovirus, with its last reported case in 2016. Wild poliovirus has been eradicated in all continents except Asia, and , Afghanistan and Pakistan are the only two countries where the disease is still classified as endemic.
Recent polio cases arise from two sources, the original 'wild' poliovirus (WPV), and the much more prevalent mutated oral vaccine strains, known as circulati |
https://en.wikipedia.org/wiki/Reform%20mathematics | Reform mathematics is an approach to mathematics education, particularly in North America. It is based on principles explained in 1989 by the National Council of Teachers of Mathematics (NCTM). The NCTM document Curriculum and Evaluation Standards for School Mathematics (CESSM) set forth a vision for K–12 (ages 5–18) mathematics education in the United States and Canada. The CESSM recommendations were adopted by many local- and federal-level education agencies during the 1990s. In 2000, the NCTM revised its CESSM with the publication of Principles and Standards for School Mathematics (PSSM). Like those in the first publication, the updated recommendations became the basis for many states' mathematics standards, and the method in textbooks developed by many federally-funded projects. The CESSM de-emphasised manual arithmetic in favor of students developing their own conceptual thinking and problem solving. The PSSM presents a more balanced view, but still has the same emphases.
Mathematics instruction in this style has been labeled standards-based mathematics or reform mathematics.
Principles and standards
Mathematics education reform built up momentum in the early 1980s, as educators reacted to the "new math" of the 1960s and 1970s. The work of Piaget and other developmental psychologists had shifted the focus of mathematics educators from mathematics content to how children best learn mathematics. The National Council of Teachers of Mathematics summarized the state of current research with the publication of Curriculum and Evaluation Standards in 1989 and Principles and Standards for School Mathematics in 2000, bringing definition to the reform movement in North America.
Reform mathematics curricula challenge students to make sense of new mathematical ideas through explorations and projects, often in real-world contexts. Reform texts emphasize written and verbal communication, working in cooperative groups, and making connections between concepts and between r |
https://en.wikipedia.org/wiki/Lewisia | Lewisia is a plant genus, named for the American explorer Meriwether Lewis (1774-1809) who encountered the species in 1806. The native habitat of Lewisia species is rocky ground and cliffs in western North America. Local Native Americans ate the roots, which have also been used to treat sore throats.
Characteristics
Lewisias are perennial flowering plants native to western North American habitats including rocky outcrops from the high elevation alpine to lower elevation chaparral, oak woodlands, and coniferous forests. They produce rosette-shaped flowers in a range of different colours. Lewisia cotyledon grow up to in height and width.
About half of the species of Lewisia are deciduous, including the original Lewisia rediviva. Lewisia longipetala is the only semi-deciduous species. Some species, such as Lewisia cotyledon, are evergreen.
Taxonomy
Meriwether Lewis, of Lewis and Clark fame, is credited with the first discovery by a European or American of Lewisia, which was known to the local Native Americans as bitterroot. Lewis discovered the specimen in 1806 at Lolo Creek, in the mountain range that became known as the Bitterroot Mountains. The plant was given its scientific name, Lewisia rediviva, by Frederick Traugott Pursh.
List of species
There are nineteen species and several varieties of Lewisia, including:
Lewisia brachycalyx Engelm. ex A.Gray: United States (California, Arizona, Utah), Mexico (Baja California)
Lewisia cantelovii J.T.Howell: USA (California, Nevada)
Lewisia columbiana (J.T.Howell ex A.Gray) B.L.Rob.
Lewisia columbiana var. columbiana: Canada (British Columbia), USA (Washington, Oregon)
Lewisia columbiana var. rupicola (English) C.L.Hitchc.: Canada (British Columbia), USA (Washington, Oregon)
Lewisia columbiana var. wallowensis C.L.Hitchc.: USA (Idaho, Montana, Oregon)
Lewisia congdonii (Rydb.) S.Clay: USA (California)
Lewisia cotyledon (S.Watson) B.L.Rob.
Lewisia cotyledon var. cotyledon: USA (Oregon, California)
Lewisia c |
https://en.wikipedia.org/wiki/Structure%20theorem%20for%20finitely%20generated%20modules%20over%20a%20principal%20ideal%20domain | In mathematics, in the field of abstract algebra, the structure theorem for finitely generated modules over a principal ideal domain is a generalization of the fundamental theorem of finitely generated abelian groups and roughly states that finitely generated modules over a principal ideal domain (PID) can be uniquely decomposed in much the same way that integers have a prime factorization. The result provides a simple framework to understand various canonical form results for square matrices over fields.
Statement
When a vector space over a field F has a finite generating set, then one may extract from it a basis consisting of a finite number n of vectors, and the space is therefore isomorphic to Fn. The corresponding statement with the F generalized to a principal ideal domain R is no longer true, since a basis for a finitely generated module over R might not exist. However such a module is still isomorphic to a quotient of some module Rn with n finite (to see this it suffices to construct the morphism that sends the elements of the canonical basis of Rn to the generators of the module, and take the quotient by its kernel.) By changing the choice of generating set, one can in fact describe the module as the quotient of some Rn by a particularly simple submodule, and this is the structure theorem.
The structure theorem for finitely generated modules over a principal ideal domain usually appears in the following two forms.
Invariant factor decomposition
For every finitely generated module over a principal ideal domain , there is a unique decreasing sequence of proper ideals such that is isomorphic to the sum of cyclic modules:
The generators of the ideals are unique up to multiplication by a unit, and are called invariant factors of M. Since the ideals should be proper, these factors must not themselves be invertible (this avoids trivial factors in the sum), and the inclusion of the ideals means one has divisibility . The free part is visible in the part o |
https://en.wikipedia.org/wiki/Complete%20set%20of%20invariants | In mathematics, a complete set of invariants for a classification problem is a collection of maps
(where is the collection of objects being classified, up to some equivalence relation , and the are some sets), such that if and only if for all . In words, such that two objects are equivalent if and only if all invariants are equal.
Symbolically, a complete set of invariants is a collection of maps such that
is injective.
As invariants are, by definition, equal on equivalent objects, equality of invariants is a necessary condition for equivalence; a complete set of invariants is a set such that equality of these is also sufficient for equivalence. In the context of a group action, this may be stated as: invariants are functions of coinvariants (equivalence classes, orbits), and a complete set of invariants characterizes the coinvariants (is a set of defining equations for the coinvariants).
Examples
In the classification of two-dimensional closed manifolds, Euler characteristic (or genus) and orientability are a complete set of invariants.
Jordan normal form of a matrix is a complete invariant for matrices up to conjugation, but eigenvalues (with multiplicities) are not.
Realizability of invariants
A complete set of invariants does not immediately yield a classification theorem: not all combinations of invariants may be realized. Symbolically, one must also determine the image of |
https://en.wikipedia.org/wiki/Orientation%20character | In algebraic topology, a branch of mathematics, an orientation character on a group is a group homomorphism where:
This notion is of particular significance in surgery theory.
Motivation
Given a manifold M, one takes (the fundamental group), and then sends an element of to if and only if the class it represents is orientation-reversing.
This map is trivial if and only if M is orientable.
The orientation character is an algebraic structure on the fundamental group of a manifold, which captures which loops are orientation reversing and which are orientation preserving.
Twisted group algebra
The orientation character defines a twisted involution (*-ring structure) on the group ring , by (i.e., , accordingly as is orientation preserving or reversing). This is denoted .
Examples
In real projective spaces, the orientation character evaluates trivially on loops if the dimension is odd, and assigns -1 to noncontractible loops in even dimension.
Properties
The orientation character is either trivial or has kernel an index 2 subgroup, which determines the map completely.
See also
Characteristic class
Local system
Twisted Poincaré duality |
https://en.wikipedia.org/wiki/%CE%93-Tocopherol | γ-Tocopherol (gamma-tocopherol) is a tocopherol and one of the chemical compounds that comprise vitamin E. As a food additive, it has E number E308.
See also
α-Tocopherol
β-Tocopherol
δ-Tocopherol |
https://en.wikipedia.org/wiki/%CE%94-Tocopherol | δ-Tocopherol (delta-tocopherol) is a tocopherol and one of the chemical compounds that is considered vitamin E. As a food additive, it has E number E309.
See also
Alpha-Tocopherol
Beta-Tocopherol
Gamma-Tocopherol |
https://en.wikipedia.org/wiki/Good%20Natured | Good Natured is a book by primatologist Frans de Waal on animal behavior and the evolution of ethics.
Publishing history
The book was published in 1996 by Harvard University Press under the full title Good Natured: The Origins of Right and Wrong in Humans and Other Animals. Much of the book details observations of primate behavior, especially that of chimpanzees and bonobos. On the final page, he concludes:
Notes |
https://en.wikipedia.org/wiki/Paraspeckle | In cell biology, a paraspeckle is an irregularly shaped compartment of the cell, approximately 0.2-1 μm in size, found in the nucleus' interchromatin space. First documented in HeLa cells, where there are generally 10-30 per nucleus, Paraspeckles are now known to also exist in all human primary cells, transformed cell lines and tissue sections. Their name is derived from their distribution in the nucleus; the "para" is short for parallel and the "speckle" refers to the splicing speckles to which they are always in close proximity. Their function is still not fully understood, but they are thought to regulate gene expression by sequestrating proteins or mRNAs with inverted repeats in their 3′ UTRs.
Structure
Paraspeckles are organised into core-shell spheroidal structures; seven proteins on a scaffold of lncRNA NEAT1 (the 23kb isoform termed NEAT1_2 or NEAT1v2). In 2016, West et al. proposed the currently accepted model for Paraspeckles. This was based on their current findings using super-resolution microscopy. Their models state that the NEAT1_2 scaffold folds into a V-shaped unit. Many of these units then are assembled into a core-shell spheroid by FUS proteins. Core proteins SFPQ, NONO and PSPC1 tightly associate to the assembled structure. Finally, the shell forms, composed of partially co-localised TDP43 proteins. Due to the integral nature of NEAT1 to paraspeckles assembly, assembly is thought to occur in close proximity to NEAT1 transcription sites.
It has been noted that Paraspeckles have a great deal of commonality both in features and structures with cytoplasmic stress granules, another type of membrane-less organelle. This conclusion arose from the fact that both contain common component proteins, become more abundant with stress, seem to function through sequestering other proteins and both have distinct core or shell regions with predictable localised molecules.
Localization
Paraspeckles are dynamic structures that are altered in response to cha |
https://en.wikipedia.org/wiki/OCRL | Inositol polyphosphate 5-phosphatase OCRL-1, also known as Lowe oculocerebrorenal syndrome protein, is an enzyme encoded by the OCRL gene located on the X chromosome in humans.
This gene encodes an inositol polyphosphate 5-phosphatase. The responsible gene locus is at Xq26.1. This phosphatase enzyme is in part responsible for regulating membrane trafficking actin polymerization, and is located in several subcellular parts of the trans-Golgi network.
Deficiencies in OCRL-1 may cause with oculocerebrorenal syndrome and also have been linked to Dent's disease. |
https://en.wikipedia.org/wiki/Florey%20Medal | The Florey Medal, also known as the CSL Florey Medal and the Florey Medal for Lifetime Achievement, is an Australian award for biomedical research named in honour of Australian Nobel Laureate Howard Florey. The medal is awarded biennially and the recipient receives $50,000 in prize money.
The Medal was first awarded in 1998, the centenary of Florey's birth. It is administered by the Australian Institute of Policy & Science and has been sponsored by F H Faulding, then Mayne (when they took over Fauldings), Merck Sharp & Dohme, and is currently sponsored by CSL Limited.
Recipients
Past recipients include:
1998 – Barry Marshall and Robin Warren for their work on Helicobacter pylori and its role in gastritis and peptic ulcer disease
2000 – Jacques Miller for work on the function of the thymus
2002 – Colin L. Masters for Alzheimer's disease research
2004 – Peter Colman for structural biology research
2006 – Ian Frazer for development of the cervical cancer vaccine Gardasil
2009 – for research and clinical application in lysosomal disorders
2011 – Graeme Clark for his invention of the bionic ear
2013 – Ruth Bishop for her work on understanding the rotavirus and the creation of a vaccine
2015 – Perry Bartlett for his discoveries that have transformed our understanding of the brain
2017 – Elizabeth Rakoczy from the Lions Eye Institute at the University of Western Australia for her work on a new gene therapy for wet age-related macular degeneration.
2019 – David Vaux and Andreas Strasser of the Walter and Eliza Hall Institute for their work on revealing the links between cell death and cancer.
See also
List of biomedical science awards
List of awards named after people |
https://en.wikipedia.org/wiki/Linux%20Test%20Project | The Linux Test Project (usually referred to as LTP) is a body of regression and conformance tests designed to confirm the behaviour of the Linux kernel as well as glibc.
The LTP is a joint project started by SGI, developed and maintained by IBM, Cisco, Fujitsu, SUSE, Red Hat and others. The project source code was migrated to git and is available on GitHub.
In simple terms, The Linux Test Project is a group aimed at testing and improving Linux. The goal of the LTP is to deliver a suite of automated testing tools for Linux as well as publish the results of tests they run. |
https://en.wikipedia.org/wiki/Unified%20Video%20Decoder | Unified Video Decoder (UVD, previously called Universal Video Decoder) is the name given to AMD's dedicated video decoding ASIC. There are multiple versions implementing a multitude of video codecs, such as H.264 and VC-1.
UVD was introduced with the Radeon HD 2000 Series and is integrated into some of AMD's GPUs and APUs. UVD occupies a considerable amount of the die surface at the time of its introduction and is not to be confused with AMD's Video Coding Engine (VCE).
As of AMD Raven Ridge (released January 2018), UVD and VCE were succeeded by Video Core Next (VCN).
Overview
The UVD is based on an ATI Xilleon video processor, which is incorporated onto the same die as the GPU and is part of the ATI Avivo HD for hardware video decoding, along with the Advanced Video Processor (AVP). UVD, as stated by AMD, handles decoding of H.264/AVC, and VC-1 video codecs entirely in hardware.
The UVD technology is based on the Cadence Tensilica Xtensa processor, which was originally licensed by ATI Technologies Inc. in 2004.
UVD/UVD+
In early versions of UVD, video post-processing is passed to the pixel shaders and OpenCL kernels. MPEG-2 decoding is not performed within UVD, but in the shader processors. The decoder meets the performance and profile requirements of Blu-ray and HD DVD, decoding H.264 bitstreams up to a bitrate of 40 Mbit/s. It has context-adaptive binary arithmetic coding (CABAC) support for H.264/AVC.
Unlike video acceleration blocks in previous generation GPUs, which demanded considerable host-CPU involvement, UVD offloads the entire video-decoder process for VC-1 and H.264 except for video post-processing, which is offloaded to the shaders. MPEG-2 decode is also supported, but the bitstream/entropy decode is not performed for MPEG-2 video in hardware.
Previously, neither ATI Radeon R520 series' ATI Avivo nor NVidia Geforce 7 series' PureVideo assisted front-end bitstream/entropy decompression in VC-1 and H.264 - the host CPU performed this work. UVD han |
https://en.wikipedia.org/wiki/Tiny%20Town%20%28amusement%20park%29 | Tiny Town & Railroad is a miniature village containing over 100 1/6 scale buildings and a gauge miniature railway close to Morrison, Colorado.
History
George Turner, owner of Denver business Turner Moving & Storage and a friend of Buffalo Bill Cody, began building a miniature town for his daughter in 1915. Called Turnerville, he opened the site to the public in 1921.
Turnerville quickly became one of the state's most popular attractions, but it was plagued by damage from adjacent Turkey Creek flooding and a fire burned down the Indian pueblo in 1935. The train was added in 1939 and the name became Tiny Town.
On August 11, 2010 fifteen people were injured as a train entered a curve at the park going between , causing five of the six cars to tip over. An investigation determined the operator was not adequately trained in steam locomotive operation which resulted in confusion of the brake and throttle levers. The state fined Tiny Town $30,500 consisting of $1000 per incident the operator operated the train and $500 for not having documented training of emergency and safety procedures.
See also
Ridable miniature railway |
https://en.wikipedia.org/wiki/LED%20lamp | An LED lamp or LED light is an electric light that produces light using light-emitting diodes (LEDs). LED lamps are significantly more energy-efficient than equivalent incandescent lamps and can be significantly more than most fluorescent lamps. The most efficient commercially available LED lamps have efficiencies exceeding 200 lumens per watt (lm/W) and convert more than half the input power into light. Commercial LED lamps have a lifespan several times longer than both incandescent and fluorescent lamps.
LED lamps require an electronic LED circuit to operate from mains power lines, and losses from this circuit means that the efficiency of the lamp is lower than the efficiency of the LED chips it uses. The driver circuit may require special features to be compatible with lamp dimmers intended for use on incandescent lamps. Generally the current waveform contains some amount of distortion, depending on the luminaires' technology.
The LED lamp market is projected to grow from US$75.8 billion in 2020 and increasing to US$160 billion in 2026.
LEDs come to full brightness immediately with no warm-up delay. Frequent switching on and off does not reduce life expectancy as with fluorescent lighting. Light output decreases gradually over the lifetime of the LED.
Some LED lamps are drop-in replacements for incandescent or fluorescent lamps. LED lamps may use multiple LED packages for improved light dispersal, heat dissipation, and overall cost. The text on retail LED lamp packaging may show the light output in lumens, the power consumption in watts, the color temperature in kelvins or a color description such as "warm white", "cool white" or "daylight", the operating temperature range, whether the lamp is dimmer compatible, whether the lamp is suitable for humid/damp/wet conditions, and sometimes the equivalent wattage of an incandescent lamp delivering the same output in lumens.
History
Before the introduction of LED lamps, three types of lamps were used for the bulk |
https://en.wikipedia.org/wiki/Reverse%20Krebs%20cycle | The reverse Krebs cycle (also known as the reverse tricarboxylic acid cycle, the reverse TCA cycle, or the reverse citric acid cycle, or the reductive tricarboxylic acid cycle, or the reductive TCA cycle)
is a sequence of chemical reactions that are used by some bacteria to produce carbon compounds from carbon dioxide and water by the use of energy-rich reducing agents as electron donors.
The reaction is the citric acid cycle run in reverse. Where the Krebs cycle takes carbohydrates and oxidizes them to CO2 and water, the reverse cycle takes CO2 and H2O to make carbon compounds.
This process is used by some bacteria (such as Aquificota) to synthesize carbon compounds, sometimes using hydrogen, sulfide, or thiosulfate as electron donors. This process can be seen as an alternative to the fixation of inorganic carbon in the reductive pentose phosphate cycle which occurs in a wide variety of microbes and higher organisms.
Differences from Krebs cycle
In contrast to the oxidative citric acid cycle, the reverse or reductive cycle has a few key differences. There are three enzymes specific to the reductive citric acid cycle – citrate lyase, fumarate reductase, and α-ketoglutarate synthase.
The splitting of citric acid to oxaloacetate and acetate is in catalyzed by citrate lyase, rather than the reverse reaction of citrate synthase. Succinate dehydrogenase is replaced by fumarate reductase and α-ketoglutarate synthase replaces α-ketoglutarate dehydrogenase.
The conversion of succinate to 2-oxoglutarate is also different. In the oxidative reaction this step is coupled to the reduction of NADH. However, the oxidation of 2-oxoglutarate to succinate is so energetically favorable, that NADH lacks the reductive power to drive the reverse reaction. In the rTCA cycle, this reaction has to use a reduced low potential ferredoxin.
Relevance to early life
The reaction is a possible candidate for prebiotic early-earth conditions and, therefore, is of interest in the research of th |
https://en.wikipedia.org/wiki/DRAKON | DRAKON () is a free and open source algorithmic visual programming and modeling language developed as part of the defunct Soviet Union Buran space program in 1986 following the need in increase of software development productivity. The visual language provides a uniform way to represent processes in flowcharts.
There are various implementation of the language specification that may be used to draw and export actual flowcharts. Notable examples include free and open source DRAKON Editor (September 2011).
History
The development of DRAKON started in 1986 to address the emerging risk of misunderstandings - and subsequent errors - between users of different programming languages in the Russian space program. Its development was directed by Vladimir Parondzhanov with the participation of the Russian Federal Space Agency (Academician Pilyugin Center, Moscow) and Russian Academy of Sciences (Keldysh Institute of Applied Mathematics).
The language was constructed by formalization, ergonomization and nonclassical structurization of flowcharts described in the ISO 5807-85 standard and Russian standard «Гост 19.701-90».
The goal was to replace specialized languages used in the Buran project with one universal programming language. Namely PROL2 (ПРОЛ2), used for developing inflight systems software for the computer system Biser-4 (Бисер-4), DIPOL (ДИПОЛЬ), used for developing software for the ground maintenance computer systems) and LAKS (ЛАКС), used for modelling.
The work was finished in 1996 (3 years after the Buran project was officially closed), when an automated CASE programming system called "Grafit-Floks" was developed.
This CASE is used since 1996 in: an international project Sea Launch, Russian orbit insertion upper stage Fregat (Russian: Фрегат, frigate) for onboard control systems and tests, upgraded heavy launch vehicle (carrier rocket) Proton-M.
Overview
The name DRAKON is the Russian acronym for "Дружелюбный Русский Алгоритмический [язык], Который Обеспе |
https://en.wikipedia.org/wiki/Simulation%20hypothesis | The simulation hypothesis proposes that what humans experience as the world is actually a simulated reality, such as a computer simulation in which humans themselves are constructs. There has been much debate over this topic, ranging from philosophical discourse to practical applications in computing.
The simulation hypothesis, as formulated by Nick Bostrom, is part of a long tradition of skeptical scenarios. It was presented by Bostrom as not merely a philosophical speculation but an empirical claim with quantifiable probabilities. The hypothesis has received criticism from some physicists, such as Sabine Hossenfelder who has called it pseudoscience and cosmologist George F. R. Ellis, who stated that "[the hypothesis] is totally impracticable from a technical viewpoint" and that "Late-night pub discussion is not a viable theory." Versions of the hypothesis have also been featured in science fiction, appearing as a central plot device in many stories and films, such as The Matrix.
Origins
Human history is full of thinkers who observed the difference between how things seem and how they might actually be, with dreams, illusions and hallucinations providing poetic and philosophical metaphors. For example, the "Butterfly Dream" of Zhuangzi from ancient China, or the Indian philosophy of Maya, or in Ancient Greek philosophy Anaxarchus and Monimus likened existing things to a scene-painting and supposed them to resemble the impressions experienced in sleep or madness.
In the Western philosophical tradition, Plato's Allegory of the Cave stands out as an influential example.
Aztec philosophical texts theorized that the world was a painting or book written by the Teotl.
René Descartes' Evil Demon philosophically formalized these epistemic doubts, to be followed by a large literature with subsequent variations like Brain in a Vat.
Simulation Argument
Nick Bostrom's premise:
Nick Bostrom's conclusion:
Expanded Argument
Bostrom attempted to assess the probability of |
https://en.wikipedia.org/wiki/Pennales | The order Pennales is a traditional subdivision of the heterokont algae known as diatoms. The order is named for the shape of the cell walls (or valves or frustules) of pennate diatoms, which are elongated in valve view. The valves may be linear or oval in shape, and usually bear bilaterally symmetrical ornamental patterns. These patterns are composed of a series of transverse lines (known as striae) that can appear as rows of dots when viewed with an optical microscope. Some pennate diatoms also exhibit a fissure along their longitudinal axis. This is known as a raphe, and is involved in gliding movements made by diatom cells; motile diatoms always possess a raphe.
In terms of cell cycle, vegetative cells are diploid and undergo mitosis during normal cell division. Periodically, meiosis produces morphologically identical haploid gametes (isogametes), which fuse to produce a (sometimes binucleate) zygote that develops into an auxospore (from which full-sized vegetative cells are produced).
In some taxonomic schemes, the pennate diatoms are divided into two groups: pennate diatoms without a raphe (a seam or ridge), known as araphids (order Fragilariophyceae), and pennate diatoms with a raphe, known as raphids (order Bacillariophyceae).
See also
Centrales
Clepsydra |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.