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32,651,361 | https://en.wikipedia.org/wiki/Manganese%28II%29%20iodide | Manganese(II) iodide is the chemical compound composed of manganese and iodide with the formula MnI2(H2O)n. The tetrahydrate is a pink solid while the anhydrous derivative is beige. Both forms feature octahedral Mn centers. Unlike MnCl2(H2O)4 and MnBr2(H2O)4 which are cis, MnI2(H2O)4 is trans.
Preparation
Anhydrous MnI2 is prepared from the elements:
The tetrahydrate can be prepared by treating manganese(II) carbonate with hydriodic acid. The anhydrous form can be produced from it by dehydration in a vacuum.
Properties
Samples turn brown in air under the influence of light as a result of the oxidation of the iodide ion to iodine. It has a trigonal crystal structure of the cadmium iodide type (polytype 2H) with the space group Pm1 (space group no. 164). It dissolves in water and decomposes. The tetrahydrate has a monoclinic crystal structure with the space group P21/c (No. 14).
Applications
It is often used in the lighting industry.
References
Manganese(II) compounds
Iodides
Metal halides | Manganese(II) iodide | Chemistry | 282 |
10,592,978 | https://en.wikipedia.org/wiki/Centralite | Ethyl centralite is an organic compound. Its chemical name is 1,3-diethyl-1,3-diphenylurea. The molecular formula of ethyl centralite is . This compound has important uses in industry and forensics. The structure of ethyl centralite includes two phenyl groups (aromatic rings) attached to a central urea group. There are also ethyl groups (–C₂H₅) bound to the nitrogen atoms of the urea. This structure gives ethyl centralite its special chemical properties. Ethyl centralite is an important part of gunshot residue (GSR). When a gun is fired, the chemical reactions from the burning of the propellant leave behind tiny particles called gunshot residue. Ethyl centralite is one of the compounds found in GSR. It serves as an indicator in forensic investigations. Ethyl centralite helps determine if a firearm was recently fired. Ethyl centralite is widely used in various industries. Its main use is in the production of smokeless powder. In this use, it acts as a burning rate moderator and stabilizer. These functions are important for the controlled and consistent ignition of propellants. This is essential for the safety and effectiveness of ammunition. Ethyl centralite is also used as a plasticizer in the manufacturing of celluloid and enhances the flexibility and durability of the material.
History
In the 19th century chemists identified that nitrocellulose can destroy itself with the help of nitrogen oxides separating from it at storage, and tried to find bases which might capture those oxides. Urea has been used for stabilizing celluloid in the 19th century (and even in early American military powders), but like other water-soluble bases, it also attacks nitrocellulose, so German chemists substituted hydrogen atoms with nonpolar organic radicals to diminish this effect.
Naming
The term "Centralite" was originally applied to dimethyldiphenylurea developed about 1906 at the German private military-industrial laboratory (Center for Scientific-Technical Research) in Neubabelsberg as a deterrent coating for smokeless powder in military rifle cartridges. Thereafter, all hydrocarbon-substituted symmetrical diphenyl urea compounds used as smokeless powder deterrents (or moderants) were called centralites after the laboratory. The preferred ethyl centralite became known as Centralite No. 1 and the original methyl centralite was identified as Centralite No. 2. Butyl centralite was also used as a celluloid plasticizer.
Comparison with analogs
Compared to diphenylurea, it has a far more convoluted reaction history. Finally, nitrated anilines are produced. Centralite-2, also known as sym-dimethyldiphenylurea, is a methyl analog that is moderately utilized overseas. Though they are likewise excellent plasticizers, centralites are thought to be a little less effective stabilizer than 2-nitrodiphenylamine. To benefit from their plasticizing qualities, they are commonly employed in propellants at higher fractions than diphenylamines.
Synthesis
Ethyl centralite is also known as 1,3-diethyl-1,3-diphenylurea. It is synthesized through a chemical reaction. This reaction involves the condensation of aniline (C₆H₅NH₂) with ethyl isocyanate (C₂H₅NCO). The reaction typically occurs under controlled conditions. In this reaction, aniline reacts with ethyl isocyanate. This forms ethyl centralite through the formation of urea linkages.
The general reaction can be represented as follows:
In this reaction, aniline () serves as the aromatic amine and ethyl isocyanate () is the isocyanate compound that reacts with the amine groups.
The reaction produces ethyl centralite. It also produces carbon dioxide (CO₂) as a byproduct. The process is usually done in a solvent, such as an alcohol. The solvent helps dissolve the reactants. It also helps control the reaction temperature. After the reaction is finished, the ethyl centralite is purified. This is done through recrystallization or other purification methods. The goal is to obtain a pure product.
Applications
Smokeless powder
Burning rate moderator: Smokeless powder is a type of propellant used in firearms and ammunition. It burns in a more controlled and steady way. It produces less smoke and residue than traditional black powder. The burning rate of this powder is crucial for a firearm to work properly. If it burns too fast, it can create too much pressure. This can damage the weapon and cause injury. If it burns too slow, it may not generate enough pressure to shoot the bullet effectively. Ethyl centralite helps regulate the burning rate of smokeless powder. It controls the chemical reactions that happen during the ignition of the powder. The presence of ethyl centralite in the powder formulation ensures a steady and predictable energy release during combustion. This controlled burn is important for maintaining the balance between pressure and velocity. This balance enhances the accuracy, safety, and performance of firearms. By moderating the burn rate, ethyl centralite contributes to the reliability of the ammunition. It is a vital component in the manufacturing of smokeless powder.
Stabilizer: It also acts as a stabilizer in smokeless powder. The chemical compounds in smokeless powder can decompose over time. This is especially true when exposed to heat, moisture, and age. The decomposition can create acidic byproducts. These byproducts can speed up the breakdown of the powder. This can compromise the powder's stability. Ethyl centralite acts as a stabilizer. It inhibits the degradation processes. It neutralizes the acidic byproducts that form over time. This slows down the overall decomposition of the powder. This stabilization is important. It extends the shelf life of the smokeless powder. This ensures that the powder remains effective and safe to use even after long periods of storage. Smokeless powder can become unstable without ethyl centralite. This can lead to inconsistent performance. In extreme cases, it can even lead to spontaneous ignition or explosion. Ethyl centralite prevents the powder from degrading prematurely. This helps maintain the integrity and safety of ammunition. Ethyl centralite is an indispensable additive in the production of smokeless powder.
Forensic science
Gunshot Residue (GSR) Analysis: Ethyl centralite is important in forensic science. It is used to analyze gunshot residue (GSR). GSR is tiny particles that come out of a gun when it is fired. These particles can be found on the hands, clothes, or around the person who fired the gun. Analyzing GSR can give important evidence in criminal cases. It can help determine if a suspect recently fired a gun.
Detection of Ethyl Centralite in GSR: Ethyl centralite is an important organic compound found in GSR analysis. When a gun is fired, the smokeless powder used as fuel burns. This creates a mixture of gases and particles. Ethyl centralite is a part of this smokeless powder. It is released along with other residues. Forensic scientists use advanced techniques like gas chromatography-mass spectrometry (GC-MS) to detect ethyl centralite in the residue collected from a suspect or crime scene.Some other compounds may be present in the environment, but ethyl centralite is strongly linked to the firing of a gun. Its presence in GSR can be strong evidence connecting a suspect to the use of a firearm.
References
External links
Fine Chemicals & Intermediates : Ethyl Centralite
Ureas
Plasticizers
Forensic science
Polymers
Firearm actions
Organic chemistry | Centralite | Chemistry,Materials_science | 1,603 |
76,702,542 | https://en.wikipedia.org/wiki/NGC%205279 | NGC 5279 is a spiral galaxy in the constellation Ursa Major. It was discovered by German-British astronomer William Herschel in 1789. NGC 5279 is in gravitational interaction with the galaxy NGC 5278. This pair of galaxies appears in Halton Arp's Atlas of Peculiar Galaxies under the designation Arp 239. The luminosity class of NGC 5279 is I1. NGC 5279 is a galaxy whose core shines in the ultraviolet region. It is listed in the Markarian catalog under the designation Mrk 271 (MK 271).
NGC 5278 Group
According to Abraham Mahtessian, NGC 5278 and UGC 8671 form a pair of galaxies. Mahtessian further mentions that NGC 5278 and NGC 5279 form a pair of galaxies. In reality, these galaxies therefore form a trio of galaxies, the group of NGC 5278. The other galaxy in the same region of the celestial sphere is PGC 48439. With a radial speed of 11,939 km/s, this galaxy is almost two times further away than the members of this trio.
See also
List of NGC objects (5001–6000)
Lists of galaxies
Astrophysics
References
External links
NGC 5279 at NASA/IPAC
NGC 5279 at SIMBAD
Ursa Major
5279
239
Spiral galaxies
Peculiar galaxies
Astronomical objects discovered in 1789
Discoveries by William Herschel
Interacting galaxies | NGC 5279 | Astronomy | 295 |
22,131,467 | https://en.wikipedia.org/wiki/NSA%20Hall%20of%20Honor | The Hall of Honor is a memorial at the National Security Agency headquarters in Fort Meade, Maryland. It honors individuals who rendered distinguished service to American cryptology.
The Hall of Honor
The Hall of Honor is located on the grounds of the National Cryptologic Museum adjacent to NSA's headquarters in Ft. Meade, MD. Created in 1999, The standards are high for induction into the Hall of Honor. The individuals honored were innovators over their entire peers or made major contributions to the structure and processes of American cryptology.
Inductees
Yearly, the National Cryptologic Museum Foundation recommends a slate of honorees to the National Security Agency for consideration along with nominees from other sources.
2023
Evelyn Akeley
James Lovell
Major General Joseph Mauborgne
James Radford
Harry Rashbaum
2022
Eunice Russel Willson Rice
Youn P. (YP) Kim
Richard "Dickie" George
Robert Orestes Ferner
2021
Joseph E. Gilligan, Jr.
Jack C. Mortick
Clifford Cocks, James H. Ellis, and Malcolm J. Williamson
2020
George Cotter
Whitfield Diffie
David Kahn (writer)
Barbara McNamara
Lester Myers
2019
Edward M. Drake
Chief Radioman Harry Kidder, USN
Colonel Alva Bryan Lasswell, USMC
Lieutenant General Kenneth A. Minihan, USAF
2018
Richard L. "Dick" Bernard
Seymour R. Cray
Michael J. Jacobs
Hilda Faust Mathieu
Whitney E. Reed
2017
Mary H. "Polly" Budenbach
Dennis M. Chiari
Colonel Frank E. Herrelko, USAF
Admiral Bobby Inman, USN
Floyd L. Weakley
2016
Gerald Hale
Captain Leonard T. Jones, USCG
Command Sergeant Major Odell Williams, USA
2015
Ralph W. Adams, Jr.
Charles R. Lord
William O. Marks
Robert J. McNelis
Virginia Jenkins Riley
2014
Frank C. Austin
Walter Deeley
Howard Ehret
Marian Rejewski
Alan Turing
2013
Vera Ruth Filby
Richard Proto
Washington Wong
Native American Code talkers
2012
Ann Caracristi
Robert E. Drake
Ronald Hunt
Juliana Mickwitz
2011
William D. Coffee
Joseph Desch
Colonel Parker Hitt
Laura Holmes
2010
Joseph Amato
David Boak
Genevieve Grotjan Feinstein
Leo Rosen
2009
Richard A. Day Jr.
Minnie M. Kenny
Major general Doyle E. Larson
Arthur Levenson
2008
Benson K. Buffman
Charles L. Gandy
General Alfred M. Gray
Oliver R. Kirby
Rear Admiral Donald M. Showers
2007
Jacob "Jack" Gurin
Robert J. Hermann
Samuel Simon Snyder
Milton Zaslow
2006
Brigadier General Bernard Ardisana
Edward A. Everett
Cecil J. Phillips
James W. Pryde
Thomas E. Tremain
2005
William Blankinship
Francis Raven
Arthur J. Salemme
Rear Admiral Joseph N. Wenger
2004
Dorothy T. Blum
James R. Chiles
Meredith Gardner
Brigadier General John Tiltman
2003
Lambros D. Callimahos
Lowell K. Frazer
Juanita Moody
Howard E. Rosenblum
2002
Captain Thomas H. Dyer
Norman Wild
Richard A. Leibler
Mitford M. Mathews
Charles C. Tevis
Julia Ward
2001
Howard C. Barlow
Mahlon E. Doyle
Sydney Jaffe
Major General John E. Morrison
2000
Louis W. Tordella
Captain Joseph Rochefort
Agnes Meyer Driscoll
1999
William F. Friedman
Elizebeth Friedman
Herbert Yardley
Captain Laurance Safford
Frank Rowlett
Abraham Sinkov
Solomon Kullback
Lieutenant General Ralph Canine
References
See also
National Security Agency/Central Security Service Cryptologic Memorial
CIA Memorial Wall
Military Intelligence Hall of Fame
National Security Agency
National Cryptologic Museum
National Security Agency
Monuments and memorials in Maryland
Science and technology halls of fame
Halls of fame in Maryland
Awards established in 1999 | NSA Hall of Honor | Technology | 743 |
78,406,458 | https://en.wikipedia.org/wiki/Difenoxuron | Difenoxuron (commercially known as Lironion) is a phenylurea herbicide used to control annual broad-leaved weeds and grasses in allium crops (predominantly onions), carrots, jojoba, and celery.
Production
Difenoxuron may be synthesized from 4-chloroaniline, 4-methoxyphenol, dimethylamine, and phosgene. It is stereochemically achiral.
Mechanism of action
Difenoxuron is a member of the phenylurea class of herbicides. Phenylureas inhibit photosynthesis at photosystem II by binding to the serine 264 residue of the D1 protein, occupying the Qb (secondary plastoquinone) binding site and hence halting electron transfer from the primary acceptor Qa to the secondary acceptor Qb. This prevents fixation and energy production.
Moreover, this blockade prevents chlorophyll from transferring energy to Qa, increasing production of triplet-state chlorophyll, which reacts with molecular oxygen to form singlet oxygen, a highly reactive species that oxidatively damages the pigments, lipids and proteins of the photosynthetic thylakoid membrane.
Herbicidal activity
Liming in Boddington soil has been shown by a 1976 study to increase the herbicidal toxicity of difenoxuron by two to three times compared to soil without the additional level of liming.
Toxicology
Difenoxuron's hazards include acute toxicity caused by oral ingestion, and acute toxicity of inhalation. There are very few studies about the genotoxicity of difenoxuron and these studies are inconcordant but there appears to be a dose dependent relationship between the concentration of difenoxuron and rate of observed chromosomal aberrations.
References
Herbicides
Ureas
Diphenyl ethers | Difenoxuron | Chemistry,Biology | 397 |
9,914,431 | https://en.wikipedia.org/wiki/Video%20games%20and%20Linux | Linux-based operating systems can be used for playing video games. Because few games natively support the Linux kernel, various software has been made to run Windows games, software, and programs, such as Wine, Cedega, DXVK, and Proton, and managers such as Lutris and PlayOnLinux. The Linux gaming community has a presence on the internet with users who attempt to run games that are not officially supported on Linux.
History
Linux gaming started largely as an extension of the already present Unix gaming scene, which dates back to that system's conception in 1969 with the game Space Travel and the first edition in 1971, with both systems sharing many similar titles. These games were mostly either arcade and parlour type games or text adventures using libraries like curses. A notable example of this are the "BSD Games", a collection of interactive fiction and other text-mode amusements. The free software philosophy and open-source methodology which drove the development of the operating system in general also spawned the creation of various early free games.
Popular early titles included Netrek and the various XAsteroids, XBattle, XBill, XBoing, X-Bomber, XConq, XDigger, XEmeraldia, XEvil, XGalaga, XGammon, XLander, XLife, XMahjong, XMine, XSoldier, XPilot, XRobots, XRubiks, XShogi, XScavenger, XTris, XTron, XTic and XTux games using the X Window System. Other games targeted or also supported the SVGAlib library allowing them to run without a windowing system, such as LinCity, Maelstrom, Sasteroids, and SABRE. The General Graphics Interface was also utilized for games like U.R.B.A.N The Cyborg Project and Dave Gnukem ported from MS-DOS. As the operating system itself grew and expanded, the amount of free and open-source games also increased in scale and complexity, with both clones of historically popular releases beginning with BZFlag, LinCity, and FreeCiv, as well as original creations such as Rocks'n'Diamonds, Cube, The Battle for Wesnoth, and Tux Racer.
1994
The beginning of Linux as a gaming platform for commercial video games is widely credited to have begun in 1994 when Dave D. Taylor ported the game Doom to Linux, as well as many other systems, during his spare time. Shareware copies of the game were included on various Linux discs, including those packed in with reference books.
Ancient Domains of Mystery was also released for Linux in 1994 by Thomas Biskup, building on the roguelike legacy of games such as Moria and its descendent Angband, but more specifically Hack and NetHack.
1995
From there Taylor would also help found the development studio Crack dot Com, which released the video game Abuse, with the game's Linux port even being distributed by Linux vendors Red Hat and Caldera. The studio's never finished Golgotha was also slated to be released by Red Hat in box.
In 1991 DUX Software contracted Don Hopkins to port SimCity to Unix, which he ported to Linux in 1995 and eventually released as open source for the OLPC XO Laptop.
A website called The Linux Game Tome, also known as HappyPenguin after its URL, was begun by Tessa Lau in 1995 to catalogue games created for or ported to Linux from the SunSITE game directories as well as other classic X11 games for a collection of just over 100 titles.
1996–1997
id Software, the original developers of Doom, also continued to release their products for Linux. Their game Quake was ported to Linux via X11 in 1996, once again by Dave D. Taylor working in his free time. An SVGALib version was also later produced by Greg Alexander in 1997 using recently leaked source code, but was later mainlined by id. Later id products continued to be ported by Zoid Kirsch and Timothee Besset, a practice that continued until the studio's acquisition by ZeniMax Media in 2009. Initially, Zoid Kirsch was responsible for maintaining the Linux version of Quake and porting QuakeWorld to Linux.
Inner Worlds was released for and developed on Linux. The UNIX Book of Games, a 1996 publication by Janice Winsor, described various games with an accompanying CD-ROM containing executables and source code for Linux and SCO Unix.
1998
The Linux Game Tome was taken over by Bob Zimbinski in 1998 eventually growing to over 2000 entries, sponsored by retailer Penguin Computing and later LGP until it went down in 2013, although mirrors still exist.
The site LinuxGames covered news and commentary from November 1998 until its host Atomicgamer went down in 2015. It was established by Marvin Malkowski, head of the Telefragged gaming network, alongside Al Koskelin and Dustin Reyes; Reyes passed away August 8, 2023.
Zoid Kirsch from id Software ported Quake II to Linux. Two programmers from Origin ported Ultima Online to Linux and MP Entertainment released an adventure game Hopkins FBI for Linux
On November 9, 1998, a new software firm called Loki Software was founded by Scott Draeker, a former lawyer who became interested in porting games to Linux after being introduced to the system through his work as a software licensing attorney. Loki, although a commercial failure, is credited with the birth of the modern Linux game industry. Loki developed several free software tools, such as the Loki installer (also known as Loki Setup), and supported the development of the Simple DirectMedia Layer, as well as starting the OpenAL audio library project. These are still often credited as being the cornerstones of Linux game development. They were also responsible for bringing nineteen high-profile games to the platform before its closure in 2002.
1999
Loki published Civilization: Call to Power, Eric's Ultimate Solitaire, Heretic II, Heroes of Might and Magic III, Railroad Tycoon II: Gold Edition, Quake III: Arena, and Unreal Tournament for Linux.
Loki's initial success also attracted other firms to invest in the Linux gaming market, such as Tribsoft, Hyperion Entertainment, Macmillan Digital Publishing USA, Titan Computer, Xatrix Entertainment, Philos Laboratories, and Vicarious Visions.
The ports of Quake and Quake II were released physically by Macmillan Computer Publishing USA, while Quake III was released for Linux by Loki Software. Red Hat had previously passed on publishing Quake for Linux, since it was not open-source at the time.
Philos Laboratories released a Linux version of Theocracy on the retail disk. Ryan "Ridah" Feltrin from Xatrix Entertainment released a Linux version of Kingpin: Life of Crime.
BlackHoleSun Software released Krilo and Futureware 2001 released a trading simulation Würstelstand for Linux.
The Indrema Entertainment System (also known as the L600) was also in development since 1999 as a Linux based game console and digital media player, but production halted in 2001 due to a lack of investment, although the TuxBox project attempted a continuation.
2000
Loki published Descent 3, Heavy Gear II, SimCity 3000, and Soldier of Fortune for Linux. They also released the expansion Descent 3: Mercenary as the downloadable Linux installer.
Hyperion Entertainment ported Sin to Linux published by Titan Computer. Vicarious Visions ported the space-flight game Terminus to Linux. Mountain King Studios released a port of Raptor: Call of the Shadows and CipSoft published the Linux client of Tibia.
Boutell.com ported Exile III: Ruined World to Linux, which was a game created by Spiderweb Software.
During this time Michael Simms founded Tux Games, one of the first online Linux game retailers, later followed by Fun 4 Tux, Wupra, ixsoft, and LinuxPusher.
The period also saw a number of commercial compilations released, such as 100 Great Linux Games by Global Star Software, Linux Games by Walnut Creek CDROM, Linux Games++ by Pacific Hitech, Linux Cubed Series 8 LINUX Games by Omeron Systems, Best Linux Games by SOT Finnish Software Engineering, LinuxCenter Games Collection, Linux Games & Entertainment for X Windows by Hemming, Linux Spiele & Games by more software, Linux Spiele by Franzis Verlag, and play it! Linux: Die Spielesammlung by S.A.D. Software. Numerous Linux distributions and collections packed in Loki games and demos, including Red Hat Linux, Corel Linux and WordPerfect Office, and the complete Eric's Ultimate Solitaire bundled with PowerPlant by TheKompany.
2001
Loki published Heavy Metal: F.A.K.K.², Kohan: Immortal Sovereigns, MindRover: The Europa Project, Myth II: Soulblighter, Postal Plus, Rune, Rune: Halls of Valhalla, Sid Meier's Alpha Centauri, and Tribes 2 for Linux.
Linux Game Publishing was founded in 2001 in response to the impending demise of Loki. Creature Labs ported Creatures: Internet Edition to Linux, which was published by LGP.
Hyperion Entertainment ported Shogo: Mobile Armor Division to Linux, and Tribsoft created a Linux version of Jagged Alliance 2, both published by Titan Computer.
Illwinter Game Design released Conquest of Elysium II and Dominions: Priests, Prophets & Pretenders for Linux. Introversion Software released Uplink for Linux.
BlackHoleSun Software released Bunnies, and worked on Atlantis: The Underwater City - Interactive Storybook published by Sterling Entertainment.
GLAMUS GmbH released a Linux version of their game Mobility and Oliver Hamann released the driving game Odyssey by Car.
Small Rockets published Small Rockets BackGammon, Small Rockets Mah Jongg, and Small Rockets Poker for Linux.
The company TransGaming marketed as a monthly subscription its own proprietary fork of Wine called WineX in October 2001, later renamed Cedega in 2004 and discontinued in 2011, which aimed for greater compatibility with Microsoft Windows games.
A special Gaming Edition of Mandrake Linux 8.1 was released that featured WineX packed in with The Sims. The fact that the fork of Wine did not release source back to the main project was also a point of contention, despite promises to release code after achieving a set number of subscribers.
The release of ScummVM in 2001, Dosbox in 2002, as well as video game console emulators like MAME from 1997 and released as open source in 2016, helped make Linux a viable platform for retro gaming (facilitated by the RetroArch frontend since 2010). This is especially the case for the GP2X series of handheld game consoles by GamePark Holdings in addition to the community driven Pandora and DragonBox Pyra. Dedicated emulation setups are also built on single-board computers like the Raspberry Pi released in 2012, which are most often Linux based including with Raspberry Pi OS. Wine is also useful for running older Windows games, including 16-bit and even some 32-bit applications that no longer work on modern 64-bit Windows. The Sharp Zaurus personal data assistants adopted a Linux derived system called OpenZaurus, which attracted its own gaming scene. This was also the case with the Agenda VR3, advertised as the first "pure Linux PDA".
2002
After Loki's closure, the Linux game market experienced some changes. Although some new firms, such as Linux Game Publishing and RuneSoft, would largely continue the role of a standard porting house, the focus began to change with Linux game proponents encouraging game developers to port their game products themselves or through individual contractors. Influential to this was Ryan C. Gordon, a former Loki employee who would over the next decade port several game titles to multiple platforms, including Linux.
Ryan ported America's Army, Candy Cruncher, Serious Sam: The First Encounter, and Unreal Tournament 2003 to Linux.
Linux Game Publishing had initially tried to pick up the support rights to many of Loki's titles, but in the end it was only able to acquire the rights to MindRover: The Europa Project. They released the updated version of Mindrover and its downloadable update for owners of the old Loki version.
Return to Castle Wolfenstein was released for Linux and with the Linux port done in-house by Timothee Besset
Chronic logic released Bridge Construction Set and Triptych for Linux.
Sunspire Studios released in retail commercial expansion of the game titled Tux Racer.
2003
Ryan ported Devastation, Medal of Honor Allied Assault, and Serious Sam: The Second Encounter to
Linux.
LGP took interest in publishing Pyrogon games on physical CDs and they released Candy Cruncher. Mathieu Pinard from Tribsoft got LGP in contact with Cyberlore to save the Linux port of Majesty because Titan Computer get out of Linux publishing. This turn of events helped LGP to release a Majesty for Linux after Pinard closed his company in 2002.
Timothee Bessett from id Software ported Wolfenstein: Enemy Territory to Linux.
Around this time many companies, starting with id Software, also began to release legacy source code leading to a proliferation of source ports of older games to Linux and other systems. This also helped expand the already existing free and open-source gaming scene, especially with regards to the creation of free first person shooters. In addition, numerous game engine recreations have been produced to varying levels of accuracy using reverse engineering or underlying engine code supporting the original game files including on Linux and other niche systems.
2004
Ryan ported Unreal Tournament 2004 to Linux for Epic Games and Timothee Bessett from id Software ported Doom 3 to Linux.
David Hedbor, founder and main programmer of Eon Games ported NingPo MahJong and Hyperspace Delivery Boy! to Linux, which later were published by LGP.
2005–2007
Ryan ported Postal²: Share The Pain to Linux published by LGP.
CodeWeavers offered an enhanced version of Wine called CrossOver Games. The reliance on such compatibility layers remains controversial with concerns that it hinders growth in native development, although this approach was defended based on Loki's demise. PlayOnLinux, established in 2007, provides a community alternative, with various guides being written on how to get games to run through Wine.
2008–2011
The Linux gaming market also started to experience some growth towards the end of the decade with the rise of independent video game development, with many "indie" developers favouring support for multiple platforms. The Humble Indie Bundle initiatives inaugurated in 2010 helped to formally demonstrate this trend, with Linux users representing a sizable population of their purchase base, as well as consistently being the most financially generous in terms of actual money spent. The Humble Indie Bundle V in 2012 faced controversy for featuring a Wine-based release of Limbo prepared by CodeWeavers, while a native version was later released in 2014. Humble eventually began offering Windows-only games in their bundles and on their store.
In 2009, the small indie game company Entourev LLC published Voltley to Linux which is the first commercial exclusive game for this operating system. In the same year, LGP released Shadowgrounds which was the first commercial game for Linux using the Nvidia PhysX middleware. The GamingOnLinux website was launched on July 4, 2009, and eventually succeeded LinuxGames as the main source of news and commentary.
The release of a Linux version of Desura in 2011, a digital distribution platform with a primary focus on small independent developers, was heralded by several commentators as an important step to greater acknowledgement of Linux as a gaming platform. Shortly before this, Canonical launched the Ubuntu Software Center which also sold digital games. The digital store Gameolith also launched in 2011 focused principally on Linux before expanding in 2012 and closing in 2014.
2012–2016
In July 2012, game developer and content distributor Valve announced a port of their Source engine for Linux as well as stating their intention to release their Steam digital distribution service for Linux. The potential availability of a Linux Steam client had already attracted other developers to consider porting their titles to Linux, including previously Mac OS only porting houses such as Aspyr Media and Feral Interactive.
In November 2012, Unity Technologies ported their Unity engine and game creation system to Linux starting with version 4. All of the games created with the Unity engine can now be ported to Linux easily.
In September 2013 Valve announced that they were releasing a gaming oriented Linux based operating system called SteamOS with Valve saying they had "come to the conclusion that the environment best suited to delivering value to customers is an operating system built around Steam itself." This was used for their Steam Machine platform released on November 10, 2015, and discontinued in 2018.
In March 2014 GOG.com announced they would begin to support Linux titles on their DRM free store starting the same year, after previously stating they would not be able due to too many distributions. GOG.com began their initial roll out on July 24, 2014, by offering 50 Linux supporting titles, including several new to the platform.
Despite previous statements, GOG have confirmed they have no plans to port their Galaxy client to Linux. The free software Lutris started in 2010, GameHub from 2019, MiniGalaxy from 2020, and the Heroic Games Launcher from 2021, offer support for GOG as well as the Epic Games Store, Ubisoft Connect and Origin.
In March and April 2014 two major developers Epic Games and Crytek announced Linux support for their next generation engines Unreal Engine 4 and CryEngine respectively.
Towards the end of 2014 the game host itch.io announced that Linux would be supported with their developing open source game client. This was fully launched simultaneously on Windows, Mac OS X and Linux on December 15, 2015. The service had supported Linux since it was first unveiled on March 3, 2013, with creator Leaf Corcoran personally a Linux user. The similar Game Jolt service also supports Linux and has an open source client released on January 13, 2016. GamersGate also sells games for Linux.
2017-present
On August 22, 2018, Valve released their fork of Wine called Proton, aimed at gaming. It features some improvements over the vanilla Wine such as Vulkan-based DirectX 11 implementation, Steam integration, better full screen and game controller support and improved performance for multi-threaded games. It has since grown to include support for DirectX 9 and DirectX 12 over Vulkan. The itch.io app added its own Wine integration in June 2020, while Lutris and PlayOnLinux are long-standing independent solutions for compatibility wrappers.
As with Wine and Cedega in the past, concerns have been raised over whether Proton hinders native development more than it encourages use of the platform. Prodeus dropped native support in favour of Proton shortly before final release and Arcen Games cancelled planned native support for Heart of the Machine. Valve has expressed no preference over Proton or native ports among developers.
On February 25, 2022, Valve released Steam Deck, a handheld game console running SteamOS 3.0. The deployment of Proton and other design decisions were based on the limited response to their previous Steam Machines. Linux was also used as a base for several nostalgia consoles, including the Neo Geo X, NES Classic Edition, Super NES Classic Edition, Sega Genesis Mini, Intellivision Amico, Lichee Pocket 4A, and the Atari VCS. It also powers the more general Polymega, Anbernic RG351 and 5G552, as well as the Game Gadget, Evercade, VS, EXP and Super Pocket retrogaming consoles by Blaze Entertainment.
As of early 2023, the retro game store Zoom Platform was enhancing Linux support on their available titles.
Commercial games for non-x86 instruction sets
Some companies ported games to Linux running on instruction sets other than x86, such as Alpha, PowerPC, Sparc, MIPS or ARM.
Loki Entertainment Software ported Civilization: Call to Power, Eric's Ultimate Solitaire, Heroes of Might and Magic III, Myth II: Soulblighter, Railroad Tycoon II Gold Edition and Sid Meier's Alpha Centauri with Alien Crossfire expansion pack to Linux PowerPC. They also ported Civilization: Call to Power, Eric's Ultimate Solitaire, Sid Meier's Alpha Centauri with Alien Crossfire expansion pack to Linux Alpha and Civilization: Call to Power, Eric's Ultimate Solitaire to Linux SPARC.
Linux Game Publishing published Candy Cruncher, Majesty Gold, NingPo MahJong and Soul Ride to Linux PowerPC. They also ported Candy Cruncher, Soul Ride to Linux SPARC and Soul Ride to Linux Alpha.
Illwinter Game Design ported Dominions: Priests, Prophets and Pretenders, Dominions II: The Ascension Wars and Dominions 3 to Linux PowerPC, as well as Conquest of Elysium 3, Dominions 4: Thrones of Ascension to Raspberry Pi.
Hyperion Entertainment ported Sin to Linux PowerPC published by Titan Computer and Gorky 17 to Linux PowerPC which later was published by LGP.
Runesoft hired Gunnar von Boehn which ported Robin Hood – The Legend of Sherwood to Linux PowerPC. Later Runesoft ported Airline Tycoon Deluxe to Raspberry Pi was running Debian GNU/Linux.
Iain McLeod ported Spheres of Chaos to Linux on the PlayStation 2 consoles and later re-released it as a freeware game.
Market share
The Steam Hardware Survey reports that as of January 2024, 2% of users are using some form of Linux as their platform's primary operating system. The Unity game engine used to make their statistics available and in March 2016 reported that Linux users accounted for 0.4% of players. In 2010, in the first Humble Bundle sales, Linux accounted for 18% of purchases.
Supported hardware
Linux as a gaming platform can also refer to operating systems based on the Linux kernel and specifically designed for the sole purpose of gaming. Examples are SteamOS, which is an operating system for Steam Machines, Steam Deck and general computers, video game consoles built from components found in the classical home computer, (embedded) operating systems like Tizen and Pandora, and handheld game consoles like GP2X, and Neo Geo X. The Nvidia Shield runs Android as an operating system, which is based on a modified Linux kernel.
The open source design of the Linux software platform allows the operating system to be compatible with various computer instruction sets and many peripherals, such as game controllers and head-mounted displays. As an example, HTC Vive, which is a virtual reality head-mounted display, supports the Linux gaming platform.
Performance
In 2013, tests by Phoronix showed real-world performance of games on Linux with proprietary Nvidia and AMD drivers were mostly comparable to results on Windows 8.1. Phoronix found similar results in 2015, though Ars Technica described a 20% performance drop with Linux drivers.
Software architecture
An operating system based on the Linux kernel and customized specifically for gaming, could adopt the vanilla Linux kernel with only little changes, or—like the Android operating system—be based on a relative extensively modified Linux kernel. It could adopt GNU C Library or Bionic or something like it. The entire middleware or parts of it, could very well be closed-source and proprietary software; the same is true for the video games. There are free and open-source video games available for the Linux operating system, as well as proprietary ones.
Linux kernel
The subsystems already mainlined and available in the Linux kernel are most probably performant enough so to not impede the gaming experience in any way, however additional software is available, such as e.g. the Brain Fuck Scheduler (a process scheduler) or the Budget Fair Queueing (BFQ) scheduler (an I/O scheduler).
Similar to the way the Linux kernel can be, for example, adapted to run better on supercomputers, there are adaptations targeted at improving the performance of games. A project concerning itself with this issue is called Liquorix.
Available software for video game designers
Game creation systems
Several game creation systems can be run on Linux, such as Game Editor, GDevelop, Construct and Stencyl, as well as beta versions of GameMaker. A Linux version of Clickteam Fusion 3 was mentioned, but has yet to be released. The Godot, Defold, and Solar2D game engines also supports creating games on Linux, as do the commercial UnrealEd and Unity Editor, The visual programming environments Snap!, Scratch 1.X and Tynker are Linux compatible. Enterbrain's RPG Maker MV was released for Linux. In addition, open-source, cross-platform clones of the RPG Maker series exist such as Open RPG Maker, MKXP and EasyRPG, as well as the similar OHRRPGCE and Solarus. The Adventure Game Studio editor is not yet ported to Linux, although games made in it are compatible, and the Wintermute and SLUDGE adventure game engines are available. ZGameEditor, Novashell, GB Studio, and the ZZT inspired MegaZeux are also options. Versions of Mugen were made available for Linux, and open-source re-implementations such as IKEMEN Go are compatible. The JavaScript based Ct.js Pixelbox.js, and Superpowers
are also options.
Level editors
Various level editors exists for Linux, such as wxqoole, GtkRadiant, TrenchBroom and J.A.C.K. for the id Tech engines and related, Eureka, SLADE and ReDoomEd for the Doom engine, and the general purpose tile map editors LDtk, Ogmo, and Tiled.
Debuggers
Several game development tools have been available for Linux, including GNU Debugger, LLDB, Valgrind, glslang and others. VOGL, a debugger for OpenGL was released on 12 March 2014.
Available interfaces and SDKs
There are multiple interfaces and Software Development Kits available for Linux, and almost all of them are cross-platform. Most are free and open-source software subject to the terms of the zlib License, making it possible to static link against them from fully closed-source proprietary software. One difficulty due to this abundance of interfaces, is the difficulty for programmers to choose the best suitable audio API for their purpose. The main developer of the PulseAudio project, Lennart Poettering, commented on this issue.
Physics engines, audio libraries, that are available as modules for game engines, have been available for Linux for a long time.
The book Programming Linux Games covers a couple of the available APIs suited for video game development for Linux, while The Linux Programming Interface covers the Linux kernel interfaces in much greater detail.
Available middleware
Beside majority of the software which acts as an interface to various subsystems of the operating system, there is also software which can be simply described as middleware. A multitude of companies exist worldwide, whose main or only product is software that is meant to be licensed and integrated into a game engine. Their primary target is the video game industry, but the film industry also utilizes such software for special effects. Some very few well known examples are
classical physics: Havok, Newton Game Dynamics and PhysX
audio: Audiokinetic Wwise, FMOD
other: SpeedTree
A significant share of the available middleware already runs natively on Linux, only a very few run exclusively on Linux.
Available IDEs and source code editors
Numerous source code editors and IDEs are available for Linux, among which are Visual Studio Code, Sublime Text, Code::Blocks, Qt Creator, Emacs, or Vim.
Multi-monitor
A multi-monitor setup is supported on Linux at least by AMD Eyefinity & AMD Catalyst, Xinerama and RandR on both X11 and Wayland. Serious Sam 3: BFE is one example of a game that runs natively on Linux and supports very high resolutions and is validated by AMD to support their Eyefinity. Civilization V is another example, it even runs on a "Kaveri" desktop APU in 3x1 portrait mode.
Voice over IP
The specifications of the Mumble protocol are freely available and there are BSD-licensed implementations for both servers and clients. The positional audio API of Mumble is supported by e.g. Cube 2: Sauerbraten.
Wine
Wine is a compatibility layer that provides binary compatibility and makes it possible to run software, that was written and compiled for Microsoft Windows, on Linux. The Wine project hosts a user-submitted application database (known as Wine AppDB) that lists programs and games along with ratings and reviews which detail how well they run with Wine. Wine AppDB also has a commenting system, which often includes instructions on how to modify a system to run a certain game which cannot run on a normal or default configuration. Many games are rated as running flawlessly, and there are also many other games that can be run with varying degrees of success. The use of Wine for gaming has proved controversial in the Linux community as some feel it is preventing, or at least hindering, the further growth of native gaming on the platform.
Emulators
There are numerous emulators for Linux. There are also APIs, virtual machines, and machine emulators that provide binary compatibility:
Anbox and Waydroid for the Android operating system;
Basilisk II for the 68040 Mac;
DOSBox and DOSEMU for MS-DOS and compatibles;
DeSmuME and melonDS for the Nintendo DS;
Dolphin for the GameCube, Wii, and the Triforce;
FCEUX, Nestopia and TuxNES for the Nintendo Entertainment System;
Flashpoint for Adobe Flash;
Frotz for Z-Machine text adventures;
Fuse for the Sinclair ZX Spectrum;
Hatari for the Atari ST, STe, TT and Falcon;
gnuboy for the Nintendo Game Boy and Game Boy Color;
MAME for arcade games (and previously MESS for multiple hardware platforms);
Mednafen and Xe emulating multiple hardware platforms including some of the above;
Mupen64Plus and the no longer actively developed original Mupen64 for the Nintendo 64;
PCSX-Reloaded, pSX and the Linux port of ePSXe for the PlayStation;
Neko Project for the NEC PC-9801;
PCSX2 for the PlayStation 2;
PPSSPP for the PlayStation Portable;
ScummVM for LucasArts and various other adventure games;
SheepShaver for the PowerPC Macintosh;
Snes9x, higan and ZSNES for the Super NES;
Stella for the Atari 2600;
UAE for the Amiga;
VICE for the Commodore 64, 128, VIC-20, Plus/4 and PET;
VisualBoyAdvance, mGBA and Boycott Advance for the Game Boy Advance;
Mini vMac and the no longer actively developed original vMac for the 680x0 Macintosh;
Linux homebrew on consoles
Linux has been ported to several game consoles, including the Xbox, PlayStation 2, PlayStation 3, PlayStation 4, GameCube, and Wii which allows game developers without an expensive game development kit to access console hardware. Several gaming peripherals also work with Linux.
Types of Linux gaming
Linux gaming can be divided into a number of sub-categories.
Libre gaming
Libre gaming is a form of Linux gaming that emphasizes libre software, which often includes levels and assets as well as code.
Native gaming
Native gaming is a form of Linux gaming that emphasizes using only native games or ports and not using emulators or compatibility layers.
DRM-free gaming
DRM-free gaming is a form of Linux gaming that emphasizes boycotting DRM technologies. This can include buying games from GOG.com, certain Humble Bundles or itch.io and avoiding Steam and similar services.
Terminal gaming
Terminal gaming is the playing of text-based games from within a console, often programmed within Bash or using libraries such as ncurses.
Retro gaming
Retrogaming is the playing of older games using emulators such as MAME or Dosbox, compatibility layers such as Wine and Proton, engine reimplementations and source ports, or even older Linux distributions (including live CDs and live USB, or virtual machines), original binaries,
and period hardware.
Live gaming
A number of games can be played from live distributions such as Knoppix, allowing easy access for users unwilling to fully commit to Linux. Certain live distros have specially targeted gamers, such as SuperGamer and Linux-Gamers.
Browser gaming
Browser gaming is the act of playing online games through a web browser, which has the advantage of largely being platform independent. The same largely applies to social network games hosted on social media sites. Older games were largely based on Adobe Flash, while modern ones are mostly HTML5.
Cloud gaming
Cloud gaming is the streaming of games from a central server onto a desktop client. This is another way to play games on Linux that are not natively supported, although some cloud services, such as the erstwhile Google Stadia, are hosted on Linux and Android servers. GamingAnywhere is an open source implementation.
On Windows
Although less exploited than the reverse, as few programs are Linux exclusive, support does exist for running Linux binaries from Windows. The Windows Subsystem for Linux allows the running of both command line and graphical Linux applications from Windows 10 and Windows 11. An earlier implementation is Cygwin, started by Cygnus Solutions and later maintained by Red Hat, although it has limited hardware access and required adaptation. The use of Wine can even allow for the running of Windows games on Linux from Windows. The LibTAS library for tool assisted speedruns currently recommends WSL to run on Windows. Naughty Dog meanwhile have used Cygwin to run old command-line tools for use in their game development, which is a broader use for the platform. As with running Windows applications on Linux, there is controversy over whether running Linux applications on Windows will dilute interest in Linux as distinct platform, though it has speciality uses.
Android gaming
Originally derived from Linux, the Android mobile operating system has a distinct and popular gaming ecosystem. It has also been used as the base for several game consoles, such as the Nvidia Shield Portable and the Ouya. Popular games include Pokemon Go, Genshin Impact, League of Legends: Wild Rift, Dead Cells and Call of Duty: Mobile. Certain games, such as Minecraft, Stardew Valley, and Papers Please, are available for both Android and desktop Linux.
ChromeOS gaming
ChromeOS is another Linux derived operating system by Google for its Chromebooks, and it too has a dedicated gaming ecosystem. Partly owing to a lack of high end graphics hardware, it is especially oriented towards cloud gaming via services like GeForce Now and Xbox Cloud Gaming, with models featuring Nvidia GPUs ultimately being cancelled. Numerous games for Android have also been made compatible with ChromeOS, as well as a standard Linux games, Windows games via Wine or Proton, and with browser games also being popular. A version of Steam has been in development for ChromeOS, with third party launchers also available such as the Heroic Games Launcher for the Epic Games Store. Popular titles include Among Us, Genshin Impact, Alto's Odyssey, Roblox, and Fortnite. Skepticism remains for using ChromeOS and Chromebooks as gaming machines.
BSD gaming
Owing to a common Unix-like heritage and free software ethos, many games for Linux are also ported to BSD variants or can be run using compatibility layers such as Linuxulator. BSDi had partnered with Loki Software to ensure its Linux ports ran on FreeBSD. The Mizutamari launcher exists to facilitate running Windows games through Wine, which can still be used standalone. A 2011 benchmark by Phoronix even found certain speed advantages over running games on Linux itself, comparing PC-BSD 8.2 to Ubuntu 11.04. Most BSD systems come with the same pack in desktop games as Linux. The permissive licensing of BSD has also lead to its inclusion in the system software of several game consoles, such as the Sony PlayStation line and the Nintendo Switch.
OpenHarmony gaming
HarmonyOS with custom kernel and OpenHarmony-Oniro based operating systems distros of these newer platforms has a dedicated gaming ecosystem with compatibilities with third-party Linux libraries by developers on Linux kernel subsystem such as musl-libc of C standard library that targets the Linux syscall and POSIX APIs compatibility for native compatible games as well as limited virtual machines such as Android-based sandboxed ones.
Unix gaming
A further niche exists for running games, either through ports or lxrun, on Solaris and derivatives such as OpenIndiana, Darwin distributions such as PureDarwin, Coherent, SerenityOS, Redox OS, ToaruOS, Xv6, Fiwix, or on Minix and Hurd based systems. There has been some cross-pollination with purely proprietary Unix derivatives, such as AIX, QNX, Domain/OS, HP-UX, IRIX (see here), Xenix, SCO Unix, Unixware, Tru64 UNIX, LynxOS (which features inbuilt Linux compatibility), Ultrix, OpenVMS, z/OS UNIX System Services, and even A/UX. The games Doom and Quake were developed by id Software on NeXTStep, a forerunner of modern macOS, before being ported to DOS and back to numerous other Unix variants. This involved reaching out to numerous Unix vendors to supply machines to use in the build and testing process.
See also
Directories and lists
Free Software Directory
List of emulators
List of open-source video games
List of video game console emulators
Linux gaming software
Direct3D (alternative implementation)
Lutris
PlayOnLinux
Proton (software)
Steam (service)
Vulkan
Wine (software)
Other articles
Linux for PlayStation 2
Sega Lindbergh
References
Video gaming
Video game platforms | Video games and Linux | Technology | 7,838 |
858,914 | https://en.wikipedia.org/wiki/Al-Battani | Abū ʿAbd Allāh Muḥammad ibn Jābir ibn Sinān al-Raqqī al-Ḥarrānī aṣ-Ṣābiʾ al-Battānī (), usually called al-Battānī, a name that was in the past Latinized as Albategnius, (before 858929) was an astronomer, astrologer, geographer and mathematician, who lived and worked for most of his life at Raqqa, now in Syria. He is considered to be the greatest and most famous of the astronomers of the medieval Islamic world.
Al-Battānī's writings became instrumental in the development of science and astronomy in the west. His (), is the earliest extant (astronomical table) made in the Ptolemaic tradition that is hardly influenced by Hindu or Sasanian astronomy. Al-Battānī refined and corrected Ptolemy's Almagest, but also included new ideas and astronomical tables of his own. A handwritten Latin version by the Italian astronomer Plato Tiburtinus was produced between 1134 and 1138, through which medieval astronomers became familiar with al-Battānī. In 1537, a Latin translation of the was printed in Nuremberg. An annotated version, also in Latin, published in three separate volumes between 1899 and 1907 by the Italian Orientalist Carlo Alfonso Nallino, provided the foundation of the modern study of medieval Islamic astronomy.
Al-Battānī's observations of the Sun led him to understand the nature of annular solar eclipses. He accurately calculated the Earth's obliquity (the angle between the planes of the equator and the ecliptic), the solar year, and the equinoxes (obtaining a value for the precession of the equinoxes of one degree in 66 years). The accuracy of his data encouraged Nicolaus Copernicus to pursue ideas about the heliocentric nature of the cosmos. Al-Battānī's tables were used by the German mathematician Christopher Clavius in reforming the Julian calendar, and the astronomers Tycho Brahe, Johannes Kepler, Galileo Galilei and Edmund Halley all used Al-Battānī's observations.
Al-Battānī introduced the use of sines and tangents in geometrical calculations, replacing the geometrical methods of the Greeks. Using trigonometry, he created an equation for finding the (the direction which Muslims need to face during their prayers). His equation was widely used until superseded by more accurate methods, introduced a century later by the polymath al-Biruni.
Life
Al-Battānī, whose full name was , and whose Latinized name was , was born before 858 in Harran in Bilād ash-Shām (Islamic Syria), southeast of the modern Turkish city of Urfa. He was the son of Jabir ibn Sinan al-Harrani, a maker of astronomical instruments. The epithet suggests that his family belonged to the pagan Sabian sect of Harran, whose religion featured star worship, and who had inherited the Mesopotamian legacy of an interest in mathematics and astronomy. His contemporary, the polymath Thābit ibn Qurra, was also an adherent of Sabianism, which died out during the 11th century.
Although his ancestors were likely Sabians, al-Battānī was a Muslim, as shown by his first name. Between 877 and 918/19 he lived in Raqqa, now in north central Syria, which was an ancient Roman settlement beside the Euphrates, near Harran. During this period he also lived in Antioch, where he observed a solar and a lunar eclipse in 901. According to the Arab biographer Ibn al-Nadīm, the financial problems encountered by al-Battānī in old age forced him to move from Raqqa to Baghdad.
Al-Battānī died in 929 at Qasr al-Jiss, near Samarra, after returning from Baghdad where he had resolved an unfair taxation grievance on behalf of a clan from Raqqa.
Astronomy
Al-Battānī is considered to be the greatest and most famous of the known astronomers of the medieval Islamic world. He made more accurate observations of the night sky than any of his contemporaries, and was the first of a generation of new Islamic astronomers that followed the founding of the House of Wisdom in the 8th century. His meticulously described methods allowed others to assess his results, but some of his explanations about the movements of the planets were poorly written, and have mistakes.
Sometimes referred to as the "Ptolemy of the Arabs", al-Battānī's works reveal him to have been a devout believer in Ptolemy's geocentric model of the cosmos. He refined the observations found in Ptolemy's , and compiled new tables of the Sun and the Moon, previously long accepted as authoritative. Al-Battānī established his own observatory at Raqqa. He recommended that the astronomical instruments there were greater than in size. Such instruments, being larger—and so having scales capable of measuring smaller values—were capable of greater precision than had previously been achieved. Some of his measurements were more accurate than those taken by the Polish astronomer and mathematician Nicolaus Copernicus during the Renaissance. One reason for this is thought to be that al-Battānī's location for his observations at Raqqa was closer to the Earth's equator, so that the ecliptic and the Sun, being higher in the sky, were less susceptible to atmospheric refraction. The careful construction and alignment of his astronomical instruments enabled him to achieve an accuracy of observations of equinoxes and solstices that had previously been unknown.
Al-Battānī was one of the first astronomers to observe that the distance between the Earth and the Sun varies during the year, which led him to understand the reason why annular solar eclipses occur. He saw that the position in the sky at which the angular diameter of the Sun appeared smallest was no longer located where Ptolemy had stated it should be, and that since Ptolemy's time, the longitudinal position of the apogee had increased by 16°47'.
Al-Battānī was an excellent observer. He improved Ptolemy's measurement of the obliquity of the ecliptic (the angle between the planes of the equator and the ecliptic), producing a value of 23° 35'; the accepted value is around 23°.44. Al-Battānī obtained the criterion for observation of the lunar crescent—i.e., if the longitude difference between the Moon and the Sun is greater than 13° 66˝ and the Moon's delay after sunset is more than 43.2 minutes, the crescent will be visible. His value for the solar year of 365 days, 5 hours, 46 minutes and 24 seconds, is 2 minutes and 22 seconds from the accepted value.
Al-Battānī observed changes in the direction of the Sun's apogee, as recorded by Ptolemy, and that as a result, the equation of time was subject to a slow cyclical variation. His careful measurements of when the March and September equinoxes took place allowed him to obtain a value for the precession of the equinoxes of 54.5" per year, or 1 degree in 66 years, a phenomenon that he realised was altering the Sun's annual apparent motion through the zodiac constellations.
It was impossible for al-Battānī, who adhered to the ideas of a stationary Earth and geocentricism, to understand the underlying scientific reasons for his observations or the importance of his discoveries.
Mathematics
One of al-Battani's greatest contributions was his introduction of the use of sines and tangents in geometrical calculations, especially spherical trigonometric functions, to replace Ptolemy's geometrical methods. Al-Battānī's methods involved some of the most complex mathematics developed up to that time. He was aware of the superiority of trigonometry over geometrical chords, and demonstrated awareness of a relation between the sides and angles of a spherical triangle, now given by the expression:
Al-Battānī produced a number of trigonometrical relationships:
, where .
He also solved the equation
,
discovering the formula
Al-Battānī used the Iranian astronomer Habash al-Hasib al-Marwazi's idea of tangents to develop equations for calculating and compiling tables of both tangents and cotangents. He discovered their reciprocal functions, the secant and cosecant, and produced the first table of cosecants for each degree from 1° to 90°, which he referred to as a "table of shadows", in reference to the shadow produced on a sundial.
Using these trigonometrical relationships, al-Battānī created an equation for finding the , which Muslims face in each of the five prayers they practice every day. The equation he created did not give accurate directions, as it did not take into account the fact that Earth is a sphere. The relationship he used was precise enough only for a person located in (or close to) Mecca, but was still a widely used method at the time. Al-Battānī's equation for , the angle of the direction of a place towards Mecca is given by:
where is the difference between the longitude of the place and Mecca, and is the difference between the latitude of the place and Mecca.
Al-Battānī's equation was superseded a century after it was first used, when the polymath al-Biruni summarized several other methods to produce results that were more accurate than those that could be obtained using al-Battānī's equation.
A small work on trigonometry, ("Summary of the principles for establishing sines") is known. Once attributed to the Iranian astronomer Kushyar Gilani by the German orientalist Carl Brockelmann, it is a fragment of al-Battānī's . The manuscript is extant in Istanbul as MS Carullah 1499/3. The authenticity of this work has been questioned, as scholars believe al-Battānī would have not have included for "sines" in the title.
Works
Al-Battānī's ( or , "Book of Astronomical Tables"), written in around 900, and also known as the (), is the earliest extant made in the Ptolemaic tradition that is hardly influenced by Hindu or Sasanian–Iranian astronomy. It corrected mistakes made by Ptolemy and described instruments such as horizontal and vertical sundials, the triquetrum, the mural instrument, and a quadrant instrument. Ibn al-Nadim wrote that al-Battānī's existed in two different editions, "the second being better than the first". In the west, the work was sometimes called the Sabean Tables.
The work, consisting of 57 chapters and additional tables, is extant (in the manuscript árabe 908, held in El Escorial), copied in Al-Andalus during the 12th or 13th century. Incomplete copies exist in other western European libraries. Much of the book consists of instructions for using the attached tables. Al-Battānī used an Arabic translation of the Almagest made from Syriac, and used few foreign terms. He copied some data directly from Ptolemy's Handy Tables, but also produced his own. His star table of 880 used around half the stars found in the then 743-year-old Almagest. It was made by increasing Ptolemy's stellar longitudes, to allow for the different positions of the stars, now known to be caused by precession.
Other based on include those written by Kushyar Gilani, Alī ibn Ahmad al-Nasawī, Abū Rashīd Dāneshī, and Ibn al-Kammad.
The first version in Latin from the Arabic was made by the English astronomer Robert of Ketton; this version is now lost. A Latin edition was also produced by the Italian astronomer Plato Tiburtinus between 1134 and 1138. Medieval astronomers became quite familiar with al-Battānī through this translation, renamed ("On stellar motion"). It was also translated from Arabic into Spanish during the 13th century, under the orders of Alphonso X of Castile; a part of the manuscript is extant.
The appears to have been widely used until the early 12th century. One 11th-century , now lost, was compiled by al-Nasawī. That it was based on al-Battānī can be inferred from the matching values for the longitudes of the solar and planetary apogees. Al-Nasawī had as a young man written astronomical tables using data obtained from al-Battānī's , but then discovered the data he used had been superseded by more accurately made calculations.
The invention of movable type in 1436 made it possible for astronomical works to be circulated more widely, and a Latin translation of the was printed in Nuremberg in 1537 by the astronomer Regiomontanus, which enabled Al-Battānī's observations to become accessible at the start of the scientific revolution in astronomy. The was reprinted in Bologna in 1645; the original document is preserved at the Vatican Library in Rome.
The Latin translations, including the printed edition of 1537, made the influential in the development of European astronomy. A chapter of the also appeared as a separate work, ("On the accurate determination of the quantities of conjunctions [according to the latitudes of the planets]").
Al-Battānī's work was published in three volumes, in 1899, 1903, and 1907, by the Italian Orientalist Carlo Alfonso Nallino, who gave it the title . Nallino's edition, although in Latin, is the foundation of the modern study of medieval Islamic astronomy.
(, “The book of the science of the ascensions of the signs of the zodiac in the spaces between the quadrants of the celestial sphere”) may have been about calculations relating to the zodiac. The work is mentioned in a work by Ibn al-Nadim, and is probably identical with chapter 55 of al-Battānī's . It provided methods of calculation needed in the astrological problem of finding (directio).
Other works
("On the astrological indications of conjunctions and eclipses") is a treatise on horoscopes and astrology in connection with conjunctions of Saturn and Jupiter that occurred during the earliest period of Islam. The extant manuscript is held in the İsmail Saib Library at Ankara University.
(, "Commentary on Ptolemy's Tetrabiblos") is a commentary on the in the version of Abu as-Salt. Al-Battānī mentions two earlier treatises that are likely identical to two chapters of the . It is extant in the manuscripts Berlin Spr. 1840 (Ahlwardt #5875) and Escorial árabe 969/2.
(, "Four discourses") was a commentary on Ptolemy's , known as the . The 10th-century encyclopedist Ibn Nadim in his , lists al-Battānī among a number of authors of commentaries on this work.
(, "Knowledge of the rising-places of the zodiacal signs").
(), an astrological treatise on the four "quarters of the sphere".
Legacy
Medieval period
The was renowned by medieval Islamic astronomers; the Arab polymath al-Bīrūnī wrote ("Elucidation of genius in al-Battānī's Zīj"), now lost.
Al-Battānī's work was instrumental in the development of science and astronomy in the west. Once it became known, it was used by medieval European astronomers and during the Renaissance. He influenced Jewish rabbis and philosophers such as Abraham ibn Ezra and Gersonides. The 12th-century scholar Moses Maimonides, the intellectual leader of medieval Judaism, closely followed al-Battānī. Hebrew editions of the were produced by the 12th-century Catalan astronomer Abraham bar Hiyya and the 14th-century French mathematician Immanuel Bonfils.
Copernicus referred to "al-Battani the Harranite" when discussing the orbits of Mercury and Venus. He compared to his own value for the sidereal year with those obtained by al-Battānī, Ptolemy and a value he attributed to the 9th-century scholar Thabit ibn Qurra. The accuracy of al-Battānī's observations encouraged Copernicus to pursue his ideas about the heliocentric nature of the cosmos, and in the book that initiated the Copernican Revolution, the , al-Battānī is mentioned 23 times.
16th and 17th centuries
Al-Battānī's tables were used by the German mathematician Christopher Clavius in reforming the Julian calendar, leading to it being replaced by the Gregorian calendar in 1582. The astronomers Tycho Brahe, Giovanni Battista Riccioli, Johannes Kepler and Galileo Galilei cited Al-Battānī or his observations. His almost exactly correct value obtained for the Sun's eccentricity is better than the values determined by both Copernicus and Brahe.
The lunar crater Albategnius was named in his honour during the 17th century. Like many of the craters on the Moon's near side, it was given its name by Riccioli, whose 1651 nomenclature system has become standardized.
In the 1690s, the English physicist and astronomer Edmund Halley, using Plato Tiburtius's translation of al-Battānī's , discovered that the Moon's speed was possibly increasing. Halley researched the location of Raqqa, where al-Battānī's observatory had been built, using the astronomer's calculations for the solar obliquity, the interval between successive autumnal equinoxes and several solar and lunar eclipses seen from Raqqa and Antioch. From this information, Halley derived the mean motion and position of the Moon for the years 881, 882, 883, 891, and 901. To interpret his results, Halley was dependent upon on knowing the location of Raqqa, which he was able to do once he had corrected the accepted value for the latitude of Aleppo.
18th century – present
Al-Battānī's observations of eclipses were used by the English astronomer Richard Dunthorne to determine a value for the increasing speed of the Moon in its orbit, he calculated that the lunar longitude was changing at a rate of 10 arcseconds per century.
Al-Battānī's data is still used by geophysicists.
See also
List of Arab scientists and scholars
Notes
References
Sources
(PDF version)
Versions of
manuscripts
– Gerard of Abbeville Manuscript: Latin 16657 ()
13761475 – Manuscript:Vat.lat.3098 ()
14th century – Manuscript Latin 7266 ()
19th, 20th century publications
Further reading
929 deaths
Year of birth uncertain
9th-century Arab people
10th-century Arab people
9th-century astrologers
9th-century astronomers
9th-century mathematicians
9th-century people from the Abbasid Caliphate
10th-century astrologers
10th-century astronomers
10th-century mathematicians
Astronomers from the Abbasid Caliphate
Astrologers of the medieval Islamic world
People from Harran
Scientists who worked on qibla determination
Mathematicians from the Abbasid Caliphate
Sabian scholars from the Abbasid Caliphate
Equinoxes | Al-Battani | Astronomy | 3,931 |
23,275,266 | https://en.wikipedia.org/wiki/CAR-226%2C086 | CAR-226,086 is a potent anticholinergic deliriant drug with a fairly long duration of action, related to the chemical warfare agent 3-quinuclidinyl benzilate (QNB). It was developed under contract to Edgewood Arsenal during the 1960s as part of the US military chemical weapons program, during research to improve upon the properties of earlier agents such as QNB.
CAR-226,086 was relatively poorly researched compared to other compounds in the series, but notably was found to have the highest central to peripheral effects ratio out of all compounds tested, even higher than that of other CNS-selective agents such as EA-3443.
See also
EA-3167
N-Methyl-3-piperidyl benzilate
N-Ethyl-3-piperidyl benzilate
Ditran
References
Centrally selective drugs
Deliriants
Incapacitating agents
Muscarinic antagonists
Phenylcyclopentylglycolate esters
Tropanes | CAR-226,086 | Chemistry | 208 |
5,197,381 | https://en.wikipedia.org/wiki/Rovibronic%20coupling | Rovibronic coupling, also known as rotation/vibration-electron coupling, denotes the simultaneous interactions between rotational, vibrational, and electronic degrees of freedom in a molecule. When a rovibronic transition occurs, the rotational, vibrational, and electronic states change simultaneously, unlike in rovibrational coupling. The coupling can be observed using spectroscopy, and is most easily seen in the Renner–Teller effect in which a linear polyatomic molecule is in a degenerate electronic state and bending vibrations will cause a large rovibronic coupling.
See also
Afterglow plasma
Vibronic coupling
References
Rotation
Molecular vibration
Spectroscopy | Rovibronic coupling | Physics,Chemistry,Astronomy | 131 |
964,312 | https://en.wikipedia.org/wiki/12AX7 | 12AX7 (also known as ECC83) is a miniature dual-triode vacuum tube with high voltage gain. Developed around 1946 by RCA engineers in Camden, New Jersey, under developmental number A-4522, it was released for public sale under the 12AX7 identifier on September 15, 1947.
The 12AX7 was originally intended as replacement for the 6SL7 family of dual-triode amplifier tubes for audio applications. As a popular choice for guitar tube amplifiers, its ongoing use in such equipment makes it one of the few small-signal vacuum tubes in continuous production since it was introduced.
History
The 12AX7 is a twin triode basically composed of two of the triodes from a 6AV6, a double diode triode. The 6AV6 is a miniature repackaging (with just a single cathode) of the triode and twin diodes from the octal 6SQ7 (a double-diode triode used in AM radios), which itself is very similar to the older type 75 triode-diode dating from 1930.
Application
The 12AX7 is a high-gain (typical amplification factor 100), low-plate-current triode best suited for low-level audio voltage amplification. In this role it is widely used for the preamplifier (input and mid-level) stages of audio amplifiers. It has relatively high Miller capacitance, making it unsuitable for radio-frequency use.
Typically a 12AX7 triode is configured with a high-value plate resistor, 100 kohms in most guitar amps and 220 kΩ or more in high-fidelity equipment. Grid bias is most often provided by a cathode resistor. If the cathode resistor is unbypassed, negative feedback is introduced and each half of a 12AX7 provides a typical voltage gain of about 30; the amplification factor is basically twice the maximum stage gain, as the plate impedance must be matched. Thus half the voltage is across the tube at rest, half across the load resistor. The cathode resistor can be bypassed to reduce or eliminate AC negative feedback and thereby increase gain; maximum gain is about 60 times with a 100k plate load, and a center biased and bypassed cathode, and higher with a larger plate load.
Where = voltage gain, is the amplification factor of the valve, is the internal plate resistance, is the cathode resistor and is the parallel combination of (external plate resistor) and . If the cathode resistor is bypassed, use .
The initial “12” in the designator implies a 12-volt heater requirement; however, the tube has a center-tapped heater so it can be used in either 6.3-V or 12.6-V heater circuits.
Similar twin-triode designs
The 12AX7 is the most common member of what eventually became a large family of twin-triode vacuum tubes, manufactured all over the world, all sharing the same pinout (EIA 9A). Most use heaters which can be optionally wired in series (12.6V, 150 mA) or parallel (6.3V, 300 mA). Other tubes, which in some cases can be used interchangeably in an emergency or for different performance characteristics, include the 12AT7, 12AU7, 12AV7, 12AY7, and the low-voltage 12U7, plus many four-digit EIA series dual triodes. They span a wide range of voltage gain and transconductance. Different versions of each were designed for enhanced ruggedness, low microphonics, stability, lifespan, etc.
Those other designs offer lower voltage gain (traded off for higher plate current) than the 12AX7 (which has a voltage gain or of 100), and are more suitable for high-frequency applications.
Some American designs similar to the 12AX7:
12AD7 (October 10, 1955 - 225mA heater - low hum)
12AT7 (May 20, 1947, dual 6AB4, = 60)
12AU7 (October 18, 1946, dual 6C4, = 17-20)
12AV7 (February 14, 1950 - dual 6BC4, = 37-41)
12AX7 (September 15, 1947 - dual 6DR4, also like octal 6SL7, = 100) dual 12AV6 (6AV6)
12AY7 (December 7, 1948 - = 44, for audio preamp use)
12AZ7 (March 2, 1951 - 225mA heater, = 60)
12DF7 ( = 100, low microphonics)
12DT7 ( = 100)
12DW7 (First triode: = 100, Second triode: = 17)
12U7 ( = 20, for use in automotive radios on 12-volt plate supply)
Although commonly known in Europe by its Mullard–Philips tube designation of ECC83, other European variations also exist including the low-noise versions 12AX7A, 12AD7, 6681, 7025, and 7729; European versions B339, B759, CV492, CV4004, CV8156, CV8222, ECC803, ECC803S, E2164, and M8137; and the lower-gain low-noise versions 5751 and 6851, intended for avionics equipment.
In European usage special-quality valves of some sort were often indicated by exchanging letters and digits in the name: the E83CC was a special-quality ECC83.
In the US a "W" in the designation, as in 12AX7WA, designates the tube as complying with military grade, higher reliability specifications.
The 'E' in the European designation classifies this as having a 6.3 volt heater, whereas the American designation of 12AX7 classifies it as having a 12.6 volt heater. It can, of course, be wired for operation off either voltage.
Manufacturers
versions of the 12AX7/ECC83 are available from the following manufacturers:
In Russia: New Sensor, which produces tubes under the Sovtek, Electro-Harmonix, Svetlana, Tung-Sol, and Mullard brands
In Slovakia: JJ Electronic (annual production of approximately two million units)
In China: Hengyang Electronics, Tubes sold under Psvane and TAD brand names. Company owns its independent manufacturing facility in Southern China (former Guiguang tube factory) and recently they acquired former small signal tube manufacturing line from Tianjin Quanzheng factory (TJ Full Music)
Gallery
See also
List of vacuum tubes
References
External links
Duncan's Amps TDSL.
Several tube datasheets.
Reviews of 12ax7 tubes.
The 12AX7 tube.
12AX7/ECC83 page (with datasheet) at JJ Electronic
Vacuum tubes
Guitar amplification tubes
RCA | 12AX7 | Physics | 1,462 |
71,194,216 | https://en.wikipedia.org/wiki/EU%20Tauri | EU Tauri is a variable star in the equatorial constellation of Taurus. With a brightness that cycles around an apparent visual magnitude of 8.07, it is too faint to be visible to the naked eye. The distance to this star is approximately 3,900 light years based on parallax measurements, but it is drifting closer with a radial velocity of −2.5 km/s. The position of this star near the ecliptic means it is subject to lunar occultations.
The variability of this star was first reported by C. Hoffmeister in 1949, who later reported it as not variable. It was initially classified as an eclipsing binary of the W Ursae Majoris type by F. B. Wood and associates in 1963, based on observations by T. A. Azarnova in 1950–1951. Analysis of photoelectric data by E. F. Guinan in 1966 suggested this is instead a cepheid-type variable with a short pulsation period of about 2.105 days. He refined this period to 2.1051 days in 1972.
A study of the light curve of this and other cepheids in 1981 showed it belongs to a small group with unusually short periods and distinctive behavior. This indicated that EU Tauri may be a "first overtone" pulsator. Gieren and J. M. Matthews in 1987 suggested that the star may instead have two pulsation periods, but this was later refuted. The evidence now mostly supports the idea that the pulsation of the star is in a "radial first overtone mode". The 1% radius variation during a pulsation cycle is relatively small for a star of this class. By 2007, scattered observations over a 35-year time frame indicated that the pulsation period of this s-Cepheid may have changed.
References
Further reading
Cepheid variables
Taurus (constellation)
BD+18 955
038321
027183
Tauri, EU | EU Tauri | Astronomy | 414 |
70,401,123 | https://en.wikipedia.org/wiki/Thaumetopoein | Thaumetopoein is a urticating protein found in the hairs and integument of the caterpillars of the pine processionary (Thaumetopoea pityocampa) and oak processionary (Thaumetopoea processionea).''
It was first identified in 1986 by a group of French scientists at the University of Bordeaux. Attempting to understand the mechanisms responsible for the strong cutaneous reactions provoked when in contact with the caterpillar, the researchers extracted the proteins from the caterpillars' setae. They subsequently isolated thaumetopoein, a small protein formed of two subunits of approximately 13,000 and 15,000 daltons.
Little substantial research has been conducted since the protein's identification. In 2003, Spanish researches analyzed the protein and were able to isolate and identified a major constituent allergen with a molecular weight around 15,000 daltons, which they named Tha p1. In 2012, a separate group of researchers identified a second component, Tha p2.
References
Proteins
Proteins by function | Thaumetopoein | Chemistry | 218 |
71,804,759 | https://en.wikipedia.org/wiki/Lithium%20thiocyanate | Lithium thiocyanate is a chemical compound with the formula LiSCN. It is an extremely hygroscopic white solid that forms the monohydrate and the dihydrate. It is the least stable of the alkali metal thiocyanates due to the large electrostatic deforming field of the lithium cation.
Properties and preparation
Lithium thiocyanate is hygroscopic and forms the anhydrous, monohydrate, and dihydrate, which melts at 274, 60, and 38 °C, respectively. The monohydrate supercools after melting, as it recrystallizes at 36 °C. It is soluble in many organic solvents, such as ethanol, methanol, 1-propanol, and acetone. However, it is insoluble in benzene.
Due to its hygroscopicity, the anhydrous form is hard to prepare. The anhydrous form is usually prepared by the reaction of lithium hydroxide and ammonium thiocyanate, then the water was removed by vacuum, then the resulting solid was dissolved in diethyl ether, followed by adding to petroleum ether to form the ether salt, then it was heated in vacuum at 110 °C to result in the anhydrous salt. The overall reaction is the following:
LiOH + NH4SCN → LiSCN + NH4OH
The ether can be replaced by THF.
Crystallography
The monohydrate has 2 forms, the α form, and the β form; the α form reversibly converts to the β form at 49 °C. The α form has the space group C2/m while the β form has the space group Pnam. More info on its crystallography are listed in the table below.
References
Lithium compounds
Thiocyanates | Lithium thiocyanate | Chemistry | 390 |
1,343,951 | https://en.wikipedia.org/wiki/Seifert%20surface | In mathematics, a Seifert surface (named after German mathematician Herbert Seifert) is an orientable surface whose boundary is a given knot or link.
Such surfaces can be used to study the properties of the associated knot or link. For example, many knot invariants are most easily calculated using a Seifert surface. Seifert surfaces are also interesting in their own right, and the subject of considerable research.
Specifically, let L be a tame oriented knot or link in Euclidean 3-space (or in the 3-sphere). A Seifert surface is a compact, connected, oriented surface S embedded in 3-space whose boundary is L such that the orientation on L is just the induced orientation from S.
Note that any compact, connected, oriented surface with nonempty boundary in Euclidean 3-space is the Seifert surface associated to its boundary link. A single knot or link can have many different inequivalent Seifert surfaces. A Seifert surface must be oriented. It is possible to associate surfaces to knots which are not oriented nor orientable, as well.
Examples
The standard Möbius strip has the unknot for a boundary but is not a Seifert surface for the unknot because it is not orientable.
The "checkerboard" coloring of the usual minimal crossing projection of the trefoil knot gives a Mobius strip with three half twists. As with the previous example, this is not a Seifert surface as it is not orientable. Applying Seifert's algorithm to this diagram, as expected, does produce a Seifert surface; in this case, it is a punctured torus of genus g = 1, and the Seifert matrix is
Existence and Seifert matrix
It is a theorem that any link always has an associated Seifert surface. This theorem was first published by Frankl and Pontryagin in 1930. A different proof was published in 1934 by Herbert Seifert and relies on what is now called the Seifert algorithm. The algorithm produces a Seifert surface , given a projection of the knot or link in question.
Suppose that link has m components ( for a knot), the diagram has d crossing points, and resolving the crossings (preserving the orientation of the knot) yields f circles. Then the surface is constructed from f disjoint disks by attaching d bands. The homology group is free abelian on 2g generators, where
is the genus of . The intersection form Q on is skew-symmetric, and there is a basis of 2g cycles with
equal to a direct sum of the g copies of the matrix
The 2g × 2g integer Seifert matrix
has the linking number in Euclidean 3-space (or in the 3-sphere) of ai and the "pushoff" of aj in the positive direction of . More precisely, recalling that Seifert surfaces are bicollared, meaning that we can extend the embedding of to an embedding of , given some representative loop which is homology generator in the interior of , the positive pushout is and the negative pushout is .
With this, we have
where V∗ = (v(j, i)) the transpose matrix. Every integer 2g × 2g matrix with arises as the Seifert matrix of a knot with genus g Seifert surface.
The Alexander polynomial is computed from the Seifert matrix by which is a polynomial of degree at most 2g in the indeterminate The Alexander polynomial is independent of the choice of Seifert surface and is an invariant of the knot or link.
The signature of a knot is the signature of the symmetric Seifert matrix It is again an invariant of the knot or link.
Genus of a knot
Seifert surfaces are not at all unique: a Seifert surface S of genus g and Seifert matrix V can be modified by a topological surgery, resulting in a Seifert surface S′ of genus g + 1 and Seifert matrix
The genus of a knot K is the knot invariant defined by the minimal genus g of a Seifert surface for K.
For instance:
An unknot—which is, by definition, the boundary of a disc—has genus zero. Moreover, the unknot is the knot with genus zero.
The trefoil knot has genus 1, as does the figure-eight knot.
The genus of a (p,q)-torus knot is (p − 1)(q − 1)/2
The degree of a knot's Alexander polynomial is a lower bound on twice its genus.
A fundamental property of the genus is that it is additive with respect to the knot sum:
In general, the genus of a knot is difficult to compute, and the Seifert algorithm usually does not produce a Seifert surface of least genus. For this reason other related invariants are sometimes useful. The canonical genus of a knot is the least genus of all Seifert surfaces that can be constructed by the Seifert algorithm, and the free genus is the least genus of all Seifert surfaces whose complement in is a handlebody. (The complement of a Seifert surface generated by the Seifert algorithm is always a handlebody.) For any knot the inequality obviously holds, so in particular these invariants place upper bounds on the genus.
The knot genus is NP-complete by work of Ian Agol, Joel Hass and William Thurston.
It has been shown that there are Seifert surfaces of the same genus that do not become isotopic either topologically or smoothly in the 4-ball.
See also
Crosscap number
Arf invariant of a knot
Murasugi sum
Slice genus
References
External links
The SeifertView programme of Jack van Wijk visualizes the Seifert surfaces of knots constructed using Seifert's algorithm.
Geometric topology
Knot theory
Surfaces | Seifert surface | Mathematics | 1,214 |
61,476,013 | https://en.wikipedia.org/wiki/Clean%20Energy%20Institute | The Clean Energy Institute (CEI) is a research institute at the University of Washington. Founded in 2013, the institute maintains several facilities across the university's Seattle campus and supports renewable energy technology research, education, entrepreneurship, and outreach. The institute is under the direction of Daniel T. Schwartz.
History and operations
The Clean Energy Institute is based in the Molecular Engineering and Sciences building at the University of Washington's Seattle campus. It was founded in 2013 with a $6 million grant from the state of Washington for the purposes of supporting solar power and energy storage research and development. This includes research projects led by the university's own academic labs, private companies, and the government.
The institute's primary research facility is the Washington Clean Energy Testbeds (WCET), which opened in 2017 and was funded by an additional $8 million state grant approved by governor Jay Inslee. Located next to University Village near the main campus, the facility allows both academic and private sector users to rent lab space, utilize testing equipment, and consult staff for assistance in their research projects. Equipment at the WCET include battery device testers, solar simulators and solar cell testers, a systems integration lab where users can test devices under real-time or simulated power grids to evaluate energy generation and storage strategies, and a roll-to-roll printer which GeekWire described as "one of the most advanced roll-to-roll systems in the world."
The institute also maintains the Research Training Testbed, which is located in the Nanoengineering and Sciences Building on the university's main campus.
Research
The Clean Energy Institute's main research areas include battery and solar photovoltaic technology as well as grid management. The institute has supported projects relating to perovskites, which have often focused on improving the material properties of thin-film perovskite cells as well as exploring the use of high-throughput manufacturing processes for producing such devices.
Future expansion
In 2018, the state of Washington allocated $20 million to construct a new building on the west side of the UW's Seattle campus called the Center for Advanced Materials and Clean Energy Technologies (CAMCET). The CAMCET building will ultimately house the Clean Energy Institute and the Washington Clean Energy Testbeds as well as the Northwest Institute for Materials Physics, Chemistry, and Technology, and it will include lab and office space for research and collaboration. Construction is scheduled to begin in late 2020, and the building is expected to open by the year 2023.
References
External links
Clean Energy Institute
University of Washington
Energy research institutes
2013 establishments in Washington (state)
Renewable energy in the United States
Research institutes established in 2013 | Clean Energy Institute | Engineering | 544 |
295,511 | https://en.wikipedia.org/wiki/Sound%20quality | Sound quality is typically an assessment of the accuracy, fidelity, or intelligibility of audio output from an electronic device. Quality can be measured objectively, such as when tools are used to gauge the accuracy with which the device reproduces an original sound; or it can be measured subjectively, such as when human listeners respond to the sound or gauge its perceived similarity to another sound.
The sound quality of a reproduction or recording depends on a number of factors, including the equipment used to make it, processing and mastering done to the recording, the equipment used to reproduce it, as well as the listening environment used to reproduce it. In some cases, processing such as equalization, dynamic range compression or stereo processing may be applied to a recording to create audio that is significantly different from the original but may be perceived as more agreeable to a listener. In other cases, the goal may be to reproduce audio as closely as possible to the original.
When applied to specific electronic devices, such as loudspeakers, microphones, amplifiers or headphones sound quality usually refers to accuracy, with higher quality devices providing higher accuracy reproduction. When applied to processing steps such as mastering recordings, absolute accuracy may be secondary to artistic or aesthetic concerns. In still other situations, such as recording a live musical performance, audio quality may refer to proper placement of microphones around a room to optimally use room acoustics.
Digital audio
Digital audio is stored in many formats. The simplest form is uncompressed PCM, where audio is stored as a series of quantized audio samples spaced at regular intervals in time. As samples are placed closer together in time, higher frequencies can be reproduced. According to the sampling theorem, any bandwidth-limited signal (that does not contain a pure sinusoidal component), bandwidth B, can be perfectly described by more than 2B samples per second, allowing perfect reconstruction of the bandwidth-limited analog signal. For example, for human hearing bandwidth between 0 and 20 kHz, audio must be sampled at above 40 kHz. Due to the need for filtering out ultrasonic frequencies resulting from the conversion to an analog signal, in practice slightly higher sample rates are used: 44.1 kHz (CD audio) or 48 kHz (DVD).
In PCM, each audio sample describes the sound pressure at an instant in time with a limited precision. The limited accuracy results in quantization error, a form of noise that is added to the recording. To reduce quantization error, more precision can be used in each measurement at the expense of larger samples (see audio bit depth). With each additional bit added to a sample, quantization error is reduced by approximately 6 dB. For example, CD audio uses 16 bits per sample, and therefore it will have quantization noise approximately 96 dB below the maximum possible sound pressure level (when summed over the full bandwidth)
The amount of space required to store PCM depends on the number of bits per sample, the number of samples per second, and the number of channels. For CD audio, this is 44,100 samples per second, 16 bits per sample, and 2 channels for stereo audio leading to 1,411,200 bits per second. However, this space can be greatly reduced using audio compression. In audio compression, audio samples are processed using an audio codec. In a lossless codec audio samples are processed without discarding information by packing repetitive or redundant samples into a more efficiently stored form. A lossless decoder then reproduces the original PCM with no change in quality. Lossless audio compression typically achieves a 30-50% reduction in file size. Common lossless audio codecs include FLAC, ALAC, Monkey's Audio and others.
If additional compression is required, lossy audio compression such as MP3, Ogg Vorbis or AAC can be used. In these techniques, lossless compression techniques are enhanced by processing audio to reduce the precision of details that are unlikely or impossible for human hearing to perceive using principles from psychoacoustics. After the removal of these details, lossy compression can be applied to the remainder to greatly reduce the file size. Lossy audio compression therefore allows a 75-95% reduction in file size, but runs the risk of potentially reducing audio quality if important information is mistakenly discarded.
See also
Audio system measurements
Comparison of analog and digital recording
Delivered Audio Quality
Hearing-Aid Speech Quality Index (HASQI)
High fidelity
Loudspeaker measurement
Perceptual Evaluation of Audio Quality (PEAQ)
Perceptual Evaluation of Speech Quality (PESQ)
References
Broadcast engineering
Audio engineering | Sound quality | Engineering | 936 |
49,873,908 | https://en.wikipedia.org/wiki/Paradentiscutata%20maritima | Paradentiscutata maritima is a species of fungus. It is characterised by introverted ornamentations on the spore wall; the spore wall structure and germ shield morphology. It was first isolated in northeast Brazil, and can be distinguished by the projections on the outer spore surface.
References
Further reading
Souza, Renata G., et al. "Use of mycorrhizal seedlings on recovery of mined dunes in northeastern Brazil." Pedobiologia 55.6 (2012): 303–309.
da Silva, Danielle Karla Alves, et al. "Diversity of arbuscular mycorrhizal fungi in restinga and dunes areas in Brazilian Northeast." Biodiversity and Conservation 21.9 (2012): 2361–2373.
da Silva, Danielle Karla Alves, et al. "Communities of arbuscular mycorrhizal fungi on a vegetation gradient in tropical coastal dunes." Applied Soil Ecology 96 (2015): 7–17.
External links
MycoBank
Glomeromycota | Paradentiscutata maritima | Biology | 222 |
8,150,510 | https://en.wikipedia.org/wiki/Internal%20rotary%20inspection%20system | Internal rotary inspection system (IRIS) is an ultrasonic method for the nondestructive testing of pipes and tubes. The IRIS probe is inserted into a tube that is flooded with water, and the probe is pulled out slowly as the data is displayed and recorded. The ultrasonic beam allows detection of metal loss from the inside and outside of the tube wall.
Principle of operation
The IRIS probe consists of a rotating mirror that directs the ultrasonic beam into the tube wall. The mirror is driven by a small turbine that is rotated by the pressure of water being pumped in. As the probe is pulled the spinning motion of the mirror results in a helical scan path.
One of the key settings in the procedure is to ensure that the ultrasonic pulse initiates in the very focus point at the center of the tube or pipe. An off-center pulse will show a distorted image of the tube due to the difference in the sound path for either side of the tube wall. For that reason there are centering devices that help the operator to keep the turbine centered at all times.
The transducer utilized for the inspection has to be high frequency, high enough to bounce back at both the inner wall and the outer wall. The frequency range typically used for the piezoelectric transducer is from 10 to 25 MHz.
Features
Field-proven and commonly used in boilers, heat exchangers, and fin-fan tubes.
Often used as a back-up to electromagnetic examination of tubes, to verify calibration and accuracy. Especially useful as a follow-up to remote field testing due to the full sensitivity near tube support structures provided by IRIS.
The IRIS probe must be moved very slowly (approximately 1 inch per second, or 2.5 cm/s), but it produces very accurate results (wall thickness measurements typically accurate to within 0.005 inch, or 0.13 mm).
Before the examination, tubes must be cleaned on the inside to bare metal.
A supply of clean water is needed, typically at a pressure of 60 psi, or 0.4 MPa. Dirt or debris in the water may cause the turbine to jam.
Works for tube diameters of and up. Special centralizing devices are needed for larger diameters.
Works in metal or plastic tubes.
Through-holes are difficult to detect by using this method.
Operates at temperatures above freezing.
Can pass bends, but will not detect defects in bends.
Not sensitive to cracks aligned with tube radius.
References
Sources
Tubing Inspection using Multiple NDT Techniques. By Fathi E. Al-Qadeeb. PDF, 118 kB.
Condition Monitoring - Process Plant Tube Inspection: an Ongoing Commitment by Plant Owners and Operators. By Charles Panos.
NDT and Heat Exchanger Tubes. By Helle H. Rasmussen, Hans Kristensen & Leif Jeppesen.
Nondestructive testing
Ultrasound | Internal rotary inspection system | Materials_science | 582 |
40,566,490 | https://en.wikipedia.org/wiki/Marlon%20Dumas | Marlon Gerardo Dumas Menjivar (born 22 August 1975) is a Honduran computer scientist, and Professor of Software Engineering at the University of Tartu in Estonia, known for his contributions in the field of Business Process Management.
Born in Honduras, Dumas received his PhD in Computer Science at the University of Grenoble in France in 2000. From 2000 to 2009 he was Lecturer at the Queensland University of Technology in Brisbane, Australia. In 2007 he was appointed Professor of Software Engineering at the University of Tartu in Estonia.
In 2004 and 2007 Dumas was awarded the Queensland Government Fellowship to "undertake research on service-oriented software architectures in collaboration with SAP AG."
Dumas is married to an Estonian, whom he has a daughter with.
Publications
Dumas authored and co-authored numerous publications in the field of computer science. Books:
Marlon Dumas, Wil M.P. van der Aalst, Arthur H.M. ter Hofstede (Editors), Process-Aware Information Systems: Bridging People and Software Through Process Technology, John Wiley & Sons, September 2005.
Marlon Dumas, Marcello La Rosa, Jan Mendling, Hajo A. Reijers. Fundamentals of Business Process Management, Springer, February 2013
Articles, a selection:
Zeng, L., Benatallah, B., Dumas, M., Kalagnanam, J., & Sheng, Q. Z. (2003, May). Quality driven web services composition. In Proceedings of the 12th international conference on World Wide Web (pp. 411–421). ACM.
Zeng, Liangzhao, et al. "QoS-aware middleware for web services composition." Software Engineering, IEEE Transactions on 30.5 (2004): 311-327.
References
External links
Marlon Dumas at University of Tartu
1975 births
Living people
Honduran academics
Honduran scientists
Computer scientists
Grenoble Alpes University alumni
Academic staff of Queensland University of Technology
Academic staff of the University of Tartu
Honduran expatriates in Estonia | Marlon Dumas | Technology | 427 |
55,487,307 | https://en.wikipedia.org/wiki/Book%20clasp | A book clasp is a leather or metal element attached to the medieval and early modern book covers, used to protect the book from the penetration of dust and light.
External links
Fasteners
Clasp
Locksmithing | Book clasp | Engineering | 43 |
41,825,123 | https://en.wikipedia.org/wiki/Molecular%20paleontology | Molecular paleontology refers to the recovery and analysis of DNA, proteins, carbohydrates, or lipids, and their diagenetic products from ancient human, animal, and plant remains. The field of molecular paleontology has yielded important insights into evolutionary events, species' diasporas, the discovery and characterization of extinct species.
In shallow time, advancements in the field of molecular paleontology have allowed scientists to pursue evolutionary questions on a genetic level rather than relying on phenotypic variation alone. By applying molecular analytical techniques to DNA in recent animal remains, one can quantify the level of relatedness between any two organisms for which DNA has been recovered. Using various biotechnological techniques such as DNA isolation, amplification, and sequencing scientists have been able to acquire and expand insights into the divergence and evolutionary history of countless recently extinct organisms. In February 2021, scientists reported, for the first time, the sequencing of DNA from animal remains, a mammoth in this instance, over a million years old, the oldest DNA sequenced to date.
In deep time, compositional heterogeneities in carbonaceous remains of a diversity of animals, ranging in age from the Neoproterozoic to the Recent, have been linked to biological signatures encoded in modern biomolecules via a cascade of oxidative fossilization reactions. The macromolecular composition of carbonaceous fossils, some Tonian in age, preserve biological signatures reflecting original biomineralization, tissue types, metabolism, and relationship affinities (phylogeny).
History
The study of molecular paleontology is said to have begun with the discovery by Abelson of 360 million year old amino acids preserved in fossil shells. However, Svante Pääbo is often the one considered to be the founder of the field of molecular paleontology.
The field of molecular paleontology has had several major advances since the 1950s and is a continuously growing field. Below is a timeline showing notable contributions that have been made.
Timeline
mid-1950s: Abelson found preserved amino acids in fossil shells that were about 360 million years old. Produced idea of comparing fossil amino acid sequences with existing organism so that molecular evolution could be studied.
1970s: Fossil peptides are studied by amino acid analysis. Start to use whole peptides and immunological methods.
Late 1970s: Palaeobotanists (can also be spelled as Paleobotanists) studied molecules from well-preserved fossil plants.
1984: The first successful DNA sequencing of an extinct species, the quagga, a zebra-like species.
1991: Published article on the successful extraction of proteins from the fossil bone of a dinosaur, specifically the Seismosaurus.
2005: Scientists resurrect extinct 1918 influenza virus.
2006: Neanderthals nuclear DNA sequence segments begin to be analyzed and published.
2007: Scientists synthesize entire extinct human endogenous retrovirus (HERV-K) from scratch.
2010: A new species of early hominid, the Denisovans, discovered from mitochondrial and nuclear genomes recovered from bone found in a cave in Siberia. Analysis showed that the Denisovan specimen lived approximately 41,000 years ago, and shared a common ancestor with both modern humans and Neanderthals approximately 1 million years ago in Africa.
2013: The first entire Neanderthal genome is successfully sequenced. More information can be found at the Neanderthal genome project.
2013: A 400,000-year-old specimen with remnant mitochondrial DNA sequenced and is found to be a common ancestor to Neanderthals and Denisovans, Homo heidelbergensis.
2013: Mary Schweitzer and colleagues propose the first chemical mechanism explaining the potential preservation of vertebrate cells and soft tissues into the fossil record. The mechanism proposes that free oxygen radicals, potentially produced by redox-active iron, induce biomolecule crosslinking. This crosslinking mechanism is somewhat analogous to the crosslinking that occurs during histological tissue fixation, such as with formaldehyde. The authors also suggest the source of iron to be the hemoglobin from the deceased organism.
2015: A 110,000-year-old fossil tooth containing DNA from Denisovans was reported.
2018: Molecular paleobiologists link polymers of N-, O-, S-heterocycle composition (AGEs/ALEs, as referred to in the cited publication, Wiemann et al. 2018) in carbonaceous fossil remains mechanistically to structural biomolecules in original tissues. Through oxidative crosslinking, a process similar to the Maillard reaction, nucleophilic amino acid residues condense with Reactive Carbonyl Species derived from lipids and sugars. The processes of biomolecule fossilization, identified via Raman spectroscopy of modern and fossil tissues, experimental modelling, and statistical data evaluation, include Advanced Glycosylation and Advanced Lipoxidation.
2019: An independent laboratory of Molecular Paleontologists confirms the transformation of biomolecules through Advanced Glycosylation and Lipoxidation during fossilization. The authors use Synchrotron Fourier-Transform Infrared spectroscopy.
2020: Wiemann and colleagues identify biological signatures reflecting original biomineralization, tissue types, metabolism, and relationship affinity (phylogeny) in preserved compositional heterogeneities of a diversity of carbonaceous animal fossils. This is the first large-scale analysis of fossils ranging in age from the Neoproterozoic to the Recent, and the first published record of biological signals found in complex organic matter. The authors rely on statistical analyses of a uniquely large Raman spectroscopy data set.
2021: Geochemists find tissue type signals in the composition of carbonaceous fossils dating back to the Tonian, and apply these signals to identify epibionts. The authors use Raman spectroscopy.
2022: Raman spectroscopy data revealing patterns in the fossilization of structural biomolecules have been replicated with Fourier-Transform Infrared spectroscopy and a diversity of different Raman instruments, filters, and excitation sources.
2023: The first in-depth chemical description of how original, biological cells and tissues fossilize is published. Importantly, the study shows that the free oxygen radical hypothesis (proposed by Mary Schweitzer and colleagues in 2013) is in many cases identical to the AGE/ALE formation hypothesis (proposed by Jasmina Wiemann and colleagues in 2018). The combined hypotheses, along with thermal maturation and carbonization, form a loose framework for biological cell and tissue fossilization.
The quagga
The first successful DNA sequencing of an extinct species was in 1984, from a 150-year-old museum specimen of the quagga, a zebra-like species. Mitochondrial DNA (also known as mtDNA) was sequenced from desiccated muscle of the quagga, and was found to differ by 12 base substitutions from the mitochondrial DNA of a mountain zebra. It was concluded that these two species had a common ancestor 3-4 million years ago, which is consistent with known fossil evidence of the species.
Denisovans
The Denisovans of Eurasia, a hominid species related to Neanderthals and humans, was discovered as a direct result of DNA sequencing of a 41,000-year-old specimen recovered in 2008. Analysis of the mitochondrial DNA from a retrieved finger bone showed the specimen to be genetically distinct from both humans and Neanderthals. Two teeth and a toe bone were later found to belong to different individuals with the same population. Analysis suggests that both the Neanderthals and Denisovans were already present throughout Eurasia when modern humans arrived. In November 2015, scientists reported finding a fossil tooth containing DNA from Denisovans, and estimated its age at 110,000-years-old.
Mitochondrial DNA analysis
The mtDNA from the Denisovan finger bone differs from that of modern humans by 385 bases (nucleotides) in the mtDNA strand out of approximately 16,500, whereas the difference between modern humans and Neanderthals is around 202 bases. In contrast, the difference between chimpanzees and modern humans is approximately 1,462 mtDNA base pairs. This suggested a divergence time around one million years ago. The mtDNA from a tooth bore a high similarity to that of the finger bone, indicating they belonged to the same population. From a second tooth, an mtDNA sequence was recovered that showed an unexpectedly large number of genetic differences compared to that found in the other tooth and the finger, suggesting a high degree of mtDNA diversity. These two individuals from the same cave showed more diversity than seen among sampled Neanderthals from all of Eurasia, and were as different as modern-day humans from different continents.
Nuclear genome analysis
Isolation and sequencing of nuclear DNA has also been accomplished from the Denisova finger bone. This specimen showed an unusual degree of DNA preservation and low level of contamination. They were able to achieve near-complete genomic sequencing, allowing a detailed comparison with Neanderthal and modern humans. From this analysis, they concluded, in spite of the apparent divergence of their mitochondrial sequence, the Denisova population along with Neanderthal shared a common branch from the lineage leading to modern African humans. The estimated average time of divergence between Denisovan and Neanderthal sequences is 640,000 years ago, and the time between both of these and the sequences of modern Africans is 804,000 years ago. They suggest the divergence of the Denisova mtDNA results either from the persistence of a lineage purged from the other branches of humanity through genetic drift or else an introgression from an older hominin lineage.
Homo heidelbergensis
Homo heidelbergensis was first discovered in 1907 near Heidelberg, Germany and later also found elsewhere in Europe, Africa, and Asia.
However it was not until 2013 that a specimen with retrievable DNA was found, in a ~400,000 year old femur found in the Sima de los Huesos Cave in Spain. The femur was found to contain both mtDNA and nuclear DNA. Improvements in DNA extraction and library preparation techniques allowed for mtDNA to be successfully isolated and sequenced, however the nuclear DNA was found to be too degraded in the observed specimen, and was also contaminated with DNA from an ancient cave bear (Ursus deningeri) present in the cave. The mtDNA analysis found a surprising link between the specimen and the Denisovans, and this finding raised many questions. Several scenarios were proposed in a January 2014 paper titled "A mitochondrial genome sequence of a hominin from Sima de los Huesos", elucidating the lack of convergence in the scientific community on how Homo heidelbergensis is related to other known hominin groups. One plausible scenario that the authors proposed was that the H. heidelbergensis was an ancestor to both Denisovans and Neanderthals. Completely sequenced nuclear genomes from both Denisovans and Neanderthals suggest a common ancestor approximately 700,000 years ago, and one leading researcher in the field, Svante Paabo, suggests that perhaps this new hominin group is that early ancestor.
Applications
Discovery and characterization of new species
Molecular paleontology techniques applied to fossils have contributed to the discovery and characterization of several new species, including the Denisovans and Homo heidelbergensis. We have been able to better understand the path that humans took as they populated the earth, and what species were present during this diaspora.
De-extinction
It is now possible to revive extinct species using molecular paleontology techniques. This was first accomplished via cloning in 2003 with the Pyrenean ibex, a type of wild goat that became extinct in 2000. Nuclei from the Pyrenean ibex's cells were injected into goat eggs emptied of their own DNA, and implanted into surrogate goat mothers. The offspring lived only seven minutes after birth, due to defects in its lungs. Other cloned animals have been observed to have similar lung defects.
There are many species that have gone extinct as a direct result of human activity. Some examples include the dodo, the great auk, the Tasmanian tiger, the Chinese river dolphin, and the passenger pigeon. An extinct species can be revived by using allelic replacement of a closely related species that is still living. By only having to replace a few genes within an organism, instead of having to build the extinct species' genome from scratch, it could be possible to bring back several species in this way, even Neanderthals.
The ethics surrounding the re-introduction of extinct species are very controversial. Critics of bringing extinct species back to life contend that it would divert limited money and resources from protecting the world's current biodiversity problems. With current extinction rates approximated to be 100 to 1,000 times the background extinction rate, it is feared that a de-extinction program might lessen public concerns over the current mass extinction crisis, if it is believed that these species can simply be brought back to life. As the editors of a Scientific American article on de-extinction pose: Should we bring back the woolly mammoth only to let elephants become extinct in the meantime? The main driving factor for the extinction of most species in this era (post 10,000 BC) is the loss of habitat, and temporarily bringing back an extinct species will not recreate the environment they once inhabited.
Proponents of de-extinction, such as George Church, speak of many potential benefits. Reintroducing an extinct keystone species, such as the woolly mammoth, could help re-balance the ecosystems that once depended on them. Some extinct species could create broad benefits for the environments they once inhabited, if returned. For example, woolly mammoths may be able to slow the melting of the Russian and Arctic tundra in several ways such as eating dead grass so that new grass can grow and take root, and periodically breaking up the snow, subjecting the ground below to the arctic air. These techniques could also be used to reintroduce genetic diversity in a threatened species, or even introduce new genes and traits to allow the animals to compete better in a changing environment.
Research and technology
When a new potential specimen is found, scientists normally first analyze for cell and tissue preservation using histological techniques, and test the conditions for the survivability of DNA. They will then attempt to isolate a DNA sample using the technique described below, and conduct a PCR amplification of the DNA to increase the amount of DNA available for testing. This amplified DNA is then sequenced. Care is taken to verify that the sequence matches the phylogenetic traits of the organism. When an organism dies, a technique called amino acid dating can be used to age the organism. It inspects the degree of racemization of aspartic acid, leucine, and alanine within the tissue. As time passes, the D/L ratio (where "D" and "L" are mirror images of each other) increase from 0 to 1. In samples where the D/L ratio of aspartic acid is greater than 0.08, ancient DNA sequences can not be retrieved (as of 1996).
Mitochondrial DNA vs. nuclear DNA
Mitochondrial DNA (mtDNA) is separate from one's nuclear DNA. It is present in organelles called mitochondria in each cell. Unlike nuclear DNA, which is inherited from both parents and rearranged every generation, an exact copy of mitochondrial DNA gets passed down from mother to her sons and daughters. The benefits of performing DNA analysis with Mitochondrial DNA is that it has a far smaller mutation rate than nuclear DNA, making tracking lineages on the scale of tens of thousands of years much easier. Knowing the base mutation rate for mtDNA, (in humans this rate is also known as the Human mitochondrial molecular clock) one can determine the amount of time any two lineages have been separated. Another advantage of mtDNA is that thousands of copies of it exist in every cell, whereas only two copies of nuclear DNA exist in each cell. All eukaryotes, a group which includes all plants, animals, and fungi, have mtDNA. A disadvantage of mtDNA is that only the maternal line is represented. For example, a child will inherit 1/8 of its DNA from each of its eight great-grandparents, however it will inherit an exact clone of its maternal great-grandmother's mtDNA. This is analogous to a child inheriting only his paternal great-grandfather's last name, and not a mix of all of the eight surnames.
Isolation
There are many things to consider when isolating a substance. First, depending upon what it is and where it is located, there are protocols that must be carried out in order to avoid contamination and further degradation of the sample. Then, handling of the materials is usually done in a physically isolated work area and under specific conditions (i.e. specific Temperature, moisture, etc...) also to avoid contamination and further loss of sample.
Once the material has been obtained, depending on what it is, there are different ways to isolate and purify it. DNA extraction from fossils is one of the more popular practices and there are different steps that can be taken to get the desired sample. DNA extracted from amber-entombed fossils can be taken from small samples and mixed with different substances, centrifuged, incubated, and centrifuged again. On the other hand, DNA extraction from insects can be done by grinding the sample, mixing it with buffer, and undergoing purification through glass fiber columns. In the end, regardless of how the sample was isolated for these fossils, the DNA isolated must be able to undergo amplification.
Amplification
The field of molecular paleontology benefited greatly from the invention of the polymerase chain reaction(PCR), which allows one to make billions of copies of a DNA fragment from just a single preserved copy of the DNA. One of the biggest challenges up until this point was the extreme scarcity of recovered DNA because of degradation of the DNA over time.
Sequencing
DNA sequencing is done to determine the order of nucleotides and genes. There are many different materials from which DNA can be extracted. In animals, the mitochondrial chromosome can be used for molecular study. Chloroplasts can be studied in plants as a primary source of sequence data.
In the end, the sequences generated are used to build evolutionary trees. Methods to match data sets include: maximum probability, minimum evolution (also known as neighbor-joining) which searches for the tree with shortest overall length, and the maximum parsimony method which finds the tree requiring the fewest character-state changes. The groups of species defined within a tree can also be later evaluated by statistical tests, such as the bootstrap method, to see if they are indeed significant.
Limitations and challenges
Ideal environmental conditions for preserving DNA where the organism was desiccated and uncovered are difficult to come by, as well as maintaining their condition until analysis. Nuclear DNA normally degrades rapidly after death by endogenous hydrolytic processes, by UV radiation, and other environmental stressors.
Also, interactions with the organic breakdown products of surrounding soil have been found to help preserve biomolecular materials. However, they have also created the additional challenge of being able to separate the various components in order to be able to conduct the proper analysis on them. Some of these breakdowns have also been found to interfere with the action of some of the enzymes used during PCR.
Finally, one of the largest challenge in extracting ancient DNA, particularly in ancient human DNA, is in contamination during PCR. Small amounts of human DNA can contaminate the reagents used for extraction and PCR of ancient DNA. These problems can be overcome by rigorous care in the handling of all solutions as well as the glassware and other tools used in the process. It can also help if only one person performs the extractions, to minimize different types of DNA present.
See also
Ancient DNA
Ancient protein
Archaeogenetics
Fossils
Human mitochondrial DNA haplogroups
Human Y-chromosome DNA haplogroup
Models of DNA Evolution
Molecular evolution
Paleobiochemistry
Paleobiology
Paleobotany
References
Paleobiology
Evolutionary biology
Subfields of paleontology
Ancient DNA (human)
Fossils | Molecular paleontology | Biology | 4,164 |
30,739,972 | https://en.wikipedia.org/wiki/Microcell-mediated%20chromosome%20transfer | Microcell Mediated Chromosome Transfer (or MMCT) is a technique used in cell biology and genetics to transfer a chromosome from a defined donor cell line into a recipient cell line. MMCT has been in use since the 1970s and has contributed to a multitude of discoveries including tumor, metastasis and telomerase suppressor genes as well as information about epigenetics, x-inactivation, mitochondrial function and aneuploidy. MMCT follows the basic procedure where donor cells (i.e. cells providing one or more chromosomes or fragments to a recipient cell) are induced to multinucleate their chromosomes. These nuclei are then forced through the cell membrane to create microcells, which can be fused to a recipient cell line.
History
The term MMCT was first used by Fournier and Ruddle in 1977. Their method was based on previous work from 1974 by Ege, Ringertz, Veomett and colleagues, synthesizing the techniques used at the time to induce multinucleation in cells, nuclear removal and cell-cell fusions. The next major step in MMCT came during the 1980s when new transfection techniques were utilized to introduce selectable markers onto chromosomes thus making it possible to select for the introduction of specific chromosomes and more easily create defined hybrids.
Procedure
Procedures for MMCT differ slightly but they all require: the induction of multinucleation, enucleation (nuclear removal), and fusion. Multinucleation is usually accomplished through causing prolonged mitotic arrest by colcemid treatment. Certain cells will then "slip" out of mitosis and form multiple nuclei. These nuclei can then be removed using cytochalasin B to disrupt the cytoskeleton and centrifugation in a density gradient to force enucleation. The newly created microcells can then be fused to recipient (target) cells by exposure to poly ethylene glycol, use of Sendai virus, or electrofusion.
Variations now allow construction of "humanized" mice with large pieces from human chromosomes as well as new methods for human and mouse artificial chromosomes.
References
Cell biology
Cytogenetics | Microcell-mediated chromosome transfer | Biology | 445 |
63,707,904 | https://en.wikipedia.org/wiki/Genome%20informatics | Genome Informatics (also genoinformatics or genetic information processing) is a scientific study of information processing in genomes.
Introduction
Information processing and information flow occur in the course of an organism's development and throughout its lifespan. The essence of computation is information processing, and the essence of biological information processing is control of the molecular events inside a cell. Genome informatics introduces computational techniques and applies them to derive information from genome sequences. Genome informatics includes methods to analyze DNA sequence information and to predict protein sequence and structure. Methods of studying a large genomic data include variant-calling, transcriptomic analysis, and variant interpretation. Genome informatics can analyze DNA sequence information and to predict protein sequence and structure. Genome informatics dealing with microbial and metagenomics, sequencing algorithms, variant discovery and genome assembly, evolution, complex traits and phylogenetics, personal and medical genomics, transcriptomics, genome structure and function. Genoinformatics refers to genome and chromosome dynamics, quantitative biology and modeling, molecular and cellular pathologies. Genome informatics also includes the field of genome design. There still a lot more we can do and develop in Genome Informatics. Find a potential disease, searching a solution for a disease, or proving why people get sick for no reason. For genomic informatics there are several main applications for it, including:
genome information analysis
computational modelling of gene regulatory networks
models for complex eukaryotic regulatory DNA sequences
an algorithm for Ab Initio DNA Motif Detection
Applications
Biomolecular systems that can process information are sought for computational applications, because of their potential for parallelism and miniaturization and because their biocompatibility also makes them suitable for future biomedical applications. DNA has been used to design machines, motors, finite automata, logic gates, reaction networks and logic programs, amongst many other structures and dynamic behaviours.
See also
cellular computing
References
Academic disciplines
Bioinformatics
Genetic mapping | Genome informatics | Technology,Engineering,Biology | 390 |
994,834 | https://en.wikipedia.org/wiki/Korean%20numerals | The Korean language has two regularly used sets of numerals: a native Korean system and Sino-Korean system. The native Korean number system is used for general counting, like counting up to 99. It is also used to count people, hours, objects, ages, and more. Sino-Korean numbers on the other hand are used for purposes such as dates, money, minutes, addresses, phone numbers, and numbers above 99.
Construction
For both native and Sino- Korean numerals, the teens (11 through 19) are represented by a combination of tens and the ones places. For instance, 15 would be sib-o (), but not usually il-sib-o in the Sino-Korean system, and yeol-daseot () in native Korean. Twenty through ninety are likewise represented in this place-holding manner in the Sino-Korean system, while Native Korean has its own unique set of words, as can be seen in the chart below. The grouping of large numbers in Korean follows the Chinese tradition of myriads (10000) rather than thousands (1000). The Sino-Korean system is nearly entirely based on the Chinese numerals.
The distinction between the two numeral systems is very important. Everything that can be counted will use one of the two systems, but seldom both. Sino-Korean words are sometimes used to mark ordinal usage: yeol beon () means "ten times" while sip beon () means "number ten."
When denoting the age of a person, one will usually use sal () for the native Korean numerals, and se () for Sino-Korean. For example, seumul-daseot sal () and i-sib-o se () both mean 'twenty-five-year-old'. See also East Asian age reckoning.
The Sino-Korean numerals are used to denote the minute of time. For example, sam-sib-o bun () means "__:35" or "thirty-five minutes."
The native Korean numerals are used for the hours in the 12-hour system and for the hours 0:00 to 12:00 in the 24-hour system. The hours 13:00 to 24:00 in the 24-hour system are denoted using both the native Korean numerals and the Sino-Korean numerals. For example, se si () means '03:00' or '3:00 a.m./p.m.' and sip-chil si () or yeol-ilgop si () means '17:00'.
Some of the native numbers take a different form in front of measure words:
The descriptive forms for 1, 2, 3, 4, and 20 are formed by "dropping the last letter" from the original native cardinal, so to speak. Examples:
han beon ("once")
du gae ("two things")
se si ("three o'clock"), in contrast, in North Korea the Sino-Korean numeral "sam" would normally be used; making it "sam si"
ne myeong ("four people")
seumu mari ("twenty animals")
Something similar also occurs in some Sino-Korean cardinals:
onyuwol ("May and June")
yuwol ("June")
siwol ("October")
The cardinals for three and four have alternative forms in front of some measure words:
seok dal ("three months")
neok jan ("four cups")
Korean has several words formed with two or three consecutive numbers. Some of them have irregular or alternative forms.
한둘 handul ("one or two") / 한두 handu ("one or two" in front of measure words)
두셋 duset ("two or three") / 두세 duse ("two or three" in front of measure words)
서넛 seoneot ("three or four") / 서너 seoneo ("three or four" in front of measure words)
두서넛 duseoneot ("two or three or four") / 두서너 duseoneo ("two or three or four" in front of measure words)
너덧 neodeot, 네댓 nedaet, 네다섯 nedaseot, 너더댓 neodeodaet ("four or five")
대여섯 daeyeoseot, 대엿 daeyeot ("five or six")
예닐곱 yenilgop ("six or seven")
일고여덟 ilgoyeodeol, 일여덟 ilyeodeol ("seven or eight")
여덟아홉 yeodeolahop, 엳아홉 yeotahop ("eight or nine")
As for counting days in native Korean, another set of unique words are used:
하루 haru ("one day")
이틀 iteul ("two days")
사흘 saheul ("three days")
사나흘 sanaheul, 사날 sanal ("three or four days")
나흘 naheul ("four days")
네댓새 nedaessae, 너댓새 neodaessae, 너더댓새 neodeodaessae, 나달 nadal ("four or five days")
닷새 dassae ("five days")
대엿새 daeyeossae ("five or six days")
엿새 yeossae ("six days")
예니레 yenire ("six or seven days")
이레 ire ("seven days")
일여드레 ilyeodeure ("seven or eight days")
여드레 yeodeure ("eight days")
아흐레 aheure ("nine days")
열흘 yeolheul ("ten days")
The native Korean saheul () is often misunderstood as the Sino-Korean sail () due to similar sounds. The two words are different in origin and have different meanings.
Cardinal numerals
Larger numbers
In numbers above 10, elements are combined from largest to smallest, and zeros are implied. Hanja and Hangul numerals are both multiplicative additive rather than positional; to write the number 20 you get the character for two (二/이) and then the character for ten (十/십) to get two tens or twenty (二十/이십).
Pronunciation
The initial consonants of measure words and numbers following the native cardinals ('eight', only when the is not pronounced) and ('ten') become tensed consonants when possible. Thus for example:
(twelve) is pronounced like
(eight (books)) is pronounced like
Several numerals have long vowels, namely (two), (three) and (four), but these become short when combined with other numerals / nouns (such as in twelve, thirteen, fourteen and so on).
The usual liaison and consonant-tensing rules apply, so for example, yesun-yeoseot (sixty-six) is pronounced like (yesun-nyeoseot) and chil-sip (seventy) is pronounced like chil-ssip.
Constant suffixes used in Sino-Korean ordinal numerals
Beon (), ho (), cha (), and hoe () are always used with Sino-Korean or Arabic ordinal numerals. For example, Yihoseon () is Line Number Two in a metropolitan subway system. Samsipchilbeongukdo () is highway number 37. They cannot be used interchangeably.
is 'Apt #906' in a mailing address. 906 without ho () is not used in spoken Korean to imply apartment number or office suite number. The special prefix je () is usually used in combination with suffixes to designate a specific event in sequential things such as the Olympics.
Substitution for disambiguation
In commerce or the financial sector, some Hanja for each Sino-Korean numbers are replaced by alternative ones to prevent ambiguity or retouching.
For verbally communicating number sequences such as phone numbers, ID numbers, etc., especially over the phone, native Korean numbers for 1 and 2 are sometimes substituted for the Sino-Korean numbers. For example, o-o-o hana-dul-hana-dul () instead of o-o-o il-i-il-i () for '555-1212', or sa-o-i-hana () instead of sa-o-i-il () for '4521', because of the potential confusion between the two similar-sounding Sino-Korean numbers.
For the same reason, military transmissions are known to use mixed native Korean and Sino-Korean numerals:
Notes
Note 1: Korean assimilation rules apply as if the underlying form were |sip.ryuk|, giving sim-nyuk instead of the expected sib-yuk.
Note 2: These names are considered archaic, and are not used.
Note 3: The numbers higher than 1020 (hae) are not usually used.
Note 4: The names for these numbers are from Buddhist texts; they are not usually used. Dictionaries sometimes disagree on which numbers the names represent.
References
J.J. Song The Korean language: Structure, Use and Context (2005 Routledge) pp. 81ff.
See also
Korean language
Korean count word
Korean language
Numerals | Korean numerals | Mathematics | 1,997 |
20,293,213 | https://en.wikipedia.org/wiki/The%20Kindness%20Offensive | The Kindness Offensive (TKO) is a group based in London known for orchestrating large-scale random acts of kindness, involving the distribution of industrial quantities of goods to unsuspecting members of the public and charities. The group's stated purpose is to "Practice random kindness and senseless acts of beauty", a phrase first coined by Anne Herbert.
History
The Kindness Offensive was formed in August 2008, when three of the four founding members (David Goodfellow, Benny Crane and James Hunter) asked members of the public in Hampstead what "random acts of kindness" they would like done for them. They received many requests from the public, and the group attempted to meet some of them by contacting companies and persuading them to donate the required goods for free, a technique developed by fourth founding member Robert Williams and referred to by the group as "phone whispering".
TKO attracted press attention in October 2008 for giving away 25 tonnes of non-perishable foods to 14 soup kitchens and drop-in centres across London, England; the event came to be known as "The Mountain of Food". This event was the first of many large-scale events centred on distributing industrial quantities of goods in short periods of time to a wide variety of locations and causes; the most notable of these were The Vinspired Kindness Offensive (2008), The White Stuff Kindness Offensive, which was widely reported as a record-breaking event (2010), The Barclaycard Kindness Offensive (2011), the Hasbro Kindness Offensive (2013), and the Read Free! Kindness Offensive. The large scale 2014 XL Catlin Kindness Offensive event resulted in the events organiser and group co-founder David Goodfellow being awarded with a Points of Light, award by the then UK Prime Minister David Cameron who acknowledged that it generated "a record-breaking Christmas toy donation".
As well as large giveaways, TKO has also staged a series of pop-up events, including The Everyday Kindness Awards in 2009. Over the course of a weekend, actors in public places pretended to need help, and when members of the public stepped up to offer a hand, they received a pop-up celebration rewarding their kindness with champagne, flowers and a gold medal.
The Kindness Offensive established their headquarters in Islington in 2013, which includes a bookshop that offers 100,000's of books free of charge to the public, and a community space whose grounds have been converted into a sensory garden for special needs students. The building has become something of a local landmark due to installations such as a set of giant brockley and a replica TARDIS from the long running UK TV show Doctor Who.
In 2017, Joanna Bevan become the fourth member of The Kindness Offensive to be awarded a place on The Independent Happy List, in recognition of her Kindness Offensive work with special needs children and with providing free language lessons to newcomers to the UK.
See also
Altruism
Cool To Be Kind
Join Me
Kindness
Random act of kindness
Random Acts of Kindness Day
References
External links
Non-profit organisations based in London
Kindness | The Kindness Offensive | Biology | 620 |
42,497,844 | https://en.wikipedia.org/wiki/Xbra | Xbra is a homologue of Brachyury (T) gene for Xenopus. It is a transcription activator involved in vertebrate gastrulation which controls posterior mesoderm patterning and notochord differentiation by activating transcription of genes expressed throughout mesoderm. The effects of Xbra is concentration dependent where concentration gradient controls the development of specific types of mesoderm in Xenopus. Xbra results of the expression of the FGF transcription factor, synthesized by the ventral endoderm. So while ventral mesoderm is characterized by a high concentration of FGF and Xbra, the dorsal mesoderm is characterized by a reunion of two others transcription factors, Siamois and XnR, which activates the synthesis of Goosecoid Transcription Factor. Goosecoid enables the depletion of Xbra. In a nutshell, high concentrations of Xbra induce ventral mesoderm while low concentration stimulates the formation of a back.
Posterior mesoderm development presents two types of cell behaviors, cell migration and convergent extension, in prechordal mesoderm and chordamesoderm cells, respectively. Cell migration is exhibited by the prechordal mesoderm cells, resulting in the formation of the future anterior end. Xbra induces convergent extension which inhibits cell migration and rearranges the chordamesoderm cells into a structure that will later differentiate into notochord. As a result, Xbra acts as a switch to convert between these two behaviors.
Xbra is able to activate itself indirectly, specifically for dorsal mesoderm, through FGF signaling while eFGF maintains Xbra expression, creating an autoregulatory loop.
Inhibition of Xbra leads to abnormal patterning of mesoderm, such as shortened trunk. In a previous study, the activation domain of Xbra was replaced by repressor domain of Drosophila engrailed protein in order to form a dominant-interfering Xbra construct that would help to study the function and regulation of Xbra. The injection of RNA encoding this construct has led to various birth defects such as defective blastopore closure and abnormal notochord differentiation in the developing embryo.
References
Transcription factors
Xenopus | Xbra | Chemistry,Biology | 467 |
39,413,828 | https://en.wikipedia.org/wiki/Gabriola%20%28typeface%29 | Gabriola is a display typeface designed by John Hudson for Microsoft Corporation. It is named after Gabriola Island, British Columbia, Canada. Versions of Gabriola were supplied with Microsoft Windows since Version 7, and with some Microsoft Office applications since Version 2010.
Design
Gabriola was inspired by the calligraphy of Jan van de Velde the Elder. It was developed with advanced OpenType features and has been optimized for ClearType rendering to improve legibility on screens. Hudson added a number of stylistic alternate characters and flourishes, which were grouped thematically by stylistic set into different styles of calligraphy.
Distinguishing features
Easily identifiable and unusual features include:
The flourish of the uppercase Q extends far below the following letter; e.g. Qualifier
The flourish of the lowercase f and both the lowercase j and uppercase J extends far below the previous letter; e.g. alforja
References
External links
The Importance of Gabriola by Larry Larsen
Microsoft typefaces
Typefaces and fonts introduced in 2008
Typefaces designed by John Hudson
Script typefaces | Gabriola (typeface) | Technology | 222 |
45,404,358 | https://en.wikipedia.org/wiki/Carbanak | Carbanak is an APT-style campaign targeting (but not limited to) financial institutions, that was discovered in 2014 by the Russian cyber security company Kaspersky Lab. It utilizes malware that is introduced into systems running Microsoft Windows using phishing emails, which is then used to steal money from banks via macros in documents. The hacker group is said to have stolen over 900 million dollars from the banks as well as money from over a thousand private customers.
The criminals were able to manipulate their access to the respective banking networks in order to steal the money in a variety of ways. In some instances, ATMs were instructed to dispense cash without having to locally interact with the terminal. Money mules, which were hired through the Moldavian mafia, would collect the money and transfer it over the SWIFT network to the criminals’ accounts, Kaspersky said. The Carbanak group went so far as to alter databases and pump up balances on existing accounts and pocketing the difference unbeknownst to the user whose original balance is still intact.
Their intended targets were primarily in Russia, followed by the United States, Germany, China and Ukraine, according to Kaspersky Lab. One bank lost $7.3 million when its ATMs were programmed to spew cash at certain times that henchmen would then collect, while a separate firm had $10 million taken via its online platform.
Kaspersky Lab is helping to assist in investigations and countermeasures that disrupt malware operations and cybercriminal activity. During the investigations they provide technical expertise such as analyzing infection vectors, malicious programs, supported command and control infrastructure and exploitation methods.
FireEye published research tracking further activities, referring to the group as FIN7, including an SEC-themed spear phishing campaign. Proofpoint also published research linking the group to the Bateleur backdoor, and expanded the list of targets to U.S.-based chain restaurants, hospitality organizations, retailers, merchant services, suppliers and others beyond their initial financial services focus.
On 26 October 2020, PRODAFT (Switzerland) started publishing internal details of the Fin7/Carbanak group and tools they use during their operation. Published information is claimed to be originated from a single OPSEC failure on the threat actor's side.
On March 26, 2018, Europol claimed to have arrested the "mastermind" of the Carbanak and associated Cobalt or Cobalt Strike group in Alicante, Spain, in an investigation led by the Spanish National Police with the cooperation of law enforcement in multiple countries as well as private cybersecurity companies. The group's campaigns appear to have continued, however, with the Hudson's Bay Company breach using point of sale malware in 2018 being attributed to the group.
Controversy
Some controversy exists around the Carbanak attacks, as they were seemingly described several months earlier in a report by the Internet security companies Group-IB (Singapore) and Fox-IT (The Netherlands) that dubbed the attack Anunak. The Anunak report shows also a greatly reduced amount of financial losses and according to a statement issued by Fox-IT after the release of The New York Times article, the compromise of banks outside Russia did not match their research. Also in an interview conducted by Russian newspaper Kommersant the controversy between the claims of Kaspersky Lab and Group-IB come to light where Group-IB claims no banks outside of Russia and Ukraine were hit, and the activity outside of that region was focused on Point of Sale systems.
Reuters issued a statement referencing a Private Industry Notification issued by the FBI and USSS (United States Secret Service) claiming they have not received any reports that Carbanak has affected the financial sector. Two representative groups of the US banking industry FS-ISAC and ABA (American Bankers Association) in an interview with Bank Technology News say no US banks have been affected.
References
Malware
Hacking in the 2010s
2014 in computing
Cyberattacks on banking industry
Criminal advanced persistent threat groups | Carbanak | Technology | 814 |
23,877,073 | https://en.wikipedia.org/wiki/Azure%20A | Azure A is an organic compound with the chemical formula C14H14ClN3S. It is a light blue to dark blue dye. It is used as a screening test for mucopolysaccharides. It can also be used to stain lysosomes in blood smears, and is often used in Giemsa stain.
Thiazine dyes
Chlorides
Phenothiazines | Azure A | Chemistry | 86 |
7,914,639 | https://en.wikipedia.org/wiki/Analyte-specific%20reagent | Analyte-specific reagents (ASRs) are a class of biological molecules which can be used to identify and measure the amount of an individual chemical substance in biological specimens.
Regulatory definition
The U.S. Food and Drug Administration (FDA) defines analyte specific reagents (ASRs) in 21 CFR 864.4020 as “antibodies, both polyclonal and monoclonal, specific receptor proteins, ligands, nucleic acid sequences, and similar reagents which, through specific binding or chemical reaction with substances in a specimen, are intended to be used in a diagnostic application for identification and quantification of an individual chemical substance or ligand in biological specimens.”
In simple terms, an analyte specific reagent is the active ingredient of an in-house test.
External links
Guidance for Industry and FDA Staff - Commercially Distributed Analyte Specific Reagents (ASRs): Frequently Asked Questions
Code of Federal Regulations - Specimen Preparation Reagents (21CFR864.4020)
Chemical tests
Biomolecules | Analyte-specific reagent | Chemistry,Biology | 217 |
76,773,719 | https://en.wikipedia.org/wiki/NGC%203758 | NGC 3758 known as the Owl Galaxy, is a type Sb spiral galaxy in the constellation of Leo. It is located 447 million light-years from the Solar System and an approximate diameter of 70,000 light-years. NGC 3758 was discovered by Ralph Copeland on March 18, 1874, but also independently discovered by Edouard Stephan ten years later.
Description
NGC 3758 is classified as a Seyfert 1 type galaxy. It is classified a Markarian galaxy (designated Mrk 739), because compared to other galaxies its nucleus emits excessive amounts of ultraviolet rays. It is a binary active galactic nucleus galaxy, a rare example of a galaxy merger.
NGC 3758 is made up of two separate galaxies, NGC 3758W and NGC 3758E. Each of the two galaxies has a supermassive black hole, which is only 11,000 light-years apart and gorging on infalling gas. Both black holes are active, in which large amounts of gas is sent spiraling inward, which it becomes hot and radiates energy. The galaxies are gravitationally bound together and such, their orbits will dynamically decay until their nuclei merge in which the process takes a few billion years.
The galaxy has an appearance of a friendly-looking object complete with two cores as the eyes and a swirling grin. It is possible that binary black holes on the verge of merging in NGC 3758 can turn stars into hypervelocity stars and catapult them out of their host galaxy.
NGC 3758 contains an extended emission-line region (EELR), which was discovered in the Galaxy Zoo project. This EELR could originate from both AGN or from just one. Detailed oxygen [O III] imaging could reveal which AGN is responsible for this EELR. ESO's VLT MUSE instrument is capable of such observations and MUSE did observe NGC 3758 in 2016, but no publication about the MUSE data concerning the EELR exists as of May 2024.
References
3758
Leo (constellation)
0739
Spiral galaxies
Astronomical objects discovered in 1874
Discoveries by Ralph Copeland
Seyfert galaxies
Supermassive black holes
035905
035905 | NGC 3758 | Physics,Astronomy | 443 |
61,717,864 | https://en.wikipedia.org/wiki/Joyce%20Waters | Joyce Mary Waters, Lady Waters (née Partridge; born 2 June 1931) is a New Zealand inorganic chemist and X-ray crystallographer, who is currently professor emeritus at Massey University. She was the second woman to receive a PhD in chemistry at the University of Auckland, and the first woman to serve as president of the New Zealand Institute of Chemistry.
Early life and family
Waters was born Joyce Mary Partridge in Auckland on 2 June 1931, the daughter of Mary Elizabeth Partridge (née Harrison) and Thomas Harold Charles Partridge. She was educated at Diocesan School for Girls, Auckland, from 1938 to 1949, and went on to study at Auckland University College, graduating Bachelor of Science in 1954, Master of Science with first-class honours in 1955, and PhD in 1960. The title of her doctoral thesis, supervised by John Llewellyn and David Hall, was A study of some co-ordination compounds formed between nickel diammines and the nitrite ion. She was the second woman to complete a PhD in chemistry at Auckland.
In 1959, she married fellow inorganic chemist Neil Waters, who was knighted in 1995.
Academic career
Waters was appointed as a lecturer in chemistry at the University of Auckland in 1961, rising to the rank of associate professor. In 1983, she joined Massey University as a senior research fellow and associate professor in chemistry, and in 2000 she was made a full professor at Massey's Albany campus. Following her retirement, she was conferred with the title of professor emeritus.
Her research focused on the determination of molecular structure using X-ray crystallography. An early publication by Waters was the first to describe the structure of a coordination complex containing a metal–hydrogen bond.
Waters served as president of the New Zealand Institute of Chemistry in 1989–1990, and was the first woman to hold the position.
Later life
Following her formal retirement, Waters continued part-time research and teaching activities at Massey Albany. Her husband, Neil Waters, died in Auckland in 2018.
Honours and awards
In 1996, Waters was awarded the Massey Medal of Massey University, in recognition of services to the university and to science. In the 2006 New Year Honours, she was appointed an Officer of the New Zealand Order of Merit, for services to chemistry.
Waters was elected a Fellow of the Royal Society of New Zealand in 1999, and is also a Fellow of the New Zealand Institute of Chemistry.
References
1931 births
Living people
People from Auckland
People educated at Diocesan School for Girls, Auckland
University of Auckland alumni
New Zealand chemists
New Zealand women chemists
Inorganic chemists
Crystallographers
New Zealand women academics
Academic staff of the University of Auckland
Academic staff of Massey University
Fellows of the Royal Society of New Zealand
Officers of the New Zealand Order of Merit
Fellows of the New Zealand Institute of Chemistry | Joyce Waters | Chemistry,Materials_science | 556 |
16,364,229 | https://en.wikipedia.org/wiki/Arakelov%20theory | In mathematics, Arakelov theory (or Arakelov geometry) is an approach to Diophantine geometry, named for Suren Arakelov. It is used to study Diophantine equations in higher dimensions.
Background
The main motivation behind Arakelov geometry is that there is a correspondence between prime ideals and finite places , but there also exists a place at infinity , given by the Archimedean valuation, which doesn't have a corresponding prime ideal. Arakelov geometry gives a technique for compactifying into a complete space which has a prime lying at infinity. Arakelov's original construction studies one such theory, where a definition of divisors is constructor for a scheme of relative dimension 1 over such that it extends to a Riemann surface for every valuation at infinity. In addition, he equips these Riemann surfaces with Hermitian metrics on holomorphic vector bundles over X(C), the complex points of . This extra Hermitian structure is applied as a substitute for the failure of the scheme Spec(Z) to be a complete variety.
Note that other techniques exist for constructing a complete space extending , which is the basis of F1 geometry.
Original definition of divisors
Let be a field, its ring of integers, and a genus curve over with a non-singular model , called an arithmetic surface. Also, let be an inclusion of fields (which is supposed to represent a place at infinity). Also, let be the associated Riemann surface from the base change to . Using this data, one can define a c-divisor as a formal linear combination where is an irreducible closed subset of of codimension 1, , and , and the sum represents the sum over every real embedding of and over one embedding for each pair of complex embeddings . The set of c-divisors forms a group .
Results
defined an intersection theory on the arithmetic surfaces attached to smooth projective curves over number fields, with the aim of proving certain results, known in the case of function fields,
in the case of number fields. extended Arakelov's work by establishing results such as a Riemann-Roch theorem, a Noether formula, a Hodge index theorem and the nonnegativity of the self-intersection of the dualizing sheaf in this context.
Arakelov theory was used by Paul Vojta (1991) to give a new proof of the Mordell conjecture, and by in his proof of Serge Lang's generalization of the Mordell conjecture.
developed a more general framework to define the intersection pairing defined on an arithmetic surface over the spectrum of a ring of integers by Arakelov. developed a theory of positive line bundles and proved a Nakai–Moishezon type theorem for arithmetic surfaces. Further developments in the theory of positive line bundles by and culminated in a proof of the Bogomolov conjecture by and .
Arakelov's theory was generalized by Henri Gillet and Christophe Soulé to higher dimensions. That is, Gillet and Soulé defined an intersection pairing on an arithmetic variety. One of the main results of Gillet and Soulé is the arithmetic Riemann–Roch theorem of , an extension of the Grothendieck–Riemann–Roch theorem to arithmetic varieties.
For this one defines arithmetic Chow groups CHp(X) of an arithmetic variety X, and defines Chern classes for Hermitian vector bundles over X taking values in the arithmetic Chow groups.
The arithmetic Riemann–Roch theorem then describes how the Chern class behaves under pushforward of vector bundles under a proper map of arithmetic varieties. A complete proof of this theorem was only published recently by Gillet, Rössler and Soulé.
Arakelov's intersection theory for arithmetic surfaces was developed further by . The theory of Bost is based on the use of Green functions which, up to logarithmic singularities, belong to the Sobolev space . In this context, Bost obtains an arithmetic Hodge index theorem and uses this to obtain Lefschetz theorems for arithmetic surfaces.
Arithmetic Chow groups
An arithmetic cycle of codimension p is a pair (Z, g) where Z ∈ Zp(X) is a p-cycle on X and g is a Green current for Z, a higher-dimensional generalization of a Green function. The arithmetic Chow group of codimension p is the quotient of this group by the subgroup generated by certain "trivial" cycles.
The arithmetic Riemann–Roch theorem
The usual Grothendieck–Riemann–Roch theorem describes how the Chern character ch behaves under pushforward of sheaves, and states that ch(f*(E))= f*(ch(E)TdX/Y), where f is a proper morphism from X to Y and E is a vector bundle over f. The arithmetic Riemann–Roch theorem is similar, except that the Todd class gets multiplied by a certain power series.
The arithmetic Riemann–Roch theorem states
where
X and Y are regular projective arithmetic schemes.
f is a smooth proper map from X to Y
E is an arithmetic vector bundle over X.
is the arithmetic Chern character.
TX/Y is the relative tangent bundle
is the arithmetic Todd class
is
R(X) is the additive characteristic class associated to the formal power series
See also
Hodge–Arakelov theory
Hodge theory
P-adic Hodge theory
Adelic group
Notes
References
.
.
.
.
.
.
.
External links
Original paper
Arakelov geometry preprint archive
Algebraic geometry
Diophantine geometry | Arakelov theory | Mathematics | 1,160 |
11,063,337 | https://en.wikipedia.org/wiki/Botryosphaeria%20dothidea | Botryosphaeria dothidea is a plant pathogen that causes the formation of cankers on a wide variety of tree and shrub species. It has been reported on several hundred plant hosts and on all continents except Antarctica. B. dothidea was redefined in 2004, and some reports of its host range from prior to that time likely include species that have since been placed in another genus. Even so, B. dothidea has since been identified on a number of woody plants—including grape, mango, olive, eucalyptus, maple, and oak, among others—and is still expected to have a broad geographical distribution. While it is best known as a pathogen, the species has also been identified as an endophyte, existing in association with plant tissues on which disease symptoms were not observed. It can colonize some fruits, in addition to woody tissues.
Life as a plant pathogen – "Bot rot" of apple
White rot, or "Bot rot", of apple is one of the many plant diseases that have been attributed to B. dothidea. Recent analysis has confirmed the presence of B. dothidea, along with other Botryosphaeria species, on Malus sp.. Cankers and other dead wood and bark tissue, as well as mummified fruit (fruit infected by the pathogen and remaining in the orchard) serve as sources of primary and secondary inoculum.
Both pycnidia and pseudothecia are observed on plant tissues, producing conidia and ascospores. Conidia are produced in greater numbers. Using spore traps for airborne spores and funnel traps for rainwater, Sutton (1981) determined that, while both conidia and ascospores of B. dothidea are released from infected pruning waste (dead wood) during rainfall events and conidia are predominantly water-dispersed, ascospores spread in both air and water. Conidia and ascospores germinate most readily at . (B. dothidea has been reported to grow best, in culture, at .) Lenticels and wounds provide locations for wood infection
The cankers of white rot appear similar to those of black rot, caused by Diplodia seriata (formerly B. obtusa). Girdling of limbs by cankers can result in yellowing ("chlorosis") of leaves on affected branches in the spring. While the precise time of fruit infection is unclear, symptoms of fruit rot appear approximately four to six weeks before harvest. The name "white rot" comes from the light brown color of the surface of affected red-skinned apples.
Classification and characteristics
Botryosphaeria dothidea is the type species of the genus Botryosphaeria. While the International Botanical Congress recently emended the International Code of Nomenclature for algae, fungi, and plants to state that one fungal species should be called by one name, the sexual (teleomorphic) and asexual (anamorphic) stages of single fungal species have often been called by different names. B. dothidea was the name given to the teleomorphic form, and Fusicoccum aesculi has been identified the anamorph of B. dothidea, as currently defined. Phillips et al. (2013) chose to use the genus name Botryosphaeria, rather than Fusicoccum, since Botryosphaeria is commonly used and is the type genus of the family Botryosphaeriaceae.
Fries first published a description of B. dothidea as Sphaeria dothidea in Systema Mycologicum in 1823. Cesati and De Notaris described the genus Botryosphaeria and moved the species formerly known as S. dothidea into the new genus.
After determining that a type specimen consistent with the original description of Sphaeria dothidea, on ash, did not exist, Slippers et al. (2004) designated an epitype specimen to go along with a non-sporulating neotype from the collection of Fries, who published the original description of the species. Slippers et al. (2004) then revised the description of B. dothidea. The name is believed to have previously encompassed a species complex, and references to it in older literature might represent species now otherwise identified.
Like other members of the Dothideomycetes, the sexual stage of B. dothidea has bitunicate asci, which are borne in cavities ("ascomata") formed through a process known as "ascolocular development". In the case of B. dothidea, these ascomata are pseudothecia. The asci in the pseudothecia produce ascospores that can then infect plants. Like other species in the order Botryosphaeriales, B. dothidea ascomata have "multilayered dark brown walls" and contain septate pseudoparaphyses which are transparent or translucent (hyaline). Pseudothecia are sometimes located alone and other times clustered together.
In the asexual stage, conidia, which can also infect plants, are produced in pycnidia. The pycnidia and pseudothecia of B. dothidea look very similar. Microconidia have also been reported in at least one B. dothidea isolate. Microconidia are small, asexual spores that often act as male gametes or gametangia (spermatia) in a process of cytoplasmic fusion (plasmogamy)
According to a key provided in Phillips et al. (2013), B. dothidea can be distinguished from six other members of the genus by conidia that are typically longer than 20 μm, have a length to width ratio greater than 4.5, and occur on hosts other than Vaccinium species. These conidia are "narrowly...or irregularly fusiform," have thin walls, and are generally transparent or translucent (hyaline) and aseptate but sometimes form up to two septa and/or darken when they are older. Differentiating between species based on morphology depends on observing multiple samples, to get an idea of prevailing character states, and doing so at the appropriate developmental stage. Sequencing is considered an important companion to morphological identification
References
External links
Index Fungorum
MycoBank
USDA ARS Fungal Databases
Fungal plant pathogens and diseases
Grapevine trunk diseases
Fungi described in 1823
dothidea
Fungus species | Botryosphaeria dothidea | Biology | 1,344 |
24,029,359 | https://en.wikipedia.org/wiki/C21H29NO2 | {{DISPLAYTITLE:C21H29NO2}}
The molecular formula C21H29NO2 (molar mass: 327.46 g/mol, exact mass: 327.219829 u) may refer to:
Butorphanol, an opioid analgesic
Norelgestromin, a progestin medication
Molecular formulas | C21H29NO2 | Physics,Chemistry | 78 |
40,201,915 | https://en.wikipedia.org/wiki/Outlast | Outlast is a 2013 first-person psychological survival horror video game developed and published by Red Barrels. It revolves around freelance investigative journalist Miles Upshur, who decides to investigate Mount Massive Asylum, a remote psychiatric hospital, located deep in the mountains of Lake County, Colorado.
The game was released for Microsoft Windows on September 4, 2013, PlayStation 4 on February 4, 2014, and Xbox One on June 19, 2014. Linux and OS X versions were released on March 31, 2015 while a Nintendo Switch version was released on February 27, 2018. Outlast received critical acclaim for its atmosphere, horror elements, and overall gameplay. As of October 2024, the game has a playerbase of 37 million.
A sequel, Outlast 2, was released on April 25, 2017, while a prequel, The Outlast Trials, was released on March 5, 2024. The Murkoff Account, a comic book series set between Outlast and Outlast 2, was released from July 2016 to November 2017. A film adaptation is also in development.
Gameplay
In Outlast, the player assumes the role of freelance investigative journalist Miles Upshur, as he navigates in Mount Massive Asylum, a dilapidated psychiatric hospital in the mountains of Lake County, Colorado, that is overrun by homicidal patients. The game is played from a first-person perspective and features some stealth gameplay mechanics. The player can walk, run, crouch, jump, climb ladders and vault over objects. Unlike most games, however, the player does not have a visible health bar on the screen and is unable to attack enemies. The player must instead rely on stealth tactics such as hiding in lockers, sneaking past enemies, staying in the shadows, and hiding behind or under things to survive. Alternatively, the player can attempt to outrun their pursuer. If the player dies, the game will reset to the most recent checkpoint.
Most of the hospital is unlit, and the only way for the player to see while in the dark is through the lens of a camcorder equipped with night vision. Using the night vision mode will slowly consume batteries, of which there are not many, forcing the player to scavenge for additional batteries found throughout the hospital. Outlast makes heavy use of traditional jump scares and audio cues, which alert the player if an enemy has seen them. If the player records specific events with their camcorder, Miles will write a note about it, providing further insight into his thoughts. Documents can be collected, which offer backstory and other expository information about the facility, including pages taken from patients' diaries and reports from the hospital's staff.
Developer Red Barrels have pointed to the survival-focused gameplay in Amnesia: The Dark Descent (2010) as a primary influence on the combat-free narrative style of Outlast. Found footage horror films like Quarantine (2008) and Rec (2007) also served as influences.
Plot
Freelance investigative journalist Miles Upshur receives an anonymous e-mail about inhumane experiments at Mount Massive Asylum, a remote psychiatric hospital owned by the notoriously unethical Murkoff Corporation. Upon entering, Miles is shocked to discover its halls ransacked and littered with the staff's mutilated corpses. He is informed by a dying officer of Murkoff's private military unit that the hospital's deranged inmates, known as "variants", have escaped and are freely roaming the grounds. The officer implores Miles to escape and reveals that the main entrance can be unlocked from the hospital's security control room.
As Miles moves on, he is suddenly ambushed by hulking variant Chris Walker, who knocks him unconscious. While incapacitated, Miles meets Father Martin Archimbaud, a self-appointed priest with schizotypal personality disorder, who claims that Miles is his "apostle" and sabotages his escape by cutting off power to the entrance. Miles restores power in the control room, but Father Martin injects him with an anesthetic. He also shows Miles footage of the "Walrider", a ghost-like entity that kills patients and staff alike, which he claims is responsible for the hospital's dilapidated state.
Regaining consciousness, Miles finds himself trapped in a decaying cell block filled with catatonic and demented patients. He escapes through the sewers to the main wards, pursued by Walker and two cannibalistic twins, only to be captured by Richard Trager, a former Murkoff executive driven insane. Trager amputates two of Miles' fingers and prepares to do the same to his tongue and genitals. However, Miles escapes to an elevator, inadvertently crushing Trager to death between floors when he attacks him. Miles then reconvenes with Father Martin, who tells him to go to the hospital's chapel.
Miles reaches an auditorium and learns that the Walrider was created by Rudolf Wernicke, a German scientist brought to the United States during Operation Paperclip. Wernicke believed that intensive dream therapy conducted on traumatized patients could connect swarms of nanites into a single malevolent being. Miles also learns that the experiments were originally part of the MKUltra program. In the chapel, Miles finds a crucified Father Martin, who gives him a key to the lobby elevator that he insists will take him to freedom before immolating himself. Miles takes the elevator, which descends into a subterranean laboratory.
Walker arrives and attacks Miles, only to be eviscerated by the Walrider. Miles locates an aged Wernicke, who confirms that the Walrider is a biotechnological nanite entity controlled by Billy Hope, a comatose patient of Murkoff's experiments. Wernicke orders Miles to terminate Billy's life support in the hopes that it will destroy the Walrider. Miles acomplishes the task; however, just before Billy dies, the Walrider attacks Miles and possesses his body. On his way out of the laboratory, a heavily injured Miles encounters a Murkoff private military unit led by Wernicke, which guns him down.
While a horrified Wernicke realizes that Miles has become the Walrider's new host, panicked screams, gunfire, and mauling sounds are heard as the screen fades to black.
Outlast: Whistleblower
A downloadable content, Outlast: Whistleblower, was released for Microsoft Windows on May 6, 2014, PlayStation 4 on May 6, 2014, and Xbox One on June 18, 2014. Linux and OS X versions were released on March 31, 2015. It serves as an overlapping prequel to the original game, showing the events both before and after the main plotline, and follows Waylon Park, the anonymous tipster to Miles Upshur.
Plot
Software engineer Waylon Park works at Mount Massive Asylum, entailing maintenance to the "Morphogenic Engine", which allows Murkoff scientists to manipulate lucid dreams in the hospital's comatose patients. After witnessing the engine's effects on the abused patients, a horrified Waylon sends an anonymous e-mail to Miles Upshur to expose Murkoff's inhumane experiments. Shortly after, Waylon is summoned to the laboratory's operations center to debug a monitoring system.
When Waylon returns to his office, his supervisor Jeremy Blaire has him detained and exposed to the engine after discovering his e-mail. However, Waylon escapes his restraints when the Walrider is unleashed. He roams the increasingly decrepit facility as surviving guards and medical personnel flee from the newly freed variants, searching for a shortwave radio that he can use to contact the authorities, all the while eluding cannibal variant Frank Manera, who wields an electric bone saw. Just as Waylon manages to find a working radio transmitter, Blaire destroys it and tries to suffocate Waylon, but is forced to flee by an approaching Chris Walker.
Waylon finds his way into the hospital's vocational block, where he is captured by Eddie Gluskin, a serial killer obsessed with finding the "perfect bride" by killing other patients and mutilating their genitalia. Gluskin tries to hang Waylon in the hospital's gymnasium with his other victims, but during the struggle, he is entangled by his pulley system and a sudden weight shift causes him to be fatally impaled on a loose section of rebar. As dawn breaks, Murkoff's private military unit arrives at the hospital, intent on eliminating all the variants. Waylon slips past them and escapes into the lobby, where he finds a gravely wounded Blaire.
Blaire suddenly stabs Waylon and insists that no one can know the truth about the hospital before the Walrider kills him. Waylon then stumbles out the open main entrance and towards Miles' jeep, which is still parked near the entrance. He drives away as Miles, now possessed by the Walrider, also emerges from the hospital. In the epilogue, Waylon is sitting at a laptop with his camcorder footage, ready for upload to expose the hospital's experiments. An associate informs him that it will be more than enough to ruin Murkoff, but is warned that they will seek to retaliate against him and his family. Despite some initial hesitation, Waylon uploads the footage.
Development
Outlast was Red Barrels' first game, although the team had worked on big AAA games in Ubisoft prior like Prince of Persia, Assassin’s Creed, and Splinter Cell. The game was made in 14 months with a team of 10 people. Red Barrels' CEO Philippe Morin said in 2018 that they initially could not find anyone to invest in the project for 18 months, which means 18 months without salary. Fortunately, they were able to get the funding from Canada Media Fund for $1.36 million CAD.
Release
Outlast was released on September 4, 2013, for download through Steam, and it was released on February 4, 2014, for the PlayStation 4 as the free monthly title for PlayStation Plus users. In December 2017, Red Barrels announced that Outlast, including the Whistleblower DLC and Outlast 2, would be coming to the Nintendo Switch in early 2018. The title was released by surprise on February 27, 2018, under the title Outlast: Bundle of Terror via Nintendo eShop.
Reception
Outlast received generally positive reviews from critics. Aggregating review website Metacritic gave the Xbox One version 80/100 based on 6 reviews, the Microsoft Windows version 80/100 based on 59 reviews, and the PlayStation 4 version 78/100 based on 33 reviews. It has been received with numerous accolades and awards from E3 2013, including the "Most Likely to Make you Faint" honor, and one of "Best of E3".
The PC gaming website Rock, Paper, Shotgun gave Outlast a very positive review, noting that "Outlast is not an experiment in how games can be scary, it’s an exemplification." Marty Sliva of IGN rated the game with a score of 7.8, praising the horror elements and gameplay while criticizing the environments and character modeling.
GameSpot gave the game a positive review as well stating that "Outlast isn't really a game of skill, and as it turns out, that makes sense. You're not a cop or a soldier or a genetically enhanced superhero. You're just a reporter. And as a reporter, you don't possess many skills with which you can fend off the hulking brutes, knife-wielding stalkers, and other homicidal maniacs who lurk in the halls of the dilapidated Mount Massive Asylum. You can't shoot them, or punch them, or rip pipes from the walls to clobber them with. You can only run and hide".
Sequels
On October 23, 2014, Red Barrels revealed that due to the success of Outlast, a sequel was in development. It was initially intended to be released in late 2016, but was delayed to early 2017 due to complications during development. Subsequently, the release date was further pushed to Q2 2017, despite the intended Q1 2017 release. On March 6, 2017, Red Barrels announced that a physical bundle, Outlast Trinity, would be released for Xbox One and PlayStation 4 on April 25.
The sequel, titled Outlast 2, was made digitally available for Microsoft Windows, PlayStation 4, and Xbox One on April 25, 2017; and came to the Nintendo Switch, alongside Outlast, in February 2018. It takes place in the same universe as the first game, but features a new storyline with different characters, set in the Arizona desert.
Outlast 3 was announced in December 2017, though no time frame or target platforms were confirmed. During this announcement, Red Barrels said that because they could not easily add downloadable content for Outlast 2, they had a smaller separate project related to Outlast that would be released before Outlast 3. The project, teased in October 2019, is a prequel for both Outlast games, called The Outlast Trials, and is set in the Cold War. The game was released on May 18, 2023 via early access for Microsoft Windows, and for a full launch on March 5, 2024 on Windows, PlayStation 4, Xbox One, Xbox Series X/S, and PlayStation 5.
Film adaptation
On October 30, 2024, it was announced that a film adaptation was in development at Lionsgate, with Roy Lee producing and J. T. Petty, who wrote the original game, penning the screenplay.
References
External links
2013 video games
2010s horror video games
Linux games
MacOS games
Video games about mental health
Video games about amputees
Nanopunk
Nintendo Switch games
PlayStation 4 games
PlayStation Network games
Works about Project MKUltra
Psychological thriller video games
Psychological horror games
Splatterpunk
Survival horror video games
Works about whistleblowing
Red Barrels games
Single-player video games
Indie games
Unreal Engine 3 games
Video games adapted into comics
Video games developed in Canada
Video games set in 2013
Video games set in Colorado
Video games set in psychiatric hospitals
Video games set in the United States
Windows games
Xbox One games
Fiction about nanotechnology
Human experimentation in fiction
Rape in video games
Walking simulators | Outlast | Materials_science | 2,952 |
43,490,332 | https://en.wikipedia.org/wiki/Genetic%20resources | Genetic resources are genetic material of actual or potential value, where genetic material means any material of plant, animal, microbial or other origin containing functional units of heredity.
Genetic resources is one of the three levels of biodiversity defined by the Convention on Biological Diversity in Rio, 1992.
Examples
Animal genetic resources for food and agriculture
Forest genetic resources
Germplasm, genetic resources that are preserved for various purposes such as breeding, preservation, and research
Plant genetic resources
Genetic resources conservation and sustainable use
See also
Cryoconservation of animal genetic resources, a strategy to preserve genetic resources cryogenically
Commission on Genetic Resources for Food and Agriculture, the only permanent intergovernmental body that addresses biological diversity for food and agriculture
International Treaty on Plant Genetic Resources for Food and Agriculture, an international agreement to promote sustainable use of the world's plant genetic resources
Gene bank, a type of biorepository which preserves genetic material
Genetic diversity
The State of the World's Animal Genetic Resources for Food and Agriculture
References
Genetics
Biodiversity | Genetic resources | Biology | 206 |
3,224,769 | https://en.wikipedia.org/wiki/Computer%20network%20programming | Computer network programming involves writing computer programs that enable processes to communicate with each other across a computer network.
Connection-oriented and connectionless communications
Very generally, most of communications can be divided into connection-oriented, and connectionless. Whether a communication is connection-oriented or connectionless, is defined by the communication protocol, and not by . Examples of the connection-oriented protocols include and , and examples of connectionless protocols include , "raw IP", and .
Clients and servers
For connection-oriented communications, communication parties usually have different roles. One party is usually waiting for incoming connections; this party is usually referred to as "server". Another party is the one which initiates connection; this party is usually referred to as "client".
For connectionless communications, one party ("server") is usually waiting for an incoming packet, and another party ("client") is usually understood as the one which sends an unsolicited packet to "server".
Popular protocols and APIs
Network programming traditionally covers different layers of OSI/ISO model (most of application-level programming belongs to L4 and up). The table below contains some examples of popular protocols belonging to different OSI/ISO layers, and popular APIs for them.
See also
Software-defined networking
Infrastructure as code
Site reliability engineering
DevOps
References
W. Richard Stevens: UNIX Network Programming, Volume 1, Second Edition: Networking APIs: Sockets and XTI, Prentice Hall, 1998,
Computer networks engineering
Computer programming
Inter-process communication | Computer network programming | Technology,Engineering | 308 |
10,090,547 | https://en.wikipedia.org/wiki/Peano%20existence%20theorem | In mathematics, specifically in the study of ordinary differential equations, the Peano existence theorem, Peano theorem or Cauchy–Peano theorem, named after Giuseppe Peano and Augustin-Louis Cauchy, is a fundamental theorem which guarantees the existence of solutions to certain initial value problems.
History
Peano first published the theorem in 1886 with an incorrect proof. In 1890 he published a new correct proof using successive approximations.
Theorem
Let be an open subset of with
a continuous function and
a continuous, explicit first-order differential equation defined on D, then every initial value problem
for f with
has a local solution
where is a neighbourhood of in ,
such that for all .
The solution need not be unique: one and the same initial value may give rise to many different solutions .
Proof
By replacing with , with , we may assume . As is open there is a rectangle .
Because is compact and is continuous, we have and by the Stone–Weierstrass theorem there exists a sequence of Lipschitz functions converging uniformly to in . Without loss of generality, we assume for all .
We define Picard iterations as follows, where . , and . They are well-defined by induction: as
is within the domain of .
We have
where is the Lipschitz constant of . Thus for maximal difference , we have a bound , and
By induction, this implies the bound which tends to zero as for all .
The functions are equicontinuous as for we have
so by the Arzelà–Ascoli theorem they are relatively compact. In particular, for each there is a subsequence
converging uniformly to a continuous function . Taking limit
in
we conclude that . The functions are in the closure of a relatively compact set, so they are themselves relatively compact. Thus there is a subsequence converging uniformly to a continuous function . Taking limit in we conclude that , using the fact that are equicontinuous by the Arzelà–Ascoli theorem. By the fundamental theorem of calculus, in .
Related theorems
The Peano theorem can be compared with another existence result in the same context, the Picard–Lindelöf theorem. The Picard–Lindelöf theorem both assumes more and concludes more. It requires Lipschitz continuity, while the Peano theorem requires only continuity; but it proves both existence and uniqueness where the Peano theorem proves only the existence of solutions. To illustrate, consider the ordinary differential equation
on the domain
According to the Peano theorem, this equation has solutions, but the Picard–Lindelöf theorem does not apply since the right hand side is not Lipschitz continuous in any neighbourhood containing 0. Thus we can conclude existence but not uniqueness. It turns out that this ordinary differential equation has two kinds of solutions when starting at , either or . The transition between and can happen at any .
The Carathéodory existence theorem is a generalization of the Peano existence theorem with weaker conditions than continuity.
The Peano existence theorem cannot be straightforwardly extended to a general Hilbert space : for an open subset of , the continuity of alone is insufficient for guaranteeing the existence of solutions for the associated initial value problem.
Notes
References
Augustin-Louis Cauchy
Theorems in analysis
Ordinary differential equations | Peano existence theorem | Mathematics | 671 |
3,584,951 | https://en.wikipedia.org/wiki/Orthotropic%20deck | An orthotropic bridge or orthotropic deck is typically one whose fabricated deck consists of a structural steel deck plate stiffened either longitudinally with ribs or transversely, or in both directions. This allows the fabricated deck both to directly bear vehicular loads and to contribute to the bridge structure's overall load-bearing behaviour. The orthotropic deck may be integral with or supported on a grid of deck framing members, such as transverse floor beams and longitudinal girders. All these various choices for the stiffening elements, e.g., ribs, floor beams and main girders, can be interchanged, resulting in a great variety of orthotropic panels.
Decks with different stiffnesses in longitudinal and transverse directions are called 'orthotropic'. If the stiffnesses are similar in the two directions, then the deck is called 'isotropic'.
The steel deck-plate-and-ribs system may be idealized for analytical purposes as an orthogonal-anisotropic plate, hence the abbreviated designation “orthotropic.”
Discussion
The stiffening elements can serve several functions simultaneously. They enhance the bending resistance of the plate to allow it to carry local wheel loads and distribute those loads to main girders. They also increase the total cross-sectional area of steel in the plate, which can increase its contribution to the overall bending capacity of the deck (i.e. the deck plate acts as a top flange in a box or I beam girder). Finally, the stiffeners increase the resistance of the plate to buckling.
The same structural effects are also true of the concrete slab in a composite girder bridge, but the steel orthotropic deck is considerably lighter, and therefore allows longer span bridges to be more efficiently designed.
Resistance to use of an orthotropic deck relates mainly to its cost of fabrication, due to the amount of welding involved. In addition, it must be prefabricated rather than assembled on site, which offers less flexibility than in-situ concrete decks. Orthotropic decks have been prone to fatigue problems and to delamination of the wearing surface, which, like the deck, is also often of a very thin material to reduce weight.
Invention
A German Engineer Dr. Cornelis of MAN Corporation was issued German patent No. 847014 in 1948. MAN's design manual was published in 1957 in German. In 1963 AISC published their manual based on North American design practices.
Orthotropic deck bridges
Thousands of orthotropic deck bridges are in existence throughout the world. Despite the savings and advantages (up to 25% of total bridge mass can be saved by reducing deck weight, as the weight reductions extend to cables, towers, piers, anchorages, and so forth), the US has only about 60 such bridge decks in use . About 25% of orthotropic in the US are in California, including the San Mateo-Hayward Bridge, which is one of the first major bridges in the US to be built using an orthotropic deck.
Some very large cable-supported bridges, plus current record span (cable-stayed bridges and suspension bridges) would not be feasible without steel orthotropic decks. The longest or record span box girder, slant-leg bridges; arch bridges; movable bridges and two Norwegian floating bridges all use orthotropic decks.
The Millau Viaduct, a cable-stayed bridge at Millau, France, has the largest orthotropic steel deck area of any single bridge. The lower total gross weight of the superstructure allowed bridge launching from both ends of the Millau Viaduct.
The Akashi Kaikyō Bridge's orthotropic deck allowed the Japanese to build the longest span at about , or 50% longer than the Golden Gate Bridge.
Orthotropic decks permit a very shallow deck depth which reduces the steepness of approach gradients and hence their costs. The form is also widely used on bascule and other moveable bridges where significant savings in the cost of the mechanical elements can be made where a lighter deck is used. The El Ferdan Railway Bridge across the Suez Canal of Egypt is the longest swing bridge in the world. The Erasmus Bridge has an orthotropic deck for both its cable-stayed bridge and bascule span. The Danziger Bridge of New Orleans is a very large vertical lift bridge.
The Mumbai Trans Harbour Link, also called Atal Setu, is India's first orthotropic steel deck bridge. It connects South Mumbai to Navi Mumbai's JNPT (Nhava Sheva) and has reduced travel time between Mumbai and Pune, Navi Mumbai, Goa and other cities in the south east of Pune.
Bridge deck replacements
It is possible to refit a bridge originally designed with a concrete or non-structural deck to use a lighter orthotropic deck, which has been done to preserve or extend the load-carrying life of key or landmark bridges around the world.
It was first utilized in North America in 1975, on the Lions Gate Bridge in Vancouver, which was completed in 1938 with exceptionally light design. The original concrete deck of the North Viaduct of the Lions Gate Bridge was replaced with a lighter and wider orthotropic deck, carried out in sections using a series of short closures of the bridge. Cantilever orthotropic decks allowed the Tamar Bridge to remain open whilst the main deck was replaced in 1999. An ambitious orthotropic replacement of the entire original suspended structure of the main suspension portion of the Lions Gate Bridge was undertaken 2000–2001 and completed without interruption in peak-hour traffic, resulting in the 63-year old bridge, not designed for durability, getting a new lease of life.
Another notable example, San Francisco’s Golden Gate Bridge, completed in 1937, originally used a concrete deck. Salt carried by fog or mist reached the rebar, causing corrosion and concrete spalling. From 1982 to 1986, the original bridge deck, in 747 sections, was replaced with lighter, stronger orthotropic steel deck panels over 401 nights without closing the roadway completely to traffic. The project not only restored the bridge to prime condition but also reduced the deck weight by 12,300 tons (11,160 metric tons).
See also
Bridge deck
References
External links
Turner-Fairbark Highway research center Orthotropic deck article from United States Department of Transportation website
Federal Highway Administration (US Department of Transportation) report on automation of bridge deck section fabrication.
Severn Crossing deck details Illustrations include deck underside and weldpoint diagrams
Western Bridge Engineers Seminar* =orthotropic bridges of California
orthotropic bridges of California* Powerpoint
* (2012) Manual for Design, Construction, and Maintenance of Orthrotropic Steel Decks.
Foreign language search terms
Examples of famous bridges with orthotropic steel decks
Dutch: Erasmus Orthotropic Bridge = Erasmusbrug (Brug = bridge in Dutch)
French: Pont Gustave-Flaubert (Pont = bridge and orthotrope = orthotropic in French)
German: Erasmus-Brücke (Brücke = bridge and orthotrop = orthotropic in German)
Brazilian Portuguese: The Juscelino Kubitschek Bridge (Portuguese: Ponte Juscelino Kubitschek) (Ponte = bridge in Portuguese)
Italian Ponte sullo Stretto di Messina (Ponte = Bridge in Italian)
Norwegian: Nordhordland Bridge = Nordhordlandsbrua (Brua = bridge in Norwegian)
Bridges | Orthotropic deck | Engineering | 1,583 |
11,284,769 | https://en.wikipedia.org/wiki/Quad%20data%20rate | Quad data rate (QDR, or quad pumping) is a communication signaling technique wherein data are transmitted at four points in the clock cycle: on the rising and falling edges, and at two intermediate points between them. The intermediate points are defined by a second clock that is 90° out of phase from the first. The effect is to deliver four bits of data per signal line per clock cycle.
In a quad data rate system, the data lines operate at twice the frequency of the clock signal. This is in contrast to double data rate systems, in which the clock and data lines operate at the same frequency.
Quad data rate technology was introduced by Intel in its Willamette-core Pentium 4 processor, and was subsequently employed in its Atom, Pentium 4, Celeron, Pentium D and Core 2 processor ranges. This technology has allowed Intel to produce chipsets and processors that can communicate with each other at data rates expected of the traditional front-side bus (FSB) technology running from 400 MT/s to 1600 MT/s, while maintaining a lower and thus more stable actual clock frequency of 100 MHz to 400 MHz.
Background
The reasons for operating in QDR rather than DDR are very different than those cited for operating in DDR rather than single data rate. Going to DDR allowed manufacturers of memory to send data at the same rate as the clock beat (one data-line transition for every clock-line transition), while SDR could only send data at the rate of the clock cycle (one data-line transition for every clock-line rising edge). A naive implementation of QDR would result in the data rate being higher than the clock rate, negating any simple electrical advantage.
The advantages for QDR arise when dealing with bus contention. On a modern computer, there may be several CPUs and several I/O devices, all competing for accesses to the memory. To handle this contention properly, modern systems aim to enable signals to propagate between all connected components within a single clock cycle, while setting a firm limit on the maximum clock rate. However, once the contention has been dealt with, the data transfer can be treated as a simple point-to-point unidirectional transfer. In such a simple transfer, it is no longer essential for signals to fully propagate within a cycle; they merely need to arrive coherently, marshaled by a special signal called "strobe". This reduced requirement on signal integrity allows the QDR data transfer to occur at twice the speed of the clock, as opposed to at the same speed as the clock as in DDR.
See also
Double data rate
Pumping (computer systems)
GDDR5X
References
Digital electronics | Quad data rate | Engineering | 554 |
55,948,299 | https://en.wikipedia.org/wiki/NGC%20965 | NGC 965 is a spiral galaxy approximately 294 million light-years away from Earth in the constellation of Cetus. It was discovered by American astronomer Ormond Stone in 1886 with the 26" refractor at Leander McCormick Observatory.
Soviet/Russian astrophysicist Vorontsov-Velyaminov B. and Arhipova V. P. have noted in their "Morphological Catalogue of Galaxies" that NGC 965 "looks almost like two flattened galaxies i=I and i=III in contact and very disturbed".
See also
List of NGC objects (1–1000)
References
External links
SEDS
Spiral galaxies
Cetus
965
9666
Astronomical objects discovered in 1886
Discoveries by Ormond Stone | NGC 965 | Astronomy | 144 |
4,658,306 | https://en.wikipedia.org/wiki/Magnetic%20resonance%20microscopy | Magnetic resonance microscopy (MRM, μMRI) is magnetic resonance imaging (MRI) at a microscopic level down to the scale of microns. The first definition of MRM was MRI having voxel resolutions of better than 100 μm.
Nomenclature
Magnetic resonance microscopy refers to very high resolution MRI imaging (down to nanometer scale, in some cases comparable with histopathology). The term MR microscopy is most widely used by the High Resolution Magnetic Resonance Imaging department at Duke University, headed by Dr. G. Allan Johnson, and the National High Magnetic Field Lab group at AMRIS, University of Florida/Florida State University.
Differences between MRI and MRM
MRM represent a higher evolution of MRI
MRM employs a much stronger magnetic field, which is conducted on a much smaller scale.
Resolution: Medical MRI resolution is typically about 1 mm; the desired resolution of MRM is 100 μm or smaller to 10 μm, comparable with histology.
Specimen size: Medical MRI machines are designed so that a patient may fit inside. MRM chambers are usually small, typically less than 1 cm3 for the imaging of rats, mice and rodents. BrukerBio Spin Company, Billerica, MA specialises in the supply of different microimaging probes (5 mm – 75 mm) for ex vivo/in vivo imaging of excised biological samples.
Current status of MRM
Although MRI is very common for medical applications, MRM is still developing in laboratories up to resonance frequencies of 1000 MHz[1] (for nuclear magnetic resonance; electron magnetic resonance commonly operates at much higher frequencies). The major barriers for practical MRM include:
Magnetic field gradient: High gradient focus of magnetic resonance in a smaller volume (smaller point spread function), results in a better spatial resolution. The gradients for MRM are typically 50 to 100 times those of clinical systems. However, the construction of radio frequency (RF) coils used in MRM does not allow ultrahigh gradients.
Sensitivity: Because the voxels for MRM can be 1/100,000 of those in MRI, the signal is proportionately weaker.
Alternative MRM
Magnetic resonance force microscopy (MRFM) has nm-scale resolution. It improves the sensitivity issue by introducing microfabricated cantilevers to measure tiny signals. The magnetic gradient is generated by a micrometre-scale magnetic tip, yielding a typical gradient 10 million times larger than those of clinical systems. This technique is still in the early phase of development. Because the specimen needs to be in a high vacuum at cryogenic temperatures, MRFM can be used only for solid state materials.
References
External links
Introduction to Magnetic Resonance Microscopy Auditory Research Laboratory at the Univ. of North Carolina.
Magnetic resonance imaging | Magnetic resonance microscopy | Chemistry | 558 |
28,639,331 | https://en.wikipedia.org/wiki/Triangular%20array | In mathematics and computing, a triangular array of numbers, polynomials, or the like, is a doubly indexed sequence in which each row is only as long as the row's own index. That is, the ith row contains only i elements.
Examples
Notable particular examples include these:
The Bell triangle, whose numbers count the partitions of a set in which a given element is the largest singleton
Catalan's triangle, which counts strings of matched parentheses
Euler's triangle, which counts permutations with a given number of ascents
Floyd's triangle, whose entries are all of the integers in order
Hosoya's triangle, based on the Fibonacci numbers
Lozanić's triangle, used in the mathematics of chemical compounds
Narayana triangle, counting strings of balanced parentheses with a given number of distinct nestings
Pascal's triangle, whose entries are the binomial coefficients
Triangular arrays of integers in which each row is symmetric and begins and ends with 1 are sometimes called generalized Pascal triangles; examples include Pascal's triangle, the Narayana numbers, and the triangle of Eulerian numbers.
Generalizations
Triangular arrays may list mathematical values other than numbers; for instance the Bell polynomials form a triangular array in which each array entry is a polynomial.
Arrays in which the length of each row grows as a linear function of the row number (rather than being equal to the row number) have also been considered.
Applications
Romberg's method can be used to estimate the value of a definite integral by completing the values in a triangle of numbers.
The Boustrophedon transform uses a triangular array to transform one integer sequence into another.
In general, a triangular array is used to store any table indexed by two natural numbers where j ≤ i.
Indexing
Storing a triangular array in a computer requires a mapping from the two-dimensional coordinates (i, j) to a linear memory address. If two triangular arrays of equal size are to be stored (such as in LU decomposition), they can be combined into a standard rectangular array. If there is only one array, or it must be easily appended to, the array may be stored where row i begins at the ith triangular number Ti. Just like a rectangular array, one multiplication is required to find the start of the row, but this multiplication is of two variables (i*(i+1)/2), so some optimizations such as using a sequence of shifts and adds are not available.
See also
Triangular number, the number of entries in such an array up to some particular row
References
External links | Triangular array | Mathematics | 528 |
62,346,448 | https://en.wikipedia.org/wiki/Lefty%27s | Lefty's is a retail store on Pier 39 in San Francisco, specializing in products for left-handed people. It was opened in 2008 by Margaret Majua. However, the history of a left-handed store on Pier 39 dates back to 1975, with the opening of Left-Hand World, which closed ten years later. The product line, all designed by Majua, include stationery products, such as notebooks with the binding on the right side, and a pen which allows left-handed writers to see what they had just written without smearing it; cooking utensils for the left hand; and clothing with slogans for left-handers. Lefty's, which sells its products both in-store and online, is one of just a few stores for left-handed people worldwide, and currently the oldest.
References
External links
2008 establishments in California
Retail companies based in California
Handedness
Companies based in San Francisco
American companies established in 2008
Retail companies established in 2008 | Lefty's | Physics,Chemistry,Biology | 201 |
355,791 | https://en.wikipedia.org/wiki/Tactical%20designator | Police units in the United States tend to use a tactical designator (or tactical callsign) consisting of a letter of the police radio alphabet followed by one or two numbers. For example, "Mary One" might identify the head of a city's homicide division. Police and fire department radio systems are assigned official callsigns, however. Examples are KQY672 and KYX556. The official headquarters callsigns are usually announced at least hourly, and more frequently by Morse code.
The United States Army uses tactical designators that change daily. They normally consist of letter-number-letter prefixes identifying a unit, followed by a number-number suffix identifying the role of the person using the callsign.
See also
Brevity code
Call sign
Glossary of military abbreviations
List of aviation, avionics, aerospace and aeronautical abbreviations
List of aviation mnemonics
List of government and military acronyms
ITU prefix
NATO phonetic alphabet
Pan-pan
Procedure word
Pseudonym
References
Military communications
Law enforcement in the United States | Tactical designator | Engineering | 211 |
5,558,590 | https://en.wikipedia.org/wiki/Shapiro%20inequality | In mathematics, the Shapiro inequality is an inequality proposed by Harold S. Shapiro in 1954.
Statement of the inequality
Suppose is a natural number and are positive numbers and:
is even and less than or equal to , or
is odd and less than or equal to .
Then the Shapiro inequality states that
where and . The special case with is Nesbitt's inequality.
For greater values of the inequality does not hold, and the strict lower bound is with .
The initial proofs of the inequality in the pivotal cases and rely on numerical computations. In 2002, P.J. Bushell and J.B. McLeod published an analytical proof for .
The value of was determined in 1971 by Vladimir Drinfeld. Specifically, he proved that the strict lower bound is given by , where the function is the convex hull of and . (That is, the region above the graph of is the convex hull of the union of the regions above the graphs of and .)
Interior local minima of the left-hand side are always .
Counter-examples for higher n
The first counter-example was found by Lighthill in 1956, for :
where is close to 0. Then the left-hand side is equal to , thus lower than 10 when is small enough.
The following counter-example for is by Troesch (1985):
(Troesch, 1985)
References
External links
Usenet discussion in 1999 (Dave Rusin's notes)
PlanetMath
Inequalities | Shapiro inequality | Mathematics | 299 |
1,540,855 | https://en.wikipedia.org/wiki/Translation%20management%20system | A translation management system (TMS), formerly globalization management system (GMS), is a type of software for automating many parts of the human language translation process and maximizing translator efficiency. The idea of a translation management system is to automate all repeatable and non-essential work that can be done by software/systems and leaving only the creative work of translation and review to be done by human beings. A translation management system generally includes at least two types of technology: process management technology to automate the flow of work, and linguistic technology to aid the translator.
In a typical TMS, process management technology is used to monitor source language content for changes and route the content to various translators and reviewers. These translators and reviewers may be located across the globe and typically access the TMS via the Internet.
Translation management systems are most commonly used today for managing various aspects translation business.
Naming
Although translation management systems (TMS) seems to be the currently favoured term in the language localisation industry, these solutions are also known as globalization management systems (GMS) or global content management systems (GCMS). They work with content management systems (CMS) as separate, but linked programs or as simple add-ons that can answer specific multilingual requirements.
Overview
A TMS typically connects to a CMS to manage foreign language content. It tends to address the following categories in different degrees, depending on each offering:
Business administration: project management, resource management, financial management. This category is traditionally related to enterprise resource planning (ERP) tools.
Business process management: workflow, collaboration, content connectors. This category is traditionally the domain of specialised project management tools.
Language management: integrated translation memory, webtop translation tools, customer review and markup. This is traditionally performed with specialised translation tools.
CMS excels at process management while ignoring business management and translation tools, which are strongholds of TMS.
Features and benefits
The measurable benefits of using a TMS are similar to those found in a CMS, but with a multilingual twist: the localization workflow is automated, thus reducing management and overhead costs and time for everyone involved; localization costs are reduced, time to market is decreased and translation quality improves; with the evolution of cloud computing, projects can be launched from any corporate location instead of one centralized headquarters; finally, the cooperation between headquarters, third party vendors, and national branches increases thanks to more thorough reporting.
A typical TMS workflow goes through the following steps:
Change detection of updated or new materials is a must either with standard off-the-shelf CMSs or with the use of custom-developed connectors in the case of proprietary systems. Content is automatically extracted from the CMS and packaged for transmission to the TMS. In some cases, file manipulation may be needed for later analysis and translation. Project managers customise workflows to match their business needs. Every participant in the workflow receives a notification where there is new work to be done, and a unique number is assigned to every project and every task for traceability. Translators and revisers work either online or offline and their queries and comments are tracked through the system. Translators or revisers receive comments from the customer's in-country reviewers to verify and implement any corrections. After the documents are approved, the TM is automatically updated for later reuse. Finally, the translated materials are returned into their CMS for publishing and productivity and efficiency metrics are available through reports.
Linguistic technology generally includes at least translation memory and terminology database; some systems also integrate machine translation technology. Translation memory is a database of all previously translated sentences. While a translator performs translation, he or she is automatically prompted with similar sentences from the memory that were previously translated. A terminology database is a glossary that contains specific words and phrases and their context-appropriate translations.
A machine translation system is a program that uses natural language processing technology to automatically translate a text from one language to another.
Future
Future trends in TMSs include:
interoperation with more CMS offerings: content managers should be able to order translations within their own environment
tie in with text authoring environments: for existing multilingual content leverage against new writing
incorporation of business management functions: to preview the localization cost and timeframe
integration with enterprise systems: general ledger applications and sales force automation tools
Target markets and licensing
TMS vendors target two main buyers when marketing and selling their products. On the one hand, software developer-only companies attract content producers, and sell their offering with no strings attached. On the other hand, software developers can also be language service providers (LSPs), so they offer their language services over their custom-made technological offering for easier customer integration. The latter is commonly referred to as a captive solution, meaning that buyers must use the TMS developer's language services in order to take advantage of their platform.
Content producers with preferred or previous language service agreements to third LSPs may prefer to maintain their independence and purchase software licences only. However, a combined option of technology solution and language services in one package is bound to be more cost effective. Similarly, LSPs may prefer to contact technology vendors who are not part of the competition, offering also language services. Many LSPs got nervous when SDL bought Trados in 2005, becoming the biggest translation technology provider, while still having language services as part of their activities. As a result of this, competitive cloud translation management systems that combine TMS functionality with CAT tools and online translation editors, started making their way to the market.
See also
Computer-assisted translation
Internationalization and localization
References
Translation software
Content management systems
Internationalization and localization | Translation management system | Technology | 1,163 |
35,198,686 | https://en.wikipedia.org/wiki/Paolo%20Cirio | Paolo Cirio is a conceptual artist, hacktivist and cultural critic.
Cirio's work embodies hacker ethics, such as open access, privacy policies, and the critique of economic, legal, and political models. He received a number of legal threats for his Internet art performances, including practices such as hacking, piracy, leaking sensitive information, identity theft, and cyber attacks.
Paolo Cirio is known for having exposed over 200,000 Cayman Islands offshore firms with the work Loophole for All in 2013; the hacking of Facebook through publishing 1 million users on a dating website with Face to Facebook in 2011; the theft of 60,000 financial news articles with Daily Paywall in 2014 and of e-books from Amazon.com with Amazon Noir in 2006; defrauding Google with GWEI in 2005; and the obfuscation of 15 million U.S. criminal records with Obscurity in 2016; exposing over 20,000 patents of technology enabling social manipulation in 2018. Recently, in 2020, he pirated over 100,000 Sotheby’s auction records in Derivatives and he attempted to profile 4000 French police officers with facial recognition in Capture. His early works include his cyber attacks against NATO and reporting on its military operations since 2001 .
Career
Paolo Cirio has won a number of awards, including the Golden Nica first prize at Ars Electronica in 2014; the Eyebeam Fellowship in 2012; and the Transmediale second prize 2008, among others.
Cirio has exhibited in international museums and institutions, he regularly gives public lectures and workshops at leading universities, and his artworks have been covered by hundreds of media outlets worldwide.
2001 - 2004
In 2002, Cirio's first international action was called Anti-NATO Day. As an act of Hacktivism he staged a virtual sit-in (DDoS attack) in the NATO website through a Flash Player script. The Canadian Department of National Defence investigated the action and the Eisenhower Institute used it as a case study to identify future vulnerabilities in space security. Cirio promoted the action through an anti-war web portal called StopTheNato.org, which he launched in 2001 and updated periodically until 2006.
In 2004, Cirio joined the Illegal Art Show network, which organized street art happenings in Italy in line with the Temporary Autonomous Zone philosophy. They occupied public spaces and invited artists to create and show artworks during the events. Cirio created several street art pieces and organized three such events independently: two in Turin in 2004 and a third in London in 2005.
2005 - 2007
In 2005, Cirio hacked Google's AdSense service by creating internet bots for a click fraud in order to buy Google's shares with its own money. In an attempt to stop the project, Google sent a cease and desist letter to the artists mentioning legal consequences for the project. Cirio worked on the project Google Will Eat Itself (GWEI) in conjunction with Alessandro Ludovico and Ubermorgen. The project questioned the information monopoly of Google and its revenue model.
In 2006 he eluded Amazon.com's protections with internet bots exploiting a vulnerability of the "search inside" service. He scraped complete texts of books, reassembled them into PDF files, and redistributed them for free. The company refused to comment on the action. In collaboration with Alessandro Ludovico and Ubermorgen, Cirio created the project Amazon Noir to criticize the abuse of copyright laws for digital content misappropriated by private corporations.
Face to Facebook, Amazon Noir and Google Will Eat Itself together form the Hacking Monopolism Trilogy.
2008 - 2010
Between 2008 and 2010, Cirio worked on experimental storytelling, involving actors and audiences to present real facts and issues through fictional stories across multiple media platforms. He called this technique of documentary fiction "Recombinant Fiction." This socially engaged genre of transmedia storytelling has resulted in two projects: Drowning NYC (2010) and The Big Plot (2009).
In 2010, during the Great Recession, Cirio created the piece P2P Gift Credit Card - Gift Finance. Cirio issued thousands of illicit VISA credit cards to design a creative monetary policy, named "Gift Finance", which is a participatory and interest-free basic income guarantee system. In the following years, he presented the projects in relation to the economic recession and the related Occupy Wall Street protests.
2011 - 2012
Since 2011, Cirio has been addressing the cultural shift and mainstream media attention toward popular perceptions of privacy and ownership of public and personal information, with the projects Street Ghosts, Persecuting.US, and Face to Facebook. The methodology used to create these artworks was eventually formalized in a series called Anti-Social Sculptures.
In 2011, Cirio created Face to Facebook with Alessandro Ludovico. For this piece, Cirio collected one million Facebook profiles, filtered them with artificial intelligence for facial recognition software, and published 250,000 of them onto Lovely-Faces.com, a mock dating website designed by Cirio, with the profiles sorted according to facial expressions. This resulted in eleven lawsuit threats, five death threats, and four legal letters from Facebook . The legal repercussions were integrated into the artwork as a component part of a creative project within an expanded field. Within a few days, the project was covered by over a thousand media outlets from around the world including CNN, Fox News, Tagesschau, and Apple Daily.
With the Street Ghosts project in 2012, Cirio recontextualized photos of individuals found on Google Street View, by printing and posting life-sized pictures of people in the exact locations where they were photographed. The posters were wheatpasted on the walls of public buildings without authorization. These interventions took place in public spaces of several major cities, including London, Berlin, and New York.
In 2012, his web project Persecuting.US profiled the political affiliations of over one million Americans who used Twitter during the months leading up to the 2012 United States presidential election. Cirio appropriated the data and algorithmically determined users’ political affiliations to raise awareness on voter profiling and polarization in social bubbles that can be targeted for political manipulation.
2013 - 2014
In 2013, Cirio investigated offshore financial systems with the project Loophole for All. The project made public the list of all the companies registered in the Cayman Islands for the first time, exposing tax evasion practices by counterfeiting Certificate of Incorporation documents signed with his name. This information was published on the website Loophole4All.com, engaging international participation through selling the real identities of anonymous Cayman companies for 99 cents. This provocation elicited reactions from Cayman authorities and global banks as well as legal threats by multinational companies, international law firms, and local Cayman businesses. After three weeks of selling conceptual and subversive artworks in the form of limited editions of firms’ identities, PayPal suspended the account, claiming the sales activity was in violation of PayPal's Acceptable Use Policy. The project offered a creative approach to democratizing and making-known the financial privileges afforded to moneyed individuals and multinational corporations. In 2014 the project won the Golden Nica, first prize of Prix Ars Electronica.
In 2014, Cirio created the Global Direct project, a creative political philosophy that the artist outlined for worldwide participatory democracy within the potentials offered by the Internet. To illustrate the conceptual work, the artist drew a series of fifteen Organizational charts to inspire values and functions for a global and participatory society. The fifteen diagrams of Global Direct were informed by the artist’s research into the social science of ancient, contemporary, and emergent democracy.
In 2014 Cirio created Daily Paywall by hacking the paywall of The Wall Street Journal, Financial Times, and The Economist. Through his paid subscriptions and Scripting language hack, he obtained over 60,000 news articles published during the course of 2014. The pay-per-view content was republished for free on the website DailyPaywall.com and the artist proposed to pay people to read featured financial news articles. Cirio conceived a provocative sharing economy model, where crowdsource was put in place to allow and incentivize people to access information on economic matters. Using this system, readers were able to earn money for every quiz about featured news they correctly completed, and journalists were able to claim compensation for their work. Everyone could donate any amount to crowdfund the system. After a few days, the ISP hosting DailyPaywall.com disabled the site after receiving complaints of international Copyright infringement from Pearson PLC, the education and publisher company and owner of the Financial Times and The Economist. Additionally The Wall Street Journal proceeded to terminate the artist’s subscription due to a violation of their Terms of Service. In 2016, Pearson sold both The Economist and the Financial Times and Cirio republished the whole content of DailyPaywall.com. He entire artistic act was pre-scripted as a performance for illustrating critical issues on the Information economy that Cirio outlined within the launch of the project.
2015 - 2016
During the spring of 2015, Cirio conducted the street art campaign OVEREXPOSED concerning the aftermath of Edward Snowden’s global surveillance disclosures. He disseminated on public walls unauthorized photos of high-ranking U.S. intelligence officials of the NSA, CIA and FBI, who were accountable for political measures or advocacy for mass surveillance and espionage programs. The photos, mostly selfies from Facebook and Twitter accounts of civilians, were rendered with a particular technique called High Definition Stencils invented by the artist for the street art campaign that took place in NYC, London, Berlin and Paris between April and May 2015. The intervention generated media coverage and public interest internationally and particularly in Germany
in connection to the German Parliamentary Committee investigating the NSA spying scandal.
In 2016, Cirio created the project Obscurity in which he obfuscated over 10 million online mugshots and the criminal records of victims of mass incarceration in United States. The project addressed the unregulated mug shot publishing industry that anonymous internet companies exploit in order to shame and blackmail people who have been arrested in the U.S. regardless of their charges and trial verdicts. Cirio targeted six mugshot websites and blurred millions of mugshots and shuffled names listed. In response he received support from mugshot extortion victims and was subject to a legal threat from Mugshots.com, an anonymous firm in Nevis, and US Data ltd., a Texan firm owning a few mugshot websites. With Obscurity, Cirio questioned the Right to Be Forgotten law, which has been opposed by major search engine companies in the U.S. Ultimately, to point out the accountability of search engines in exposing personal sensitive information, Cirio designed the campaign Right2Remove.us to introduce a privacy policy adapting the Right to Be Forgotten law to the United States. With the Right to Remove policy, Cirio suggested types of sensitive personal data that should be removed from online search results to protect specific categories of vulnerable individuals. The campaign formed a community of activists for the removal of online criminal records and a form of Right to be Forgotten in United States.
2017 - 2018
During 2017, Cirio curated the Evidentiary Realism exhibitions in NYC and Berlin art galleries featuring artists engaged in investigative, forensic, and documentary art. He articulated a particular form of realism in art that portrays and reveals evidence through investigation and research-based work. The exhibitions included historical artists such as Hans Haacke, Mark Lombardi, Jenny Holzer, and Harun Farocki. A collection of essays about the works presented were published in the book Evidentiary Realism .
In 2018, Cirio published the project Sociality with over 20000 patents of algorithms, devices, and interfaces of social media, online advertising, and other Internet technologies, that he collected from Google Patents. He then rated the patents for finding the most potentially socially harmful ones. A selection of patents ordered by categories such as discrimination, polarization, addiction, deception, control, censorship, and surveillance were published on The Coloring Book of Technology for Social Manipulation . On the project’s website, visitors are invited to share, flag, and ban these patents in relation to the regulation of the information technology for monitoring and manipulating social behaviors. Furthermore, as a form of protest, Cirio posted printed patent titles and images at the main universities in U.S. such as at Harvard, MIT, Stanford, Berkley, and Columbia. This project responded to the scandals of Cambridge Analytica and Youtube algorithms that broke in 2018 and broadly it documents the history of the Internet with the advent of targeted advertising, corporate surveillance, and information feed filtered by artificial intelligence.
2019 - 2020
During the fall of 2019, Cirio presented three new projects related to his concept of Internet Photography focusing on the economic and legal aspects of images circulating online. Rather than addressing privacy, with these projects Cirio looked at the relations between cultural and economic values of online photos. In particular with the artwork Attention, Cirio addressed subtle forms advertising by Instagram influencers. Cirio collected hundreds of photos by online influencers promoting controversial products without disclaimers and in partnership with the University of Maastricht he investigated the legal implications of moderating and regulating such subtle advertising.
In the spring of 2019 with his work Foundations he put forward an aesthetics of contemporary social complexity and the use of flowcharts as an artistic medium for seeing and engaging with such aesthetics. He published a monograph of his artworks using flowcharts to work with socio-economic information systems and a separate text book for the project Foundations where he curated a selection of artworks, exhibitions, and publications from the history of conceptual art to identify an ontology of an aesthetics of social complexity.
In June 2020, Cirio launched the project Derivatives online, with a database of over 100,000 Sotheby’s auction records he assembled over several years. Cirio overlaid the auction prices on the images works to sell them as digital artworks on the website Art-Derivatives.com for a fraction of the value set at the auctions. Cirio designed a "future" financial derivative contract for the sale of his derivative works. By betting against future prices of derivative works, with Cirio’s concept everyone can ironically participate in the financialization of art. In addition, the project campaigns for enacting more transparency and fairness in the art market. In order to provoke regulation, Cirio has investigated secrecy and manipulation of art auctions with extensive research . This project was reported by the international outlets as a controversial and investigative work.
In October 2020, Cirio created the project Capture with 4000 faces of French police officers assembled by a facial recognition system. Further, Cirio aimed to crowdsource the identification of the officer on his platform Capture-Police.com. In response the interior minister Gérald Darmanin and police unions forced the take down of the project both online and at the exhibition in the French art institution Le Fresnoy. This case of censorship of Cirio’s work was largely reported internationally. This provocation was designed by Cirio to promote his campaign #BanFacialRecognitionEU. In 2021, Cirio concluded the campaign to ban facial recognition technology in Europe by delivering his legal research and complaint to the European Commission and EDPS with over 50,000 signatures supporting his petition.
2021 - 2023
On October 9, 2021, Cirio established the first international climate crime tribunal though a solo exhibition at the historical museum of Certosa di San Giacomo in Capri. His concept of Climate Tribunal combines a body of works about Climate Justice from a legal and economic standpoint. Cirio gathered data, graphs, and images as evidence to hold major oil, gas, and coal companies responsible for their greenhouse gas emissions. The historical scientific, legal, and economic evidence is presented by Cirio through fine artworks, online platforms, public events, and interviews with experts.
Cirio’s Climate Tribunal integrates the science of the attribution of recent climate change with the legal concept of environmental personhood, and the rights of nature jurisprudential theory, informed by climate change litigation, ecocide bills, and global climate treaties. Central to Cirio’s concept is the historical study Carbon Majors Database by the Climate Accountability Institute, the first to establish precise responsibilities for each international fossil fuel firm, and deduced that the major 100 oil, gas and coal producers have generated over 70% of greenhouse gas emissions.
For Dutch Design Week 2021, Cirio launched the project Extinction Claims addressing ongoing Mass Extinction. On Extinction-Claims.com Cirio aggregated data on 40,000 vulnerable species and the public can claim financial compensation from major fossil fuel companies on behalf of endangered species through an algorithm that Cirio made to calculate funding for the preservation of endangered species whose natural environments are threatened by climate change. Extinction Claims was part of a larger campaign for the introduction of a Carbon Tax dedicated to the preservation of ecosystems vulnerable to climate change. The project was awarded and presented at Fondazione Merz in 2022.
Between 2022 and 2023, Cirio received three grants to expand the conceptual framework of the Climate Tribunal, from Strasbourg University, New York University Tandon School of Engineering, and Hamburg University. Through these commissions, Cirio created platforms to engage online users with the Carbon Majors Database and Climate Justice, including the projects Flooding-NYC-Claims.net and Footprint-Justice.com. In January 2023, Cirio launched the Climate Class Action, a campaign aimed at promoting lawsuits that would enable all citizens to seek compensation for personal damages caused by climate change. Cirio created the platform ClimateClassAction.com, where everyone can calculate monetary compensation based on the emissions of major fossil fuel companies.
In 2024, as a result of his research on climate change, Cirio published the book Climate Tribunal, which includes philosophical reflections, resources on climate litigation, and political-economic evidence against the fossil fuel industry.
Awards
Selected awards include:
Prix Ars Electronica 2005, Honorary Mention Net Vision category, for GWEI
ibizagrafica 2006, Honorary Mention, for Amazon Noir
St. Gilgen International School Media Award, 2006, for Amazon Noir
IBM AWARD FOR NEW MEDIA/Stuttgarter Filmwinter, 2007, for Amazon Noir
Transmediale Award 2008, Second Prize, for Amazon Noir
Cairo Prize 2009, Nominated, for Open Society Structures
Prix Ars Electronica 2011, Award of Distinction, for Face to Facebook
Share Festival Prize 2011, First Prize, for Face to Facebook
Eyebeam 2012, Fellowship in New York City
Prix Ars Electronica 2014, Golden Nica, for Loophole for All
Notes
Further reading
Exhibition catalogue.
Details.
Exhibition catalogue.
Exhibition catalogue.
Exhibition catalogue. .
Exhibition catalogue.
External links
paolocirio.net
Paolo Cirio Live at The Influencers
1979 births
New media artists
Net.artists
Street artists
Institutional Critique artists
Italian contemporary artists
Italian conceptual artists
Artists from Turin
Living people | Paolo Cirio | Technology | 3,855 |
74,640,975 | https://en.wikipedia.org/wiki/Unilever%20Research%20Laboratorium | The Unilever Research Laboratorium was a nutrition and human biology research centre in South Holland, owned by Unilever, and since November 2019, has been a private science park.
History
Construction
At the time of construction in 1956, Vlaardingen was the third-busiest port in the Netherlands, situated on the Nieuwe Maas.
On 14 February 1945, a neighbouring Unilever factory was set up as a V-1 launching site, with another site at Ypenburg, on the coast. The site was consequently attacked by RAF Typhoon aircraft on 23 March 1945. These were some of the last V-1 missiles launched against England.
The neighbouring factory closed in 2008. Research by Unilever in the Netherlands occurred during the war at Zwijndrecht, Netherlands.
Opening
The site was officially opened in November 1956 by Willem Drees, the Dutch prime minister. Another research site was at Bahrenfeld in Germany.
The site presented the Unilever Research Prize for over 60 years when owned by Unilever Benelux.
Current site
On 6 October 2016, Unilever announced that the site would close. The site closed in November 2019 and is now a private science park.
Research
In 1968, the centre found the protein miraculin, as well as researchers at the Florida State University College of Human Sciences. Other work made by Henk Van der Wel into the biochemistry of sweetness sensing was published in Chemical Senses.
By genetically-modifying a bacterium, the genes for making thaumatin were added, in 1980.
Visits
On 1 April 1969, a new laboratory was opened by Prince Claus of the Netherlands.
On 5 December 2016 Martijn van Dam, State Secretary for the Ministry of Economic Affairs and Climate Policy, visited.
Former employees
David Adriaan van Dorp, in 1967 worked with University College Cardiff
See also
Monell Chemical Senses Center
References
1956 establishments in the Netherlands
2019 disestablishments in the Netherlands
Biochemistry research institutes
Buildings and structures in South Holland
Economy of South Holland
Food industry in the Netherlands
Food science institutes
Food technology organizations
History of Vlaardingen
Industrial buildings completed in 1956
Nutrition in the Netherlands
Research institutes established in 1956
Research institutes in the Netherlands
Science parks in the Netherlands | Unilever Research Laboratorium | Chemistry | 453 |
10,566,571 | https://en.wikipedia.org/wiki/Heronry | A heronry, sometimes called a heron rookery, is a breeding ground for herons.
Notable heronries
Although their breeding territories are often on more protected small islands in lakes or retention ponds, herons breed in heronries (or also called rookeries, especially since other birds join them like spoonbills, storks, and cormorants). Some of the notable heronries are:
Asia
Kaggaladu Heronry is in Karnataka state of India. This heronry, in the Tumkur district of Karnataka, was first made known to the outside world in 1999 by members of the Tumkur-based NGO Wildlife Aware Nature Club.
Europe
Cleeve Heronry (), in a woodland near the village of Cleeve in North Somerset, UK.
Hilgay Heronry () is in Norfolk. It is situated in a small copse on the edge of The Fens in the UK. An average of c. 40 pairs of grey heron nests each year at this site, in ash (Fraxinus excelsior) and European larch (Larix decidua) trees.
North America
The Florida Everglades in south Florida, of the United States. Thousands of birds, including herons, egrets, spoonbills, and storks, nest in mangroves (genus Rhizophora).
See also
Bird colony
Rookery
References
External links
Herons
Reproductive ecology | Heronry | Biology | 294 |
4,069,279 | https://en.wikipedia.org/wiki/IEC%2061511 | IEC standard 61511 is a technical standard which sets out practices in the engineering of systems that ensure the safety of an industrial process through the use of instrumentation. Such systems are referred to as Safety Instrumented Systems. The title of the standard is "Functional safety - Safety instrumented systems for the process industry sector".
Scope
The process industry sector includes many types of manufacturing processes, such as refineries, petrochemical, chemical, pharmaceutical, pulp and paper, and power. The process sector standard does not cover nuclear power facilities or nuclear reactors. IEC 61511 covers the application of electrical, electronic and programmable electronic equipment. While IEC 61511 does apply to equipment using pneumatic or hydraulic systems to manipulate final elements, the standard does not cover the design and implementation of pneumatic or hydraulic logic solvers.
This standard defines the functional safety requirements established by IEC 61508 in process industry sector terminology. IEC 61511 focuses attention on one type of instrumented safety system used within the process sector, the Safety Instrumented System (SIS).
History
In 1998 the IEC, which stands for International Electrotechnical Commission published a document, IEC 61508, entitled: “Functional safety of electrical/electronic/programmable electronic safety-related systems”. This document sets the standards for safety-related system design of hardware and software. IEC 61508 is generic functional safety standard, providing the framework and core requirements for sector specific standard. Three sector specific standards have been released using the IEC 61508 framework, IEC 61511 (process), IEC 61513 (nuclear) and IEC 62061 (manufacturing/machineries). IEC 61511 provides good engineering practices for the application of safety instrumented systems in the process sector.
In the United States ANSI/ISA 84.00.01-2004 was issued in September 2004. It primarily mirrors IEC 61511 in content with the exception that it contains a grandfathering clause:
For existing safety instrumented systems (SIS) designed and constructed in accordance with codes, standards, or practices prior to the issuance of this standard (e.g. ANSI/ISA 84.01-1996), the owner/operator shall determine and document that the equipment is designed, maintained, inspected, tested, and operated in a safe manner.
The European standards body, CENELEC, has adopted the standard as EN 61511. This means that in each of the member states of the European Union, the standard is published as a national standard. For example, in Great Britain, it is published by the national standards body, BSI, as BS EN 61511. The content of these national publications is identical to that of IEC 61511. Note, however, that 61511 is not harmonized under any directive of the European Commission.
The Standard
IEC 61511 covers the design and management requirements for SISs throughout the entire safety life cycle. Its scope includes: initial concept, design, implementation, operation, and maintenance through to decommissioning. It starts in the earliest phase of a project and continues through startup. It contains sections that cover modifications that come along later, along with maintenance activities and the eventual decommissioning activities.
The standard consists of three parts:
Framework, definitions, system, hardware and software requirements
Guidelines in the application of IEC 61511-1
Guidance for the determination of the required safety integrity levels
ISA 84.01/IEC 61511 requires a management system for identified SIS. An SIS is composed of a separate and independent combination of sensors, logic solvers, final elements, and support systems that are designed and managed to achieve a specified safety integrity level (SIL). An SIS may implement one or more safety instrumented functions (SIFs), which are designed and implemented to address a specific process hazard or hazardous event. The SIS management system should define how an owner/operator intends to assess, design, engineer, verify, install, commission, validate, operate, maintain, and continuously improve their SIS. The essential roles of the various personnel assigned responsibility for the SIS should be defined and procedures developed, as necessary, to support the consistent execution of their responsibilities.
ISA 84.01/IEC 61511 uses an order of magnitude metric, the SIL, to establish the necessary performance. A hazard and risk analysis is used to identify the required safety functions and risk reduction for specified hazardous events. Safety functions allocated to the SIS are safety instrumented functions; the allocated risk reduction is related to the SIL. The design and operating basis is developed to ensure that the SIS meets the required SIL. Field data are collected through operational and mechanical integrity program activities to assess actual SIS performance. When the required performance is not met, action should be taken to close the gap, ensuring safe and reliable operation.
IEC 61511 references IEC 61508 (the master standard) for many items such as manufacturers of hardware and instruments and so IEC 61511 cannot be fully implemented without reference to IEC 61508. IEC 61511 is the process industry implementation of IEC 61508.
IEC61511 is updated with Edition 2.0
References
Electrical standards
Safety
Industrial processes | IEC 61511 | Physics | 1,058 |
4,642,940 | https://en.wikipedia.org/wiki/Compartment%20%28development%29 | Compartments can be simply defined as separate, different, adjacent cell populations, which upon juxtaposition, create a lineage boundary. This boundary prevents cell movement from cells from different lineages across this barrier, restricting them to their compartment. Subdivisions are established by morphogen gradients and maintained by local cell-cell interactions, providing functional units with domains of different regulatory genes, which give rise to distinct fates.
Compartment boundaries are found across species. In the hindbrain of vertebrate embryos, rhombomeres are compartments of common lineage outlined by expression of Hox genes. In invertebrates, the wing imaginal disc of Drosophila provides an excellent model for the study of compartments. Although other tissues, such as the abdomen, and even other imaginal discs are compartmentalized, much of our understanding of key concepts and molecular mechanisms involved in compartment boundaries has been derived from experimentation in the wing disc of the fruit fly.
Function
By separating different cell populations, the fate of these compartments are highly organized and regulated. In addition, this separation creates a region of specialized cells close to the boundary, which serves as a signaling center for the patterning, polarizing and proliferation of the entire disc. Compartment boundaries establish these organizing centers by providing the source of morphogens that are responsible for the positional information required for development and regeneration.
The inability of cell competition to occur across the boundary, indicates that each compartment serves as an autonomous unit of growth. Differences in growth rates and patterns in each compartment, maintain the two lineages separated and each control the precise size of the imaginal discs.
Cell separation
These two cell populations are kept separate by a mechanism of cell segregation linked to the heritable expression of a selector gene. A selector gene is one that is expressed in one group of cells but not the other, giving the founder cells and their descendants different instructions. Eventually these selector genes become fixed in either an expressed or unexpressed state and are stably inherited to the descendants, specifying the identity of the compartment and preventing these genetically different cell populations from intermixing. Therefore, these selector genes are key for the formation and maintenance of lineage compartments.
Central dogma
The difference in selector gene activity not only establishes two compartments, but also leads to the formation of a boundary between these two that serves as a source of morphogen gradients. In the central dogma of compartments, first, morphogen gradients position founder compartment cells. Then, active/inactive selector genes give a unique genetic identity to cells within a compartment, instructing their fate and their interactions with the neighboring compartment. Finally, border cells, established by short-range signaling from one compartment to its neighboring compartment emit long-range signals that spread to both compartments to regulate the growth and pattering of the entire tissue.
A/P boundary
In 1970, by means of clonal analysis, the Anterior-Posterior boundary was identified. The founder cells, found at the border between parasegments 4 and 5 of embryo, are already determined at the early blastoderm stage and defined into the two populations they will generate by stripes of the engrailed gene.
The selector gene, engrailed (en), is a key determinant in boundary formation between the anterior and posterior compartments. As the wing imaginal disc expands, posterior, but not anterior cells will express engrailed and maintain this expression state as they expand and form the disc. Engrailed mutant clones of posterior origin will gain anterior affinity and move towards the anterior compartment and intermix with those cells. Within the posterior compartment these clones will sort out and form an ectopic border where they meet other posterior cells.
Similarly, a clone of anterior cells expressing engrailed will gain posterior identity and create an ectopic boundary where the clone meets other anterior cells in this compartment.
In addition, to its cell autonomous role in specifying posterior compartment identity, engrailed also has a non-cell autonomous function in the general growth and patterning of the wing disc, through the activation of signaling pathways such as Hedgehog (Hh) and Decapentaplegic (Dpp).
The presence of engrailed in the posterior cells leads to the secretion of the short-range inducer Hh which can cross over to the anterior compartment to activate the long-range morphogen, Dpp. Cells in the posterior compartment produce Hh, but only anterior cells can transduce the signal.
Optomotor-blind (omb) is involved in the transcriptional response of Dpp, which is only required in the anterior cells to interpret Hh signaling for boundary formation and maintenance.
In addition, Cubitus interruptus (Ci), the signal transducer of the Hh signal, is expressed throughout the anterior compartment, particularly in anterior border cells. In posterior cells engrailed prevents the expression of Ci, such it is only expressed in anterior cells and hence only these cells can respond to Hh signaling by up-regulating the expression of dpp.
Loss of engrailed function in posterior cells, results in anterior transformation, where Hh expression is decreased and dpp, ci and patched (ptc) is increased, resulting in the formation of a new A/P boundary, suggesting that en positively regulates hh, while negatively regulating ci, ptc and dpp.
Cell segregation
To explain how anterior and posterior cells are kept separated, the differential adhesion hypothesis proposes that these two cell populations express different adhesion molecules, producing different affinities for each other that minimize their contact.
The selector affinity model proposes that difference in cell affinity between compartments is a result of differential selector gene expression. The presence or absence of selector genes in a given compartment produces compartment-specific adhesion or recognition molecules that are different from those in its counterpart.
For example, engrailed expressed in the posterior, but not the anterior, cells provides the differential affinity that keeps these compartments separately.
It is also possible that this difference in cell adhesion/affinity is not directly due to en expression, but rather to the ability to receive Hh signaling. Anterior cells, capable of Hh transduction, will express given adhesive molecules that would differ from those present in posterior cells, creating differential affinity that would prevent them from intermixing.
This signaling-affinity model is supported by experiments that demonstrate the importance of Hh signaling. Clones mutant for the Smoothened (smo), the gene responsible for transducing Hh signaling, retain anterior-like features, but move into the posterior compartment without any changes in the expression engrailed or invected. This demonstrates that Hh signaling, rather than the absence of en, is what gives cells their compartmental identity. Nonetheless, this signaling-affinity model is incomplete: smo mutant clones of anterior origin that migrate into the posterior compartment, do not completely associate with these cells, but rather form a smooth boundary with these posterior cells. If signaling-affinity were the only factor determining compartment identity, then these clones, which are no longer receiving Hh signaling, would have the same affinity as the other posterior cells in that compartment and be able to intermix with them.
These experiments indicate that although Hh signaling could be having an effect in adhesive properties, this effect is limited to the border cells rather than throughout both compartments.
It is also possible that both compartments produce the same cell adhesion molecules, but a difference in its abundance or activity could result in sorting between the two compartments. In vitro, transfected cells with high levels of a given adhesion molecule will segregate from cells that expressing lower levels of this same molecule.
Finally, differences in cell bond tension could also play a role in the establishment of the boundary and the separation of the two different cell populations. Experimental data has shown that Myosin-II is up-regulated along both the dorsal-ventral and anterior-posterior boundaries in the imaginal wing disc. The D/V boundary is characterized by the presence of filamentous actin and mutations in Myosin-II heavy chain impairs D/V compartmentalization. Similarly, both F-actin and Myosin-II are increased along the A/P boundary, accompanied by a decrease of Bazooka'', which was also observed in the D/V border. The Rho-kinase inhibitor Y-27632, of which Myosin-II is the main target, significantly reduces cell bond tension, suggesting that Myosin-II could be the main effector of this process. In support of the signaling-affinity model, creating an artificial interface between cells with active vs. inactive Hh signaling induces a junctional behavior that aligns the cell bonds of where these opposing cell types meet. Moreover, a 2.5-fold increase in mechanical tension is observed along the A/P boundary, compared to the rest of the tissue. Simulations using a vertex model demonstrate that this increase in cell bond tension is enough to maintain proliferating cell populations in separate compartment boundaries. Parameters used to measure cell bond tension are based cell-cell adhesion and cortical tension input.
It has also been suggested that boundary formation is not a result of differential mechanical tension between the two cell populations, but could be a result of the mechanical properties of the boundary itself.
The level the adhesion molecule, E-cadherin, was unaltered and the biophysical properties of cells between the two compartments were the same. Changes in cell properties, such as an enlarged apical cross-section area, are only observed in anterior and posterior border cells. Along the boundary, orientation of cell divisions was random and there is no evidence that increased cell death or zones of non-proliferating cells are important for maintaining the A/P or D/V boundary.
Future directions
Despite many attempts to identify the adhesion molecules important for the establishment and maintenance of compartment boundaries, none have been identified. Continuation of our understanding of this process will benefit from further experimental data on cell bonds and cortical tension, as well as screens to identify molecules regulating differential cell affinity.
References
Developmental biology | Compartment (development) | Biology | 2,065 |
8,591,705 | https://en.wikipedia.org/wiki/List%20of%20stars%20in%20Lacerta | This is the list of notable stars in the constellation Lacerta, sorted by decreasing brightness.
See also
List of stars by constellation
References
List
Lacerta | List of stars in Lacerta | Astronomy | 31 |
9,664,551 | https://en.wikipedia.org/wiki/Amorphism | An amorphism, in chemistry, crystallography and, by extension, to other areas of the natural sciences is a substance or feature that lacks an ordered form. In the specific case of crystallography, an amorphic material is one that lacks long range (significant) crystalline order at the molecular level. In the history of chemistry, amorphism was recognised even before the discovery of the nature of the exact atomic crystalline lattice structure. The concept of amorphism can also be found in the fields of art, biology, archaeology and philosophy as a characterisation of objects without form, or with random or unstructured form.
Amorphous and Crystalline solid
In the context of solids, amorphous and crystalline are terms used to describe the structure of materials. Amorphous solids are the opposite of crystalline. The atoms or molecules in amorphous substances are arranged randomly without any long-range order. As a result, they do not have a sharp melting point. The phase transition from solid to liquid occurs over a range of temperatures. Some examples include glass, rubber and some plastics.
See also
Glass
Obsidian
References
Bibliography
Crystallography
Physical chemistry | Amorphism | Physics,Chemistry,Materials_science,Engineering | 234 |
28,775,600 | https://en.wikipedia.org/wiki/Microviscosity | Microviscosity, also known as microscopic viscosity, is the friction experienced by a single particle undergoing diffusion because of its interaction with its environment at the micrometer length scale. The concept of microviscosity is intimately related to the concept of single particle diffusion and can be measured using microrheology.
Understanding microviscosity requires an understanding of viscosity and diffusion i.e. macroscopic viscosity and bulk diffusion and where their assumptions break down at the micro to nanometer scale where physicists are still trying to replace phenomenological laws with physical laws governing the behavior of single particle mobility.
In the field of biophysics, a typical microviscosity problem is understanding how a biomolecule's mobility is hindered within a cellular compartment which will depend upon many factors such as the size, shape, charge, quantity and density of both the diffusing particle and all members of its environment.
Microviscosity can be probed by measuring the rotational correlation time of a probe molecule using either fluorescence correlation spectroscopy or the linewidths of the probe's electron spin resonance. The friction experienced by a single particle can be thought of as a microscopic viscosity (microviscosity) and should not necessarily agree with the bulk viscosity since it is a measure of the probe's local friction whereas bulk viscosity analogously would be the measure of an infinitely large probe. Both the crowding density and relative size of each co-solute in a mixture will contribute to the measured microviscosity as assessed by altered translational mobility.
References
Soft matter | Microviscosity | Physics,Materials_science | 332 |
17,404,454 | https://en.wikipedia.org/wiki/Engineering%20fit | Engineering fits are generally used as part of geometric dimensioning and tolerancing when a part or assembly is designed. In engineering terms, the "fit" is the clearance between two mating parts, and the size of this clearance determines whether the parts can, at one end of the spectrum, move or rotate independently from each other or, at the other end, are temporarily or permanently joined. Engineering fits are generally described as a "shaft and hole" pairing, but are not necessarily limited to just round components. ISO is the internationally accepted standard for defining engineering fits, but ANSI is often still used in North America.
ISO and ANSI both group fits into three categories: clearance, location or transition, and interference. Within each category are several codes to define the size limits of the hole or shaft – the combination of which determines the type of fit. A fit is usually selected at the design stage according to whether the mating parts need to be accurately located, free to slide or rotate, separated easily, or resist separation. Cost is also a major factor in selecting a fit, as more accurate fits will be more expensive to produce, and tighter fits will be more expensive to assemble.
Methods of producing work to the required tolerances to achieve a desired fit range from casting, forging and drilling for the widest tolerances through broaching, reaming, milling and turning to lapping and honing at the tightest tolerances.
ISO system of limits and fits
Overview
The International Organization for Standardization system splits the three main categories into several individual fits based on the allowable limits for hole and shaft size. Each fit is allocated a code, made up of a number and a letter, which is used on engineering drawings in place of upper & lower size limits to reduce clutter in detailed areas.
Hole and shaft basis
A fit is either specified as shaft-basis or hole-basis, depending on which part has its size controlled to determine the fit. In a hole-basis system, the size of the hole remains constant and the diameter of the shaft is varied to determine the fit; conversely, in a shaft-basis system the size of shaft remains constant and the hole diameter is varied to determine the fit.
The ISO system uses an alpha-numeric code to illustrate the tolerance ranges for the fit, with the upper-case representing the hole tolerance and lower-case representing the shaft. For example, in H7/h6 (a commonly-used fit) H7 represents the tolerance range of the hole and h6 represents the tolerance range of the shaft. These codes can be used by machinists or engineers to quickly identify the upper and lower size limits for either the hole or shaft. The potential range of clearance or interference can be found by subtracting the smallest shaft diameter from the largest hole, and largest shaft from the smallest hole.
Types of fit
The three types of fit are:
Clearance: The hole is larger than the shaft, enabling the two parts to slide and / or rotate when assembled, e.g. piston and valves
Location / transition: The hole is fractionally smaller than the shaft and mild force is required to assemble / disassemble, e.g. Shaft key
Interference: The hole is smaller than the shaft and high force and / or heat is required to assemble / disassemble, e.g. Bearing bush
Clearance fits
For example, using an H8/f7 close-running fit on a 50mm diameter:
H8 (hole) tolerance range = +0.000mm to +0.039
f7 (shaft) tolerance range = −0.050mm to −0.025mm
Potential clearance will be between +0.025mm and +0.089mm
Transition fits
For example, using an H7/k6 similar fit on a 50mm diameter:
H7 (hole) tolerance range = +0.000mm to +0.025mm
k6 (shaft) tolerance range = +0.002mm to +0.018mm
Potential clearance / interference will be between +0.023mm and −0.018mm
Interference fits
For example, using an H7/p6 press fit on a 50mm diameter:
H7 (hole) tolerance range = +0.000mm to +0.025mm
p6 (shaft) tolerance range = +0.042mm to +0.026mm
Potential interference will be between −0.001mm and −0.042mm.
Useful tolerances
Common tolerances for sizes ranging from 0 to 120 mm
ANSI fit classes (US only)
Interference fits
Interference fits, also known as press fits or friction fits, are fastenings between two parts in which the inner component is larger than the outer component. Achieving an interference fit requires applying force during assembly. After the parts are joined, the mating surfaces will feel pressure due to friction, and deformation of the completed assembly will be observed.
Force fits
Force fits are designed to maintain a controlled pressure between mating parts, and are used where forces or torques are being transmitted through the joining point. Like interference fits, force fits are achieved by applying a force during component assembly.
FN 1 to FN 5
Shrink fits
Shrink fits serve the same purpose as force fits, but are achieved by heating one member to expand it while the other remains cool. The parts can then be easily put together with little applied force, but after cooling and contraction, the same dimensional interference exists as for a force fit. Like force fits, shrink fits range from FN 1 to FN 5.
Location fits
Location fits are for parts that do not normally move relative to each other.
Location interference fit
LN 1 to LN 3 (or LT 7 to LT 21? )
Location transition fit
LT 1 to LT 6
Location fit is for have comparatively better fit than slide fit.
Location clearance fit
LC 1 to LC 11
RC fits
The smaller RC numbers have smaller clearances for tighter fits, the larger numbers have larger clearances for looser fits.
RC1: close sliding fits
Fits of this kind are intended for the accurate location of parts which must assemble without noticeable play.
RC2: sliding fits
Fits of this kind are intended for the accurate location but with greater maximum clearance than class RC1. Parts made to this fit turn and move easily. This type is not designed for free run. Sliding fits in larger sizes may seize with small temperature changes due to little allowance for thermal expansion or contraction.
RC3: precision running fits
Fits of this kind are about the closest fits which can be expected to run freely. Precision fits are intended for precision work at low speed, low bearing pressures, and light journal pressures. RC3 is not suitable where noticeable temperature differences occur.
RC4: close running fits
Fits of this kind are mostly for running fits on accurate machinery with moderate surface speed, bearing pressures, and journal pressures where accurate location and minimum play are desired. Fits of this kind also can be described as smaller clearances with higher requirements for precision fit.
RC5 and R6: medium running fits
Fits of this kind are designed for machines running at higher running speeds, considerable bearing pressures, and heavy journal pressure. Fits of this kind also can be described with greater clearances with common requirements for fit precision.
RC7: Free running fits
Fits of this kind are intended for use where accuracy is not essential. It is suitable for great temperature variations. This fit is suitable to use without any special requirements for precise guiding of shafts into certain holes.
RC8 and RC9: loose running fits
Fits of this kind are intended for use where wide commercial tolerances may be required on the shaft. With these fits, the parts with great clearances with having great tolerances. Loose running fits may be exposed to effects of corrosion, contamination by dust, and thermal or mechanical deformations.
See also
Coiled spring pins
Engineering tolerance
Geometric dimensioning and tolerancing
Interchangeable parts
Statistical interference
References
Mechanical engineering
Metalworking terminology | Engineering fit | Physics,Engineering | 1,622 |
72,399,164 | https://en.wikipedia.org/wiki/Abrothallus%20nephromatis | Abrothallus nephromatis is a widely distributed species of lichenicolous fungus in the family Abrothallaceae. It was formally described as a new species in 2015 by Ave Suija and Sergio Pérez-Ortega. The type specimen was collected near Dawson Falls in Wells Gray Provincial Park (British Columbia, Canada) at an elevation of about , where it was found on a Nephroma parile lichen that itself was growing on a dead trunk of birch tree. The species epithet refers to the host genus, Nephroma.
Abrothallus nephromatis has been collected from Africa (Tanzania, Uganda); Asia (Russian Far East); Australia and New Zealand; Europe (Italy, Norway, Sweden), Greenland, and North America (Canada, USA). It is distinguished from the similar species Abrothallus boomii by its eight-spored asci and narrower conidia, and from Abrothallus welwitschii by its smaller ascomata and smaller ascospores. The recorded hosts of the fungus are Nephroma parile, N. helveticum, N. rufum, and N. tropicum.
References
nephromatis
Lichenicolous fungi
Fungi described in 2015
Fungi of Asia
Fungi of Africa
Fungi of Australia
Fungi of Greenland
Fungi of New Zealand
Fungi of Europe
Taxa named by Ave Suija
Fungus species | Abrothallus nephromatis | Biology | 294 |
29,151,436 | https://en.wikipedia.org/wiki/Megabias | A megabias, or a taphonomic megabias, is a large-scale pattern in the quality of the fossil record that affects paleobiologic analysis at provincial to global levels and at timescales usually exceeding ten million years. It can result from major shifts in intrinsic and extrinsic properties of organisms, including morphology and behaviour in relation to other organisms, or shifts in the global environment, which can cause secular or long-term cyclic changes in preservation.
Introduction
The fossil record exhibits bias at many different levels. At the most basic level, there is a global bias towards biomineralizing organisms, because biomineralized body parts are more resistant to decay and degradation. Due to the principle of uniformitarianism, there is a basic assumption in geology that the formation of rocks has occurred by the same naturalistic processes throughout history, and thus that the reach of such biases remains stable over time. A megabias is a direct contradiction of this, whereby changes occur in large scale paleobiologic patterns. This includes:
Changes in diversity and community structure over tens of millions of years
Variation in the quality of the fossil record between mass and background extinction times
Variation among different climate states, biogeographic provinces, and tectonic settings.
It is generally assumed that the quality of the fossil record decreases globally and across all taxa with increasing age, because more time is available for the diagenesis and destruction of both fossils and enclosing rocks, and thus the term "megabias" is usually used to refer to global trends in preservation. However, it has been noted that the fossil record of some taxa actually improves with greater age. Examples such as this, and other related paleobiological trends, clearly indicate the action of a megabias, but only within one particular taxon. Hence, it is necessary to define four classes of megabias related to the reach of the bias, first defined by Kowalewski and Flessa.
Within-taxon megabias
A change in the quality of a single taxon's record. It may happen whenever evolutionary, environmental, or geologic trends affect the taxon's fossilization potential.
Among-taxon static megabias
This occurs when the fossilization potential varies from group to group. Among-taxon megabiases include both static and dynamic distortions. A static megabias is constant through time. For example, flatworms have always had a poor record relative to mollusks because mollusks as a taxon are almost always biomineralizing, whereas flatworms are almost never biomineralizing.
Among-taxon dynamic megabias
A dynamic megabias occurs when the fossilization potential of one group relative to that of another group changes through time. For example, lingulide brachiopods had a lower fossilization potential than articulate brachiopods, but only in the early Paleozoic.
This has changed through time, governed by changes in bathymetry and lateral shifts in lithofacies associated with basin evolution. By the Middle Ordovician, articulates had diversified to become important components of all marine environments except the deep basin; inarticulates were most important in offshore and basinal settings. By moving away from the main taphonomic window, the inarticulates sacrificed their fossilization potential whilst not necessarily decreasing their biological diversity.
Global megabias
A global megabias is one that occurs over the whole world, though not necessarily in all depositional environments. There are numerous documented examples of this, many of which concern the Cambrian explosion and the Ediacaran fauna, both divisive subjects within the paleobiological community.
Cambrian reduction of phosphatization
Many fossils, such as the Cambrian Small Shelly Fauna (SSF), are preserved through secondary phosphatization. Such preservation can boost the diversity estimates in three ways:
By preserving fossils that might otherwise be destroyed
By preserving fine anatomical structures that enhance taxonomic resolution. Small anatomical details will show differences between two specimens that would otherwise be lumped within the same group; in this way, an inflated measure of diversity is given
By allowing easy collection. Phosphatized organisms are incredibly easily to extract by acid maceration, allowing large numbers of specimens to be collected with ease.
The number of phosphatic facies deposits decreases significantly from the early- to mid-Cambrian. Most probably, this is the cause for the pattern of SSF diversity decline after the Botomian extinction. Whilst there may well have been a significant extinction worldwide of small shelly fossils, a significant decrease in the abundance of phosphatized facies may have caused the decline in SF diversity to appear much more severe than it really was.
Overabundance of Konservat-Lagerstätten
It has been noted after the last 20 years that Exceptional Faunas, a particular class of Konservat-Lagerstätten exemplified by Burgess shale deposits, are statistically overabundant considering their age and style of preservation. This problem is also known as the "Post-Cambrian closure of the deep-water slope-basin taphonomic window". It seems that the cause of this may have been ecological, at least in the root cause; a post-Cambrian changes in the amount of bioturbation in deeper-water low oxygen environments increased sedimentary porosity and thus enhanced microbial activity and accelerated rates of decay. These higher rates of decay after the Cambrian meant that many soft bodied organisms were destroyed before the opportunity for preservation arose.
See also
Taphonomy
Notes
References
Paleobiology
Evolutionary biology | Megabias | Biology | 1,137 |
42,027,615 | https://en.wikipedia.org/wiki/SPG14 | Spastic paraplegia 14 (autosomal recessive) is a protein that in humans is encoded by the SPG14 gene.
References
Further reading
Proteins | SPG14 | Chemistry | 34 |
57,766,017 | https://en.wikipedia.org/wiki/DTaP-IPV%20vaccine | DTaP-IPV vaccine is a combination vaccine whose full generic name is diphtheria and tetanus toxoids and acellular pertussis adsorbed and inactivated poliovirus vaccine (IPV).
It is also known as DTaP/IPV, dTaP/IPV, DTPa-IPV, or DPT-IPV. It protects against the infectious diseases diphtheria, tetanus, pertussis, and poliomyelitis.
Branded formulations marketed in the USA are Kinrix from GlaxoSmithKline and Quadracel from Sanofi Pasteur.
Repevax is available in the UK.
In Japan, the formulation is called 四種混合(shishukongou - "mixture of 4").
Astellas markets it under the クアトロバック ('Quattro-back') formulation, while another is available from Mitsubishi Tanabe Pharma named テトラビック ('Tetrabic').
A previous product by Takeda Pharmaceutical Company has been withdrawn by the company.
References
Combination vaccines
Diphtheria
Whooping cough
Tetanus
Polio
Vaccines | DTaP-IPV vaccine | Biology | 249 |
41,701,469 | https://en.wikipedia.org/wiki/2go | 2go Interactive (Pty) Ltd is a South African company which operates a mobile social networking app. The company is based in Cape Town, South Africa.
History
2go was created in 2007 in Johannesburg, South Africa, by a group of University of Witwatersrand computer science students. The service was originally developed as a students-only mobile website intended to function as a communication tool for students. 2go eventually moved away from the students-only model and targeted developing markets in Africa such as Nigeria, Kenya, and Ghana.
By 2018, the app had lost most of its users with suggestions its failure to adapt to the growth of Android was to blame.
References
External links
Instant messaging clients
Mobile instant messaging clients
Android (operating system) software
BlackBerry software | 2go | Technology | 153 |
2,241,862 | https://en.wikipedia.org/wiki/Resinous%20glaze | Resinous glaze is an alcohol-based solution of various types of food-grade shellac. The shellac is derived from the raw material sticklac, which is a resin scraped from the branches of trees left from when the small insect, Kerria lacca (also known as Laccifer lacca), creates a hard, waterproof cocoon. When used in food and confections, it is also known as confectioner's glaze, pure food glaze, natural glaze, or confectioner's resin. When used on medicines, it is sometimes called pharmaceutical glaze.
Pharmaceutical glaze may contain 20–51% shellac in solution in ethyl alcohol (grain alcohol) that has not been denatured (denatured alcohol is poisonous), waxes, and titanium dioxide as an opacifying agent. Confectioner’s glaze used for candy contains roughly 35% shellac, while the remaining components are volatile organic compounds that evaporate after the glaze is applied.
Pharmaceutical glaze is used by the drug and nutritional supplement industry as a coating material for tablets and capsules. It serves to improve the product's appearance, extend shelf life and protect it from moisture, as well as provide a solid finishing film for pre-print coatings. It also serves to mask unpleasant odors and aid in the swallowing of the tablet.
The shellac coating is insoluble in stomach acid and may make the tablet difficult for the body to break down or assimilate. For this reason, it can also be used as an ingredient in time-released, sustained or delayed-action pills. The product is listed on the U.S. Food and Drug Administration's (FDA) inactive ingredient list.
Shellac is labeled as GRAS (generally recognized as safe) by the US FDA and is used as glaze for several types of foods, including some fruit, coffee beans, chewing gum, and candy. Examples of candies containing shellac include candy corn, Hershey's Whoppers and Milk Duds, Nestlé's Raisinets and Goobers, Tootsie Roll Industries's Junior Mints and Sugar Babies, Jelly Belly's jelly beans and Mint Cremes, Russell Stover's jelly beans, and several candies by Godiva Chocolatier and Gertrude Hawk. M&M's do not contain shellac.
A competing non-animal-based product is zein, a corn protein. It is preferred by some vegans because shellac production can kill many insects.
References
Pharmacy
Food additives | Resinous glaze | Chemistry | 538 |
56,104,174 | https://en.wikipedia.org/wiki/Leflutrozole | Leflutrozole (developmental code names BGS-649, CGP-47645) is an aromatase inhibitor which is under development by Mereo BioPharma and Novartis for the treatment of hypogonadism in men. It was also under investigation for the treatment of endometriosis, but development for this indication was discontinued. As of December 2017, leflutrozole is in phase II clinical trials for hypogonadism.
See also
List of investigational sex-hormonal agents § Estrogenics
References
External links
Leflutrozole - AdisInsight
Aromatase inhibitors
Experimental sex-hormone agents
Hormonal antineoplastic drugs
Nitriles
Organofluorides
Progonadotropins
Triazoles | Leflutrozole | Chemistry | 163 |
582,691 | https://en.wikipedia.org/wiki/Retraction%20in%20academic%20publishing | In academic publishing, a retraction is a mechanism by which a published paper in an academic journal is flagged for being seriously flawed to the extent that their results and conclusions can no longer be relied upon. Retracted articles are not removed from the published literature but marked as retracted. In some cases it may be necessary to remove an article from publication, such as when the article is clearly defamatory, violates personal privacy, is the subject of a court order, or might pose a serious health risk to the general public.
Procedure
A retraction may be initiated by the editors of a journal, or by the author(s) of the papers (or their institution). Retractions are typically accompanied by a retraction notice written by the editors or authors explaining the reason for the retraction. Such notices may also include a note from the authors with apologies for the previous error and/or expressions of gratitude to persons who disclosed the error to the author. Retractions must not be confused with small corrections in published articles.
There have been numerous examples of retracted scientific publications. Retraction Watch provides updates on new retractions, and discusses general issues in relation to retractions.
History
A 2011 paper in the Journal of Medical Ethics attempted to quantify retraction rates in PubMed over time to determine if the rate was increasing, even while taking into account the increased number of overall publications occurring each year. The author found that the rate of increase in retractions was greater than the rate of increase in publications. Moreover, the author notes the following:"It is particularly striking that the number of papers retracted for fraud increased more than sevenfold in the 6 years between 2004 and 2009. During the same period, the number of papers retracted for a scientific mistake did not even double..." (p. 251). Although the author suggests that his findings may indeed indicate a recent increase in scientific fraud, he also acknowledges other possibilities. For example, increased rates of fraud in recent years may simply indicate that journals are doing a better job of policing the scientific literature than they have in the past. Furthermore, because retractions occur for a very small percentage of overall publications (fewer than 1 in 1,000 articles), a few scientists who are willing to commit large amounts of fraud can highly impact retraction rates. For example, the author points out that Jan Hendrik Schön fabricated results in 15 retracted papers in the dataset he reviewed, all of which were retracted in 2002 and 2003, "so he alone was responsible for 56% of papers retracted for fraud in 2002—2003" (p 252).
During the COVID-19 pandemic, academia had seen a quick increase in fast-track peer-review articles dealing with SARS-CoV-2 problems. As a result, a number of papers have been retracted made "Retraction Tsunami" due to quality and/or data issues, leading many experts to ponder not just the quality of peer review but also standards of retraction practices.
Retracted studies may continue to be cited. This may happen in cases where scholars are unaware of the retraction, in particular when the retraction occurs long after the original publication.
The number of journal articles being retracted had risen from about 1,600 in 2013 to 10,000 in 2023. Most of the retractions in 2023 were contributed by Hindawi journals. The significant number of retractions involving Chinese co-authors—over 17,000 since 2021, including 8,000 from Hindawi journals—has led China to launch a nationwide audit addressing retractions and research misconduct.
Alternative versions of retraction
Retraction with replacement
A low percentage of retracted papers can be due to unintentional error within the author(s) work. Rather than removing the entire article, retraction with replacement has been a new practice to help authors avoid being seen as dishonest for mistakes that were not purposefully done. This method allows the author to fix their mistakes from the original paper, and submit an edited version to take the original paper’s place. The journal can decide to retract the original paper then upload the fixed version online, usually with a notice placed stating “Retraction and Replacement,” or “Correction,” on the article page. For example, JAMA will post the edited version with a retraction and replacement notice, along with a link to the original article, while Research Evaluation will use the term "correction" with a link posted on the updated article, referring to the old article.
Self-retraction
Self-retraction is a request from an author and/or co-authors to retract its own work from being published. Self-retraction by an author is recommended because once it gets retracted from the journal, then it can affect the author(s) because investigations can begin which will have an effect the author's reputation. If one retracts their own work on their terms, it would show more integrity and honesty as they are owning up to their own mistakes, just like the authors mentioned in The Wall Street Journal have done. Scientists at times have been asked to retract their work even though their work is exact and bold; the root cause of the problem should be looked into to avoid retractions. A system to distinguish papers from "good" and "bad" would be beneficial to researchers. This system may save the reputation of scientists and researchers. Most researchers publish honest work and sometimes simple mistakes happen to be overlooked by the peer review process. Retraction should not be for simple spelling errors, but for inaccurate, skewed, and fraudulent data. For example, today new technologies are being developed in a culture of transparency to align the opportunity to record false claims. Another solution is for researchers to use a term “self-citation” since citations look identical therefore they are classified in databases. Recommending a same database to evaluate the researchers own work can help lessen retractions.
Notable retractions
Retraction for error
2013 - Study on the Mediterranean diet published in New England Journal of Medicine and widely covered by media was retracted due to unreported non-random assignments. This was part of a larger effort verifying proper randomization in thousands of studies by anesthesiologist John Carlisle, who found problems in about 2% of those analyzed.
2012 - Séralini affair - Article suggesting reported an increase in tumors among rats fed genetically modified corn and the herbicide RoundUp retracted due to criticism of experimental design. According to the editor of the journal, a "more in-depth look at the raw data revealed that no definitive conclusions can be reached with this small sample size".
2003 Retracted Science article on ecstasy. See Retracted article on neurotoxicity of ecstasy.
Retraction for fraud or misconduct
2021 An article studying the open source community by Qiushi Wu and Kangjie Lu at the University of Minnesota was withdrawn after the Linux Foundation discovered that the researchers submitted patches for the Linux kernel with intentional bugs and without obtaining appropriate consent.
2020 On January 8, 2020, Russian journals retracted more than 800 articles after a large-scale investigation conducted by the Russian Academy of Sciences (RAS) following claims of unethical publications.
2018 On 11 April 2019, two articles on DNA damage by Abderrahmane Kaidi of the University of Bristol, one published in Science in 2010 and another in Nature in 2013, were retracted following evidence of data fabrication.
2017 Five articles in the field of consumer behavior and marketing research, by Brian Wansink at Cornell University, came under scrutiny after peers pointed out inconsistencies in the data. Wansink had written a blog post about asking a graduate student to "salvage" conclusions. Cornell University launched an investigation, which determined in 2018 that Wansink had committed academic misconduct. Wansink resigned. Wansink has since had 18 of his research papers retracted as similar issues were found in other publications.
2014 An article by Haruko Obokata et al. on STAP cells, a method of inducing a cell to become a stem cell, was proven to be falsified. Originally published in Nature, it was retracted later that year. It generated much controversy, and after an institutional investigation, one of the authors committed suicide.
2011 Eight journal articles authored by Duke University cancer researcher Anil Potti and others, which describe genomic signatures of cancer prognosis and predictors of response to cancer treatment, were retracted in 2011 and 2012. The retraction notices generally state that the results of the analyses described in the articles could not be reproduced. In November 2015, the Office of Research Integrity (ORI) found that Potti had engaged in research misconduct.
2010 A 1998 paper by Andrew Wakefield proposing that the MMR vaccine might cause autism, which was responsible for the MMR vaccine controversy, was retracted because "the claims in the original paper that children were "consecutively referred" and that investigations were "approved" by the local ethics committee have been proven to be false."
2009 Numerous papers written by Scott Reuben from 1996 to 2009 were retracted after it was discovered he never actually conducted any of the trials he claimed to have run.
2007 Retraction of several articles written by social psychologist Jennifer Lerner and colleagues from journals including Personality and Social Psychology Bulletin and Biological Psychiatry.
2006 Retraction of Patient-specific embryonic stem cells derived from human SCNT blastocysts, written by Hwang Woo-Suk. Fabrications in the field of stem cell research led to 'indictment on embezzlement and bioethics law violations linked to faked stem cell research'.
2003 Numerous articles with questionable data from physicist Jan Hendrik Schön were retracted from many journals, including both Science and Nature.
2002 Retraction of announced discovery of elements 116 and 118. See Livermorium, Victor Ninov.
1991 Thereza Imanishi-Kari, who worked with David Baltimore, published a 1986 article in the journal Cell on immunology, which showed unexpected results on how the immune system rearranges its genes to produce antibodies against antigens it encounters for the first time. Margot O'Toole, a postdoctoral researcher for Imanishi-Kari, claimed that she could not reproduce Imanishi-Kari's results and alleged that Imanishi-Kari had fabricated the data. After a major investigation, the paper was retracted when the National Institutes of Health concluded that data in the 1986 Imanishi-Kari article had been falsified. Five years later, in 1996, an expert panel appointed by the federal government found no evidence of scientific fraud and cleared Imanishi-Kari of misconduct, although the paper was not reinstated.
1982 John Darsee. Fabricated results in the Cardiac Research Laboratory of Eugene Braunwald at Harvard in the early 1980s. Initially thought to be brilliant by his boss. He was caught out by fellow researchers in the same laboratory.
Retraction for ethical violations
2019 An article by Wendy Rogers (Macquarie University, Australia) and colleagues on BMJ Open called for the mass retraction of more than 400 scientific papers on organ transplantation, amid fears the organs were obtained unethically from Chinese prisoners. Wendy Rogers said the journals, researchers and clinicians who used these studies were complicit in these methods of organ trafficking. According to the study, the transplant research community has failed to live up to the ethical standards for using organs from death row inmates that are still being published. These widespread unethical violations in research will cause many unpredictable consequences for science. In 2019, PLOS ONE also retracted 21 articles related to this incident.
2017 The journal Liver International retracted a Chinese study of liver transplantation because 564 livers grafted in the course of the research over 4 years could not be traced. The experts pointed out that it was implausible a hospital could have so many freely donated livers for transplantation, given the small number of donors in China at the time.
Retraction over data provenance
2020 On 22 May 2020, during the COVID-19 pandemic, an article was published in The Lancet which claimed to find evidence, based on a database of COVID-19 patients, that hydroxychloroquine and chloroquine increase the chance of patients dying in hospital as well as the chance of ventricular arrhythmia. Medical researchers and newspapers expressed suspicions about the validity of the data, provided by Surgisphere, which is founded by one of the authors of the study. The article was formally retracted by 4 June 2020, on request by the lead author Mandeep Mehra.
Retraction over public relations issues
2016 On March 4, 2016, an article in PLOS ONE about the functioning of the human hand was retracted due to outrage on social media over a reference to "Creator" inside the paper (#CreatorGate).
1896 Jose Rizal was said to have issued a letter of retraction regarding his novels and other published articles against the Roman Catholic Church, see José Rizal: Retraction controversy.
See also
Fabrication (science)
Post-publication peer review
Scientific misconduct
Sokal affair
Erratum
Correction (newspaper)
References
Further reading
Scientific misconduct
Academic publishing
Publishing
Error | Retraction in academic publishing | Technology | 2,713 |
48,259,292 | https://en.wikipedia.org/wiki/Questel%20Fort | Questel Fort () is a redoubt in Brest. It is a fortified structure of the Vauban type. It forms a closed square, with the main entry point placed on the least exposed side. This large quadrangle, 100 meters wide, is located between Fort Keranroux (1.5 km south) and Fort Penfeld (1 km to the North-east), and is also part of the same fortifications as Fort Montbarey.
The Fort du Questel monitors the valleys of the Moulin du Buis to prevent any enemies from becoming established and bombarding the city and harbor. Surrounded by deep moats and accessed by a drawbridge, it consists of a masonry wall (scarp), topped by a chemin de ronde, or covered path for musketeers. This path is itself dominated by an earthen rampart, angled to support artillery (26 guns total).
The garrison of about 200 men had access to various galleries, including two large ones underground that connect the central courtyard to the parapets. Note also the presence of toilet facilities, which at the time of Vauban were still a privilege. Built on a six-hectare site, the Fort du Questel dominates the valley of Allégoet, a tributary of the Penfeld. This site is now part of a set of refurbished natural spaces that lead to the banks of the Penfeld by a track passing in front of the Cavale Blanche hospital.
Onsite, the fortress offers walks through its sheltered green moat and its underground galleries, staircases, scarps and counterscarps, esplanade and fresh greenery nearby.
Gallery
References
Bibliography
Fortifications of Brest, France
Vauban fortifications in France
Fortifications articles needing attention to supporting materials
18th-century fortifications
Redoubts
Fortification lines
18th-century architecture in France | Questel Fort | Engineering | 375 |
5,155,088 | https://en.wikipedia.org/wiki/Dromasauria | "Dromasaurs" are an artificial grouping of small anomodont therapsids from the Middle and Late Permian of South Africa. They represent either a paraphyletic grade or a polyphyletic grouping of small non-dicynodont basal anomodonts rather than a clade, and as such are considered an invalid group today. "Dromasaurs" were historically united by their superficially similar appearances that were unlike other known anomodonts. They are all small in size with slender limbs and long tails, and have short skulls with very large eye sockets. "Dromasauria" (sometimes also known as "Dromasauroidea") traditionally includes three genera, all from the Karoo Supergroup of South Africa: Galepus, Galechirus, and Galeops. These genera have sometimes been divided into two subgroups, the monotypic family Galeopidae (containing only Galeops) and the Galechiridae for Galechiris and Galepus.
Despite their superficial similarities, "Dromasauria" is not recognised in modern cladistics-based taxonomy (where groups are based upon shared common ancestry). Rather than forming their own clade, phylogenetic analyses have found the various "dromasaurs" to be distributed individually throughout the evolutionary tree of basal anomodonts. In particular, Galeops is notably found to consistently be much closer to the dicynodonts than to the other "dromasaurs". Some earlier studies have inferred or even recovered a close sister-relationship between Galechirus and Galepus in a clade, to which the name Galechiridae has sometimes been applied. However, more recent phylogenetic analyses incorporating more data and more complete samples of basal anomodonts have found them at separate points on the tree too.
The cladogram below depicts the results of the phylogenetic analysis from Angielczyk and Kammerer (2017), with each of the three "dromasaurs" highlighted in light green:
See also
Evolution of mammals
Dicynodonts
References
Anomodonts
Taxa named by Robert Broom
Polyphyletic groups | Dromasauria | Biology | 444 |
4,169,860 | https://en.wikipedia.org/wiki/Rail%20integration%20system | A rail integration system (RIS; also called a rail accessory system (RAS), rail interface system, rail system, mount, base, gun rail, or simply a rail) is a generic term for any standardized attachment system for mounting firearm accessories via bar-like straight brackets (i.e. "rails") often with regularly spaced slots.
Rail systems are usually made of strips of metal or polymer screw-fastened onto the gun's receiver, handguard, or fore-end stock to allow variable-position attachments. An advantage of the multiple rail slots is the moveable positions to adjust for optimal placement of each item for a user's preferences, along with the ability to switch different items at different placements due to varying eye reliefs on gun sights. Firearm accessories commonly compatible with or intended for rail systems include tactical lights, laser sights, vertical forward grips, telescopic sights, holographic sights, reflex sights, backup iron sights, bipods/tripods, slings, and bayonets.
The common types of rail systems for firearms are the dovetail rail (including the Soviet variant known as the Warsaw Pact rail), the Weaver rail, the Picatinny rail, the SOPMOD, the KeyMod and the M-LOK. There are also various non-military designs used in shooting sports to attach slings and bipods such as the UIT rail, Zeiss rail and Freeland rail.
History
Original rails were a raised metal strip with the sides undercut, less standardized than the dovetail design, to allow hardware to slide on and be secured by means of compression only.
Design
Rail systems are usually based on the handguard of a weapon and/or the upper receiver. Modern pistols usually have rail systems on the underside of the barrel. Rails on rifles usually start at the top dead center ("12 o'clock"), with other common placements at the bottom 180° ("6 o'clock") and on the sides at 90° ("3 o'clock" and "9 o'clock"); some rails are also diagonal at 45° angles as opposed to 90° angles, though these are less common. There may be additional attachment rails or holes at each 45° angle position running partially or entirely the length of the handguard.
On the Kalashnikov rifles, the Warsaw rail is attached to the left side of the receiver when viewed from the rear. With more modern versions adding Picatinny style rails onto the sides of the handguards of the rifles for the mounting of additional equipment. Due to updating equipment, both styles may be found on some Warsaw Pact weapons.
Modern-designed firearms often include rails made into the body, instead of being an added-on modification. Older firearms may need permanent modifications of having holes drilled and tapped for screw threads to fasten the rail sections to the firearm. This is easier than milling out a dove tail slot for the placement of a gun sight's parts.
Optics such as telescopic sights, reflector sights, holographic sights, red dot magnifiers, night vision sights, or thermal sights may be placed between the iron sights. The rail section may also come in various heights to help align equipment, which may align with the original iron sights inline or below an illuminated optic's center dot, ring or chevron. This is referred to as absolute or lower 1/3 co-witness respectively.
In addition to height variations some rail brackets may be offset at various degrees. 22.5°, 45°, and 90° are the most common, to place accessories and/or backup folding collapsible iron sights in such a way so that they are out of the line sight on the top of the firearm and/or to decrease the outer profile edge's size. Then, the original sights are a backup if the electronic optic should fail. The rail section may also move weapon-mounted lights forward so the light does not shine and reflect on the firearm directly, which may create shadows.
The amount of rail space allows adjustment and personal optimization of each device and tool attached for the user. As designs have advanced the amount of space has succeeded in the actual need for placement space. Thus, rail covers and protectors may be added to prevent snagging on gear and/or plant foliage.
Future rails systems may have the option of carrying batteries or other electricity systems to supply the needs of the increasing electronics mounted to aid the shooter. Standards are still being determined for these types of systems. An example of such is NATO standards NATO Accessory Rail which is the continued improvement and standardization of the Picatinny rail.
Types
Most RIS equipment is compatible with one or more of the most common rail systems, all of which are broadly similar:
Dovetail rail: one of the earliest rail systems, relies primarily on friction from the side unit set screw on the mounted accessory to stop longitudinal shifting
Warsaw Pact rail: a Soviet-designed dovetail rail variant with cut-outs that allow quick side-mounting of optics (e.g. PSO-1 and USP-1) on Dragunov sniper rifles, RPG-7 and RPG-29 grenade launchers, as well as some versions of AKM and AK-74 assault rifles and PK family machine guns.
Weaver rail: an early improvement design upon the dovetail rail, invented by William Ralph Weaver (1905–1975). This system is still popular in the civilian market.
Picatinny rail: the mil-spec standardized rail system evolved from the Weaver rail. Also known as MIL-STD-1913, Picatinny rails date from the mid-1990s and have very strict dimensions and tolerance standards. The Picatinny has a rail of a very similar profile to the Weaver, but the slot width is 0.206 in (5.23 mm), and the spacing of slot centers is consistent at 0.394 in (10.01 mm). Many rail-grabber-mounted accessories can be used on either type of rail. The Picatinny locking slot width is and the spacing of slot centers is . Due to this, with devices that use only one locking slot, Weaver devices will fit on Picatinny rails, but Picatinny devices will not always fit on Weaver rails.
NATO Accessory Rail: a metric standardized upgrade from the Picatinny rail.
KeyMod: open source "negative space" (hollow slot) design introduced by VLTOR to replace the Picatinny rail for mounting accessories (except for scope mounts).
M-LOK: a free licensed "negative space" design introduced by Magpul Industries to compete with KeyMod.
These systems are used primarily in the military and by firearm enthusiasts to improve the usability of the weapon, being accessorized quickly and efficiently without requiring the operator to field-strip the weapon. Basic systems such as small rails (20mm is standard) with holes machined in them to be screwed onto the existing hand-guard of a rifle can cost as little as US $25 to US $40. More advanced systems allow for numerous accessories to be mounted simultaneously and can cost upwards of US $200.
Compatibility
Adapters to other types of rail interfaces may be used for legacy issues and/or to change the surface texture, abrasiveness and/or overall outer circumference of the entire rails system for the fit of the hand. Dovetail, Weaver, and Picatinny are all outward or raised attachment surfaces, while M-LOK and KeyMod have smooth surfaces with different standards & styles of holes cut into their assemblies to place the attachment hardware internally. Both of these styles are often in the handguards. All make the mounting and dismounting of these objects significantly easier.
Items may be fastened by threaded bolts, requiring the use of a screwdriver or Allen wrench. Some tool-free variations of thumb screws or thumb nuts may have a threaded quick disconnect lever that pulls the hardware and plates together against the rails. During firearm recoil, the accessory may slide within that section of the rail. To avoid this, when tightening a slide, move the device forward in the placement slots and ensure that the section of the bolt is positioned against the vertical/forward section of the rail slots.
Adoption
Though not particularly common on firearms until the late 20th century, most modern firearms in military service and the civilian market have rail integration systems that may replace original parts. The prevalence of rails on modern firearms compared to past designs is largely owed to the increasing popularity and availability of attachments such as sights.
The most common weapons to have rails are individual firearms, particularly long guns and service rifles such as the rifle, carbine, submachine gun, personal defense weapon, shotgun, designated marksman rifle, sniper rifle, and squad automatic weapon, though some larger or crew-served weapons such as the heavy machine gun, anti-materiel rifle, and rocket launcher have been designed or refreshed to include rails for compatibility. Even ranged weapons that are not firearms, such as bow and arrow, crossbow, airsoft gun, and paintball marker.
HMGs have started to include and use rail sections and options for attachments of optics. Civilian clone rifles are the main weapons to adopt this, while crossbows, hunting rifles, shotguns, and handguns may be produced with rail sections either attached and/or made structurally as part of the actual firearm. Airsoft and paintball clone weapons may also have rails.
See also
Sling (firearms)
Zeiss rail
Notes
References
Magpul Industries - M-LOK DESCRIPTION AND FAQ DOCUMENT
KeyMod vs. M-Lok: The Next AR Rail Standard by Chris Baker, November, 19, 2014
KeyMod vs. M-LOK Modular Rail System Comparison, Presented by Caleb McGee, Naval Special Warfare Center Crane Division, 4 May 2017 full pdf on page
M-LOK vs KeyMod comparison 2017 MLok and KeyMod Comparison 3 years later 2017
External links
KeyMod vs. M-LOK comparison
Firearm components
Mechanical standards | Rail integration system | Technology,Engineering | 2,050 |
30,980,081 | https://en.wikipedia.org/wiki/Ancilla%20bit | In reversible computing, ancilla bits are extra bits being used to implement irreversible logical operations. In classical computation, any memory bit can be turned on or off at will, requiring no prior knowledge or extra complexity. However, this is not the case in quantum computing or classical reversible computing. In these models of computing, all operations on computer memory must be reversible, and toggling a bit on or off would lose the information about the initial value of that bit. For this reason, in a quantum algorithm there is no way to deterministically put bits in a specific prescribed state unless one is given access to bits whose original state is known in advance. Such bits, whose values are known a priori, are known as ancilla bits in a quantum or reversible computing task.
A trivial use for ancilla bits is downgrading complicated quantum gates into simple gates. For example, by placing controls on ancilla bits, a Toffoli gate can be used as a controlled NOT gate or a NOT gate.
For classical reversible computation it is known that a constant number O(1) of ancilla bits is necessary and sufficient for universal computation. Additional ancilla bits are not necessary, but the extra workspace can allow for simpler circuit constructions that use fewer gates.
Ancilla qubits
The concept of ancilla bit can be extended for quantum computing in terms of ancilla qubits, that can be used for example in quantum error correction.
One notable example for the use of ancilla qubits in quantum computing is the Deutsch–Jozsa algorithm.
Quantum catalysis uses ancilla qubits to store entangled states that enable tasks that would not normally be possible with local operations and classical communication (LOCC).
References
Quantum information science | Ancilla bit | Physics | 383 |
27,395,553 | https://en.wikipedia.org/wiki/Bjerrum%20plot | A Bjerrum plot (named after Niels Bjerrum), sometimes also known as a Sillén diagram (after Lars Gunnar Sillén), or a Hägg diagram (after Gunnar Hägg) is a graph of the concentrations of the different species of a polyprotic acid in a solution, as a function of pH, when the solution is at equilibrium. Due to the many orders of magnitude spanned by the concentrations, they are commonly plotted on a logarithmic scale. Sometimes the ratios of the concentrations are plotted rather than the actual concentrations. Occasionally H+ and OH− are also plotted.
Most often, the carbonate system is plotted, where the polyprotic acid is carbonic acid (a diprotic acid), and the different species are dissolved carbon dioxide, carbonic acid, bicarbonate, and carbonate. In acidic conditions, the dominant form is ; in basic (alkaline) conditions, the dominant form is ; and in between, the dominant form is . At every pH, the concentration of carbonic acid is assumed to be negligible compared to the concentration of dissolved , and so is often omitted from Bjerrum plots. These plots are very helpful in solution chemistry and natural water chemistry. In the example given here, it illustrates the response of seawater pH and carbonate speciation due to the input of man-made emission by the fossil fuel combustion.
The Bjerrum plots for other polyprotic acids, including silicic, boric, sulfuric and phosphoric acids, are other commonly used examples.
Bjerrum plot equations for carbonate system
If carbon dioxide, carbonic acid, hydrogen ions, bicarbonate and carbonate are all dissolved in water, and at chemical equilibrium, their equilibrium concentrations are often assumed to be given by:
where the subscript 'eq' denotes that these are equilibrium concentrations, K1 is the equilibrium constant for the reaction + H+ + (i.e. the first acid dissociation constant for carbonic acid), K2 is the equilibrium constant for the reaction H+ + (i.e. the second acid dissociation constant for carbonic acid), and DIC is the (unchanging) total concentration of dissolved inorganic carbon in the system, i.e. [] + [] + []. K1, K2 and DIC each have units of a concentration, e.g. mol/L.
A Bjerrum plot is obtained by using these three equations to plot these three species against , for given K1, K2 and DIC. The fractions in these equations give the three species' relative proportions, and so if DIC is unknown, or the actual concentrations are unimportant, these proportions may be plotted instead.
These three equations show that the curves for and intersect at , and the curves for and intersect at . Therefore, the values of K1 and K2 that were used to create a given Bjerrum plot can easily be found from that plot, by reading off the concentrations at these points of intersection. An example with linear Y axis is shown in the accompanying graph. The values of K1 and K2, and therefore the curves in the Bjerrum plot, vary substantially with temperature and salinity.
Chemical and mathematical derivation of Bjerrum plot equations for carbonate system
Suppose that the reactions between carbon dioxide, hydrogen ions, bicarbonate and carbonate ions, all dissolved in water, are as follows:
Note that reaction is actually the combination of two elementary reactions:
+ H+ +
Assuming the mass action law applies to these two reactions, that water is abundant, and that the different chemical species are always well-mixed, their rate equations are
where denotes concentration, t is time, and K1 and k−1 are appropriate proportionality constants for reaction , called respectively the forwards and reverse rate constants for this reaction. (Similarly K2 and k−2 for reaction .)
, the concentrations are unchanging, hence the left hand sides of these equations are zero. Then, from the first of these four equations, the ratio of reaction 's rate constants equals the ratio of its equilibrium concentrations, and this ratio, called K1, is called the equilibrium constant for reaction , i.e.
where the subscript 'eq' denotes that these are equilibrium concentrations.
Similarly, from the fourth equation for the equilibrium constant K2 for reaction ,
Rearranging gives
and rearranging , then substituting in , gives
The total concentration of dissolved inorganic carbon in the system is given by substituting in and :
Re-arranging this gives the equation for :
The equations for and are obtained by substituting this into and .
See also
Charlot equation
Gran plot (also known as Gran titration or the Gran method)
Henderson–Hasselbalch equation
Hill equation (biochemistry)
Ion speciation
Fresh water
Seawater
Thermohaline circulation
References
Acid–base chemistry
Aquatic ecology
Chemical oceanography
Geochemistry
Limnology
Oceanography
Soil chemistry
Thermodynamics
Water chemistry | Bjerrum plot | Physics,Chemistry,Mathematics,Biology,Environmental_science | 1,028 |
56,223,208 | https://en.wikipedia.org/wiki/Ozarkcollenia | Ozarkcollenia is an extinct genus of stromatolite-making cyanobacteria from Missouri, United States. It was related to Collenia. Ozarkcollenia may have formed in a lake of volcanic origin. The fossils of Ozarkcollenia laminata have been dated to the Proterozoic eon, about 1.5 billion years ago. It occurs in parts of Missouri's Ozark Mountains.
References
†Ozarkcollenia
Stromatolites
Prehistoric bacteria | Ozarkcollenia | Biology | 105 |
3,015,678 | https://en.wikipedia.org/wiki/Kent%20%28cigarette%29 | Kent is an American brand of cigarettes, currently owned and manufactured by R.J. Reynolds Tobacco Company in the United States and British American Tobacco elsewhere. The brand is named after Herbert Kent, a former executive at Lorillard Tobacco Company.
History
Widely recognized by many as the first popular filtered cigarette, Kent was introduced by the Lorillard Tobacco Company in 1952 around the same time a series of articles entitled "cancer by the carton", published by Reader's Digest, scared American consumers into seeking out a filter brand at a time when most brands were filterless. (Viceroy cigarettes had been the first to introduce filters, in 1936.)
Kent widely touted its "famous micronite filter" and promised consumers the "greatest health protection in history". Sales of Kent skyrocketed, and it has been estimated that in Kent's first four years on the market, Lorillard sold some 13 billion Kent cigarettes.
From March 1952 until at least May 1956, however, the Micronite filter in Kent cigarettes contained compressed blue asbestos within the crimped crepe paper, which is the most carcinogenic type of asbestos. It has been suspected that many cases of mesothelioma have been caused specifically by smoking the original Kent cigarettes, and various lawsuits followed over the years because of it. Lorillard quietly changed the filter material from asbestos to the more common cellulose acetate in mid-1956. Kent continued to grow until the late 1960s, then began a long, steady decline as more filtered cigarette brands promising even lower tar (and appealing to smokers' desires for a "safer" smoke) were introduced.
Kent Cigarettes sponsored The Dick Van Dyke Show during its second season, and actor Dick Van Dyke filmed many spots smoking them, along with Rose Marie and Morey Amsterdam. The cigarettes were touted as being packaged in a "crush proof box".
However, Kent continued to stay in the top ten cigarette brand list until 1979. While continuing domestic sale and production, Lorillard sold the overseas rights of Kent and all of its other brands in 1977, and today Kents manufactured outside the U.S. are property of British American Tobacco. It eventually became one of their most popular brands, along with Dunhill, Lucky Strike, Pall Mall, and Rothmans.
On June 15, 2014, Reynolds American offered to buy the Lorillard tobacco company for $27.4 billion and effective June 12, 2015, the Kent brand became the property of R. J. Reynolds Tobacco Company.
Various advertising posters were made for Kent cigarettes, ranging from 1955 until 1986. One particular series of ads implied that smoking and eating were synonymous — in both pleasure and necessity.
Kent in Romania
Between 1970 and 1990 Kent was the most sought after cigarette in Romania and in some parts of the domestic market used as payment or bribe. In the latter part of this era, Kent was no longer available in regular retail, being sold officially only in hard currency shops. Obviously, the black market was thriving at the time, as most Kents were being smuggled in by those relatively few Romanians who were allowed to travel abroad (sea and air crew, diplomatic staff, etc.) The 2004 debut short film () by Cristi Puiu is titled after the bribes discussed in the film.
Markets
Kent is or was sold in the following countries: Jordan, Belgium, Brazil, Republic of Ireland, United Kingdom, Norway, Sweden, Finland, Estonia, Luxembourg, Netherlands, Greece, Switzerland, Austria, Spain, Italy, Poland, Romania, Israel, Moldova, Czech Republic, Croatia, Iraq, Albania, Latvia, Lithuania, Belarus, Ukraine, Russia, Azerbaijan, Georgia, Kazakhstan, Uzbekistan, Egypt, South Africa, Syria, Iran, United States, Kosovo, Mexico, El Salvador, Chile, Turkey, Peru, Brazil, Paraguay, Argentina, Vietnam, Australia, Singapore, Mongolia, China, Saudi Arabia, Hong Kong, Lebanon, Japan and South Korea.
See also
Tobacco smoking
References
1952 establishments in the United States
Asbestos disasters
Asbestos
British American Tobacco brands
Products introduced in 1952
R. J. Reynolds Tobacco Company brands
Socialist Republic of Romania | Kent (cigarette) | Environmental_science | 842 |
45,031,048 | https://en.wikipedia.org/wiki/Apache%20Mesos | Apache Mesos is an open-source project to manage computer clusters. It was developed at the University of California, Berkeley.
History
Mesos began as a research project in the UC Berkeley RAD Lab by then PhD students Benjamin Hindman, Andy Konwinski, and Matei Zaharia, as well as professor Ion Stoica. The students started working on the project as part of a course taught by David Culler. It was originally named Nexus but due to a conflict with another university's project, was renamed to Mesos.
Mesos was first presented in 2009 (while still named Nexus) by Andy Konwinski at HotCloud '09 in a talk accompanying the first paper published about the project. Later in 2011 it was presented in a more mature state in a talk by Zaharia at the Usenix Symposium on Networked Systems Design and Implementation conference about the paper "Mesos: A Platform for Fine-Grained Resource Sharing in the Data Center" by Benjamin Hindman, Andy Konwinski, Zaharia, Ali Ghodsi, Anthony D. Joseph, Randy Katz, Scott Shenker, Ion Stoica.
On July 27, 2016, the Apache Software Foundation announced version 1. It added the ability to centrally supply Docker, rkt and appc instances.
On April 5, 2021, it was voted to move Mesos to the Apache Attic, however the vote was cancelled two days later due to increased interest.
Technology
Mesos uses Linux cgroups to provide isolation for CPU, memory, I/O and file system.
Mesos is comparable to Google's Borg scheduler, a platform used internally to manage and distribute Google's services.
Apache Aurora
Apache Aurora is a Mesos framework for both long-running services and cron jobs, originally developed by Twitter starting in 2010 and open sourced in late 2013. It can scale to tens of thousands of servers, and holds many similarities to Borg including its rich domain-specific language (DSL) for configuring services. As of February 2020 the project was retired to the Attic. A fork of the project was maintained by former members, hosted on GitHub under the name Aurora Scheduler.
Chronos
Chronos is a distributed cron-like system which is elastic and capable of expressing dependencies between jobs.
Marathon
Marathon is promoted for platform as a service or container orchestration system scaling to thousands of physical servers. It is fully REST-based and allows canary-style deployments and deployment topologies. It is written in the programming language Scala.
Users
The social networking site Twitter began using Mesos and Apache Aurora in 2010, after Hindman gave a presentation to a group of Twitter engineers.
Airbnb said in July 2013 that it uses Mesos to run data processing systems like Apache Hadoop and Apache Spark.
The Internet auction website eBay stated in April 2014 that it used Mesos to run continuous integration on a per-developer basis. They accomplish this by using a custom Mesos plugin that allows developers to launch their own private Jenkins instance.
In April 2015, it was announced that Apple service Siri is using its own Mesos framework called Jarvis.
In August 2015, it was announced that Verizon selected Mesosphere's DC/OS, which is based on open source Apache Mesos, for data center service orchestration.
In November 2015, Yelp announced they had been using Mesos and Marathon for a year and a half for production services.
Commercial support
Software startup Mesosphere, Inc. sells the Datacenter Operating System, a distributed operating system, based on Apache Mesos. In September 2015, Microsoft announced a commercial partnership with Mesosphere to build container scheduling and orchestration services for Microsoft Azure. In October 2015, Oracle announced support for Mesos through Oracle Container Cloud Service.
See also
Dominant resource fairness - the resource-sharing policy used in Mesos.
List of cluster management software
Comparison of cluster software
References
External links
Mesos
Mesos
Cloud infrastructure
Free software for cloud computing
Linux containerization
Software using the Apache license | Apache Mesos | Technology | 835 |
54,594,340 | https://en.wikipedia.org/wiki/NGC%207075 | NGC 7075 is an elliptical galaxy located about 290 million light-years away in the constellation of Grus. NGC 7075 was discovered by astronomer John Herschel on September 4, 1834. It is classfied a radio galaxy.
NGC 7075 contains a Fanaroff-Riley class I radio source called PKS 2128-388. It has an unresolved core component. Its eastern radio jet, is found to have faint emission which extends out by ≈1.9 kpc from its nucleus. A CO disc is found in NGC 7075 but unresolved. According to Atacama Large Millimeter Array observations, a hole is present in the gas distribution, indicating gas disc disturbance.
IC 5105 Group
According to A. M. Garcia, NGC 7075 is part of the IC 5105 group (also known as LGG 445). This group of galaxies contains at least 19 members. The other galaxies in the group are: NGC 7057, NGC 7060, NGC 7072, NGC 7087, NGC 7110, NGC 7130, IC 5105, IC 5105A, IC 5128, IC 5139, and eight galaxies in the ESO catalogue.
See also
List of NGC objects (7001–7840)
Radio galaxy
M87
NGC 7016
References
External links
Elliptical galaxies
Radio galaxies
Grus (constellation)
7075
66895
Astronomical objects discovered in 1834 | NGC 7075 | Astronomy | 291 |
9,936,271 | https://en.wikipedia.org/wiki/Joint%20Precision%20Airdrop%20System | The Joint Precision Airdrop System (JPADS) is an American military airdrop system which uses the Global Positioning System (GPS), steerable parachutes, and an onboard computer to steer loads to a designated point of impact (PI) on a drop zone (DZ). The JPADS family of systems consists of several precision airdrop systems, ranging from extra light to heavy payloads. JPADS is used in conjunction with mission planning software that resides on a laptop. The function of this mission planning software includes computing release points, weather forecasting, acquiring measurements of wind velocity, altitude, air pressure, and temperature. It can also receive weather updates and en route mission changes through satellite links.
History
U.S. Army Research, Development and Engineering Command (RDECOM) was the primary developer for JPADS, which meets several requirements: increased ground accuracy, standoff delivery, increased air carrier survivability, and improved effectiveness/assessment feedback regarding airdrop mission operations. The U.S. Army and U.S. Air Force began jointly developing this system in 1993. The U.S. Air Force made its first operational/combat use of the system in Afghanistan in 2006.
Operation
The steerable parachute or parafoil is called a "decelerator," and gives the JPADS system directional control throughout its descent by means of decelerator steering lines attached to the Autonomous Guidance Unit (AGU). They create drag on either side of the decelerator, which turns the parachute, thus achieving directional control.
The AGU contains a GPS, a battery pack, and the guidance, navigation and control (GN&C) software package. It also houses the hardware required to operate the steering lines. The AGU obtains its position prior to exiting the aircraft, and continues to calculate its position via the GPS throughout descent.
The Mission Planner software gives the aircrew the ability to plan the mission, in flight if necessary, as well as steer the aircraft to its Computed Air Release Point (CARP), where the load is released.
Increments
JPADS involves four increments, categorized by the weight of the cargo to be dropped:
Increment I: JPADS-2K / applies to loads up to 2,200 lb / classified as the “extra light” category / commensurate with Container Delivery System (CDS) bundles.
Increment II: JPADS-10K / applies to loads up to 10,000 lb.
Increment III: JPADS-30K / applies to loads up to 30,000 lb.
Increment IV: JPADS-60K / applies to loads up to 60,000 lb.
Accuracy
JPADS is reported to be accurate to , drastically reduces drop zone size requirements; significantly increasing the number of locations which can be used as a drop zone. This reduces both the risk of hostile fire to aircraft and aircrews and the amount of cargo that misses a drop zone.
Benefits
JPADS offers several main benefits, including an increase in the number of available drop zones and an increase in the cargo's precision, which benefits the user. JPADS also increases the survivability of the delivery aircraft and its crew.
Ground Accuracy
Current drop zones are quite large; or more. Airdropping sequential loads (multiple loads aboard a single aircraft) requires very long drop zones on the order of or more, or else the aircraft must make multiple passes over the same area, a tactically unsound thing to do. Furthermore, achieving a high degree of accuracy (less than ) requires the aircraft to fly at the lowest altitude possible, which can range from above ground level to as high as , depending on the altitude of the drop zone, the weight of the load, and the number and type of parachutes required.
JPADs can achieve the same or better accuracy from greater heights, allowing the aircraft to drop the load at a much higher, and usually safer, altitude.
Standoff Delivery
Because JPADS allows the aircraft to drop at high-altitude, the aircraft can actually drop the load a good distance away from the drop zone, which affords the aircrew to remain free of enemy threats which may be near the area where the load is being dropped.
Survivability
Airdrops are usually performed at slow speeds for an aircraft, usually 130 kts for paratroopers and 140 kts for cargo. When combined with the low altitude required for precision, the aircraft are vulnerable to enemy ground fire. With JPADS, the aircraft is much more likely to survive, as it can drop at a much higher altitude, above most enemy ground fire.
Feedback
Because the system can transmit its current position back to the airdrop aircraft, it provides its exact landing location which the aircrew can then transmit to ground forces which may not have arrived at the drop zone.
See also
Delivery drone
Loadmaster
Pathfinder (military)
Airborne forces
Paratrooper
Static line
High-altitude military parachuting
References
External links
Airborne Systems' JPADS
Sherpa JPADS System Overview
Sherpa JPADS System Overview
Global Security - JPADS
US Army's NATICK article on JPADS
Defense Industry Daily article on JPADS
HAHO/HALO for Parachutists
Defenselink article with photo
Defense Update - JPADS The Way Ahead
DragonFly JPADS 10K enters full-rate production
How the US pulled off its humanitarian aid missions to the Yazidis
Combat support and combat service support - Army
Natick makes resupply from sky possible
Air freight
American military aviation
Global Positioning System | Joint Precision Airdrop System | Technology,Engineering | 1,128 |
17,770,902 | https://en.wikipedia.org/wiki/Gaiola%20%28construction%29 | A gaiola pombalina (Pombaline cage; ) is a masonry building reinforced with an internal wooden cage, developed as an anti-seismic construction system in Portugal after the 1755 Lisbon earthquake and implemented during the reconstruction of Lisbon Baixa (Lisbon downtown).
Background
The catastrophic event of 1755 showed the fragility of the masonry construction, which is not able to absorb and dissipate the energy released by the earthquake. Downtown Lisbon was heavily damaged and, in anticipation of similar catastrophe, a new construction method was developed. The entire downtown was razed to make way for a rebuilding initiative, which was centered on the gaiola pombalina system. The term gaiola meant "cage" and was named after the Sebastião José de Carvalho e Melo, the first Marquis of Pombal. He was the Portuguese minister who introduced the building method.
Features of the old buildings that survived were retained while those that did not were replaced. There are sources that cite the construction methods in shipbuilding as the inspiration of the three-dimensional wooden structure. Wood, being deformable, resists the forces of tension and compression that occur during an earthquake.
Features
Masonry is more effective than wood in resisting fires. Therefore, incorporating a wooden structure in masonry walls combined the advantages of both types of construction. The gaiola pombalina building features a traditional timber flooring and a hybrid timber-masonry shear walls. The walls were constructed using a wooden truss system that was filled with masonry in the empty areas.
The gaiola pombalina system was also adopted by other European cities. There is the case of the palace built according to the concept of gaiola in the town of Filogaso in the Calabria region. It was the only remaining building after the town was completely destroyed by an earthquake in 1783.
See also
Pombaline style
References
Buildings and structures by construction material
Earthquake engineering | Gaiola (construction) | Engineering | 390 |
6,197,083 | https://en.wikipedia.org/wiki/Ballie | Ballie is an upcoming AI robot created by Samsung. It is an autonomous robot which has the ability to control smart home devices.
History
It was first unveiled at Samsung's CES event in CES 2020, and later updated the design in CES 2024.
Design
References
Social robots
Robotics
Robots | Ballie | Physics,Technology,Engineering | 62 |
10,403,211 | https://en.wikipedia.org/wiki/Case%20%28goods%29 | A case of some merchandise is a collection of items packaged together. A case is not a strict unit of measure. For consumer foodstuff such as canned goods, soda, cereal, and such, a case is typically 24 items, however cases may consist of any quantity depending on manufacturer packaging - cases are typically found in multiples of 4 or 6. For larger bottles such as gallon jugs, a case is typically 4.
Examples
The standard case for bottles of soda and Powerade contains 15 bottles due to their peculiar shape and size.
Cases of video tape are typically packed 10 to a case.
A case of wine contains 12 bottles of each.
Book manufacture
The term case binding in the book manufacturing industry refers to a collection of pages contained in a case which is attached to it. (There are also cases for books e.g. slipcases which merely enclose a book.) The original case is often now called simply the binding, although the integrated manufacturing process still uses the term case to refer to the hard cover and spine.
See also
Box
Carton
Crate
Packaging
Fast-moving consumer goods
References
Sources
Yam, K.L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009,
Goods (economics)
Containers | Case (goods) | Physics | 253 |
41,015,136 | https://en.wikipedia.org/wiki/Self-anointing%20in%20animals | Self-anointing in animals, sometimes called anointing or anting, is a behaviour whereby a non-human animal smears odoriferous substances over themselves. These substances are often the secretions, parts, or entire bodies of other animals or plants. The animal may chew these substances and then spread the resulting saliva mixture over their body, or they may apply the source of the odour directly with an appendage, tool or by rubbing their body on the source.
The functions of self-anointing differ between species, but it may act as self-medication, repel parasites, provide camouflage, aid in communication, or make the animal poisonous.
Primates
Several primate species self-anoint with various items such as millipedes, leaves and fruit. They sometimes drool while doing this. Both capuchin monkeys and squirrel monkeys perform urine washing, when they deposit a small quantity of urine onto the palm of a hand and then rub it on the sole of the opposite foot. It is thought to have multiple functions including hygiene, thermoregulation and response to irritation from biting ectoparasites (such as ticks and botfly). Some strepsirrhines and New World monkeys also self-anoint the body with urine to communicate.
Capuchins
Wild wedge-capped capuchin monkeys (Cebus olivaceus) self-anoint with millipedes (Orthoporus dorsovittatus). Chemical analysis revealed these millipedes secrete two benzoquinones, compounds known to be potently repellent to insects and the secretions are thought to provide protection against insects, particularly mosquitoes (and the bot flies they transmit) during the rainy season. Millipede secretion is so avidly sought by the monkeys that up to four of them will share a single millipede. The anointment must also involve risks, since benzoquinones are toxic and carcinogenic; however, it is likely that for capuchins, the immediate benefits of self-anointment outweigh the long-term costs. Secretions from these millipedes also elicit self-anointing in captive male and female tufted capuchin (C. apella) and white-faced capuchin (C. capucinus) monkeys.
Wild Cebus anoint more with plant parts, including fruits, whereas wild Sapajus anoint more with ants and other arthropods. White-faced capuchins in particular use more plant species at each site for anointing compared with other capuchins and may specialize in anointing as an activity independent from foraging, whereas most other capuchin species tend to eat the substances they use for anointing. Wild Cebus anoint at a higher frequency than Sapajus as occurs in captive groups. However, contrary data from captive animals there no difference in the range of sociality for anointing between Cebus and Sapajus in the wild.
Capuchin monkeys at the Edinburgh Zoo rub onions and limes on their skin and into their fur as an antiseptic and insect repellent.
White-faced capuchin monkeys sometimes anoint their bodies with mud and plant matter, a natural insect repellent. With their heads and faces slathered in this mixture, these highly social primates lose their ability to recognise each other and previously friendly monkeys can become fighting foes.
Spider monkeys
Mexican spider monkeys (Ateles geoffroyi) self-anoint with the leaves of three species of plants;
the Alamos pea tree (Brongniartia alamosana), the trumpet tree (Cecropia obtusifolia) and wild celery (Apium graveolens). In one study, only two males in a group of 10 individuals displayed self-anointing. Only the sternal and axillary regions of the body were rubbed with the mix of saliva and plant material. There was a lack of correlation between the occurrence of self-anointing and time of day, season of the year, ambient temperature or humidity, indicating that this behaviour does not function in repelling insects and/or mitigating topical skin infections in this species. Rather, the three plant species spread an intensive and aromatic odour when crushed, indicating that self-anointing in Mexican spider monkeys may play a role in the context of social communication, possibly for signalling of social status or to increase sexual attractiveness.
Lemurs
Male ring-tailed lemurs have scent glands on their wrists, chests, and in the genital area. During encounters with rival males they may perform ritualised aggression by having a "stink fight". The males anoint their tails by rubbing the ends of their tails on the inside of their wrists and on their chests. They then arch their tails over their bodies and wave them at their opponent. The male toward which this is directed either responds with a display of his own, physical aggression, or flees. "Stink fights" can last from 10 minutes to one hour.
Black lemurs have also been observed self-anointing with millipedes.
Ungulates
Several ungulates self-anoint by spraying urine onto their own bodies or onto the ground or into a wallow before rubbing themselves onto the substrate.
In Nile lechwe, a unique form of marking is seen with the start of mating. The male bends his head to the ground and urinates on his throat and cheek hair. He then rubs his dripping beard on the female's forehead and rump.
Deer
Unlike other deer species, chital do not spray urine on their bodies. Instead, male chital mark their territory by dripping urine in scrapes, and then pawing them.
Sambar stags will wallow and dig their antlers in urine soaked soil and then rub against tree trunks. A stag will also mark himself by spraying urine directly in the face with a highly mobile penis, which is often erect during rutting activities. Similar urine-spraying behavior is common in other deer species, and is known as automarking.
Throughout the year white-tailed deer will rub-urinate, a process during which a deer squats while urinating so that urine will run down the insides of the deer's legs, over the tarsal glands, and onto the hair covering these glands. Bucks rub-urinate more frequently during the breeding season.
Elk
Bull elk often dig holes in the ground, in which they urinate and roll their body. The urine soaks into their hair and gives them a distinct smell which attracts cows. Some deer species, including elk, can mark themselves by spraying urine on their bodies from an erect penis. One type of scent-marking behavior in elk is known as "thrash-urination, which typically involves palpitation of the erect penis. A male elk's urethra points upward so that urine is sprayed almost at a right angle to the penis.
When urine marking, the male elk advertises this with a specialised vocalisation called the "bugle". During the last phase of the bugle, the bull rubs (palpates) his belly in rhythm with "yelps". He then directs a spray of urine towards his stomach or the ground. The hair on his stomach in front of the penis becomes soaked with urine and gains a dark brown tint.
Urine spraying is a variable behaviour. It may consist of simply dribbling a few drops of urine, or, large rhythmic discharges from an erect penis. A stream may be aimed at the mane on the neck, or, a fine mist might be sprayed against the stomach. The bull usually rub/palpates during this process. The urine can be voided almost at right angles to the erect penis. When a large volume of urine is sprayed, it usually takes place at a wallow. When urine spraying, the bull lowers his head towards the ground. In this position, his mane becomes soaked as he sprays urine forwards, between his legs. Once the wallow has been created, the male elk lowers himself into the area, rolls on his side and rub his mane on the soaked area of the wallow. He rubs the side of his face, his chest, stomach, legs, and flanks, which all become caked with mud. During wallowing, the elk's penis may remain erect and he may continue to spray urine.
Red deer
Male red deer anoint their wallows with urine and roll in these in a very similar way to elk.
Goats
Male goats self-anoint with their urine. This is done by extending the penis, bending the haunches and
extending the head backwards causing the urine to hit the mouth, throat, face and beard. This type of urination is possibly an indicator of rank and physical condition, and plays an important role in goat reproduction.
Rodents
The rice-field rat (Rattus rattoides) displays self-anointing behaviour in response to the anal-gland secretions of the weasel Mustela sibirica; however, they do not respond to the faeces and urine of the red fox (Vulpes vulpes). Juvenile rats born in the laboratory with no experience of weasels also display self-anointing behaviour. In this species, the self-anointing behaviour is not sex-specific or age-specific.
Ground squirrels chew rattlesnake skins and then lick their fur, a behaviour likely to deter that particular predator.
Hedgehogs
European hedgehogs (Erinaceus europaeus) have been widely reported to self-anoint with a range of toxic and irritating substances, particularly when introduced to a new or strong-smelling substance. These substances include toad skin, tobacco, soap and faecal matter. The hedgehog chews and licks at these substances when it encounters them which produces frothy saliva-substance mix that the hedgehog then spreads onto its spines.
Young hedgehogs will react to these substances and sometimes also lick substances on the spines of their mothers and self-anoint. Self-anointing has been observed in hedgehogs as young as 15 days of age, before their eyes open.
In one study, indications of self-anointing were observed in more than 11% of all observations. First-year, independent young self-anointed more than adults, and male hedgehogs had more indications of self-anointing than females. Self-anointing in adults displayed a peak in the summer, while no clear pattern was observed for young. It was concluded that self-anointing is dependent on gender, age and season.
Various hypotheses have been proposed to explain the function of self-anointing in hedgehogs. It may function as a form of scent camouflage, to mask their own scent with the new scent in the environment. Hedgehogs are resistant to many toxins and one theory is that hedgehogs spread toxins on their quills as added protection. Hedgehogs will sometimes kill toads (Bufo), bite into the toads' poison glands and smear the toxic mixture on their spines.
Canines
Several canines self-anoint. In these species, it is sometimes known as scent rolling.
Domestic dogs
Domestic dogs often roll in odoriferous substances, choosing items such as cow manure, a road kill, or rotten fish.
Wolves
Captive wolves will scent roll in a wide range of substances including animal feces, carrion (elk, mouse, pig, badger), mint extract, perfume, animal repellant, fly repellent, etc.
Bears
North American brown bears (Ursus arctos) make a paste of Osha roots (Ligusticum porteri) and saliva and rub it through their fur to repel insects or soothe bites. This plant, locally known as bear root, contains 105 active compounds, such as coumarins that may repel insects when topically applied. Navajo Indians are said to have learned to use this root medicinally from the bear for treating stomach aches and infections.
Birds
The use of millipedes in self-anointing by birds has been reported for the strong-billed woodcreeper (Xiphocolaptes promeropirhyncus) in Belize, the little shrike-thrush (Colluricincla megarhyncha parvula) in Australia, the black-throated shrikebill (Clytorhynchus nigrogularis) and the jungle mynah (Acridotheres fuscus) in the Fiji Islands, the European robin (Erithacus rubecula) in England and the grey-winged trumpeter (Psophia crepitans) and the pale-winged trumpeter (P. leucoptera) in northern South America.
In one study, mothballs (which contain naphthalene) were placed in a flowerbed. A common grackle picked one out, extended its left wing and rubbed the mothball up and down the length of the shaft of each of the secondary feathers. The grackle went on to rub the mothball over its secondary coverts on the ventral side and onto the propatagium area. The grackle then repeated the same rubbing actions on its right wing. The entire rubbing behaviour lasted approximately 10 minutes. European starlings also performed a similar behaviour with mothballs.
During anting, birds rub insects on their feathers, usually ants, which secrete liquids containing chemicals such as formic acid. These can act as an insecticide, miticide, fungicide, bactericide, or to make the insects edible by removing the distasteful acid. It possibly also supplements the bird's own preen oil. Although it has been suggested that anting acts as a way of reducing feather parasites such as mites or in controlling fungi or bacteria, there has been little convincing support for any of the theories. Some cases of anting involved the use of millipedes or puss moth caterpillars, and these too are known to release powerful defensive chemicals.
Another suggested function, based on observation of blue jays, is that the bird makes the insects edible, by discharging the harmful acid onto their feathers. The birds were found to show anting behaviour only if the ants had a full acid sac, and with subjects whose acid sacs had been experimentally removed, the behaviour was absent.
Finally, it has also been suggested that anting is related to feather moulting. The metabolic products of the ants may soothe skin irritated by unusually rapid feather replacement. However, the correlation may also be attributed to the greater activity of ants in summer.
Related behaviours
Some birds like antbirds and flickers not only wear ants, but also consume the ants as an important part of their diet. Other opportunist ant-eating birds include sparrows, wrens, grouse and starlings.
Social anointing
Owl monkeys (Aotus spp.) will anoint each other in groups of two or more by rubbing their bodies against one another while self-anointing with millipedes. Social anointing has been observed anecdotally in a captive colony for almost ten years. In 24, 5-min presentations to this group, a total of 25 separate bouts of social anointing were observed. Twenty-four of 35 owl monkeys were observed to socially anoint, including all ages and both sexes, in bouts which ranged from 5–322 seconds.
See also
Ring-tailed lemur#Olfactory communication
Personal grooming
References
External links
Video of self-anointing male elk
Animal communication
Ethology
Articles containing video clips | Self-anointing in animals | Biology | 3,225 |
207,560 | https://en.wikipedia.org/wiki/Photometry%20%28astronomy%29 | In astronomy, photometry, from Greek photo- ("light") and -metry ("measure"), is a technique used in astronomy that is concerned with measuring the flux or intensity of light radiated by astronomical objects. This light is measured through a telescope using a photometer, often made using electronic devices such as a CCD photometer or a photoelectric photometer that converts light into an electric current by the photoelectric effect. When calibrated against standard stars (or other light sources) of known intensity and colour, photometers can measure the brightness or apparent magnitude of celestial objects.
The methods used to perform photometry depend on the wavelength region under study. At its most basic, photometry is conducted by gathering light and passing it through specialized photometric optical bandpass filters, and then capturing and recording the light energy with a photosensitive instrument. Standard sets of passbands (called a photometric system) are defined to allow accurate comparison of observations. A more advanced technique is spectrophotometry that is measured with a spectrophotometer and observes both the amount of radiation and its detailed spectral distribution.
Photometry is also used in the observation of variable stars, by various techniques such as, differential photometry that simultaneously measures the brightness of a target object and nearby stars in the starfield or relative photometry by comparing the brightness of the target object to stars with known fixed magnitudes. Using multiple bandpass filters with relative photometry is termed absolute photometry. A plot of magnitude against time produces a light curve, yielding considerable information about the physical process causing the brightness changes. Precision photoelectric photometers can measure starlight around 0.001 magnitude.
The technique of surface photometry can also be used with extended objects like planets, comets, nebulae or galaxies that measures the apparent magnitude in terms of magnitudes per square arcsecond. Knowing the area of the object and the average intensity of light across the astronomical object determines the surface brightness in terms of magnitudes per square arcsecond, while integrating the total light of the extended object can then calculate brightness in terms of its total magnitude, energy output or luminosity per unit surface area.
Methods
Astronomy was among the earliest applications of photometry. Modern photometers use specialised standard passband filters across the ultraviolet, visible, and infrared wavelengths of the electromagnetic spectrum. Any adopted set of filters with known light transmission properties is called a photometric system, and allows the establishment of particular properties about stars and other types of astronomical objects. Several important systems are regularly used, such as the UBV system (or the extended UBVRI system), near infrared JHK or the Strömgren uvbyβ system.
Historically, photometry in the near-infrared through short-wavelength ultra-violet was done with a photoelectric photometer, an instrument that measured the light intensity of a single object by directing its light onto a photosensitive cell like a photomultiplier tube. These have largely been replaced with CCD cameras that can simultaneously image multiple objects, although photoelectric photometers are still used in special situations, such as where fine time resolution is required.
Magnitudes and colour indices
Modern photometric methods define magnitudes and colours of astronomical objects using electronic photometers viewed through standard coloured bandpass filters. This differs from other expressions of apparent visual magnitude observed by the human eye or obtained by photography: that usually appear in older astronomical texts and catalogues.
Magnitudes measured by photometers in some commonplace photometric systems (UBV, UBVRI or JHK) are expressed with a capital letter, such as "V" (mV) or "B" (mB). Other magnitudes estimated by the human eye are expressed using lower case letters, such as "v", "b" or "p", etc. E.g. Visual magnitudes as mv, while photographic magnitudes are mph / mp or photovisual magnitudes mp or mpv. Hence, a 6th magnitude star might be stated as 6.0V, 6.0B, 6.0v or 6.0p. Because starlight is measured over a different range of wavelengths across the electromagnetic spectrum and are affected by different instrumental photometric sensitivities to light, they are not necessarily equivalent in numerical value. For example, apparent magnitude in the UBV system for the solar-like star 51 Pegasi is 5.46V, 6.16B or 6.39U, corresponding to magnitudes observed through each of the visual 'V', blue 'B' or ultraviolet 'U' filters.
Magnitude differences between filters indicate colour differences and are related to temperature. Using B and V filters in the UBV system produces the B–V colour index. For 51 Pegasi, the B–V = 6.16 – 5.46 = +0.70, suggesting a yellow coloured star that agrees with its G2IV spectral type. Knowing the B–V results determines the star's surface temperature, finding an effective surface temperature of 5768±8 K.
Another important application of colour indices is graphically plotting star's apparent magnitude against the B–V colour index. This forms the important relationships found between sets of stars in colour–magnitude diagrams, which for stars is the observed version of the Hertzsprung-Russell diagram. Typically photometric measurements of multiple objects obtained through two filters will show, for example in an open cluster, the comparative stellar evolution between the component stars or to determine the cluster's relative age.
Due to the large number of different photometric systems adopted by astronomers, there are many expressions of magnitudes and their indices. Each of these newer photometric systems, excluding UBV, UBVRI or JHK systems, assigns an upper or lower case letter to the filter used. For example, magnitudes used by Gaia are 'G' (with the blue and red photometric filters, GBP and GRP) or the Strömgren photometric system having lower case letters of 'u', 'v', 'b', 'y', and two narrow and wide 'β' (Hydrogen-beta) filters. Some photometric systems also have certain advantages. For example, Strömgren photometry can be used to measure the effects of reddening and interstellar extinction. Strömgren allows calculation of parameters from the b and y filters (colour index of b − y) without the effects of reddening, as the indices m 1 and c 1.
Applications
There are many astronomical applications used with photometric systems. Photometric measurements can be combined with the inverse-square law to determine the luminosity of an object if its distance can be determined, or its distance if its luminosity is known. Other physical properties of an object, such as its temperature or chemical composition, may also be determined via broad or narrow-band spectrophotometry.
Photometry is also used to study the light variations of objects such as variable stars, minor planets, active galactic nuclei and supernovae, or to detect transiting extrasolar planets. Measurements of these variations can be used, for example, to determine the orbital period and the radii of the members of an eclipsing binary star system, the rotation period of a minor planet or a star, or the total energy output of supernovae.
CCD photometry
A CCD (charge-coupled device) camera is essentially a grid of photometers, simultaneously measuring and recording the photons coming from all the sources in the field of view. Because each CCD image records the photometry of multiple objects at once, various forms of photometric extraction can be performed on the recorded data; typically relative, absolute, and differential. All three will require the extraction of the raw image magnitude of the target object, and a known comparison object.
The observed signal from an object will typically cover many pixels according to the point spread function (PSF) of the system. This broadening is due to both the optics in the telescope and the astronomical seeing. When obtaining photometry from a point source, the flux is measured by summing all the light recorded from the object and subtracting the light due to the sky. The simplest technique, known as aperture photometry, consists of summing the pixel counts within an aperture centered on the object and subtracting the product of the nearby average sky count per pixel and the number of pixels within the aperture. This will result in the raw flux value of the target object. When doing photometry in a very crowded field, such as a globular cluster, where the profiles of stars overlap significantly, one must use de-blending techniques, such as PSF fitting to determine the individual flux values of the overlapping sources.
Calibrations
After determining the flux of an object in counts, the flux is normally converted into instrumental magnitude. Then, the measurement is calibrated in some way. Which calibrations are used will depend in part on what type of photometry is being done. Typically, observations are processed for relative or differential photometry.
Relative photometry is the measurement of the apparent brightness of multiple objects relative to each other. Absolute photometry is the measurement of the apparent brightness of an object on a standard photometric system; these measurements can be compared with other absolute photometric measurements obtained with different telescopes or instruments. Differential photometry is the measurement of the difference in brightness of two objects. In most cases, differential photometry can be done with the highest precision, while absolute photometry is the most difficult to do with high precision. Also, accurate photometry is usually more difficult when the apparent brightness of the object is fainter.
Absolute photometry
To perform absolute photometry one must correct for differences between the effective passband through which an object is observed and the passband used to define the standard photometric system. This is often in addition to all of the other corrections discussed above. Typically this correction is done by observing the object(s) of interest through multiple filters and also observing a number of photometric standard stars. If the standard stars cannot be observed simultaneously with the target(s), this correction must be done under photometric conditions, when the sky is cloudless and the extinction is a simple function of the airmass.
Relative photometry
To perform relative photometry, one compares the instrument magnitude of the object to a known comparison object, and then corrects the measurements for spatial variations in the sensitivity of the instrument and the atmospheric extinction. This is often in addition to correcting for their temporal variations, particularly when the objects being compared are too far apart on the sky to be observed simultaneously. When doing the calibration from an image that contains both the target and comparison objects in close proximity, and using a photometric filter that matches the catalog magnitude of the comparison object most of the measurement variations decrease to null.
Differential photometry
Differential photometry is the simplest of the calibrations and most useful for time series observations. When using CCD photometry, both the target and comparison objects are observed at the same time, with the same filters, using the same instrument, and viewed through the same optical path. Most of the observational variables drop out and the differential magnitude is simply the difference between the instrument magnitude of the target object and the comparison object (∆Mag = C Mag – T Mag). This is very useful when plotting the change in magnitude over time of a target object, and is usually compiled into a light curve.
Surface photometry
For spatially extended objects such as galaxies, it is often of interest to measure the spatial distribution of brightness within the galaxy rather than simply measuring the galaxy's total brightness. An object's surface brightness is its brightness per unit solid angle as seen in projection on the sky, and measurement of surface brightness is known as surface photometry. A common application would be measurement of a galaxy's surface brightness profile, meaning its surface brightness as a function of distance from the galaxy's center. For small solid angles, a useful unit of solid angle is the square arcsecond, and surface brightness is often expressed in magnitudes per square arcsecond. The diameter of galaxies are often defined by the size of the 25th magnitude isophote in the blue B-band.
Forced photometry
In forced photometry, measurements are conducted at a specified location rather than for a specified object. It is "forced" in the sense that a measurement can be taken even if there is no object visible (in the spectral band of interest) in the location being observed. Forced photometry allows extracting a magnitude, or an upper limit for the magnitude, at a chosen sky location.
Software
A number of free computer programs are available for synthetic aperture photometry and PSF-fitting photometry.
SExtractor and Aperture Photometry Tool are popular examples for aperture photometry. The former is geared towards reduction of large scale galaxy-survey data, and the latter has a graphical user interface (GUI) suitable for studying individual images.
DAOPHOT is recognized as the best software for PSF-fitting photometry.
Organizations
There are a number of organizations, from professional to amateur, that gather and share photometric data and make it available on-line. Some sites gather the data primarily as a resource for other researchers (ex. AAVSO) and some solicit contributions of data for their own research (ex. CBA):
American Association of Variable Star Observers (AAVSO).
Astronomyonline.org
Center for Backyard Astrophysics (CBA).
See also
Albedo
Aperture Photometry Tool - Software
Bidirectional reflectance distribution function
Hapke parameters
Radiometry
Redshift survey
Spectroscopy
References
External links
Astrophysics
Electromagnetic radiation
Light pollution
Observational astronomy
Photometric systems
Radiometry | Photometry (astronomy) | Physics,Astronomy,Engineering | 2,825 |
71,387,813 | https://en.wikipedia.org/wiki/HD%20106315 | HD 106315, or K2-109, is a single star with a pair of close-orbiting exoplanets, located in the constellation of Virgo. Based on parallax measurements, this system lies at a distance of 356 light years from the Sun. At that range, the star is too faint to be seen with the naked eye, as it has an apparent visual magnitude of 8.95. But it is slowly drifting closer with a radial velocity of −3 km/s. , multiplicity surveys have not detected any stellar companions to HD 106315.
The spectrum of HD 106315 presents as an ordinary F-type main-sequence star with a stellar classification of F5V, indicating it is generating energy through hydrogen fusion at its core. It is estimated to be roughly four billion years old but is spinning quickly with a rotation period of 5 days. The star is relatively metal-poor, having 60% of solar concentration of iron. It has only a low level of magnetic activity in its chromosphere, showing a minimal level of star spot coverage. The star has 11% more mass and a 29% larger radius than the Sun. It is radiating 2.4 times the luminosity of the Sun from its photosphere at an effective temperature of 6,300 K.
Planetary system
Two planets were detected by the transit method in 2017, using data from the extended Kepler mission (K2). Their large planetary radii imply both planets have a massive steam atmosphere for planet b and hydrogen-helium atmosphere for planet c. The planetary system of HD 106315 is rather unstable and current planetary orbits are the outcome of violent dynamical history, strongly affected by relativistic effects. The orbits of planets are nearly coplanar, and orbit of c is well aligned with the equatorial plane of the star, misalignment been equal to -10°.
Since 2017, a third outer planet with mass above 45 is suspected to exist in the system.
References
F-type main-sequence stars
Planetary systems with two confirmed planets
Planetary transit variables
Virgo (constellation)
BD+00 2910|
J12135339-0023365
106315 | HD 106315 | Astronomy | 449 |
4,191,649 | https://en.wikipedia.org/wiki/Pall%20Corporation | Pall Corporation, headquartered in Port Washington, New York and a wholly owned subsidiary of Danaher Corporation since 2015, is a global supplier of filtration, separations and purification products. Total revenues for fiscal year 2014 were $2.8 billion, with $103 million spent on R&D. Pall Corporation's business is split into two broad groups: Life Sciences (c.51%) and Industrial (c.49%). These business groups provide fluid management products and systems to customers in biotechnology, pharmaceutical, transfusion medicine, energy, electronics, municipal and industrial water purification, aerospace, transportation and broad industrial markets.
The company was founded by David B. Pall in 1946 as Micro Metallic Corporation.
History
Founded in 1946 as Micro Metallic Corporation.
In 1953, Pall purchased an industrial building at 30 Sea Cliff Ave, Glen Cove, NY (occupied until 1999). In 1958, Pall Corporation constructed a building at 36 Sea Cliff Ave (occupied it until 1971, when Pall Corporation sold the building to August Thomsen).
The company was renamed Pall Corp in 1957. In 1958 Pall began to develop filters for use in aircraft hydraulics, applied to the landing gears of American Airlines Boeing 707s. Then, Pall developed filters to purify jet fuel.
Through the 1960s, the business expanded, with sales of $6.7 million in 1960. Pall Europe Limited formed in 1966.
Pall Cortland was established in 1961, purchased from Trinity Equipment Company.
In the 1970s, Pall became a leader in fine filtration. Sales reached $88 million in 1978. Major contribution in medical applications.
Pall played a major role in the cleanup of the 1979 Three Mile Island nuclear accident.
The company continued to grow in the 80's and 90's, adding applications and products. In the mid-80's, Pall contributed to the construction of the Eurotunnel under the English Channel, providing solutions to hydraulic operations needed to bore through the channel bedrock. In 1988, they began selling a filter for blood transfusions that reduced leukocyte levels below all other existing filters. Centrisep air cleaners were integrated into U.S. Army and Royal Air Force (UK) helicopters to reduce sand and dust out of engines during Operation Desert Storm in 1991.
In 1997 the company acquired Gelman sciences, and in 1998, Pall acquired German company Rochem.
In response to an article in Forbes magazine about dioxane in Michigan, Farsad Fotouhi, VP of Life Sciences division, responded "Pall is in full compliance with the Consent Judgment it entered with the Michigan Department of Environmental Quality (MDEQ), which serves as the legal framework for the cleanup." Later in 2013, Scio Township Supervisor Clark said he's heard from Fotouhi that there will be a staff of about 20 people that will remain on the site.
On May 31, 2015, Danaher Corporation announced it would acquire Pall Corporation. The transaction closed in August 2015, with Danaher paying $127.20 per share or about $13.8 billion. The acquisition was completed on August 31, 2015.
In September 2022, it was announced that Pall Life Sciences will be merging with Cytiva to create a new Biotechnology Group within Danaher.
Details
Today, the company is divided into two separate, integrated businesses: Pall Life Sciences and Pall Industries.
The Scientific & Lab Services employed 175 people worldwide at 29 locations, in 2011. The R&D group has 12 sites, with seven in the United States. The main industrial technical center is at Cortland, NY.
Pall has plants in New Port Richey, DeLand, Florida, Cortland, New York, Timonium, Maryland, Fajardo, Puerto Rico, Ilfracombe, Portsmouth and locations around the world. In 2013 it announced plans to close its plants in Ann Arbor and Fort Myers, Florida.
Achievements
1990: Dr. Pall is awarded the National Medal of Technology for patenting and commercializing over 100 filtration and other fluid clarification products beneficial to society and for building Pall Corporation into a global company.
2008: Dr. Pall is posthumously inducted into the National Inventors Hall of Fame for his invention of the leukoreduction filter.
2009: Pall Corporation is named one of the greenest companies in America in Newsweek’s September 28 issue. The company was ranked second in the industrial goods sector and 47th among America's largest companies.
2011: Pall Corporation is awarded the Engineering Materials Achievement Award (EMAA) by ASM International. The company was recognized for its porous iron aluminide technology.
2011: Pall Corporation is named a top green company in Newsweek's third annual Green Rankings. The company was ranked fifth in the capital goods sector and 69th among the U.S. 500 list.
References
External links
Pall Corporation official site
50 years of Pall
Companies formerly listed on the New York Stock Exchange
Industrial machine manufacturers
Manufacturing companies established in 1946
American brands
2015 mergers and acquisitions
Pall Corp.
Manufacturing companies based in New York (state)
1946 establishments in New York (state)
Danaher subsidiaries | Pall Corporation | Engineering | 1,070 |
15,962,283 | https://en.wikipedia.org/wiki/Grave%20orb | A grave orb is a petrosphere that was put on a person's tomb. Grave orbs were made throughout Scandinavia from the Pre-Roman Iron Age until the Vendel era.
The grave orb could have been selected for its round shape or shaped by hand. They were then put in the centre of a burial site. Tumuli, stone circles and stone ships often have a reclined or raised central stone, and grave orbs derive from this practice. They were of ritual or symbolic significance.
Some grave orbs are engraved with ornaments, such as the orb at Inglinge hög or Barrow of Inglinge near Ingelstad in Småland, Sweden. Hög is from the Old Norse word haugr meaning mound or barrow.
See also
Stone balls
Stone spheres of Costa Rica
Carved stone balls of Scotland
Sources
The article 'Gravklot' in Nationalencyklopedin (1992).
Rock art in Europe
Archaeological artefact types
Prehistoric art
Prehistoric Scandinavia
Germanic archaeological artifacts
Migration Period
Stones | Grave orb | Physics | 209 |
46,343,105 | https://en.wikipedia.org/wiki/Hiroshima%20Synchrotron%20Radiation%20Center | The Hiroshima Synchrotron Radiation Center, also known as Hiroshima Synchrotron Orbital Radiation (HiSOR), at Hiroshima University is a national user research facility in Japan. It was founded in 1996 by the University Science Council at Hiroshima University initially as a combined educational and research facility before opening to users in Japan and across the world in 2002. It is the only synchrotron radiation experimental facility located at a national university in Japan.
The HiSOR experimental hall contains two undulators that produce light in the ultraviolet to soft x-ray range. A total of 16 beamlines are supported by bending magnet and undulator radiation for use in basic studies of life sciences and physical sciences, especially solid-state physics.
History
Development began with an exploratory committee formed in 1982, which gathered input from Hiroshima University, local agencies, and prefectural agencies.
Between 1986 and 1988, several proposals and budget requests were submitted to the Ministry of Education of Japan for a medium-scale synchrotron radiation facility. In 1989, a chair for synchrotron radiation was established at Hiroshima University Graduate School of Science and studies began for the planning of a medium-scale synchrotron radiation source. However, with the approval of SPring-8 just 210 km away, the design emphasis of the project shifted away from the originally planned 1.5 GeV to a compact light source design which would be more complementary to a high-energy accelerator like SPring-8 and more appropriate for a university. The compact synchrotron concept was then renamed as the HSRC, while the storage ring itself would be named HiSOR.
In 1996, the HSRC building was inaugurated and a 10-year research organization plan was developed for HiSOR by the Education and Research Council of Hiroshima University. The intent was to create a facility as part of the Graduate School of Science to serve as both a research and educational tool, specifically supporting master's students in the Department of Physical Sciences. In 1997, the first light from HiSOR was emitted and in 1999, the Okayama University beamline was constructed.
In April 2002, the HSRC was repurposed as a national user facility and the divisions were expanded to basic science, accelerator research, and synchrotron radiation research. As part of the reopening, the HSRC joined the Council for Research Institutes and Centers of Japanese National Universities.
An annual Hiroshima International Symposium on Synchrotron Radiation is held to showcase synchrotron radiation and nanoscience research work from Japan and abroad and for students to promote their dissertation research and HSRC's activities. In terms of outreach, the HSRC also has programs for facility tours, synchrotron radiation training, involvement with high schools, and open lectures to the public.
Design
A microtron developed by Sumitomo Heavy Industries is used as the injection system, an extension of a design concept from the University of Wisconsin. Its compact design uses 2.7 T bending magnets instead of conventional 1.2 T bending magnets, allowing the light to achieve the same power and wavelength as a medium-scale synchrotron without using a higher energy beam.
The HiSOR has two insertion devices, a linear undulator and a helical undulator, in the two linear sections of the ring and has an electron energy of 0.7 GeV with a nominal beam current of 300 mA. The ring itself has a circumference of 22 m. The photon yield is 1.2×1011 photons s−1 mrad−2 at 5 keV, in 0.1% bandwidth, for 300 mA.
See also
List of synchrotron radiation facilities
References
External links
Hiroshima University
Synchrotron radiation facilities | Hiroshima Synchrotron Radiation Center | Materials_science | 757 |
54,819,249 | https://en.wikipedia.org/wiki/Naphthol%20AS | Naphthol AS is an organic compound with the formula C10H6(OH)C(O)NHC6H5. It is the anilide of 3-hydroxy-2-carboxynaphthalene. Many analogous compounds are known, designated with a differing suffix. For example, in Naphthol AS-OL, the aryl substituent on nitrogen is C6H4-2-OCH3. These compounds are used as coupling partners in the preparation of some azo dyes.
History
In 1911, it was found to be a good precursor to dyes for wool by chemists at K. Oehler Anilin- und Anilinfarbenfabrik Offenbach.
References
Organic pigments
Azo dyes
Amides | Naphthol AS | Chemistry | 163 |
11,384,520 | https://en.wikipedia.org/wiki/Rossall%20hockey | Rossall hockey or RossHockey is a unique form of hockey played only at Rossall School, in Fleetwood, on the Fylde coast, Lancashire, England. The game is unique to Rossall School and is played on the beach next to the school during the Lent term only, with the pitch being marked by dragging the hockey sticks in the sand before each match. It is a brutal beach game born of rugby but played with hockey-like sticks by girls as well as boys at the school. It dates back to the 19th century when pitches were too wet for rugby. It is one of the few school coded sports to have remained in use despite the dominance of other national codes in modern sport. The only other examples of school coded sport in the United Kingdom that remain are those of the various Fives codes; of which Rossall has its own, as well as Harrow football, Winchester College football, the Eton wall game and the Eton field game.
History
Rossall hockey was referenced in the first issue of the Rossallian in 1867, though its exact date of creation is not known. Rossall Hockey started as a derivation of Rossall Football, an adaptation of the Eton field game introduced to the school in 1857 by a school master who had been a student at Eton College.
Initially the rules of RossHockey were slightly different from those of today, with scoring occurring by a system of goals and rougeables. It is also known that there were no restrictions on the number of players in a game and there was no fixed time of play - indeed one game lasted for two days.
The official rules were drawn up in 1873 and two years later the first House RossHockey competition took place. The rules were amended again in 1900 to abolish rougeables. Emphasis has always been placed on the game being one of skill and dribbling - as well as one of brute force.
In 1997 the game was nearly abandoned after over 130 years of history when the supplier of the sticks went bankrupt. A replacement supplier was found in Eccles where they had made lacrosse sticks for many years. The new sticks are slightly less ornate than the traditional ones and also made of hickory rather than ash but the gameplay has not been affected.
Rules
Gameplay
The pitch should be drawn up as indicated in the diagram, with the numbers indicating measurements in paces. The pitch should also be 80 paces in length.
The game begins with a bully at the centre circle. A bully consists of seven players from each team lined up in opposing lines. Three players from each team stand out of the bully as flies. Four sticks from each team must be placed into the centre to trap the ball.
When the whistle is blown the match begins with each team driving forward in their lines to wrench the ball from the control of the other team.
When the ball is freed from a bully the teams must each chase after it and force it in across the goal line between the opposing team's posts.
If a player loses the ball by running ahead of it, another player from their team must take it on. The ball must always be approached from the rear by a player who wishes to take it on - if they fail to do so then they are considered offside.
Scoring occurs only when the ball is pushed over the line by a player within the "D".
Fouls
Any of the following are fouls and will result in a free hit except if they are committed in the "D" by the defending team, in which case a line-bully is observed:
References
Rossall School
School sport in the United Kingdom
Variations of hockey
Youth sport in England | Rossall hockey | Astronomy | 730 |
29,440,830 | https://en.wikipedia.org/wiki/CESG%20Listed%20Adviser%20Scheme | The CESG Listed Adviser Scheme was a programme run by CESG, to provide a pool of information assurance consultants to government departments and other public-sector bodies in the UK.
CLAS consultants advised on systems that handle protectively marked information, up to and including SECRET; for instance, they may have advised on GSI accreditation. CLAS consultants held a security clearance, at least SC.
CLAS consultants developed risk assessments in line with IS1, and risk management and accreditation document sets (RMADS) in line with IS2.
In 2011, entry to CLAS was closed while a replacement system was being designed.
By 2013 'new' CLAS was implemented and open for membership. 'New' CLAS required that members were CESG Certified Professionals.
CLAS was closed in January 2016.
CESG Certified Professionals (CCP)
The CESG Certified Professional (CCP) scheme recognises the expertise of those working in the information assurance and cyber security arenas in both government and industry. It sets the standard for IA professionals working in this sector and provides a rigorous and independent assessment of the competence of IA professionals. CCP status is an endorsement of IA expertise and confirms that information risk in support of your business is managed in a balanced and pragmatic way.
Now that CLAS has closed, CCP is the only CESG-approved credential that applies to individual professionals rather than companies.
External links
CLAS homepage
CLAS knowledgebase
Article: What is a CLAS Consultant?
Maintained list of ex-CLAS members (TSAR)
References
Computer security in the United Kingdom
GCHQ
Information assurance standards
Information technology organisations based in the United Kingdom
IT risk management | CESG Listed Adviser Scheme | Technology | 338 |
29,333,787 | https://en.wikipedia.org/wiki/Gross%20ton%20mile | Gross ton mile (GTM), or its related units gross tonne–kilometre and thousand gross tonne mile (kgtm) are units of measurement commonly used in rail transportation. Gross ton kilometre is the product of total weight (including the weight of lading cars and locomotives) and the distance moved by a train.
References
Rail freight transport
Units of measurement | Gross ton mile | Mathematics | 74 |
5,706,047 | https://en.wikipedia.org/wiki/World%20Urban%20Forum%203 | World Urban Forum III was an international UN-Habitat event on urban sustainability, also known as WUF3 (World Urban Forum) and FUM3 (Forum Urbain Mondial). WUF3 was organized by the UN-Habitat and facilitated and funded by the Government of Canada. It was held on 19–23 June 2006 in Vancouver to help solve urgent problems of the world's cities.
Conference objective
The theme of the third session of the world urban forum was: "Sustainable Cities – Turning Ideas into Action".
"From Ideas to Action" was the intended outcome of the conference. Officially it was suggested that this conference would be considered a success if every participant took home and implemented at least one new idea.
Global urban context
Within the next 50 years, two-thirds of the world's population will live in urban areas. As these cities expand, the world community faces the challenge of minimizing the growing poverty crisis and improving the urban poor's access to basic facilities, such as shelter, clean water and sanitation. World Urban Forum 3 brought together thousands of the world's best thinkers on urbanization – experts, decision makers and members of public and private institutions – to zero in on solutions to these key 21st century challenges.
Defining the conference
Habitat Jam, a three-day international online event, was conceived to set the stage for the WUF3 conference. Seventy actionable ideas were collected through the Jam and were used to define themes and shape discussion topics for delegates attending the forum. Participation in Habitat Jam was open to public and private-sector organizations and individuals around the world with an interest in urban issues. While the Jam is over the discussions remain available online.
Participation
Attendance at WUF3 was estimated at 11,418 people registered from more than 100 countries. The number of participants was 9,689 while 1,847 were support staff and volunteers.
The gender ratios were 46.7% female and 52.1% male. Participants identified as Government, Parliamentarians, or Local Authority comprised 3,094 of the participants. The remaining participants were classified as Non-governmental organizations, Private Sector, Professional and Research Institutions, Foundations, Media, Inter-Governmental Organizations, Other Participants, Canada Secretariat and No Affiliation Indicated.
Compared to previous forums there was a notable increase in private sector participation. Up from 203 to 1,187 private sector participants between WUF2 and WUF3 in Vancouver.
References
External links
World Urban Forum 3
WUF3 Session Videos in English and French
2006 conferences
2000s in Vancouver
International conferences in Canada
United Nations conferences
Urban planning
Human settlement
Urbanization
2006 in Canada
Canada and the United Nations | World Urban Forum 3 | Engineering | 533 |
45,584,344 | https://en.wikipedia.org/wiki/Dagmar%20H%C3%BClsenberg | Dagmar Hülsenberg ( Hinz; born 2 December 1940, in Sonneberg) is a German materials scientist and university professor.
In 1975, at age 34, she became the youngest full professor in the German Democratic Republic. By that time she had already distinguished herself by obtaining doctorates in two barely related disciplines: Economics/Cost accounting (1969) and Engineering/Materials science (1970).
Life
Dagmar Hinz was born soon after the start of the Second World War in Sonneberg, a small town in the centre of southern Germany, located between Würzburg and Leipzig. Before she was 3 her father had been killed in the fighting. Her mother worked as a milliner. By the time she had successfully completed her schooling the war had ended, in May 1945, and after the armies had finished repositioning themselves Sonneberg had ended up at the edge of the Soviet occupation zone in what remained of Germany. The entire zone was refounded as the German Democratic Republic in October 1949. During the later 1950s Hinz undertook an apprenticeship for work as a Ceramics and Pottery technician. She later recalled that she had really wanted to become an economist, but had been unable to obtain a study-place. In 1960, with support from her boss at the ceramics factory, she was able to obtain a place at the Freiberg University of Mining and Technology where she studied Silicate Metallurgy, emerging with a degree in 1965. She then obtained a university position as a research assistant and started working on a doctorate.
During the 1960s she married the economist Frieder Hülsenberg. At this time Hülsenberg was writing a book, drafts for which his wife read. She alerted him to an important inconsistency in the text which he was obliged to discuss with his co-author, the Dresden Economics Professor Otto Gallenmüller. One upshot of the ensuing discussions was that Dagmar Hülsenberg hurriedly mastered relevant portions of the Economics syllabus and, in 1969, obtained a doctorate from Freiberg University in Economics for a dissertation entitled "Determining an optimal number of cost centres and cost objects, with particular attention to error aggregation" Just a year later, in 1970, she received a second doctorate, this time in Material Sciences: her dissertation on this occasion was entitled "High-temperature deformation of heterogeneous materials, illustrated using fire-resistant chamotte (fire clay)"
In 1970, she moved to the (Ministry of light industry) and later to the (Ministry for the glass and ceramics industries) where she was involved in preparing the national plan for science and technology (). Looking back, she recalled that she had not much enjoyed work at the ministries: five years had been enough.
In 1975 she switched again, back to the academic world, accepting the newly created professorship of "Glass and Ceramics Materials and Technology" at the Ilmenau Technical Academy, back in Thuringia. At the time she was the youngest professor in the country, and her tenure would comfortably outlast the German Democratic Republic itself, ending only in 2007.
From 1984 until 1990 Dagmar Hülsenberg served as a member of the National Research Council.
Between 1976 and 1987 she chaired the Silicates Technology Expert Committee of the FDGB Chamber of Technology, and from 1987 until 1992 she served as (the last) president of the Chamber of Technology, in succession to Manfred Schubert who had died young. She became a corresponding member of the national German Academy of Sciences in 1989. and has been a member of the Saxony Academy of Sciences, based in Leipzig since 1986: she became a member of the presidium in 2004. She is a member of the German Ceramics Society, the German Glass Technology Society and of the German Academy of Science and Engineering.
References
External links
1940 births
Living people
People from Sonneberg
Socialist Unity Party of Germany members
German materials scientists
Women materials scientists and engineers
East German women
Members of the German Academy of Sciences at Berlin | Dagmar Hülsenberg | Materials_science,Technology | 808 |
52,489,138 | https://en.wikipedia.org/wiki/Amanita%20lividopallescens | Amanita lividopallescens, also known as the pale amanita, is a species of Amanita in Europe that grows near oaks.
References
External links
lividopallescens
Fungus species | Amanita lividopallescens | Biology | 44 |
1,200,773 | https://en.wikipedia.org/wiki/Midparent | In human genetics the midparent value of a trait is defined as the average of the trait value of the father and a scaled version of that of the mother. This value can be used in a study to analyze the data set without heeding sex effects. Studying quantitative traits in heritability studies may be complicated by sex differences observed for the trait.
Well-known examples include studies of humans' height, whose midparent value hmp is given by:
where hf is the father's height, and hm the mother's.
The coefficient 1.08 serves as a scaling factor. After the 1.08 scaling, the mean of the mother's height is the same as that of the father's, and the variance is closer to the father's; in this way, sex difference can be ignored.
References
Genetics | Midparent | Biology | 172 |
25,341,445 | https://en.wikipedia.org/wiki/Doodlebug%20tractor | Doodlebug tractor is the colloquial American English name for a tractor home-made in the United States during World War II, when production tractors were in short supply. The doodlebug of the 1940s was usually based on a 1920s or 1930s era Ford automobile which was then modified either by the complete removal or alteration of some of the vehicle body. The preservation of examples of the doodlebug tractor has become popular in New England and upstate New York where there are several clubs holding monthly meet-ups in the summer months to put their contraptions to the test by pulling large stone boats in a tractor pull.
History
Doodlebugs had many names — Friday Tractors, Scrambolas, Jitterbugs, Field Crawlers, Ruxells and many others, as well as the most common, The DoodleBug, which was a nickname for the aftermarket tractor kit made by David Bradley, "The old DB". Initially, the idea of the homemade tractor came from several catalog and implement companies in the mid-1920s to the mid-1930s, such as New Deal, Minnesota-based tractor company offering low priced tractors during the New Deal era, Peru Plow Co., Thrifty Farmer (offering Ford or Chevrolet auto to tractor conversions), Sears Roebuck & Co., Montgomery Ward, Pull Ford, and Johnson Mfg. Co.
The conversion kits were expensive, some as much as $300, and farmers, hit hard by the Great Depression were a resourceful lot. Magazines like Popular Mechanics and Mechanix Illustrated provided instructions for building a "Handy Henry" from that "old Ford sitting in your back yard, using simple tools anyone would have". The cost to build a "Handy Henry" made from an old Model T car or truck was about $20, according to the 1936 edition of the Handy Man's Home Manual, and this provided a serviceable vehicle with rubber tires, a big truck rear end and two transmissions to make up for the gear reduction with which the kits came.
These doodlebugs were used to plow, make hay, haul logs, and pull out stumps. To do all this, the doodlebug needed good ground clearance for use in any conditions and climbing almost any terrain. For protection they had a hood, cowl radiator, a small seat, some had a small truck bed, and most had a hitching point with which to tow.
Sweden
In Sweden, tractors made from automobiles became popular among small farmers in the 1930s and remained so until small tractors became available in the 1950s. A government ordinance in 1940 (Kungörelse 1940: 440 om hänförande av vissa automobiler till fordonstypen motorredskap) was the first to set down rules for what modifications were necessary to change the class of vehicle from automobile to motorized farm implement, including a speed limit to 30 kilometers per hour (20 mph). Even though doodlebugs are no longer used for farming in Sweden, the age limit of 16 years (recently changed to 15 years) make them a popular hobby for teenagers in rural areas.
See also
Automobile-conversion tractors and other homemade versions
References
External links
Pictures of home-made tractors from USA
Pictures of home-made tractors from Sweden
Pictures of home-made tractors from the rest of the world
Tractors
Tractor pulling | Doodlebug tractor | Engineering | 687 |
31,254,802 | https://en.wikipedia.org/wiki/Transposon%20tagging | In genetic engineering, transposon tagging is a process where transposons (transposable elements) are amplified inside a biological cell by a tagging technique. Transposon tagging has been used with several species to isolate genes. Even without knowing the nature of the specific genes, the process can still be used.
In plants
By molecular separation of transposons, from a cell nucleus, the cloning is enabled for genes which contain the transposons.
By using transposon tagging, researchers have been able to add genetic elements from maize (corn) and Antirrhinum into some other species (such as tobacco, aspen and others). A gene responsible for a particular phenotype can be cloned within a given species, when movement is accompanied by the presence of a mutant phenotype.
References
Further reading
Transposon Tagging, North Dakota State University
A.M. Settles, Transposon Tagging and Reverse Genetics, University of Florida
Biochemistry detection methods
Cloning
Genetic engineering
Genetics techniques | Transposon tagging | Chemistry,Engineering,Biology | 209 |
31,332,185 | https://en.wikipedia.org/wiki/Fulde%E2%80%93Ferrell%E2%80%93Larkin%E2%80%93Ovchinnikov%20phase | The Fulde–Ferrell–Larkin–Ovchinnikov (FFLO) phase (also occasionally called the Larkin–Ovchinnikov–Fulde–Ferrell phase, or LOFF) can arise in a superconductor under large magnetic fields. Among its characteristics are Cooper pairs with nonzero total momentum and a spatially non-uniform order parameter, leading to normally conducting areas in the system.
History
Two independent publications in 1964, one by Peter Fulde and Richard A. Ferrell
and the other by Anatoly Larkin and Yuri Ovchinnikov,
theoretically predicted a new state appearing in a certain regime of superconductors at low temperatures and in high magnetic fields. This particular superconducting state is nowadays known as the Fulde–Ferrell–Larkin–Ovchinnikov state, abbreviated FFLO state (also LOFF state).
Since then, experimental observations of the FFLO state have been searched for in different classes of superconducting materials, first in thin films and later in more exotic superconductors such as heavy-fermion
and organic superconductors. Good evidence for the existence of the FFLO state was found in organic superconductors using nuclear magnetic resonance (NMR) and studies of heat capacity.
In recent years, the concept of the FFLO state has been used in the field of atomic physics and experiments to detect the state in atomic ensembles in optical lattices. Moreover, there are indicators of the FFLO phase existence in two-component Fermi gases confined in a harmonic potential. These signatures are suppressed neither by phase separation nor by vortex lattice formation.
Theory
If a BCS superconductor with a ground state consisting of Cooper pair singlets (and center-of-mass momentum q = 0) is subjected to an applied magnetic field, then the spin structure is not affected until the Zeeman energy is strong enough to flip one spin of the singlet and break the Cooper pair, thus destroying superconductivity (paramagnetic or Pauli pair breaking). If instead one considers the normal, metallic state at the same finite magnetic field, then the Zeeman energy leads to different Fermi surfaces for spin-up and spin-down electrons, which can lead to superconducting pairing where Cooper pair singlets are formed with a finite center-of-mass momentum q, corresponding to the displacement of the two Fermi surfaces.
A non-vanishing pairing momentum leads to a spatially modulated order parameter with wave vector q.
Experiment
For the FFLO phase to appear, it is required that Pauli paramagnetic pair-breaking is the relevant mechanism to suppress superconductivity (Pauli limiting field, also Chandrasekhar-Clogston limit). In particular, orbital pair breaking (when the vortices induced by the magnetic field overlap in space) has to be weaker, which is not the case for most conventional superconductors. Certain unusual superconductors, on the other hand, may favor Pauli pair breaking: materials with large effective electron mass or layered materials (with quasi-two-dimensional electrical conduction).
Heavy-fermion superconductors
Heavy-fermion superconductivity is caused by electrons with a drastically enhanced effective mass (the heavy fermions, also heavy quasiparticles), which suppresses orbital pair breaking. Furthermore, certain heavy-fermion superconductors, such as CeCoIn5, have a layered crystal structure, with somewhat two-dimensional electronic transport properties. Indeed, in CeCoIn5 there is thermodynamic evidence for the existence of an unconventional low temperature phase within the superconducting state. Subsequently, neutron diffraction experiments showed that this phase also exhibits incommensurate antiferromagnetic order and that the superconducting and magnetic ordering phenomena are coupled to one another.
Organic superconductors
Most organic superconductors are strongly anisotropic, in particular there are charge-transfer salts based on the molecule BEDT-TTF (or ET, "bisethylendithiotetrathiofulvalene") or BEDT-TSF (or BETS, "bisethylendithiotetraselenafulvalene") that are highly two-dimensional. In one plane, the electric conductivity is high compared to a direction perpendicular to the plane. When applying large magnetic fields exactly parallel to the conducting planes, penetration depth demonstrates and specific heat confirms the existence of the FFLO state. This finding was corroborated by NMR data that proved the existence of an inhomogeneous superconducting state, most probably the FFLO state.
References
Superconductivity | Fulde–Ferrell–Larkin–Ovchinnikov phase | Physics,Materials_science,Engineering | 978 |
54,880,180 | https://en.wikipedia.org/wiki/Golden%20Canopy%20of%20the%20Temple%20of%20the%20Tooth | The Golden Canopy of the Temple of the Tooth () is a canopy used to cover the Relic of the tooth of the Buddha, housed in the Sri Dalada Maligawa (Temple of the Tooth) in Kandy Sri Lanka.
In 1986 the Prime Minister Ranasinghe Premadasa made an official visit to the temple to pay homage to the sacred tooth relic. During this visit, the chief monks complained about water leaking from the roof and Premadasa pledged to cover the roof with a bronze sheet. Six months later, Premadasa formally announced plans to build a golden canopy over the inner shrine room of the temple. There were a number of objectors to the proposal including the Director of the Sri Lankan Department of Archeology, Roland Silva, arguing that a canopy over the existing roof would risk the structural integrity of the building and the temple's heritage value, given that there had been no additions made to the building since the last King of Kandy, Sri Vikrama Rajasinha, had occupied the throne. On 31 December 1987 the golden canopy, which cost more than Rs 20M, was officially unveiled by Premadasa. The gold plated tiles on the canopy were imported from Japan and installed upon a steel frame. As the use of concrete was not practical due to the limited timeframe for construction a steel frame was erected however this resulted in the canopy being subject to swaying so further steel supports were installed, projecting from the upper level of the Dalada Museum, directly behind the Palle Mahala (Tevava Chamber).
Political commentators at the time attribute Premadasa's decision to erected the golden canopy as being a significant factor in his subsequent election to the country's presidency in January 1988. The canopy over the country's most sacred relic symbolising and reinforcing the public view of his commitment that the country should remain a Sinhalese Buddhist nation.
In 2002 the canopy sheets were refurbished using 4,000 gold plated ceramic tiles produced in Sri Lanka.
In 2017 Prime Minister Ranil Wickramasinghe publicly promised that the canopy will be renovated. A week after, President Maithripala Sirisena gave Rs. 45 million for gold plating the golden canopy.
References
Roofs
Ceilings
1987 establishments in Sri Lanka
Buddhist temples in Kandy | Golden Canopy of the Temple of the Tooth | Technology,Engineering | 463 |
1,010,167 | https://en.wikipedia.org/wiki/Ceruloplasmin | Ceruloplasmin (or caeruloplasmin) is a ferroxidase enzyme that in humans is encoded by the CP gene.
Ceruloplasmin is the major copper-carrying protein in the blood, and in addition plays a role in iron metabolism. It was first described in 1948. Another protein, hephaestin, is noted for its homology to ceruloplasmin, and also participates in iron and probably copper metabolism.
Function
Ceruloplasmin (CP) is an enzyme () synthesized in the liver containing 6 atoms of copper in its structure. Ceruloplasmin carries more than 95% of the total copper in healthy human plasma. The rest is accounted for by macroglobulins. Ceruloplasmin exhibits a copper-dependent oxidase activity, which is associated with possible oxidation of Fe2+ (ferrous iron) into Fe3+ (ferric iron), therefore assisting in its transport in the plasma in association with transferrin, which can carry iron only in the ferric state. The molecular weight of human ceruloplasmin is reported to be 151kDa.
Despite extensive research, much is still unknown about the exact functions of CP, most of the functions are attributed to CP focus on the presence of the Cu centers. These include copper transport to deliver the Cu to extrahepatic tissues, amine oxidase activity that controls the level of biogenic amines in intestinal fluids and plasma, removal of oxygen and other free radicals from plasma, and the export of iron from cells for transport through transferrin.
Mutations have been known to disrupt the binding of copper to CP and will disrupt iron metabolism and cause an iron overload.
Ceruloplasmin is a relatively large enzyme (~10 nm); the larger size prevents the bound copper from being lost in a person's urine during transport.
Active site structure
The multicopper active site of CP contains a type I (T1) mononuclear copper site and a trinuclear copper center ~ 12-13 Å away (see figure 2). The tricopper center consists of two type III (T3) coppers and one type II (T2) copper ion. The two T3 copper ions are bridged by a hydroxide ligand while another hydroxide ligand links the T2 copper ion to the protein. The T1 center is bridged to the tricopper center by two histidine (His1020, His1022) residues and one Cys(1021) residue. The substrate binds near the T1 center and is oxidized by the T1 Cu2+ ion forming the reduced Cu+ oxidation state. The reduced T1 Cu+ then transfers the electron through the one Cys and two His bridging residues to the tricopper center. After four electrons have been transferred from the substrates to the copper centers, an O2 binds at the tricopper center and undergoes a four-electron reduction to form two molecules of water.
Regulation
A cis-regulatory element called the GAIT element is involved in the selective translational silencing of the Ceruloplasmin transcript.
The silencing requires binding of a cytosolic inhibitor complex called IFN-gamma-activated inhibitor of translation (GAIT) to the GAIT element.
Clinical significance
Like any other plasma protein, levels drop in patients with hepatic disease due to reduced synthesizing capabilities.
Mechanisms of low ceruloplasmin levels:
Gene expression genetically low (aceruloplasminemia)
Copper levels are low in general
Malnutrition/trace metal deficiency in the food source
Zinc toxicity, due to induced copper deficiency
Copper does not cross the intestinal barrier due to ATP7A deficiency (Menkes disease and Occipital horn syndrome)
Delivery of copper into the lumen of the ER-Golgi network is absent in hepatocytes due to absent ATP7B (Wilson's disease)
Copper availability doesn't affect the translation of the nascent protein. However, the apoenzyme without copper is unstable. Apoceruloplasmin is largely degraded intracellularly in the hepatocyte and the small amount that is released has a short circulation half life of 5 hours as compared to the 5.5 days for the holo-ceruloplasmin.
Ceruloplasmin can be measured by means of a blood test; this can be done using immunoassays . The sample is spun and separated; it is stored around 4 °C Celsius for three days. This test is to determine if there are signs of Wilson disease. Another test that can be done is a urine copper level test; this has been found to be less accurate than the blood test. A liver tissue test can be done as well.
Mutations in the ceruloplasmin gene (CP), which are very rare, can lead to the genetic disease aceruloplasminemia, characterized by hyperferritinemia with iron overload. In the brain, this iron overload may lead to characteristic neurologic signs and symptoms, such as cerebellar ataxia, progressive dementia, and extrapyramidal signs. Excess iron may also deposit in the liver, pancreas, and retina, leading to cirrhosis, endocrine abnormalities, and loss of vision, respectively.
Deficiency
Lower-than-normal ceruloplasmin levels may indicate the following:
Wilson disease (a rare [UK incidence 2/100,000] copper storage disease).
Menkes disease (Menkes kinky hair syndrome) (rare – UK incidence 1/100,000)
Copper deficiency
Aceruloplasminemia
Zinc toxicity
Excess
Greater-than-normal ceruloplasmin levels may indicate or be noticed in:
copper toxicity / zinc deficiency
pregnancy
oral contraceptive pill use
lymphoma
acute and chronic inflammation (it is an acute-phase reactant)
rheumatoid arthritis
Angina
Alzheimer's disease
Schizophrenia
Obsessive-compulsive disorder
Reference ranges
Normal blood concentration of ceruloplasmin in humans is 20–50 mg/dL.
References
Further reading
External links
GeneReviews/NCBI/NIH/UW entry on Aceruloplasminemia
OMIM entries on Aceruloplasminemia
Acute-phase proteins
Chemical pathology
EC 1.16.3
Hepatology
Iron metabolism
Copper enzymes | Ceruloplasmin | Chemistry,Biology | 1,351 |
2,903,774 | https://en.wikipedia.org/wiki/40%20Bo%C3%B6tis | 40 Boötis is a single star located 166.5 light years away from the Sun in the northern constellation of Boötes. It is visible to the naked eye as a dim, yellow-white hued star with an apparent visual magnitude of 5.64. The star is moving away from the Earth with a heliocentric radial velocity of +12 km/s.
The Hipparcos catalogue (1997) lists a stellar classification of F1 III–IV, matching the luminosity class of an aging star that is evolving into a giant. Earlier, Cowley and Bidelman (1979) listed a class of F2 III, while Sato and Kuji (1990) found a main sequence class of F0V. It is around 1.2 billion years old with a relatively high rotation rate, showing a projected rotational velocity of 72.5 km/s. The star has 1.5 times the mass of the Sun and 2.4 times the Sun's radius. It is radiating 11.6 times the luminosity of the Sun from its photosphere at an effective temperature of 7,070 K.
References
F-type giants
Boötes
Durchmusterung objects
Bootis, 40
132772
073369
5588 | 40 Boötis | Astronomy | 257 |
242,763 | https://en.wikipedia.org/wiki/Anacrusis | In poetic and musical meter, and by analogy in publishing, an anacrusis (from , , literally: 'pushing up', plural anacruses) is a brief introduction. In music, it is also known as a pickup beat, or fractional pick-up, i.e. a note or sequence of notes, a motif, which precedes the first downbeat in a bar in a musical phrase.
It is a set of syllables or notes, or a single syllable or note, which precedes what is considered the first foot of a poetic line (or the first syllable of the first foot) in poetry and the first beat (or the first beat of the first measure) in music that is not its own phrase, section, or line and is not considered part of the line, phrase, or section which came before, if any.
Poetry
In poetry, a set of extrametrical syllables at the beginning of a verse is said to stand in anacrusis ( "pushing up"). "An extrametrical prelude to the verse," or, "extrametrical unstressed syllables preceding the initial lift." The technique is seen in Old English poetry, and in lines of iambic pentameter, the technique applies a variation on the typical pentameter line causing it to appear at first glance as trochaic. Below, the anacrusis in the fourth line of William Blake's poem "The Tyger" (with punctuation modernized) is in italics:
The poem is in trochaic tetrameter, in which the first syllable of each line is expected to be stressed, but the fourth line begins with the additional unstressed syllable "Could".
Music
In music, an anacrusis (also known as a pickup, or fractional pick-up) is a note or sequence of notes, a motif, which precedes the first downbeat in a bar in a musical phrase. "The span from the beginning of a group to the strongest beat in the group." Anacrusis, especially reoccurring anacrusis (anacrusis motif played before every measure or every other measure), "is a common means of weighting the first beat," and thus strengthening or articulating the meter.
The term is borrowed from the terminology of poetry. Anacruses may involve fine details such as rhythm and phrasing or may involve wider features such as musical form (such as when used repeatedly).
The anacrusis is a perceived grouping which is context generated in the individual phrasing of a concrete composition. The grouping of one or more antecedent tone events to a perceived phrase gestalt may be rhythmically evoked by their temporal proximity to the phrase's first downbeat (perceived phrase onset).
Although the anacrusis is integrated in a musical phrase gestalt (grouped to it), it is not located in the perceived 'body' of the phrase (which is spanning from its first downbeat to its ending beat) but before the phrase (hence the German term "Auftakt"; literally: "upbeat"). In this respect – in a sequence of phrases – the anacrusis also may be perceived 'between' two phrases, neither being perceived as part of the ending of a former one, nor being located in the following one.
Outside of that the term of the anacrusis is most commonly used where it applies everywhere else 'within' the 'body' of the phrase between the 'head' (first downbeat) and the 'foot' (ending beat) where, by what ever musical means, a grouping is perceived from an upbeat to a downbeat (especially also to the phrases ending beat).
Since an anacrusis "is an incomplete measure that allows the composition [or section or phrase] to start on a beat other than one," if an anacrusis is present, the first bar after the anacrusis is assigned bar number 1, and Western standards for musical notation often include the recommendation that when a piece of music begins with an anacrusis, the notation should omit a corresponding number of beats from the final bar of the piece, or the final bar before a repeat sign, in order to keep the length of the entire piece at a whole number of bars. This final partial measure is the complement. However, an anacrusis may last an entire bar.
Examples
In the song "Happy Birthday to You", Happy is the anacrusis and the accent is on the first syllable of Birthday.
In "The Star-Spangled Banner", the word O! in the first line is an anacrusis in the music:
{| style="text-align: center;"
| x || / || x || x || / || x || x || / || x || x || / || ||
|-
| O!||say||can||you||see,||by|| the||dawn's||ear-||ly ||light||. . .
|}
At the beginning of the Beatles' "Yellow Submarine", "In the" is the anacrusis, while "town" falls on the downbeat.
Other fields
In academic publishing, the term is sometimes used in an article to mark an introductory idea standing between the abstract and the introduction proper.
See also
Caesura
Catalexis
Count off
Prosody (music)
Scansion
Tacet
References
Greek words and phrases
Poetic rhythm
Rhythm and meter | Anacrusis | Physics | 1,169 |
2,030,218 | https://en.wikipedia.org/wiki/Witches%27%20stones | Witches' stones (in Jèrriais: pièrres dé chorchièrs) are flat stones jutting from chimneys in the islands of Jersey and Guernsey.
According to folklore in the Channel Islands, these small ledges were used by witches to rest on as they fly to their sabbats. Householders would provide these platforms to appease witches and avoid their ill favour.
Traditional vernacular architecture in Jersey is in granite and such witches' stones can be seen protruding from many older houses. The real origin of this architectural feature is to protect thatched roofs from seeping water running down the sides of the chimney stack. Thatched roofs being thicker than tiled roofs, the jutting stones would sit snugly on the thatch – as can be seen on the few remaining thatched roofs in Jersey. When thatch began to be generally replaced by pantiles in the 18th century, and later by slates, the witches' stones were left protruding prominently from the chimney stack. This either gave rise to the belief in witches' resting places, or reinforced an existing belief. Fear of witches was widespread in country areas well into the 20th century in Jersey.
The force of tradition can be seen in a number of newly constructed houses in vernacular style that sport witches' stones despite never having had a thatched roof.
In England
Although not common in England, witch stones or witch seats can be found in the villages of Feizor, near Settle, and at Wharfe both in North Yorkshire.
See also
Architecture of Normandy
Adder stones, which are also called witches' stones
References
Des pièrres dé chorchièrs
Stonemasonry
Culture of Jersey
Witchcraft in England
Architectural elements | Witches' stones | Technology,Engineering | 336 |
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